JPS62172284A - Ultrasonic matter detector - Google Patents

Abstract

PURPOSE:To positively detect invading matter by securing a wide detection area, by detecting preliminarily present stationary matter and setting only the area of said matter as a non-sensitive area to remove the same from a detection area. CONSTITUTION:The reflected ultrasonic wave receiving output by an ultrasonic transmitting-receiving sensor 1 is processed by an amplifying detection circuit 3 and a detection circuit 4 and the informations of the distance and direction of preliminarily present stationery matter are outputted from a signal processing circuit 5. A non-sensitive area setting circuit 6 sets the narrow area corresponding to the stationary matter as a non-sensitive area from said informations to remove the same from a detection area. Therefore, a wide detection area is secured and only the invading matter can be surely detected.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field 1] The present invention relates to an ultrasonic object detector that detects objects using ultrasonic waves.

[Background Art] Conventionally, when an object is detected using ultrasonic waves, when an object exists within the detection area X, the ultrasonic sensor detects the object Y by receiving the reflected wave from the object. In such a conventional example, as shown in FIG. 3, even if there is a stationary object Y other than an intruding object within the detection area X, the ultrasonic sensor 1 will detect it.
There was a problem in that all stationary objects Y had to be removed from inside.

Japanese Patent Publication No. 57-21097 was proposed to solve such problems. In this conventional example, as shown in FIG. 4, distance information between a stationary object Y existing within the detection area X and the ultrasonic sensor 1 is obtained in advance, a dead zone Z is set based on the distance information, and It is sloppy to remove the influence.

However, in this conventional example, the dead zone Z is band-shaped, and the dead zone Z covers a fairly wide area, resulting in a disadvantage that the detection area X becomes narrow.

[Object of the Invention] The present invention has been made in view of the above-mentioned points, and its purpose is to make only the area where the stationary object exists as a dead area even if a stationary object exists in the detection area in advance. To provide an ultrasonic object detector capable of detecting only intruding objects, excluding them from a detection area.

[Disclosure of the Invention 1 The present invention transmits ultrasonic pulses intermittently and receives reflected waves from an object in response to the transmitted ultrasonic pulses, thereby determining the direction of the object and the distance from the object to the receiver. In an ultrasonic object detector equipped with a detection means for detecting, when a stationary object exists in the detection area in advance, the presence of the stationary object is determined from information about the direction and distance of the stationary object obtained by the detection means. The present invention is characterized in that it includes a means for removing the area from the detection area as a dead area, eliminates the influence of stationary objects existing in the detection area in advance, and secures a wide detection area.

The present invention will be explained below with reference to Examples.

夾JLLL FIG. 1 is a block diagram showing the basic circuit configuration of this embodiment. In this embodiment, ultrasonic signals are input to the ultrasonic sensor 1 that serves as a transducer and the ultrasonic sensor 1 that serves as a transducer. an amplification/detection circuit 3 for amplifying and detecting a transmission signal when the ultrasonic sensor 1 receives a reflected wave from an object; Detection area X based on the signal from 3 and the pre-delivery wave signal
a detection circuit 4 that detects each object within the interior, and a signal processing circuit 5 that determines the distance and direction from the ultrasonic sensor 1 to the object.
Then, information on the distance and direction of the existing stationary object Y is obtained in advance from the signal processing circuit 5, and the area Z where the stationary object Y exists is removed from the detection area X and set as a dead area. It is composed of a circuit 6.

If it is known in advance that a stationary object Y exists in the detection area The wave is received by sensor 1. Then, the signal processing circuit 5 detects the distance and direction from the transducer/receiver ultrasonic sensor 1 to the stationary object Y, and the information on the distance and direction is input to the dead area setting circuit 6 to determine the area Z where the stationary object Y exists. After that, the operation of the detector is controlled so as to exclude this area Z° from the detection area X.

[Effect of the Invention 1] In the ultrasonic object detector configured as described above, when a stationary object is previously present in the detection area, the information on the direction and distance of the stationary object obtained by the detection means is Therefore, even if a stationary object already exists in the detection area, the stationary object is not detected and only the intruding object is detected. This device can reliably detect It has the advantage that it can be used in

[Brief explanation of drawings]

FIG. 1 is a circuit block diagram of an embodiment of the present invention, FIG. 2 is an explanatory diagram of the detection area same as above, and FIGS. 3 and 4 are explanatory diagrams of the detection area of the conventional example. 1 is an ultrasonic sensor that serves as both a transducer and receiver, 2 is a transmission signal generation circuit, 3 is an amplification/detection circuit, 4 is a detection circuit, 5 is a signal processing circuit, 6 is a dead area setting circuit, X is a detection area, and Y is a A stationary object, Z゛, is an area. Agent Patent Attorney Ishi 1) Ai 7 Figure 1 Figure 2

Claims (1)

[Claims] (1) Detection means that detects the direction of the object and the distance from the object to the receiver by intermittently transmitting ultrasonic pulses and receiving reflected waves from the object in response to the transmitted ultrasonic pulses. In an ultrasonic object detector equipped with an ultrasonic object detector, when a stationary object exists in the detection area in advance, the area where the stationary object exists is determined as a dead area based on information about the direction and distance of the stationary object obtained by the detection means. An ultrasonic object detector characterized by comprising means for removing the object from the detection area.