JPH08310788A - Height detecting method for handled object in cargo handling machine and device thereof - Google Patents

Abstract

PURPOSE: To detect the height of a handled object such as refuse at a high speed with high accuracy in a cargo handling machine such as a crane at a refuse incineration factory. CONSTITUTION: Multiple ultrasonic sensors 10a-10d are dispersedly fitted to face a handled object 2 on a cargo handling machine structural body 5 having a bucket 8 reciprocated toward the handled object 2 from above and moved above the handled object 2, and the ultrasonic sensors 10a-10d take detecting actions so that the occurrence timings of ultrasonic signals are staggered individually or in specific groups to prevent mutual interference by a sequence control means. The distances from the ultrasonic sensors 10a-10d to the handled object 2 are detected based on the measured values obtained by the ultrasonic sensors 10a-10d.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for detecting the height of an object to be handled in a cargo handling machine such as a bucket crane for a refuse incineration factory, a steel overhead crane, and an unloader.

[0002]

2. Description of the Related Art Generally, in a cargo handling machine such as a bucket crane or an unloader of this kind, a function capable of automatically detecting the height level of a cargo handling object is indispensable for automatic operation.

For example, an automatic operation of an overhead crane (bucket crane) in a garbage incineration plant will be described as an example. In the automatic operation of this overhead crane, after grasping the dust in the pit with a bucket, hoisting, traversing and running the bucket to move it to the hopper, open the bucket at a position directly above this hopper and put the dust in the hopper. Repeat the work of throwing in. At this time, due to the structure of the dust pit, the overhead crane is usually a high object of 30 m or more, so when going to grab the dust in the pit with a bucket, lower it at a high speed, and forcibly decelerate when the bucket approaches the dust pile. Control is performed to switch to low speed, stop the unwinding work at the same time as landing, and shift to gripping operation.

The background of such operation control is that when the bucket is unrolled at a high speed and landed on the dust pile and stopped at the same time, the amount of rope that suspends the bucket is reduced during deceleration control for stopping. , Which causes the rope to become entangled in the bucket, damaging the rope during hoisting,
This is because, in some cases, it may be cut.

However, in order to prevent such rope trouble, if the unwinding speed is reduced to a level at which the amount of rope payout does not get entangled with the bucket when the unwinding of the bucket is stopped, the cargo handling time is reduced. It takes too long and becomes unrealistic. That is, in the automatic operation of the overhead crane at the refuse incinerator, in addition to the work of loading the dust into the hopper, for example, the preparation for loading the dust, the leveling of the dust pile in the pit, etc. are all automatically repeated. But
This is because it is necessary to reduce the time of repeated work, that is, the cycle time as much as possible. If this cycle time is long, the amount of garbage handling per crane is limited, so it is necessary to take measures such as increasing the number of cranes or increasing the amount of one bucket to be gripped, which increases equipment costs. Will be invited.

[0006] Therefore, in order to make the crane equipment economical in the refuse incineration plant, it is extremely necessary to detect the height of the dust pile in the pit accurately and automatically from the background described above. It becomes an important factor.

From the above, in the conventional case, the load change point when the bucket is actually unwound and landed on the dust pile before the crane is operated and the load on the bucket is removed is taken as the height of the dust pile. A detection method for detecting is considered.

More specifically, the dust pit plane is divided into a plurality of areas to form addresses. For example, the traverse direction of the dust pits is divided into A to D and the traveling direction is divided into 1 to 20, and 4 × 20 =
The address is changed to 80, and first the crane position is A1.
After moving it to the ground, lower the bucket and measure the height of the dust pile at that address, then move the crane position to the A2 ground and measure the height of the dust pile at that address. Follow the same procedure below. This is a method of sequentially measuring up to address D20.

[0009]

According to the method of actually landing the bucket and measuring the level of the dust mountain in this manner, the level of the dust mountain is excellent in accuracy. Therefore, at the time of the measurement, the level of the dust mountain is measured. It can be said that it can be detected correctly, but it has the following drawbacks.

First, if the number of addresses is large, the measurement will take a long time. For example, in the above example of division, 80 addresses must be measured one after another. Here, even if the measurement time per address is about 3 minutes, it takes at least about 240 minutes = 4 hours as the measurement time for all the addresses. Depending on the scale of the incineration plant, the frequency of inputting the dust to the hopper is once every 5 to 20 minutes, depending on the scale of the incineration plant. Moving cranes over time should be avoided.

Secondly, if the time interval between the previous measurement time point and the current measurement time point is long, the dust mountain height level after measurement may be different from the actual height level, which is not always high accuracy. It may not be said that it is a different measurement method.
This is because when the dust pile height changes due to bucket loading after a certain time has passed after the previous dust pile height measurement, the correction value for calculating and correcting the dust pile height for each cargo handling does not necessarily match the actual value. This is not the case, and in reality, the trash pile may collapse. By the way, as a measure against the collapse of the trash pile, we are also using an automatic break-in operation so that the trash pile does not grow locally in the pit. However, during an operation prioritizing such a break-in operation, for example, during a dust carry-in preparation operation, an irregular dust mountain height is apt to occur, which easily causes a mountain collapse.

[0012] Here, in the automatic crane operation, at the address where the height of the dust pile is lower than the measured value as a result of the collapse of the dust pile, the low unwinding time of the bucket becomes long, resulting in a long cycle time. It is safe for the crane operation. However, at an address where the height of the dust pile becomes higher than the measured value, the bucket may plunge into the dust pile at a high speed before shifting to a low speed when the bucket is unwound. This causes rope trouble and is dangerous and must be avoided.

Therefore, in reality, in a large-scale refuse incineration plant, the height of the dust pile in the pit is visually checked by human eyes, and the dust pile height data is manually input. There is. Here, in the case of the visual method, since the deep pit is viewed from above, it is not possible to accurately measure the height of the dust mountain, and in order to avoid the rope trap, it is safer than the actual height of the dust mountain, that is, The reality is that the height of the trash pile above the actual value is recognized. This is a method that lacks accuracy and is not suitable for automatic operation.

[0014]

According to a first aspect of the present invention, there is provided a method for detecting the height of an object to be handled in a material handling machine, comprising a bucket which reciprocates from the sky to the object to be handled. A plurality of ultrasonic sensors are mounted on the moving cargo handling machine structure while being opposed to the cargo handling object while being dispersed, and these ultrasonic sensors are individually or individually grouped by a sequence control means. The detection operation is performed by shifting the generation timing of, and the distance from the ultrasonic sensor to the cargo-handling target is detected based on the measurement value obtained from each ultrasonic sensor.

According to a second aspect of the present invention, in addition to the method for detecting the height of a cargo handling object in the cargo handling machine according to the first aspect, the detection operation by the same ultrasonic sensor is performed a plurality of times at the same point and the measurement is performed. By comparing the values with each other, the correctness of the measurement value obtained from the ultrasonic sensor is determined.

According to a third aspect of the present invention, there is provided a height detecting device for a cargo handling object, comprising a cargo handling moving body that reciprocates from above to a cargo handling object. In a cargo handling machine having a mechanical structure, a plurality of ultrasonic sensors distributed and mounted on the cargo handling mechanical structure and facing the cargo handling object, and these ultrasonic sensors individually or in each specific group. Sequence control means for shifting the generation timing of the ultrasonic signal to perform the detection operation, and calculation for calculating the height of the cargo handling object of the portion facing the ultrasonic sensor based on the measurement value obtained from each ultrasonic sensor And means.

[0017]

According to the first aspect of the present invention, a plurality of ultrasonic sensors dispersively mounted on the cargo handling machine structure moving above the cargo handling object in a state of facing the cargo handling object are the cargo handling object. The distance from the ultrasonic sensor of its own to the object to be handled, therefore, by transmitting the ultrasonic signal to and receiving the ultrasonic wave reflected by the object to be returned and returned.
The height of the cargo handling object is detected. At this time, among the plurality of ultrasonic sensors, adjacent ultrasonic sensors have a large error in their measurement values due to interference of ultrasonic waves transmitted from each other. Since the detection operation is performed with the generation timing of the ultrasonic signals being shifted individually or for each specific group, the height of the cargo handling object can be detected with high accuracy without worrying about interference between the ultrasonic sensors. . Even if the detection operations by multiple ultrasonic sensors are performed at different timings in this way, the ultrasonic waves are used in a non-contact manner without the actual landing operation, so high-speed and short-time measurement processing is possible. Even if the cargo handling machine is automatically operated, safe operation of the bucket is ensured.

According to the second aspect of the present invention, the detection operation by the same ultrasonic sensor is performed a plurality of times at the same point and the correctness of the measured value is determined by comparing the measured values with each other. For measurement values that have a large error due to irregular reflection due to airborne dust, etc., the value can be discarded as an error and only the correct measurement value can be adopted, so the height of the cargo handling target can be detected with high reliability. .

According to the invention of claim 3, claim 1
In order to realize the detection method of the described invention, a plurality of ultrasonic sensors are dispersed and mounted on a cargo handling machine structure moving above the cargo handling object, and the cargo handling machine is generally equipped with this type of cargo handling machine. The sequence control means may be used to shift the detection operation timing of these ultrasonic sensors, and a cargo handling machine with high economy and reliability is provided.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. This embodiment is applied to a bucket crane that is automatically operated in a refuse incineration plant. First, a bucket crane 4 is installed above the large-capacity pit 3 that has a concrete wall 1 and into which garbage (objects of cargo handling) 2 is carried. This bucket crane 4 has an elongated crane girder (cargo handling machine structure) 5 that is driven to run in the front and back direction (travel direction) of the dust 2 in the pit 3 at the upper end of the pit 3, and this crane girder 5. A traverse trolley 6 mounted on the top and driven to traverse in the left-right direction of the paper (horizontal direction), and a bucket 8 suspended from the traverse trolley 6 by a hoisting / unwinding mechanism (not shown) and a rope 7. I have it. Here, a hopper 9 for incinerating dust is provided in the pit 3 adjacent to the bucket 8 in the transverse direction.

As a result, the bucket 8 can be displaced in the traverse direction according to the traverse trolley 6 and can be displaced in the traveling direction as the crane girder 5 travels, and can be unwound and hoisted by the rope 7. Thus, it can be reciprocally moved up and down, and can be three-dimensionally displaced above the pit 3 and the hopper 9. This allows
Basically, in the pit 3, the bucket 8 is lowered to the position of the dust 2 to grip the dust 2, and then raised and traversed, the bucket 8 is moved to the position of the hopper 9, and the bucket 8 is moved at this position. By opening the trash 2 hopper 9
It is thrown in.

In such a bucket crane system, in this embodiment, first, a plurality of ultrasonic sensors 10a to 10d shown by LS1 to LS4 are attached to the lower surface of the crane girder 5. That is, when the length of the pits 3 in the transverse direction is 15 m, the ultrasonic sensors are arranged at intervals of 3 m. Therefore, in this embodiment, four ultrasonic sensors 10a to 10d are used. That is, the ultrasonic sensors 10a and 10d at the left and right ends are installed 3 m away from the concrete wall 1 (of course, the number is not limited to four depending on the size of the pit 3 or the like). Furthermore, these ultrasonic sensors 10a-10d
Is mounted in a direction facing the dust 2 in the pit 3, but more specifically, since a considerable directivity can be expected due to the nature of the ultrasonic wave, any ultrasonic sensor 10a to 10d should be directed directly below. It is mounted to emit ultrasonic waves.

Here, these ultrasonic sensors 10a to 1 are used.
0d uses the principle that when an ultrasonic wave is transmitted, this ultrasonic wave is reflected by the object and returns, and by measuring the time after transmission / reception, the ultrasonic sensor and the object It has a well-known structure that is small, lightweight and inexpensive for calculating and measuring the distance between them. In this embodiment, the distance between the ultrasonic sensors 10a to 10d and the dust 2 (bucket 8
Is used to measure the distance from which the crane girder 5 should be unwound.

These ultrasonic sensors 10a to 10d are level controllers 11a to 1 indicated by LC1 to LC4, respectively.
It is connected to 11d. These level controllers 11a to 11d are for converting signals (measurement values) obtained from the ultrasonic sensors 10a to 10d into analog signals of 4 to 20 mA and transmitting and outputting them in a state with excellent noise resistance. In addition, these ultrasonic sensors 10a to 10
d and the level controllers 11a to 11d are sequence controllers (sequence control means) 12 shown by PLC.
It is connected to the. The sequence controller 12 itself is usually an essential component of this kind of automatically operated bucket crane system, regardless of its size or size.
13 and an I / O port 14. In this embodiment, predetermined software is incorporated in the CPU 13 in the sequence controller 12 as described above, and the ultrasonic sensors 10a to 10a for measuring the height of a dust pile as described later are used.
It is used for d sequence control. Here, the number of I / O signals required for measuring the height of the dust pile in this embodiment is small, and four digital signals are used for transmitting the ultrasonic signals of the ultrasonic sensors 10a to 10d, and each level controller 11a. Four analog signals of 11b are enough for a total of eight ports. By the way, since the I / O signals handled by this kind of automatically operated bucket crane system reach a level of 500 even in a small-scale system, it is necessary to add four ultrasonic sensors 10a to 10d. Accompanying
Even if the number of I / O signals increases by about 8, the additional cost for constructing the system will be small.

In such a structure, the ultrasonic sensor 1
A method of measuring the height of dust piles using 0a to 10d will be described.

First, four ultrasonic sensors 10a to 10d
It is assumed that the detection operations are all performed at the same timing.
Generally, due to the nature of ultrasonic sensors, an error often occurs in a measured value due to interference of ultrasonic signals transmitted by other ultrasonic sensors in the vicinity. In the distributed arrangement of the ultrasonic sensors 10a to 10d for every 3 m as described above, it is usually considered that the ultrasonic sensors 10a to 10d are arranged close to each other such that interference between the sensors occurs. As a result, when all of the ultrasonic sensors 10a to 10d are detected at the same timing, for example, the ultrasonic sensor 10b will detect the height of the dust peak of the dust 2 located directly below the ultrasonic sensor 10b. Also, the ultrasonic signal transmitted from the adjacent ultrasonic sensor 10a may be diffusely reflected to the ultrasonic sensor 10b side, and even if the height of the dust mountain directly below the ultrasonic sensor 10b is actually a low level, As a result of receiving the interference due to the diffused reflection, the height of the dust mountain directly below the ultrasonic sensor 10b may be measured as high, and thus it cannot be adopted.

On the other hand, when a plurality of ultrasonic sensors are dispersedly arranged so as not to cause mutual interference, the measurement points (addresses) are too coarse, which is not preferable. By the way, in order to completely prevent mutual interference between the ultrasonic sensors, only one ultrasonic sensor is attached to the lower surface of the crane girder 5, and the swing (pivot) mechanism allows this one ultrasonic sensor to be used. It is also possible to sequentially sense the planes of the dust 2 in the pit 3. However, it is not preferable from the viewpoint of equipment cost, etc. to have a structure with a complicated rocking mechanism under an environmental condition with a lot of dust, such as a dust incinerator.

In consideration of these points, in the present embodiment, the ultrasonic sensor 10 is used so that the measurement points are not so rough.
Even if the a to 10d are arranged in a state of being close enough to cause mutual interference between adjacent ones, the sequence controller 12 is arranged so that the mutual interference does not affect the measurement result.
These ultrasonic sensors 10a to 10a are controlled by the sequence control on the program software incorporated in the CPU 13 of
With respect to d, the detection operation is performed by shifting the generation timing of the ultrasonic signal individually. This detection operation is executed when the bucket crane 4 (crane girder 5) is stopped.

For example, in a state where the crane girder 5 is stopped at a certain position in the traveling direction, first, the sequence controller 12 gives an ultrasonic wave transmission command signal only to the ultrasonic sensor 10a via the level controller 11a. , The ultrasonic sensor 10a transmits an ultrasonic signal in a direct downward direction, the ultrasonic sensor 10a receives the ultrasonic signal reflected and returned by the dust 2, and the sequence controller 12 passes through the level controller 11a. By outputting to the side of the ultrasonic sensor 10a, the detection operation of the height of the dust mountain of the dust 2 just below the ultrasonic sensor 10a is completed. The actual height of the dust mountain is calculated by the CPU 13 which receives the signal from the level controller 11a and functions as an arithmetic unit. Since the sequence controller 12 controls the other ultrasonic sensors 10b to 10d so as not to emit ultrasonic signals during execution of the detection operation, the ultrasonic sensor 10a transmits the ultrasonic signals generated by itself. Since only the reflected component of the sensor will be received and the influence of interference between the sensors will not be received, highly accurate measurement will be performed.

When the detection operation by the ultrasonic sensor 10a is completed, the sequence controller 12 gives the transmission command signal of the ultrasonic signal only to the next ultrasonic sensor 10b to execute the detection operation in the same manner, and thereafter, The ultrasonic sensors 10c and 10d are also allowed to individually perform the detection operation at individual timings, and the ultrasonic sensors 10b and 1d
The height of the trash pile of the trash 2 just below 0c and 10d is measured.

Here, with respect to one set of ultrasonic sensor and level controller, for example, a set including the ultrasonic sensor 10a and the level controller 11a, the time required from the transmission of the ultrasonic signal to the completion of the calculation measurement is 100 to 2.
00 msec is sufficient, and four ultrasonic sensors 10a-1
Even if the detection operation by 0d is performed with a shifted timing,
The total time required to measure the height of dust piles for these ultrasonic sensors 10a to 10d is 1 second or less. Therefore, the height of the dust pile can be measured without any trouble in the cycle time of the bucket crane 4.

It should be noted that, in the present embodiment, 4 in the transverse direction.
The ultrasonic sensors 10a to 10d are arranged in a distributed manner, and it is possible to measure the height of dust piles corresponding to addresses divided into four sections in the transverse direction. In the traveling direction, the above-described detection operation is performed at each position where the crane girder 5 stops traveling. Therefore, if the crane girder 5 arbitrarily stops at 20 points in the traveling direction, the present embodiment is provided. However, it can be understood that the dust plane in the pit 3 can be divided into a total of 80 addresses and the dust mountain height can be measured.

By the way, in an environment such as a refuse incineration plant, in addition to the diffuse reflection of ultrasonic waves by the concrete wall 1 of the pit 3, due to the nature of the dust 2, the diffuse reflection of ultrasonic waves by dust floating in the air above the pit 3 However, these ultrasonic sensors 1
This may cause a measurement error due to 0a to 10d.

Particularly, in the case of the ultrasonic sensors 10a and 10d close to the concrete wall 1, it is considered that they are easily affected by the irregular reflection of ultrasonic waves by the concrete wall 1. In this respect, in the present embodiment, attention is paid to the point that the directivity of the ultrasonic waves is high, and the crane girders 5 are arranged so that the ultrasonic sensors 10a and 10d emit ultrasonic signals directly below the crane girders 5. Since it is attached to the concrete wall 1, it is possible to identify the signal regarding the irregular reflection by the concrete wall 1, so that the influence of the irregular reflection on the measurement value can be avoided.

On the other hand, when considering the influence of irregular reflection due to dust floating in the air in the pit 3, it is considered to be transient. Therefore, in this embodiment, when the bucket crane 4 (crane girder 5) is stopped, the ultrasonic sensors 10a-1a
By performing the detection operation with the timing shifted by 0d a plurality of times, it is possible to prevent the influence of highly transient diffuse reflection. That is, when the bucket crane 4 is stopped, the ultrasonic sensors 10a to 10d are caused to perform a plurality of detection operations, and the measurement is performed a plurality of times at the same point (address) of the dust 2 and is time-based. It means that the measurement is misaligned. The measurement values measured based on such a plurality of detection operations are loaded into the CPU 13 in the sequence controller 12, and the measurement values obtained from the same ultrasonic sensor are compared with each other. For example, if it is judged that the measured value of the height of the dust pile is correct, and if these measured values do not match, it is affected by the irregular reflection of dust, and the measured value of the height of the dust pile is correct. Since it does not exist, a measurement error due to the influence of irregular reflection of dust can be prevented by performing a soft process such as performing the detection operation again.
This improves the reliability of the measured value.

Here, these ultrasonic sensors 10a-1
Regarding 0d, as a method of performing the detection operation a plurality of times at the same point, for example, the ultrasonic sensor 10a → the ultrasonic sensor 10b → the ultrasonic sensor 10c → the ultrasonic sensor 10d.
The ultrasonic sensor to be continuously operated may be changed such as → ultrasonic sensor 10a →. Alternatively, it may take some time (for example, 1 sec) for the same ultrasonic sensor, such as the ultrasonic sensor 10a → (1 sec rest) → the ultrasonic sensor 10a → the ultrasonic sensor 10b → (1 sec rest) → the ultrasonic sensor 10b → ... The ultrasonic sensors to be operated may be sequentially changed while repeating the driving.

Whichever method is used, each ultrasonic sensor 10
Since the time required for each measurement by a to 10d is extremely short, even if the ultrasonic wave sensors 10a to 10d are detected a plurality of times when the bucket crane 4 is stopped, automatic operation is performed. The influence on the cycle time of the bucket crane 4 that has been removed can be ignored. This is because the bucket crane 4 that is automatically operated is
-A TO signal is given to start traverse / travel, but, for example, when the dust 8 is grabbed by the bucket 8, the bucket 8 is unwound after the TO position is reached, so the bucket crane 4 travels. This is because the stop time can be expected to be at least 30 to 50 seconds.

In this embodiment, the sequence control is performed such that all the ultrasonic sensors 10a to 10d are individually detected without timing overlap, but for example, the ultrasonic sensors 10a and 10c are ultrasonically controlled. When the ultrasonic sensors 10b and 10d do not cause mutual interference with each other under the condition that ultrasonic mutual interference does not occur, the ultrasonic sensors 10b and 10d are grouped as a specific group, and the ultrasonic sensors 10a and 10c are arranged at a certain timing. Detect the group of
The sequence controller 12 may control the group of the ultrasonic sensors 10b and 10d to perform a detection operation at the next certain timing. According to this method, the measurement operation can be performed at a higher speed without being affected by mutual interference. That is, the shape of the crane,
Depending on the size, the arrangement relationship of the ultrasonic sensors, and the like, the ultrasonic sensors that do not interfere with each other may be grouped so that they belong to the same group.

Further, although the present embodiment has been described as an application example to the bucket crane 4 which is automatically operated in the garbage incineration plant, the bucket crane is not limited to such an apparatus and the bucket is raised and lowered toward the object in the automatic crane. The same can be applied to any device in which automatic measurement of the height of the object is essential for moving it. Specifically, the present invention can be applied to automation of an overhead crane for scrap handling in a steel factory and automation of a large unloader for ore carriers.

[0040]

According to the first aspect of the present invention, a plurality of ultrasonic sensors are provided in a cargo handling machine structure that is equipped with a bucket that reciprocates from above to the cargo handling object and that moves above the cargo handling object. Are mounted while being dispersed while facing the cargo-handling target, and these ultrasonic sensors are subjected to a detection operation by shifting the generation timing of the ultrasonic signals individually or for each specific group by the sequence control means. Since the distance from the ultrasonic sensor to the cargo handling object is detected based on the measurement value obtained from the ultrasonic sensor,
The height of objects to be handled can be detected with high accuracy without worrying about interference between ultrasonic sensors, and ultrasonic waves can be used for non-contact without actually landing on the objects to be handled. Since the measurement processing can be performed at high speed and in a short time, the safe operation of the bucket can be ensured when the cargo handling machine is automatically operated.

According to the second aspect of the invention, the detection operation by the same ultrasonic sensor is performed a plurality of times at the same point, and the measurement values obtained from the ultrasonic sensor are determined by comparing the measurement values with each other. Therefore, in addition to the effect according to the invention of claim 1, for a measurement value with a large error due to the influence of diffuse reflection due to dust or the like that is highly transient in the air, the value is discarded as an error and correct measurement is performed. Only the value can be adopted, and the height of the cargo handling object can be detected with high reliability.

According to the third aspect of the invention, there is provided a cargo handling machine having a cargo handling moving body that reciprocates from above to a cargo handling object and moving above the cargo handling object. A plurality of ultrasonic sensors that are installed in a distributed manner in the cargo handling mechanical structure and face the cargo handling object, and detect the ultrasonic sensors by shifting the generation timing of the ultrasonic signals individually or in each specific group. The sequence control means for performing the operation and the calculation means for calculating the height of the object to be handled at the portion facing the ultrasonic sensor based on the measurement value obtained from each ultrasonic sensor are provided. In realizing the detection method of the described invention,
A plurality of ultrasonic sensors are dispersed and mounted on a cargo handling machine structure moving above the cargo handling object, and these ultrasonic sensors are utilized by utilizing a sequence control means generally equipped in this cargo handling machine. It suffices if the software is incorporated so as to shift the timing of the detection operation of the above, and it is possible to provide a highly economical and reliable cargo handling machine with a function capable of highly accurately detecting the height of the cargo handling target. .

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a bucket crane installation example in a garbage incineration plant showing an embodiment of the present invention.

FIG. 2 is a block diagram showing a part of the electrical system extracted.

[Explanation of symbols]

 2 Object of Cargo Handling 4 Cargo Handling Machine 5 Cargo Handling Machine Structure 8 Bucket 10a-10d Ultrasonic Sensor 12 Sequence Control Means 13 Arithmetic Means

Claims (3)

[Claims] 1. A plurality of ultrasonic sensors are dispersed while facing a cargo-handling target object in a cargo-handling mechanical structure that is provided with a bucket that reciprocates from above to the cargo-handling target object and moves above the cargo-handling target object. Then, these ultrasonic sensors are detected individually by sequence control means by shifting the generation timing of the ultrasonic signals individually or in each specific group, and based on the measurement values obtained from each ultrasonic sensor. A method for detecting the height of a cargo handling object in a cargo handling machine, wherein a distance from the ultrasonic sensor to the cargo handling target is detected. 2. The detection operation by the same ultrasonic sensor is performed a plurality of times at the same point, and the correctness of the measured value obtained from the ultrasonic sensor is determined by comparing the measured values with each other. The method for detecting the height of a cargo handling object in a cargo handling machine according to claim 1. 3. A cargo handling machine having a cargo handling machine structure which moves reciprocally from above to a cargo handling object and which moves above the cargo handling object, wherein the cargo handling machine structure is dispersed in the cargo handling machine structure. A plurality of ultrasonic sensors that are mounted and face the cargo-handling target, and a sequence control unit that performs detection operation by shifting the generation timing of the ultrasonic signals individually or for each specific group of these ultrasonic sensors; And a height of the cargo handling object in the cargo handling machine, which is provided with a computing means for computing the height of the cargo handling object at a portion facing the ultrasonic sensor based on a measurement value obtained from each ultrasonic sensor. Detection device.