| 摘要 |
<p>The present invention relates to a system for controlling entrance gates to store localities in particular or to other localities open to the public. The entrance system includes an entrance passageway which is defined by posts on which gates are pivotally mounted. A sensor means functions to detect the presence of people and objects in the vicinity of the passageway and to deliver signals to a control means for controlling opening and closing of the gate. The sensing means includes at least one sonar (8, 9) which is mounted in or in the vicinity of the passageway (2) and which comprises a transmitter/receiver means for transmitting ultrasonic pulses and receiving ultrasonic pulses that are reflected from objects and persons located within the defined measuring area.</p> |
