JP2022041472A - Crane and crane control device - Google Patents

Abstract

To provide a crane and a crane control device capable of accurately grasping brake performance.SOLUTION: A calculation unit 52 calculates brake torque during braking of a brake 22. Thus, performance of the brake 22 can be grasped on the basis of reduction of the brake torque or the like related to the calculation result. In this case, for example, when the calculation unit 52 calculates the brake torque on the basis of information including a brake operation delay, the calculation result includes an error for real brake torque. On the other hand, the calculation unit 52 calculates the brake torque with the influence of the brake operation delay when the brake 22 operates into consideration. In this case, the calculation unit 52 can accurately calculate the brake torque.SELECTED DRAWING: Figure 2

Description

The present disclosure relates to a crane and a crane control device.

Patent Document 1 describes a crane capable of diagnosing a brake failure. In the crane of Patent Document 1, the rotation speed of the rotation shaft of the drive motor is automatically measured from the time when the brake is applied to the drive motor to the time required until the drive motor is stopped. The brake performance is judged by inputting this measured value to the arithmetic unit and comparing it with the reference value stored in the arithmetic unit.

Japanese Unexamined Patent Publication No. 58-100686

However, in the above-mentioned crane, the rotation angle (or required time) is measured and the value is compared with the threshold value to determine the operating state of the brake (fault diagnosis), but the rotation angle from the start to the stop of the operation is determined. Therefore, the transition state in the middle is not taken into consideration. Therefore, there is a problem that the performance of the brake cannot be grasped accurately.

It is an object of the present disclosure to provide a crane capable of accurately grasping the performance of a brake, and a crane control device.

The crane according to one aspect of the present disclosure includes a brake for braking the operation of the crane and a calculation unit for calculating the brake torque at the time of braking of the brake, and the calculation unit includes a brake operation delay when the brake is operated. Calculate the brake torque in consideration of the effect.

The calculation unit calculates the brake torque when the brake is braked. Therefore, it is possible to grasp the performance of the brake based on the decrease in the brake torque related to the calculation result. Here, for example, when the calculation unit calculates the brake torque based on the information including the brake operation delay, the calculation result includes an error with respect to the actual brake torque. On the other hand, the calculation unit calculates the brake torque in consideration of the influence of the brake operation delay when the brake operates. In this case, the calculation unit can calculate the brake torque with high accuracy. This makes it possible to accurately grasp the performance of the brake.

The calculation unit may calculate the brake operation delay. In this case, the calculation unit can accurately calculate the brake torque by using the brake operation delay calculated according to the situation, as compared with the case of using the brake operation delay prepared in advance, for example. Further, it is possible to grasp the performance of the brake by using the calculated brake operation delay.

The brake operation delay may include a mechanical delay from the start of the brake operation to the action of the braking force. In this case, the calculation unit can calculate the brake torque in consideration of the delay caused by the mechanical factor of the brake.

The brake operation delay may include a control delay from the transmission of the control signal to the brake to the start of the brake operation. In this case, the calculation unit can calculate the brake torque in consideration of the delay caused by the control factor of the brake.

The calculation unit may calculate the brake torque in consideration of the influence of an external factor that affects the brake torque. In this case, the calculation unit can calculate the brake torque with high accuracy in consideration of external factors.

The crane control device according to one aspect of the present disclosure is a control device for controlling a crane including a brake for braking the operation, and includes a calculation unit for calculating a brake torque at the time of braking the brake, and the calculation unit is a brake. The brake torque is calculated in consideration of the influence on the brake operation delay when the crane operates.

According to the control device of this crane, the same operation and effect as the above-mentioned crane can be obtained.

According to the present disclosure, it is possible to provide a crane capable of accurately grasping the performance of a brake, and a crane control device.

It is a figure which shows the crane which concerns on embodiment of this invention. It is a block block composition diagram which shows the block structure of the crane which concerns on embodiment of this invention. It is a graph which shows the relationship between the motor rotation speed and time just before the brake operation and when the brake is operating. It is a graph for demonstrating the method in which a calculation part calculates a brake operation delay using approximation. It is a graph for demonstrating the method in which a calculation unit calculates a brake operation delay using a threshold value. It is a flowchart which shows each example process of the control content of the control device of the crane which concerns on this embodiment.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In each figure, the same parts or corresponding parts are designated by the same reference numerals, and duplicate description will be omitted.

FIG. 1 is a diagram showing a crane 100 according to an embodiment of the present invention. In FIG. 1, a container crane is exemplified as the crane 100. The crane 100 includes legs 8 and 9 arranged on the quay 4, and a boom portion 10 that is bridged over the legs 8 and 9 and extends to the sea side. Further, the cargo handling device 2 has a suspension device 12 that can be moved along the boom portion 10. The leg portion 8 can travel on the rail 6, and the leg portion 9 can travel on the rail 7. The lower ends 8a and 9a of the legs 8 and 9 are provided with traveling devices 13 for traveling along the rails 6 and 7, respectively. The traveling device 13 is provided for the legs 8 and 9.

Next, the block configuration of the crane 100 according to the embodiment of the present invention will be described with reference to FIG. FIG. 2 is a block configuration diagram showing a block configuration of the crane 100 according to the embodiment of the present invention. As shown in FIG. 2, the crane 100 includes a state detection unit 20, a drive unit 21, a brake 22, an output unit 23, and a control device 50.

The state detection unit 20 is a device that detects various states of the crane 100 and information indicating various states of the surrounding environment of the crane 100. The state detection unit 20 includes, for example, a load sensor that detects a load acting on the crane 100 during cargo handling, a temperature sensor that detects the disk temperature of each motor, and an anemometer that detects the wind direction and speed in the surrounding environment of the crane 100. It is composed of various detection devices. The state detection unit 20 transmits information about various states as a state signal to the control device 50.

The drive unit 21 is a device that generates a driving force for executing various operations of the crane 100. The drive unit 21 includes a motor for moving the suspension device 12, a motor for winding and lowering the suspension device 12, a motor for the traveling device 13, and a motor for the undulating device for undulating the boom unit 10. And a drive device such as an inverter for driving those motors. The drive unit 21 operates based on the operation command signal transmitted from the control device 50. Further, the drive unit 21 transmits information indicating the state of the drive unit 21, such as the rotation speed of each motor, to the control device 50 as a state signal.

The brake 22 is a device that brakes various operations of the crane 100. The brake 22 is composed of a brake device that stops the rotation of each motor included in the drive unit 21. The brake 22 stops each motor by pressing a braking force applying member such as a lining against the disc of each motor. The brake 22 operates based on the operation command signal transmitted from the control device 50. Further, the brake 22 transmits information indicating the state of the drive unit 21, such as the rotation speed of each motor, to the control device 50 as a state signal.

The output unit 23 is a device that outputs various information to the operator. The output unit 23 is composed of, for example, a monitor that outputs information as an image, a speaker that outputs information by voice, a warning light that outputs information by light, and the like. The output unit 23 outputs various information based on the signal from the control device 50.

The control device 50 includes, for example, a processor, a memory, a storage, and a communication interface, and may be configured as a computer (also referred to as an on-board automatic control PC). The processor is an arithmetic unit such as a CPU (Central Processing Unit). The memory is a storage unit such as a ROM (ReadOnly Memory) or a RAM (Random Access Memory). The storage is a storage unit (storage medium) such as a flash memory, an SSD (Solid State Drive), and an HDD (Hard Disk Drive). A communication interface is a communication device that realizes data communication. The processor controls the memory, the storage, and the communication interface, and realizes the function as the control device 50 described later. In the control device 50, for example, the program stored in the ROM is loaded into the RAM, and the program loaded in the RAM is executed by the CPU to realize various functions. The number of computers constituting the control device 50 may be singular or plural.

The control device 50 includes an operation control unit 51, a calculation unit 52, a monitoring unit 53, and an output control unit 54.

The operation control unit 51 controls the operation of the crane 100. The operation control unit 51 transmits an operation command signal to the drive unit 21 in order to execute the desired operation of the crane 100. Further, when the operation of the crane 100 is stopped, the operation control unit 51 transmits an operation command signal to the brake 22. For example, when the crane 100 winds the lifting device 12, the operation control unit 51 transmits an operation command to the motor for hoisting to wind the crane 100. Then, when the hoisting of the lifting device 12 is stopped, the operation control unit 51 transmits an operation command signal to the brake 22 corresponding to the hoisting motor so as to stop the rotation of the hoisting motor.

The calculation unit 52 calculates the brake torque when the brake 22 is braking. The calculation unit 52 calculates the brake torque by monitoring the change in the motor rotation speed of the motor of the drive unit 21 at an arbitrary timing during braking by the brake 22. Further, in the present embodiment, the calculation unit 52 calculates the brake torque in consideration of the influence of the brake operation delay when the brake 22 operates. The brake operation delay includes a mechanical delay from the start of the operation of the brake 22 to the action of the braking force. Further, the brake operation delay includes a control delay from the transmission of the control signal to the brake 22 to the start of the operation of the brake 22.

Here, with reference to FIG. 3, an example of a method of calculating the brake torque by the calculation unit 52 and an example of the brake operation delay will be described. FIG. 3 is a graph showing the relationship between the motor rotation speed and time immediately before the brake 22 operates and when the brake 22 operates. The lower graph of FIG. 3 is a graph showing the timing at which the brake 22 receives the operation command signal from the control device 50. In the graph, it is assumed that the control device 50 transmits an operation command signal to the brake 22 to perform the brake at the timing of changing from "Open" to "Close". As shown in FIG. 3, when the motor is stopped, the operation control unit 51 decelerates what is rotating at a constant speed (for example, rated, that is, 100% output) to a predetermined motor rotation speed, and rotates the motor. An operation command signal is transmitted to the brake 22 at the timing of decelerating to a certain number.

In the following description, "N" indicates the motor rotation speed (rpm) of the motor to be stopped. “TS” indicates the calculation processing start time (s) for the calculation unit 52 to calculate the brake torque. “TE” indicates the calculation processing completion time (s) for the calculation unit 52 to calculate the brake torque. “NS” indicates the motor rotation speed (rpm) at the start of arithmetic processing. “NE” indicates the motor rotation speed (rpm) when the arithmetic processing is completed. In this case, the calculation unit 52 can calculate the brake torque BT of the brake 22 by the following equation (1). In addition, "GD2" shows the moment of inertia.

BT = GD2 x (| NS-NE |) / (375 x (| TS-TE |)) ... (1)

Here, as shown in FIG. 3, the slope of the graph remains “DC1” for the time “Δt1” after the operation control unit 51 transmits the operation command signal to the brake 22. This corresponds to a control delay between the time when the operation control unit 51 transmits an operation command signal and the time when the brake 22 receives the signal and starts the operation. Therefore, it can be said that "Δt1" indicates the control delay time (s). Further, the slope of the graph in the state where the brake 22 completely generates the braking force is indicated by "DC3". On the other hand, from "DC1" to "DC3", the slope of the graph becomes "DC2" larger than "DC1" and smaller than "DC3" during the time "Δt2". This corresponds to a mechanical delay between when the brake 22 comes into contact with the disc of the motor and when the braking force is fully exerted. Therefore, it can be said that "Δt ₂ " indicates the machine delay time (s). The calculation unit 52 calculates the brake torque in consideration of the brake operation delay when the brake 22 operates, that is, the control delay time Δt ₁ and the mechanical delay time Δt ₂ . Specifically, the calculation unit 52 sets the timing at which the machine delay time Δt ₂ has elapsed in the calculation processing start time TS. As a result, the slope of the graph from the calculation processing start time TS to the calculation completion time TE is constant at "DC3" in the entire area. Therefore, the calculation unit 52 removes the brake operation delay component such that the slope of the graph becomes "DC1" or "DC2" from the range between the calculation processing start time TS and the calculation completion time TE, and the brake torque. Can be calculated.

The calculation unit 52 may calculate the brake torque in consideration of the influence of an external factor that affects the brake torque. For example, the moment of inertia GD2 fluctuates depending on the load condition. Therefore, the calculation unit 52 may calculate the brake torque after correcting the moment of inertia GD2 in consideration of the fluctuation due to the load condition. Further, the calculation unit 52 may calculate the brake torque by temperature-correcting in consideration of the fluctuation of the friction coefficient due to the disk temperature.

The calculation unit 52 may acquire the brake operation delay by calculation. An example of the calculation method when the calculation unit 52 calculates the brake operation delay will be described with reference to FIGS. 4 and 5. FIG. 4 is a graph for explaining a method in which the calculation unit 52 calculates the brake operation delay using the approximation. FIG. 5 is a graph for explaining a method in which the calculation unit 52 calculates the brake operation delay using the threshold value.

The calculation of the deceleration α during brake braking will be described with reference to FIG. For example, when the calculation unit 52 calculates the deceleration α during braking at an arbitrary time t _n , the inclination of the graph in a minute time range (t _n−X to t _{n + Y} ) before and after the time t _n , That is, the deceleration α during braking is calculated. Note that nX and nY are positive integers, respectively. In FIG. 4, “α _f ” indicates the deceleration during braking when the braking force of the brake 22 is fully applied. The calculation unit 52 may calculate the deceleration α _f during braking by linear approximation using the least squares method or the like. “Α _m ” indicates the deceleration during braking when the braking force of the brake 22 rises. After transmitting the operation command signal to the brake 22, the calculation unit 52 grasps the transition of the deceleration α during brake braking while advancing the time _tun . That is, the calculation unit 52 estimates that the time from the transmission of the operation command signal to the brake 22 until the deceleration during brake braking becomes “α _m ” is the control delay time Δt ₁ . Further, the calculation unit 52 estimates that the time from when the deceleration during braking braking becomes “α _m ” to when it becomes “α _f ” is the machine delay time Δt ₂ .

Further, as shown in FIG. 5, the calculation unit 52 may calculate the deceleration α _n during braking using the formula shown in the following formula (2). For example, when the calculation unit 52 calculates the deceleration α during brake braking at an arbitrary time t _n , the deceleration during brake braking using the equation (2) using the motor rotation speed N _n at the time t _n . Calculate the velocity α _n . For example, in FIG. 5, “α _f ” indicates the deceleration during braking when the braking force of the brake 22 is fully applied. “Α _m ” indicates an example of deceleration during brake braking when the braking force of the brake 22 rises. After transmitting the operation command signal to the brake 22, the calculation unit 52 grasps the transition of the deceleration α _n during brake braking while advancing the time t _n . That is, when the control delay time Δt ₁ ends, the slope of the graph of the motor rotation speed changes, so that the value of the deceleration α _n during brake braking fluctuates abruptly. That is, if a predetermined threshold value is set for the deceleration α _n during brake braking corresponding to the control delay time Δt ₁ , the calculation unit 52 will perform the timing when the deceleration α _n during brake braking exceeds the threshold value. , It can be grasped that the control delay time Δt ₁ has ended. As a result, the calculation unit 52 can estimate the control delay time Δt ₁ . Further, when the machine delay time Δt ₂ ends, the slope of the graph of the motor rotation speed changes, so that the value of the deceleration α _n during brake braking fluctuates abruptly. That is, if a predetermined threshold value is set for the deceleration α _n during brake braking corresponding to the machine delay time Δt ₂ , the calculation unit 52 will perform the timing when the deceleration α _n during brake braking exceeds the threshold value. , It can be grasped that the machine delay time Δt ₂ has ended. As a result, the calculation unit 52 can estimate the machine delay time Δt ₂ .

α _n = (NE-N _n ) / (TE-t _n )… (2)

The monitoring unit 53 monitors the state of the brake 22 based on the calculation result of the calculation unit 52. Specifically, the monitoring unit 53 monitors the state of the brake 22 by monitoring the brake torque calculated by the calculation unit 52. For example, when the brake torque related to the calculation result of the calculation unit 52 is lower than the specified value, the monitoring unit 53 can determine that the performance of the brake 22 is deteriorated due to a device failure, maintenance failure, adjustment failure, or the like. Further, the monitoring unit 53 may monitor the control delay time Δt ₁ and the machine delay time Δt ₂ calculated by the calculation unit 52. For example, when at least one of the control delay time Δt ₁ and the machine delay time Δt ₂ becomes longer than the specified value, the monitoring unit 53 can determine that the performance of the brake 22 has deteriorated.

The monitoring unit 53 may make a determination based on the results of a plurality of calculations. For example, the monitoring unit 53 may calculate an average value of the results of a plurality of calculations and use the average value to determine the performance deterioration of the brake 22. At this time, if the calculation result is clearly an excessive value, it may be regarded as a temporary error due to an external factor, and the monitoring unit 53 may exclude it from the calculation of the average value. Further, the monitoring unit 53 may make a determination based on a single calculation result. For example, if oil or the like adheres to the brake 22, the value will fluctuate greatly from the previous calculation result. Therefore, the monitoring unit 53 may determine that the performance of the brake 22 has deteriorated if the calculation result deviates significantly from the reference even once.

The output control unit 54 generates information to be output by the output unit 23, and outputs the information to the output unit 23. The output control unit 54 issues a warning to the operator when the monitoring unit 53 determines that the performance of the brake 22 has deteriorated. Alternatively, the output control unit 54 may only alert the operator based on the monitoring result of the monitoring unit 53, and the operator may determine the actual performance deterioration of the brake 22.

Further, the output control unit 54 may output the mode of performance deterioration of the brake 22 when the mode of performance deterioration is known. For example, when "the time of the brake operation delay is normal, but the brake torque is reduced", the monitoring unit 53 can determine that the lining or the disc is deteriorated or soiled. Further, when "the time of the brake operation delay is extended, but the brake torque is normal", the monitoring unit 53 can determine that the brake mechanism or the control device (relay or the like) is malfunctioning. The output control unit 54 may output the details of these defects.

The monitoring of the performance deterioration of the brake 22 by the control device 50 as described above may be performed for each operation of the crane 100. In this case, the control device 50 can constantly monitor the brake 22. In addition, an operation for measuring the brake torque may be performed at a timing such as a periodic inspection or a crane installation. In this case, the operation mode (measurement mode) may be set so that the calculation unit 52 can easily perform the calculation. For example, the operation control unit 51 may operate the brake 22 at an earlier timing than during normal operation. For example, the operation control unit 51 operates the brake 22 after decelerating to a very low speed during normal operation, whereas the operation control unit 51 operates the brake 22 at an early timing (for example, a timing decelerated to 30% of the rating) in the measurement mode. You can do it.

Next, an example of the control content by the control device 50 of the crane 100 according to the present embodiment will be described. FIG. 6 is a flowchart showing each exemplary process of the control content of the control device 50 of the crane 100 according to the present embodiment. The process shown in FIG. 6 is executed during the cargo handling operation of the crane 100 and the operation in the measurement mode in the periodic inspection.

First, the calculation unit 52 acquires information indicating various states from the state detection unit 20, the drive unit 21, and the brake 22 (step S1). Next, the calculation unit 52 calculates the brake torque of the brake 22 and the brake operation delay (step S2). Next, the monitoring unit 53 determines whether or not the performance of the brake 22 has deteriorated based on the calculation result in step S2 (step S3).

When the monitoring unit 53 determines that the performance of the brake 22 has not deteriorated (YES in step S3), the calculation result is stored in a storage unit or the like. Then, the monitoring unit 53 may consider the calculation result stored in the storage unit at the next determination. On the other hand, when the monitoring unit 53 determines that the performance of the brake 22 has deteriorated (NO in step S3), the output control unit 54 controls the output unit 23 to give a warning (step S5) and outputs the calculation result. Store it in a storage unit.

Next, the operation / effect of the crane 100 and the control device 50 of the crane 100 according to the present embodiment will be described.

The calculation unit 52 calculates the brake torque when the brake 22 is braking. Therefore, it is possible to grasp the performance of the brake 22 based on the decrease in the brake torque related to the calculation result. Here, for example, when the calculation unit 52 calculates the brake torque based on the information including the brake operation delay, the calculation result includes an error with respect to the actual brake torque. On the other hand, the calculation unit 52 calculates the brake torque in consideration of the influence of the brake operation delay when the brake 22 operates. In this case, the calculation unit 52 can accurately calculate the brake torque. As a result, the performance of the brake 22 can be accurately grasped.

The calculation unit 52 may calculate the brake operation delay. In this case, the calculation unit 52 can accurately calculate the brake torque by using the brake operation delay calculated according to the situation, as compared with the case of using the brake operation delay prepared in advance, for example. Further, it is possible to grasp the performance of the brake by using the calculated brake operation delay.

The brake operation delay may include a mechanical delay (mechanical delay time Δt ₂ ) from the start of the operation of the brake 22 to the action of the braking force. In this case, the calculation unit 52 can calculate the brake torque in consideration of the delay caused by the mechanical factor of the brake 22.

The brake operation delay may include a control delay (control delay time Δt ₁ ) from the transmission of the control signal to the brake 22 to the start of the operation of the brake 22. In this case, the calculation unit 52 can calculate the brake torque in consideration of the delay caused by the control factor of the brake 22.

The calculation unit 52 may calculate the brake torque in consideration of the influence of an external factor that affects the brake torque. In this case, the calculation unit 52 can accurately calculate the brake torque in consideration of external factors.

The control device 50 of the crane 100 according to the present embodiment is a control device 50 for controlling the crane 100 including the brake 22 for braking the operation, and includes a calculation unit 52 for calculating the brake torque when the brake 22 is braked. The calculation unit 52 calculates the brake torque in consideration of the influence of the brake operation delay when the brake is operated.

According to the crane control device 50, the same operation and effect as the above-mentioned crane 100 can be obtained.

The present invention is not limited to the above-described embodiment.

For example, the calculation unit 52 does not have to calculate the brake operation delay, and may acquire it by reading it from a storage unit or the like.

Further, the calculation method of the brake operation delay shown in FIGS. 4 and 5 is only an example, and the calculation unit 52 may appropriately change the calculation method of the brake operation delay. Further, the method of calculating the brake torque shown in FIG. 3 and the above-mentioned equation (1) is only an example, and the calculation unit 52 may appropriately change the method of calculating the brake torque.

The type of the crane 100 is not limited to the container crane as shown in FIG. 1, and a type of crane such as an overhead crane or a bridge crane may be adopted.

22 ... Brake, 50 ... Control device, 52 ... Calculation unit, 100 ... Crane.

Claims (6)

A brake that brakes the movement of the crane and
A calculation unit that calculates the brake torque when the brake is braked is provided.
The calculation unit calculates the brake torque in consideration of the influence of the brake operation delay when the brake operates. The crane according to claim 1, wherein the calculation unit calculates the brake operation delay. The crane according to claim 1 or 2, wherein the brake operation delay includes a mechanical delay from the start of the brake operation to the action of the braking force. The crane according to any one of claims 1 to 3, wherein the brake operation delay includes a control delay from the transmission of a control signal to the brake to the start of the operation of the brake. The crane according to any one of claims 1 to 4, wherein the calculation unit calculates the brake torque in consideration of the influence of an external factor that affects the brake torque. A crane control device that controls a crane equipped with a brake that brakes its movement.
It is equipped with a calculation unit that calculates the brake torque when the brake is braked.
The calculation unit is a crane control device that calculates the brake torque in consideration of the influence of the brake operation delay when the brake operates.

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