F2010E024
A Study on the Motion Control of 6x6 Electric Vehicle with Skid Steering. Part 1: Torque Control Algorithm for 6x6 Electric Vehicle with In-Wheel-Motors
The skid steered vehicles are favoured for military use in off road operations because of their high manoeuvrability and mobility on extreme terrains and obstacles. All the wheels in this case are non-steerable. The skid steered vehicles are turned by generating different longitudinal forces by the tires due to the application of different torques to wheels on opposite sides of the vehicle. This system is particularly simple to realize using the In-Wheel-Motors in which the torque can be independently controlled. The electric motors when utilized as In-Wheel-Motor, gives us the advantage of accurate torque generation very quickly with response time in several milliseconds. Moreover the motor torque can be easily known from motor current. The torque control algorithm in this study consists of two parts. The first parts is the Torque Distribution of driver torque command to all wheels based on the dynamic stability and handling parameters, such as steering angle, yaw rate and lateral acceleration. Based on these parameters, torque ratio for left/right wheels and front/middle and middle/rear wheels is designed dynamically. The second part deals with special focus on minor feedback control at each In-Wheel-Motor which will ensure that the commanded torque will not cause the wheel to slip in different road conditions. Controlling the slip ratio at each wheel will further enhance the dynamic stability by generating the optimum longitudinal forces. In this study we modelled the Skid Steering Six Wheeled Vehicle (6x6) using Simulink® and the proposed torque control algorithm is tested using the developed model for different manoeuvres. Key words: Skid Steering, Six Wheel Drive 6x6, In Wheel Motors, Torque Control Algorithm, Modelling and Simulation.
This abstract is supplemented by a PDF, which can be viewed here.