PTAB

IPR2018-00205

SZ DJI Technology Co Ltd v. Drone Control LLC

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Radio Controlled (RC) Aircraft with Coordinate System Transformation
  • Brief Description: The ’368 patent describes a system to solve the problem of non-intuitive control of an RC aircraft when the aircraft's heading does not align with the operator's orientation. The invention transforms control commands (e.g., for roll and pitch) from a first coordinate system based on the perspective of the user's remote control device into a second coordinate system based on the perspective of the RC aircraft, allowing the aircraft to maneuver relative to the user regardless of its yaw orientation.

3. Grounds for Unpatentability

Ground 1: Claims 1-6 and 11-14 are anticipated by and/or obvious over Thornberg.

  • Prior Art Relied Upon: Thornberg (Patent 5,552,983).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Thornberg taught every limitation of the independent claims. Thornberg explicitly addressed the same "non-intuitive control" problem and disclosed a system for a remotely operated vehicle (including aircraft) that can operate in multiple reference modes. In its "operator reference mode," commands from the operator's control panel are issued from the operator's perspective (the "first coordinate system") and are transformed into the vehicle's frame of reference (the "second coordinate system") using the exact same rotation matrix transformation taught in the ’368 patent. Thornberg disclosed a navigation system (e.g., a ring laser gyro) to generate motion data (the vehicle's heading) and a flight control computer to perform the transformation, directly mapping to the claimed motion sensing and processing modules.
    • Motivation to Combine (for §103 grounds): For any elements argued as obvious, Petitioner contended that a person of ordinary skill in the art (POSITA) would have understood that Thornberg's system used conventional RF signals and control components to implement the disclosed functionality.
    • Expectation of Success: As Thornberg described a complete, functional system using conventional components to solve the very same problem, a POSITA would have had a high expectation of success.

Ground 2: Claims 1-5 and 11-13 are anticipated by and/or obvious over Muramatsu, alone or in view of Thornberg.

  • Prior Art Relied Upon: Muramatsu (JP Patent Publication 2001-209427) and Thornberg (Patent 5,552,983).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that Muramatsu also solved the same intuitive control problem for an unmanned helicopter. Muramatsu disclosed a system where steering inputs based on the operator's viewing direction are transformed into the helicopter's perspective. It used magnetic sensors on both the operator (a cap) and the helicopter to determine their respective orientations relative to a reference direction (north) and transformed the commands using the same underlying rotation matrix as the ’368 patent. Muramatsu's system included a receiver, a motion sensing module (magnetic bearing detector), and a processing module (steering rate conversion means) that perform the same functions as the claimed elements.
    • Motivation to Combine (for §103 grounds): Petitioner argued that if Muramatsu's two-step transformation (user input -> earth coordinates -> aircraft coordinates) was deemed distinct from the claimed direct transformation, it would have been obvious to modify it in view of Thornberg. A POSITA would combine Thornberg's direct user-to-vehicle transformation method with Muramatsu's system to simplify the process and reduce computational complexity, a well-known engineering goal.
    • Expectation of Success: Since both references taught operable systems using the same mathematical principles, a POSITA would have expected success in implementing Muramatsu's system or combining it with Thornberg's slightly more direct transformation method.

Ground 3: Claims 7 and 15 are obvious over Thornberg in view of Kotake.

  • Prior Art Relied Upon: Thornberg (Patent 5,552,983) and Kotake (Japanese Patent Publication No. 1996-10451).

  • Core Argument for this Ground:

    • Prior Art Mapping: This ground built upon the base system of Thornberg. Claims 7 and 15 add the limitation of generating lift control data based on the weight of the RC aircraft. Petitioner argued that while Thornberg did not explicitly teach this, Kotake did. Kotake disclosed an RC helicopter used for agricultural spraying that could automatically maintain a "proper altitude" even as its weight changed due to the dispensing of chemicals.
    • Motivation to Combine: A POSITA would have been motivated to incorporate Kotake's automatic altitude-maintenance feature into Thornberg's system. Thornberg itself suggested its UAV could be used for delivering ordnance or supplies, which involves weight changes. Adding Kotake's known technique for compensating for such changes would be an advantageous and predictable improvement to enhance the stability and functionality of Thornberg's vehicle during payload delivery missions.
    • Expectation of Success: Combining a known automatic hovering/altitude control system with a known flight control system was a straightforward integration of complementary technologies with a high expectation of success.

  • Additional Grounds: Petitioner asserted additional obviousness challenges, primarily by adding single-feature prior art to the base systems of Thornberg or Muramatsu. These included adding Karem (Patent 6,584,382) for its disclosure of proportional yaw-velocity control (for claims 8 and 16) and Rivers (Application # 2005/0127242) for its disclosure of a payload dispensing module to launch an object with a parachute (for claims 9-10 and 17-18).

4. Key Claim Construction Positions

  • "coordinate system . . . from a perspective of the RC aircraft": Petitioner proposed this term means a "coordinate system based on the orientation of the RC aircraft." This construction was based on the specification's description and figures showing the system's roll, pitch, and yaw axes aligned with the aircraft's body.
  • "coordinate system . . . from a perspective of the remote control device": Petitioner proposed this term means a "coordinate system based on the orientation of the remote control device." This was argued as consistent with the patent's goal of making control intuitive relative to the user, whose perspective is defined by the orientation of the control device.
  • "launch[] an object": Petitioner argued this term simply means to "release an object" and does not require propulsion. This construction was based on specification language describing a launch module that "selectively releases" or "dropped" objects.

5. Relief Requested

  • Petitioner requested institution of an IPR and cancellation of claims 1-18 of the ’368 patent as unpatentable.