Research And Development Of Control System For Hybrid Electric Vehicle Powertrain

Powertrain Control System is a key technology of hybrid electronic vehicle. Despite extensive literature exploiting hybrid energy management, the four-wheel-drive hybrid powertrain energy management study was few. In addition, the existing literature on quality control is only related to the coordination control of powers. Faced to such a challengeable control problem, the dissertation successfully accomplishes the entire research process, from concept analysis to algorithm development, from simulation to the prototype vehicle testing in order to fix the problem.It is the first time that the four-wheel drive hybrid powertrain control system was divided into energy control and control quality by the present dissertation. The energy control is how to decide all parts working states and their parameters, while control quality is how to coordinate operation between power sources and automatic transmission and to control hydraulic system for automatic transmission.First, the hybrid powertrain system model was built according to the static parts' efficient MAP by a new hybrid modeling method, which combined backward modeling and forward modeling method. In the process the present dissertation proposed standard interfaces of the parts' model which may make simulating software portable and expansible.Secondly, the deep investigation of energy management about the multi-power train system was carried on in its output characteristic field and a kind of energy management method was designed in term of the whole powertrain efficiency. And the energy management was proved to be feasible and available by computer simulation.Thirdly, the present dissertation studied powertrain system control quality and works out the corresponding algorithms which can avoid the cycles of powertrain working modes and shift switch and finish dynamic coordination and limit stalls shift process control. The dissertation also analyzes hydraulic control unit of automatic transmission to make the hybrid power-train system work correctly.The present dissertation also examines the powertrain components' function and analyzes the logical relations between different controllers and designs functional interfaces of vehicle controller and automatic transmission controller. Based on the CAN bus protocol principle, the hybrid electronic vehicle bus application layer has been designed for the HEV control strategy and in light of the studies of the hybrid powertrain working process, the powertrain system was divided into four layers described detail by state graph.Finally this dissertation developed vehicle controller and AT controller according to the above results. The hardware circuit was designed through the use of relative measurement principle and module design method to improve its ability of anti-jamming and the system software was developed through the use of database-base software architecture in order to make it portable and running efficiently.After accomplishing all the work, the car equipped with the controller was debugged and on-road tested. During the test, the car speed changed steadily and had low impulsion. It can be concluded that the control system has achieved the expected function.