Analysis of the Technical Architecture of Automotive Safety Systems
Dec 21, 2022 View: 263
With the continuous advancement of electronic technology and control science, automotive electronic systems have also undergone revolutionary changes. The safety protection system of the vehicle is also gradually upgraded from the traditional passive systems such as seat belts and airbags to active safety systems such as pre-collision control. And all of this is achieved thanks to a variety of sensors and their control systems for driving, braking, engine control, speed control, safety protection and other performance support.
1. Airbag Control System
First of all, take the airbag control system as an example. The system mainly consists of the airbag in front of the driver and passengers, the impact sensor (Satellite Sensor) located outside the body, the acceleration sensor (G-Sensor) placed in the door, seat and roof, and the ECU, which is usually a 16-bit or 32-bit MCU, and other components.
When the body is collided, the impact sensor will immediately send a signal to the ECU, and the ECU will collect the collision intensity, seat position, passenger weight, seat belt condition and other parameters to make a rapid assessment, and in a very short time through the electric explosion driver (Squib Driver) to open the airbag to protect the safety of the occupants.
2. Active Suspension System
Active Suspension (Active Suspension) is also a relatively common security system in the car, which can significantly improve the handling of the vehicle. Active suspension system mainly consists of sensors, shock absorbers and computer control system.
The system can collect the car's speed, acceleration, weight, steering degree, left and right G force and other data to be programmed to make real-time adjustments to the suspension coefficient, and the height of the chassis and the ground.
3. Anti-lock Braking System
More and more national laws and regulations are demanding the performance of Anti-lock Brake Systems (ABS), and the higher requirements for its reliability have increased the complexity and difficulty of ABS design and development. In the system shown in Figure 4, the main purpose of ABS is to prevent the dangerous situation of vehicle stalling and skidding.
When the control link finds that the emergency braking leads to low speed, it will quickly point and release the brakes, giving the tires enough rolling space and more grip to prevent the vehicle from running off the road. The key to this system is the measurement of tire speed.
4. Electronic Power-Assisted Steering Wheel
Electronic power assisted steering (EPAS) system, referred to as power steering. Compared with the traditional hydraulic steering wheel, EPAS uses an electronic motor to provide the driver with auxiliary control of wheel steering.
EPAS generally obtains the steering wheel position and torque from sensors, and then combines the vehicle speed, engine temperature, battery power supply and other parameters to realize the auxiliary control of the electronic motor. Improve the efficiency of fuel use.
5. Pre-tensioned Seat Belt System
Pre-tensioned seat belt (Seat Belt Tensioner) is also an advanced driving safety and security system, which can be used as a sub-system of the collision system. The pre-tensioned seat belt in the vehicle when normal driving to give the driver and passenger larger shoulder space, so that they can enjoy the comfort of driving and riding; But in the moment of accident, in order to protect the safety of personnel, to avoid its forward impact and body injury, pre-tensioned seat belt can be quickly tightened, so that personnel close to the seat, to reduce the risk of collision with objects in front of it.