PDC sensor for autonomous parking
PDC sensors are essential components of Autonomous Parking Assist (APA) systems, enabling vehicles to park themselves without human intervention. In automatic parking scenarios, multiple ultrasonic radars are arranged around the vehicle to detect parking spaces and obstacles. This guide covers the application of PDC sensors in autonomous parking, system architecture, and working modes.
PDC sensors are essential components of Autonomous Parking Assist (APA) systems, which represent a significant advancement in modern automotive intelligent driving technology. The Automatic Parking Assistance (APA) system is an essential component of modern automotive intelligent driving technology, enabling vehicles to complete the parking process automatically without any human intervention. Specifically, the APA system detects available parking spaces and obstacles through sensors (surround-view cameras, ultrasonic radars, etc.) placed around the vehicle, then plans the parking path and controls vehicle movement to complete the parking process. In the automatic parking scenario, 12 ultrasonic radars are generally arranged around the vehicle to complete the fully automatic parking function. The ultrasonic sensors on the front and rear of the vehicle calculate the position of potential obstacles, with an intermittent tone indicating how much space is still available.
PDC Sensor
Ultrasonic radar used in APA automatic parking is divided into two main types. One type is short-range radar installed in the front and rear bumpers for detecting obstacles, with a detection range of 15-250 cm. This type of sensor is called a PDC sensor. The other type is installed on the sides of the vehicle to detect the length of parking spaces, with a detection range of 30-500 cm. This type of sensor is called a PLA sensor. The location of PDC and PLA sensors is strategically arranged around the vehicle to provide comprehensive coverage for autonomous parking. Compared to millimeter-wave radar or other types of radars, ultrasonic radar has many advantages, such as low manufacturing cost, easy installation, and easy maintenance.
In practical automatic parking scenarios, ultrasonic radar has various working modes. In the Direct Echoes working mode, the ultrasonic radar can calculate the distance between the vehicle and obstacles through the time of flight (TOF) of the sound waves. This mode is relatively simple in principle but cannot obtain the two-dimensional coordinates of obstacles, i.e., it cannot determine the spatial position of obstacles relative to the vehicle. The Cross Echoes working mode uses multiple ultrasonic radars as receivers of sound waves, allowing for better acquisition of the spatial position of obstacles relative to the vehicle, but the calculations are more complex. During parking, the ultrasonic radar can calculate and output the distance between the vehicle and surrounding obstacles in real-time. The controller software processes the ultrasonic data to fit the contours, shapes, and relative positions of surrounding obstacles.
The APA automatic parking process follows a specific sequence. In a horizontal parking scenario, the driver activates the vehicle's APA automatic parking function, and the vehicle moves forward at low speed. Combining the ultrasonic perception data, the APA system identifies a suitable parking space. After enabling the function, the vehicle proceeds to the next steps of path planning, vehicle control, etc., until the vehicle successfully parks and exits the APA automatic parking function. The entire APA automatic parking process involves speed control modules, direction control modules, gear position control modules, and path planning. Important parameters for ultrasonic radar include measurement range (maximum detection distance), FOV (Field of View - horizontal and vertical viewing angles), and radar working frequency (typically around 40 kHz).
The benefits of PDC sensors for autonomous parking are significant for the future of mobility. Ultrasonic sensors facilitate driving in and out of the most confined parking spaces. The sensors calculate the position of potential obstacles, with an intermittent tone indicating how much space is still available. The system is capable of real-time data processing, feeding signals into control systems for autonomous vehicle operation. As autonomous parking technology continues to evolve, PDC sensors are becoming increasingly sophisticated with improved detection accuracy and range. The ongoing development of sensor technology and signal processing will further enhance the performance and reliability of autonomous parking systems. Understanding the role of PDC sensors in autonomous parking helps drivers appreciate the technology that enables self-parking vehicles.
