Dynamic Modelling for the Path Tracking Control of a Four-Wheel Independent-Drive, Four-Wheel Independent-Steer Autonomous Ground Vehicle
Abstract
Robots that can be reconfigured to perform more than one task would be to consumers. The Four-Wheel Independent-Drive, Four-Wheel Independent-Steer (4WD4WS) robot is well suited for the role of reconfigurable robot due to its extremely high maneuverability and torque control. However, the nonlinear dynamics in conjunction with complex kinematic constraints make the 4WD4WS structure an extremely difficult control problem. As a result of this many who model the 4WD4WS structure make simplifications that aren’t realistic for a reconfigurable consumer robot. A 4WD4WS robot is kinematically and dynamically modeled using both the front and rear path angles and their respective coordinates. High fidelity equations of motion, for robots of arbitrary width, length, and mass, undergoing arbitrary accelerations at arbitrary steering angles have been created that have the potential to increase the path tracking ability of 4WD4WS systems. Simulations show the model behaves realistically, but needs a controller.