Steering stabilizing apparatus for a model vehicle

• US 9,975,056 B2
• Filed: 04/18/2016
• Issued: 05/22/2018
• Est. Priority Date: 04/17/2015
• Status: Active Grant

• Current Assignee: Traxxas LP (Traxxas)
• Original Assignee: Traxxas LP (Traxxas)
• Inventors: Kawamura, Thomas Michael, Erhart, Wesley Ronald, Schmitz, Scott Rollin Michael
• Primary Examiner(s): Badii, Behrang
• Assistant Examiner(s): Testardi, David A
• Application Number:
  US15/132,183
• Publication Number:
  US 20160303485A1
• Time in Patent Office: 764 Days
• CPC Class Codes: A63H 17/36 Steering-mechanisms for toy vehicles
• CPC Class Codes: A63H 17/395 steered by program
• CPC Class Codes: A63H 30/00 Remote-control arrangements specially adapted for toys, e.g. for toy vehicles steering mechanisms for toy vehicles A63H17/36; for model railways A63H19/24, A63H19/28
• CPC Class Codes: A63H 30/04 using wireless transmission
• CPC Class Codes: B62D 15/025 Active steering aids, e.g. helping the driver by actively influencing the steering system after environment evaluation B62D1/28 takes precedence
• CPC Class Codes: B62D 6/003 in order to control vehicle yaw movement, i.e. around a vertical axis B62D6/007 takes precedence
• CPC Class Codes: G05D 1/0011 associated with a remote control arrangement
• CPC Class Codes: G07C 5/008 communicating information to a remotely located station transmission systems for measured values G08C

Abstract

An electronic system for stabilizing steering of a model vehicle may provide a curvature steering control of an RC vehicle. The approximate curvature control of the RC vehicle determined using error integration to achieve full steering. Application of a leaky integrator may be used to minimize steering memory. The leak factor may be based off gain scheduling of the steering input.

Claims

1. An electronic system for stabilizing a steering of an RC model vehicle, the electronic system comprising:

a signal generator for generating a commanded curvature corresponding to a user steering command input via a user input interface;

a rate gyro sensor comprising a 6-axis MEMS device for sensing a measured rotation rate of the RC model vehicle;

an electronic feedback generator for generating a measured curvature corresponding to the measured rotation rate;

an electronic adder for generating a curvature error as a function of the commanded curvature and the measured curvature;

a proportional-integral-differential (PID) controller, wherein the PID controller produces a correction signal corresponding to the curvature error; and

a steering servo provided in the RC model vehicle and controlled corresponding to the correction signal.

2. The electronic system of claim 1, wherein the electronic feedback generator calculates the measured curvature with an estimated RC model vehicle speed.

3. The electronic system of claim 1, further comprising:

a linear accelerometer sensor; and

wherein the electronic feedback generator calculates an estimated RC model vehicle speed based on measurements from the linear accelerometer sensor, the measured curvature is calculated from the estimated RC model vehicle speed.

4. The electronic system of claim 3, wherein the estimated RC model vehicle speed is calculated via an extended Kalman Filter.

5. The electronic system of claim 1, wherein an integral term of the PID controller is further subjected to an anti-windup function in order to produce the correction signal.

6. A method for stabilizing a steering of an RC model vehicle, the method comprising:

generating a commanded curvature corresponding to a user steering command input via a user input interface;

measuring a rotation rate of the RC model vehicle via a rate gyro sensor comprising a 6-axis MEMS device;

generating a measured curvature corresponding to the measured rotation rate;

generating a curvature error as a function of the commanded curvature and the measured curvature;

generating a correction signal corresponding to the curvature error via a proportional-integral-differential controller;

controlling a steering servo in the RC model vehicle corresponding to the correction signal.

7. The method of claim 6, wherein the measured curvature is determined from the estimated RC model vehicle speed.

8. The method of claim 7, further comprising:

measuring linear acceleration of the RC model vehicle;

wherein the estimated RC model vehicle speed is calculated based upon the measured linear acceleration and the measured rotation of the RC model vehicle.

9. The method of claim 8, wherein the linear acceleration is measured with the 6-axis MEMS device.

10. The method of claim 8, wherein the estimated RC model vehicle speed is calculated via an extended Kalman Filter.

11. An electronic system for stabilizing a steering of an RC model vehicle, the electronic system comprising:

a rate gyro sensor for sensing a measured rotation rate of the RC model vehicle;

an electronic feedback generator for generating a measured curvature corresponding to the measured rotation rate;

an electronic adder for generating a curvature error as a function of a commanded curvature received by the RC model vehicle and the measured curvature;

a proportional-integral-differential (PID) controller comprising an error integrator function and an anti-windup function, wherein the PID controller produces a correction signal corresponding to the curvature error by processing an integral term of the PID controller by the error integrator function and the anti-windup function in order to produce the correction signal; and

a steering servo controlled corresponding to the correction signal.

12. The electronic system of claim 11, wherein the electronic feedback generator calculates the measured curvature with an estimated RC model vehicle speed.

13. The electronic system of claim 11, further comprising:

a linear accelerometer sensor; and

wherein the electronic feedback generator calculates an estimated RC model vehicle speed based on measurements from the linear accelerometer sensor, the measured curvature is calculated from the estimated RC model vehicle speed.

14. The electronic system of claim 13, wherein the estimated RC model vehicle speed is calculated via an extended Kalman Filter.

15. The method of claim 13, wherein the linear acceleration sensor is a 6-axis MEMS device.

16. The method of claim 11, wherein the rate gyro sensor is a 6-axis MEMS device.