JPH0555090U - Obstacle detection device - Google Patents

Abstract

(57) [Summary] [Purpose] To facilitate the detection of obstacles, especially at short distances. [Structure] The ultrasonic sensor 1 and the infrared sensor 4 are used together, and the infrared sensor 4 is used to detect an obstacle at a short distance. Since the infrared sensor 4 transmits and receives an infrared signal without being affected by phenomena such as wraparound and reverberation unlike the ultrasonic sensor 1, it is possible to accurately detect an obstacle.

Description

[Detailed description of the device]

[0001]

[Industrial application]

 The present invention relates to an obstacle detection device installed in a vehicle or the like to detect the presence or absence of an obstacle.

[0002]

[Prior Art]

 2. Description of the Related Art There is known an obstacle detection device which is installed in a vehicle or the like and detects the presence or absence of an obstacle behind the vehicle so as to perform a safe driving, especially when performing backing.

FIG. 2 shows a schematic structure of a conventional obstacle detection device. Reference numeral 1 denotes an ultrasonic sensor that transmits an ultrasonic signal to the obstacle 12 and receives a reflected signal from the obstacle 12, 2 Is a receiving amplifier for amplifying the received signal, 13 is a control circuit for calculating the distance to the obstacle from the arrival time from transmission to reception, and 3 is a drive circuit for generating ultrasonic waves from the ultrasonic sensor 1.

By installing such an obstacle detection device at the rear position of the vehicle, it is possible to detect the presence or absence of the obstacle 13 when performing back, and to detect the distance to the obstacle 13 when it is present. Therefore, it is effective for safe driving.

[0005]

[Problems to be solved by the device]

 By the way, the conventional obstacle detecting device has a problem that it is difficult to detect an obstacle existing in a short distance especially due to the property of the ultrasonic sensor. In other words, the ultrasonic signal causes phenomena such as wraparound and reverberation, so when detecting an obstacle at a short distance, it is affected by such a phenomenon and the presence or distance of the obstacle is accurately detected. It becomes difficult to do.

The present invention has been made in consideration of the above problems, and an object thereof is to provide an obstacle detection device which facilitates detection of an obstacle existing in a short distance.

[0007]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention provides an ultrasonic sensor that transmits and receives ultrasonic signals to and from an obstacle, an infrared sensor that transmits and receives infrared signals to and from the obstacle, and It has a control means for transmitting and receiving a signal from at least one of both sensors and calculating the distance to the obstacle from the arrival time of the signal.

[0008]

[Action]

 An infrared sensor is used in addition to the ultrasonic sensor, and either one or both sensors are operated according to the distance to the obstacle. Therefore, when detecting an obstacle existing at a short distance, it is easy to detect the obstacle by operating the infrared sensor that is not affected by wraparound and reverberation.

[0009]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of an obstacle detecting device of the present invention, wherein 1 is an ultrasonic sensor for transmitting an ultrasonic signal to an obstacle 12 and receiving a reflected signal from the obstacle 12, 2 Is a reception amplifier for amplifying the ultrasonic wave reception signal, 3 is a drive circuit for generating ultrasonic waves from the ultrasonic wave sensor 1, and 4 is an infrared signal to the obstacle 12 and a reflected signal from the obstacle 12 is received. The infrared sensor 5 is a reception amplifier for amplifying an infrared reception signal, and 6 is a drive circuit for generating infrared rays from the infrared sensor 4. Here, as the ultrasonic sensor 1 and the infrared sensor 4, a type that can detect the distance to an obstacle from the arrival time from the transmission of the ultrasonic signal and the infrared signal to the reception thereof is used.

Reference numeral 7 is a signal switching circuit for switching either one of the drive circuit 3 and the drive circuit 6 or both of them based on a switching signal from a microcomputer to be described later, and 8 is an ultrasonic sensor 1 and an infrared ray. The control operation is performed so that at least one of the sensors 4 is operated, and the distance to the obstacle 12 is calculated from the arrival time from the transmission of the ultrasonic signal and the infrared signal to the reception, and further the entire control operation is performed. It is a microcomputer (microcomputer) that does.

Reference numeral 9 indicates, in advance, the distance to be detected, the alarm setting, the individual detection setting by the ultrasonic sensor or the infrared sensor, the buzzer on / off setting, the sensor on / off setting to the microcomputer 8 in advance in the detection. There is a control switch for setting, etc., 10 is a buzzer that turns on when a preset detection distance is reached, and 11 displays the detection distance and whether this detection is by the ultrasonic sensor 1 or the infrared sensor 4 In other words, it is a distance display circuit that displays the distinction between the two modes.

In the above configuration, for example, when the obstacle 12 existing at a short distance (50 cm as an example) is detected, the mode by the infrared sensor 4 is set by the control switch 9 in advance, and the microcomputer is set based on the mode. Reference numeral 8 outputs a switching signal to the signal switching circuit 7 to operate only the drive circuit 6. As a result, the drive circuit 6 drives the infrared sensor 4, so that the infrared sensor 4 transmits an infrared signal to the obstacle 12.

The infrared signal reflected by the obstacle 12 is received again by the infrared sensor 4, amplified by the receiving amplifier 5, and output to the microcomputer 8 via the signal switching circuit 7. The microcomputer 8 determines the distance from the obstacle 12 to the infrared sensor 4 based on the arrival time of the infrared signal transmitted from the infrared sensor 4, reflected by the obstacle 12, and received by the infrared sensor 4 again. Calculate

The calculated distance is sequentially displayed on the distance display circuit 11 together with the mode distinction (in this case, the infrared mode). When the calculated distance becomes equal to the distance preset by the control switch 9, the buzzer 10 is turned on. As a result, the driver can detect the obstacle 12 as well as the distance to the obstacle.

According to the present embodiment as described above, particularly when the obstacle 12 existing at a short distance is detected, the infrared sensor 4 that does not cause a phenomenon such as wraparound and reverberation is used like the ultrasonic sensor 1. As a result, since there is no reverberation of such a phenomenon, an obstacle existing in a short distance can be easily detected.

The obstacle detection device according to the present embodiment is effective not only in the rear position of the vehicle but also in the front position. When an ultrasonic sensor is used as in the past, when an interference signal from another vehicle is received, it is often detected as an obstacle and false detection is performed. , Such inconvenience is eliminated.

Further, even when the distance is not short, only the ultrasonic sensor 1 is operated according to the distance, or the infrared sensor 4 and the ultrasonic sensor 1 are simultaneously operated, whereby the obstacle can be accurately detected.

[0018]

[Effect of the device]

 As described above, according to the present invention, the ultrasonic sensor and the infrared sensor are used together, and the infrared sensor is used especially when detecting an obstacle existing at a short distance. Can be done easily.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of an obstacle detection device of the present invention.

FIG. 2 is a schematic block diagram showing a conventional obstacle detection device.

[Explanation of symbols]

 1 Ultrasonic sensor 4 Signal switching circuit 8 Microcomputer 9 Control switch 12 Obstacle

Claims (1)

[Scope of utility model registration request] 1. An ultrasonic sensor that transmits and receives ultrasonic signals to and from an obstacle, an infrared sensor that transmits and receives infrared signals to and from an obstacle, and at least one of the two sensors depending on the distance to the obstacle. An obstacle detection device comprising: a control unit that transmits and receives a signal and calculates a distance to an obstacle from the arrival time of the signal.