JPH04140333A - Detection of obstruction for working vehicle - Google Patents

Abstract

PURPOSE:To permit safe, exact, and quick operations by a method in which obstructions around working machine are detected by a non-contact sensor, and on the basis of signals from the sensor, a controller is controlled, CONSTITUTION:Survey signals are sent out from non-contact sensors 10R and 10L provided on both ends of a counter weight 9 to develop a survey signal area 12. On the basis of signals generated when obstructions are present in the area 12, the condition of the obstructions is judged by the distance arithmetic function and judging function of a controller 11, and a safety distance is set up by outside input. When the obstructions become less than a set value, alarm signal to stop the operating machine is sent out. Operation can thus be discontinued by sending out alarm when the distance between obstructions and the machine is reduced during operation. Safe, exact, and quick operations on site can be secured.

Description

[Detailed Description of the Invention] Industrial Field of Application This invention automatically issues a warning when a work vehicle is in operation or when an obstacle approaches a dangerous side to an operating machine. This invention relates to an obstacle detection method that requires measures such as stopping the operation.

This will be explained by referring to a pull dozer and a hydraulic excavator, which are construction machines, as they are one of conventional technical work vehicles.

Among these machines, one dozer l shown in Figures 6 and 7 operates the dozer blade 3 attached to the front of the machine vertically with respect to the machine body, and at the same time moves the branch body back and forth to control the dozer blade 3. The cutting edge provided at the bottom of the machine is used for excavating, pushing up, and leveling the ground surface. In addition, the hydraulic excavator shown in Fig. 9 in the 8th cabinet has an upper rotating body 8 rotatably provided above the lower traveling body 7 via a swing bearing, and a boom 4, an arm 5, a packet 6, etc. The working device consisting of is supported to be vertically movable, and the cutting edge of the packet 6 is used to mainly excavate and scoop up underground, and the upper revolving body is rotated as appropriate to load the excavated earth and sand into a transport vehicle, and to load the excavated earth and sand into a transport vehicle. They are piled up and backfilled in place, and if necessary, the lower traveling body 7 is operated to move back and forth, change direction, etc.

In this way, bulldozers and hydraulic excavators use their self-bladed blades to move to unspecified locations or rotate to perform work, and work vehicles similar to these are now indispensable at all work sites. As a result, work vehicles have come to completely perform labor-intensive work that used to be done manually. Therefore, at a single work site consisting of many types of work, the current situation is that people and work vehicles or other work vehicles work simultaneously and in a mixed manner.

Although it is natural that the driver's seat of such a work vehicle is usually located at a location and shape where the operation of the work equipment is most visible and safest for the work, For example, when using the bulldozer 1 shown in Figure 6 to level the ground with the dozer blade 3 while moving backwards, there is a blind spot in the field of view from the driver's seat. If workers or other work vehicles enter nearby, or if the driver does not notice other obstacles on the ground, or if the hydraulic excavator 2 shown in Figure 8
When the packet 6 is loaded with excavated soil and the upper revolving body 8 is rotated to load it onto a transport vehicle such as a dump truck, the counterweight 9, which is not attached to the working equipment or the rear of the upper revolving body 8, is used as described above. Unexpected accidents may occur if workers or other work vehicles enter the turning radius, or if there are obstacles on the ground.

Conventionally, various measures have been taken to avoid this type of accident, and one example is the installation of a sensor 20 at the rear of the bulldozer I shown in Figure 6.7, and the hydraulic In the excavator 2, sensors 2 are installed on both sides of the counterweight 9.
1 is fixed. The sensor 20.21 has a predetermined angle,
A search signal is sent to a range of directions, and if there is an obstacle within that range, the reflected wave is detected, and a dedicated controller calculates the distance to the obstacle from the arrival time of the reflected wave. When the distance reaches a preset value, the controller issues a signal and activates a warning device to prevent an accident from occurring.

In general, the safe range of the set distance for activating the alarm means is as follows: Taking a bulldozer as an example, in the forward and backward direction of movement shown in FIG. 7, the working movement length is Lm.
Moving forward and backward, respectively, length direction safety dimension E =
15 m, and in the middle direction, if the working material is Wm, a safety dimension w = 2 m or more in the width direction must be provided on both the left and right sides, and, taking a hydraulic excavator as an example, as shown in Fig. Although it depends on whether the object is located at the front or rear of the upper revolving structure 8, the radial safety dimension r= is either the turning radius Rαm of the working device or the rear end turning radius Rcm.
It is recommended that the distance be increased by at least 2m.

Problems to be Solved by the Invention In conventional alarm devices, as described above, the distance from the obstacle at which the alarm starts to operate is set with a margin in advance, and the alarm device is activated during work. Operation of the aircraft in that direction shall then be discontinued, but otherwise special care and measures must be taken to ensure careful aircraft operation. On the other hand, in recent actual work,
Even in confined spaces where obstacles exist within the safety setting range of the separation distances mentioned above, it is often necessary to carry out tasks in a confined space. Even though the device is in operation, you will have to ignore it and proceed with the work, or you will have to temporarily stop the activation of the alarm device and continue with the work. The result will be unsatisfactory.

The present invention compensates for the shortcomings of the prior art, detects only the occurrence of obstacles that gradually approach the operating range of the aircraft, and activates the warning means, without providing a large extra safety margin. The task is to propose a method that can perform construction work quickly and reliably.

Means for Solving the Problems In order to achieve the above-mentioned problems, the present invention provides a detection method having the following configuration. In other words, a search signal is transmitted in a direction and range where other obstacles may approach due to the operation of the airframe, and the reflected waves of the search signal from obstacles within that range are detected. A contact sensor is installed on the aircraft.

) A calculation function that calculates the separation distance between the two aircraft and an obstacle based on the signals from the non-contact sensor, and determines whether the separation distance gradually increases, gradually decreases, or remains constant over time. or, if necessary,
It also has a memory function that allows you to preset the safe separation distance between the aircraft and obstacles using external input, and stores the set value. A controller is provided which outputs a processed signal when it is determined that the value is below the value or a preset value and is in a gradually decreasing state.

c) A warning means is provided, such as an alarm device that emits a warning sound in response to a processed signal from the controller, or an operation canceling device that automatically cancels the operation in the direction in which the separation distance gradually decreases using the operating device for operating the aircraft.

Operation The aircraft equipped with a non-contact sensor is activated by the operating device,
Alternatively, even if an obstacle is near the aircraft, if the distance from the obstacle gradually decreases and does not fall within a preset distance, the controller will send a processing signal to start the activation of the warning means. Therefore, safety can be maintained simply by setting the above-mentioned separation distance setting value slightly beyond the minimum danger range in which the aircraft operates. In addition, it is possible to detect when a new obstacle enters the machine from the middle, and if there is a worker or other obstacle relatively close to the aircraft. Even when there is an obstacle such as a work vehicle, the warning means is activated when the distance from the obstacle gradually decreases from outside the minimum danger range, that is, it approaches, or when it reaches the minimum danger range.

Embodiment As an embodiment of the present invention, the structure and operation of a hydraulic excavator will be explained with reference to FIGS. 1 to 5. In addition, in FIGS. 1 to 5, the same parts as in FIGS. 8 and 9 are given the same reference numerals, and the explanation thereof will be omitted.

In the figure, IOR and IOL transmit exploration signals using non-contact sensors on the right and left sides provided at both ends of the counterweight 9, and as shown in FIGS. When 8 turns to perform work, the search signal area 12 is in the direction of a dangerous area that is likely to become a blind spot for the driver and into which ground workers or other work vehicles may inadvertently enter. As you expand (it is fixed).

These non-contact sensors IOR and IOL have obstacles 13 in FIG. 3, such as workers on the ground, other work vehicles, etc., or barriers 14 shown in FIG. 4, in their exploration signal areas 12. Then, the reflected wave of the exploration signal is detected,
A signal is input to the controller 1) provided in the driver's cab 15.

The controller 1) has a separation distance calculation function that calculates the distance between the aircraft and the obstacle 13 or barrier 14 based on the time difference between the exploration signal that is the signal from the non-contact sensor 10R1)0L and its reflected wave; A discrimination function that determines whether the separation distance gradually increases, gradually decreases, or remains constant over time, that is, whether it is approaching, receding, or is relatively stationary, or if necessary, a specific safety separation. It also has a function to store the setting value from the means for inputting and setting the distance arbitrarily from the outside, and the value obtained by the separation distance calculation function is less than the predetermined safe separation distance or the stored setting value. , when the above discrimination function determines that the state is gradually decreasing, the g-axis device or! 1) It has a function of transmitting a processing signal that activates a warning means such as an operation release device that automatically stops operation of an operation device that operates the aircraft in a direction in which the separation distance gradually decreases. . Although not shown, the 7-alarm device referred to here refers to conventional technology such as buzzers, warning lamps, chimes, etc., and the operation release device refers to 1. For example, when the actuation operation system is a hydraulic pilot type, the This refers to similar conventional technology, such as temporarily connecting the pipe line leading to the pilot oil chamber on the side to the inside of the tank and returning the spool of the oil switching valve, which was operated by pilot oil pressure, to the neutral position. Next, what about the controller 1) when the relative distance between the aircraft and the obstacle changes? Briefly explaining the IIi function based on the block diagram of FIG. 5, the condition for the controller to output the above-mentioned processed signal instructing the warning means to operate is that the signal from the non-contact sensor is input to the controller. This is when the separation distance calculated by the separation distance calculation unit is smaller than the set safe separation distance, and the discrimination function unit determines that the separation distance is gradually decreasing.

The obstacle detection method of the present invention having the above configuration and functions will be explained.

Assuming that the minimum separation distance that becomes the rear end turning radius due to the turning of the counterweight 9 in FIG. 3 is 16, if there is an obstacle in this range and the turning operation is performed, an accident will occur. Now, an obstacle 13, for example, an auxiliary worker, is located in the exploration signal area 12 on the non-contact sensor IOR side at positions α, b, c.
, d, 4°f,) gradually approaching the minimum separation distance IW16, in the prior art,
For example, when the obstacle 13 is at position α or b, regardless of whether it is moving or stationary, if the sensor determines that it is an obstacle, the warning means is immediately activated. 1. Originally, positions α and b are far away from the minimum separation distance 16, and the obstacle 13 crosses positions α, b, etc., and further moves to positions c, d, e, f.
, it is dangerous to approach position A, and, on the other hand, there is no danger at all if it stops at an intermediate position or otherwise retreats towards position α. . Therefore, in such a case, in the present invention, the safe separation distance 1) is set at a position with more margin than the minimum separation distance 16.
17 is set and stored in the controller 1) (. Then, the obstacle 13 gradually approaches the aircraft, and the position f
However, as the separation distance decreases, the discrimination function of controller 1 determines that 1
A processing signal is output to the notification means, but if the approach is immediately stopped and the position is maintained or exited in the direction α of one position,
Since the output of the above-mentioned processed signal is stopped, there are problems such as in the conventional technology, it is difficult to detect when an obstacle other than the obstacle 13 intervenes from the middle, and an extra operating range of the warning means is provided. Points are resolved. In addition, is thing 13
Of course, when the distance 16 is within the minimum separation distance 16, a processed signal is output from the controller 1) to the warning means, regardless of the determination result of the determination function.

FIG. 4 is a plan view of the hydraulic excavator 2 excavating and loading work near and along the barrier 14. When the excavation position and direction of the hydraulic excavator 2 are in the related positions shown, is within the search signal area 12 of the non-contact sensor IOL on the left side, and in the case of the conventional technology, the warning means is activated continuously to issue a warning, so special work setups are required, and one aircraft and barrier 14 In contrast, in the present invention, a safety separation distance line 18 is set with a little margin relative to the minimum separation distance 16, so that it is impossible to detect it when another new obstacle enters during this period. (As a result, when the upper revolving body 8 turns to the right and the counterweight 9 approaches the barrier 14 by crossing the separation distance line 18, the alarm means is activated. Therefore, it is possible to accurately know the limit of the right rotation angle of the upper rotary body 8 of the hydraulic excavator 2 at this site, and use it to the best of your ability. is not activated, and in the meantime,
It is also possible to detect when other obstacles enter between the aircraft body and the barrier 14.

In addition, the non-contact sensor 10R, IOL in this example
In this example, a pair of detection signal areas 12 are installed on the left and right sides of the upper revolving structure 8 of the hydraulic excavator 2 so that the detection signal area 12 is provided diagonally behind the upper revolving body 8 of the hydraulic excavator 2.However, the installation position, direction, number, etc. are limited to this embodiment. Depending on the type of work machine, work site conditions, etc., for example, on the work equipment or in the front, rear, left, right direction of the machine, etc. It goes without saying that it is preferable to install non-contact sensors equipped with appropriate probe signals in appropriate numbers and positions.

Effects of the Invention The obstacle detection method of the present invention can be applied to work vehicles at sites where multiple work vehicles operate and move simultaneously, at narrow sites where work vehicles and workers coexist, or at sites where there are a wide variety of complex work types. Even if you have equipment for
Even if the separation distance between the machine or work equipment and the obstacle is relatively close, unless the machine (or work equipment) or the obstacle moves in a direction that gradually reduces this separation distance, the specified As long as the set range is secured, the warning means will not operate, so work operations can continue as usual, and if another unexpected obstacle suddenly enters the set range, it will not be detected. Of course, during work operations, it is possible to exceed the predetermined setting range (a range with a slight margin for the dangerous range due to the operation of the aircraft, work equipment, etc.) and cause harm to third parties, including workers, or people on the ground. When there is an operation on the work vehicle or the obstacle that gradually reduces the distance between it and an obstacle such as a structure, the warning means is activated immediately, so there is no extra margin like with conventional warning devices. When the warning device is activated by adding a warning device, or if it is unavoidable that work must be carried out with the warning device activated, special monitoring should be carried out to take into account the occurrence of new obstacles.
There are very few people who are forced to perform particularly difficult driving operations under guidance.

Therefore, according to the present invention, work can be carried out safely, reliably, and quickly even in work sites with complex work conditions as described above.

[Brief explanation of drawings]

Figures 1 to 4 are external views of a hydraulic excavator when the detection method according to the present invention is adopted. Figure 1 is a side view of the external appearance during excavation work, and Figure 2 is a plan view of Figure 1. Figure 3 is a plan view illustrating the operating situation of the present invention when a large or other work vehicle approaches from diagonally behind the hydraulic excavator, and Figure 4 is a plan view illustrating the operating situation of the present invention when a large or other work vehicle approaches from diagonally behind the hydraulic excavator. Plan view illustrating the operating situation of the present invention during work at the location, No. 5
FIG. 6 is a block diagram of an embodiment of the present invention, FIGS. 6 to 9 are diagrams showing the operation of a prior art 7-report device, FIG. 6 is a side view of the outside of a bulldozer during leveling, and FIG. Figure 6 is a plan view, and Figure 8 is a side view of the hydraulic excavator during excavation work.
The figure is a plan view of FIG. 8. 1...Buldozer......Hydraulic cylinder 3 Bell 9...Counterweight OR...
...Non-contact sensor (right side) OL...Non-contact sensor (left side) 1 .....Controller 2... ...Exploration signal area 3...・・・・・・Obstacle 4・・・・・・More than barrier

Claims (3)

[Claims] (1) Equipped with a non-contact sensor capable of transmitting an exploration signal in a predetermined direction around the aircraft and detecting the reflected wave of the exploration signal, and a controller that processes the signal from the non-contact sensor; The controller has a separation distance calculation function that calculates the separation distance between the aircraft and an obstacle from the relationship between the exploration signal of the non-contact sensor and the reflected wave, and whether the separation distance is gradually decreasing, gradually increasing, or maintained. A method for detecting an obstacle for a work vehicle, comprising: a determining function for determining whether there is an obstacle; and a function for outputting a processed signal when the determining function determines that the separation distance is gradually decreasing. (2) The controller includes a probe signal from a non-contact sensor,
A separation distance calculation function that calculates the separation distance between the aircraft and obstacles based on the relationship with the reflected waves, and a safe separation distance between the aircraft and obstacles can be preset by external input, and the set value can be set in advance. Claim 1, characterized in that it is equipped with a memory function for storing data, and a function for outputting a processed signal when the value calculated by the separation distance calculating function becomes equal to or less than a set value set in the memory function. 1) Obstacle detection method for a work vehicle as described in section 1). (3) According to claim (1) or (2), the processing signal output from the controller activates a warning means consisting of an alarm device or an operation release device. Obstacle detection method for work vehicles.