Research And Development Of The Hardware-in-the-Loop Test Bench For Steer-by-Wire System

Steering-By-Wire System (SBW), which is also called electric front wheel steering, cancels mechanical linkage between the steering wheel and front wheels, so it gets out of the restricting of traditional steering system and we can design the steering characteristic freely. It is a great renovation of steering system. Steering maneuver is detected through steering angle sensor and torque sensor. This information is transferred to a SBW controller, which use this sensor information and other sensor information to control the front wheels'angle and steering wheel torque. So there is no conflict between the desirable angular ratio and hand wheel torque. But as it is not so dependable as normal steering system and other power steering system, the hardwire-in-the-loop test bench is quite important during the research.The thesis focused on the building of the hardwire-in-the-loop test bench for the steer-by-wire system. The following is mainly content in the thesis: Chapter one included development of the steer-by-wire system, and pointed out the meaning to research the system. Then it introduced the configuration, principle, characteristic and the key technology of steer-by-wire system. Chapter two analysised the performance of the steer-by-wire system, and intrduced the development of the test bench in the world and some basical functions of the test bench. Then, based on this, some schemes of the test bench were showed, contrasted with each other, and finilly the magnetic partical brake system was determined to be chossen considered to the realistic situation. After that, the principle of the test bench was introduced, as well as the programming and the configuration of the whole test bench.Chapter three is the hardware of our test bench. It was devided in to two parts: the loading resistance system and the steering reactive torque system. Both their configuration, function and principle were introduced. In order to get the right type of the parts, some requests were pointed out and some market researches were made for them, and all of the parts were determined according to the price, performance and our realistic situation. At last, the signal transmission system and control system was introduced.Chapter four is the software of our test bench. The first thing is about the mathetic models of the system. According to the need on the test bench, some necessary models were built, and all of the models, including the steering system models and the full-car model, were introduced during this chapter. After that, the research environment and system parameters were set up.Chapter five did the experiments. The experiments were mainly about the magnetic partical brake system. First, the experiment detected the mathetic connection between the loading torque and the control voltage; second, different voltage was given to see if the loading torque was just the torque we need. Based on this, some dynamic experiments have been done for the loading system and analyzed its performance. The results showed the magnetic partical brake can be charged with the task of loading resistance to the system.The last chapter was about the summarization to the thesis as well as the shortcomings and lacks in the thesis, and the foundation for the comming tasks was also made during this chapter.