Modeling and Control of an Automotive Driveline

Abstract

In this research work LQG (Linear-Quadratic-Gaussian) and PID based control design for drive line of Electric vehicle is presented. People are more interested in Electric vehicles due to their high performance and economy in running cost. Electric vehicle is considered as a solution for energy and environment problems. Modern vehicles need a high degree of refinement to meet customer demand. With recent research in automotive electronics it is possible to electronically control a vehicle drive line. Driveline oscillations is a phenomenon of fluctuating vehicle speed caused by torsional vibrations in the vehicle drive line which results as jerks in the vehicle motion. These oscillations result in uncomfortable vehicle ride which is contemporary research problem. The control objective is to achieve steady state driveline in lesser time for this purpose LQG based control is pursued with certain modification in vehicle dynamic model. LQG is combination of kalman filter and linear quadratic regulator (LQR). Klaman filter estimate system states as it is not possible to measure all states of system using expensive sensors and LQR regulates torque demand to electric motor. In this research based project, we have also designed torque management strategies using a proportional–integral–derivative (PID) controller for traction and cruise control applications, to damp out driveline oscillations actively, and to improve drivability of EVs considering backlash as disturbance. Backlash is introduced in to the system to study the effect of nonlinearity in system. A model-based design approach has been adopted in this research since it can be used effectively for designing, developing and prototyping of controllers. This project includes driveline modeling, control design and verification by simulations. Results of simulation show the considerable mitigation of oscillations. LQG and PID based control for driveline of electric vehicle works very well