The Vehicle Cruise Control System With The Function Of Preventing Mistakenly Stepping On Accelerator Pedal

The vehicle cruise control system with the function of preventing mistakenly stepping on accelerator pedal is a new driving assistance system,it is a combination of cruise control system(CCS) and the anti-misstep-accelerator subsystem(AMAS).While the traditional cruise control function is maintained,the AMAS,based on CAN,with on-board diagnostic port(OBD) as a data feedback port,can eliminate or avoid traffic accidents which are caused by the drivers’ according to the signal of accelerator pedal, the turn light and other information. The new assistance system not only frees driver’s feet,but also ensures the safety of vehicles.A complete vehicle longitudinal dynamics model based on MATLAB/SIMULINK is established with the reasonable simplified initial condition by analyzing the research of current Cruise Control System, including one-order inert simplified engine model, the torque converter model,brake model,automatic transmission models and vehicle dynamics model.The automatic transmission position switch logic model is built by the theory of finite state machine(FSM) in MATLAB. The model accurately reflects the dynamic characteristics of vehicle dynamics system and systematically meets the demand for dynamics simulation.By comparing advantages and disadvantages of fuzzy PID control,PID control and iterative algorithms control,the paper proposes a general scheme based on the fuzzy PID control and establishes a fuzzy PID controller of CCS.The controller is simulated and analyzed combining the longitudinal dynamics model. The simulation results show that the control effect of fuzzy PID controller is better than normal PID controller; In order to ensure the stability and security of AMAS,the key technologies involved in the AMAS has been reasearched,a distinguishing method for AMAS based on competed artificial neural network is proposed, the paper mainly expounds upon methods principle of choosing neural network parameter,to establish a neural network ground on the throttle sensor signal and the change of the current amplitude within 46 millisecond as the working model.The MC9S12DP512 MPVE is seleceted as the microcontroller chip,the circuit of single-chip microcomputer minimum system,CAN transceiver circuit,input filter circuit and the digital to analog conversion circuit are designed;According to the proposed general plan,each module is initialized,the program design of each modules is developed and debugged,iucluding the acquisition of accelerator pedal signal,the transmission and reception of CAN messages,the output of PWM and the main-control module.The system functional simulation, semi-physical simulation and real vehicle integration test are competed successfully. The results showed that the system has good performances on CAN bus communication,the function of CCS and AMAS are stable and reliable,therefore the system design is reasonable and stable,it can assist the driver to drive and offers a safeguard for the drivers.