Research On Vehicle Cruise Control System For ACC

Along with the austere situations of the traffic, people require moreand more safety in driving vehicles. ACC means Adaptive Cruise Controland an ACC system combines the Cruise Control System and the Safetydistance keeping system. So not only does it have the capability of cruisebut also the safety distance keeping ability. It makes driving safer.There're two factors influence the cruise control effect of the ACCsystem. The first is the innate nonlinearity of vehicle such as enginecharacteristic, which results in the variety of vehicle's state parameterswhen it is moving. Another is the change of circumstances such as thevariety of gradient, which interferes the control of vehicle's movement.The present control methods can hardly ensure a satisfied controlperformance to the above factors. A novel method that combines theRecursive Least Squares Method and Generalized Least Square Errormethod is proposed in this thesis and a cruise controller is developedaccording to the method. The controller has obtained good control effectwhen vehicle's parameters and the circumstances change.The inverse model approach method is used for establishing anapproximate linear system for the movement of vehicle and the CARMA(controlled autoregressive moving average) model is used for describingthe dynamics model of vehicle. Based on this, the input and output dataof the controlled object is sampled in the real time case. An identifier isdeveloped based on the Least Squares Error Method to get the CARMAmodel's parameters that express the real vehicle's characters. And anoblivion factor is used for preventing the saturation of the data. Thensome results of simulation experiments are given.Based on the above works, the Generalized Least Square Errormethod is proposed. It uses the difference of the weight of threeparameters, real acceleration, expectant acceleration and control value, asthe target function. So we can implement the speed control by minimizingthe target function finally. In other words, the control process to speed is achieved on the trail of the expectant acceleration. In the last, for ensuringthe control stability and the automobile ride, the reference track method isused for adjusting the expectant acceleration. The results of simulationexperiments indicate the efficiency of the control method.Furthermore, to validate the effectiveness of the proposed method,some experiments have been done on a testing vehicle platform improvedfor some intelligent functions. Some refit works are done for promotingthe information share ability of the testing vehicle platform. Then thedeveloped cruise controller is validated by the experiments on the testingvehicle platform under various running and environment conditions. Theresults indicate that the controller has good control performance.The research results of the thesis gives an effective way forimplementing the cruise control in the Adaptive Cruise Control systemwhen there are incertitude situations on the vehicle condition and runningenvironment.