JP2013023294A - Travel control device for cargo handling crane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a container crane from being pushed away by a wind load in the travel direction when a cargo handling crane starts traveling.SOLUTION: This travel control device includes a travel motor to supply drive power in the travel direction of the cargo handling crane and controls the torque of the travel motor in response to the wind speed in the travel direction to make the cargo handling crane into the zero speed status when the cargo handling crane stops travelling. Container crane coefficient is calculated from the relational expression established among the wind speed in the travel direction, the torque of the travel motor, and the coefficient of the container crane as the wind speed in the travel direction and the torque of the travel motor in the zero speed status being input parameters. Start torque is calculated from the above relational expression as the wind speed in the travel direction and the coefficient of the container crane immediately before the travel of the cargo handling crane starts being input parameters. In the status of the brake closed, the establishment of the start torque is confirmed and the brake is left open.

Description

  The present invention relates to a traveling control device for a cargo handling crane such as a container crane used in a container terminal of a harbor.

  A container crane that travels on a traveling rail along a quay in a container terminal of a harbor or the like is known. A container crane is used to perform a cargo handling operation of a container or the like between a ship such as a container ship that touches the quay and the land. The container crane is roughly divided into four operations. The four operations are (1) hoisting operation for moving the spreader up and down, (2) traversing operation for moving the cab and trolley to the land side and the sea side, and (3) when the container ship passes Because the boom will come into contact with the ship, the hoisting action to raise or lower the boom to avoid collisions. This is a traveling operation for moving along the container row of the container ship by the legs.

  A motor is used for the driving force of each operation, and a shoe-type brake is used for stopping. The shoe type brake is a fail-safe mechanism that always closes the brake so that the motor will not rotate unless there is an electrical signal that is a brake release command from the control device for each operation. A brake release command is output, the brake is released, the motor can rotate, and the operation of each operation is realized by the driving force of the motor.

  Regarding the traveling operation of the container crane, Patent Document 1 (Japanese Patent Publication No. 59-12598) discloses that the load applied to the left wheel and the right wheel of the crane body differs depending on the wind load in the traverse position and traverse direction of the trolley. The motor control which changes the driving torque of each of the left wheel and the right wheel is disclosed.

Japanese Patent Publication No.59-12598

  Generally, when the above-described container crane starts a traveling operation from a stopped state, after a brake release command is issued, an operation command is issued and a current is supplied to the traveling motor. If there is no wind, there is no problem with this operation procedure, but the container crane is installed at a location facing the sea and is therefore easily affected by the wind. There are places where the wind is always blowing, especially in some areas. Therefore, if there is wind, the container crane will be swept away by the wind load in the traveling direction after the brake release command and after the current is passed through the traveling motor until the torque of the traveling motor is established. There was a problem.

  As a result, the inching operation (the operation method for finely adjusting the position of the container crane in accordance with the container row of the container ship) will cause the wind to flow even though you want to move a little. In some cases, work efficiency may be reduced.

  The present invention has been made to solve the above-described problems, and is capable of preventing a container crane from being swept away by a wind load in a traveling direction when the container crane starts traveling from a stopped state. An object of the present invention is to provide a traveling control device for a crane.

  In order to achieve the above object, the present invention provides a traveling position control device for a cargo handling crane that travels on a traveling rail, a traveling motor that supplies driving force in the traveling direction of the cargo handling crane, and rotation of the traveling motor. A brake for braking the vehicle, wind speed acquisition means for acquiring the wind speed in the traveling direction, and when the crane for traveling is stopped, the torque of the traveling motor is controlled in accordance with the wind speed in the traveling direction so that the crane for handling is brought to a zero speed state. Using the zero speed control means, the wind speed in the traveling direction in the zero speed state and the torque of the traveling motor as input parameters, the relation between the wind speed in the traveling direction, the torque of the traveling motor, and the container crane coefficient Coefficient calculating means for calculating the wind speed in the traveling direction immediately before the start of traveling and the container crane As an input parameter, starting torque calculating means for calculating the torque of the traveling motor (hereinafter referred to as starting torque) from the above relational expression, and starting torque generating means for generating the starting torque in the traveling motor when the brake is closed. And starting torque establishment determining means for determining whether or not the starting torque has been established, and travel starting means for releasing the brake when the starting torque is established.

  According to this invention, at the start of traveling from the stopped state of the container crane, the starting torque according to the wind speed in the traveling direction is established and then the brake is released, so that the container crane is pushed away by the wind load in the traveling direction. Can be prevented.

It is a side view for demonstrating the structure of the crane for cargo handling formed in the container terminal etc. of a harbor. It is a front view for demonstrating the structure of the crane for cargo handling formed in the container terminal of a harbor, etc. It is a block diagram of the control apparatus which controls the traveling operation of a container crane. It is a flowchart showing the procedure of the driving | running | working stop in Embodiment 1 of this invention. Is a vector exploded view of the wind velocity V _g and trolley direction of wind velocity V _t in the running direction. It is a figure which shows the relationship between the wind speed Vg of the traveling direction regarding the container crane coefficient (alpha _), and the traveling motor torque T. FIG. It is a distribution graph of container crane coefficient (alpha). It is a flowchart showing the procedure of the driving | running | working start in Embodiment 1 of this invention. It is a timing chart which shows the example of the traveling control of this invention in case there exists a head wind. 3 is a flowchart for calculating a container crane coefficient α. In conventional travel control, it is a timing chart which shows an example when there is a headwind.

  A mode for carrying out the present invention will be described with reference to the accompanying drawings. In addition, in each figure, the same code | symbol is attached | subjected to the part which is the same or it corresponds, The duplication description is simplified or abbreviate | omitted suitably.

Embodiment 1 FIG.
[Basic configuration of crane for cargo handling]
A basic configuration of the crane for cargo handling in Embodiment 1 of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a side view for explaining a configuration of a cargo handling crane formed in a container terminal of a harbor. FIG. 2 is a front view of the cargo handling crane shown in FIG. 1.

  In FIG. 1, a quay 1 is the boundary between the sea and the land. An apron 2 which is a cargo handling area is provided on the land side of the quay 1. In the apron 2, a traveling rail 3 is laid along the quay 1 (FIG. 2). The traveling rail 3 is laid substantially parallel to the hull of the ship that comes in contact with the quay 1 and anchors. On the traveling rail 3, a cargo handling crane (hereinafter simply referred to as a container crane) 4 that loads cargo such as containers loaded on the hull between the hull and the land is disposed.

  The configuration of the container crane 4 will be described. The container crane leg portion 5 includes wheels for traveling on the traveling rail 3 on each of the four legs. Each leg is provided with a pair of an electric traveling motor 6 for driving the wheels and a shoe brake (not shown).

  At the upper part of the container crane 4 is provided a boom 7 that is horizontally provided at a predetermined height so as to be orthogonal to the traveling rail 3 in a plan view, and has one end protruding above the hull. The boom 7 is provided with a trolley 8 (having an operator cab 9) that travels along the boom 7. The trolley 8 is provided with a hoisting rope 10 such as a wire rope. On the hoisting rope 10, a spreader 11 that holds and supports a load such as a container is suspended. The spreader 11 is moved up and down (winding and lowering) by a hoisting device (not shown) around which the hoisting rope 10 is wound, and is inclined in the longitudinal direction, the lateral direction, and the horizontal within a predetermined angle. The rotation of the direction is configured to be controllable.

  Further, the container crane 4 is provided with a machine room 12 for controlling various devices such as the traveling motor 6, the trolley 8, and the hoisting device, and operates various devices according to instructions from the cab 9. Further, an anemometer 21 for measuring the wind speed of the wind blown on the container crane 4 and an anemometer 22 for measuring the wind direction are attached to the upper part of the container crane 4.

  In such a configuration, the container crane 4 roughly performs four operations. The four operations are a hoisting operation for moving the spreader 11 in the vertical direction, a traversing operation for moving the cab 9 and the trolley 8 along the boom 7 to the land side and the sea side (the traversing direction), It is the raising / lowering operation | movement which falls, and the traveling operation | movement which moves the container crane 4 on the traveling rail 3 in a traveling direction.

  FIG. 3 is a block diagram of a control device that controls the traveling operation of the container crane 4 according to the first embodiment of the present invention. In FIG. 3, each part of this control apparatus is represented by blocks, and transmission of main signals between the blocks is represented by arrows. A travel control device 24 is provided in the control device of the container crane 4 shown in FIG. The travel control device 24 is a control device having a PLC (Programmable Logic Controller), and is provided in the cab 9 or the machine room 12. The travel control device 24 is connected to the anemometer 21 and the anemometer 22 described above, and information on the wind speed and the wind direction is input as needed. In addition, the travel control device 24 is connected to a travel speed command device 23, a storage device 25, a travel motor control device 26, and a shoe-type brake for braking the travel motor (not shown; hereinafter also simply referred to as a brake). Yes. The travel speed command device 23 is a controller that is provided in the cab 9 and that is operated by the driver such as a drive command (speed command) and a stop command. The travel control device 24 generates a speed reference according to a command from the travel speed command device 23 and outputs it to the travel motor control device 26. The storage device 25 is a readable / writable memory based on a command from the traveling control device 24. The travel motor control device 26 is a drive device that receives a speed reference as an input and supplies a current according to the speed reference to the travel motor 6. The travel motor control device 26 outputs the torque value of the travel motor 6 to the travel control device 24. The shoe-type brake for braking the traveling motor is a mechanism that always closes the brake so that the motor does not rotate unless there is an electrical signal that is a brake release command from the traveling control device 24.

  In the configuration described above, generally, when the container crane 4 starts a traveling operation from a stopped state, first, a brake release command is issued from the traveling control device 24 to the brake. Thereafter, a current is passed through the traveling motor 6 in accordance with a speed reference corresponding to the operation command. When the container crane 4 stops from the traveling state, the brake is forcibly closed and stopped when the traveling motor 6 decelerates to a predetermined speed (for example, about 15% of the rated speed).

  However, since the container crane 4 is installed at a position facing the sea, it is easily affected by wind. In some areas, there are always winds. Therefore, when there is wind, there is a problem that the container crane 4 is swept away in an unexpected direction by the wind load in the traveling direction from when the brake release command is issued until the torque of the traveling motor 6 is established. It was. As a result, there has been a case where the work efficiency is greatly lowered during the inching operation.

  In addition, when stopping from the running state, the brake was tightened when the running speed was reduced to a few percent of the rated speed, so the brake was tightened while the motor was rotating, and the load on the brake pad was heavy. .

  FIG. 11 is a diagram illustrating an example of the above-described conventional traveling control, and is a timing chart illustrating an example when there is a headwind. When a driving command is issued at time t1, the traveling control device 24 generates a speed reference for starting a traveling operation simultaneously with issuing a brake release command to the brake. After the time t1, the container crane 4 does not have sufficient driving force until the torque of the traveling motor 6 is established according to the speed reference. Therefore, it receives a headwind and flows in the opposite direction (FIG. 11B). Further, when a stop command is issued at time t3, a speed reference for stopping is generated, and the torque of the traveling motor 6 is reduced according to the speed reference. At time t4, the brake is closed when the traveling speed is reduced to several percent of the rated speed even though the traveling motor 6 is in operation (FIG. 11B). Therefore, a great burden is applied to the brake pad.

[Characteristic Control of Embodiment 1]
Next, characteristic traveling control of the present embodiment that solves the above-described problem will be described. One of the features of this traveling control is that when the container crane 4 stops traveling, the torque of the traveling motor 6 is controlled according to the wind speed in the traveling direction, so that the container crane 4 is in a zero speed state (a state where the crane is completely stopped). The zero speed control is performed and the brake is tightened in the complete stop state. Thereby, the burden on a brake pad can be reduced. Further, a major feature of this travel control is that the above-mentioned zero speed state is used to store the relationship between the travel motor torque necessary for the container crane 4 not to be blown by the wind and the wind speed in the travel direction. At the start of traveling of the container crane 4, the necessary traveling motor torque corresponding to the wind speed in the traveling direction is established and then the brake is released. Thereby, it is possible to prevent the container crane 4 from being swept away by the influence of the wind at the start of traveling.

(Characteristic control when driving is stopped)
More specific travel control of this embodiment will be described. FIG. 4 is a flowchart showing the procedure of stopping traveling according to the present invention. When the container crane 4 stops while traveling, first, a stop command is output from the travel speed command device 23 to the travel control device 24 (step S30). The traveling control device 24 receives the stop command and generates a speed reference toward the crane stop. This speed reference is speed control information for decelerating from the current speed to zero speed. The travel control device 24 outputs a speed reference to the travel motor control device 26. The traveling motor control device 26 decelerates and stops the traveling motor 6 based on the speed reference. Thereafter, torque control for maintaining the container crane 4 in a stopped state is started (step S31). The control state in a state where the container crane 4 is completely stopped is referred to as zero speed control. The travel control device 24 calculates the wind speed in the travel direction based on the wind speed and the wind direction input from the anemometer 21 and the anemometer 22 during the zero speed control (step S32). As shown in FIG. 5, the wind speed in the traveling direction can be calculated from V _g = V cos θ _g by vector decomposition of the wind speed V into the wind speed V _{g in the} traveling direction and the wind speed V _{t in the} trolley direction (transverse direction). During zero speed control, it is generating driving motor torque so as not to move the container crane 4 under the influence of wind load of wind speed V _g. This travel motor torque is detected by the travel motor control device 26. The traveling control device 24 reads the traveling motor torque at the time of zero speed control from the traveling motor control device 26 (step S33). Travel control device 24 calculates a container crane coefficient α based on the travel motor torque and wind velocity V _g of the traveling direction (Step S34). Then, traveling control unit 24 writes the relationship between the traveling motor torque wind speed V _g of the traveling direction, and the calculated container crane coefficient α in the storage device 25 (step S35). The storage device 25 stores these histories. The traveling control device 24 calculates the average of the container crane coefficient α from the history stored in the storage device 25, and holds it in the traveling control device 24 (step S36). Thereafter, the traveling control device 24 turns off the brake release command and closes the brake (step S37).

(Calculation of container crane coefficient α)
The method for calculating the container crane coefficient α will be described in detail. Figure 6 is a diagram showing a relationship between wind velocity V _g and the travel motor torque T in the running direction about the container crane coefficient alpha. The value of the wind velocity V _g of the traveling direction on the horizontal axis, when the value of the travel motor torque T on the vertical axis, as shown in FIG. 6, the traveling motor torque T is a graph in proportion to the square of the wind speed V _g. The container crane coefficient α can be calculated based on the equation (1) using the wind speed _Vg and the traveling motor torque T as input parameters.

The relationship between the wind load and the wind speed is not general because there are a derivation method in the building field, a derivation method in the crane machine, and various derivation methods, but as an example, an explanation will be given using an expression relating to the wind load of the crane machine. Expression (2) is an expression indicating the speed pressure q that is a component of the wind load W. Speed pressure q includes the square of the wind speed V _g as a coefficient, the height h of anemometers 21 are installed [m], the formula (2) using the gravity factor g.

The wind load W is expressed by Equation (3) using the speed pressure q, the wind force coefficient C, and the pressure receiving area A [m ² ] of the container crane 4. Further, the formula (2) of the speed pressure q, wherein the wind load W from the equation (3) of the wind load W, as shown in Equation (4) is divided into a square and other factors of the wind speed V _g . The other coefficients are values obtained by conducting an actual machine test and the like because they are a collection of inherent coefficients related to each container crane.

An expression obtained by multiplying the wind load W by a torque conversion coefficient k [m] is Expression (5). When a coefficient other than the actually detected wind speed V _g is set as the container crane coefficient α, Expression (1) equivalent to Expression (5) is obtained.

As shown in the equation (1) and FIG. 6, if there is data on the wind speed _Vg and the traveling motor torque even at one point, the container crane coefficient α can be obtained. If the data of the wind speed _Vg and the traveling motor torque are increased, the data of the container crane coefficient α is distributed as shown in FIG. By obtaining this average value, an accurate value is obtained as a coefficient related to the container crane. The storage device 25 sequentially calculates the container crane coefficient α from the information on the wind speed _Vg and the traveling motor torque. Therefore, with respect to not measured wind speed V _g, a traveling motor torque required can be derived from the equation (1). Further, since the container crane coefficient α is a coefficient that differs between the tailwind and the headwind, it is calculated separately.

(Characteristic control at the start of driving)
Next, the control at the start of traveling according to this embodiment will be described. FIG. 8 is a flowchart showing a procedure for starting traveling according to the present invention. First, an operation command (speed command) is issued from the travel speed command device 23 to start traveling (step S40). Travel control device 24 calculates a wind velocity V _g of the traveling direction from the detection value of the anemometer 21 at the moment the operation command is issued wind direction meter 22 (step S41). Travel control device 24, the wind speed V _g and container cranes coefficient calculated traveling direction α as an input parameter from equation (1), the travel motor torque for not swept away by the wind (hereinafter, also referred to as a starting torque.) The Calculate (step S42). The traveling control device 24 outputs this starting torque to the traveling motor control device 26 (step S43). Then, it is sequentially determined whether or not the torque value of the travel motor 6 has become the same value as the starting torque (whether or not the torque is established) (step S44). After the establishment of torque is confirmed, a brake release command is output (step S45). After that, the vehicle travels according to the speed reference generation value.

(Example of travel control)
FIG. 9 is a timing chart showing an example of travel control according to the present invention when there is a headwind as in FIG. 11 described above. At time t0, a traveling motor torque (starting torque) corresponding to the operation command is calculated (steps S40 to S42 in FIG. 8). After the time t0, the traveling motor control device 26 passes a current corresponding to the input starting torque to the traveling motor 6 (step S43 in FIG. 8). When it is confirmed that the torque of the travel motor 6 is established at time t1, a brake release command is output (steps S44 to S45 in FIG. 8). Since the torque is established, the speed feedback can be made to follow the speed reference from time t1 without being blown by the wind.

  At time t3, when a stop command is input from the travel speed command device 23, zero speed control is performed after deceleration stop according to the speed reference, and the brake is closed in the complete stop state (FIG. 4). Since the brake is closed while the traveling motor 6 is not rotating, wear of the brake pad can be suppressed.

As explained above, according to the present invention,
(1) When the container crane 4 starts traveling from the stopped state, the traveling motor torque necessary to prevent the container crane 4 from being blown away is established, and then the brake is released. Therefore, it is possible to prevent the container crane from flowing in the traveling direction.
(2) When the container crane 4 stops traveling, the brake is closed in a complete stop state under zero speed control. Therefore, the burden on the brake pad can be reduced.

  In the first embodiment described above, the history of the container crane coefficient α is sequentially stored in the storage device 25 and the average value is used as the container crane coefficient α. However, the present invention is not limited to this. For example, the container crane coefficient α may be first calculated at the time of testing or before cargo handling, and the container crane coefficient α may be used as a fixed value. FIG. 10 is a flowchart for calculating the container crane coefficient α. The processing in FIG. 10 is the same as the contents described in steps S30 to S34 in FIG. After several tests, the average value of the container crane coefficient α is taken and set in the travel control device 24. At the start of traveling, the above-described processing of FIG. 8 is performed using the fixed container crane coefficient α. By using the fixed container crane coefficient α, the calculation process can be simplified as compared with the method of sequentially updating the container crane coefficient α. Further, by periodically performing the procedure of FIG. 10, even if the container crane coefficient α changes due to aging deterioration, it can be readjusted.

  Further, the container crane coefficient α varies in surface area depending on whether the container crane 4 is holding the container or not. In addition, when the power feeding is a traveling cable reel type, the area that receives the wind of the cable in the cable reel varies depending on the traveling position. Furthermore, characteristics such as the friction coefficient of the machine change due to aging and seasonal temperature changes. Therefore, in order to obtain a higher effect, the container crane coefficient may be corrected each time based on such information.

1 quay, 2 apron, 3 traveling rail,
4 container cranes, 5 container crane legs, 6 travel motors,
7 boom, 8 trolley, 9 cab,
10 hoisting rope, 11 spreader, 12 machine room,
21 Anemometer, 22 Anemometer, 23 Travel speed command device,
24 travel control device, 25 storage device, 26 travel motor control device,
V _g the running direction of the wind speed, T traveling motor torque, α container crane coefficient

Claims (3)

In a traveling position control device for a cargo handling crane that travels on a traveling rail,
A traveling motor for supplying a driving force in the traveling direction of the crane for cargo handling;
A brake for braking the rotation of the travel motor;
Wind speed acquisition means for acquiring the wind speed in the traveling direction;
Zero speed control means for controlling the torque of the traveling motor in accordance with the wind speed in the traveling direction when the traveling crane is stopped, and setting the cargo handling crane to a zero speed state;
A coefficient for calculating the container crane coefficient from the relational expression established between the wind speed in the traveling direction, the torque of the traveling motor, and the container crane coefficient using the wind speed in the traveling direction and the torque of the traveling motor in the zero speed state as input parameters. A calculation means;
Immediately before starting the traveling of the cargo handling crane, the torque of the traveling motor (hereinafter referred to as starting torque) is calculated from the relational expression using the wind speed in the traveling direction immediately before the traveling and the container crane coefficient as input parameters. Starting torque calculating means;
Starting torque generating means for generating the starting torque in the travel motor in a state where the brake is closed;
Starting torque establishment determination means for determining whether the starting torque has been established;
A travel start means for releasing the brake when the starting torque is established;
A traveling control device for a crane for cargo handling, comprising: Storage means for storing a history of the container crane coefficient calculated by the coefficient calculation means;
Average coefficient calculating means for calculating an average container crane coefficient from the history, the starting torque calculating means immediately before the start of traveling of the cargo handling crane, the wind speed in the traveling direction immediately before the start of traveling and the average container crane coefficient And calculating the starting torque from the relational expression using
The traveling control apparatus for a cargo handling crane according to claim 1. The relational expression is an expression of a function in which the torque of the traveling motor is proportional to two wind speeds in the traveling direction, and the container crane coefficient is a proportional constant,
The traveling control device for a crane for cargo handling according to claim 1 or 2.

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