Research Of Vehicle Semi-active Suspension Controller Based On DSP

With the incessant development of the vehicle structure and its function, studing the vehicle vibration and designing a new electronic control system to make the vehicle vibration at the lowest level have already become an important measure which raises modern vehicle quality. Because of the advantage of semi-active suspension itself, whose performance is higher compare with price. It must take the lead of suspension development in the future. Do research on adjustable damping shock absorber with credible performance and convenient adjustment, control strategy which calculate way is simple and useful, will make semi-active suspension accepted by the public.According to the dynamic request of vehicle run, Semi-active suspension improves its performance by changing choke area or regulating throttle opening to accommodate shock absorber damping. Adjust damping modulus measure is used a lot. Recently, with the development of the electronic technique,computer control technique and modern control theory, researchs on superior control,orientation control,fuzzy control,artificial nerve network control of vehicle suspension have gained not only great achievement on theory, but also be applied to the manufacture in practice. In our country, fuzzy control theory studying started since 1979,it is a intelligent control method which can imitate mankind's thinking. Its control method is simple, not need to build up complicated mathemactic models and use language variable instead of digital variable. Its control process consists of person's various relative control experiences and knowledges. The merit of fuzzy control is suit for vehicle suspension system control with different road, different velocity and various complicated work conditons.Because DSP operates quickly, and its inside resources are abundant, semi-active suspension controller based on DSP has high control accuracy, quick system response, it can fit more complicated control arithmetic and realtime control request, and with cheap price. Therefore, the system adopts fuzzy control strategy which outputs can feedback, and adopts high property DSP processor. Not only can they satisfy with the request for accuracy and speed of the semi-active suspension control, but also can make control regulation simple, and decline the cost.Semi-active suspension controller introduced in the paper, can evidently improve smooth and manipulable stability of vehicle, thus it raises driver's comfort. The ECU of controller adopts TMS320X digital signal processor(DSP) which made by American Texas Instruments company(TI). Semi-active suspension control system based on DSP well made use of DSP's features that it has rich peripheral interfaces, quick calculation rate. These merits make the system hardware design simple, system structure tight, and they have good dynamic and static characteristics. Control arithmetic adopt fuzzy control, which can make the control more effective, and decline its cost.In the paper, author simply introduces the work principle of semi-active suspension control system, describes different function modules consisted of the system, and builds up system dynamic module, gets appearance space models of controlled objects. It also elaborates the hardware and software design of the controller. The main points in the article is the built up of suspension control emulation model, designing for hardware circuit of DSP controller and fuzzy control programming.There are several contents in the paper:(1)Look back to the development of semi-active suspension , introduce the product in and out of the nation to make a comparison, and carry on sum-up to generalize the domestic and international academic research result.(2)Through analyzing the structure of semi-active suspension, establish and emulate the dynamic models, in the meantime, carry on a research to the control arithmetic for the DSP suspension controller.(3)Design and create the controller based on DSP, draw principle and pcb diagrams, joint the circuit board, and debug it primarily.(4)Go along with modularization design for relative softwares, carry on a analysis of the diagram dependability, and a verification to the arithmetic validity.(5)Analyze the results in experiment, then do some appropriate modify and improvement to the system. sum up to the research process, and give a conclusion.