CONTROL OF VERTICAL MOTION OF AN AUTONOMOUS HEAVY VEHICLE USING MR DAMPER

Abstract

Nowadays, due to its widespread application in automobile, aerospace, railway, defense sector and other industries, suspension systems, automation and advances are gaining a lot of momentum. Researches on ensuring the safety and comfort of autonomous vehicles are currently of utmost importance and gaining lot of momentum. Reducing the likelihood of motion sickness amongst passengers inside autonomous vehicles has emerged as a crucial study area, serving as an evaluation criterion for vehicle comfort during driving. Active suspension system is more effective in achieving these, however it requires lots of power, it is not cost effective making it unsuitable. A more practical alternative is the use of semi-active suspension system. In this study, the vertical and longitudinal dynamics of Unmanned Ground Vehicle (UGV) are derived. The vertical vibrations are controlled a semi-active suspension system incorporating a MR damper with Skyhook and PID controller. The Modified Bouc-Wen Model is considered. The longitudinal motion of the UGV is controlled by a gain scheduled LQR with integral and compensation action. ISO 8608, ISO 8606 and ISO 2631 are used to identify the type of road by its roughness and to identify the correct speed for best comfort. The simulations are designed and performed on MATLAB SIMULINK. Various controllers for the vertical and longitudinal motion are designed and the most effective ones in each motion type are implemented together for a comfort based autonomous driving experience.