Study And Design Of DCU Based On Motor Current Detection Method

The demand of passenger cars for DCU is increasing year by year with the rapid development of automotive electronics industry.DCU is a door control module which can realize four-door windows electric lifting,ripple anti-pinch and communication with BCM through CAN bus.However,the anti-pinch function may fail during use and cause occupant safety accidents due to the interference of complex external factors and the influence of its own software and hardware design.Therefore,higher standards and requirements are put forward for the existing DCU’s anti-pinch function by the automotive industry.Aiming at the stability and reliability problems of the DCU’s anti-pinch function,detailed research and design are carried out in this thesis,including DCU system design,hardware design,anti-pinch algorithm design,etc.More complete design ideas and methods are put forward.And the function and performance of the DCU are tested.Through analysis of the composition of the DCU system,the mechanical structure of the window and the structure of the ripple motor,the mathematical model of the ripple motor and the entire window system are established in this thesis.The relationship between the external clamping force received by the window and the motor current,the number of ripples and the travel of the window glass are verified.An anti-pinch scheme based on motor current detection is presented.For the design of system hardware,combined with the functional requirements of DCU system,the design of hardware schematic diagram including minimum system,low Dropout Regulator module,key input module,motor drive module,motor current processing module and CAN communication module are completed.For the design of system software,the external environment and the influence of the mechanical structure of the door and the ripple motor on the anti-clip function were considered,the ripple detection algorithm and anti-clip algorithm are designed,and the two algorithms are combined to achieve the anti-clip function.The adaptive strategy of anti pinch parameters,as well as the design strategy of window lifting function limitation,thermal protection and soft stop are also proposed in this thesis.Based on the analysis of CAN network,the communication function between DCU and BCM is realized through CANOE software simulation,and the test of related parameters are completed.In terms of anti-pinch function and performance,combined with the analysis of national standards and automotive testing requirements,the tests are carried out under static condition.The test results show that the anti-pinch function can be implemented normally,and the static anti-pinch force basically fluctuates around80±10N,which meets the design requirements.The stability and reliability of the ripple detection algorithm and the anti-pinch algorithm are verified.