| 摘要 |
PURPOSE:To achieve a reduction in the cost with the saving of the number of ultrasonic sensors used, by reflecting an ultrasonic beam with a mobile reflecting plate provided movably to measure distances to an object at several points. CONSTITUTION:A mobile reflecting plate 3 for bending an ultrasonic beam at the right angle is arranged in front of an ultrasonic sensor 1 is inclined at 45 deg. to the center line C of the beam while being driven to reciprocate along the center axis C with a motor 5 controlled by a motor driving circuit 4 and a pinion 6 and a rack 7. A transmitting/receiving circuit 2 and the motor driving circuit 4 are controlled with a control circuit 8 to emit an ultrasonic beam from the ultrasonic sensor 1 each time the mobile reflecting plate 3 moves by a fixed distance and reflected waves from an object 9 are detected to convert a time difference between the transmission and the reception of the waves into a distance. The distance to each position of project from the ultrasonic sensor 1 is subtracted from the results to calculate the distance to the object 9 from the mobile reflecting plate 3.
|
