Ala http://www.parkingdynamics.com
I found this information from the manufacturer but it's not very descriptive. Or maybe I'm just bad at comprehending it.
The Parking Dynamics PD1 is based on an innovative concept that uses electromagnetic waves with low energy.
When reverse gear is selected the small electronic control unit (ECU) generates an electromagnetic field and transfers this to the transceiver adhesive tape that is placed on the inner side of and run the length of your bumper. The PD1 Front sensor is activated by a a switch and works in exactly the same way as the PD1 rear reverse sensor.
The magnetic tape (antenna) then sends out an elliptical electromagnetic field to cover the full area around your bumper, front, rear and sides. The transceiver antenna tape works by sending and receiving unlike ultrasonic parking and reverse sensors that require 2 types of sensors, one to send and one to receive; if they become dirty the ultrasonic performance can deteriorate.
An obstacle is then monitored by the electronic control unit (ECU) by translating this obstacle measurement into a voltage. When an object with a certain mass (i.e. people, kerbs, cars, etc) enters this elliptical zone a change in the electrical field is created and an increase in voltage is detected by the control unit and you are then informed by a series of audible tones how close you are to the object. The PD1-Vision also gives you a visual alert with integrated audio. You can then manoeuvre accordingly with plenty of time to react.
When reverse gear is selected the small electronic control unit (ECU) generates an electromagnetic field and transfers this to the transceiver adhesive tape that is placed on the inner side of and run the length of your bumper. The PD1 Front sensor is activated by a a switch and works in exactly the same way as the PD1 rear reverse sensor.
The magnetic tape (antenna) then sends out an elliptical electromagnetic field to cover the full area around your bumper, front, rear and sides. The transceiver antenna tape works by sending and receiving unlike ultrasonic parking and reverse sensors that require 2 types of sensors, one to send and one to receive; if they become dirty the ultrasonic performance can deteriorate.
An obstacle is then monitored by the electronic control unit (ECU) by translating this obstacle measurement into a voltage. When an object with a certain mass (i.e. people, kerbs, cars, etc) enters this elliptical zone a change in the electrical field is created and an increase in voltage is detected by the control unit and you are then informed by a series of audible tones how close you are to the object. The PD1-Vision also gives you a visual alert with integrated audio. You can then manoeuvre accordingly with plenty of time to react.
I'm not even on the clear whether it works by reflection of a wave or induction. Anyone interested in stuff like this here?