JP2981946B2 - Work machine alarm system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an alarm system used for a working machine such as a civil engineering or construction machine having an upper revolving structure such as a hydraulic shovel, a crane, etc. The present invention relates to an alarm system capable of generating an alarm individually for an approaching object and according to the form and operation state of a work machine and dynamically managing safety.

[0002]

2. Description of the Related Art At construction sites, road pavement sites, and civil engineering work sites, there are many types of work in which construction machines and workers intersect. Also, depending on the location, ordinary people visit or carry in and out various machines used in connection with the work, and there are also obstacles. Then, when these workers, ordinary people, obstacles, and the like are behind or diagonally obstruct the driver's vision of the work vehicle or the like, there is a very high risk of an accident. Therefore, various safety systems have been conventionally proposed. One of them is an ultrasonic echo method. The ultrasonic echo system is a system that captures an echo from an object reflecting ultrasonic waves and generates an alarm for an object in an alarm area.

[0003]

A conventional alarm system using the ultrasonic echo method is applied to a system other than a worker, for example, obstacles such as grass and trees, work equipment and equipment which should not generate an alarm. However, there is a drawback that an alarm is generated in response to the alarm, and the alarm is too sensitive to be practical. In order to solve such a drawback, a transponder system has been proposed as an alarm system using ultrasonic waves. In the transponder system, a driver and a worker are divided into a master station and a slave station to exchange information. The slave worker
A device that receives ultrasonic waves transmitted from the vehicle serving as the master station is installed, and the ultrasonic waves from the vehicle are received, the slave station's alarm is sounded, the transmission and reception are switched, and the main station is switched to a different frequency from the reception frequency. Call the station. On the other hand, a vehicle serving as a master station is a system that receives a signal from a slave station in a detection area and issues a warning to a worker from the vehicle side when a signal from the slave station is received. By receiving a response from the slave station at a frequency different from the frequency of the master station, reflection from an unrelated obstacle (having the same frequency as that of the master station) and a slave station (different frequency response from workers, etc.) Can be distinguished.

However, even if such a transponder method is used, if the detection area is enlarged in order to ensure higher safety, the reflected wave receiving area of the ultrasonic wave is expanded accordingly, and even an irrelevant obstacle in the surroundings is warned. However, there is a problem that the risk of occurrence of an error increases, and if the detection area is limited, the security decreases. In order to solve such a problem, the present inventors have proposed an alarm system for a working machine which determines a risk by setting a plurality of virtual risk potential zones around the working machine. One has already filed an application for this in Japanese Patent Application No. 3-205366. This method is based on determining which of the set virtual risk potential zones contains a detection target (including a person). The faster this determination process is, the shorter the time until an alarm is generated, and higher security can be secured. However, the work machine also changes its posture in addition to the arm, the boom, the attachment, and the revolving structure. Therefore, if the potential zone is set accordingly, the above-described determination process takes time. On the other hand, there is a strong demand that the determination time can be shortened as much as possible so that the determination can be performed instantaneously. Further, there is also a demand for issuing an alarm while distinguishing whether a detection target is a person or a structure or equipment. However, even if a person can be distinguished from an object, in the case of a person, it is practically meaningless without careful safety management, such as whether the worker is a worker or not. The present invention responds to such a demand,
Another object of the present invention is to solve the above-mentioned problems of the prior art, and to dynamically identify an object to be approached in accordance with the operation state (including a stationary state) of a work machine to perform safety management. It is an object of the present invention to provide an alarm system for a working machine that can easily set a potential zone and can quickly determine a relationship between a zone and an object to be detected.

[0005]

The work machine alarm system of the present invention for achieving the above object is mounted as a master station on a work machine having an arm, and includes a master station transmitter, a master station receiver, and a master station receiver. A first transmission / reception device having a time measurement circuit for measuring a time from transmission of a signal from the station transmitter to reception of a predetermined signal of the main station receiver, and a different radius on a plane around the tip of the arm. Potential zone setting means for setting a plurality of virtual risk potential zones in which the risk increases toward the inside formed by the multiple circles, and a time value measured by a time measurement circuit to obtain a detection target for the work machine. Position detecting means for detecting the position, and determining means for determining whether the position detected by the position detecting means is included in any of the plurality of virtual risk potential zones And a warning means for generating an alarm,
Detecting that the detection target has moved from a low risk zone to a high risk zone among the plurality of virtual risk potential zones according to the determination result of the determining unit, drives the warning unit, and generates an alarm. A control device mounted on the work machine, a slave receiver that receives a signal from the master transmitter, a slave transmitter that generates the predetermined signal unique to the station, and a slave receiver that receives the signal from the master transmitter A control circuit for driving a slave station transmitter when a signal is received.
And a transmission / reception device.

[0006]

As described above, the distance is managed by the time from when the master station transmits to when it receives, and when the ultrasonic wave is used as the slave transmitting / receiving device, for example, the signal is transmitted as a predetermined signal unique to the station. Ultrasonic waves having a predetermined center frequency are allocated, and the ultrasonic wave receivers having different center frequencies are individually provided on the master station side to receive signals from the slave station side. Of course, when a radio signal such as a microwave is used as a transmission / reception signal, a frequency, a code signal, or the like may be used as a signal unique to the slave station. By measuring the time from transmission to reception for each such unique signal, the distance from multiple objects can be measured at the same time,
Even if there are a plurality of slave transmission / reception devices, the alarm target can be individually recognized for each center frequency (for each code). In addition, a plurality of virtual risk potential zones composed of multiple circles are set around the tip of the arm of the work machine, and when one of the circles includes a monitoring target, a circle with a low risk to a circle with a high risk is set. Since the monitoring target is detected based on the movement of the target and an alarm is sounded, it is hardly affected by noise or the like generated at random, and the alarm can be issued more safely. In addition, since it is a circular potential zone, it can be set only by the distance from the center, and even if the arm is rotating during work, which potential zone is located only by obtaining the distance from the current position of the tip to the target object The risk can be determined in the working state at high speed. As a result, it is possible to generate an alarm depending on the target, and it is possible to improve the safety of the work machine and increase the work efficiency.

[0007]

FIG. 1 is an explanatory view of an embodiment in which an alarm system for a working machine according to the present invention is applied to a hydraulic excavator. FIG. 2 is an explanatory view of the overall configuration of the hydraulic excavator, and FIG. Is an explanatory view of the mounting relationship between the receiving sensor and the ultrasonic generating horn, FIG. 4 is an explanatory view of the virtual risk potential zone, FIG. 5 is an explanatory view of the potential data table, and FIG. 6 is an operation of the hydraulic excavator. FIG. 7 is an explanatory diagram of a virtual risk potential zone set in accordance with the above, FIG. 7 is an explanatory diagram of a virtual risk potential zone set by predicting a destination in a working state, and FIG. FIG. 9 is a block diagram of a transmission / reception system for identifying a detection target in the embodiment shown in FIG. 1, and FIG. 10 is a distance for calculating a distance to the target. Block diagram of the over data generating circuit, Fig. 1
1 is an explanatory diagram for explaining the operation of the distance data generating circuit, and FIG. 12 is an explanatory diagram of a monitoring target table.
is there.

In FIG. 2, reference numeral 20 denotes a hydraulic excavator having a backhoe front attachment, and a work front attachment comprising a boom 2, an arm 3, and a bucket 4 is attached to the upper swing body 1. Reference numeral 5 denotes a traveling body provided below the revolving superstructure 1. Reference numeral 6 denotes an arithmetic control unit mounted on the hydraulic excavator 20, which has a microprocessor (MPU), a memory, and the like, and has a work range such as the boom 2 and a front attachment corresponding to the swing angle θ of the swing body 1. , The postures (angles α ₁ , α ₂ , α ₃ ) of the respective working members are controlled.
In addition, the drive control unit 8 is controlled to control driving and stopping of each work member. Reference numeral 7 denotes an alarm unit, which is provided with a buzzer and a voice synthesizing device. The buzzer informs the user of the work status and issues various alarms to a nearby object or a nearby person. In the drawing, d ₁ is a control amount for setting the angle α ₁ (not shown) of the boom 2, and d ₂ is the angle α _{2 of the} arm 3
(Not shown), and d ₃ is an angle α _{3 of the} bucket 4 (or front attachment).
(Not shown).

As shown in a partially enlarged plan view of FIG. 3, three receiving sensors 17a, 17b, 17c and 90 are provided on the vehicle body portion above the driver's seat and the right vehicle body portion of the excavator 20.
Four ultrasonic generating horns 18a, 18b,
18d and 18e are provided. These receiving sensors 17a, 17b, 17c are arranged at intervals of 120 degrees on a circumference centered on the rotation center O of the revolving unit 1. The receiving directivity of each receiving sensor is 180
Two sensors capable of switching degrees are built in, and have a directivity of 360 degrees by switching. The receiving sensors 17a and 17b are mounted so that the directivity of the excavator 20 can be switched to the front and rear of the excavator 20 so that the directivity thereof is directed to the front and rear.
It is mounted so that directivity can be switched to the left and right of the camera. On the other hand, the ultrasonic generating horns 18a, 18b, 18
d and 18e are simultaneously driven by the transmission circuit 18 and 3
Ultrasonic waves are emitted over the entire circumference at 60 degrees.

For this reason, the signals received by the receiving sensors 17a and 17b by the directivity switching of the receiving object before and after the revolving structure 1 in accordance with the rotational state of the revolving structure 1 are used as position measurement signals. Receiver, revolving structure 1
In the position on the right side, the receiving sensor 17a whose directivity is switched to the rear side and the receiving sensor 17c whose directivity is switched to the right side
The reception sensor 17b receives the signal received as a position measurement signal, and switches the directivity to the rear side on the left side.
Then, a signal received by the receiving sensor 17c whose directivity is switched to the left is received as a position measurement signal. These sensors are controlled by the arithmetic and control unit 6 into the reception detection circuit 16 and the selector 1.
5, the selection of the sensor and the selection of the detection by the reception detection circuit 16 are controlled in a time-division manner, and the signal corresponding to the selection is transmitted to the arithmetic control unit 6 via the selector 15 by the reception detection interrupt signal. Is entered as

Incidentally, the ultrasonic generating horns 18a, 18
The ultrasonic waves generated by b, 18d and 18e are, for example,
30 kHz, receiving sensors 17a, 17b, 17c
Is 20 kHz, for example, and the transmission signal and the reception signal have different frequencies. The difference is that when an alarm device (detection target 19) carried by a worker or the like as a detection target receives an ultrasonic wave of 30 kHz, an ultrasonic wave of 20 kHz is transmitted as a reception response signal. Because there is. Therefore, here
A so-called hydraulic excavator 20 is used as a master station, and a worker or the like is used as a slave station. Therefore, the ultrasonic wave generating horns 18a, 18b, 18d, and 18e are controlled by
0 kHz ultrasonic wave, for example, 0.1 sec to 0.3 sec
The arithmetic and control unit 6 having received the reception signal measures the time until the ultrasonic wave of 20 kHz is received via the reception detection circuit 16 periodically. Thereby, the distance from each sensor to the worker-side portable alarm device (slave station) can be calculated.

FIG. 1 shows the internal configuration of the arithmetic and control unit 6 for performing such processing, and particularly shows a main part mainly including a part related to the present invention. A rotation position signal obtained from a rotation position detection sensor according to the rotation of the revolving structure 1 in FIG. 2 and signals from rotary encoders and the like of various working members of the front attachment, the drive control unit 8, the reception sensor 1
Signals from 7a, 17b, and 17c are supplied to the operation control unit 6 via an interface 14 including an A / D conversion circuit.
Is taken into the MPU 10. The alarm unit 7 is controlled by the MPU 10 via the interface 14,
Driven. The MPU 10 controls the entire operation of the hydraulic excavator 20 described above, and performs control and determination unique to the present invention, processing of an alarm unit, and the like with the configuration described below.

The bus 13 has an interface 14
A memory 9 storing various programs and data, an operation panel 11, a display 12, and the like are connected in addition to the MPU 10 and the MPU 10. The memory 9 stores a center position calculation program 9a for calculating the center position of a group of potential zones for setting a virtual risk according to the work state.
And an object detection / distance calculation program 9b, a risk determination program 9c, an alarm processing program 9d, and the like. Further, the memory 9 is provided with a data table 9e such as a potential, a monitoring target table 9f, and the like.
Here, each zone between adjacent circles formed by concentric circles set as concentric circles as shown in FIG. 4 corresponds to a virtual potential zone, and the potential data table 9e stores Each zone is managed by distance (radius). Then, data on the detection target 19 is stored in the monitoring target table 9f. FIG. 12 shows an example of this table when an object is identified and monitored.

FIG. 5 shows a potential data table 9e.
Is shown. For this, the radius data of each circle in FIG.
It is tabulated for C and PD. That is,
The potential data table 9e has the zone setting center P
Rotation center O of revolving unit 1 for A, PB, PC, PD
Control amount function that generates the coordinate value for the (origin) to set the work control amount (theta for setting the posture of the working member d, the control amount d ₁ to set the angle alpha ₁ of the boom 2, the angle of the arm 3 alpha control amount d ₂ to set _2, the control amount d ₃ to set the angle alpha ₃ of the bucket 4, in relation to reference FIG. 2), f
_{pa (d, d 1, d} 2, d 3), fpb (d, d 1), fpd
(D). Note that it is not necessary to calculate the coordinates of the PC among the zone setting centers since the PC is at the origin O. Therefore, no function is required. The potential data table 9e is provided with the current coordinates Xo, Yo with respect to the origin O at the center of the concentric circle calculated according to the working state by the function, and the radius (r
i) and an array of pairs rn / Pn, dn-1 / Pn-1,... of a pair of the risk (level Pi (described later)) inside the circle of the radius.
.., R ₁ / P ₁ , and r ₀ / P ₀ are provided in order from the radius of the inner circle with high risk. Note that n is an arbitrary integer selected according to each zone.

The center position calculating program 9a is, fpa with reference to this potential data table 9e at regular interrupt processing _{(d, d 1, d 2} , d 3), fpb (d, d
₁ ) According to fpd (d), the current position of the center of each potential zone PA, PB, PD is calculated, and the values of the current coordinates Xo, Yo are periodically written to the potential data table 9e at a predetermined cycle.

FIG. 4 shows a concentric virtual risk potential zone set in correspondence with the center position of each potential zone generated by the center position calculation program 9a. Of these circles, the innermost circle with respect to the zone setting center is then covered so that each of the boom 2, the arm 3, and the bucket 4 is covered when it takes the smallest posture or the basic posture. Is provided with a radius that surrounds the posture. Also,
The potential zones of each concentric circle are calculated according to the posture of the work front attachment including the boom 2, the arm 3 and the bucket 4, and the rotation of the revolving unit 1 by periodically calculating the centers of these zones by the function. Move or rotate. Here, in particular, since the potential zone has a donut shape (circle), when the target moves from the low-risk potential zone to the high-potential zone, the moving object or the object in the moving direction is positioned at the center of the concentric circle. Will move relative to. Therefore, even if the object is not moving, it can be grasped that the posture of the work front attachment including the boom 2, the arm 3, and the bucket 4 has approached the object, and the determination of the degree of danger can be more reliably performed. Can be done.

In view of the above, an object that has moved from a low-risk potential zone to a high-potential zone is captured here. Then, an alarm is generated when the moved high potential zone is a potential zone having a predetermined risk or higher. In the drawing, the shape of the concentric circle is different between the revolving superstructure 1, the boom 2, the arm 3, and the bucket 4. this is,
This is because each risk management is different. In particular, the bucket 4 should have more circles than others. The reason is that when the revolving superstructure 1 is revolving, when the boom 2 is moving, or when the arm 3 is moving, when these plural things are operating,
This is because the degree of risk is higher than in the case of a single operation state, so that more detailed management is required.

The degree of risk is determined by managing the level of risk in each zone at the time of independent movement at the level P, and setting the outermost frame at the level P =
0, the circle closest to the center is managed as the highest level n, divided into n stages. In addition, when the revolving superstructure 1 is revolving, when the boom 2 is moving, when the arm 3 is moving, and when a plurality of these are moving, there is a risk of the level P. The degree of danger increases in accordance with the operation. Thus, the level P is corrected for the first single level. As this correction, the value of the initial level P is multiplied by a certain numerical value Q (however, a number equal to or more than 1), and the risk level (level P) to be determined is determined.
Is calculated, or a certain addition value Q is specially added and calculated.

The object detection / distance calculation program 9b detects that the reception detection circuit 16 detects a reception signal and outputs an interrupt signal to the MP.
It is started by the MPU 10 when it is sent to U10.
The program 9b includes the receiving sensors 17a, 17b, 1
7c is time-divisionally switched to obtain front / rear, left / right position data signals from these receiving sensors sequentially, and based on the distance between each receiving sensor and the distance to the receiving object, the hydraulic pressure is calculated by a so-called trigonometric operation. The position of the detection target 19 (employee side alarm device) with the center O (center of rotation) of the shovel 20 as the origin O is calculated. In addition, an identification signal for identifying an object is generated as described later, and the identification signal is stored in the memory 9. Thereafter, the MPU 10 activates and executes the risk determination program 9c.

An example of the calculation of the distance by the trigonometric method will be described with reference to FIG.
Taking as an example the case in front of 0, a known distance L ₁ between the receiving sensors 17a and 17b, the distance L ₂ between the receiving sensor 17a and the detection object 19 and the receiving sensor 17b and the detection target 19 Is measured and the distance L ₃ is measured.
When three sides of a triangle formed by 7a, 17b and the detection target 19 are known, ∠α, which is an angle formed by the detection target 19 and the reception sensors 17a to 17b, is calculated. Also, since the internal angle of the receiving sensor 17a among the internal angles of the triangle formed by the sensor is known as ∠β = 30 degrees, the rotation center (origin O) of the detection target 19 and the excavator 20
Is calculated, and the coordinates (X, X) of the detection target 19 in the case of having the origin O of the coordinates at the rotation center are calculated.
Y) is calculated. The object detection / distance calculation program 9b stores the calculated coordinates (X, Y) in the memory 9.

The risk determination program 9c is started, and M
When executed by the PU 10, the MPU 10 obtains the current coordinates Xo, Yo of the center of each potential zone periodically calculated by the center position calculation program 9a with reference to the potential data table 9e. Then, based on this and the coordinates (X, Y) calculated by the target detection / distance calculation program 9b, each potential zone PA,
The distance Lo between the center position of PB and PD and the detection target 19 is calculated. Next, the potential data table 9e determines which range of the circle this distance Lo is viewed from the center side.
Array rn / Pn, dn-1 / Pn-1 of, ···, r ₁ / P
₁ , r ₀ / P _0, which are obtained by comparing the sizes, and the degree of risk (level Pi) corresponding to the circle is determined for each zone P
Obtain for A, PB, PC, PD. Then, the coordinates and the degree of danger (the value of the level P) are set as the target storage area 91 corresponding to the identification information of the monitoring target table 9f (FIG. 1
2). The identification information is generated by the target detection / distance calculation program 9b according to the detection target. For the potential zone PD, the detection distance L to the detection target 19 is used as it is.

After the above registration, the risk determination program 9
c is a predetermined range centered on the registered coordinates (whether or not there is any already stored as a detection target) by sequentially referring to the contents of the target storage area 91 of the monitoring target table 9f (this range is This is a determination range of the same object, which is appropriately determined according to the moving speed of the work machine, etc.
It is determined whether or not they are the same detection target 19. If there is, the registered object and the newly registered object are determined to be the same object, and the risk level of the registered object 19 is read and the level P is determined. Thus, the risk (P
= Potential value) is increased with respect to the past. When the degree of risk is the same or increasing, the information of the flag "1" is added to the data of the coordinate value newly registered for the monitoring target and stored. For those for which the flag “1” has been set, the determination of the degree of danger is performed with priority thereafter. If the degree of risk has dropped to a predetermined level or more, for example, three or more ranks, information of the flag “0” is added to the newly registered coordinate value data. Then, the coordinates and danger of the registered detection target are deleted. At this time, if there is no registered detection target within the same target determination range, the information of the flag “0” is added to the newly registered coordinate value data and registered. The coordinate data with the flag “0” set in this way is deleted at a suitable timing or at the next monitoring before registering a new target, and is removed from the monitoring target.

This eliminates noise and the like. That is, only the data with the same or increased risk becomes a monitoring target, is left in the monitoring target table 9f, and the others are deleted. In the risk determination when the monitoring target exists with reference to the monitoring target table 9f, when any one of the revolving unit 1, the boom 2, the arm 3, and the bucket 4 of the work machine is being controlled, the control is being performed. Priority is given to the potential zones of the objects, and when each is under control, priority is given to the bucket 4, the arm 3, the boom 2, and the revolving unit 1 in this order.

If the risk potential value increases as a result of this determination, it remains in the monitoring target table 9f of the memory 9 as a monitoring target. After that, the MPU 10 starts the alarm processing program 9d. When the MPU 10 activates the alarm processing program 9d, the MPU 1 sequentially obtains the value of the level P for the target with the flag “1” by referring to the target storage area 91 of the monitoring target table 9f. Then, the following processing is performed on each of the sequentially obtained level P values.

As the operation, for the sake of simplicity, first, the contents of an alarm when no object identification is performed will be described. This includes, for example, zones PA, PB, PC,
Assuming that the level P of the PD is set to each of seven levels, when only one of the revolving superstructure 1, the boom 2, the arm 3, and the bucket 4 is operating alone, each of the levels from "0" to "7" When the monitoring target enters any of the monitoring targets, when the potential value is being monitored, only the alarm buzzer is generated for the value of the level P corresponding to the potential zones “0” to “1”, and the potential zone “1” is set. At the level corresponding to "2" to "2", the sound "Dangerous" is generated. At the level corresponding to the potential zone "2" to "3", "Workers are dangerous, so please stay away.""Dangerous !, dangerous!" At the level of zone "3" to "4", and "Dangerous !, evacuate!" At the level of potential zone "4" to "5". Slowing the operation of the work machine at the level of the potential zone "5" to "6", at the level of the potential zone "6""7" or the like stops the operation of the work machine. When the revolving superstructure 1, the boom 2, the arm 3, and the bucket 4 are operating in combination,
In the relationship between the operation and the level P for the zones PA, PB, PC, and PD, for example, one potential zone “0” to “1” is “danger !, danger!” And the potential zone “1”. From "2" to "Dangerous !, save!", Its potential zone "2"
From “3” to “3”, the operation speed of the work machine is reduced, and from “3” to “4”, the operation of the work machine is stopped. The selection of the alarm content as a result of the target identification will be described later. However, the above various alarm messages are used to obtain the alarm message search information M (see column 92 in FIG. 12) of the monitoring target table 9f. A value of level P corresponding to each message is selected according to the degree of risk, and is stored in the monitoring target table 9f.

In the above description, the relationship between the virtual risk potential zones is fixed. However, when the excavator 20 moves forward and backward and the front attachment is working, as shown in FIG. Alternatively, the center position of each circle may be shifted in the working direction to form a simple multiple circle in which the potential zone is widened in the working direction. Also,
The calculation may be performed by shifting the center of the concentric circle of each potential zone in the movement direction and setting the center in advance at a predicted position to be reached. This state is indicated by a solid-line circle with respect to the dotted line in FIG.

The above description of the virtual risk potential zone is an example, and the size and number of circles set as the potential zone can correspond to the combined operation of the work machine. In particular, when the attachment is replaced, it is preferable to prepare a basic graphic pattern according to the work member to be replaced. The manner of setting the risk of each virtual risk potential zone can be determined according to a so-called exponential curve that increases logarithmically as shown in FIG. 8, and the zone density is also set according to the work machine. do it. In the above case, the case where the detection target moves in the virtual risk potential zone is taken as an example, but the risk is determined by the speed at which the detection target increases the risk by taking the virtual risk potential zone at high density. May be determined. This can be achieved by collecting the increase rate of the risk as a function of time.

Next, a configuration for generating an appropriate alarm in accordance with a case where the detection target 19 is a worker or a general person, a specific obstacle, equipment, or the like and a target identification process will be described with reference to FIG. Here, the hydraulic excavator 20 is a vehicle on which the main station is mounted, and plays a role of the main station ultrasonic transmitting and receiving device. 20a, 20b, ... 20n
Is a slave ultrasonic transmission / reception device (hereinafter referred to as a slave transmission / reception device) attached to a detection target 19 such as a worker or a general person, a specific obstacle, or equipment serving as a slave to the hydraulic excavator 20 serving as a master.

Each of the receiving sensors 17a, 17b, 17c mounted on the hydraulic excavator 20 is an ultrasonic transceiver 170a, 170b,.
.. 170n. Ultrasonic generation horn 18
The transmission frequencies of a, 18b, 18c, and 18d are, for example,
Its center frequency is 30 kHz, which generates ultrasound in a narrow band. Ultrasonic transceiver 170a, 170
, 170n have a center frequency of 10 kHz,
It has the characteristic of a narrow band center frequency that does not overlap with other ultrasonic transceivers, such as 14 kHz, 18 kHz,..., And transmits and receives ultrasonic waves at its natural frequency.

160n, 160a, 160b,.
It is a narrow band filter having a center frequency corresponding to each natural frequency corresponding to each of the ultrasonic transceivers 170a, 170b,... 170n, and is provided in the reception detection circuit 16. 161a, 161b,... 16
1n is an ultrasonic transceiver 170a, 170b,... 1
70n is a distance data generation circuit provided in the reception detection circuit 16 corresponding to 70n. Then, the transmitting circuit 18 drives the ultrasonic wave generating horns 18a, 18b, 18c, 18d, and here, the ultrasonic transmitter / receivers 170a, 170a, 1
.. 170n are selected and driven.

The arithmetic control unit 6 has, for example, 0.1 to 0.3
A transmitter (transmitter / receiver) selection signal is transmitted to the transmission circuit 18 at a predetermined measurement cycle of about sec.
The selection signal is transmitted to the ultrasonic generation horns 18a, 18b, 18c,
.. 161n after a predetermined time after driving the transmission circuit 18 as 18d.
Are sequentially accessed to collect time data (measured time value data) representing the distance to the object, and store it in the memory 9.
Are sequentially stored in the storage areas allocated to the respective distance data generating circuits. The sampling of the time data is performed at a timing before driving the transmission circuit 18 next.

The alarm unit 7 includes a voice synthesizing circuit 7a and an amplifier 7
b and a speaker 7c. The voice synthesizing circuit 7a receives a control signal from the MPU 10, accesses a predetermined address of an internal ROM of the voice synthesizing circuit 7a according to the content of the control signal, generates a necessary voice signal, and adds the control signal to the amplifier 7c. Is generated from the speaker 7c.

.. Slave stations 20a, 20b,.
0n has the same internal configuration except that the transmission frequencies to the master station are different from each other.
The internal configuration will be described using a, and other components will be omitted. The slave station transmitting / receiving device 20a is usually mounted on a worker or an obstacle, and is a small device such as a business card. This device has an ultrasonic receiver 21 having a narrow band characteristic for receiving an ultrasonic wave having a center frequency of 30 kHz, and a center frequency of 10 kHz uniquely assigned to the slave transceiver device 20 a (other slave transceiver devices have other center frequencies). ), And receives signals of the ultrasonic receiver 21 and the ultrasonic transmitter / receiver 22 via the filter 23 having a narrow band-pass having a center frequency of 30 kHz and 10 kHz. Control circuit 24,
A buzzer (alarm) 25 driven by the control circuit 24 in accordance with a received signal from the ultrasonic transceiver 22 is provided.

Here, the control circuit 24 has therein a receiver for amplifying and detecting a received ultrasonic electric conversion signal and performing waveform shaping, and a pulser for pulse-driving the ultrasonic transmitter / receiver. This circuit drives the ultrasonic transceiver 22 via the preceding pulser when a signal of a predetermined level or more is received by the receiver from one of the ultrasonic receiver 21 and the ultrasonic transceiver 22, and drives the ultrasonic transceiver 22 at the main station. Control is performed to generate a response transmission signal on the side of a certain vehicle using ultrasonic waves having a natural frequency assigned to the vehicle. When a signal of a predetermined level or more is received from the ultrasonic transmitter / receiver 22 by the receiver, the alarm device 25 is driven at a constant period for a predetermined period.

Since the ultrasonic transmission wave in the above case is driven by the pulsar by the pulsar, the reception wave on the receiving side is close to a sine wave centered on the wavelength of the assigned natural frequency. Is obtained. Therefore, on the ultrasonic receiving side of the slave station transmitting and receiving apparatus, the received wave signal is amplified and detected, and the waveform is shaped to obtain a detection signal and drive the pulser. On the other hand, the ultrasonic receiving side of the main station transmitting and receiving apparatus further detects the peak from the amplified and detected signal. Thereby, the distance data generation circuits 161a, 161
.. 161n measure the distance to the object by converting the distance to the time value.

First, distance measurement circuits 161a, 161b,...
161n will be described as a representative of the distance data generation circuit 161a. Distance data generation circuit 161a shown in FIG.
Are provided corresponding to the slave station transmitting / receiving device 20a.
The natural frequency of the ultrasonic transceiver 22 of the slave transceiver device 20a is 10 kHz. The center frequency (assigned natural frequency) of the ultrasonic transceiver 170a connected to the end of the distance data generation circuit 161a is 10 kHz as described above. This likewise has a center frequency of 10
receiving circuit 162 through a narrow band filter 160a
Is input to

The received ultrasonic electric signal is amplified and detected by the receiving circuit 162, input to a buffer circuit (buffer amplifier) 163, passes through a gate circuit 164, and receives a gate pulse as shown in FIG. The echo signal R is extracted as a target echo signal R (see FIG. 9B) at the timing and width of the signal G, and is sent to the peak hold circuit 165. Here, the gate circuit 164 includes, for example, an analog switch or the like. Note that S is a drive pulse when the ultrasonic wave generating horns 18a, 18b, 18c, and 18d are driven. This drive pulse is input to the time measurement circuit 167 as the transmission reference signal S and becomes a time count start signal.

Here, by applying a gate G, FIG.
1 (b), only the analog echo signal between the gates is extracted, and the peak hold circuit 16
At 5, the peak value is retained. Note that the setting position of the gate G corresponds to the width in which the received wave can be extracted even if the slave station transmitting / receiving apparatus 20a is within the monitoring range of the master station and the slave station transmitting / receiving apparatus 20a moves to some extent. This is set to remove as much noise as possible including unnecessary echoes that occur before and after. Therefore, if the gate G has a large width, this may be fixed. However, when the slave station transmitting / receiving device 20a approaches, the gate G is set to have such a width that noise can be removed accordingly, and the gate G is set for the next reception. The tracking may be calculated and set to move to a range where waves can be received.

Meanwhile, the count value of the distance data generation circuit corresponding to the slave station transmitting / receiving apparatus that does not generate a reception signal is larger than the value set at the trailing edge of the gate G. Therefore, when a certain distance data generation circuit has a value larger than the value set at the trailing edge of the gate G,
This means that there is no corresponding received signal from the slave transmission / reception device. That is, by determining whether or not the count value of the distance data generation circuit is greater than the value set at the trailing edge of the gate G, it is possible to determine whether the slave transceiver device has entered the monitoring area or not. Thus, it is possible to determine whether or not the target slave station transmitting / receiving apparatus is in a monitoring state. Therefore, the setting position of the gate G may be set to a position sufficient to monitor each slave station transmitting / receiving device, and may be different from each other in accordance with the slave station transmitting / receiving device. By setting a maximum value that can be monitored by all slave transmission / reception devices,
With the count value exceeding this, it is possible to determine that there is no reception signal from the slave transmission / reception device, and to determine the presence or absence of the monitoring state. In such a case, the setting of the gate G becomes unnecessary.

Now, returning to the original state, the voltage Vr of the received wave R from the slave transmitting / receiving apparatus 161a is held by the peak hold circuit 165, and the output voltage value Vr of the held value is then compared with the comparator 166. Is input to The other input of the comparator 166 is connected to the gate circuit 16.
4 (b), which is output from FIG. 4, and the peak values are compared between them. Therefore, the most recent peak value obtained from the gate circuit 164 only when exceeding the peak value P ₁ before the already held, the comparator 166 generates an output.
Therefore, to detect it as a received wave when a higher peak value P ₂ came. Therefore, it is possible to set the threshold TH with respect to earlier peak value P ₁ to be held taken to detect the position of the received wave signal R when the threshold to that eliminates noise. This is because, generally, the negative waveform detected from the received wave is also inverted to the positive side, and a peak higher than the first peak comes later. Therefore, this detection output is transmitted to the time measurement circuit 16 next.
7 and used as a stop signal for time measurement. It should be noted that depending on the reception waveform, it is often better to set a predetermined level threshold and to detect the reception signal at the time when the threshold is exceeded, rather than performing peak detection. Therefore, in such a case, it is sufficient to simply set a threshold and detect it as reception of a received signal from the slave station transmitting / receiving apparatus when the threshold is exceeded, without using the peak detection circuit.

The time measurement circuit 167 receives a transmission pulse for driving the ultrasonic wave generating horns 18a, 18b, 18c and 18d from the transmission circuit 18 and starts with a reference signal S synchronized with the transmission pulse, and is provided inside or outside. The clock supplied from the clock generation circuit 168 is counted and stopped by the output of the comparator 166. The measurement value of this time measurement circuit 167 is MPU
The data is stored in the storage area of the memory 9 corresponding to the distance data generation circuit 161a via the interface 14 by the interface 10. In this way, the distance data generation circuits 161a, 161b,.
The measured value of the 161n time measuring circuit 167 is stored in the memory 9
Are stored in the areas assigned to the respective distance data generation circuits 161a, 161b,... 161n. This storage area information is stored in the ultrasonic transceiver 17.
., 170n are used as information for specifying individual ultrasonic transceivers received from the slave station, and further, are used as slave station transceivers 20a, 20b,.
It also becomes information for identifying 20n. The memory 9 has
Each distance data generation circuit 161a, 161b,... 16
An area for storing the measurement value of the 1n time measurement circuit 167 is provided corresponding to each of the reception sensors 17a, 17b, and 17c. The individual ultrasonic transceivers (170a, 170b,...) Of the master station corresponding to the eigenfrequency assigned to the slave transmitting / receiving apparatus (object) determine what the object is.
170n), the calculation control unit 6
May be determined.

The arithmetic and control unit 6 activates the object detection / distance calculation program 9b and activates each of the receiving sensors 17a, 17b, 1
.. 161n of the memory 9 provided corresponding to the memory 7c, the measured value is not zero (if there is a minimum count value due to noise, it is equal to or greater than the count value). The time measurement value is obtained from the area where is stored. Further, the address value of the area where the time value is stored is stored in order to generate the target identification information. By these, the ultrasonic transceivers 170a, 170
b,... 170n, information for selecting an ultrasonic transceiver to be driven, and slave station transmitting / receiving apparatuses 20a, 20b,.
20n, and the identification information of the slave transmission / reception device to be managed that issues an alarm. The generated identification information is stored in a predetermined area of the memory 9. Thereafter, the risk determination program 9c is started.

The risk determination program 9c refers to the identification information stored in a predetermined area of the memory 9 and searches the monitoring target table 9f shown in FIG. 12 from the identification information of the slave transmission / reception device to be managed. As described above, it is determined whether or not there is an alarm target and management is performed. In the monitoring target table 9f, a search column 90 for identification information is provided in the first column, and a target storage area 91 is provided next to the search column 90.
Here, a plurality of coordinates (x, y), a level P, and a flag F of the detection target can be stored in the form of (x, y) / P / F. The position of the table for storing the coordinates (x, y) of the target, the level P, and the flag F may be separately arranged, and a pointer indicating the position may be stored in the target storage area 91. The next column 92 stores the level P indicating the degree of danger and the alarm message search information M corresponding thereto in a pair form, and stores the alarm message search information M (for example, M ₁ , M ₂ ,...) From the level P.・) The last column 93 is the alert message search information M
A pointer indicating the head address of the search table 94 from which the actual alarm information is obtained is stored.

As described above, when there is an object to be warned, the MPU 10 starts the warning processing program 9d. By executing the alarm processing program 9d, the MPU 10 searches the monitoring target table 9f according to the identification information of the detection target, refers to the target storage area 91, and has the detection target stored therein. It is determined whether or not there is an object to be detected, and when the flag is “1”, it is detected as a monitoring object and the value of the level P is obtained. Then, the alarm message search information M corresponding to the level P is obtained from the column 92, and then the message table 94 is searched from the information in the column 93 to obtain an information column (eg, a ₁ , a ₂₎ about the actual alarm information. , ...). Then, the obtained information sequence is sequentially transmitted to the alarm unit 7.

The contents of the alarm include, for example, when the worker to be identified has a certain danger level “0”,
Without alarm. At the danger level "1", only the alarm buzzer is generated, at the danger level "2", a "dangerous" sound is generated, and at the danger level "3", "Mr. XX is dangerous. At the danger level "4", "Mr. dangerous", and at the danger level "5", the work machine is stopped. And so on. It should be noted that the name “XX” of Mr. XX is stored in the table 94 in correspondence with the identification information or obtained from a separate search table and added as audio information.

When a plurality of detection targets are stored in the monitoring target table 9f, such an alarm is generated in a serial manner. A determination process for generating an alarm may be added.

As described above, in the embodiment, the slave transmission / reception device adopts a transmission / reception mode. However, the ultrasonic transceiver for transmitting / receiving at the natural frequency assigned to each slave transmission / reception device is a transmission-only ultrasonic transceiver. It may be a sender. Similarly, the ultrasonic transmitter / receiver of the natural frequency of the main station transmission / reception device may be simply for reception only. This is because the master station can individually receive the received signal and monitor the alarm target. When one of the slave transmission / reception devices exceeds the risk level “0” and enters the risk monitoring level, the master transmission / reception device monitors the individual monitoring state for transmission / reception with the slave transmission / reception device and the slave transmission / reception device. The monitoring level and the monitoring level may be alternately performed. The slave transmission / reception device may be mounted not only on the workers and various obstacles and the equipment described in the embodiment but also on persons and objects requiring monitoring. Even in this case, monitoring can be performed according to each risk level.

In the example of the circuit shown in FIG. 10, only the reception signal in a certain range is extracted by applying the gate G. This is to eliminate noise and unnecessary reception signals. Since the time measurement circuit may also have a count value due to noise, such a noise-like count value is naturally excluded. Apart from such noise measurement values, it is usually possible to detect only a certain target range by determining a dangerous level when the count value falls below a certain value. By entering, unnecessary ultrasonic reflection from an object can be eliminated. by the way,
In the embodiment, the distance data generation circuit for measuring the distance by time measurement is provided for each ultrasonic transmitter / receiver that transmits and receives at an individual frequency. However, this is a common time measurement as long as the time measurement result can be obtained independently. It may be provided as a circuit. Further, in the above embodiment, the ultrasonic wave is used as a signal for transmission and reception, but it is a matter of course that a radio signal may be used. When using a radio signal such as a microwave, the frequency itself may be used as a transmission signal code specific to the slave station, or a carrier signal of a predetermined frequency may be modulated using a code signal assigned to the slave station. , And the master station may decode the code by demodulating it.

[0049]

As can be understood from the above description, according to the present invention, in order to identify and detect an object, the work machine is used as a master station, and from the time when the master station transmits to the time when the master station receives it. In addition to managing the distance with the time, and receiving the signal from the transmitter to which the signal unique to each slave is assigned from the slave, the distance from multiple objects can be measured simultaneously by time measurement, Even if there are a plurality of slave transmission / reception devices, the alarm target can be individually recognized. Furthermore, a plurality of virtual risk potential zones composed of multiple circles are set around the tip of the arm of the work machine, and when one of the circles contains a monitoring target, a circle with a low risk to a circle with a high risk is set. Since the monitoring target is detected when the target has moved to and an alarm is sounded,
It is hard to be affected by noise or the like generated at random, and can issue an alarm more safely. as a result,
It is possible to generate an alarm depending on the target, and it is possible to improve the safety of the work machine and increase the work efficiency.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an embodiment in which the alarm system for a working machine according to the present invention is applied to a hydraulic shovel.

FIG. 2 is an explanatory diagram of an overall configuration of a hydraulic shovel.

FIG. 3 is an explanatory view of a mounting relationship between the receiving sensor and the ultrasonic generating horn.

FIG. 4 is an explanatory diagram of the virtual risk potential zone.

FIG. 5 is an explanatory diagram of a potential data table.

FIG. 6 is an explanatory diagram of a virtual risk potential zone set according to the operation of the excavator.

FIG. 7 is an explanatory diagram of a virtual risk potential zone set by estimating a destination in a working state.

FIG. 8 is an explanatory diagram of a risk setting function of a virtual risk potential zone.

FIG. 9 is a block diagram of a transmitting / receiving system for identifying a detection target in the embodiment shown in FIG. 1;

FIG. 10 is a block diagram of a distance data generation circuit that calculates a distance to an object.

FIG. 11 is an explanatory diagram for explaining an operation of the distance data generation circuit.

FIG. 12 is an explanatory diagram of a monitoring target table.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Top revolving superstructure, 2 ... Boom, 3 ... Arm, 4 ... Bucket, 5 ... Traveling body, 6 ... Operation control part, 7 ... Warning part, 8 ... Drive control part, 9 ... Memory, 9a ... Center position calculation program 9b: Target detection / distance calculation program, 9c: Danger level judgment program, 9d: Warning processing program, 9E: Monitoring target table, 9f: Potential pattern storage area, 10: Microprocessor (MPU), 11: Video RAM ( V-RAM), 12 display, 13 bus, 14 interface, 15 selector, 16 reception detection circuit, 20 hydraulic excavator, 17a, 17b, 17c reception sensor, 18a, 18b, 18d, 18e super Sound wave generating horn, 20: hydraulic excavator, 170a, 170b, 170n: ultrasonic transmitter / receiver, 161a, 161b, 1 1n ... distance data generating circuit, 162 ... reception circuit, 163 ... buffer circuit (buffer amplifier), 164 ... gate circuit, 165 ... peak hold circuit.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-2-176589 (JP, A) JP-A-1-271534 (JP, A) JP-A-1-303597 (JP, A) (58) Field (Int.Cl. ⁶ , DB name) G08B 19/00-21/00 B25J 19/06 B66C 23/88 E02F 9/24-9/28

Claims (6)

(57) [Claims] 1. A master station mounted on a work machine having an arm, wherein a master station transmitter, a master station receiver, and a predetermined signal of the master station receiver are received from transmission of a signal from the master station transmitter. A first transmission / reception device having a time measurement circuit for measuring time until a plurality of imaginary objects whose risk increases toward the inside formed by multiple circles having different radii on the plane around the tip of the arm. Potential zone setting means for setting a risk potential zone; position detecting means for obtaining the time value measured by the time measuring circuit to detect the position of the detection target with respect to the work machine; and detecting by the position detecting means. Determining means for determining whether the detected position is within any of the plurality of virtual risk potential zones, and alarm means for generating an alarm. The work machine that detects that the detection target has moved from a low risk zone to a high risk zone among the plurality of virtual risk potential zones according to a result and drives the alarm unit to generate an alarm. A control device mounted on a slave receiver that receives a signal from the master transmitter, a slave transmitter that generates the predetermined signal unique to the station, and the slave receiver are transmitted from the master transmitter. And a second transmitting / receiving device as a slave station having a control circuit for driving the slave station transmitter when receiving the signal of (i). 2. Each of the circles is a concentric circle, the arm is connected to the boom, and the potential zone setting means is imaginary around the tip of the arm and the connecting portion between the boom and the arm. The alarm system for a work machine according to claim 1, wherein a danger potential zone is set. 3. The master station transmitter is an ultrasonic transmitter having a first center frequency, and the master station receivers each have a second to (n + 1) th center frequency (where n is an integer of 2 or more). The first to n-th ultrasonic receivers, and the time measurement circuit is configured to perform processing from transmission of ultrasonic waves from the main station transmitter to reception of ultrasonic waves by one of the n main station receivers. The slave transmitter is an ultrasonic slave receiver that receives an ultrasonic wave from the master transmitter, and the slave transmitters are the first to n-th slave transmitters.
2. The alarm system for a work machine according to claim 1, wherein the ultrasonic transmitter transmits a transmission signal to the main receiver as a signal unique to the local station, using the same frequency as any one of the center frequencies of the ultrasonic waves. 4. A work machine has a revolving structure for supporting a boom, and a traveling structure provided below the revolving structure, wherein each circle is concentric, and an arm is connected to the boom, and Zone setting means, a tip portion of the arm,
The alarm for a work machine according to claim 1 or 2, wherein a virtual danger potential zone is set around each of the connecting portion between the boom and the arm and the connecting point between the boom and the swing body. system. 5. The alarm system for a work machine according to claim 1, wherein the center of each circle is set in accordance with the direction of movement or operation of the work machine. 6. The alarm system for a work machine according to claim 1, wherein the plurality of virtual risk potential zones to be set are selected according to an attachment mounted on the work machine.