The main components of the vehicle control system are control system, body and chassis, vehicle power supply, battery management system, drive motor, safety protection system. The energy output, energy management, and energy recovery of traditional oil vehicles and new energy vehicles are different. . These are completed by the vehicle electronic control system.
The vehicle controller is the control center for the normal driving of electric vehicles , the core component of the vehicle control system, and the main control components for the normal driving of pure electric vehicles , regenerative braking energy recovery, fault diagnosis and processing, and vehicle status monitoring. So what are the functions of the new energy vehicle vehicle control system? Let’s take a look at the following.
1. The function of driving the car
The power motor of the new energy vehicle must output the driving or braking torque according to the driver’s intention. When the driver steps on the accelerator pedal or brake pedal, the power motor must output a certain driving power or regenerative braking power. The greater the pedal opening, the greater the output power of the power motor. Therefore, the vehicle controller should reasonably explain the driver’s operation; receive feedback information from the subsystems of the vehicle to provide decision-making feedback for the driver; and send control commands to the subsystems of the vehicle to achieve the normal driving of the vehicle.
2. Network management of the vehicle
In modern automobiles, there are many electronic control units and measuring instruments, and there is data exchange between them. How to make this data exchange fast, effective, and trouble-free transmission becomes a problem. In order to solve this problem, German BOSCH company in 20 The Controller Area Network (CAN) was developed in the 1980s. In electric vehicles, electronic control units are more and more complex than traditional fuel vehicles, so the application of CAN bus is imperative. The vehicle controller is one of the many controllers of electric vehicles and a node in the CAN bus. In vehicle network management, the vehicle controller is the center of information control, responsible for information organization and transmission, network status monitoring, network node management, and network fault diagnosis and processing.
3. Braking energy feedback control
New energy vehicles use electric motors as the output mechanism for driving torque. The electric motor has the performance of regenerative braking. At this time, the electric motor acts as a generator and uses the braking energy of the electric vehicle to generate electricity. At the same time, this energy is stored in the energy storage device. When the charging conditions are met, the energy is reversely charged to the power battery pack. In this process, the vehicle controller judges whether the braking energy feedback can be performed at a certain moment according to the opening of the accelerator pedal and the brake pedal and the SOC value of the power battery. The device sends a braking command to recover part of the energy.
4. Vehicle energy management and optimization
In a pure electric vehicle, the battery not only supplies power to the power motor, but also supplies power to the electric accessories. Therefore, in order to obtain the maximum driving range, the vehicle controller will be responsible for the energy management of the vehicle to improve the utilization rate of energy. When the SOC value of the battery is relatively low, the vehicle controller will send commands to some electric accessories to limit the output power of the electric accessories to increase the driving range.
5. Monitoring and display of vehicle status
The vehicle controller should detect the status of the vehicle in real time, and send the information of each subsystem to the vehicle information display system. The process is to detect the status of the vehicle and its subsystems through sensors and CAN bus, and drive the display instrument. , to display the status information and fault diagnosis information through the display instrument. The display contents include: motor speed, vehicle speed, battery power, fault information, etc.
6. Fault diagnosis and treatment
Continuously monitor the vehicle electronic control system for fault diagnosis. The fault indicator indicates the fault category and some fault codes. According to the fault content, timely carry out corresponding safety protection processing. For less serious faults, it is possible to drive at a low speed to a nearby maintenance station for maintenance.
7. External charging management
Realize the connection of charging, monitor the charging process, report the charging status, and end the charging.
8. Online diagnosis and offline detection of diagnostic equipment
It is responsible for the connection and diagnostic communication with external diagnostic equipment, and realizes UDS diagnostic services, including data stream reading, fault code reading and clearing, and debugging of control ports.
Post time: May-11-2022