SAMPLED DATA ADAPTIVE CONTROL OF ELASTIC SYSTEM WITH BACKLASH

Abstract

The main focus of this thesis is, design of an adaptive controller to control the speed of an elastic system with Backlash such as Automotive Powertrain using sampled data techniques. Backlash occurs in mechanical transmission links due to the clearance gap in gears, when the driving gear is not exactly connected with the driven gear. It causes problem in drivability of the vehicles and also motion lost during the braking, acceleration and deceleration phenomenon. Lot of techniques is present in literature to tackle the problem of backlash in transmission links. This thesis deals with two techniques. First one is the model-reference-adaptive-control (MRAS) also known as model-reference-adaptive-system and the second one is self tuning regulator. Automotive Powertrain will be used in this thesis for implementation of the Elastic System with Backlash. The Automotive Powertrain model used as the elastic system with backlash is a nonlinear model that swings between two linear modes, the backlash-mode and the contact-mode. When the driving gears are exactly connected to the driven gears, the system is in Contact-mode and whenever the driving gears are not exactly connected to the driven gears, the system is in Backlash-mode. In model reference adaptive control system two separate MRAS controllers and two reference models for the respective Contact and Backlash modes will be used. In Self Tuning Regulator the parameters of the system will be estimated through switched Kalman Filter and using these estimated states a state feedback controller will be developed to control the speed of Automotive Powertrain. At the end Sampled-Data-System techniques will be used for Digital implementation of above said controllers.