EFFECT OF SENSOR ERRORS ON AUTONOMOUS STEERING CONTROL AND APPLICATION OF SENSOR FUSION FOR ROBUST NAVIGATION

Autonomous steering control is one the most important features in autonomous vehicle navigation. The nature and tuning of the controller decides how well the vehicle follows a defined trajectory. A poorly tuned controller can cause the vehicle to oversteer or understeer at turns leading to deviation from a defined path. However, controller performance also depends on the state–feedback system. If the states used for controller input are noisy or has bias / systematic error, the navigation performance of the vehicle is affected irrespective of the control law and controller tuning. In this report, autonomous steering controller analysis is done for different kinds of sensor errors and the application of sensor fusion using Kalman Filters is discussed. Model-in-the-loop (MIL) simulation provides an efficient way for developing and performing controller analysis and implementing various fusion algorithms. Matlab/Simulink was used for this Model Based Development. Firstly, through experimentation the path tracking performance of the controller was analyzed followed by data collection for sensor, actuator and vehicle modelling. Then, the plant, actuator and controllers were modelled followed by the comparison of the results for ideal and non-ideal sensors. After analyzing the effects of sensor error on controller and vehicle performance, a solution was proposed using 1D-Kalman Filter (KF) based sensor fusion technique. It is seen that the waypoint tracking under 1D condition is improved to centimeter level and the steering response is also smoothened due to less noisy vehicle heading estimation