PTAB

IPR2015-00794

Ford Motor Co v. Paice Corp

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Method of Control of a Hybrid Vehicle
  • Brief Description: The ’347 patent discloses a control method for a hybrid electric vehicle that utilizes an internal combustion engine, one or more electric motors, and a battery. The method selects among different operating modes (e.g., motor-only, engine-only, or combined) by comparing the vehicle's instantaneous required torque (road load) to predetermined torque setpoints to optimize performance and efficiency.

3. Grounds for Unpatentability

Ground 1: Obviousness over Core Hybrid Control Teachings - Claims 23, 24, 28, 30, and 32 are obvious over Ibaraki in view of POSA knowledge.

  • Prior Art Relied Upon: Ibaraki (Patent 5,789,882).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Ibaraki discloses all elements of the challenged claims. Ibaraki teaches a hybrid vehicle control apparatus that selects between a MOTOR DRIVE mode, an ENGINE DRIVE mode, and an ENGINE-MOTOR DRIVE mode using a data map based on "vehicle drive torque" and vehicle speed. Petitioner asserted that Ibaraki's boundary lines on its control maps (e.g., "boundary line B") represent the claimed "setpoint (SP)" for transitioning between modes. For example, when the required torque is below the setpoint, Ibaraki operates in MOTOR DRIVE mode (as claimed). When the torque is between the lower setpoint and an upper boundary, it operates in ENGINE DRIVE mode. When torque exceeds the upper boundary (representing the engine's maximum torque output, or MTO), it operates in ENGINE-MOTOR DRIVE mode. Ibaraki also discloses using the engine to charge the battery when its state of charge is low, satisfying further limitations.
    • Motivation to Combine (for §103 grounds): This ground primarily relied on a single reference, with a POSA applying general knowledge. Petitioner argued a POSA would understand Ibaraki's efficiency maps and control thresholds to represent the claimed setpoints. For instance, a POSA would recognize that the torque setpoint for engaging the engine must be substantially less than its MTO for the engine to have a useful operating range, as taught by Ibaraki's engine performance map.
    • Expectation of Success: A POSA would have a high expectation of success in implementing the claimed method, as it represents the application of fundamental engineering principles to the hybrid control system explicitly detailed in Ibaraki.

Ground 2: Obviousness over Ibaraki and Vittone - Claim 39 is obvious over Ibaraki in view of Vittone and POSA knowledge.

  • Prior Art Relied Upon: Ibaraki (Patent 5,789,882) and Vittone (a 1994 publication titled "Fiat Conceptual Approach to Hybrid Cars Design").
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground addressed claim 39, which adds limiting the rate of change of engine torque output to maintain combustion near the stoichiometric ratio for emission control. While Ibaraki states a goal of reducing emissions, it does not detail this specific technique. Vittone explicitly teaches a "driving torque management" strategy for hybrid vehicles that limits the engine's rate of torque change during transient conditions to maintain stoichiometric control. Vittone further discloses using the electric motor to supply supplemental torque to meet driver demand when the engine's torque output is limited for emission purposes.
    • Motivation to Combine: A POSA would combine Vittone's well-known stoichiometric control strategy with Ibaraki’s base hybrid system to further Ibaraki's stated goal of reducing exhaust emissions. This combination would be a predictable improvement, as applying known emission control techniques to an internal combustion engine was a common design objective.
    • Expectation of Success: The combination would be a mere software modification to Ibaraki’s controller to implement Vittone’s control logic, providing a high expectation of success.

Ground 3: Obviousness over Ibaraki and Frank - Claims 25 and 26 are obvious over Ibaraki in view of Frank and POSA knowledge.

  • Prior Art Relied Upon: Ibaraki (Patent 5,789,882) and Frank (Patent 6,116,363).
  • Core Argument for this Ground:
    • Prior Art Mapping: These claims add logic to control the transition between modes to prevent rapid and unwanted cycling when the required torque hovers near a setpoint. The claims require the transition condition to persist for a predetermined time before the mode is changed. Petitioner argued Ibaraki’s system would be prone to such undesirable cycling. Frank explicitly addresses this known "frequent cycling" problem in hybrid vehicles and teaches the solution of adding a time delay to the control logic before permitting a switch between operating modes.
    • Motivation to Combine: A POSA would recognize that Ibaraki's setpoint-based switching logic could lead to erratic behavior around the setpoint, causing component wear and poor drivability. To solve this known problem, a POSA would be motivated to implement a known solution like the time delay taught by Frank.
    • Expectation of Success: A POSA would expect success, as implementing a time-based delay is a simple and common software modification to control logic used to prevent system instability.
  • Additional Grounds: Petitioner asserted additional obviousness challenges based on combinations of Ibaraki with Yamaguchi (for pre-heating the engine to reduce cold-start emissions), Ibaraki ’626 (for adding fault-mode operation logic), Lateur (for implementing cruise control), and knowledge of prior art systems (for establishing specific setpoint percentages relative to MTO).

4. Key Claim Construction Positions

  • "road load (RL)": Petitioner proposed that for IPR purposes, this term should be construed as "the amount of instantaneous torque required to propel the vehicle, be it positive or negative." This construction was argued to be consistent with prior PTAB decisions.
  • "setpoint (SP)": Petitioner argued the broadest reasonable construction is a "predetermined torque value." This was based on the specification and the prosecution history, where the patentee defined the setpoint relative to the engine’s maximum torque output (MTO) to overcome a rejection. Petitioner contended this was narrower than a district court construction of "a definite, but potentially variable value," arguing the patent's own text fixed the setpoint as a specific torque value.

5. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 23-30, 32, and 39-41 of Patent 7,104,347 as unpatentable.