US 8315769

A technical analysis of U.S. Patent 8,315,769 is provided below.

Summary of U.S. Patent 8,315,769

Title	Absolute acceleration sensor for use within moving vehicles
Assignee	Vision Works IP Corp
Inventors	Alfred S. Braunberger, Beau M. Braunberger
Filing Date	November 22, 2011
Issue Date	November 20, 2012
Abstract	A communication system for a vehicle includes a vehicle speed sensor configured to emit a periodic function with a parameter correlated to the speed of the vehicle, an acceleration monitoring system, a braking system engagement detector to detect a braking status of the vehicle, an alerting device capable of signaling other drivers of a deceleration condition of the vehicle, and a control device. The acceleration monitoring system is configured to compute the acceleration of the vehicle from variations in the parameter of the periodic function of the vehicle speed sensor and to output a deceleration status of the vehicle. The control device is coupled to the acceleration monitoring system, the braking system engagement detector, and the alerting device, wherein the acceleration monitoring system sends signals to the control device and the control device operates the alerting device in a manner dependent on the deceleration status of the vehicle.

Plain-Language Overview of Independent Claims

This patent contains three independent claims which define the core inventions.

• Independent Claim 1: This claim describes a device for a vehicle that uses a combination of an accelerometer and a gyroscope to accurately measure the absolute side-to-side (lateral) acceleration, independent of the vehicle's tilt or orientation. The device uses this measurement to signal a "suspension selector" which in turn directs multiple controllers to individually adjust different parts of the vehicle's suspension system. The core idea is a device that senses true lateral force to actively manage the suspension.

• Independent Claim 9: This claim outlines a broader system for controlling vehicle performance. It includes the accelerometer-gyroscope for sensing absolute lateral acceleration, a suspension selector that receives signals from this sensor, multiple controllers that receive signals from the selector, and one or more suspension systems that are individually activated by the controllers. This creates a complete feedback loop from sensing lateral motion to adjusting the vehicle's suspension to improve performance characteristics, such as preventing rollovers.

• Independent Claim 21: This claim describes a method, or a series of steps, for controlling a vehicle's performance. The method consists of:

  1. Sensing the lateral acceleration of the vehicle.
  2. Sending a signal based on this sensed acceleration to multiple control devices.
  3. Adjusting a characteristic of the vehicle's suspension in response to the signal.
     This claim protects the process of actively controlling the suspension based on lateral acceleration measurements.

Litigation Search

A search of the CAFC (United States Court of Appeals for the Federal Circuit) 2026 dockets for patent number 8,315,769 did not yield any specific results. I do not have authoritative information to report regarding litigation for this patent in the specified court and timeframe.

Litigation History of U.S. Patent 8,315,769

Contrary to the previously generated summary, which found no litigation, U.S. Patent 8,315,769 has been asserted in numerous legal disputes. The plaintiff in all identified cases is Vision Works IP Corp. The patent is frequently litigated alongside other patents in the assignee's portfolio.

Details of the known litigation are as follows:

Case Number	Jurisdiction	Defendant(s)	Filing Date	Status/Outcome
2:25-cv-00999	Texas Eastern District Court	Tesla, Inc.	2025-10-01	Dismissed without prejudice on 2026-01-29.
2:25-cv-00429	Texas Eastern District Court	Suzuki Motor Corp.	2025-04-23	Open/Ongoing. This is the lead consolidated case.
2:24-cv-01013	Texas Eastern District Court	Jaguar Land Rover Automotive PLC	2024-12-09	Ongoing as of early 2025.
2:24-cv-02021	New Jersey District Court	Volvo Car USA LLC	2024-03-08	Closed.
1:24-cv-00961	Georgia Northern District Court	Subaru of America, Inc.	2024-03-04	Closed.
3:22-cv-01349	California Southern District Court	Mercedes-Benz Group AG, Mercedes-Benz USA, LLC	2022-09-08	Closed.
3:22-cv-00301	California Southern District Court	Nissan North American Inc.	2022-03-04	Closed.
2:21-cv-01173	Washington Western District Court	Horatio Washington Depot Technologies LLC, et al.	2021-09-01	Closed. Note: Initial case appears to be styled GLEASON & ASSOCIATES PC v. HORATIO WASHINGTON DEPOT TECHNOLOGIES LLC et al.
3:21-cv-01565	California Southern District Court	Polaris Inc.	2021-09-03	Closed.

Post-Grant Proceedings

In addition to the district court litigation, U.S. Patent 8,315,769 has been the subject of post-grant review at the United States Patent and Trademark Office (USPTO).

• Ex Parte Reexamination: On March 25, 2026, Unified Patents filed an ex parte reexamination proceeding against the patent. On April 15, 2026, the Central Reexamination Unit (CRU) granted the request, finding "substantial new questions of patentability" for the challenged claims. This proceeding challenges the validity of the patent based on prior art and other patentability requirements. The reexamination was initiated in response to the patent's assertion against numerous entities in the automotive industry.

Proceedings overview

There are no AIA trial proceedings currently on file for U.S. Patent 8,315,769, according to the USPTO ODP API. This gives a defendant no PTAB-based defensive posture to leverage from prior proceedings.

Strategic summary

As of the current date, there are no records of AIA trial proceedings (Inter Partes Review, Post-Grant Review, or Covered Business Method reviews) being filed against U.S. Patent 8,315,769. This means that all claims of the patent remain untested in an AIA trial setting. The absence of such proceedings indicates that, to date, no entity has successfully challenged the patent's validity before the PTAB using the AIA trial mechanisms. This is a significant point for any defendant facing assertion of this patent, as it implies that the patent has not been subjected to the scrutiny of an IPR or PGR, which can often result in claim cancellation or narrowing.

However, it is important to note the previously identified ex parte reexamination proceeding (Unified Patents filed an ex parte reexamination proceeding on March 25, 2026, which was granted on April 15, 2026, finding "substantial new questions of patentability" for the challenged claims). While not an AIA trial, this reexamination is an ongoing challenge to the patent's validity, and its outcome could significantly impact the scope and enforceability of the claims.

Recommended next steps

• Monitor the ex parte reexamination: Closely track the ongoing ex parte reexamination proceeding initiated by Unified Patents on March 25, 2026 (granted on April 15, 2026). The outcome of this reexamination will be critical as it directly challenges the patentability of the claims and could lead to their amendment or cancellation.
• Consider initiating an AIA trial: Given the lack of prior AIA trial activity, a defendant facing assertion of this patent might consider filing an IPR, especially in light of the "substantial new questions of patentability" identified in the ex parte reexamination. This could offer an independent avenue to challenge the patent's validity based on prior art.

Inventors

• Alfred S. Braunberger: Employer not specified in the patent text, but assigned interest to Vision Works, LLC.
• Beau M. Braunberger: Employer not specified in the patent text, but assigned interest to Vision Works, LLC.

There is no information within the patent document to determine the inventors' employers at the time of filing. The inventors assigned their interest to Vision Works, LLC, and subsequently to Vision Works IP Corporation, on the same day the application was filed.

Original assignee

The entity named as the current assignee on the issued patent is Vision Works IP Corp. It is not readily determinable from the patent record or public information that Vision Works IP Corp ships a product embodying the claims. Their primary line of business, as evidenced by the extensive litigation history detailed previously, appears to be patent licensing and assertion. As of the current date, Vision Works IP Corp appears to be an operating entity for the purpose of patent assertion.

Assignment timeline

• 2011-11-22 (executed) / recorded 2011-11-22 — Reel 027266/0071

  • Conveyance: ASSIGNMENT OF ASSIGNORS INTEREST
  • Assignor: BRAUNBERGER, ALFRED S., BRAUNBERGER, BEAU S.
  • Assignee: VISION WORKS, LLC
  • Correspondent: MICHAEL MEYERS, ESQ., 5830 CANOGA AVE. STE 100, WOODLAND HILLS, CA 91367. This correspondent recurs in this chain.
  • Context: Inventors assign their interest to an LLC.

• 2011-11-22 (executed) / recorded 2011-11-22 — Reel 027266/0069

  • Conveyance: ASSIGNMENT OF ASSIGNORS INTEREST
  • Assignor: VISION WORKS, LLC
  • Assignee: VISION WORKS IP CORPORATION
  • Correspondent: MICHAEL MEYERS, ESQ., 5830 CANOGA AVE. STE 100, WOODLAND HILLS, CA 91367. This correspondent recurs in this chain.
  • Context: Internal transfer from one LLC to another IP-holding entity.

• 2012-01-30 (executed) / recorded 2012-01-30 — Reel 028509/0179

  • Conveyance: CORRECTIVE ASSIGNMENT TO CORRECT THE INVENTOR'S NAME BEAU M. BRAUNBERGER. PREVIOUSLY RECORDED ON REEL/FRAME: 027266/0069
  • Assignor: BRAUNBERGER, ALFRED S., BRAUNBERGER, BEAU M.
  • Assignee: VISION WORKS, LLC
  • Correspondent: MICHAEL MEYERS, ESQ., 5830 CANOGA AVE. SUITE 100, WOODLAND HILLS, CA 91367. This correspondent recurs in this chain.
  • Context: Corrective assignment to update an inventor's name in an earlier transfer.

Timeline diagram

timeline
    title Ownership of US 8315769
    2011 : Inventors assigned to Vision Works LLC
         : Vision Works LLC assigned to Vision Works IP Corp
    2012 : Corrective assignment
    2012 : Patent Issued
    2021 : First infringement suit filed
    2025 : Patent Expired

NPE / troll-pattern signals

1. Shell-entity transfer — Present. The patent was transferred from the inventors to "VISION WORKS, LLC" (Reel 027266/0071) and then immediately to "VISION WORKS IP CORPORATION" (Reel 027266/0069), both entity names commonly associated with IP holding or licensing rather than product manufacturing.
2. Known asserter in the chain — Present. Vision Works IP Corp is explicitly identified as the plaintiff in all listed litigation cases (as per the "Litigation History" section of this analysis).
3. Repeat correspondent across the chain — Present. MICHAEL MEYERS, ESQ., with the firm address 5830 CANOGA AVE. STE 100, WOODLAND HILLS, CA 91367, is listed as the correspondent for all recorded assignments: Reel 027266/0071, Reel 027266/0069, and Reel 028509/0179.
4. Cascading transfers — Present. Two assignments occurred on the same date, 2011-11-22, in quick succession from the inventors to Vision Works, LLC, and then to Vision Works IP Corporation (Reel 027266/0071 and Reel 027266/0069).
5. Pre-litigation transfer — Not present. The latest assignment is a corrective one from 2012-01-30. The earliest identified litigation filing date is 2021-09-01, which is significantly longer than 6 months after the last transfer.
6. Bankruptcy fire-sale — Not present. There is no indication of the original assignee or inventors undergoing bankruptcy proceedings related to these transfers.
7. Privateering — Not present. There is no evidence suggesting an operating company transferred the patent to an NPE to assert on its behalf. The initial transfers appear to be from the inventors to an IP holding structure.
8. Defensive aggregator (anti-NPE) — Not present. The patent is currently held by an entity that actively asserts patents, not a defensive aggregator.

Verdict

NPE — high confidence

This verdict is based on multiple strong signals: the rapid, sequential transfer of the patent from inventors to two shell-like entities ("LLC" and "IP CORPORATION") on the same day (Reel 027266/0071, Reel 027266/0069), the identification of the final assignee, Vision Works IP Corp, as a known patent asserter in numerous litigations, and the consistent appearance of the same correspondent attorney, Michael Meyers, Esq., across all recorded transfers (Reel 027266/0071, Reel 027266/0069, Reel 028509/0179).

Verification can be performed at the USPTO Patent Assignment Search page: https://assignmentcenter.uspto.gov/ (search for patent number 8315769).

Analysis of Prior Art Cited in U.S. Patent 8,315,769

During the examination of U.S. Patent 8,315,769 ('769 patent), the USPTO examiner cited several prior art references. The following analysis details the most relevant of these references and their potential impact on the patentability of the '769 patent's claims, particularly the independent claims 1, 9, and 21, which define the core invention related to an active suspension control system.

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1. U.S. Patent No. 7,047,120 B2 (to Breed)

• Full Citation: US 7,047,120 B2, "Arrangement to accurately measure vehicle motion and position," Inventor: David S. Breed, Assignee: Automotive Technologies International, Inc.
• Dates: Filed: July 1, 2002; Issued: May 16, 2006.
• Brief Description: Breed '120 discloses a system for accurately determining the motion and position of a vehicle. Crucially, it describes using a combination of accelerometers and gyroscopes (an "inertial measurement unit" or IMU) to measure vehicle accelerations. It explicitly teaches that the gyroscopes are used to determine the orientation of the accelerometers relative to the Earth's gravitational field. This allows the system to subtract the effects of gravity and inclination (e.g., being on a hill) to calculate the "true" or "absolute" acceleration of the vehicle in various axes, including lateral.
• Potential Anticipation of '769 Claims:
  • Claims 1, 9 (a), 21 (a): Breed '120 appears to teach the core concept of an "accelerometer-gyroscope for sensing an absolute lateral acceleration." The entire purpose of combining the two sensors in Breed '120 is to remove gravitational effects to get a true measure of the vehicle's acceleration, which is what the '769 patent defines as "absolute" acceleration. This reference provides a strong basis for anticipating the sensing element of the '769 claims.

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2. U.S. Patent No. 6,470,265 B1 (to Hac)

• Full Citation: US 6,470,265 B1, "Method and apparatus for controlling a vehicle suspension," Inventor: Aleksander Hac, Assignee: General Motors Corporation.
• Dates: Filed: May 23, 2001; Issued: October 22, 2002.
• Brief Description: Hac '265 describes a sophisticated vehicle suspension control system. It uses various sensors, including a lateral accelerometer and a yaw rate sensor (a type of gyroscope), to detect vehicle dynamics. The system processes these sensor inputs in a controller to actively adjust suspension components, such as dampers at each wheel, to improve handling and prevent rollover. It teaches controlling different parts of the suspension based on sensed vehicle motion.
• Potential Anticipation of '769 Claims:
  • Claims 1(b, c), 9(b, c, d), 21(b, c): Hac '265 discloses a controller ("apparatus") that receives signals based on lateral motion and sends control signals to individual suspension components. This maps directly onto the '769 patent's "suspension selector" and "plurality of controllers." Hac '265 describes a system where suspension characteristics are adjusted based on sensed lateral forces to improve performance, which aligns with the adjusting steps of claim 21. While it may not use the exact term "suspension selector," the function is present in its control logic.

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3. U.S. Patent No. 6,650,985 B2 (to Hac et al.)

• Full Citation: US 6,650,985 B2, "Rollover stability control for an automotive vehicle," Inventors: Aleksander Hac et al., Assignee: General Motors Corporation.
• Dates: Filed: October 24, 2001; Issued: November 18, 2003.
• Brief Description: This patent is also from the same assignee and lead inventor as Hac '265 and builds upon similar concepts. It specifically focuses on rollover prevention. The system uses a lateral accelerometer and a yaw rate sensor to calculate a "rollover index." Based on this index, a controller makes decisions to adjust vehicle systems, including active suspension components (like controllable anti-roll bars) and brakes, to counteract the tendency to roll over.
• Potential Anticipation of '769 Claims:
  • Claims 5, 13, 22: These dependent claims in the '769 patent specify that the purpose of the suspension adjustment is to move the center of gravity and more evenly distribute the load. Hac '985 directly addresses this by controlling suspension to maintain vehicle stability and prevent rollover, which inherently involves managing the vehicle's center of gravity and load distribution during cornering. This reference strengthens the argument that the purpose of the invention in '769 was already known in the art.

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4. U.S. Patent No. 6,529,810 B2 (to Naito et al.)

• Full Citation: US 6,529,810 B2, "Suspension control apparatus," Inventors: Gen Naito et al., Assignee: Toyota Jidosha Kabushiki Kaisha.
• Dates: Filed: November 20, 2000; Issued: March 4, 2003.
• Brief Description: Naito '810 discloses a suspension control apparatus that adjusts suspension damping force based on road surface conditions and vehicle behavior. It uses sensors for vertical acceleration and lateral acceleration to determine the appropriate control actions for the suspension system. The system is designed to distinguish between different driving scenarios (e.g., turning on a flat road vs. a banked road) and adjust the suspension actuators at the individual wheels accordingly.
• Potential Anticipation of '769 Claims:
  • Claims 1, 9, 21: Naito '810 teaches sensing lateral acceleration and using that data to adjust individual suspension characteristics. Like Hac '265, it discloses the fundamental feedback loop claimed in the '769 patent. The combination of Naito '810 (which shows the control loop) with Breed '120 (which shows how to get an "absolute" lateral acceleration reading) could be used to argue that the invention claimed in '769 would have been obvious to one of ordinary skill in the art.

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Summary of Prior Art Impact

The combination of the cited references presents a significant challenge to the validity of the independent claims of the '769 patent.

• Breed '120 teaches the use of an accelerometer-gyroscope combination to calculate absolute lateral acceleration, directly addressing the novel-sounding language in the preamble of claims 1, 9, and 21.
• Hac '265, Hac '985, and Naito '810 all teach the core concept of a vehicle control system that senses lateral forces (using accelerometers and often yaw rate sensors) and sends signals to control individual components of the suspension system to improve performance, stability, and prevent rollover.

An argument under 35 U.S.C. § 102 (anticipation) could potentially be made if a single one of these references discloses every element of a claim. More likely, a strong argument under 35 U.S.C. § 103 (obviousness) exists: it would have been obvious to a person skilled in automotive engineering to take the "absolute" acceleration sensor from Breed '120 and use it as the input for the active suspension control systems described in the Hac or Naito patents. This is the likely basis for the "substantial new questions of patentability" found in the recent ex parte reexamination.

Analysis of Obviousness under 35 U.S.C. § 103

This analysis examines whether the invention claimed in U.S. Patent 8,315,769 ('769 patent) would have been obvious to a Person Having Ordinary Skill in the Art (PHOSITA) at the time the invention was made. An invention is considered obvious if the differences between the claimed invention and the prior art are such that the subject matter as a whole would have been obvious to a PHOSITA. This analysis relies on the prior art references detailed in the preceding section.

A PHOSITA in this technical field would likely be an automotive engineer or a control systems engineer with a bachelor's degree in mechanical or electrical engineering and several years of experience in vehicle dynamics, sensor integration, and active suspension control systems.

The independent claims (1, 9, and 21) of the '769 patent can be rendered obvious by combining the teachings of the prior art, most notably by combining U.S. Patent No. 7,047,120 B2 (Breed) with either U.S. Patent No. 6,470,265 B1 (Hac '265) or U.S. Patent No. 6,529,810 B2 (Naito).

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Primary Combination: Breed '120 and Hac '265

A strong case for obviousness exists by combining the teachings of Breed '120 and Hac '265.

• Claim Elements Taught by the Combination:

  • Element (a): an accelerometer-gyroscope for sensing an absolute lateral acceleration (from claims 1 and 9) / sensing a lateral acceleration (from claim 21):
    Breed '120 explicitly teaches this element. It discloses an inertial measurement unit comprising both accelerometers and gyroscopes for the precise purpose of determining the vehicle's orientation relative to gravity. This allows the system to calculate the "true" or "absolute" acceleration by subtracting gravitational components, which is the exact concept claimed in the '769 patent.

  • Elements (b) and (c): a suspension selector and a plurality of controllers for individually controlling one or more suspension systems (from claims 1 and 9) / sending a signal to a plurality of control devices and adjusting a suspension characteristic (from claim 21):
    Hac '265 clearly discloses these elements. It describes a comprehensive apparatus for vehicle suspension control that uses sensor inputs (including a lateral accelerometer) to actively adjust individual suspension components. The control logic within Hac '265 performs the function of the claimed "suspension selector" and "plurality of controllers" by receiving sensor data and directing signals to specific suspension actuators at different wheels of the vehicle.

• Motivation to Combine:
  A PHOSITA would have been motivated to combine the teachings of these two patents for a clear and predictable purpose: to improve the performance of an existing active suspension system.

  The active suspension control system described in Hac '265 relies on accurate sensor data to function effectively. However, a simple lateral accelerometer, as used in Hac, is susceptible to errors on banked curves or inclines where gravity is misread as lateral force. This limitation was well-understood in the field of vehicle dynamics.

  Breed '120 provides a direct solution to this known problem by teaching a method to obtain a more accurate, gravity-corrected ("absolute") lateral acceleration measurement. A PHOSITA tasked with improving the robustness and accuracy of the Hac '265 system would have found it obvious to replace the standard lateral accelerometer with the more advanced inertial measurement unit taught by Breed '120. This is not an inventive leap, but rather the application of a known, improved component (Breed's sensor) into an existing system (Hac's controller) to achieve a predictable improvement in performance. The combination would yield a more reliable suspension control system, which is a recognized goal in the art.

Secondary Combination: Breed '120 and Naito '810

A similar argument for obviousness can be made by combining Breed '120 with Naito '810.

• Claim Elements Taught by the Combination:

  • Sensing absolute lateral acceleration: As before, this is taught by Breed '120.
  • Control and Adjustment of Suspension: Naito '810 discloses a suspension control apparatus that uses lateral acceleration data to adjust suspension actuators at individual wheels. Its control unit serves the same function as the "suspension selector" and "controllers" in the '769 patent claims, thereby teaching the control feedback loop.

• Motivation to Combine:
  The motivation is identical to the first combination. Naito '810's system, which seeks to distinguish between different road conditions and turning scenarios, would directly benefit from a more accurate lateral acceleration input. A PHOSITA would be motivated to incorporate the absolute sensor from Breed '120 into the Naito '810 system to enhance its ability to make correct adjustments, especially on banked or uneven road surfaces. The result—a more precise suspension adjustment—is the expected outcome of using a superior sensor.

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Conclusion on Obviousness

The independent claims of U.S. Patent 8,315,769 appear obvious under 35 U.S.C. § 103. The core elements of the claimed invention were present in the prior art. Specifically, the concept of using an accelerometer-gyroscope pair to calculate absolute acceleration was taught by Breed '120, and the use of control systems to adjust individual suspension components based on lateral acceleration was well-established by references like Hac '265 and Naito '810.

A person of ordinary skill in the art would have been motivated to combine these teachings to create a more robust and accurate active suspension system. Such a combination represents a predictable substitution of one known element for another to obtain a predictable result, which falls squarely within the scope of an obviousness rejection. This conclusion is consistent with the finding of "substantial new questions of patentability" in the ex parte reexamination initiated in March 2026.

Analysis of Patent Term and Related Applications for U.S. Patent 8,315,769

As of April 30, 2026, the following analysis details the patent term, application history, and projected expiration for U.S. Patent No. 8,315,769.

Patent Term Adjustments (PTA) and Extensions (PTE)

• Patent Term Adjustment (PTA): There are no Patent Term Adjustments recorded for U.S. Patent 8,315,769. The application and issuance timeline did not accrue any statutory delays that would warrant an adjustment to the patent's term.
• Patent Term Extension (PTE): There are no Patent Term Extensions for this patent. PTE under 35 U.S.C. § 156 is typically granted for delays caused by pre-market regulatory review by agencies like the FDA and does not apply to the technology covered by this patent.

Application Continuity and Family Members

U.S. Patent 8,315,769 is part of a large family of patents and applications stemming from earlier filings. The continuity chain establishes the priority date, which is crucial for determining the patent's term.

• Application Number: The application that matured into this patent is 13/302,965, filed on November 22, 2011.

• Priority Claim / Parent Applications: The patent claims the benefit of a long chain of preceding applications. The "RELATED APPLICATION" section of the patent specification explicitly states this lineage. The earliest non-provisional application in this chain, which sets the patent term, is:

  • U.S. Application No. 11/243,364, filed on October 3, 2005 (now U.S. Patent 7,239,953).

  This application, in turn, claims priority to:

  • U.S. Provisional Application No. 60/616,400, filed on October 5, 2004.

• Continuation and Related Applications: The patent family has been extended through numerous continuation applications filed after U.S. Patent 8,315,769 was filed. These applications claim priority back to the original 2005 filing date and represent ongoing efforts by the assignee to pursue additional claims related to the technology. Notable child applications include:

  • U.S. Application No. 13/650,017 (now U.S. Patent 8,682,558)
  • U.S. Application No. 14/220,511 (now U.S. Patent 9,123,249)
  • U.S. Application No. 14/807,688 (now U.S. Patent 9,643,538)
  • U.S. Application No. 15/471,772 (now U.S. Publication 2017/0259738)

• Divisional Applications: There is no record of any divisional applications related to this patent. The continuity is established through continuation and continuation-in-part applications.

Projected and Actual Expiration Date

The term of a U.S. patent is twenty years from the filing date of the earliest U.S. non-provisional application to which it claims priority.

• Earliest Non-Provisional Filing Date: October 3, 2005 (from U.S. Application No. 11/243,364).
• Calculation: October 3, 2005 + 20 years.
• Expiration Date: October 3, 2025.

As of the current date of April 30, 2026, U.S. Patent 8,315,769 has expired. Its full statutory term has concluded, and it is now in the public domain. This is consistent with the "Expired - Lifetime" status noted in public patent databases.

Here is the comprehensive "Defensive Disclosure" document for U.S. Patent 8,315,769, designed to establish prior art against future incremental inventions.

Defensive Disclosure and Prior Art Publication

Title: Systems and Methods for Active Dynamic Response Based on Absolute Force Vectors
Publication Date: April 26, 2026
Summary: The following technical disclosures describe various implementations, extensions, and applications of a system that senses absolute lateral acceleration using a combined accelerometer-gyroscope sensor and uses this data to actively control a multi-part suspension or stabilization system. These disclosures are intended to enter the public domain as prior art.

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Axis 1: Material & Component Substitution

1.1. Magnetorheological Fluid-Based Active Suspension System

• Enabling Description: This variation replaces conventional hydraulic or pneumatic suspension actuators with magnetorheological (MR) fluid dampers. The core accelerometer-gyroscope unit (an MPU-6050 or similar MEMS IMU) calculates the absolute lateral acceleration. This data is fed to a suspension selector implemented in a microcontroller (e.g., an STM32 series). The plurality of controllers are high-current PWM drivers. The selector logic translates the lateral acceleration magnitude into a specific current value for the PWM drivers connected to the electromagnetic coils within each MR damper. An increase in current thickens the MR fluid almost instantaneously (<10 milliseconds), thereby stiffening the suspension on the side of the vehicle experiencing the outward lateral force. This provides a continuously variable and rapid response to counteract body roll.

• Mermaid Diagram:

  graph TD
      A[MEMS IMU Sensor] -- Raw Accel/Gyro Data --> B(Microcontroller: Suspension Selector);
      B -- Calculated Absolute Lateral G-Force --> C{Control Logic};
      C -- Current Value for Left Side --> D1[PWM Driver Q1];
      C -- Current Value for Right Side --> D2[PWM Driver Q2];
      D1 -- Modulated Current --> E1[MR Damper Left];
      D2 -- Modulated Current --> E2[MR Damper Right];
  

1.2. Distributed Piezoelectric Sensor Network for Chassis Strain Detection

• Enabling Description: This derivative replaces a central IMU with a distributed network of piezoelectric strain sensors laminated directly onto the vehicle's chassis at key structural points (e.g., suspension mounting points). When the vehicle experiences lateral force, the chassis flexes, inducing a measurable voltage in the piezoelectric sensors. A centralized suspension selector processor collects voltage readings from all sensors. By analyzing the differential signals and patterns of strain across the chassis using a pre-calibrated model, the processor infers the magnitude and direction of the lateral acceleration. This data is then used to command individual air suspension controllers to adjust ride height and stiffness to counteract the chassis flex and body roll.

• Mermaid Diagram:

  flowchart LR
      subgraph Vehicle Chassis
          P1(Piezo Sensor FL);
          P2(Piezo Sensor FR);
          P3(Piezo Sensor RL);
          P4(Piezo Sensor RR);
      end
      subgraph Control Unit
          SS(Suspension Selector);
          C1(Controller FL);
          C2(Controller FR);
          C3(Controller RL);
          C4(Controller RR);
      end
      P1 & P2 & P3 & P4 -- Strain Voltage Signals --> SS;
      SS -- Inferred Lateral Force --> SS;
      SS -- Control Signals --> C1 & C2 & C3 & C4;
      C1 --> A1(Air Suspension FL);
      C2 --> A2(Air Suspension FR);
      C3 --> A3(Air Suspension RL);
      C4 --> A4(Air Suspension RR);
  

1.3. Fiber Optic Gyroscope (FOG) with Solid-State Accelerometers

• Enabling Description: For applications requiring extreme precision and immunity to electromagnetic interference (EMI), such as military vehicles or high-speed rail, the standard MEMS gyroscope is replaced with a Fiber Optic Gyroscope (FOG). The FOG measures rotation by detecting phase shifts in light traveling through a long fiber optic coil (Sagnac effect). It is paired with high-precision solid-state capacitive accelerometers. The suspension selector, implemented on an FPGA for parallel processing, fuses the FOG and accelerometer data to compute absolute lateral acceleration with near-zero drift. The controllers then actuate high-speed hydraulic servo valves in the suspension system, providing precise control under severe operational conditions.

• Mermaid Diagram:

  sequenceDiagram
      participant FOG as Fiber Optic Gyro
      participant Accel as Capacitive Accelerometer
      participant FPGA as FPGA (Suspension Selector)
      participant Servo as Hydraulic Servo Controller
      participant Actuator as Suspension Actuator
  
      loop Data Fusion
          FOG->>FPGA: Phase Shift Data (Rotation)
          Accel->>FPGA: Capacitance Change Data (Acceleration)
      end
      FPGA->>FPGA: Compute Absolute Lateral Accel
      FPGA->>Servo: Actuation Signal (e.g., Target Pressure)
      Servo->>Actuator: Command Hydraulic Valve
  

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Axis 2: Operational Parameter Expansion

2.1. Nanoscale Atomic Force Microscope (AFM) Cantilever Stabilization

• Enabling Description: At the nanoscale, the invention is adapted for active vibration cancellation in an Atomic Force Microscope (AFM). The "vehicle" is the AFM's probe cantilever. A micro-IMU, integrated near the cantilever base, detects external lateral vibrations (e.g., from building tremors) in the kHz range. The suspension selector is a digital signal processor (DSP) that analyzes the vibration signature and generates an inverse-phase signal. The controllers are piezoelectric actuators bonded to the cantilever's base. By applying the inverse-phase signal, the actuators induce a counter-vibration, effectively stabilizing the cantilever tip to maintain sub-nanometer imaging resolution despite environmental noise.

• Mermaid Diagram:

  graph TD
      A[External Vibration Source] --> B(AFM Cantilever);
      B -- Sensed Vibration --> C(Micro-IMU);
      C -- High-Frequency Lateral Data --> D{DSP};
      D -- Generates Inverse Phase Signal --> E(Piezoelectric Actuator Controller);
      E -- Control Voltage --> F(Piezo Actuators);
      F -- Counter-Vibration --> B;
      subgraph Stabilization Loop
      C; D; E; F;
      end
  

2.2. Cryogenic Rover Suspension for Extraterrestrial Operations

• Enabling Description: This system is designed for a planetary rover operating at cryogenic temperatures (e.g., -180°C on Titan). All components are radiation-hardened and designed for extreme cold. The accelerometer-gyroscope is a specialized unit with a wide operational temperature range. The suspension selector and controllers are housed in a warmed electronics box. The suspension system itself consists of individually controlled electromechanical actuators that can adjust the preload on a nickel-titanium (Nitinol) alloy spring system, which retains its superelastic properties at low temperatures. When the IMU detects absolute lateral acceleration (e.g., while traversing a steep, icy crater wall), the controllers increase current to the actuators on the downhill side, stiffening the suspension to prevent rollover in a low-gravity, low-traction environment.

• Mermaid Diagram:

  stateDiagram-v2
      [*] --> Traversing
      Traversing: Rover moving on stable ground.
      Traversing --> Adjusting: Lateral G-Force > Threshold
      Adjusting: Rover on slope. IMU detects slip/tilt.
      Adjusting: Suspension selector commands downhill actuators.
      Adjusting: Nitinol spring preload is increased via actuators.
      Adjusting: Center of gravity is stabilized.
      Adjusting --> Traversing: Lateral G-Force < Threshold
  

2.3. Active Mass Damper Control in Civil Structures

• Enabling Description: For industrial-scale application, the system controls an Active Mass Damper (AMD) in a skyscraper. The "suspension system" is a massive concrete block (the damper) on a hydraulic sled. A network of high-sensitivity accelerometer-gyroscope sensors placed on the building's upper floors detects low-frequency lateral sway from wind or seismic events. The suspension selector is a central control server that computes the building's sway vector in real-time. It commands the controllers—large-scale hydraulic pumps and actuators—to move the AMD in the opposite direction of the sway. This counter-movement dissipates the energy and stabilizes the entire structure.

• Mermaid Diagram:

  flowchart TD
      A[Wind/Seismic Force] --> B(Building Structure);
      B -- Sway Detected --> C(IMU Sensor Network);
      C -- Sway Vector Data --> D{Central Control Server};
      D -- Counter-Command --> E(Hydraulic Pump Controllers);
      E -- High-Pressure Fluid --> F(Hydraulic Actuators);
      F -- Moves AMD --> G[Active Mass Damper];
      G -- Exerts Counter-Force --> B;
  

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Axis 3: Cross-Domain Application

3.1. Aerospace: Active Jitter Compensation for Satellite Laser Communication

• Enabling Description: In a satellite, the system provides fine-pointing for a laser communication terminal. The accelerometer-gyroscope sensor is mounted on the terminal's optical bench to detect high-frequency jitter caused by reaction wheels or thruster firings. The suspension selector is a high-speed controller that directs two controllers for a fast-steering mirror (FSM). The FSM is the "suspension," a small mirror tilted by piezoelectric actuators on two axes. Based on the lateral jitter detected, the controller adjusts the FSM's angle in real-time to keep the outgoing laser beam locked onto the receiving station on Earth or another satellite, compensating for the host satellite's vibrations.

• Mermaid Diagram:

  sequenceDiagram
      participant JitterSource as Satellite Vibration
      participant IMU as Optical Bench IMU
      participant FSM_Controller as Fast Steering Mirror Controller
      participant FSM as Fast Steering Mirror
      participant Laser as Laser Beam
  
      JitterSource->>IMU: Senses Lateral Jitter
      IMU->>FSM_Controller: Jitter Vector Data
      FSM_Controller->>FSM: Piezo Actuator Commands
      FSM->>Laser: Adjusts Beam Angle
      Note right of Laser: Beam is stabilized despite jitter
  

3.2. AgTech: Self-Leveling Boom for Agricultural Sprayers

• Enabling Description: This system is applied to a large agricultural sprayer with a wide boom (e.g., >100 feet). An accelerometer-gyroscope is placed at the center of the boom. As the sprayer moves over uneven terrain, the IMU detects absolute lateral acceleration and roll. The suspension selector logic determines which side of the boom is too high or low. It sends signals to controllers which operate hydraulic actuators located at the boom's pivot point and at suspension points along the boom arms. The actuators adjust the boom's height and angle to keep it perfectly parallel to the ground, ensuring uniform application of fertilizer or pesticides and preventing the boom from striking the ground.

• Mermaid Diagram:

  graph LR
      A[Uneven Terrain] --> B(Sprayer Vehicle);
      B -- Causes Boom Roll/Sway --> C[Boom Structure];
      C -- Roll/Sway Sensed --> D(Central IMU);
      D -- Absolute Roll/Accel Data --> E{Boom Control Unit};
      E -- Correction Signal --> F(Hydraulic Valve Controllers);
      F -- Actuates --> G(Hydraulic Cylinders);
      G -- Adjusts Boom Angle/Height --> C;
  

3.3. Consumer Electronics: Multi-Axis Haptic Feedback Controller

• Enabling Description: In a handheld gaming controller, the core mechanism is used to generate realistic haptic feedback. A central accelerometer-gyroscope detects the user's movements (shake, tilt, turn). This motion data is processed by the controller's main CPU, which acts as the suspension selector. Instead of controlling vehicle suspension, it directs multiple controllers for individual Linear Resonant Actuators (LRAs) or voice coil motors placed at different points within the controller shell. If the user makes a sharp left turn in a game, the CPU activates the LRA on the right side of the controller, simulating the feeling of inertial force. This creates a more immersive experience than simple rumble feedback.

• Mermaid Diagram:

  classDiagram
  class GameController {
      +IMU sensor
      +CPU processor
      +LRA_Controller_Left
      +LRA_Controller_Right
      +LRA_Left
      +LRA_Right
  }
  class IMU {
      +getAbsoluteLateralMotion()
  }
  class CPU {
      +processGameLogic()
      +calculateHapticResponse()
  }
  class LRA_Controller {
      +driveMotor(intensity)
  }
  GameController *-- IMU
  GameController *-- CPU
  CPU ..> LRA_Controller : directs
  GameController "1" *-- "2" LRA_Controller
  

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Axis 4: Integration with Emerging Tech

4.1. AI-Driven Predictive Suspension using an IoT Sensor Fleet

• Enabling Description: This system elevates the reactive suspension to a predictive one. Each vehicle is an IoT device, equipped with the accelerometer-gyroscope and additional sensors (GPS, camera, temperature). It streams suspension event data (lateral G-force, control action, location) to a central cloud platform. A machine learning model is trained on this fleet-wide data to correlate road features (from GPS/camera data) with required suspension adjustments. The trained model is deployed back to the vehicle's edge computer (the suspension selector). Now, as the vehicle approaches a known sharp curve, the AI model predicts the necessary lateral force compensation and pre-emptively stiffens the outer suspension before the turn begins, providing superior stability.

• Mermaid Diagram:

  flowchart TD
      subgraph Cloud
          D[Fleet Data Lake]
          E[ML Training Pipeline]
          F[Predictive Suspension Model]
      end
      subgraph Vehicle (Edge)
          A[IoT Sensor Suite]
          B(Edge AI Processor)
          C(Suspension Controllers)
          G(Suspension Actuators)
      end
      A -- Real-time Data --> B
      A -- Anonymized Data --> D
      E -- Trains on --> D
      F -- Deployed to --> B
      B -- Predictive Commands --> C
      B -- Reactive Commands --> C
      C --> G
  

4.2. Blockchain-Verified Performance Tuning and Accident Forensics

• Enabling Description: In this variation, every significant suspension adjustment event is recorded as an immutable transaction on a private blockchain. The suspension selector acts as a blockchain node. When the absolute lateral acceleration exceeds a predefined threshold (e.g., 0.5 G), the selector creates a data block containing the sensor reading, GPS coordinates, timestamp, and the control action taken by the controllers. This block is cryptographically signed and added to the vehicle's ledger. This provides an unalterable log for professional racing teams to verify performance tuning or for insurance companies to perform detailed accident reconstruction.

• Mermaid Diagram:

  sequenceDiagram
      participant IMU
      participant SuspensionSelector as Selector (Node)
      participant Blockchain
      participant Controllers
  
      IMU->>SuspensionSelector: Lateral Accel > 0.5G
      SuspensionSelector->>SuspensionSelector: Create Transaction Block (Data, GPS, Timestamp)
      SuspensionSelector->>Blockchain: Sign & Submit Block
      Blockchain-->>SuspensionSelector: Transaction Confirmed
      SuspensionSelector->>Controllers: Send Adjustment Command
  

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Axis 5: The "Inverse" or Failure Mode

5.1. Failsafe "Acoustic Signature" Mode

• Enabling Description: This system is designed for a safe failure mode. If the primary accelerometer-gyroscope sensor fails (detected via a self-test diagnostic), the suspension selector switches to a secondary, "inverse" sensing mode. It uses a high-sensitivity microphone to listen to the acoustic signature of the tire noise. An onboard processor, trained to recognize the sound patterns associated with high lateral load (tire scrub), infers a high-G condition. While less precise, this allows the system to enter a limited-functionality state, stiffening the suspension to a default "safe" setting (e.g., 75% stiffness) during high-load events, rather than failing completely open. A warning is simultaneously issued to the driver.

• Mermaid Diagram:

  stateDiagram-v2
      state "Normal Operation" as Normal
      state "Limited Functionality" as Limited
      state "Failure" as Fail
  
      [*] --> Normal
      Normal --> Fail: IMU Self-Test Fails
      Fail --> Limited: Switch to Acoustic Sensing
      Limited: Listen for tire scrub audio signature.
      Limited: Apply default 'safe' stiffness on high load.
      Limited: Issue driver warning.
      Limited --> [*]: System Shutdown/Repair
      Normal --> [*]: System Shutdown
  

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Combination Prior Art with Open Standards

Scenario 1: AUTOSAR-Compliant Suspension Control Module

• Enabling Description: The system is implemented as a set of AUTOSAR-compliant software components (SW-Cs) within a vehicle's ECU. The accelerometer-gyroscope driver is a Complex Device Driver (CDD) feeding data to an Absolute_Accel_Sensor_SWC. This component communicates its output via the Runtime Environment (RTE) to a Suspension_Selector_SWC. This selector component then sends control commands, again via the RTE, to four individual Suspension_Controller_SWC instances. All communication occurs over a standardized CAN-FD or Automotive Ethernet bus, making the entire system a modular and interoperable solution within any AUTOSAR architecture.

Scenario 2: DDS-Based Real-Time Control Network

• Enabling Description: The system components communicate using the Data Distribution Service (DDS) real-time publish-subscribe protocol. The IMU is a "Publisher" on the DDS Global Data Space, publishing to the topic Vehicle_Dynamics/Absolute_Lateral_Acceleration. The Suspension Selector is a "Subscriber" to this topic. After processing, it becomes a "Publisher" to the topic Suspension_Control/Target_Stiffness, which is subscribed to by the individual Suspension Controller nodes. This decouples the software, guarantees quality-of-service (QoS) for real-time data delivery, and allows for dynamic addition or removal of components.

Scenario 3: ROS2 Node Architecture for Autonomous Vehicles

• Enabling Description: The system is integrated into a ROS2 (Robot Operating System 2) framework for an autonomous vehicle. A imu_driver node publishes sensor_msgs/msg/Imu data. A suspension_selector_node subscribes to the /imu topic, performs its calculations, and publishes a custom message type, autovehicle_msgs/msg/SuspensionState, to a /suspension_command topic. Four suspension_controller_nodes (e.g., /fl_suspension_controller) subscribe to this topic, filter for their respective wheel commands, and interface with the hardware. This architecture allows the entire system to be easily simulated in Gazebo and integrated with other autonomous driving components like the navigation and path planning stacks.