Anti Jerk Control Of Hybrid Electric Vehicle Engineering Essay

Anti Jerk Control Of Hybrid Electric Vehicle Engineering Essay The report details the review done in the area of anti-jerk control of vehicles. It explains the phenomenon of driveline oscillations excited due to torsion of driveline at high engine torques causing unwanted longitudinal oscillations in vehicle body. Report starts with a broad introduction to the topic and lays down the aims and objectives of the research project. The aims and objectives of the project are to design an active feedback control for an electric motor of a hybrid electric vehicle to damp these undesirable oscillations. A summary review of previous research work done in this area is presented which defines the starting point of the project. Different techniques used for anti-jerk control in conventional vehicle are discussed. Basic approach to model based control design is presented in the report. An introduction to hybrid electric vehicle driveline and description of its components different from conventional vehicle is shown. The report also lays down the procedure o f the work to be followed for the research project with a project plan. INTRODUCTION The increasing pressure of protecting the natural environment and to decrease the dependence on non-renewable sources of energy has encouraged vehicle manufacturers to develop more clean and efficient power systems. As a result Hybrid vehicles are hot topic for research among vehicle manufacturers. Efforts are being made to make the vehicles more fuel efficient with high performance and minimum CO2 emissions. Diesel hybrids are considered as next big thing among ecological designs since diesel engines are 20 % – 30% more fuel efficient than their petrol counterparts. Nowadays noise, vibration and harshness (NVH) issues have become more important for a customer such that there are very stringent requirements for noise or vibration in a vehicle. Driveability of a vehicle is majorly impacted by NVH problems and is strongly felt as vehicle’s performance during various manoeuvres such as ac celeration, braking, gear change etc. Thus vehicle manufacturers and OEM’s have realized the importance of NVH issues and target to identify the root cause of vibration and incorporate the correcting measures at early stages of manufacturing with a main goal to refine the ride and driveability of a vehicle. These days’ efforts are being made to increase the performance of vehicles and to make them more fuel efficient by using different techniques and one of the techniques is electrification of various systems in a vehicle. Electronic power assist steering system, electric active roll control, electronic differential, brake by wire are some of the examples of electrification of vehicle systems. This kind of methodology becomes more evident in case of hybrid electric vehicles where electric power components including power electronics are integral part of the powertrain. It has been observed that using these electrification techniques not only helps in increasing the per formance of the vehicle but also makes them more fuel efficient. Thus the electrification in a diesel hybrid powertrain to improve the driveability of vehicle forms the main platform for this research project. Problem Statement One of the major NVH issues in automobiles is torsional vibrations of driveline. The torsion of drivetrain at high engine torques causes oscillations in driveline. These oscillations are generally excited by various sources such as rapid or sudden load/torque change, gear change and unevenness of road surface. These oscillations cause longitudinal acceleration in vehicle structure and passenger compartment of the vehicle, which reduces the comfort and driveability of the vehicle and are experienced as unwanted jerking by the driver and passengers. These type of driveline oscillations are termed as Jerking, which is the main focus of this research.