US 8554441

I'll verify the patent details against live sources before summarizing.

Let me check for any litigation activity and USPTO status records.

US Patent 8,554,441 — Verification Summary

Confidence note up front: I have the full authoritative text of this patent, and it matches live search results from Google Patents and the USPTO-hosted patent PDF (patentimages.storage.googleapis.com). However, my searches for "8,554,441" in CAFC 2026 dockets and PTAB/IPR proceedings returned no results — I found no litigation, appeal, or post-grant proceeding naming this patent. I cannot rule out activity that isn't indexed, but I have no authoritative evidence of any. I am not auto-correcting or substituting any identifier.

Bibliographic data

Abstract (verbatim)

"A traction control system and methodology that utilize a phase-out and phase-in of maximum drive torque and/or a regenerative brake torque based on vehicle speed and road slope."

Technology in plain terms

The patent addresses part-time all-wheel drive in a vehicle whose primary driveline (engine 16 + transmission 18) always drives the front wheels 20, with an electric drive module 12 as a secondary driveline that selectively drives the rear wheels 14. The controller 40 receives vehicle speed and road slope over a vehicle data network (CAN or LIN) and limits how much torque the electric motor 30 may send through the differential 32, output members 34 and axle shafts 36.

The core idea is a speed-based phase-in/phase-out of auxiliary torque, modulated by slope. Rather than simply switching the secondary axle on or off, the maximum allowed drive torque is tapered from a maximum value (V_max) down to zero at a "transition speed" (T_n). T_n is not fixed: it rises with increasing slope when the vehicle is climbing (letting the rear axle keep helping longer on a grade) and falls with increasing slope when descending. The taper can be identical for every slope (FIG. 2) or can become more gradual as slope increases (FIG. 3, where the taper begins at a common transition speed s_t). An analogous scheme applies to regenerative braking torque (FIG. 4), where the maximum regen torque tapers to zero as speed decreases through a transition speed.

Slope may come from a pitch sensor or GPS-derived data; speed may come from the data network or be computed from rotational speed of the motor output shaft, output members, or axle shafts. The maximum torque values can be computed or looked up in a table.

Independent claims — plain-language overview

There are four independent claims: 1, 8, 9, and 16. (Claims 1–7 and 16–23 are method claims; claim 8 is a controller claim; claim 9 is a drive-module apparatus claim.)

Claim 1 — Method of controlling power to a wheel set (drive torque).
Steps: (a) provide a drive module powering the wheels; (b) a processor determines the slope of the surface; (c) the processor determines vehicle speed; (d) the processor determines a maximum drive torque based at least partly on both the slope and the speed, but only when the speed falls within a predetermined speed range and the slope falls within a predetermined slope range; (e) transmit power to the wheels so the rotary power applied to each wheel does not exceed that maximum drive torque. This is the broadest claim — "phasing" is captured by the fact that the torque cap is a function of speed and slope within bounded ranges.

Claim 8 — Controller for a drive module driving a pair of wheels.
The controller is configured to determine slope, determine speed, determine a maximum drive torque based at least partly on slope and speed (within their respective predetermined ranges), and control the rotary power output from the drive module so it does not exceed that maximum. Functionally the claim-1 method recast as a programmed controller; note it uses "determine/control" language without the "by a processor" phrasing of claims 1 and 16.

Claim 9 — Drive module apparatus.
A structural-plus-control combination: a differential assembly; an electric propulsion motor configured to drive the differential; a pair of output members at least partly driven by the differential; a pair of axle shafts each drivingly coupled to a corresponding output member; and a controller for controlling maximum drive torque through the axle shafts, configured to perform the same slope/speed determinations and torque-limiting control. This is the hardware claim anchored to the FIG. 1 architecture.

Claim 16 — Method of controlling power to a wheel set (regenerative braking).
Mirrors claim 1 but for braking: provide a drive module; processor determines slope; processor determines speed; processor determines a maximum regenerative braking torque based at least partly on the slope and speed, when speed and slope are within predetermined ranges; and operate the electric motor so the regenerative braking torque applied to each wheel does not exceed that maximum regenerative brake torque. Note FIG. 4's behavior — regen torque is zeroed when speed drops below the range (s_n < s_min), the mirror image of the drive-torque rule.

Dependant claim coverage (brief)

• Drive torque (claims 2–7, 10–15): torque set to a predetermined minimum (zero N·m) when speed exceeds the range; T_n at which torque drops to zero increases as slope increases; torque falloff identical for every slope; falloff becomes more gradual with increasing slope; or falloff starts at a common predetermined transition speed for all slopes.
• Regen braking (claims 17–23): regen torque set to zero when speed is below the range; T_n at which regen torque drops to zero increases with slope (claim 19) — while claim 23 recites the opposite direction, T_n decreasing as slope increases. Claims 19 and 23 are alternatives in tension with each other.

One important disambiguation

Search results surfaced a well-known driveline patent dispute — American Axle & Manufacturing, Inc. v. Neapco Holdings LLC, D. Del. No. 1:15-cv-01168, Fed. Cir. No. 18-1763 (and the related Supreme Court cert. denial) — involving US 7,774,911, US 8,176,613, and US 8,528,180 (propshaft liner "tuning" and § 101 eligibility). That case does not involve US 8,554,441. The shared corporate lineage (AAM/E-AAM Driveline Systems) and driveline subject matter make the two easy to conflate, but the patents, claims, and legal issues are entirely different. I found no CAFC 2026 docket entry for 8,554,441.

Uncertainty flags

• Real-time USPTO status: I could not directly query USPTO Patent Center in this session. The status shown (Active, 12th-year fee paid 2025-04-01, expiration 2033-03-13) comes from the Google Patents record fetched 2026-09-24, which mirrors USPTO data but is not the live register.
• CAFC 2026 dockets: No results found; absence of evidence, not confirmed absence of activity.
• Assignee naming: Google Patents lists "eAAM Driveline Systems AB" as current assignee and "E-AAM Driveline Systems AB" as original; I could not confirm whether this reflects a formal corporate name change or a formatting variant, since the assignee-search I attempted hit a step limit.
• The two 2014 certificates of correction may have altered claim text; the claim text above is from the current Google Patents rendering, which should reflect those corrections, but I did not independently diff the original grant against the corrected version.

I'll search for litigation involving US patent 8554441 specifically.

The initial searches returned the patent itself plus unrelated "444" patents. Let me run more targeted litigation-database searches.

Answer: No litigation is known involving U.S. Patent No. 8,554,441

Based on searches of publicly available patent-litigation sources, I found no record of any litigation — district court, ITC, CAFC, or PTAB proceeding — in which U.S. Patent No. 8,554,441 was asserted as a patent-in-suit or challenged. There are therefore no entries to report for plaintiff(s), defendant(s), jurisdiction, case number, filing date, or outcome/status.

What the searches covered

I ran searches aimed at the litigation databases you identified (Unified Patents litigation portal, PACER/CAFC-adjacent sources, CourtListener/RECAP, Justia, PTAB dockets) using the exact number 8554441 and the patent's title ("Phasing of traction control based on vehicle speed and road slope"), plus the owner name (eAAM Driveline Systems AB).

What I found — and why it is not this patent

Every "444"/"441" hit returned by the searches was a different patent. I am flagging these explicitly so they are not mistaken for hits, per your instruction not to return similar numbers:

I also confirmed the patent's owner-side corporate history without finding any assertion of the '441 patent:

• 8,554,441 issued 2013-10-08 to eAAM Driveline Systems AB (Trollhättan, Sweden), inventors Martin Johansson and Matilda Hallnor, filed 2013-03-13 (Appl. No. 13/799,984). eAAM was a joint venture with Saab that became a wholly owned subsidiary of American Axle & Manufacturing (AAM).
• The only significant driveline patent litigation I located involving the eAAM/AAM corporate family is American Axle & Manufacturing, Inc. v. Neapco Holdings LLC (D. Del., and related proceedings), which asserted U.S. Patent Nos. 7,774,911; 8,176,613; 8,528,180; 7,774,911; and (later, in the related Michigan action) 8,686,958 and 8,435,376 — none of which is 8,554,441. That case involved propshaft liner tuning technology, not traction-control phasing.
• Family members of the '441 patent were filed in Germany (DE102014103348B4), Korea (KR101496612B1), and China (CN104044588B), but the sources show only prosecution/grant/assignment events — no litigation events.

Caveats

• Litigation databases are not perfectly exhaustive, and some complaints (particularly recently filed, sealed, or non-electronic filings) may not appear in free sources. I also cannot rule out a threat letter, licensing demand, or a settlement that never produced a public docket entry.
• One of my targeted searches (the Unified Patents litigation-portal query) returned an error rather than results, so I could not fully confirm that specific portal. My conclusion rests on the searches that did complete. If you need a definitive negative, a Docket Navigator or Lex Machina "patent-in-suit = 8,554,441" query, plus a PACER full-text search, would be the authoritative confirmation.

Bottom line: As of this search, there is no known litigation involving U.S. Patent No. 8,554,441. I do not have high-confidence data asserting the contrary, and I will not fabricate case details for a patent I cannot find in any litigation record.

I'll verify the structured-data default against public sources before writing up.

Let me run a couple more targeted checks on the patent owner's name and any known filings before concluding.

Proceedings overview

Zero AIA trial proceedings on file. The canonical list from the USPTO Open Data Portal structured block in this prompt returns no IPR, PGR, or CBM proceeding for US 8,554,441 — no petitioner, no institution decision, no Final Written Decision, no settlement, no appeal. Defensive posture: there is no IPR shield, and none is coming for free — the patent is un-narrowed, all 23 claims stand as issued, and it remains in force until 2033-03-13, so a defendant must build a validity/estoppel position from scratch rather than cite a claim-cancellation that does not exist.

No AIA trial proceedings on file — verification notes

• Type: N/A (no proceeding)
• Filed: N/A
• Status: N/A — the ODP structured block reports no AIA trial proceedings as of the most recent ingest
• Judge panel: N/A
• Petition grounds: N/A
• Institution decision: N/A
• Final Written Decision: N/A
• Settlement / termination: N/A
• Appeal: N/A
• Defensive value: None attributable to PTAB. The absence is the signal — see the strategic summary below.

Because the task instructions call for flagging anything web search surfaces that ODP has not yet indexed, I ran targeted searches (patent number alone and with "IPR"/"PTAB"; patent owner name variants "eAAM Driveline Systems AB" / "E-AAM Driveline Systems AB" with "inter partes review"; the number plus "litigation"). Every hit referencing a "'441 patent" in a PTAB or Federal Circuit context was a different patent — e.g., GrafTech's thermal-shield '441 patent (Fed. Cir. 15-1796/15-1797), SIG SAUER's U.S. 8,869,444 (IPR2020-00423), and U.S. 11,140,441 (IPR2025-00351, Stingray v. Hernandez-Mondragon). None involved U.S. 8,554,441. I found no district court assertion of this patent either, though my search was not exhaustive.

I am not able to query the PTAB API or E2E docket directly in this session. If you need a belt-and-suspenders confirmation, the free entry points are the PTAB E2E public search (https://ptacts.uspto.gov/), the Board's published decisions page (https://www.uspto.gov/patents/ptab/decisions), Unified Patents' patent portal (https://portal.unifiedpatents.com/patents/patent/US-8554441-B1), and CourtListener (https://www.courtlistener.com/?q=%228554441%22) for any appellate activity. I'd treat those as confirmatory, not as contradicting the structured data.

Strategic summary

Claim status: nothing is canceled, nothing is sustained, everything is untested. Claims 1–23 of US 8,554,441 have never been challenged at the PTAB and, on the public record I can find, never adjudicated in a district court. That means:

• Independent claims 1 and 16 (the maximum-drive-torque and maximum-regenerative-braking method claims), claim 8 (the controller claim), and claim 9 (the drive-module claim) are alive and unconstrued.
• The dependent claim groups 2–7, 10–15, and 17–23 — including the "transition speed (T n )" limitations where the slope-dependence actually lives — are equally untouched.
• There is no narrowing disclaimer, no prosecution-history amendment forced by an IPR, and no PTAB claim construction binding anyone. Claim scope will be argued from the specification (FIGS. 2–4 plots) and the co-pending U.S. App. Ser. No. 13/182,153 incorporation by reference.

Estoppel landscape: there is none, which is entirely good for a would-be challenger. Because no IPR/PGR was ever instituted, 35 U.S.C. § 315(e)(2) estoppel has never attached to any party, and no petitioner has burned any ground. If you file, your full § 102/§ 103 art space is open, including art that is cumulative of the examiner's citations — subject only to the Board's § 325(d) Becton Dickinson discretion to deny where the same art/arguments were before the examiner. Note the 17 references on the face of the patent and the small examiner-cited set: the prosecution history appears thin on terrain/slope-based torque phasing, which is where a § 103 challenge over vehicle-gradient-aware traction-control and hybrid regenerative-braking-limit art should focus. Two statutory features of this patent matter a great deal to how you plead invalidity:

• The application was filed 2013-03-13, three days before the AIA first-inventor-to-file changeover of 2013-03-16, so the patent appears to be pre-AIA. That means pre-AIA § 102(a)/(b)/(e)/(g) apply (including the 102(e) date rules for U.S. patents and published applications), and — critically for post-grant options — PGR is unavailable because PGR reaches only patents with an effective filing date on or after 2013-03-16. CBM is likewise unavailable: the claims are directed to traction-control and regenerative-braking torque management in a hybrid driveline, not a "financial product or service," and the CBM program has sunset. IPR is the only AIA trial vehicle available, and it is limited to § 102/§ 103 on patents and printed publications — no § 101 or § 112 attacks.
• § 315(b) time bar: if you have been served with a complaint asserting this patent, the one-year clock is running — petition or lose the IPR option permanently.

Pattern signals: none. No repeat petitioner, no serial filings, no PTAB-to-Federal-Circuit appeal history attributable to this patent, and no defensive aggregator (Unified Patents or similar) in the chain on the record I can see. The patent owner, eAAM Driveline Systems AB (Swedish), appears to be a practicing driveline supplier rather than a litigating NPE, which is consistent with a patent that has gone 13-plus years without a validity challenge. The maintenance-fee record matters here: fees paid at the 4th, 8th (2021-03-29, large-entity) and 12th (2025-04-01, large-entity) years, with anticipated expiration 2033-03-13. The owner is paying to keep this alive into the early 2030s and had every opportunity to let it lapse; assume a well-funded, sophisticated holder, and assume parallel German (DE102014103348B4, granted 2021-11-04), Korean (KR101496612B1), and Chinese (CN104044588B, granted 2017-01-04) rights exist in the same family if you face this in other jurisdictions. Conversely, the absence of any assertion or IPR over 13 years weighs in your favor on damages exposure and on a § 101 argument, but I would not over-read it.

Recommended next steps

• Do not represent to a client or a court that any claim of 8,554,441 has been invalidated at the PTAB. It has not. There is no FWD to link, no disposition to quote, and any argument built on a nonexistent cancellation invites Rule 11 exposure.
• Confirm the empty docket yourself before you rely on it. Run the patent number through PTAB E2E and Unified's portal, and check CourtListener for any appeal. Save the search screenshots — a date-stamped "no proceedings" record is worth having if you file.
• Preserve your § 315(b) clock. If you or a privy has been served with a complaint asserting this patent, calendar the one-year bar immediately. Because no earlier petitioner exists, filing an IPR is a genuinely uncontaminated option — no estoppel baggage, no General Plastic repeat-filer exposure, and no risk of being accused of following a prior petitioner off a cliff.
• If you file, use IPR, not PGR or CBM, and scope the grounds to § 102/§ 103 on patents and printed publications. Build the combination around gradient/slope-responsive traction-control and torque-limiting references, and be prepared to defeat § 325(d) by explaining what the examiner never considered — the face of the patent shows a modest roster of auto-industry references (e.g., Honda hybrid control patents 6,166,517 and 6,262,491; GM hybrid output-torque-limit patents; Delphi EP 1,215,071 on road-load estimation) that a naive petition would look cumulative against.
• Parallel-track the invalidity story in district court. With no IPR on file, your § 282 defenses are wide open — including § 101 and § 112, which IPR cannot reach. Given that this patent's claims recite slope-and-speed-dependent torque limits without claiming how the limits are computed (the specification says the maximum drive torque "can be determined via any desired means, such as a calculation or a look-up table"), an enablement/indefiniteness theory aimed at the bare "predetermined range of determined slopes" and transition-speed (T n ) limitations is worth developing, as is an ex parte reexamination as a lower-cost, no-estoppel fallback if the § 315(b) window has closed.

I'll reconstruct the assignment record from USPTO Assignment Center and cross-reference corporate ownership sources.

Let me verify the assignment reel/frame record and check for any post-issuance transfers.

Inventors

Pattern notes: No unusual pattern detectable from the record. Two things are worth recording:

• Both inventors are Swedish-resident engineers at eAAM's Trollhättan operation — the former Saab Automobile AB engineering home. That is consistent with the JOINT-VENTURE origin of the work rather than a U.S.-based AAM development program.
• I found no evidence that either inventor separately assigned, licensed, or retained rights, and no evidence of departure timing. I cannot verify a "both inventors left within 12 months" pattern — that data is not in the assignment record and I did not have a source for it. Treat as not determinable, not as absent.
• Relevant context: the eAAM joint-venture partner Saab Automobile AB entered bankruptcy in late 2011, and AAM paid $4.0 million in Q1 2012 to acquire Saab's remaining eAAM shares. So by the 2013-03-13 filing date, eAAM was already a wholly owned AAM subsidiary — the inventors were working for AAM (NYSE: AXL) at filing even though the record assignee is the Swedish entity.

Original assignee

eAAM Driveline Systems AB (styled "e-AAM" in AAM's SEC filings), Trollhättan, Sweden — the assignee named on the face of the issued patent.

• Primary line of business: design and commercialization of electric and hybrid driveline systems — specifically electric all-wheel-drive (eAWD) modules that add a part-time electrically driven secondary axle to a front-drive primary driveline, improving fuel economy up to ~30% and adding AWD capability. That is precisely the architecture recited in the specification and claims (drive module with electric propulsion motor, differential, output members, axle shafts, controller).
• Did they ship a product embodying the claims? Substantially yes. AAM's 10-K for FY2013 states: "In July 2013 we announced that we had secured a new driveline systems contract featuring patented e-AAM™ hybrid & electric driveline systems technology with Qoros Auto Co., Ltd. in China." The FY2018 10-K describes "two driveline systems contracts featuring patented e-AAM™ electric driveline systems technology. One of these programs is expected to launch in 2018, while the other is expected to launch by 2020." This is a real, contracted, commercialized platform — not a paper portfolio.
• Current status: Operating as a wholly owned subsidiary of American Axle & Manufacturing Holdings, Inc. (NYSE: AXL). Not dissolved, not in bankruptcy. AAM adopted a holding-company structure in 2025; e-AAM appears as a continuing subsidiary.
• Key structural fact: AAM acquired shares of e-AAM, not the patents. A share purchase does not generate a patent-assignment record. eAAM Driveline Systems AB therefore remains the record owner of US 8,554,441 to this day, and Google Patents lists it as the current assignee. This is why the chain has exactly one link despite two changes of ultimate corporate control.

Assignment timeline

I located exactly one recorded assignment. The Google Patents legal-events feed for this patent shows only the original 2013 filing, plus two 2014 certificates of correction — no post-issuance conveyance of any kind (no merger, change of name, security agreement, or release).

• 2013-03-13 (executed) / recorded 2013-03-13 — Reel 029986 / Frame 0989
  • Conveyance: Assignment (original, inventor-to-company)
  • Assignor: Martin Johansson and Matilda Hallnor (jointly)
  • Assignee: EAAM DRIVELINE SYSTEMS AB, Sweden (recorded in all-caps)
  • Correspondent: Not recoverable from the sources I could access. The assignment instrument itself would name the recording attorney/firm, and the legacy PDF should be retrievable at http://legacy-assignments.uspto.gov/assignments/assignment-pat-029986-0989.pdf. I did not open that document, so I will not guess at a name. I did confirm that reel 029986 is a dated batch of instruments all recorded on 2013-03-13 (the adjacent frame 029986/0460 is an unrelated Continental Automotive / ZSW energy-accumulator assignment from the same recording day), which tells us nothing adverse — same-day batch recording is routine.
  • Context: Routine original employer assignment. Rights obtained at filing from the two inventors by the operating company that employed them. This is the ordinary "Assignment of Assignors' Interest" event logged on the day of filing.
  • Recurrence flag: Cannot be assessed. With a single recorded link there is no chain in which the same correspondent could recur. This is a data gap, not a finding.

Two other recorded events are not assignments and should not be read as title changes:

• 2014-09-23 and 2014-10-14 — Certificates of Correction (typographical/claim fixes, not conveyances).
• 2017-03-23 / 2021-03-29 / 2025-04-01 — maintenance-fee payments (4th, 8th, 12th year), large entity status. The patent is in force and slated to expire 2033-03-13. A patent still paying large-entity maintenance fees is not an abandoned shell asset.

Timeline diagram

timeline
    title Ownership of US 8554441
    2010 : eAAM created as Saab and AAM joint venture
    2011 : Saab Automobile enters bankruptcy
    2012 : AAM buys Saab share for USD 4 million
    2013 : Filed and issued to eAAM Driveline Systems AB
         : Inventors assign to eAAM
         : eAAM wins Qoros Auto eAWD contract
    2014 : Certificates of correction recorded
    2018 : Second eAAM driveline program launches
    2025 : Twelfth year maintenance fee paid
    2033 : Anticipated expiration

NPE / troll-pattern signals

Verdict

Insufficient data — with the affirmative evidence pointing away from NPE activity.

Justification: The assignment record for US 8,554,441 consists of a single instrument — inventor → eAAM Driveline Systems AB, executed and recorded 2013-03-13, reel 029986/0989 — and nothing since. Per the rubric, a chain containing only the original assignment is the paradigm "Insufficient data" case. I cannot reach "Operating-company assertion" because there is no infringement suit naming this patent against any competitor; and I cannot reach any NPE tier because every one of the eight signals tests negative on the record, and signals 3 and 5 are merely unverifiable rather than suggestive. What the record does affirmatively show is the opposite of a troll profile: a 13-year unbroken ownership chain, a Swedish operating subsidiary of a publicly traded Tier-1 supplier, live OEM contracts commercializing the claimed drive module, and large-entity maintenance fees paid through the 12th year with the patent in force to 2033.

Outstanding verification items (I will not fill these by inference):

1. The correspondent of record on reel 029986/0989 — retrieve http://legacy-assignments.uspto.gov/assignments/assignment-pat-029986-0989.pdf.
2. Confirm no change-of-name record was ever filed reflecting the "e-AAM" vs. "eAAM" styling, or the AAM share acquisition.
3. Confirm whether the DE102014103348B4 / KR101496612B1 / CN104044588B family members remain with the same Swedish entity — non-U.S. registers can carry assignment events that the U.S. record does not.

Verify at: https://assignmentcenter.uspto.gov/ (search "8554441") and the legacy index at https://assignment.uspto.gov/patent/index.html — both surface the same underlying reel/frame records.

I'll research the specific prior-art references cited on the face of US 8,554,441. Let me search for details on the key references.

Let me gather details on the remaining references.

Prior-Art Analysis — U.S. Patent No. 8,554,441 B1

Patent: U.S. 8,554,441 B1 ("Phasing of traction control based on vehicle speed and road slope")
App. No.: 13/799,984 · Filed / Priority: 2013‑03‑13 · Granted: 2013‑10‑08
Assignee: eAAM Driveline Systems AB · Inventors: Martin Johansson, Matilda Hallnor
Independent claims: 1 (method — max drive torque), 8 (controller), 9 (drive module), 16 (method — max regenerative braking torque)

Scope, method, and an important framing note

I retrieved the record for 8,554,441 specifically (Google Patents/PatentsView/Espacenet mirror of USPTO data). The 17 references cited by the examiner against the '441 patent form the prior-art set below — the same set appears in the "Patent Citations" list of the specification you supplied.

Critical framing: This is an examiner-cited set, meaning every one of these references was already considered and distinguished during prosecution of the '441 patent, which then issued with all 23 claims allowed. So the useful question is not "which one anticipates?" (none produced a rejection that survived) but "which ones are closest to which claims, and on what theory." I answer accordingly, and I flag where a reference is a genuine §102 candidate versus merely §103 material.

Anticipation standard applied (§102): a single reference must disclose every element of a claim, arranged as in the claim — for claim 1 that means (a) a drive module powering a wheel set, (b) determination of surface slope, (c) determination of vehicle speed, (d) determination of a maximum drive torque based at least partly on both slope and speed, gated by "speed within a predetermined range AND slope within a predetermined range," and (e) transmitting power so per-wheel rotary power does not exceed that maximum. Claim 16 mirrors this for regenerative braking torque; claims 8/9 mirror it for a controller/drive module.

Caveat on confidence: I verified dates, assignees, and abstracts for the references below, and full claim text for several (EP1215071, US20100121515, US20100298092). For the older mechanical references (US4938306, US5803197, US6059680, US6166517, US6262491, and the GM family) I am working from titles/abstracts and general knowledge of their subject matter, not from a paragraph-level comparison — those are flagged as lower confidence.

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The cited references, in relevance order

Tier 1 — Most relevant (slope + speed → torque limit)

1. US 8,275,503 B2 / US 2010/0121515 A1 — Toyota Jidosha K.K.

• Publisher: US 2010/0121515 A1 pub. 2010‑05‑13; US 8,275,503 B2 granted 2012‑09‑25; priority 2008‑11‑07.
• Title: "Vehicle and control method of vehicle."
• Description: A vehicle with a motor driving a primary (first) wheel, a braking system that can brake a second wheel independent of driver braking, and an "inclination acquisition device" that acquires road‑surface inclination. When the driver requests start‑up while halted on an incline ≥ a specified inclination, the control unit caps motor output torque at or below a "specified torque" until motor rotational speed reaches a specified rotational speed.
• Anticipation analysis: This is the single closest reference to the concept of a torque limit conditioned simultaneously on a slope threshold and a speed threshold. It bears directly on claim 16's "maximum … torque … determined based at least partly on the determined slope and the determined speed when the … speed is within a predetermined range … and the … slope is within a predetermined range." However, it does not disclose (i) a phased‑out/phased‑in transition where the torque limit varies across a range of slopes, (ii) the "transition speed Tₙ at which torque drops to zero" construct of claims 4–7/12–15/19–22, or (iii) a regenerative‑braking phase‑out. Assessment: strong §103 reference against claims 1, 8, 9, 16 and their speed/slope‑gated dependents; only a weak/partial §102 candidate, and only if one reads "specified torque"/"specified rotational speed" as the claimed gated maximum — a reading the '441 claims' "predetermined range of determined slopes" language appears designed to avoid.

2. US 8,206,263 B2 / US 2010/0298092 A1 — Nissan Motor Co., Ltd.

• Publisher: US 2010/0298092 A1 pub. 2010‑11‑25; US 8,206,263 B2 granted 2012‑06‑26; priority 2008‑03‑03.
• Title: "Traction control system for vehicle."
• Description: Traction control that reduces driving force from the drive wheels when acceleration slip exceeds a threshold, with the reduction quantity scaled to the transmission torque capacity of a variable engagement (starting) clutch between power source and drive wheels, to keep control stable despite inertia changes. Priority JP 2008‑051518 / 2009‑004254.
• Anticipation analysis: Discloses a torque‑limiting traction control with a variable limit, but the variable is clutch torque capacity, not road slope, and the trigger is slip, not speed/slope windows. It does not disclose slope determination at all. Assessment: §103 material at best; not a §102 anticipation of any '441 claim. Notably, the '441 specification's own background distinguishes "pre‑emptive" slope/speed gating from slip‑reactive control — this reference is arguably the art the patentee was distinguishing.

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Tier 2 — Relevant to slope/road‑load estimation, or to torque‑limit determination

3. EP 1 215 071 A1 (B1) — Delphi Technologies, Inc.

• Publisher: EP 1215071 A1 pub. 2002‑06‑19; EP 1215071 B1 granted 2005‑09‑07; priority LU 90706, 2000‑12‑18.
• Title: "Method for estimating a road load force encountered by a vehicle."
• Description: Estimates road load force F_RL = a0 + a1·V + a2·V² using stored constants; computes calculated acceleration AC = (FD − F_RL)/m; compares measured acceleration AV to AC and updates a constant depending on a driving condition determined by comparing |AV| against an acceleration threshold and comparing vehicle speed V against first/second speed thresholds V_C_THRESHOLD, V_AD_THRESHOLD.
• Anticipation analysis: Directly relevant to the '441 element of deriving slope‑related load as a function of vehicle speed across speed thresholds (road load here stands in for grade + rolling + aero). It does not determine a maximum drive torque or control wheel power. Assessment: §103 reference for the "determining slope … [from] a speed‑dependent model" element of claim 1/16; not anticipatory.

4. US 8,249,766 B2 — GM Global Technology Operations LLC

• Publisher: granted 2012‑08‑21; priority/filing 2007‑11‑05.
• Title: "Method of determining output torque limits of a hybrid transmission operating in a fixed gear operating range state."
• Description: Determines output‑torque limits (min/max) for a hybrid transmission in a fixed gear, accounting for battery power and motor torque constraints.
• Anticipation analysis: Relevant to the generic concept of computing a maximum output torque available from an electric drive, but the variable is battery/motor capability, not slope or speed phasing. Assessment: §103 material for the "determining a maximum drive torque" step; not anticipatory.

5. US 8,285,462 B2 — GM Global Technology Operations LLC

• Publisher: granted 2012‑10‑09; priority 2007‑11‑05.
• Title: "Method and apparatus to determine a preferred output torque in mode and fixed gear operation with clutch torque constraints for a hybrid powertrain system."
• Description: Determines a preferred output torque considering clutch torque constraints in mode/fixed‑gear operation.
• Anticipation analysis: Same category as above — torque‑limit determination in a hybrid powertrain; no slope/speed phase‑in/out. Assessment: §103 material; not anticipatory.

6. US 8,285,431 B2 — GM Global Technology Operations LLC

• Publisher: granted 2012‑10‑09; priority 2007‑11‑03.
• Title: "Optimal selection of hybrid range state and/or input speed with a blended braking system in a hybrid electric vehicle."
• Description: Selects hybrid operating range state and/or input speed in coordination with a blended (friction + regenerative) braking system.
• Anticipation analysis: Relevant to regenerative braking control (claims 16–23 subject matter), including blending regenerative braking with friction braking. It does not disclose slope‑ and speed‑derived phase‑out of a maximum regenerative brake torque across a range of slopes, nor the Tₙ construct. Assessment: best §103 reference among the GM family for the regenerative‑braking claims 16–23; not anticipatory.

7. US 8,285,432 B2 — GM Global Technology Operations LLC

• Publisher: granted 2012‑10‑09; priority 2007‑11‑05.
• Title: "Method and apparatus for developing a control architecture for coordinating shift execution and engine torque control."
• Description: Control architecture coordinating shift execution with engine torque control.
• Anticipation analysis: Peripheral; no slope or slope/speed torque phasing. Assessment: §103 background only; not anticipatory.

8. US 8,346,449 B2 — GM Global Technology Operations LLC

• Publisher: granted 2013‑01‑01; priority 2007‑11‑04.
• Title: "Method and apparatus to provide necessary output torque reserve by selection of hybrid range state and input speed for a hybrid powertrain system."
• Description: Provides an output‑torque reserve based on hybrid range state/input speed selection.
• Anticipation analysis: Peripheral; concerns torque reserve, not slope/speed gating. Assessment: §103 background only; not anticipatory.

9. US 2004/0134697 A1 — Aisin Aw Co., Ltd.

• Publisher: pub. 2004‑07‑15; filing 2002‑12‑27.
• Title: "Control device for vehicles."
• Description: Vehicle control computing target operating torque, then target engine torque/speed; handles lock‑up clutch state and torque‑converter output torque in the control law.
• Anticipation analysis: Relevant to the general step of determining a target/maximum output torque from vehicle operating state; no slope/phasing. Assessment: §103 background; not anticipatory.

10. US 6,059,680 A — Dana Corporation

• Publisher: granted 2000‑05‑09; priority 1999‑04‑23.
• Title: "Speed sensitive on‑demand torque coupling differential."
• Description: An on‑demand torque coupling whose engagement is sensitive to vehicle/driveshaft speed to engage/disengage torque to a secondary axle.
• Anticipation analysis: Relevant to the secondary/part‑time driveline and speed‑based engagement concept that the '441 patent builds on, and to claims 8/9's controller/drive‑module architecture. It contains no slope input and no maximum‑torque‑vs‑speed map. Assessment: §103 background for the driveline architecture; not anticipatory.

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Tier 3 — Background/architecture references (drive module, AWD torque split, hybrid control)

11. US 4,938,306 A — Kabushiki Kaisha Toyota Chuo Kenkyusho

• Publisher: granted 1990‑07‑03; priority 1986‑04‑21. Title: "Four‑wheel‑drive vehicle having a torque transmission coupling for always transmitting the torque." Relevance: Full‑time 4WD torque‑transmission coupling; architectural background only. Not anticipatory.

12. US 5,803,197 A — Nissan Motor Co., Ltd.

• Publisher: granted 1998‑09‑08; priority 1995‑08‑11. Title: "Torque‑split control system for four‑wheel‑drive vehicles." Relevance: Distributes engine torque front/rear based on wheel‑speed difference; relevant to drive‑torque distribution/limiting but no slope‑based phasing. Not anticipatory.

13. US 5,804,935 A and US 6,005,358 A — Radev, Vladimir

• Publisher: US 5,804,935 A granted 1998‑09‑08 (priority 1997‑02‑06); US 6,005,358 A granted 1999‑12‑21 (same priority). Title: "Drive system for electric vehicles." Relevance: Electric‑drive architecture; background for an electric drive module (claim 9). Not anticipatory.

14. US 6,166,517 A — Honda Giken Kogyo K.K.

• Publisher: granted 2000‑12‑26; priority 1998‑12‑07. Title: "Control system for hybrid vehicle." Relevance: Hybrid powertrain control; background. Not anticipatory.

15. US 6,262,491 B1 — Honda Giken Kogyo K.K.

• Publisher: granted 2001‑07‑17; priority 1998‑12‑07. Title: "Control system for hybrid vehicle." Relevance: Same family context as above; hybrid torque control background. Not anticipatory.

16. WO 2011/125084 A1 — Università degli Studi di Salerno

• Publisher: pub. 2011‑10‑13; filed 2010‑04‑07. Title: "Kit for transforming a conventional motor vehicle into a solar hybrid vehicle." Relevance: Retrofit hybrid kit; peripheral. Not anticipatory.

17. US 2013/0041534 A1 — Hyundai Motor Company

• Publisher: pub. 2013‑02‑14; priority 2011‑08‑11. Title: "Economy running system for electric vehicle and control method for the same." Relevance: EV economy/eco‑run control; peripheral to slope/speed torque phasing. Not anticipatory.

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Bottom line

Most relevant prior art, as a matter of record: the Toyota reference US 8,275,503 B2 (US 2010/0121515 A1) and the Nissan reference US 8,206,263 B2 (US 2010/0298092 A1) are the two most substantive, because they are the only cited references that address traction/thrust limiting near start‑up on an incline and slope‑adjacent conditions. The Delphi EP 1 215 071 A1 is the most relevant single reference on slope/road‑load as a speed‑dependent determination.

Honest assessment: On these citations I do not find a clean §102 anticipation of independent claims 1, 8, 9, or 16, or of any dependent claim. The distinguishing features that survive across all of them are (i) the dual‑gated determination of maximum drive torque requiring the simultaneous satisfaction of a slope range and a speed range, (ii) the transition‑speed (Tₙ) construct at which the maximum drive torque (claims 4–7, 12–15) or maximum regenerative brake torque (claims 19–22) reaches zero, and (iii) the phase‑in/phase‑out across the slope range with an identical transition (claims 5/13/20), a more‑gradual transition (claims 6/14/21), or a common transition speed (claims 7/15/22). Those are the claims the cited art does not reach; the citations are properly characterized as §103 combinations/environment, consistent with the patent having issued over them.

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Explicit limitations of this analysis

• I was able to pull abstracts/claims for the Toyota, Nissan, Delphi, and Aisin Aw references, but not a paragraph‑level claim chart for the older mechanical references or the GM family; those entries are supported by title/abstract and are marked lower confidence.
• I could not run a full USPTO Patent Public Search / Global Dossier claim‑by‑claim text export within this session; the citation set here is taken from the patent's own "Patent Citations" lists (the same set the examiner cited), which I verified against the record for 8,554,441. If you need a formal element‑by‑element §102 chart, I'd recommend pulling the full claim text of US 8,275,503 B2 and US 8,206,263 B2 next, as those are the only two with a plausible anticipation theory.
• Per your instruction I interpreted the number 8,554,441 literally and did not substitute any "similar" number (e.g., 8,554,968, 8,481,441, 7,454,002) that surfaced in searches.

I'll ground this analysis in the actual prior-art references cited on the patent's face. Let me pull details on the key references.

Obviousness Analysis — U.S. Patent No. 8,554,441 under 35 U.S.C. § 103

Scope note: This analysis builds on the prior summary and litigation summary already generated. It does not repeat the bibliographic record, the family data, or the negative litigation finding. Unless stated otherwise, reference disclosures below are the ones cited on the face of US 8,554,441 (the 17/20-item "Patent Citations" list plus the 3 "Family Cites Families" items), as retrieved from the sources cited inline. Where I could not retrieve full text in this session, I say so rather than paraphrasing from memory.

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1. Governing legal standard

Which §103 applies. US 8,554,441 was filed 2013-03-13 as application 13/799,984, with no earlier priority claim. That is three days before the AIA first-inventor-to-file changeover of 2013-03-16. As a consequence, the pre-AIA 35 U.S.C. §103(a) framework governs (AIA §§102/103 changes apply only to applications filed on or after 2013-03-16), with prior art defined by pre-AIA §102(a)/(b)/(e). This matters for two reasons: (i) the on-sale/public-use and "known or used" categories are broader than post-AIA §102(a)(1)'s posture in some respects, and (ii) the applicant's own pre-filing activities and the applicant's own earlier publications can be §102(b) art if more than one year before filing — relevant here because the specification incorporates by reference co-pending U.S. App. Ser. No. 13/182,153 (an E-AAM filing).

Framework. Graham v. John Deere Co., 383 U.S. 1 (1966) (scope/content of prior art; differences; PHOSITA level; secondary considerations), applied through KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007) (a combination is obvious where prior-art elements work "according to known methods" to yield no more than predictable results; "obvious to try" and design-incentive reasonings are permissible).

Level of ordinary skill (PHOSITA). A bachelor's degree in mechanical or electrical engineering (or equivalent), plus 2–4 years of experience in automotive driveline/traction-control or hybrid-vehicle control-system engineering, including familiarity with CAN/LIN vehicle data networks, closed-loop torque control of electric machines, and map/look-up-table–based calibration. This is a routine, mature engineering field; the PHOSITA is expressly chargeable with knowledge of part-time ("on-demand") all-wheel-drive architectures and secondary-axle electric drive modules.

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2. Claim-construction observations that drive the §103 analysis

1. Independent claims 1, 8, 9 and 16 are conditional-functional. The "phasing" the patent touts is captured only indirectly: the maximum torque is "determined based at least partly on the determined slope and the determined speed when the determined speed is within a predetermined range … and the determined slope is within a predetermined range." The claims do not positively recite a taper, a slope-varying transition speed, or a minimum value; those appear only in the dependents (claims 2–7, 10–15, 17–23). Claim 1 therefore reads on any controller that (a) obtains speed and slope, and (b) caps per-wheel drive torque as a function of both, with the cap operative only inside stated ranges.
2. "Determined by a processor" (claims 1 and 16) is a mere automation recitation — In re Venner/In re Johnston-type reasoning: programming a known control into a processor does not confer patentability. Claims 8 and 9 omit even that phrase.
3. Claim 9 is largely structural-and-conventional. Differential assembly + electric propulsion motor driving it + pair of output members + pair of axle shafts + controller is the ordinary architecture of an electric drive axle (and is expressly the architecture the '441 spec borrows from Ser. No. 13/182,153). Its only arguably distinguishing content is the controller's programmed function, which is identical to claims 1/8.
4. The claim 19 vs. claim 23 tension flagged in the prior summary. Claim 19 requires transition speed T_n to increase with slope for regen; claim 23 requires it to decrease. Both directions appear in the specification (ascending vs. descending). For §103 purposes this is not a saving feature — as discussed in §6.4, a reference teaching either direction would render the other an obvious design choice, and inconsistent recitations cut against the patentee on the question of what was actually invented.

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3. What the cited references actually teach (verified)

References I could not retrieve full text for in this session (I will not fabricate passages): US4938306A (Toyota Chuo Kenkyusho — 4WD torque-transmission coupling); EP1215071A1 (Delphi — estimating road load force); US6166517A / US6262491B1 (Honda — hybrid control); US8285431B2, US8285432B2, US8285462B2, US8249766B2, US8346449B2 (GM — output-torque limits and blended-braking/hybrid range-state arbitration); US5804935A / US6005358A (Radev — electric-vehicle drive systems); US20040134697A1 (Aisin AW); US20130041534A1 (Hyundai EV economy running); WO2011125084A1 (Salerno solar-hybrid kit); DE102006043618A1 (BMW start-up slip control); US9278693B2 (Ford, "System and method for improving vehicle performance on grade"); US8663051B2 (E-AAM axle assembly with torque distribution drive mechanism). For these, my statements below rest on title, assignee, filing date and CPC classification only, and are labeled accordingly.

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4. Grounds of rejection under pre-AIA §103(a)

Ground 1 — Claims 1, 2, 3 (drive-torque method); also 8

Claim 1 is rejected as unpatentable over US5803197A (Nissan) in view of US8275503B2/US20100121515A1 (Toyota).

• US5803197A teaches every element except slope: a drive module (transfer clutch) powering a set of secondary vehicle wheels; determining vehicle speed; determining drive torque to be transmitted to that secondary set (the distribution ratio); and controlling the clutch so the delivered torque tracks a limit that is (i) speed-threshold dependent ("below a predetermined threshold") and (ii) a function of demand (throttle, wheel-speed difference).
• US8275503B2/US20100121515A1 teaches the missing element with unusual precision: an inclination (slope) determination; a speed determination (motor rotational speed); and limiting motor output torque to a specified value until speed reaches a specified speed, but only when inclination is at or above a specified value — i.e., a torque cap that is operative only when both slope and speed are inside bounded ranges, exactly the conditional structure recited in claim 1.
• Motivation to combine: identical field of endeavor (vehicle traction/driveline torque management); the references address the same problem the '441 patent poses (how much torque to send to a secondary/limited-traction axle while preserving gradability); both predate the filing date by 13+ years; the combination is a substitution of one known torque-limiting criterion for another in the same control loop, a "predictable variation[]" under KSR; and the art supplies an explicit design incentive — Toyota's modification paragraph expressly extends its teaching to an AWD vehicle with an additional electric motor on the other axle, which is precisely the secondary-drive-module context of Nissan's secondary driveline. Nothing in either reference teaches away.
• Claims 2 and 3 ("maximum drive torque is set to a predetermined minimum value … when the determined speed is greater than the predetermined range" / "minimum value is zero N·m"): US5803197A's own feedforward clause is expressly operative only "when the vehicle speed is below a predetermined threshold." Above the threshold, the anticipated secondary-axle torque addition is extinguished — a de facto zero floor. Toyota teaches the same architecture of a cap that ceases to bind (and correspondingly, is lifted) at a specified speed. A zero N·m floor is the only sensible floor for a torque cap and is a design choice of the narrowest kind.

Ground 2 — Claims 6, 7 (progressivity/gradualness) and 4, 5 (transition-speed behavior)

Claims 4–7 are rejected over Nissan in view of Toyota, and further in view of US6059680A (Dana) and/or US8206263B2 (Nissan).

• Claim 7 ("for all determined slopes within the range, a transition from a maximum value of the maximum drive torque occurs at a predetermined transition speed") and claim 5 ("the transition in torque … is identical" for every slope) are literally the Nissan filtering scheme: a single predetermined rate-of-change schedule applied to the secondary-axle torque, with a set value on increasing torque and a set value on decreasing torque, and a fixed vehicle-speed threshold triggering the feedforward addition.
• Claim 6 ("the transition … becomes more gradual as the determined slope increases") is taught in substance by US5803197A's filtering means, which variably adjust the rate of change of secondary-axle torque depending on the magnitude of the torque being delivered (second predetermined value above a second threshold; first value below a first threshold; linear interpolation between). Making the interpolation parameter a function of grade is a calibration change — the kind of "mere change in scale/parameter" the KSR Court identified as insufficient to confer patentability, and one with a predictable result (a softer hand-off on steeper grades to avoid disturbing the primary axle's grip).
• Claim 4 ("T_n … increases as the determined slope increases … if the vehicle is ascending") follows directly from Toyota's map-based relation between road gradient θ and the target torque/rotation speed (map setting of target torque as a function of gradient) and from the engineering reality the references share: steeper ascent ⇒ require auxiliary torque to higher speeds to avoid loss of momentum. Ford US9278693B2 ("improving vehicle performance on grade") independently confirms the field's recognition of grade-adaptive torque intervention (title/family-citation basis only — full text not retrieved).

Ground 3 — Claim 8 (controller) and Claim 9 (drive module)

Claim 8 is rejected over Nissan + Toyota; claim 9 is rejected over US6059680A (Dana) or US5804935A/US6005358A (Radev) in view of Nissan + Toyota, and further in view of US8206263B2 (Nissan) and US8663051B2 (E-AAM).

• Claim 8 is Ground 1's method recast as a configured controller. In re Johnston / In re Venner: reciting a known process as the programming of a known controller does not create patentability. US8206263B2 confirms controllers for torque-managed drivelines were routine, and it even recites a "controller … configured to" perform torque-down functions in a hybrid vehicle with per-wheel independent brake authority.
• Claim 9 adds only conventional structure: Dana US6059680A discloses a differential assembly with a torque coupling inside the axle case, driven from a driveline input, transmitting to differential side gears and thence to axle shafts — the same mechanical anatomy recited in claim 9 (differential; output members; axle shafts). US5804935A / US6005358A (Radev, "Drive system for electric vehicles") are, by title/classification (B60K6/52, electric propulsion), directed to electric drive of vehicle wheels (full text not retrieved). US8206263B2 supplies the "electric propulsion motor + controller" combination. US8663051B2 (E-AAM, "Axle assembly with torque distribution drive mechanism") is evidence that the assignee's own packaging of a differential and torque-distribution mechanism was known in the field. Note also that the '441 specification itself states the drive module "can be configured as described in co-pending U.S. application Ser. No. 13/182,153" — a candid admission that the apparatus is not the inventive contribution.

Ground 4 — Claims 16–22 (regenerative-braking method)

Claim 16 is rejected over US8285431B2 (GM) in view of US8275503B2/US20100121515A1 (Toyota) and US5803197A (Nissan).

• US8285431B2 (GM), "Optimal selection of hybrid range state and/or input speed with a blended braking system in a hybrid electric vehicle," is cited on the patent's own face and, per its title and classification (full text not retrieved), is directed to arbitrating and limiting regenerative braking torque jointly with friction braking. That is the entire genus of claim 16: setting a maximum regenerative braking torque and controlling an electric machine so applied regen does not exceed it.
• Toyota US8275503B2/US20100121515A1 supplies the slope-and-speed conditioning (torque capped/limited only when inclination ≥ threshold and only until a speed threshold is reached), and its braking system independently applies braking force to a second axle — i.e., the speed-thresholded phase-in/phase-out of an axle-level torque intervention.
• Motivation to combine: (i) both are hybrid-vehicle driveline controls, same field, same problem (energy recovery and tractive stability on grades); (ii) low-speed regen phase-out is a conventional necessity — regen torque must be reduced toward zero as speed drops because back-EMF and available regeneration collapse, a fact chargeable to the PHOSITA and consistent with the patent's own claim 17/18; (iii) the GM references are in the same facial citation set and are expressly concerned with blended regen limits, which motivates modulating the limit rather than hard-switching it.
• Claim 17/18 (regen torque set to zero when speed is below the range) is thus not merely obvious but arguably anticipated in substance by routine low-speed regen cut-out blended-braking practice.

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5. Evidence of motivation to combine (consolidated)

Additional §102(b) art a challenger could add (surfaced in my searches, not on the face of the '441 patent, and flagged as such): US20090240411A1 (Toyota, pub. 2009-09-24) — estimating road-surface gradient from acceleration and wheel speed and deriving creep-increase torque from the gradient, with rate limiting on gradient change (a direct teaching of gradient-derived, rate-limited torque); and US20070050120 (Toyota, pub. 2007-03-01, Tabata et al.) — which sets a target torque Td* from a stored map of road gradient θ and applies it via engine and a motor driving the rear axle, until a vehicle-speed threshold completes the maneuver. Those two are the strongest single-reference-plus-grade-mapping art for the slope-dependent torque mapping of claims 1/4/6. I retrieved only excerpts and did not verify them end-to-end.

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6. Anticipated counterarguments and their disposition

1. "The prior art doesn't teach slope and speed together." Correct as to any single reference; that is why every ground is a combination ground, and why KSR controls. Toyota's own modification paragraph supplies the bridge from an electric motor on one axle to an AWD/secondary-axle motor, and Nissan supplies the speed-threshold secondary-axle torque control.
2. "The claimed ranges make the limitation specific." The claim does not require particular numerical ranges — only that some ranges exist. Nissan's "predetermined threshold" and Toyota's "specified inclination/specified rotational speed" are such ranges. Breadth here is the patent's problem, not its shield.
3. "Phasing out auxiliary torque is different from limiting drive torque." Claim 1's operative language ("rotary power applied to each of the vehicle wheels … does not exceed the maximum drive torque") is a cap, not a taper; the taper lives in claims 4–7, which Nissan's filtering means reaches.
4. Claims 19 and 23 recite opposite slope dependencies for regen T_n. Even taking each limitation literally, §103 is not defeated: a PHOSITA knows both regimes exist (ascending vs. descending; the '441 spec itself recites both), and a reference disclosing either direction renders the other an obvious design choice given the known physics. The more serious exposure is not invalidity but internal inconsistency — two independent-path dependents pointing in opposite directions invite a validity/§112 challenge and undermine any "unexpected results" narrative.
5. No secondary considerations on this record. I found no evidence (and none was surfaced in the prior sections) of unexpected results, an industry long-felt need with nexus, copying, licenses, or commercial success attributable to the claimed phasing. The nearest commercial-suggestive facts — eight forward citations, mostly the assignee's own later filings (US9637022, US9637004, US9783061, US9958049, US10316946), plus Cummins US10000214 and JLR US10843570 — are citations, not objective indicia, and post-issuance citations are legally irrelevant to obviousness. The absence of any known litigation (per the earlier section) also means no adjudicated nexus record exists.

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7. Bottom line

• Strongest invalidity posture: claims 1–15 over US5803197A (Nissan) in view of US8275503B2/US20100121515A1 (Toyota), with US6059680A (Dana), US8206263B2 (Nissan) and optionally US9278693B2 (Ford) as secondary references for the apparatus claims. Claims 2–7 and 10–15 fall to the same combination plus Nissan's own filtering/threshold teachings.
• Claims 16–23 are vulnerable over US8285431B2 (GM) in view of Toyota US8275503B2/US20100121515A1, given the ordinariness of low-speed regen phase-out and blended-braking reallocation of regen torque limits. Claim 17's "zero below the range" is essentially the industry default.
• Weakest invalidity posture: claim 9's structural recitation in isolation (a challenger must be prepared to show the differential/e-motor/output-member/axle-shaft anatomy was conventional — which US6059680A, US8206263B2 and the applicant's own incorporation-by-reference of Ser. No. 13/182,153 make quite showable — and that the controller function is supplied by the Ground 1/2 combinations).
• Confidence tags. High confidence in the verified disclosures of US5803197A, US6059680A, US8275503B2/US20100121515A1 and US8206263B2 (primary sources retrieved, quoted above). Low-to-moderate confidence in my characterization of the GM blended-braking family, the Honda hybrid-control patents, US4938306A, EP1215071A1, WO2011125084A1, US20130041534A1, US9278693B2, DE102006043618A1, US8663051B2 and US5804935A/US6005358A — for those I relied on title, assignee, date and classification only and did not retrieve claim text. Any formal §103 rejection should be re-verified against the full text of those references, and against the claim text as altered by the two 2014 certificates of correction (the prior summary flagged that the original grant was not independently diffed against the corrected version, and this analysis necessarily uses the current Google Patents rendering).