| 摘要 |
An improved transducer for a proximity sensing system using a sonar transmitter is disclosed. An autonomous device provided with a number of motor-driven wheels further comprises a number of elements for the proximity navigation and guiding of the device such as a microprocessor system and a proximity ultrasonic sensing system comprising at least one transmitting member and one receiving member. The transmitting member is formed by the ultrasound transducer (11), which is positioned behind a wire mesh at the front of the device. The device transmits ultrasonic waves from a first strip-shaped device (21) with a narrow vertical distribution within a wide horizontal sector, and a second strip-shaped device (22) providing a wider vertical distribution within a similarly wide horizontal sector in front of the autonomous device. The proximity sensing system comprises a number of microphone units provided with hollow pipes for the sound and forming a input portion of a receiving system for receiving echoes of the transmitted ultrasonic waves reflected from objects in the forward course of the moving device. With this arrangement of transmitting and receiving, echoes from the floor or ground as well for instance sharp edged carpets or the like will be heavily suppressed. This then gibes a much more simplified detection of objects in the zone near to the device, where echoes from a floor or ground and the device itself become very strong.
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