JPS63185800A - Obstruction discriminator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an obstacle identification device, and more particularly to a device for detecting obstacles behind an industrial vehicle such as a forklift truck.

[Conventional technology]

Industrial vehicles often travel backwards, and forklift trucks in particular often cannot see forward at all when handling large loads, so they often move only in reverse.

In order to prevent collisions with rear obstacles when reversing, conventional practice has been to install an ultrasonic sensor in the rear of a forklift truck to detect rear obstacles and send out an alarm signal when an obstacle is detected. .

[Problem that the invention seeks to solve]

However, conventional ultrasonic sensors cannot distinguish between people and objects. Therefore, when working indoors, especially in narrow spaces such as aisles or between shelves, ultrasonic sensors detect surrounding equipment such as pillars and walls of buildings, as well as piles of luggage, and the alarm goes off. Very annoying.

As a result, the worker's attention to the alarm becomes distracted, and there is a problem in that even if the alarm goes off because someone is behind the worker, the operator will not be able to respond appropriately.

Furthermore, some workers disable the alarm circuit if the alarm is noisy, and in this case, even if someone unexpectedly passes behind the forklift truck, the alarm will not go off, which is extremely dangerous. be.

[Object of the Invention] In order to solve the above-mentioned problems, an object of the present invention is to provide an obstacle identification device that can distinguish between people and objects.

[Means for solving problems]

In the present invention, an ultrasonic sensor and a heat ray sensor are arranged side by side, both sensors are connected to a detection signal identification processing circuit, the detection signal identification processing circuit is provided with a processing condition setting switch, and an obstacle connected to an alarm device is provided. An identification device solves the above-mentioned problems.

〔Example) Hereinafter, the present invention will be described in detail based on the illustrated embodiments.

FIG. 1 is a plan view of the rear part of the forklift truck according to the present invention, and the case 4 of the obstacle identification device main body is located at a location where obstacles at the rear of the forklift truck are detected, such as the upper part of the counterweight 7. installed.

As shown in FIG. 2, the case 4 of the obstacle identification device main body has a heat ray sensor 1 and an ultrasonic transmitter 2 and an ultrasonic receiver of an ultrasonic sensor on its front side (that is, the surface facing the rear of the forklift). A container 3 is provided.

The heat ray sensor 1 condenses thermal energy (far infrared rays) emitted by substances within the detection range onto the receiving section.When an object enters the detection range, it detects the thermal energy emitted by the human body and detects the presence of the person. Detect the presence of. As a heat ray sensor,
Some are highly accurate and expensive, such as those used for infrared homing, in which missiles detect the infrared rays emitted by their targets and automatically guide and track the target. However, the heat ray sensor used in the present invention may be a low-priced product that is commercially available under the trade name "infrared sensor" and widely used for opening and closing automatic doors.

The ultrasonic sensor can be similar to those conventionally used for detecting rear obstacles in forklift trucks and the like.

On the upper surface of the case 4 of the obstacle identification device main body, there is a selection switch 5 for setting connection processing conditions between the heat ray sensor 1 and the ultrasonic sensor and the detection signal identification processing circuit, as described later.
Additionally, a volume adjustment knob 6 is provided for adjusting the volume of an alarm device (not shown) that transmits an alarm signal using a buzzer or the like when a rear obstacle is detected.

The volume adjustment knob 6 is used to lower the volume at night so as not to disturb people around you, or to raise the volume when the work area is so noisy that it is difficult for the worker to hear the alarm sound. be.

Next, an example of the circuit of the present invention will be explained with reference to FIG.

The heat ray sensor 1 detects thermal energy emitted by the human body 9 and sends an output signal when a person is present within the detection area, and includes a receiving section 1a and an active filter 1.
b, and is connected to the detection signal identification processing circuit 11.

The ultrasonic sensor detects a person 9 or an object 8 using ultrasonic waves, and emits an output signal when the person 9 or the object 8, or both are present within the detection area, and detects the person 9 and the object 8. It consists of an ultrasonic transmitter 2 that emits ultrasonic waves for detection, an ultrasonic receiver 3 that receives ultrasonic waves reflected from a person 9 or an object 8, and a comparison section 10. The comparison unit 1o compares the transmitted ultrasound from the ultrasound transmitter 2 and the received ultrasound from the ultrasound receiver 3, and detects the presence of a person or object within the detection area.

The ultrasonic sensor is also connected to the detection signal identification processing circuit 11 .

The detection signal identification processing circuit 11 inputs an alarm signal to an alarm device such as a buzzer via an amplifier 12. The alarm device may be provided within the case 4 or may be provided separately. The amplifier 1 is controlled by the volume adjustment knob 6 mentioned above.
You can change the gain of 2.

The detection signal identification processing circuit 11 includes an AND circuit,
It includes an OR circuit, and can be selectively switched to one of a person detection mode, an object detection mode, and a person/object detection mode by selecting the selection switch 5.

Logical product (AND) of the outputs of the heat ray sensor 1 and the ultrasonic sensor
), the detection signal identification processing circuit 11 generates an output only when both sensors have outputs, that is, when the person 9 exists within the detection area. Therefore, when the person detection mode is selected by the selection switch 5, the detection signal identification processing circuit 11 takes the AND of the outputs of the heat ray sensor 1 and the ultrasonic sensor, and detects whether or not the person 9 exists within the detection area. can do.

If there is no person in the detection ill and only an object,
The heat ray sensor 1 has no output, and only the ultrasonic sensor has 8 outputs. Therefore, in the object detection mode, by passing the output of the heat ray sensor 1 through a NOT circuit and then performing a logical product (AND) with the output of the ultrasonic sensor, it is possible to determine that the person 9 does not exist within the detection area. The presence of object 8 can be detected.

Logical sum (OR) of the outputs of the heat ray sensor 1 and the ultrasonic sensor
If there is an output from either or both of the heat ray sensor 1 and the ultrasonic sensor, an output is generated from the detection signal identification processing circuit 11. Therefore, when the person/object detection mode is selected by the selection switch 5, the detection signal identification processing circuit 11 takes the logical sum of the outputs of the heat ray sensor 1 and the ultrasonic sensor, and determines that a person 9 or object 8 is present within the detection area. can be detected.

In this case, using a method similar to the person detection mode and object detection mode described above, it is possible to identify whether the obstacle present in the detection area is a person or an object, and to output an alarm sound accordingly. For example, you can change the tone of the alarm by making it smaller when it's a person and making it louder when it's about a person.For example, when it's about an object, you can make it a relatively pleasant "pippipip" sound, and when it's about a person, you can make it a "beat-beat" sound to get attention. good.

〔Effect of the invention〕

When a forklift truck is working in a narrow aisle or between shelves, conventional ultrasonic sensors are troublesome because they react to surrounding equipment, and if the alarm is turned off, the alarm will not work if someone unexpectedly comes out, which can be dangerous. Met. In such a case, according to the present invention, for example, by selecting the person detection mode, it will not react to surrounding equipment, so it will not be bothersome, and since the alarm is activated for people, it will be possible to prevent people from unexpectedly appearing. An alarm will also go off in the event of a collision, allowing you to avoid danger.

An ultrasonic sensor alone can only tell that there is an obstacle, while a heat ray sensor alone can only tell if there is a person, but by using both an ultrasonic sensor and a heat ray sensor, obstacles can be identified.

[Brief Description of the Drawings] Fig. 1 is a schematic plan view of a part of an embodiment of the present invention, Fig. 2 is a perspective view of a sensor used in the present invention, and Fig. 3 is an example of the circuit of the present invention. FIG. 1... Heat ray sensor, 2... Ultrasonic transmitter, 3...
... Ultrasonic receiver, 4... Case, 5... Selection switch, 6... Volume adjustment knob, 7... Counterweight, 8... Object, 9... Person. Figure 1 Figure 2

Claims (1)

[Claims] 1. An ultrasonic sensor and a heat ray sensor are arranged side by side, both sensors are connected to a detection signal identification processing circuit, and the detection signal identification processing circuit is provided with a switch for setting processing conditions and is connected to an alarm device. Obstacle identification device.