Intehigent CAN-based automotive cohision avoidance warning system

To construct a vehicle collision avoidance system, a laser radar and three ultrasonic sensors are integrated with the CAN bus to build the in-car network architecture to prevent the car on all directions. There are two sub-systems developed for this collision avoidance system: (a) the front-end sub-system and (b) the side and rear-end sub-system. The front-end collision warning sub-system is constructed for high-speed driving conditions by measuring the distance in the front with a laser radar. Moreover, the relative speed between two cars can be properly estimated by applying the current Kalman filter. Then, a D/V curve is further obtained to generate collision warning with a desirable precaution time to prevent the front-end collision actively. For the collision avoidance on the side and the rear-end, the approaching speed from other cars in general is slow and available ultrasonic sensors with limited range and resolution are adopted. An intelligent approach is proposed to process the rough distance readout to render warning signals with suitable timing for the approaching car drivers to prevent the collision passively. A high-level network protocol CANopen is applied to integrate all ultrasonic sensors as the in-car network communication.