Electric vehicle is a complex system composed of several subsystems, mainly including battery, motor, gearbox, braking and other power system, and other accessories such as air conditioning, anti-lock system. Almost all subsystems complete their respective functions and objectives through their own control unit (ECU). In order to meet the objectives of vehicle power, economy, safety and comfort, on the one hand, intelligent human-vehicle interaction interface must be provided; on the other hand, each system must cooperate with each other to optimize and match. Therefore, the electric vehicle needs a whole vehicle controller to manage the various parts in the pure electric vehicle.
Electric vehicle is a distributed power system control network based on CAN bus with the vehicle controller as the main node. Through this network, the vehicle controller CAN manage, coordinate and monitor each link of the power chain of pure electric vehicle, improve the energy utilization efficiency of the vehicle, and ensure the safety and reliability of the vehicle. The functions of the vehicle control unit (VCU) are as follows:
A. Start and stop the vehicle, the vehicle’s weak and strong up and down electric control;
B. Vehicle driving: collect the driver’s action information, analyze the driving intention, and manage the vehicle’s power output;
C. Network management: monitoring communication network, information scheduling, information summary, gateway;
D. Instrument communication: display necessary vehicle information and fault information;
E. Energy management: through the integration of vehicle information, battery and motor information to allocate power reasonably, the vehicle’s drive power output and braking energy feedback control, in order to obtain the best energy utilization;
F. Auxiliary parts management: coordination and management of auxiliary parts of electric vehicles (such as air conditioner, electric pump, etc.);
G. Fault diagnosis treatment: diagnose faults of sensors, actuators and other parts of the system and conduct corresponding fault treatment.