Method of joint planning and control of a rigid, separable non-holonomic mobile robot using a harmonic potential field approach

• US 9,098,079 B2
• Filed: 12/13/2013
• Issued: 08/04/2015
• Est. Priority Date: 12/13/2013
• Status: Active Grant

• Current Assignee: King Fahd University Of Petroleum And Minerals
• Original Assignee: King Fahd University Of Petroleum And Minerals
• Inventors: Masoud, Ahmad A.
• Primary Examiner(s): Jen, Ian
• Application Number:
  US14/106,040
• Publication Number:
  US 20150168939A1
• Time in Patent Office: 599 Days
• Field of Search: 700/245
• US Class Current: 1/1
• CPC Class Codes: G05B 2219/40298 Manipulator on vehicle, wheels, mobile
• CPC Class Codes: G05B 2219/40476 Collision, planning for collision free path
• CPC Class Codes: G05D 1/0223 involving speed control of the vehicle vehicle fittings for automatically controlling, i.e. preventing speed from exceeding an arbitrarily established velocity or maintaining speed at a particular velocity, as selected by the vehicle operator B60K31/00
• CPC Class Codes: G05D 1/0274 using mapping information stored in a memory device navigation using map-matching G01C21/30
• CPC Class Codes: Y10S 901/01 Mobile robot
• CPC Class Codes: Y10S 901/46 Sensing device

Abstract

A method of joint planning and control of a rigid, separable non-holonomic mobile robot using a harmonic potential field approach is provided. A controller, including a processor and memory, may receive parameters of the robot and a plan having a reference velocity field vector. The controller calculates a synchronization signal and a control signal. The control signal is used to synchronize an actual velocity of the robot in order to navigate the robot according to the plan.

Claims

1. A method for controlling a position of a robot, the method comprising:

transferring a plan to a controller including a processor and memory, storing the plan in the memory, the plan including a reference velocity field vector;

transferring parameters of the robot to the memory of the controller, the parameters including kinematics of motion of the robot;

calculating, in the processor of the controller, a synchronization signal, S, based on the parameters of the robot;

calculating, in the processor of the controller, a control signal, U, based on the synchronization signal S; and

generating, in the processor of the controller, the control signal, U, to synchronize an actual velocity of the robot to navigate the robot according to the plan.

2. The method for controlling a position of the robot according to claim 1,

wherein the robot is a front wheel steered robot, and

wherein transferring parameters of the robot to the controller includes:

transferring, to the controller, a distance, L, between a front wheel of the robot and an axle of rear wheels of the robot,

transferring, to the controller, an angular speed, ω

_h, of the rear wheels of the robot, and

transferring, to the controller, a steering angle, φ

, of the front wheel of the robot.

3. The method for controlling a position of the robot according to claim 2, wherein kinematics of motion of the robot are described as:

4. The method for controlling a position of the robot according to claim 3, wherein the calculating is performed to determine the synchronization signal, S, by:

5. The method for controlling a position of the robot according to claim 4, wherein the calculating is performed to determine the control signal, U, by:

6. The method for controlling a position of the robot according to claim 1,

wherein the robot is a differential drive robot including at least two wheels, and

wherein transferring parameters of the robot to the controller includes:

transferring, to the controller, a radius, r, of the at least two wheels of the robot,

transferring, to the controller, an angular speed, ω

_L, of a first wheel of the at least two wheels,

transferring, to the controller, an angular speed, ω

_R, of a second wheel of the at least two wheels,

transferring, to the controller, a tangential velocity, v, of the robot, and

transferring, to the controller, an angular speed, ω

, of the robot.

7. The method for controlling a position of the robot according to claim 5, wherein kinematics of motion of the robot are described as:

8. The method for controlling a position of the robot according to claim 7, wherein the calculating is performed to determine the synchronization signal, S, by:

9. The method for controlling a position of the robot according to claim 8, wherein the calculating is performed to determine the control signal, U, by:

10. The method for controlling a position of the robot according to claim 1,

wherein the robot is a differential drive robot including at least two wheels, and

wherein transferring parameters of the robot to the controller includes:

transferring, to the controller, a mass, W, of the robot;

transferring, to the controller, a first torque, TL, applied to a left wheel of the at least two wheels; and

transferring, to the controller, a second torque, TR, applied to a right wheel of the at least two wheels.

11. The method for controlling a position of the robot according to claim 10, wherein a first actuation stage of motion is described as:

12. The method for controlling a position of the robot according to claim 11, wherein a second actuation stage of motion is described as:

13. The method for controlling a position of the robot according to claim 12,

wherein the calculating is performed to determine the synchronization signal, S, by:

14. The method for controlling a position of the robot according to claim 13,

wherein the calculating is performed to determine a damping force, S_D, by:

15. The method for controlling a position of the robot according to claim 14, wherein the calculating is performed to determine the control signal, U, by:

16. The method for controlling a position of the robot according to claim 1, wherein the control signal is a velocity synchronizing signal.

17. The method for controlling a position of the robot according to claim 1, wherein the control signal is a torque synchronizing signal.