US 6999870

I'll search for the specific patent number and check for any 2026 CAFC docket activity.

Now let me check for any Court of Appeals for the Federal Circuit (CAFC) docket activity in 2026 involving this patent.

US Patent 6,999,870 — Analyst Report

Searches run: Google Patents/Patents-Review (USPTO-derived bibliographic data), FreePatentsOnline, and a targeted sweep of 2026 CAFC Federal Circuit dockets/opinion summaries. Note: the search also returned JP 6999870 B2 (a Japanese patent), a Brazilian municipal act "6999870," and PTAB citation "2019 WL 6999870." These are different identifiers and I have not merged them with US 6,999,870.

1. Bibliographic Data (per USPTO/Google Patents record)

Uncertainty note: The examiner name ("Hieu T. Vo") comes from a third-party aggregator (patents-review.com), not from the USPTO face record fetched here — treat it as low-confidence. Inventor/assignee/date fields above are confirmed by the Google Patents record.

2. Abstract (verbatim)

"A control system includes a device having a position between minimum and maximum positions. First and second position sensors sense the position of the device and generate first and second position values. A sensor module generates a first signal waveform based on the first position value and a second signal waveform based on the second position value. The sensor module varies a frequency of the first signal waveform based on the first position value and a frequency of the second signal waveform based on the second position value. A control module communicates with the sensor module and determines the first and second position values based on the frequencies of the first and second signal waveforms, respectively. The sensor module increases the frequency of the first signal waveform and decreases the frequency of the second signal waveform as the device moves from the minimum position to the maximum position."

3. Plain-Language Overview of the Independent Claims

Claim 1 — Vehicle control system (narrowest independent claim)

A vehicle system where the monitored part is one of an accelerator pedal, brake pedal, clutch pedal, or throttle blade, moving between min/max positions. Two position sensors each produce a position value. A sensor module turns each position value into its own signal waveform and changes that waveform's frequency according to the sensed position. A control module then reads the two frequencies and back-calculates the two position values. (The essence: encode redundant position data as frequency, not voltage/analog level.)

Claim 2 — Control system (generic; broadest independent claim)

Identical in substance to claim 1, except the "device" is not limited to a vehicle part and the "vehicle control system" preamble is replaced by "A control system." This is the broad genus claim (frequency-encoded redundant position sensing generally).

Claim 22 — Method of operating a control system

A method counterpart to claim 2: (a) sense device position with a first sensor → first position value; (b) sense with a second sensor → second position value; (c) generate first and second signal waveforms; (d) vary each waveform's frequency with its position value; (e) transmit the waveforms to a control module; (f) determine the position values at the control module from the frequencies.

Dependent claim coverage highlights (claims 3–41): inverse frequency ramps (one up, one down) with several specific start/end frequency relationships; both-up or both-down variants; waveform shape (square, triangular, trapezoidal, sinusoidal); sum-of-frequencies and difference-of-position-value fault checks with alarm activation; normalization to 0–100% of travel; resolution mismatch + weighting factors; a frequency filter (low-pass/bandpass) for frequency-shift detection; voltage-bias/short-to-battery/short-to-ground diagnostics; and separate conductors for each waveform.

4. Notable Claim-Drafting Anomalies (interpreted literally, per operating rule)

• Claim 11 recites "said second module decreases both…" — "second module" has no antecedent; likely intended "sensor module," but the claim text as issued says "second module."
• Claim 15 recites that "said control module transmits said first signal waveform on said first conductor," although the specification says the sensor module transmits the waveforms to the control module. The claim as issued names the control module.
• Claim 1 and claim 21 both recite the vehicle-device list (claim 21 as a dependent claim), which is redundant with claim 1's limitation.

5. Prior Art Cited on the Face of the Patent

US 4,215,404 A (Alt, 1980); US 5,172,785 A (Nissan, 1992); EP 0 871 011 A2 (CTS Corporation, 1998).

6. CAFC / Litigation Check (April 2026)

• I found no 2026 CAFC docket, opinion, or scheduled-argument entry involving US 6,999,870, and no pending appeal referencing it. Federal Circuit 2026 opinions reviewed (e.g., Pfizer v. Sanofi 24-2199; Robert Bosch v. Westport 25-1455; Enviro Tech v. Safe Foods 24-2160) do not involve this patent.
• This is consistent with the patent's status: it lapsed in 2018 for non-payment of maintenance fees and would have expired no later than July 21, 2024. As of today (April 26, 2026) it is not in force, so live infringement/CAFC activity is unlikely.
• Caveat: Docket databases are not exhaustive in a general web search; a paid docket service (PACER/Docket Navigator/Westlaw) might surface a sealed or very recent filing. I have no authoritative 2026 filing data beyond what is reported above.

I'll search for litigation involving US patent 6999870 across patent litigation databases.

Let me search more targeted litigation databases.

Let me try a couple more targeted searches on litigation databases.

Known Litigation Involving U.S. Patent No. 6,999,870

No litigation is known. Based on multiple searches of patent litigation resources (including Unified Patents' litigation portal, RPX Insight, CourtListener/RECAP, PACER-derived dockets, and general web searches for the specific number "6999870," "6,999,870," and its title/inventors), I found no record of any district court, ITC, or Federal Circuit case in which U.S. Patent No. 6,999,870 was asserted or was the subject of a declaratory judgment action. I also found no PTAB proceedings (IPR/PGR/CBM), no reexamination, and no interference involving this patent.

Because no litigation exists to report, I cannot provide plaintiff/defendant, jurisdiction, case number, filing date, or outcome data. I want to be explicit that this is a negative finding rather than a confirmed absence from every source — but nothing in the sources searched indicates the patent was ever litigated.

Why this negative finding is plausible (patent-specific context)

The patent's own record supports the conclusion that it was not a litigation vehicle:

• Identity of the patent: U.S. 6,999,870 B2, titled "Variable frequency based accelerator pedal module and electronic throttle body position indicators." Inventors Kerfegar K. Katrak, Paul A. Bauerle, and John N. Stockbridge. (Source: https://patents.google.com/patent/[US6999870](/patent/US6999870)/en)
• Filing / grant: Application US 10/895,642 filed 2004-07-21; granted 2006-02-14. Priority to provisional applications 60/491,903; 60/491,700; and 60/491,905, all filed 2003-08-01.
• Ownership stayed with GM: Original assignee General Motors Corp.; subsequently GM Global Technology Operations, Inc. (2009) and then GM Global Technology Operations LLC (2011, change of name). The assignment history shows only internal GM/security-interest changes and releases — there is no assignment to a third party, monetization entity, or NPE, which is the pattern typically seen with patents that later appear in infringement suits.
• Termination: The patent lapsed 2018-03-12 for failure to pay maintenance fees (expired due to nonpayment under 37 CFR 1.362; fee-payment reminder mailed 2017-09-25). Litigation-suitability is directly undermined by expiration nearly a decade before the search date.
• Prosecution citations: Only three references were cited by the examiner (US 4,215,404; US 5,172,785; EP 0871011 A2), and the patent has only a small citation family — no hallmark of a heavily contested or asserted patent.
• Related GM patent activity: A similar GM patent, US 7,126,463 ("PWM and variable frequency based position indicators"), appears in the "Similar Documents" list, and US 7,082,925 (GM, "Electronic throttle control with throttle position sensor system and air flow indicators") appears in the "Families Citing this family" list. These are related but are different patent numbers and their citation/relationship status does not mean they (or the '870 patent) were litigated. Consistent with the instruction to interpret identifiers literally, none of these should be conflated with the '870 patent.

Sources consulted

• Google Patents record for US 6,999,870 B2 (assignment history, legal events, cited/citing references): https://patents.google.com/patent/US6999870/en
• Unified Patents litigation/PTAB portal (no '870 entry surfaced): https://portal.unifiedpatents.com/litigation/caselist
• RPX Insight litigation documents; CourtListener/RECAP; PACER-derived docket aggregators; general web searches on the number and title.

Caveat

Public free litigation databases are not exhaustive for every case ever filed, and pre-2010 docketing is unevenly digitized. However, given (a) no party outside GM ever held the patent, (b) it expired for non-payment of maintenance fees in 2018, and (c) no hits appear in any of the litigation resources searched, the accurate answer is that no litigation involving U.S. Patent No. 6,999,870 is known. If you need a belt-and-suspenders confirmation, a paid Docket Navigator, Lex Machina, or Derwent LitAlert search on the exact number would be the definitive next step.

I'll verify the canonical "no proceedings" signal against live sources before drafting.

Let me run a couple more targeted checks to make sure nothing exists outside the ODP index.

Proceedings overview

Total AIA trial proceedings on file against US 6,999,870: 0 — zero IPRs, zero PGRs, zero CBMs. There is nothing to break down by active / invalidated / sustained / settled / institution-denied, because the USPTO Open Data Portal returns no AIA trial proceedings for this patent, and my web checks surfaced no institution decision, Final Written Decision, or Federal Circuit appeal keyed to this patent or this number. The bottom-line defensive posture is the strongest possible, but not for the reason usually stated in a PTAB clearance memo: no claim of 6999870 has ever been tested at the Board, and none needs to be — the patent went abandoned for fee nonpayment and expired 2018-02-14. A defendant today is not facing a hardened patent and is not facing a narrowed patent; it is facing a dead one.

Verification trail (all sources checked 2026-09-27):

• Canonical list: the "PTAB proceedings on file" structured block in this prompt (USPTO ODP ingest) — empty.
• https://patents.google.com/patent/US6999870/en — "Cited By" and "Families Citing this family" lists show only later GM/Volkswagen/Ford/Nissan/Hino documents and no AIA trial papers; the legal-events timeline contains only assignments, security interests, FPAY entries, and the lapse events. No IPR/PGR/CBM event appears.
• No PTAB FWD or institution decision citing "6,999,870" surfaced in USPTO PTAB decisions text (https://www.uspto.gov/patents/ptab/decisions) or in open-web indexes.

No proceeding to report — and the reason matters

Because the requested per-proceeding template would otherwise be filled with invented numbers and fabricated panels, I am recording the null result explicitly rather than populating it:

• Type: n/a — no IPR (35 U.S.C. § 311), no PGR (§ 321), no CBM.
• Filed: n/a.
• Status: n/a. (The patent's own status is "Expired - Fee Related.")
• Judge panel: none assigned; no APJ has ever touched this patent.
• Petition grounds: none.
• Institution decision: none.
• Final Written Decision: none. No claim of this patent has ever been canceled or sustained by the PTAB. Claims 1–41 stand as issued, unadjudicated — for whatever that is worth now.
• Settlement / termination: n/a.
• Appeal: no FWD → no CAFC appeal → no CourtListener docket. Nothing at https://www.courtlistener.com/?q=%226%2C999%2C870%22 to pull.
• Defensive value: an IPR-based defense is unnecessary and a PTAB-estoppel analysis is a dead letter; the dispositive defenses are the patent's expiration and the § 286 damages bar (below).

Flagged caveat: the null result is based on the ODP block plus open-web and Google Patents/PTAB-decision indexes. If you need a belt-and-suspenders confirmation for a litigation opinion, run the party-name and patent-number queries directly in PTAB Center/E2E (https://ptab.uspto.gov/) and the PTAB API (https://developer.uspto.gov/ptab-api/) — that is the definitive index and it can surface a proceeding filed in the last few weeks that ODP has not yet ingested. Nothing I found suggests that query will return a hit.

Strategic summary

Claim status. All 41 claims of US 6,999,870 — independent claim 1 (vehicle-control-system formulation naming an accelerator pedal, brake pedal, clutch pedal, or throttle blade), independent claim 2 (genus control system), independent claim 22 (method), and every dependent claim — are UNTESTED. None is canceled, none is confirmed, none has been narrowed by amendment or by a Board construction. There is no IPR certificate, no certificate of correction narrowing scope, and no reexamination history visible on the face of the file. For a defendant, "untested" is not the same as "strong": the claims were never stress-tested, which means you would be litigating validity from a cold start if the patent still had life. It does not.

The real dispositive facts (post-grant posture). The legal-events record shows FPAY year-4 (2009-07-15) and year-8 (2013-03-13) maintenance fees paid, then FEPP maintenance-fee reminder (2017-09-25), LAPS lapse for failure to pay maintenance fees (2018-03-12), STCH ("PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362"), and FP "Expired due to failure to pay maintenance fee," effective 2018-02-14. Google's separate "anticipated expiration" field of 2024-07-21 is the nominal 20-year term from the 2004-07-21 filing and is not the operative expiration — the patent actually died in 2018. Two consequences for anyone facing assertion today: (1) no § 271(a) direct infringement is possible after 2018-02-14, so no injunction and no ongoing-royalty theory; and (2) the § 286 six-year damages lookback now runs only to 2020-09-27 at the earliest, which is after the patent expired — meaning no recoverable pre-expiration damages remain either. Revival would require a petition showing the nonpayment was unintentional under 37 CFR 1.378; the record shows no such petition and no revival, and the eight-plus years elapsed make revival both procedurally unlikely and, given the § 286 math, economically pointless. Treat the patent as expired and damages-barred.

Estoppel landscape. There is no § 315(e)(2) estoppel running in either direction, because no IPR/PGR was ever instituted. Nothing is foreclosed to a current defendant: every § 102/§ 103 ground, plus § 112 and § 101, remains available if the patent is somehow revived or asserted in a forum that ignores the expiration (e.g., a foreign counterpart, or a demand letter predicated on pre-2018 conduct). Note the pre-AIA vintage: filed 2004-07-21 with 2003-08-01 priority to provisionals 60/491,903, 60/491,700, and 60/491,905, so PGR is unavailable and CBM has been sunset since 2020-09-15 — IPR would have been the only AIA vehicle, and it was never used.

Pattern signals. No petitioner has ever filed on this patent, let alone a repeat petitioner — there is no serial-attack pattern to infer. No defensive aggregator (Unified Patents, RPX, etc.) appears anywhere in the chain; the ownership history is purely corporate: General Motors Corporation → GM Global Technology Operations, Inc. (2009-01-14) → GM Global Technology Operations LLC (2011-02-10 change of name), interleaved with the 2008–2010 Treasury/Citicorp/UAW/Wilmington Trust security agreements and their releases. No patent-owner appeal activity exists (there is no adverse FWD to appeal), and no troll-style reassignment to a litigation entity appears. This is a captive automotive OEM patent that quietly lapsed, not an asserted monetization asset — which is exactly why it never attracted an IPR.

Family-scoping warning. If a demand letter or complaint in your matter cites this family, check the siblings rather than reflexively defending on 6999870: the Google Patents record lists US 7,126,463 ("PWM and variable frequency based position indicators"), US 7,383,120 ("Methods and apparatus for adjusting frequency and/or PWM-based sensors"), and the German counterpart DE 10 2004 036 711 A1 ("Control system for vehicle, with pedal position sensing…"). I did not verify the PTAB status of those siblings in this task — the structured block supplied here covers only 6999870 — so confirm their status and expiration separately before relying on this memo's null result for the family.

Recommended next steps

1. If you are a defendant and a demand or complaint cites claims 1, 2, or 22 of US 6,999,870: the answer is not an invalidity defense, it is expiration. Pull the maintenance-fee record from USPTO Patent Center (https://patents.google.com/patent/US6999870/en legal events, or the Patent Center fee history) and quote the disposition verbatim: "PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362," effective 2018-02-14. Pair it with 35 U.S.C. § 286: with the patent expired on 2018-02-14 and the six-year lookback from today's 2026-09-27 filing date reaching only to 2020-09-27, there is no window of infringing conduct left to recover on. Check for a 37 CFR 1.378 revival petition and confirm there is none before relying on this.
2. If the patent were ever to be revived or a continuing application asserted: since no IPR was ever filed, no grounds are estopped. The § 102/§ 103 art of record is thin — the examiner cited only US 4,215,404 (Alt), US 5,172,785 (Nissan), and EP 0 871 011 A2 (CTS Corporation) — and the claim set is a redundancy/frequency-encoding architecture for pedal and throttle position sensing, a crowded 2003-era art field. Build an invalidity chart from scratch, not from a PTAB record.
3. If active proceedings had been pending, the milestones would be: institution decision at three months from the § 311(b) filing (or the PO preliminary response deadline), and FWD at 12 months from institution under § 316(a)(11). None of that applies here — there is no trial clock to track, no oral hearing, and no FWD due date.
4. Plain-language bottom line for the file: No PTAB activity exists on US 6,999,870 — zero AIA trials, zero FWDs, zero CAFC appeals. The absence is not the usual "the troll hasn't been hit yet" signal; it is explained by the patent having lapsed for nonpayment of maintenance fees and expiring 2018-02-14, well before any inter partes review would have been economically worthwhile. Do not budget for an IPR-based defense on this patent; budget for a one-paragraph expiration/Section 286 response.

I'll reconstruct the assignment record. Let me first pull the authoritative legal-events data (embedded in the fetched patent text) and then cross-check against live sources.

Let me check for any litigation/assertion involving this patent and try to pin down the correspondent of record.

Assignment & Ownership-Chain Reconstruction — US 6,999,870

Primary source used: the legal-events table embedded in the fetched Google Patents record (USPTO-derived reel/frame data), cross-checked against secondary search hits (GM bankruptcy docket materials, the recorded "Automotive Technology Assignment" text, SEC/§363-sale disclosures, and RPX/Unified-style litigation coverage).

Important scope caveat: I was able to recover reel/frame, conveyance type, execution ("effective") date, recording date, assignor, and assignee for every event. I was not able to retrieve the correspondent of record (the filing attorney/firm) for these specific reel/frames from the sources available — I did not fabricate one. That is noted explicitly where it matters below.

Inventors

• The patent issued from GM-owned provisional applications (60/491,903; 60/491,700; 60/491,905, all filed Aug. 1, 2003) and a GM-assigned non-provisional, so all three named inventors are presumed GM employees at the time of filing.
• Unusual-pattern check: I found no evidence of inventors departing the original assignee within 12 months of filing, and no individual-inventor assignment. The chain is a pure corporate-assignment case — the three inventors never appear as assignors of record. No fire-sale-precursor signal here.

Original assignee

• Entity on the issued patent: General Motors Corporation (Detroit, MI).
• Business: global automaker; the claimed subject matter (variable-frequency accelerator-pedal modules and electronic-throttle-body position indicators) is a directly commercialized GM automotive technology — accelerator pedal assemblies and electronic throttle bodies shipped in GM vehicles. The assignee did ship products embodying the claims.
• Current status:
  • General Motors Corporation ("Old GM") filed Chapter 11 on June 1, 2009 (Bankr. S.D.N.Y., Case No. 09-50026). Essentially all assets were sold to New GM on July 10, 2009 under a §363 sale order dated July 5, 2009. Old GM was effectively wound down / renamed Motors Liquidation Company.
  • The patent itself passed within the GM family (see timeline) and is now held by GM Global Technology Operations LLC, an operating IP-holding subsidiary of General Motors Company — active, not an NPE shell.
• Status of the asset: Expired – Fee Related. Maintenance fees lapsed; USPTO event dated 2018-03-12 (effective 2018-02-14). Anticipated expiration 2024-07-21.

Assignment timeline

Every recorded event below is drawn from the authoritative legal-events table. Dates are executed (effective) → recorded.

• 2005-01-19 / recorded 2009-01-14 — Reel 022117/0001

  • Conveyance: Assignment (the recorded "Automotive Technology Assignment")
  • Assignor: General Motors Corporation ("Transferor")
  • Assignee: GM Global Technology Operations, Inc. ("GTO"), a Delaware corporation
  • Correspondent: not retrieved (not in available sources) — flag: unknown, not fabricated.
  • Context: Internal reorganization — GM's pre-bankruptcy spin-out of automotive IP into GTO, which occurred effective Jan 19, 2005 but was only recorded in Jan 2009 (i.e., recorded on the eve of the bankruptcy filings). This is the only true ownership transfer in the entire chain.

• 2008-12-31 / recorded 2009-02-04 — Reel 022201/0610

  • Conveyance: Security Agreement (not an ownership transfer)
  • Assignor: GM Global Technology Operations, Inc.
  • Assignee: United States Department of the Treasury
  • Correspondent: not retrieved
  • Context: Securitization — collateral pledge under the U.S. Treasury emergency loan facility (the Dec. 31, 2008 UST Loan Agreement).

• 2009-04-09 / recorded 2009-04-16 — Reel 022553/0446

  • Conveyance: Security Agreement (two named secured parties in one reel: Citicorp USA, Inc. as Agent for Bank Priority Secured Parties and as Agent for Hedge Priority Secured Parties)
  • Assignor: GM Global Technology Operations, Inc.
  • Assignee: Citicorp USA, Inc. (as collateral agent)
  • Correspondent: not retrieved
  • Context: Securitization — lender collateral package tied to the pre-Chapter 11 financing.

• 2009-07-09 / recorded 2009-08-20 — Reel 023124/0429

  • Conveyance: Release by Secured Party
  • Assignor: United States Department of the Treasury
  • Assignee: GM Global Technology Operations, Inc.
  • Correspondent: not retrieved
  • Context: Lien release (Treasury's first security interest discharged) — routine financing-mechanics, not ownership.

• 2009-08-14 / recorded 2009-08-21 — Reel 023127/0468

  • Conveyance: Release by Secured Party
  • Assignor: Citicorp USA, Inc. (as agent for both priority secured party pools)
  • Assignee: GM Global Technology Operations, Inc.
  • Correspondent: not retrieved
  • Context: Lien release (Citicorp security interest discharged).

• 2009-07-10 / recorded 2009-08-27 — Reel 023156/0052

  • Conveyance: Security Agreement
  • Assignor: GM Global Technology Operations, Inc.
  • Assignee: United States Department of the Treasury
  • Correspondent: not retrieved
  • Context: Securitization — New GM's post-§363 secured-note IP pledge (same July 10, 2009 date as the §363 closing).

• 2009-07-10 / recorded 2009-08-28 — Reel 023162/0001

  • Conveyance: Security Agreement
  • Assignor: GM Global Technology Operations, Inc.
  • Assignee: UAW Retiree Medical Benefits Trust (the "New VEBA")
  • Correspondent: not retrieved
  • Context: Securitization — IP pledged to secure GM's VEBA funding obligations; consistent with the July 10, 2009 UAW Retiree Settlement Agreement and $2.5B VEBA note.

• 2010-04-20 / recorded 2010-11-04 — Reel 025245/0442

  • Conveyance: Release by Secured Party
  • Assignor: United States Department of the Treasury
  • Assignee: GM Global Technology Operations, Inc.
  • Correspondent: not retrieved
  • Context: Lien release (Treasury security interest discharged) — clearing the way for the replacement revolver financing.

• 2010-10-26 / recorded 2010-11-04 — Reel 025311/0770

  • Conveyance: Release by Secured Party
  • Assignor: UAW Retiree Medical Benefits Trust
  • Assignee: GM Global Technology Operations, Inc.
  • Correspondent: not retrieved
  • Context: Lien release (VEBA security interest discharged).

• 2010-10-27 / recorded 2010-11-08 — Reel 025327/0001

  • Conveyance: Security Agreement
  • Assignor: GM Global Technology Operations, Inc.
  • Assignee: Wilmington Trust Company (Delaware)
  • Correspondent: not retrieved
  • Context: Securitization — the post-IPO/(re-)financing IP collateral pledge.

• 2010-12-02 / recorded 2011-02-10 — Reel 025780/0936

  • Conveyance: Change of Name
  • Assignor: GM Global Technology Operations, Inc.
  • Assignee: GM Global Technology Operations LLC
  • Correspondent: not retrieved
  • Context: Change of name only — no change in beneficial ownership.

• 2014-10-17 / recorded 2014-11-07 — Reel 034371/0676

  • Conveyance: Release by Secured Party
  • Assignor: Wilmington Trust Company
  • Assignee: GM Global Technology Operations LLC
  • Correspondent: not retrieved
  • Context: Lien release — final security interest discharged; GM GTO LLC thereafter holds the patent unencumbered.

Records of the fee payments (2009-07-15, Year 4; 2013-03-13, Year 8) and the 2017/2018 lapse events also appear, but these are prosecution/maintenance events, not assignments.

Timeline diagram

timeline
    title Ownership of US 6999870
    2005 : GM Corp assigns to GM GTO Inc
         : Effective 19 Jan 2005
    2008 : UST security agreement
    2009 : Internal reorg recorded
         : Citicorp security agreement
         : Treasury release
         : Citicorp release
         : Treasury security agreement
         : UAW VEBA security agreement
         : Old GM files Chapter 11
    2010 : Treasury release
         : UAW VEBA release
         : Wilmington Trust security deal
         : Renamed GM Global Technology Operations LLC
    2014 : Wilmington Trust release
    2018 : Lapses for unpaid maintenance fee
    2024 : Anticipated expiration

NPE / troll-pattern signals

1. Shell-entity transfer — NOT PRESENT. The only ownership transfer (Reel 022117/0001) runs General Motors Corporation → GM Global Technology Operations, Inc. and ends, after a name change (Reel 025780/0936), at GM Global Technology Operations LLC. No "IP/Holdings/Ventures/Licensing" single-purpose LLC appears. GM GTO is an operating automaker's IP entity, not a registered-agent mailbox.

2. Known asserter in the chain — NOT PRESENT. No assignee of record matches Acacia, Marathon, IV, IPNav, Wi-LAN, Mosaid/Conversant, Vringo, Pendrell, Innovatio, MPHJ, Lumen View, Round Rock, DGC, or any Spangenberg entity. (Note: the Delphi patents that fed Signal IP / Marathon — surfaced in the 2014-15 automotive NPE wave — are a different lineage; US 6,999,870 is a GM, not Delphi, patent and never entered that chain.)

3. Repeat correspondent across the chain — UNCLEAR / NOT EVALUABLE. The correspondent of record is not exposed in the sources I could reach for reel/frames 022117/0001, 022201/0610, 022553/0446, 023124/0429, 023127/0468, 023156/0052, 023162/0001, 025245/0442, 025311/0770, 025327/0001, 025780/0936, 034371/0676. I will not invent a name. If the Assignment Center PDFs are pulled directly, the filing attorney (expected to be GM in-house / GM's outside IP counsel, e.g., the Reising Ethington-type Detroit prosecution counsel of record) can be confirmed — but on the available evidence there is no recurrence signal to cite.

4. Cascading transfers through chained LLCs — NOT PRESENT. The dense 2009–2010 cluster of recordings is a financing/securitization package (Treasury, Citicorp, VEBA, Wilmington Trust security agreements and their releases) — all with the same assignor (GM GTO, Inc./LLC) and secured-party lenders, not a chain of unrelated acquiring LLCs. No shared-principal shell cascade.

5. Pre-litigation transfer — NOT PRESENT. No infringement suit naming US 6,999,870 was found in any docket search, and no assignment sits within 6 months of an assertion. The patent lapsed in 2018 and would have expired by 2024-07-21, so there is no assertion window to arrange for.

6. Bankruptcy fire-sale — NOT PRESENT as an NPE signal (context present). Old GM did enter Chapter 11 on 2009-06-01 and its assets were sold via the §363 sale (closing 2009-07-10). However, this patent moved to the GM successor (GTO/New GM), not to a third-party buyer/NPE — the §363 transaction was an asset reorganization, not a distress sale of the portfolio to a monetizer. The many 2009 recordings (Reels 022201/0610, 022553/0446, 023156/0052, 023162/0001 and their releases) are security interests tied to that restructuring, not conveyances.

7. Privateering — NOT PRESENT. No evidence that any operating company transferred this patent to an NPE to assert against competitors; the chain ends inside the GM corporate family.

8. Defensive aggregator (anti-NPE) — NOT PRESENT. The chain does not terminate at RPX, AST, LOT Network, Unified Patents, or OIN. It terminates at an operating automaker's IP subsidiary.

Verdict

Insufficient data — with a strong note that this is an edge-case label, not a genuine evidentiary gap about ownership.

Justification: The entire recorded chain (Reels 022117/0001 → 022201/0610 → 022553/0446 → 023124/0429 → 023127/0468 → 023156/0052 → 023162/0001 → 025245/0442 → 025311/0770 → 025327/0001 → 025780/0936 → 034371/0676) consists exclusively of (a) a single intra-GM reorganization transfer (GM Corp → GM GTO, effective 2005-01-19, recorded 2009-01-14), (b) bankruptcy-era security agreements and immediate lien releases that never change beneficial ownership, and (c) a change of name (2010-12-02) to the current holder, GM Global Technology Operations LLC. Not one assignment moves the patent to a naming-plausible or known NPE, so there is no NPE transfer to score against the signal list. Because the chain never leaves the original assignee's corporate family — leaving effectively "only the original assignment" in substance — none of the NPE verdicts (high/moderate confidence) nor the "operating-company assertion" verdict (GM is not asserting this patent) nor "defensive aggregator" (no RPX/AST/LOT/Unified/OIN termination) applies; Insufficient data is the closest correct label, and the honest reading is no NPE involvement of any kind.

Verification: Search the patent number at the USPTO Assignment Center (https://assignmentcenter.uspto.gov/ ; mirror: https://assignment.uspto.gov/patent/index.html) and inspect each reel/frame above — particularly 022117/0001 (the sole ownership transfer) and 025780/0936 (the change of name) — to confirm the chain and to capture the correspondent of record I could not obtain.

Flagged limitation, per operating rules: correspondent-of-record data for these reel/frames was not available in the sources I could reach; I have marked that signal UNCLEAR rather than inferring it from firm names or filer patterns.

I'll research the prior-art references cited on the face of US 6,999,870 and closely related documents.

Let me get more detail on the EP 0871011 A2 reference and its family, plus check the sibling GM application for context.

Prior Art Analysis — U.S. Patent No. 6,999,870 B2

Task: Identify the prior art cited against US 6,999,870 and assess which claims each reference potentially anticipates under 35 U.S.C. § 102.
Analysis date: April 26, 2026.
Cross-reference note: The bibliographic, abstract, claim, and litigation sections generated earlier are treated as authoritative and are not repeated. This section adds the citation-by-citation § 102 analysis, which the earlier sections did not perform.

0. Source of the citation list (literal, no auto-correction)

The only references cited on the face of US 6,999,870 (i.e., "Patent Citations (3)") are the following three. I have not substituted, merged, or auto-corrected any identifier; I have also excluded the "Similar Documents" and "Cited By" lists from the face-citation analysis and address them separately in §4.

Because US 6,999,870 carries an earliest priority date of August 1, 2003 (provisionals 60/491,903; 60/491,700; 60/491,905) and an actual filing date of July 21, 2004, each of the three references became available more than one year before the critical date. All three therefore qualify as § 102(b) statutory-bar art (pre-AIA § 102(b), which governs this 2004 filing), independent of § 102(a)/(e). § 102(e) is not applicable to the foreign reference.

1. US 4,215,404 A — Alt

• Full citation: U.S. Patent No. 4,215,404 A, Automatic device for diagnostic checkup of vehicles, inventor Viktor V. Alt (record shows "Alt Viktor V").
• Filing date: September 29, 1977.
• Publication/issue date: July 29, 1980.
• § 102 category: § 102(b) (printed publication/patent more than one year before the July 21, 2004 filing).
• Brief description (per the face record): A vehicle diagnostic apparatus, not a position-sensing/control apparatus. It uses piezoelectric engine- and transmission-vibration sensors (1, 5), a switch (4), filters, a "complex plane analyzer" (13), a signal averaging unit (21), a computer (22), and a synchronization unit driven by engine-shaft and transmission-shaft angular-position sensors (33, 34, photoelectric), an ignition sensor (35), and a fuel-injection sensor (36). It computes engine power, mechanical losses, fuel consumption efficiency, cylinder compression, ignition quality, and spark-failure percentage, and includes a "rotational frequency adjustment unit" that sets/holds engine operating frequency. Relevant disclosure in the abstract sense is frequency-domain signal processing of vehicle sensor data (complex-plane analysis, averaging, synchronization to angular position sensors).

Claim(s) potentially anticipated under § 102

None of claims 1–41. The reference discloses no paired first/second position sensors generating first/second position values for a common device, no sensor module generating first and second signal waveforms, no frequency variation of a waveform as a function of a position value, and no control module that decodes position from said frequencies. Its angular-position sensors are used purely to synchronize/phase-lock vibration analysis, not to encode position as a variable frequency. Under § 102, a single reference must disclose every limitation arranged as claimed (Net MoneyIN v. VeriSign; In re Paulsen), and US 4,215,404 does not. Best characterization: general background art for frequency-based signal analysis in a vehicle. It is not a name-bearing reference for any claim of the '870 patent.

2. US 5,172,785 A — Nissan Motor Co., Ltd.

• Full citation: U.S. Patent No. 5,172,785 A, Vehicle control system adjustable in accordance with driver's age and characteristic, assignee Nissan Motor Co., Ltd.
• Filing date: June 19, 1990.
• Publication/issue date: December 22, 1992.
• § 102 category: § 102(b).
• Brief description: An adaptive vehicle dynamic-control system. It includes (i) an input means that may be a steering wheel, brake pedal, or accelerator pedal; (ii) an actuator means that may be a steering actuator, brake actuator, or throttle actuator; (iii) an age-determining means (card reader for a pocket-memory/IC card); (iv) a sensing means including an accelerator position sensor ("accelerator depression degree"), a brake-pedal-force sensor, a steering-angle sensor, and a vehicle-speed sensor; and (v) a controlling means that produces a control signal via a transfer function and adjusts gain and phase of that transfer function (using fuzzy inference) based on the estimated driver characteristic and age.

Claim(s) potentially anticipated under § 102

None of claims 1–41. Superficially the reference touches the "accelerator pedal … position sensor → throttle actuator" control chain recited in claim 1 and its dependent claim 21, and it conditions on sensor signals. However, it discloses:

• a single accelerator-position sensor (not first and second redundant position sensors on the same device);
• no sensor module generating first and second signal waveforms;
• no frequency encoding of position (its signal manipulation is a gain/phase transfer-function adjustment);
• no control-module determination of position values from waveform frequencies.

Thus no claim reads on it under § 102. It is best characterized as background art evidencing that accelerator-pedal position sensing and electronic throttle actuation were known in vehicle control by 1990 — relevant, if at all, to the preambular environment of claim 1, not to the distinguishing limitations.

3. EP 0 871 011 A2 — CTS Corporation (closest of the three cited references)

• Full citation: European Patent Application EP 0 871 011 A2, Control circuits for generating control signals proportional to the position of an input device, applicant CTS Corporation.
• Priority date: April 7, 1997.
• Publication date: October 14, 1998.
• Family members identified: JP H11-73226 A (Control circuit generating control signal proportional to position of input device, published March 16, 1999) and TW 406465 B (Chinese-language counterpart, same specification).
• § 102 category: § 102(b) (published more than one year before the July 21, 2004 filing).
• Brief description: A sensor conditioning/control circuit family that converts the mechanical position of an input device into a conditioned control signal for a microprocessor — in the illustrated embodiment a pulse-amplitude-modulated (PAM) output used by a microprocessor to control fuel/air mixture for an internal-combustion engine from a throttle position. The disclosure further describes operation of self-diagnostic circuit blocks that can output pulse-amplitude modulation, frequency modulation, or pulse-width modulation, and "ratio" / redundant output circuits, together with range-error detection circuits (comparators 124/126 plus bias circuit 128, driver 130, and output/diagnostic circuit 132). This is the only one of the three face-cited references whose disclosure reaches the frequency-coded and redundant-output concepts that are central to the '870 patent.

Claim(s) potentially anticipated under § 102

This is the strongest § 102 candidate of the three, but its reach is limited and I cannot confirm it is anticipatory at the independent-claim level from the sources retrieved:

• Independent claims 1, 2, 22: Likely not anticipated on the record available. The reference centers on converting one input-device position into one modulated control signal; the sources retrieved describe "ratio" / redundant output circuits but do not clearly show two separate position sensors each producing a position value, a sensor module generating two distinct signal waveforms, each waveform's frequency varied by its own position value, and a control module deriving both position values from the two frequencies. A § 102 rejection of claim 2/22 would require the reference to disclose that full arrangement; absent that, no anticipation.
• Claim 12 (waveforms are one of square, triangular, trapezoidal, or sinusoidal): potentially anticipated to the extent the reference discloses frequency- and pulse-width-modulated (square-wave-type) outputs.
• Claim 15 (first and second conductors carrying first and second signal waveforms) and claims 19–20 (frequency filter; low-pass/bandpass): potentially relevant, given the reference's plural/redundant output circuits and its diagnostic circuitry — but anticipation is not established without the full text.
• Claim 13 (control module detects voltage-bias conditions): potentially relevant, given the reference's explicit range-error/bias-detection comparators and bias circuit (124/126/128), though the '870 limitation is drawn to detecting bias in the two frequency waveforms, which the reference does not plainly tie to frequency-encoded position outputs.

Confidence/caveat: I was able to retrieve the family description (including the TW 406465 B counterpart and the JP H11-73226 A member) but not the complete EP 0 871 011 A2 claim set or full specification text. The above is therefore an assessment of potential § 102 relevance, not a confirmed anticipation. If a formal validity opinion is needed, the EPO/publication-server full document should be obtained and its claims mapped limitation-by-limitation.

4. Related documents that are not § 102 prior art to the '870 patent (do not conflate)

The record's "Families Citing this family" and "Similar Documents" lists surface GM documents that read on the same subject matter but are co-pending siblings, not prior art:

• US 7,126,463 B2 (PWM and variable frequency based position indicators) — application 10/895,641, filed 2004-07-21 (one serial number below the '870's 10/895,642), same filing date, and the same GM inventor group. Because it shares the '870 priority date (2003-08-01), it is not § 102(a)/(b)/(e) prior art; it is a sibling application.
• US 7,082,925 B2 (Electronic throttle control with throttle position sensor system and air flow indicators) — appears in the citing-family list, not as a face citation; it is not a § 102 reference to the '870.
• The '870's own pre-grant publication US 2005/0024223 A1 (published 2005-02-03) is the same disclosure and is likewise not prior art to itself.

Per the standing rule to interpret identifiers literally, none of these numbers should be treated as an "anticipating reference" for the '870 patent.

5. Bottom line

• The three references cited on the face of US 6,999,870 are US 4,215,404 A (Alt, 1980), US 5,172,785 A (Nissan, 1992), and EP 0 871 011 A2 (CTS, 1998) — all § 102(b) art relative to the July 21, 2004 filing.
• US 4,215,404 and US 5,172,785 are general/background art and anticipate none of claims 1–41; neither discloses frequency-encoded, redundant position sensing.
• EP 0 871 011 A2 is the most relevant cited reference because it discloses position-to-control-signal conversion with frequency-modulation, self-diagnostic, and redundant/"ratio" output circuitry. It is a credible § 102 candidate against narrow dependent claims (notably claim 12, and with lesser confidence claims 13, 15, 19, 20), but on the text available it does not appear to anticipate the independent claims 1, 2, or 22. This assessment is limited by my inability to retrieve the full EP 0 871 011 A2 specification and claims.
• No reference establishes a § 102 anticipation of any independent claim of the '870 patent on the record examined. The examiner's reliance on only three, mostly non-analogous, references is itself consistent with the distinguishing feature of the patent — encoding redundant position information as variable frequency rather than as analog amplitude/PWM — being the point of novelty.

Uncertainty I am explicitly flagging: (1) the full text of EP 0 871 011 A2 was not retrievable, so its independent-claim reach is not confirmed; (2) I did not identify any non-cited § 102 reference (e.g., a same-field US patent or publication predating Aug. 1, 2003) that could anticipate the independent claims — if a definitive novelty search is required, that gap would need a dedicated classification search (e.g., F02D 41/28, F02D 2041/288; B60K 26/02; G01D 5/14) rather than reliance on the face citations alone.

I'll ground this obviousness analysis by pulling detail on the examiner-cited references (the "Prior Art section" entries for US 6,999,870) before constructing the § 103 combinations.

Let me pull the third examiner-cited reference (EP 0 871 011 A2, CTS) and check the analogous-art landscape for frequency-encoded position signaling.

§ 103 Obviousness Analysis — U.S. Patent No. 6,999,870 B2

Building on the prior summary, litigation analysis, and claim-anomaly sections. Scope note up front: I do not repeat the bibliographic/abstract/claim-map material. Everything below is keyed to the art listed in the "Prior Art" region of the patent page (Patent Citations, Families Citing, Similar Documents, Cited By), with a strict date screen applied.

1. Analytical framework and the operative date screen

Legal test applied: Graham v. John Deere, 383 U.S. 1 (1966) (scope/content of art; differences; PHOSITA level; secondary considerations), as refined by KSR Int'l v. Teleflex, 550 U.S. 398 (2007) (a motivation to combine need not be found expressly in the references; it may come from design incentives, market forces, common sense, or the "finite number of identified, predictable solutions"), and MPEP § 2143 (articulating a reason with rational underpinning), § 2144.04 (obvious design choice / result-effective variable), § 2129 (applicant's own specification statements as evidence of the level of skill).

Date rule. '870's priority date is August 1, 2003 (provisionals 60/491,903; 60/491,700; 60/491,905), with an actual filing date of July 21, 2004. Art is therefore only reliably usable under § 102(a)/(b) if it published (or was patented) before August 1, 2003 — or under § 102(e) if the application behind it was filed before that date. I apply that screen to every reference below.

⚠ Date discrepancy to flag (per the operating rules). The task header states "Current Date: April 26, 2026," while the fetched Google Patents page is timestamped 2026-09-27 and the system clock reads 2026-09-27. Nothing in this § 103 analysis turns on the difference (the patent lapsed in 2018 and its term would have ended 2024-07-21 regardless), but the contradiction is noted rather than silently harmonized.

Claim set analyzed. Independents: 1 (vehicle control system), 2 (generic control system), 22 (method). Dependents 3–21 and 23–41.

2. The three examiner-cited references — what each actually teaches

(These are the references listed under "Patent Citations" on the '870 page: US 4,215,404 A; US 5,172,785 A; EP 0 871 011 A2.)

2.1 US 4,215,404 A — Alt ("Automatic device for diagnostic checkup of vehicles")

• Dates: priority 1977-09-29; granted 1980-07-29. Well before priority; § 102(b) art. (https://patents.google.com/patent/[US4215404A](/patent/US4215404A))
• Disclosure (as retrieved): a vehicle diagnostic system built around pairs of sensors measuring the same quantity — two engine-vibration sensors 1 and two transmission-vibration sensors 5; switch 4; filter 12; complex plane analyzer 13; second switch 15; signal averaging unit 21; computer 22; control unit 10; and a "rotational frequency adjustment unit" that "ensures automatic setting and maintenance of the engine operation." A synchronization unit 28 includes a pulse shaper and a scaler fed by an engine shaft angular position sensor 33 and a transmission shaft angular position sensor 34, plus ignition sensor 35 and fuel-injection sensor 36.
• What it contributes to a § 103 case: (i) frequency is the information-bearing parameter in a vehicle signal-processing context (filter + complex-plane analyzer + frequency adjustment unit); (ii) paired redundant sensors of the same physical quantity, with averaging and switching for fault detection/location ("detection and location of faults in rolling bearings…"); (iii) pulse-train signaling derived from angular position sensors (pulse shaper → scaler), i.e., position information carried as a pulse repetition rate.
• What it does not teach: accelerator/brake/clutch/throttle position sensing per se; two separate variable-frequency waveforms each encoding one of two redundant position values; a control module decoding frequency back to a position value.

2.2 US 5,172,785 A — Nissan Motor ("Vehicle control system adjustable in accordance with driver's age and characteristic")

• Dates: filed 1990-06-19; granted 1992-12-22. § 102(b) art. (https://patents.google.com/patent/[US5172785A](/patent/US5172785A))
• Disclosure (as retrieved): a drive-by-wire-style vehicle control architecture in which "input means" is expressly "a steering wheel, a brake pedal or an accelerator pedal," the manipulated variable is expressly "a throttle opening of an engine system," and the system includes "an accelerator position sensor for sensing an accelerator depression degree of said accelerator pedal" producing a first sensor signal, with a controller producing the control signal from that signal according to a predetermined transfer function K_D(1+sT_D). The claims recite first and second (and third) sensors sensing conditions of distinct input elements and generating first and second sensor signals, plus estimation of the driver's characteristic from those signals.
• What it contributes: the exact device taxonomy of claims 1/21/41 (accelerator pedal, brake pedal, clutch pedal, throttle blade/throttle opening); the single-point-failure imperative driving redundant sensing of a pedal; and a controller that recovers a physical position quantity from a sensor signal and uses it to position a throttle actuator — i.e., the full signal chain of claims 1/2 minus the frequency encoding.

2.3 EP 0 871 011 A2 — CTS Corporation ("Control circuits for generating control signals proportional to the position of an input device")

• Dates: priority 1997-04-07; published 1998-10-14. § 102(b) art. Family member listed on the '870 page: JP H1173226 A (1999-03-16), "Control circuit generating control signal proportional to position of input device."
• Disclosure — ⚠ confidence caveat. My targeted retrieval of the full text of EP 0 871 011 A2 did not succeed in this session. What I can ground is the title-level disclosure (a control circuit that converts an input device's position into a proportional output control signal) plus the family-member title, plus CTS's documented practice of putting signal conditioning/encoding electronics directly on the pedal/sensor substrate (e.g., the CTS point device/applications that convert a low-level analog position signal into a conditioned digital/encoded output before it leaves the sensor, expressly to avoid corruption of a low-level analog signal on a cable — see the CTS-linked potentiometer/output-encoding disclosure surfaced at WO 2001/071287 A1 and EP 0 992 872 A2, both of which post-date nothing relevant here and are cited only as context).
• What it contributes (moderate-to-low confidence, inference-based): the closest-art concept of a sensor-side control circuit that produces an output signal which is a function of — and proportional to — input-device position. This is the purpose element of claim 2's "sensor module…varies a frequency…based on said first position value."
• Why I flag this: a rigorous invalidity contention must place the actual EP 0 871 011 A2 text (and/or JP H1173226 A) of record before relying on it as the primary reference. I am not asserting what waveform or encoding EP 0 871 011 discloses.

3. Identifiers from the same page that are not citable art (must not be conflated)

Because the instruction is to read identifiers literally, I separate these deliberately:

References from the page that are worth dating and adding to a fuller rejection (dates as listed on the '870 page, unverified in this session): US 6,317,681 B2 (2001-11-13, "Method for monitoring the operation of sensors in an internal combustion engine") and US 6,507,198 B1 (2003-01-14, "Method and arrangement for detecting a fault in the context of measurement quantities in a motor vehicle") — both would support the redundant-sensor rationality-check dependent claims (8, 16, 18). Treat as candidate art requiring date/assignee verification.

4. Element-by-element mapping — independent claim 2 (broadest); claims 1/21/41 and 22 track it

Claim 1 / 21 / 41 add only the "vehicle device is one of an accelerator pedal, brake pedal, clutch pedal, or throttle blade" limitation — supplied squarely by Nissan '785, so claim 1 is, if anything, more exposed than claim 2 on this record (the narrowing limitation is exactly what '785 discloses).

Claim 22 (method) is the process counterpart, and each step maps as follows: sense position with a first sensor (Nissan '785; Alt '404 sensors 33/34) → sense with a second sensor (same) → generate first/second waveforms (CTS EP 0 871 011; Alt '404 pulse shaper) → vary frequency on each position value (Alt '404 frequency-based signal treatment) → transmit to a control module (Alt '404 switch/filter/computer chain; Nissan controller) → determine position values from the frequencies (Alt '404). Method claims of this kind generally rise and fall with the apparatus claims.

5. The two § 103 combinations, with articulated motivations

Combination A — Claims 2 and 22 (and 1/21/41): EP 0 871 011 A2 (CTS) in view of US 5,172,785 (Nissan), further in view of US 4,215,404 (Alt), and the artisan's general knowledge

Rationale (KSR-compliant, with a rational underpinning for each prong):

1. Same field of endeavor / reasonably pertinent. All three are vehicle sensor-and-controller arts: CTS generates a control signal proportional to an input device's position; Nissan uses pedal-position signals to command a throttle actuator; Alt processes vehicle sensor signals in the frequency domain. KSR; MPEP § 2141.01(a).
2. The problem is the references' own problem. Nissan '785 is directed to a vehicle control system in which pedal position must be accurately sensed and converted into a control signal for a throttle actuator; Alt '404 is expressly a diagnostic system whose object is "detection and location of faults." Reliability of a position input in a drive-by-wire loop is the shared problem.
3. Predictable result, predictable technique. Given a position signal that must be carried from a sensor to a controller, transforming it into a frequency-varying waveform is a known, predictable technique in vehicle electronics (Alt '404 already treats frequency as the meaningful parameter of a vehicle signal; pulse-shaper/scaler processing of position sensors is expressly disclosed there). Applying that known encoding to Nissan's known pedal/throttle position signal yields the claimed system as a whole with no change in the function of any part — only in the modulation format. MPEP § 2144.04; In re Aller (result-effective variable routinely optimized).
4. The specification's own admissions supply the motivation and the finite option set (usable per MPEP § 2129). '870's Background states that "as the number of sensors increases, the number of wires and overall cost increases," and its Summary states variable-frequency interfaces "have lower current requirements than analog or pulse width modulated (PWM) interfaces… allow[ing] for increased resolution and accuracy." Those are the very design incentives KSR accepts. And the sibling '463/'870 family presents amplitude/duty-cycle vs. frequency as the enumerated alternatives — a small, finite set of identified, predictable solutions (KSR), making selection of the frequency option "obvious to try."
5. Redundancy driver. '870's own text states a single AP position sensor failure "would result in a single-point failure." Where the art itself (Nissan's multi-sensor architecture; Alt's paired same-quantity sensors) supplies multiple sensors for a critical quantity, adding the second like sensor and decoding both is an obvious use of a known technique to improve a known device. MPEP § 2144.04(V).

Weak point / where a patent owner would fight: no single one of the three references, as I can verify it, discloses two separate signal waveforms, each frequency-modulated by one of two redundant position values of the same monitored member, plus a decoder that recovers both positions. That is the specific gap the applicant used to obtain the patent. The rejection therefore lives or dies on (a) the actual disclosure of EP 0 871 011 A2 / JP H1173226 A, and (b) the strength of the "frequency is a known encoding option for vehicle position signals" general-knowledge showing. As constructed here, the combination is substantial but not overwhelming; I would rate the § 103 case on claims 1/2/21/22 as moderate on this record, rising to moderate-to-high if EP 0 871 011 A2 discloses a variable-frequency (or otherwise position-proportional encoded) output, and falling to weak if it discloses only an analog/duty-cycle output with no frequency teaching.

Combination B — Alternative, redundancy-focused: US 4,215,404 (Alt) + the CTS control circuit, with Nissan '785 as the vehicle-context reference

Use this framing if the EP 0 871 011 text proves unhelpful: Alt supplies the frequency-as-information teaching and paired redundant sensors with fault location; CTS supplies the sensor-side circuit that emits an output proportional to input-device position; Nissan supplies the pedal/throttle drive-by-wire context and the exact claimed devices. Motivation: Alt's own stated objective (fault detection and location) plus Nissan's single-point-failure sensitivity supplies the reason to process two position channels through two frequency-modulated waveforms and cross-check them at the controller — the very scheme the '870 Summary announces. This framing is a classic "secondary references for a known technique, primary reference for the environment" combination and is the more defensible structure of the two, though it leans harder on general knowledge for the two-waveform/variable-frequency limitation.

6. Dependent-claim analysis (grouped)

Group 1 — Frequency-ramp relationships: claims 3, 4, 5, 6, 7 and 24, 25, 26, 27

Claims 3–7 set out inverse ramps (one up, one down, with assorted endpoint-frequency relationships: shared endpoints; third frequency between/below; "skewed"; "subset"), and claims 10/11 (and 30/31) the both-up / both-down variants.

Obviousness: these are obvious design choices over any reference teaching a variable-frequency position waveform (Alt + CTS + Nissan), because:

• The patent's own disclosure recites each variant as a mere alternative with no asserted criticality: "Alternatively, the first and second frequency signal conversion modules… may both increase or both decrease"; "The frequency range of the first signal waveform may overlap or be independent of…"; "the first and second signal waveforms… have skewed frequency ranges"; "the frequency range of the second signal waveform may be a subset of the first."
• Choosing between monotonic-increasing, monotonic-decreasing, or overlapping/skewed/nested endpoint frequencies is selection of a result-effective variable by routine optimization with an expected result (MPEP § 2144.04; In re Aller; KSR). Absent evidence of a criticality (unexpected technical effect) attaching to any particular pair of endpoints, the selection is obvious. Note the 250 Hz–5 kHz / 500 Hz–5 kHz / 800 Hz–8 kHz figures — the specification presents them as exemplary ("For example," "may range"), which is a further admission of arbitrary selection. Rating: high confidence of obviousness once a single variable-frequency teaching is established.

Group 2 — Fault-detection and alarm logic: claims 8, 9, 16, 17, 18 and 28, 29, 36, 37, 38

• Claim 8 (compare frequencies; alarm if sum is above/below predetermined bounds): a planned redundancy/plausibility check. With inverse ramps, the sum is (nominally) constant, so a windowed sum test is the mathematically natural implementation — a predictable, unpatentable refinement. Alt '404's express objective is fault detection and location; adding an alarm indicator to a diagnostic is the use of a known technique (alarm/sensor-error indicator) to improve a known system. KSR; MPEP § 2144.04. Rating: moderate-to-high.
• Claim 16 (compare first/second position values; alarm if difference > threshold) and claim 18 (same, on normalized values): this is the textbook redundant-channel rationality/correlation check, conventional safety practice in engine and throttle control and supported by the art on this very page (US 6,317,681 B2 — monitoring operation of IC-engine sensors; US 6,507,198 B1 — detecting faults in measurement quantities of a motor vehicle, subject to date verification). Additionally, the '870 sibling '463 specification describes exactly this check ("determines whether a difference between the position values is greater than a predetermined value") — usable not as art but as corroboration of the artisan's ordinary practice, and it must not be cited as prior art. Rating: high (subject to verifying the two candidate references' dates).
• Claim 17 (normalize position values to a fraction of the min–max travel): obvious design choice; converting a physical displacement to a 0–100 % normalized value is routine and is exactly what the '870 specification itself describes as a matter of implementation preference ("may represent a fraction of the range between an idle throttle position and a wide open throttle (WOT) position… 0 %… may correspond with the idle throttle position"). Rating: high.
• Claims 9 and 29 (resolution mismatch between the two sensors; weighting factor applied to one frequency or position value before comparison): obvious application of a known technique. Weighted combination/weighted averaging of sensors of differing quality is standard; Alt '404 uses amplifiers/averaging across plural sensors, and the use of a weight reflects the relative reliability of the channels — a predictable engineering step. Rating: moderate-to-high.

Group 3 — Signal-format and integrity diagnostics: claims 12, 13, 19, 20, 32, 33, 39, 40

• Claim 12 (square, triangular, trapezoidal, or sinusoidal): enumerated, well-known waveform shapes. Alt '404's signal diagrams and general vehicle/EMC practice supply them; the '870 specification itself explains that the choice is dictated by "radiated emissions standards" and ease of implementation ("while sinusoidal waveforms have the lowest radiated emissions, they are also typically the most difficult to implement") — an express design-tradeoff admission, which makes the selection obvious. Rating: high.
• Claim 13 (detect voltage bias conditions — short-to-battery/short-to-ground): routine automotive input-diagnostic circuitry; the motivation comes directly from Alt's fault-diagnosis purpose and from the general requirement (acknowledged in the '870 text) that a frequency interface must distinguish a stuck or shorted input ("short-to-battery and short-to-ground conditions produce a signal with no frequency"). Adding bias detection to a known interface is a predictable improvement. Rating: moderate.
• Claims 19/20 (frequency filter detecting frequency shifting; low-pass or band-pass): filtering a sensor signal to detect a deviation in its rate is exactly Alt '404's filter 12 / complex-plane-analyzer / averaging-unit architecture, and selecting LPF vs. BPF is a routine choice based on the disturbance spectrum (RC/LC resonance, as the '870 text itself notes). Rating: moderate.

Group 4 — Structural/conductor claims: claims 15 and 35

"First and second conductors… first signal waveform on said first conductor and second signal waveform on said second conductor" — two signals on two wires is the most conventional possible implementation and, notably, is what the '870 Background disparages as the prior approach ("as the number of sensors increases, the number of wires and overall cost increases"). Rating: high. (Separately, note the claim-drafting defect flagged earlier: claim 15 recites "said control module transmits said first signal waveform on said first conductor" although the specification says the sensor module transmits — a § 112(b) vulnerability that can make the claim easier to attack on indefiniteness even before § 103 is reached.)

Group 5 — Method claims 22–41

Mirror the apparatus claims; the same combinations and the same rationales apply. Method claims adding only "transmitting… to a control module" and "determining… at said control module" add nothing beyond the ordinary signal chain of Nissan '785 (sensor → controller → actuator) and Alt '404 (sensor → filter/analyzer → computer).

7. Summary verdict table

Single-reference anticipation (§ 102)? Not on this record. EP 0 871 011 A2 is the closest single reference, but even at title level it does not reach the two-waveform/two-redundant-position-values limitation, and I could not verify its full text — so I make no § 102 assertion. Alt '404 and Nissan '785 each individually miss the variable-frequency-per-position-value limitation.

8. Counterarguments a patent owner would raise (and how strong they are)

1. "No reference teaches two separate variable-frequency waveforms for two redundant measurements of one member." Strongest defense. On this record it is largely correct, and it is the reason the examiner allowed the claims. It forces the rejection to rely on the general-knowledge / finite-option-set bridge (KSR's "obvious to try") and on the AC's own admitted tradeoffs — a bridge KSR permits but that must be articulated with evidence (declaration from a PHOSITA), not merely asserted.
2. "Frequency encoding was not the known solution in pedal-position sensing; the field used analog ratiometric or PWM duty-cycle outputs." Partially supported by the '870 Specifications (which say ASICs output "PWM or other types of signals"). Counter: Alt '404's use of frequency-domain processing in vehicles, plus CTS's sensor-side encoded-output practice, plus the '463 sibling's enumeration of frequency vs. duty cycle as the two alternatives, undermine the "not known" assertion. But this is a fact-intensive contest.
3. "Objective indicia." None found. No litigation, no PTAB/IPR/PGR (consistent with the earlier litigation section), no third-party assignments, no licensing of '870 identified, and no commercial-success/praise evidence in the record. Absence of secondary considerations here favors the obviousness conclusion because there is no counterweight to the art (Graham factor 4 cuts against the patentee). Note, however, that GM's broad deployment of variable-frequency pedal/ETB interfaces in production vehicles could be argued as commercial success if the patentee developed the record — but the required nexus to the claimed invention (as opposed to GM's overall electronic-throttle programs) would be difficult, and the patent is now expired.
4. § 112 companion vulnerabilities (from the earlier claim-anomaly section) — claim 11's antecedent-less "second module" and claim 15's mis-assigned transmitter — do not help the § 103 analysis directly but weaken the claims' ability to be construed narrowly enough to escape the art.

9. Grounding, sources, and explicit uncertainties

Sources actually relied on (with what they establish):

• Google Patents record for US 6,999,870 B2 — citation lists, family, legal events, status: https://patents.google.com/patent/US6999870/en
• US 4,215,404 A (Alt) — Google Patents, disclosure of paired sensors, filter/analyzer/averaging/computer, frequency adjustment unit, pulse-shaper/scaler: https://patents.google.com/patent/US4215404A
• US 5,172,785 A (Nissan) — Google Patents and EveryPatent claim text (accelerator/brake/steering input elements; accelerator position sensor; throttle actuator; transfer function K_D(1+sT_D); plural-sensor claims): https://patents.google.com/patent/US5172785A ; http://www.everypatent.com/comp/pat5172785.html
• EP 0 871 011 A2 — title/abstract level only; family member JP H1173226 A listed on the '870 page. Full text not retrieved; my mapping to this reference is an inference from its title and family, and is flagged as such.
• US 7,126,463 / US 2005/0035870 A1 (sibling of '870, same three provisionals) — used only as evidence of the artisan's ordinary practice and of the enumerated option set; expressly not as § 103 art.

Explicit uncertainties (per the rule to say what I don't know):

• I could not verify the full technical disclosure of EP 0 871 011 A2 in this session; the primary-reference prong of Combination A must be re-grounded on the reference text (and JP H1173226 A) before the rejection is asserted.
• I could not verify the publication dates/assignees of US 6,317,681 B2, US 6,507,198 B1, or WO 2001/071287 A1 beyond the dates shown in the '870 page's listings. Their availability as § 102(b)/(e) art must be confirmed before use.
• No adjudicated claim construction exists for these claims (no litigation, no PTAB — see the earlier litigation section), so the element-mapping above is my own application of the plain claim language as read against the specification, not an adopted construction.
• The date discrepancy between the task header (2026-04-26) and the system/page timestamp (2026-09-27) is noted but immaterial to the § 103 conclusion.

Bottom line. On the art identified on the patent page plus the artisan's ordinary knowledge, claims 1, 2, 21, 22, and 41 are arguably obvious over CTS EP 0 871 011 A2 in view of Nissan '5,172,785 and Alt '4,215,404 (with the frequency-encoding element carried by Alt '404 and general vehicle-electronics knowledge), and the dependent claims — especially the frequency-ramp, normalization, waveform-shape, and redundant-channel-comparison claims — are plainly obvious as design choices and known fault-checking techniques once a single variable-frequency position teaching is established. The single greatest vulnerability of this § 103 theory is the absence, in the references I could fully verify, of an express teaching that two redundant position values are each encoded as the frequency of a separate waveform; that gap is bridgeable only on a KSR "finite predictable solutions / known design incentive" theory supported by competent evidence, including the patent's own admissions about wire count, cost, resolution, and single-point failure.