In the combined mode, the sensors emit a series of ultrasonic pulses and then switch to the mode of receiving sound reflected from an obstacle within the radius of action. The received reflected signals are amplified and converted from analog to digital form in the sensor itself. The digital signal passes to the parking assistance module and is compared with the programmed data located in the module's EEPROM. The control module receives this data from the sensor via the signal transmission line and calculates the distance to the obstacle based on the time interval between the irradiation of the obstacle and the reception of the reflected signal. The pulse duration is determined by the module, which, using the sensor, controls the frequency of the output pulse.
In receiver mode, the sensor receives pulses emitted by neighboring sensors. The control module uses this information to accurately determine the position and distance to the obstacle.
If no obstacles are detected, no additional warning signals are emitted. If an obstacle is detected, repeated acoustic signals are emitted from the corresponding front or rear speakers. The interval between the signals decreases as the distance between the obstacle and the vehicle decreases. At a distance of approximately 250 mm, the acoustic signal becomes continuous.
If after the initial detection of an obstacle the distance between it and the vehicle does not decrease, the nature of the warning signal remains unchanged if the obstacle is detected by the central sensor, or the signal stops sounding after 3 seconds if the obstacle is detected by the corner sensor.
The audible signals stop when the vehicle is moved out of reverse gear. The module continues to monitor the distance and resumes the warning signals if a decrease in distance is detected.
The system is cancelled when the parking assist switch is pressed or the ignition is turned off. The system is also cancelled if the vehicle moves more than 50 m or the vehicle's forward speed exceeds 30 km/h.
The system can detect the connection of a trailer to the vehicle via a medium-speed CAN bus message from the trailer module. When the parking assistance module detects that a trailer is connected to the vehicle, the rear sensors are disabled to prevent continuous warnings due to the proximity of a trailer.
The parking assistance module also contains software that compensates for the effects of frost, ice or rain on the sensors. Ice compensation occurs if the outside temperature value received in the medium-speed CAN bus message from the instrument cluster is less than 6°C.
Distance calculation
NOTE: A = Intermittent warning sound; B = Continuous beep
The maximum detection range for front sensors is 800 mm for center sensors and 600 mm for corner sensors.
The maximum detection range for rear sensors is 1800 mm for center sensors and 600 mm for corner sensors.
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