| 摘要 |
The invention concerns a method and device for the control of an object, for example a vehicle window or sliding roof, moved by a motor drive, and is particularly suitable for use for collision-protection purposes. The invention uses surfaces waves in the zone which is monitored, thus making it possible to mount the transmitter and receiver more simply on the object to be moved. The invention is characterized in that at least one wave-mode converter (3, 4, 34, 34', 34", 34"', 34"") is mounted in such a position that it can monitor the zone (5, 5') to be monitored, or a zone connected to the zone (5, 5') to be monitored, the mode converter being used to a) convert a bulk wave moving towards the monitoring zone (5, 5') into a surface wave and/or b) convert a surface wave moving towards the receiver into a bulk wave. The wave-mode converter (34', 34", 34"', 34"") is preferably made up of several elements disposed at regular intervals in the direction of propagation of the surface wave with a spacing t corresponding approximately to the wavelength 'lambda' of the surface wave. |
