Control of an omnidirectional vehicle with multiple modular steerable drive wheels

摘要

This paper presents a method for controlling an omnidirectional vehicle with multiple modular steerable drive wheels. Each wheel module has two independent drive wheels and a two-degree-of-freedom (2DOf) attachment consisting of an activeprismatic joint and a free rotary joint. The attachment enables the wheel module under nonholonomic constraint to move the chassis better omnidirectionally. A controller consisting of vehicle-level and wheel-module controllers is designed to coordinatewheel modules to ensure correct vehicle movement. The vehicle-level controller determines the desired acceleration of the vehicle chassis to track its reference path, and each wheel-module controller controls its own actuator movement to generate thedesired acceleration. If the prismatic joint on the wheel module approaches its mechanical limit, the vehicle4evel controller corrects the acceleration to keep the joint position within the workspace. Simulation of a vehicle with four wheel modulesconfirmed the effectiveness of the proposed control.