Design And Development Of Vehicle Control Unit Of EV Based-on Mototron

With dwindling of non-renewable fuels such as oil, environment problem beingincreasingly serious, new energy vehicles which can realize low pollution, low energyconsumption get more and more attention all over the world. The governments in the majordeveloped countries such as Japan, Europe and the United States introduced a large numberof policies to promote the development of electric vehicles. Large international automobileenterprises also actively carried out the research for electric vehicles and launched advancedelectric vehicle products such as Pruis, Volt and Leaf. It is generally believed that the threekey technologies of the electric cars’ study are battery, motor and electronic control system.And from the angle of the vehicle research and development, the electronic control system isthe critical factor which achieves normal and efficient operation of electric vehice. Theelectronic control work of electric vehicle is mainly completed by VCU(Vehicle ControlUnit). VCU which is independent of the traditional underlying controller such as the motorcontroller, battery controller and ABS controller is responsible for coordinating the mainunderlying part to work and ensure that the vehicle system operates safely and reliably. Fortypical applications of pure electric cars, this paper carried out the hardware match and thesoftware design based on rapid prototype development platform Mototron. The researchwork of this article is mainly divided into the following four aspects:(1)Design of the overall scheme of VCU: according to the selection of vehicle modeland selection of main components, the vehicle control architecture of VCU was determined.On the basis of this architecture, this article maked the technical indicators of sensor signalsacquisition, actuators drive, communications clear ulteriorly. Synthetically considering theexpansibility and the diversity of requirements, the Mototron hardware selection wasdetermined and the functionality definitions of related pins were completed. Based onautomobile electronic software development model V process, the Mototron software designscheme based on model ws determined.(2)Research for the vehicle control strategy: respectively for different levels of thefunctional requirements of the vehicle, this paper studied and designed the correspondingcontrol strategy. In vehicle scheduling function level, the division and jump mechanism ofthe main operation modes of pure electric vehicle is studied in this paper; in torque controllevel, the regeneration control strategy and analytical methods of the driver torque demand.In the vehicle security level, besides designing the security mechanisms about correspondingfault park and limp home, also according to the characteristics of the pure electric vehicles,this paper designed the high voltage safety management strategy. (3)Devlopment of VCU software based on the Mototron: for the sensor signalconditioning, actuator drive and communication demands, the design of the underlyingfunction modules of VCU was completed by using the basic underlying hardware modulesprovided by Mototron. By applying the state machine function of SIMULINK, this paperrealized the scheduling control of the vehicle state. Combined with some factors such as theaccelerator pedal opening, brake pedal opening, SOC of battery, the parsing algorithm oftorque requirement was designed.(4)The VCU was validated on the basis of hardware in loop: VCU of pure electricvehicle developed based on Mototron was connected to the electric vehicle simulatordeveloped by research group. And the vehicle control strategy in this paper was validated bymaking the VCU operate under different modes through the working condition given andman-machine interface manipulation. Main validation contents include: the vehicle state andstate jump traversal, parsing driver’s demand under different cases, energy regenerationstrategy and other functions. Validation results show that the VCU of pure electric vehicledeveloped in this paper implemented the main functions such as vehicle driving, braking andsafe management and can be applied to real vehicle tests in the future In order to improve thehardware and software performance and make the work of this paper to be applied in realvehicles.