JPS6151584A - Operation controller of vehicle circumference monitoring device utilizing ultrasonic wave - Google Patents

Abstract

PURPOSE:To improve the reliability of the device by allowing the vehicle circumference monitoring device to operate only when a vehicle speed is lower than a specific vehicle speed under the control of an operation controller. CONSTITUTION:When a main switch 54 for operating the vehicle circumference monitoring device 20 is turned on when the vehicle speed is lower than the specific vehicle speed, a vehicle speed detector 30 outputs a high-level signal, so a transistor (TR) 41 turns on as long as an ignition key 53 is already on to power on a relay coil 42, thereby making a contact 43. Consequently, the circumference monitoring processing circuit 22 of the device 20 is supplied with electric power to start operating. At this time, the vehicle speed is low, so there is a small number of ultrasonic waves in noises in the circumference of the vehicle and the ultrasonic wave transmitted by an ultrasonic transmitter and receiver 21 is received distinctively as an ultrasonic wave in noises as long as it is modulated at a specific frequency, thereby detecting an obstacle that the vehicle approaches.

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention provides an ultrasonic transmitter/receiver that is installed at a suitable location on a vehicle body toward the periphery of the vehicle, and a transmission/reception time difference between ultrasonic waves transmitted and received in this ultrasonic transmitter/receiver. This invention relates to an ultrasonic vehicle surroundings monitoring device that measures the distance to obstacles around the vehicle.

[Conventional technology]

This type of vehicle surroundings monitoring device is disclosed in Japanese Patent Application Laid-Open No. 57-54879.
-54881 and the like.

There is noise containing ultrasonic waves around the vehicle, and in order to distinguish the ultrasonic waves emitted from the ultrasonic transceiver from the ultrasonic waves in the noise and receive them, conventionally, the ultrasonic transceiver transmits and receives the ultrasonic waves. modulates the ultrasonic wave at a predetermined frequency,
Only when modulated ultrasonic waves are received, they are taken into the processing circuit to measure the distance to the obstacle.

[Problem that the invention seeks to solve]

However, by transmitting and receiving modulated ultrasonic waves in this way, even if the ultrasonic transceiver distinguishes between the transmitted ultrasonic waves and the ultrasonic waves contained in the surrounding noise and receives them, the increase in vehicle speed is As a result, if the number of ultrasonic waves contained in the noise increases considerably, the modulated ultrasonic waves will be buried in the ultrasonic waves in the noise, making it difficult to identify the modulated ultrasonic waves.
1. As a result, the vehicle surroundings monitoring device will malfunction.

Therefore, an object of the present invention is to prevent malfunction of a vehicle surroundings monitoring device in a vehicle speed range where the amount of ultrasonic waves contained in noise increases.

[Means for solving problems]

Therefore, the present invention is characterized in that the actual operation of the vehicle surroundings monitoring device is limited to only a region where the vehicle speed is relatively low.

Specifically, in the vehicle surroundings monitoring device as described above, there is a vehicle speed detector that detects whether the vehicle speed is in a low speed state lower than a predetermined vehicle speed, and when the vehicle speed detector detects that the vehicle is in a low speed state. , and an operation controller that operates the vehicle surroundings monitoring device.

(Operation) Therefore, the operation controller operates the vehicle surroundings monitoring device only while the vehicle speed is lower than a predetermined vehicle speed, and stops the operation of the vehicle surroundings monitoring device when the vehicle speed becomes higher than the predetermined vehicle speed.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an electrical circuit diagram of an embodiment of the present invention, in which 20 is a vehicle surroundings monitoring device, 30 is a vehicle speed detector, and 40 is a vehicle surroundings monitoring device.
is the actuation controller.

The vehicle surroundings monitoring device 20 consists of an ultrasonic transmitter/receiver 21, a surroundings monitoring processing circuit 22, and an alarm 23. 22, this ultrasonic transceiver 21
The distance to obstacles around the vehicle is measured by measuring the time difference between transmission and reception of ultrasonic waves transmitted and received.

The distance to the obstacle measured in the surrounding monitoring processing circuit 22 is a predetermined minimum value, for example, 50 crn.
When the obstacle becomes smaller than , a signal is sent from the surrounding monitoring processing circuit 22 to the alarm 23 to display an alarm indicating the approach of the obstacle.

FIG. 2 is a plan view of the vehicle, and as shown by 21a to 21e in the figure, there are 5 ultrasonic transceivers 21 in total, one at each of the four corners of the vehicle body 10 (one at each flit and one at the rear central part). A number of sensors are installed so that obstacles in each direction can be monitored.

On the other hand, the vehicle speed detector 30 has a known configuration consisting of a vehicle speed sensor 31, an F-■ converter 32, a vehicle speed setter 33, and a comparator 34, and the vehicle speed sensor 3I is disposed within a speedometer (not shown). Every once in a while, an on-off signal whose cycle is inversely proportional to the vehicle speed is sent to the F-V converter 32, and the F-■ converter 32 converts the on-off signal from the vehicle speed sensor 31 into a voltage signal proportional to the vehicle speed.
It is supplied to the comparison terminal of the comparator 34. A voltage signal corresponding to a predetermined vehicle speed, for example 10 km/h, is supplied from the vehicle speed setting device 33 to a reference terminal of the comparator 34 . Then, in the comparator 34, the voltage from the F-V converter 32 supplied to the comparison terminal and the base 'l' r/li
It compares the voltage supplied from the vehicle speed setter 33 with the voltage supplied to the J child, and when the former is smaller than the latter, a high level signal is generated, and when the former is larger than the latter, a low level signal is generated. In other words, the vehicle speed detector 30 detects that when the vehicle speed is lower than the predetermined vehicle speed,
A high level signal is output.

Further, the operation controller 40 includes an NPN transistor 41,
The transistor 41 consists of a relay coil 42 and its contacts 43, and its base is supplied with the output of the vehicle speed detector 30, and its collector and emitter are connected to the relay coil 42.
is connected to an on-vehicle battery 51 which is a power source. Contact 4
3 is a type that is turned on when the relay coil 42 is energized and turned off when it is not energized, and this contact 43 is connected to the periphery monitoring processing circuit 22 of the vehicle periphery monitoring device 20.
The power supply circuit is inserted into the power supply circuit and can open and close this power supply circuit. The relay coil 42 and the contact 43 on the battery 51 side are commonly connected to each other.
is inserted.

Next, the effect will be explained.

Vehicle surroundings monitoring bag W20 when the vehicle speed is lower than the specified vehicle speed
When the main switch 54 is turned on to activate the relay coil 4, the vehicle speed detector 30 outputs a high level signal, so if the ignition switch 53 is also turned on, the transistor 41 becomes conductive and
2 is energized and the contact 43 is turned on. For this reason,
Power is supplied to the surroundings monitoring processing circuit 22 of the vehicle surroundings monitoring device 20, and the operation is started. At this time, because the vehicle speed is low, there are few ultrasonic waves contained in the noise around the vehicle.
If the ultrasonic waves transmitted by the ultrasonic transceiver 21 are modulated at a predetermined frequency, they can be received separately from ultrasonic waves in noise, and obstacles approaching the vehicle can be detected without malfunction. I can do it.

As the vehicle speed increases and becomes higher than the predetermined vehicle speed, the amount of ultrasonic waves contained in the noise around the vehicle increases, but at this time, the vehicle speed detector 30 no longer outputs a high level signal, and instead outputs a low level signal. Therefore, the transistor 41 becomes non-conductive, the relay coil 42 becomes non-conducting, and the contact 43 becomes non-conductive.
is turned off, and even if the ignition switch 53 and main switch 54 are turned on, the power supply circuit of the peripheral monitoring processing circuit 22 is cut off. Therefore, the operation of the vehicle surroundings monitoring device 20 is stopped, and it is possible to eliminate the problem of the alarm 23 erroneously operating due to the influence of ultrasonic waves contained in the noise. Also, a vehicle surrounding surveillance bag? i! Since the function 20 is highly necessary when driving at low speeds and less necessary during normal driving, there is no practical problem even if the vehicle surroundings monitoring device 20 is deactivated in a vehicle speed range higher than a predetermined vehicle speed. .

Although specific embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and includes various embodiments within the scope of the claims. For example, the vehicle surroundings monitoring device may apply the brakes to the vehicle instead of issuing a warning when the distance to an obstacle is small. Further, the operation controller may be one that controls the actual operation of the vehicle surroundings monitoring device, for example, it may be one that limits the operation of the alarm only in a low speed range.

(Effects of the Invention) According to the present invention, the operation controller allows the vehicle surroundings monitoring device to operate only in a vehicle speed range lower than a predetermined vehicle speed, and does not operate in a vehicle speed range higher than the predetermined vehicle speed. Since the vehicle stops, the vehicle surroundings monitoring device will not malfunction even if there is a large amount of ultrasonic waves contained in the noise while the vehicle is running at a speed higher than the predetermined vehicle speed, increasing the reliability of the vehicle surroundings monitoring device. I can do it.

[Brief explanation of drawings]

FIG. 1 is an electrical circuit diagram of an embodiment of the present invention, and FIG.
FIG. 3 is a plan view of a vehicle showing an installed state of an ultrasonic transceiver. 10...-Vehicle body 20--Vehicle surrounding monitoring device 21.21a-21e...-Ultrasonic transmitter/receiver 30--
---Single vehicle chain detector 40--...operation υJ controller

Claims (1)

[Claims] 1. An ultrasonic transmitter/receiver is installed at an appropriate location on the vehicle body toward the surroundings of the vehicle, and the distance to obstacles around the vehicle is measured based on the difference in transmission and reception time of ultrasonic waves transmitted and received by the ultrasonic transmitter/receiver. An ultrasonic vehicle surrounding monitoring device that uses ultrasonic waves includes: a vehicle speed detector that detects whether the vehicle speed is in a low speed state lower than a predetermined vehicle speed; An operation control device for an ultrasonic vehicle surroundings monitoring device, comprising: an operation controller for operating the device;