JPH0538655A - Safety monitoring system for working machine - Google Patents

Abstract

PURPOSE:To quickly judge the safety over a wide range without resulting incremental number of sensors installed, by storing the one-field data for the original image, preparing the difference data through comparison of the current image with the original image in memory, and passing a judgement about safety according to the difference data lying within the specified hazardous region or not. CONSTITUTION:Video signals given by a TV camera 4 are fed to 21 video processing part 5 and entered into an image processing part 6 at a specified intervals. When receiving a record command from an MPU 1, the image processing part 6 stores the data from the video processing part 5 in a reference picture field memory 3, and reads the data out of this memory 3 in other cases, compares it with the data from the video processing part 5, and stores the difference data in a locus picture field memory 2. The difference data in this memory 2 is read by the MPU 1 at certain intervals and compared with the contents of a hazardous region pattern memory 1a, and when it is judged that the difference data lies within the hazardous range, an event signal is given to an audio output device 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a safety monitoring system, and more particularly to whether an alarm is issued when an operator enters a dangerous area of a work machine having a work area which is preset. , A safety monitoring system that performs processing for stopping the operation of the work machine.

[0002]

2. Description of the Related Art Work robots, work machines such as excavators, cranes, and other civil engineering and construction machines have conventionally been equipped with, for example, a mechanical detection mechanism using a limit switch or an optoelectronic device such as an infrared phototransistor. A safety system using a sensor has been implemented, and various safety systems have been proposed.

In the latter one using an infrared phototransistor, the interruption of the light is converted into an electric signal and sent as an object detection signal to a control device such as a CPU, and the control device stops the work machine in response to this detection signal. And an event signal output (an output signal for the device to take a safe operation) for generating a warning or a message for avoiding danger by voice.

Since the detection signal from the photoelectric sensor has a one-to-one correspondence with the detection location, in this method, one sensor must be installed at a location where an operator or the like is supposed to intrude. Further, the area where the former mechanical detection mechanism can be detected is a narrow range. However, there are many dangerous areas to be detected in the work machine, and provision of one sensor or detection mechanism is not practically useful.
Therefore, normally, sensors and the like for safety monitoring must be provided at a plurality of locations for one work machine.

[0005]

In working machines, improving safety is an important issue, and therefore, the number of places where sensors are installed is increasing along with the improvement in safety. Along with this, the work on the hardware side such as the wiring work for the sensor, the wiring inspection check work, and the like is increased, and the work efficiency is reduced.

Further, in the case of changing, enlarging or reducing the form of the work machine, it is necessary to change the number of safety sensors, the type of safety sensors, the position of the safety sensors, etc., and this occurs. The number of design steps to be performed increases, and a lot of labor and time are required. Moreover, in the control by a microprocessor (MPU) or the like, normally, one input terminal is assigned to one sensor, which occupies the address of the MPU, so that the number of safety sensors does not increase. In addition to increasing the number of danger notification motion decisions,
As a result of the judgment processing taking a long time, there is a high risk that the safety is lowered. An object of the present invention is to solve the above-mentioned problems of the conventional technology, and enables high-speed safety judgment over a wide range without increasing the number of sensors, and thus the safety of a work machine with high reliability. To provide a surveillance system.

[0007]

A feature of the safety monitoring system for a working machine of the present invention that achieves such an object is that an image of the working machine before entering the working state is sampled as an original image and one screen is displayed. Minute image data, the current image at the time of entering the working state is sampled as one screen data, the one image data of the original image is compared with the corresponding screen, and the difference image data is generated and stored. Is sampled at a predetermined cycle, image data of this difference is generated at a predetermined cycle, and a screen corresponding to a screen indicating a dangerous area set in advance for the sampled image for the stored difference image data is displayed. The data is compared with the corresponding screen position, and when the difference image data is in the dangerous area, an alarm or an event output for stopping the work machine is generated.

[0008]

In this way, one screen data of the original image is stored, the difference image data is taken corresponding to the screen by comparing with the current image, and it is determined whether the difference image data is in the dangerous area or not. By determining whether or not it is safe, it is possible to perform safety management in a wide range without providing an individual sensor. Moreover, it is possible to realize a safety system that can be commonly used regardless of the type of work machine.

[0009]

1 is a block diagram of a system of an embodiment to which a work machine safety monitoring system of the present invention is applied, FIG. 2 is an explanatory view of image processing thereof, and FIG. 3 is a work machine and safety. It is explanatory drawing which shows the relationship of a monitoring system. The video signal output from the TV camera (CCD camera) 4 is
The video signal for one screen, which is input to the video processing unit 5 having an A / D converter, is converted into multi-tone digital data by the A / D converter and taken into the image processing unit 6 at a predetermined cycle. The image processing unit 6 is controlled by the MPU 1 and when receiving the control signal of the recording command of the reference screen from the MPU 1, expands the data from the video processing unit 5 into the display data for one screen in the reference screen memory 3 and outputs the original data. Store as an image. In other cases, the data for one screen stored in the reference screen memory 3 is read in correspondence with the predetermined cycle of the video signal acquisition, and the data from the video processing unit 5 is compared with the corresponding screen position. The differential data for one screen is extracted and the differential data is stored in the locus screen memory 2 having a storage capacity of one screen for each screen position. If the difference data in this case is negative, it is set to “positive” and the absolute value of the difference data is taken.

As a result, the difference data in the trajectory screen memory 2 is sequentially stored in a predetermined cycle, and when the difference data is a moving object such as a person, the trajectory is stored. Become. The differential data in the locus screen memory 2 is periodically read by the MPU 1 in correspondence with the predetermined cycle, and is compared with the level of a predetermined threshold TH (see (c) of FIG. 2) to be binarized. To be done. This results in binary data from which noise components have been removed, and this binary data is compared with the contents of the dangerous area pattern memory 1a corresponding to the screen provided in the MPU 1 at the binary level.
In the binarization in this case, if the detection side such as an operator is a black level, a black level below a certain level is set to the black level, or black and white is inverted to perform a comparison process with the threshold level to obtain a white level. The determination process for setting is performed. Further, the white level judgment or the black level judgment in this case may be relatively decided in relation to the level of the object to be detected.

As a result of this comparison, when it is not within the range of the pattern of the dangerous area memory 1a, the MPU 1 clears the contents of the trajectory screen memory 2. As a result, the content of the newly stored locus screen memory 2 is judged by the next reading. On the other hand, when it is within the range of the pattern of the dangerous area pattern memory 1a in the above determination,
The event signal is sent to the audio output device 8, and the speaker 9
A message indicating a danger flows from the MPU 1, and an event signal for temporarily stopping the operation of the work machine is sent from the MPU 1. In the above case, the dangerous area pattern memory 1
The content of a is set by setting a flag in the dangerous range corresponding to the screen position, and setting of this flag causes the original image to be displayed on the display and the flag corresponding to the position of the dangerous area in the displayed image to be set. By setting and reading the coordinates of the flagged screen, it is possible to easily generate the data of the dangerous area corresponding to the screen position. It is also possible to change the content of the flag according to the degree of danger, and manage the danger notification operation and the work machine stop operation separately.

By the way, the data of the trajectory screen memory 2 is
In the image processing unit 6, the video signals are sequentially converted and sent to the video deck 7 and recorded. In this way, if the data of the movement locus is sequentially stored in the video deck 7, it can be used for analysis of the state when an accident occurs.

In FIG. 2A, when the video of the work machine 11 shown in FIG. 3 is sampled by the monitoring system 12 and stored in the reference image memory 3, the content is serially read out as one screen of data. The luminance signal at this time is shown in an analog manner. Such data is registered as a reference image in the reference screen memory 3 as a digital value under the control of the MPU 1. FIG. 2B shows a state where an object having a brightness level such as the operator 10 is added to the data of the reference image when the data is serially read out. 6C shows a signal of the difference data stored in the trajectory screen memory 2, and FIG. 7D shows the position of the flag stored in the dangerous area pattern memory 1a.

Here, for example, the overall color of the work machine is
Painting is performed with a color scheme having high white brightness, and the reference image data obtained by this is used as a gradation color close to the white level.
On the other hand, in general, many intruding objects are workers, and a helmet or a dark blue work cap is worn over the head, and the coloring is a relatively low-brightness gradation color. As a result, it is possible to obtain more clear difference image data. On the other hand, if the original image data stored in the reference screen memory 3 of this embodiment is close to the black level, an operator or the like can wear a belt close to the white level to obtain the difference image data. Good. In addition, the information in which the video signal has multiple gradations may have a difference in gradation that can generate difference image data. If multi-gradation data such as 128 or 256 is used, the target image and the original image can be obtained. Even if there is a portion having the same luminance level in and, different portions also occur, and it is possible to obtain the data of the gradation difference regardless of the luminance level of the detection target.

As described above, when there is difference data corresponding to the position of the flag of the dangerous area pattern memory 1a, the danger warning process is performed and the event output is MPU1.
Arises from. If this event output is connected to a device that issues an alarm or a device that turns ON / OFF the actuator, it is possible to notify the worker and stop the entire device, thereby ensuring the safety of the worker.

As described above, in the embodiment, the camera 4 is a normal camera, but an infrared camera may be used to record the image captured. In particular,
When an infrared camera is used, the heat sensor has a white level, so that the image on the working machine side can be sampled in a state close to a black level and the original image can be stored. In this case, when there is a white level portion on the work machine or the like, it is preferable to set a limit so that the original image does not exceed a certain level (not to approach the detected white level). ..

[0017]

As can be understood from the above description, according to the present invention, one screen data of the original image is stored, and the difference image data is compared with the current image corresponding to the screen, It is possible to perform safety management in a wide range without providing an individual sensor by determining whether or not the image data of is in a dangerous area and whether or not it is safe. Therefore, the number of safety sensors installed in the dangerous area is reduced, and the reliability of safety notification is increased. Also, since the number of sensors is reduced, the man-hours for wiring work, wiring inspection check, and sensor installation work are reduced, and the assembly man-hours are reduced. Moreover, it is possible to realize a safety system that can be commonly used regardless of the type of work machine.

[Brief description of drawings]

FIG. 1 is a block diagram of a system of an embodiment to which a work machine safety monitoring system of the present invention is applied.

FIG. 2 is an explanatory diagram of the image processing.

FIG. 3 is an explanatory diagram showing a relationship between a work machine and a safety monitoring system.

[Explanation of symbols]

1 ... MPU, 2 ... locus image memory, 3 ... reference image memory, 4 ... camera, 5 ... video processing unit, 6 ... image processing unit,
7 ... VCR, 8 ... Audio output device, 9 ... Speaker,
10 ... Operator, 11 ... Work machine, 12 ... Monitoring system.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor, Hajime Mizutani, 650, Kazunachi-cho, Tsuchiura-shi, Ibaraki Hitachi Construction Machinery Engineering Co., Ltd.

Claims (2)

[Claims] 1. An image of the work machine in a state before entering a working state is collected as an original image and stored as data for one screen, and a current image at the time of entering the working state is collected as data for one screen, Image data of the difference is generated and stored by comparing with one screen data of the original image corresponding to the screen, sampling of the current image is sampled at a predetermined cycle, and image data of this difference is generated at a predetermined cycle. Then, the stored image data of the difference is compared with the data corresponding to the screen indicating the dangerous area set in advance for the sampled image in correspondence with the screen position, and the image data of the difference enters the dangerous area. A work machine safety management system that generates an alarm or an event output that stops the work machine when the work machine is in operation. 2. The work according to claim 1, wherein the brightness of the data of the original image is stored in advance by limiting the brightness to a predetermined level, and a difference is provided with respect to the brightness level of the operator in the current image. Machine safety management system.