JP7791566B2 - Cargo handling assistance device and control method for cargo handling assistance device - Google Patents

Description

This application claims domestic priority based on an application filed on September 17, 2020. The present invention relates to a loading assistance device used in manufacturing, assembly, transportation, and other processes in the manufacturing field, and relates to a loading assistance device that moves loads up and down with minimal operating force, assisted by a motor, when lifting or lowering loads, and a method for controlling the loading assistance device.

Factory assembly of industrial products has traditionally used loading and unloading equipment to suspend and raise and lower heavy loads such as tools, work equipment, finished products, and semi-finished goods. Some of these loading and unloading devices generate an assisting force, allowing users to lift and lower heavy loads to any height with a light operating force. Loading and unloading devices that generate this type of assisting force use a motor to provide assistance, applying a small operating force (external force) to the load, allowing it to move smoothly. Therefore, unlike devices that simply use an electric motor for up and down movement, they are configured to detect the load of the load and the operating force applied to it using, for example, a load detector, and control the load based on the change in weight due to the application of an external force using an AC servo motor connected to a rotation angle detector.

Japanese Patent Application Laid-Open No. 2019-52007

Patent Document 1 discloses technology in which the control unit maintains balance in response to commands from the operating unit, but there is room for improvement in operability when, for example, a worker suddenly stops a relatively heavy load while it is being moved.

In light of these problems, the present invention aims to provide a cargo handling assistance device and a control method for such a device that improves operability during balanced cargo handling operations.

In order to achieve the above object, a cargo handling assistance device according to one aspect of the present invention comprises:
A cargo handling assistance device that assists in lifting and lowering a cargo, the device having a locking member, a lifting and lowering operating unit, a motor unit, a weight detection unit, a position detection unit, an operation command unit, and a control unit,
The locking member is
Engage the cargo to be lifted and lowered;
The lifting operation unit is
The locking member is raised and lowered by reeling out a link chain or a rope,
The motor unit includes:
Drive the lifting operation unit,
The weight detection unit
Detecting a weight applied to the lifting operation unit and transmitting the weight value to the control unit;
The position detection unit
Detecting the extension position of the locking member and transmitting the position value to the control unit;
The operation command unit
Sending a command to the control unit regarding the raising and lowering of the locking member,
The control unit
a weight registration means for receiving the weight value from the weight detection unit and storing it as a registered weight when a balance control command is received from the operation command unit;
a balance control means for calculating a control value that makes the weight value received from the weight detection unit equal to the registered weight and issuing a command to the motor unit;
a speed control means for controlling the speed at which the cargo is raised and lowered;
a switching means for switching between the balance control means and the speed control means;
It has.

In order to achieve the above object, a cargo handling assistance device according to one aspect of the present invention comprises:
When the control unit detects that the load is being raised or lowered at a predetermined speed or more by the balance control means based on the position value from the position detection unit, and further detects that the weight value received from the weight detection unit is greater than the registered weight when the load is being raised and is smaller than the registered weight when the load is being lowered, the switching unit switches from the balance control means to the speed control means which sets the target speed to zero,
When the control unit detects that the cargo has been stopped by the speed control unit based on the position value from the position detection unit, the switching unit is configured to switch from the speed control unit to the balance control unit.

In order to achieve the above object, a control method for a cargo handling assistance device according to one aspect of the present invention includes:
A control method for a cargo handling assistance device that has a locking member, a lifting/lowering operating unit, a motor unit, a weight detection unit, a position detection unit, an operation command unit, and a control unit and assists in lifting/lowering a cargo, comprising:
The locking member locks the cargo to be lifted and lowered,
The lifting/lowering operation unit raises and lowers the locking member by reeling out the locking member with a link chain or a rope,
The motor unit drives the lifting operation unit,
The weight detection unit detects the weight applied to the lifting operation unit and transmits the weight value to the control unit;
The weight detection unit detects the position of the locking member and transmits the position value to the control unit;
The operation command unit transmits a command to the control unit regarding the raising and lowering of the locking member,
When the control unit receives a balance control command from the operation command unit,
a weight registration step of receiving a weight value from the weight detection unit and storing the weight value as a registered weight;
a balance control step of calculating a control value that makes the weight value received from the weight detection unit equal to the registered weight and issuing the control value to the motor unit;
a speed control step for controlling the speed of lifting and lowering of the cargo;
a switching step of switching between balance control and speed control;
The device is configured to include:

In order to achieve the above object, a control method for a cargo handling assistance device according to one aspect of the present invention includes:
The switching step is
a first switching step in which the control unit detects, based on the position value from the position detection unit, that the cargo is being lifted or lowered at a predetermined speed or faster in the balance control step, and further detects, based on the weight value from the weight detection unit, that the weight value when the cargo is being lifted or lowered at a predetermined speed or faster is greater than the registered weight when the cargo is being lifted and is smaller than the registered weight when the cargo is being lowered; and
Next, the control unit is configured to have a second switching step in which, when it detects based on the position value from the position detection unit that the cargo has stopped due to the speed control step, it switches from the speed control step to the balance control step.

The cargo handling assistance device of the present invention provides a cargo handling assistance device that is easy to operate even when handling relatively heavy cargo.

1 is a perspective view of a cargo handling assistance device and a cargo to be handled according to an embodiment of the present invention; 1 is a perspective view of a main body of a cargo handling assistance device according to an embodiment of the present invention, with a portion thereof omitted, and an enlarged perspective view of a wireless remote control device; 1 is a block diagram of an electronic circuit of a cargo handling assistance device according to an embodiment of the present invention. 1 is a schematic diagram illustrating a first operation using the cargo handling assistance device according to an embodiment of the present invention. FIG. 1 is a schematic diagram illustrating a first operation using the cargo handling assistance device according to an embodiment of the present invention. FIG. 1 is a schematic diagram illustrating a first operation using the cargo handling assistance device according to an embodiment of the present invention. FIG. 1 is a schematic diagram illustrating a first operation using the cargo handling assistance device according to an embodiment of the present invention. FIG. 1 is a schematic diagram illustrating a first operation using the cargo handling assistance device according to an embodiment of the present invention. FIG. FIG. 10 is a schematic diagram illustrating a second operation using the cargo handling assistance device according to the embodiment of the present invention. FIG. 10 is a schematic diagram illustrating a second operation using the cargo handling assistance device according to the embodiment of the present invention. FIG. 10 is a schematic diagram illustrating a second operation using the cargo handling assistance device according to the embodiment of the present invention. FIG. 10 is a schematic diagram illustrating a second operation using the cargo handling assistance device according to the embodiment of the present invention. FIG. 10 is a schematic diagram illustrating a second operation using the cargo handling assistance device according to the embodiment of the present invention. FIG. 10 is a schematic diagram illustrating a second operation using the cargo handling assistance device according to the embodiment of the present invention. 3 is a flowchart executed by a control unit of the cargo handling assistance device according to the embodiment of the present invention. 4 is a time chart of a first operation using the cargo handling assistance device according to the embodiment of the present invention. 10 is a time chart of a second operation using the cargo handling assistance device according to the embodiment of the present invention.

The following provides a detailed description of a cargo handling assistance device according to an embodiment of the present invention, with reference to the drawings. Figure 1 is a perspective view of a cargo handling assistance device 1 and cargo 7, which is an example of an embodiment of the present invention.

The cargo handling assistance device 1 comprises a main unit 2, a locking member 6, and an operation command unit 9. The main unit 2 raises and lowers the locking member 6 and the cargo 7 locked to the locking member 6. The locking member 6 is located below a link chain 4 extending vertically downward from the main unit 2. The operation command unit 9 can remotely control the main unit 2. A hanging hook 3 is provided on the top surface of the main unit 2. Therefore, the main unit 2 can be used by hanging it from a building beam or a moving block 18 that can move horizontally along a horizontal movement rail 8 shown in Figure 4 and subsequent figures.

The locking member 6 is a member that locks the cargo 7 and includes a hanging hook for the cargo attached to one end of the link chain 4. In this embodiment, the cargo 7 is, for example, a rectangular parallelepiped item with an eyebolt attached to the top.

Figure 2 is a perspective view of the main body 2 of the loading assistance device 1 according to an embodiment of the present invention, with a portion thereof omitted, and an enlarged perspective view of the operation command unit 9.

The main unit 2 has a cover, inside which are housed the control unit 10, motor unit 11, lifting/lowering operation unit 16, weight detection unit 12, etc.

The control unit 10 of the main unit 2 is equipped with a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), and other storage devices and input/output devices, and controls the vertical movement of the locking member 6 via the link chain 4. The control unit 10 also includes a circuit that supplies power to the electrical and electronic components that make up the main unit 2.

The motor unit 11 is a drive source for moving the locking member 6 up and down. A reducer is attached to the load side of the motor of the motor unit 11. This motor is, for example, an AC servo motor.

This reducer reduces the motor's rotational speed to a predetermined speed. The reducer may be, for example, a strain wave gear reducer. A strain wave gear reducer consists of a wave generator with an elliptical outer periphery, an elastically deformable flexspline with numerous external teeth formed on its outer periphery that is fitted around the wave generator and whose position changes as it is deflected circumferentially with the rotation of the wave generator, and a circular spline on the outer periphery of the flexspline with internal teeth that engage with the external teeth of the flexspline. Power is then extracted and transmitted to output shaft 15, which connects the flexspline as a rotational output. Using a reducer with minimal backlash, such as a strain wave gear reducer, for this device eliminates uncontrollable areas during frequent forward and reverse motor rotation switching for vertical movement, achieving a smooth operating feel. Note, however, that the reducer is not limited to a strain wave gear reducer.

The output shaft 15 is a rotating shaft that reduces the rotational speed using a reducer and outputs increased torque. It is connected to the lifting/lowering actuator 16 and rotates the lifting/lowering actuator 16 continuously in both forward and reverse directions.

The link chain 4 is a sling made up of intersecting, alternating oval loops consisting of semicircular arc sections and straight sections connected to them. One end of the link chain 4 is connected to the locking member 6, and the other end (the unloaded side) is stored in the chain storage section 17.

The lifting/lowering unit 16 includes a rotating member that rotates when power is transmitted from the motor unit 11, which serves as the drive source. In this embodiment, the rotating member of the lifting/lowering unit 16 is hollow and connected to the output shaft 15 at its hollow portion. The link chain 4 is wound around the outer cylindrical surface, winding and unwinding the link chain 4. The link chain 4 is wound approximately vertically below the hanging hook 3, close to the center of gravity of the main device 2. The link chain 4 is fitted into a pocket groove on the outer cylindrical surface of the lifting/lowering unit 16 and wound approximately 180 degrees. In this embodiment, a link chain 4 is used to connect to the locking member 6 and wind around the lifting/lowering unit 16, but this is not limiting and a wire rope may also be used. When a wire rope is used, the lifting/lowering unit 16 is drum-shaped, and one end of the wire rope is fixed and wound around the rotating member.

The position detection unit 13 is connected to the anti-load side of the motor unit 11. The position detection unit 13 detects the rotational angle position of the motor. The position detection unit 13 is a so-called absolute encoder that optically detects the rotational angle position of the motor and transmits the position value to the control unit 10. Therefore, this position detection unit 13 can detect the extension position of the locking member 6, i.e., the elevation position of the locking member 6.

The weight detection unit 12 is equipped with a strain element and a strain gauge attached to the strain element. The strain element has a shape that allows it to elastically deform so that it can detect the force transmitted from the link chain 4 wrapped around the lifting/lowering unit 16. The strain gauge is incorporated into a Wheatstone bridge circuit that converts the strain generated in the strain element in response to weight into an electrical signal, and the weight detection unit 12 detects the weight applied to the lifting/lowering unit 16 and transmits the weight value to the control unit 10.

The control unit 10 of the main unit 2 is located near the lifting/lowering actuator 16 inside the main unit 2. The control unit 10 of the main unit 2 receives position values from the position detection unit 13 and weight values from the weight detection unit 12, performs calculations based on these values, and controls the motor unit 11. The electrical components associated with the control unit 10 of the main unit 2 are located inside a cover, allowing the main unit 2 to be used in places where it is exposed to powder or water droplets.

In this embodiment, the position detection unit 13 is located on the anti-load side of the motor unit 11, but this is not limited to this. It may also be located on the output shaft 15, which is the output of the reducer, or on the lifting operation unit 16, or on both. Furthermore, the position detection unit 13 is not limited to an optical type, and may also be a magnetic type, a capacitance type, etc.

Furthermore, the weight detection unit 12 only needs to be able to detect the weight applied to the lifting operation unit 16, and may be a rotary type structure that detects torque from the twist of a rotating shaft located between the reducer and the lifting operation unit 16, or a flange or drum-shaped structure that detects the reaction force received by the motor unit 11. Furthermore, the weight detection unit 12 is not limited to a strain gauge type, and may also be a magnetostrictive type, a capacitance type, etc.

The main unit transmitter/receiver 14 is arranged alongside the circuit board of the control unit 10 of the main unit 2. The main unit transmitter/receiver 14 has electronic circuitry for wireless communication with the operation command unit 9.

The operation command unit 9 is used to remotely operate the main unit 2, and in this embodiment, communicates via radio waves. The operation command unit 9 is battery-powered. The operation command unit 9 has operation means such as a balance button 21, a hold button 22, an up button 23, and a down button 24.

Figure 3 is a block diagram of the electronic circuitry of the cargo handling assistance device 1 according to an embodiment of the present invention. The cargo handling assistance device 1 includes a main unit 2 and an operation command unit 9.

The control unit 10 of the main unit 2 controls the entire main unit 2. The control unit 10 of the main unit 2 includes a drive circuit that drives the motor unit 11. The control unit 10 of the main unit 2 receives the weight value applied to the lifting/lowering actuator 16 from the weight detection unit 12, receives the position value of the rotation angle of the motor unit 11 from the position detection unit 13, and transmits and receives signals with the main unit transceiver unit 14. The main unit transceiver unit 14 and the control unit 10 of the main unit 2 are connected by wire, and transmit and receive signals at high speeds and at extremely short time intervals. Details of the weight registration means 10a, balance control means 10b, speed control means 10c, and switching means 10d within the control unit 10 will be described later.

The main device transmitter/receiver 14 communicates wirelessly with the operation command transmitter/receiver 25 of the operation command unit 9. The main device transmitter/receiver 14 and operation command transmitter/receiver 25 are composed of electronic circuits that perform wireless communication, and may include a radio wave transmitter and receiver, as well as a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), etc.

The operation command control unit 20 controls the entire operation command unit 9. The operation command control unit 20 receives operation commands from each operation means (operation button) and transmits operation command signals to the operation command transmission/reception unit 25. The operation command transmission/reception unit 25 then wirelessly transmits the operation commands received from the operation command control unit 20 to the main unit transmission/reception unit 14. The signal containing this command is assigned with identification information for the operation command unit 9, which pairs the operation command unit 9 with the main unit 2.

Next, we will explain the role of each operation button, which is an operation means provided on the operation command unit 9. Each operation button is, for example, a push switch. When the operator presses the balance button 21, a balance command is sent from the operation command unit 9, which is received by the control unit 10 of the main unit 2 and transitions to balance control. That is, the control unit 10 of the main unit 2 stores the weight value detected by the weight detection unit 12 and output as a registered weight using the weight registration means 10a. The balance control means 10b calculates a control value that zeros the difference between the registered weight and the weight applied to the lifting/lowering unit 16, and controls the motor unit 11 accordingly. This control is referred to as balance control in the present invention, and the state of the locking member 6 and the cargo 7 during this balance control is referred to as a balanced state. In other words, balance control is the process by which the control unit 10 of the main unit 2 calculates a control value and controls the motor unit 11 so that the tension in the link chain 4 generated by the registered weight is equal to the tension in the link chain 4 generated by the weight detected by the lifting/lowering unit 16. If the worker applies a vertically downward external force to the locking member 6 and the load 7 during this balance control, the weight applied to the lifting actuator 16 increases. Therefore, the control unit 10 of the main unit 2 calculates a control value to bring this weight closer to the registered weight and controls the motor unit 11 in the direction of unwinding the link chain 4, causing the locking member 6 and the load 7 to descend. On the other hand, if the worker applies a vertically upward external force to the locking member 6 and the load 7 during this balance control, the weight applied to the lifting actuator 16 decreases. Therefore, the control unit 10 of the main unit 2 calculates a control value to bring this weight closer to the registered weight and controls the motor unit 11 in the direction of winding up the link chain 4, causing the locking member 6 and the load 7 to ascend. When the worker stops applying the external force, the weight detected by the weight detection unit 12 becomes equal to the registered weight, causing the locking member 6 and the load 7 to come to a standstill. This control value may include, for example, acceleration.

On the other hand, when the operator presses the hold button 22, the control unit 10 of the main unit 2 performs calculations in response to this and controls the motor unit 11 to hold the lifting actuator 16 in its current position, i.e., to keep the lifting positions of the locking member 6 and the cargo 7 constant; this is referred to as hold control in the present invention.

When the operator presses the up button 23 or down button 24, the control unit 10 of the main unit 2 responds by controlling the motor unit 11 to raise or lower the locking member 6. By repeatedly pressing the up button 23 or down button 24, the operator can continuously raise or lower the locking member 6 and the cargo 7 using the motor unit 11. Whether the main unit 2 is performing holding control or balance control, pressing the up button 23 or down button 24 will cause it to rise or fall, and releasing the pressed up button 23 or down button 24 will return it to the previous holding control or balance control. Therefore, when the operator presses the up button 23 or down button 24 to forcibly move the locking member 6 and the cargo 7, the control unit 10 of the main unit 2 is in forced movement control.

Figures 4 to 8 are schematic diagrams showing a first series of work states in which a worker uses the cargo handling assistance device 1 according to an embodiment of the present invention to handle a cargo object 7. Figures 9 to 14 are schematic diagrams showing a second series of work states in which a worker uses the cargo handling assistance device 1 according to an embodiment of the present invention to handle a cargo object 7. Figure 15 is a flowchart executed by the control unit 10 of the main unit 2 of the cargo handling assistance device 1 according to an embodiment of the present invention. The movements of the locking member 6 and the cargo object 7 and each step of the control method executed by the control unit 10 of the main unit 2 at that time will be described using Figures 4 to 15.

In Figure 4, rail 8 is a track rail installed horizontally on the ceiling or other surface of the work premises. Mobile block 18 is a member that can move approximately horizontally along rail 8 and is connected to hanging hook 3 to suspend main unit 2. Therefore, mobile block 18 allows main unit 2 to move freely horizontally. Shelf 33 is fixedly installed on floor 31. Furthermore, shelf 34 is fixedly installed on floor 32, which is stepped vertically from floor 31.

The method for moving the cargo 7 placed on the floor 31 to the shelf 34 will now be described. In Figure 15, first, as a preparation step, the operator turns on the power switch (not shown) of the main unit 2, which starts up the control unit 10 of the main unit 2. The control unit 10 of the main unit 2 executes step S101 and proceeds to step S102. In step S101, the control unit 10 of the main unit 2 holds the lifting actuator 16 in its current position. In the state shown in Figure 4, the operator presses the down button 24 of the operation command unit 9 to lower the locking member 6, moving it to a position where it can lock the cargo 7. At this time, tension is applied to the lifting actuator 16 only from the weight of the link chain 4 and the weight of the locking member 6.

Figure 5 shows the state in which the worker has moved the locking member 6 vertically downward from the position shown in Figure 4, locking the locking member 6 to the cargo 7.

Next, the operator presses the up button 23 on the operation command unit 9 to raise the locking member 6, as shown in Figure 6. In Figure 15, the control unit 10 of the main unit 2 determines in step S102 that the up button 23 has been pressed and executes step S103. In step S103, the control unit 10 of the main unit 2 activates the lifting operation unit 16 to raise the locking member 6 and the cargo 7, and then returns to step S101 to perform control to hold them in that position. If the operator continues to press the up button 23, the control unit 10 of the main unit 2 continues step S103 to raise the locking member 6 and the cargo 7.

When the locking member 6 is raised by the lifting operation unit 16 winding up the link chain 4 and the cargo 7 is lifted off the floor 31 and suspended in mid-air, the operator stops pressing the lift button 23 and the control unit 10 of the main unit 2 executes holding control. This state is shown in Figure 6. Next, when the operator presses the balance button 21, the control unit 10 of the main unit 2 detects in step S104 that the balance button 21 has been pressed (Yes) and proceeds to step S105. If the operator has not pressed the balance button 21, the control unit 10 of the main unit 2 detects in step S104 that the balance button 21 has not been pressed (No) and returns to step S101 to maintain holding control.

In step S105 (weight registration step), the weight registration means 10a within the control unit 10 of the main unit 2 registers and stores the weight value detected and output by the weight detection unit 12 when it detects the weight applied to the lifting operation unit 16.

In step S106 (balance control step), the control unit 10 of the main unit 2 performs balance control on the locking member 6 and the cargo 7 based on the registered and stored weight values. In this state, the worker can raise or lower the cargo 7 by applying an external force to the locking member 6 or the cargo 7.

In step S106 (balance control step), the control unit 10 of the main unit 2 executes balance control while proceeding to step S107. The worker then raises the cargo 7 by continuously applying a vertically upward external force to the locking member 6 or the cargo 7.

If the operator presses the hold button 22 here, the control unit 10 of the main unit 2 determines in step S107 that the hold button 22 has been pressed (Yes), and proceeds to hold control, releasing the balance control and maintaining the position. If the control unit 10 of the main unit 2 determines in step S107 that the hold button 22 has not been pressed (No), the process proceeds to step S108.

In step S108, the control unit 10 of the main unit 2 determines whether the locking member 6 and the cargo 7 are rising or falling at a predetermined speed or greater. If the control unit 10 of the main unit 2 determines in step S108 that the locking member 6 and the cargo 7 are not rising or falling at a predetermined speed or greater (No), it continues executing balance control. On the other hand, if the control unit 10 of the main unit 2 determines in step S108 that the locking member 6 and the cargo 7 are rising or falling at a predetermined speed or greater (Yes), it proceeds to step S109. This predetermined speed can be variably set depending on the weight of the cargo being handled and the nature of the work, and can be set in advance by the equipment manager, etc.

In step S109, the control unit 10 of the main unit 2 determines whether or not there has been a weight change based on the weight value from the weight detection unit 12. In Figure 6, the worker is attempting to lift the load 7, applying a vertically upward external force to the load 7. This causes the net weight value applied to the weight detection unit 12 to decrease and become smaller than the registered weight value registered in S105 (weight registration step). The control unit 10 of the main unit 2 uses the balance control means 10b to calculate a control value that eliminates the difference between the registered weight and the weight applied to the lifting actuator 16, and controls the motor unit 11. Therefore, at a macro level, the weight value transmitted by the weight detection unit 12 converges to the registered weight value. However, at a micro level, the weight detection unit 12 transmits a decreased weight value. Then, as shown in Figure 7, when the worker applies a vertically downward external force to stop the load 7, the net weight value applied to the weight detection unit 12 changes to a value larger than the registered weight value registered in S105 (weight registration step). The control unit 10 of the main unit 2 uses the balance control means 10b to calculate a control value that will reduce the difference between the registered weight and the weight applied to the lifting operation unit 16 to zero, and controls the motor unit 11. Therefore, on a macro level, the weight value transmitted by the weight detection unit 12 converges to the registered weight value, but on a micro level, the weight detection unit 12 transmits an increased weight value. Therefore, in step S109, the control unit 10 of the main unit 2 determines that there has been a weight change that crosses the registered weight value (Yes) and proceeds to step S110.

The criteria for determining this weight change are determined by the amount of change and its duration, and can be set variably depending on the weight of the cargo being handled and the nature of the work, and can be set in advance by the equipment manager, etc.

If the control unit 10 of the main unit 2 determines in step S109 that there is no weight change that crosses the registered weight value (No), it returns to step S106 and continues to perform balance control.

In step S110 (first switching step), the control unit 10 of the main unit 2 switches from balance control to speed control using the switching means 10d, and then proceeds to step S111.

In step S111 (speed control step), the control unit 10 of the main unit 2 executes speed control to set the target speed of the movement of the cargo 7 to zero, and then proceeds to step S112. The control unit 10 of the main unit 2 also widens the upper limit of the acceleration command compared to balance control, controlling the cargo 7 to stop as quickly as possible. This upper limit of the acceleration command is variable and can be set in advance by the equipment administrator, etc.

In step S112, the control unit 10 of the main unit 2 determines whether the movement speed of the cargo 7 has reached zero. More specifically, the control unit 10 of the main unit 2 calculates the movement speed of the cargo 7 based on the position value from the position detection unit 13 and determines whether the target zero speed has been reached. If the control unit 10 of the main unit 2 determines in step S112 that the movement speed of the cargo 7 has not reached zero (No), the control unit 10 returns to step S111 and continues speed control. If the control unit 10 of the main unit 2 determines in step S112 that the movement speed of the cargo 7 has reached zero (Yes), the control unit 10 proceeds to step S113.

In step S113 (second switching step), the control unit 10 of the main unit 2 quickly switches from speed control to balance control using the switching means 10d, and proceeds to step S106, where the control unit 10 of the main unit 2 performs balance control. This balance control is performed based on the weight value stored in the previously executed step S105.

If the operator presses the hold button 22 during balance control, the control unit 10 of the main unit 2 determines in step S107 that the hold button 22 has been turned ON, exits balance control, and executes step S101 to hold the position. In this embodiment, step S107 is performed immediately after step S106, but it is not limited to this and may be performed by interrupt processing at any state during balance control. When performing balance control again from hold control, the operator presses the balance button 21, which executes step S105, registering the weight and placing the cargo 7 in a balanced state.

As shown in Figure 7, after the worker stops the load 7, the load 7 remains balanced, allowing the worker to move the load 7 horizontally to the right until it is directly above the shelf 34 (Figure 8). The worker then presses the hold button 22 to hold the load 7 in place, and continues to press the lowering button 24 to land the load 7 on the shelf 34, continuing to press the lowering button 24 until it reaches a position where the locking member 6 can be released from the load 7. This loosens the link chain 4, allowing the worker to release the locking member 6 from the load 7 and completing the first operation.

Next, using Figures 9 to 14, we will explain a second method for moving the object 7 placed on the floor 32 to the shelf 33. The operator starts the control unit 10 of the main unit 2, and if the holding control is not in progress, presses the holding button 22 to place the locking member 6 in a holding state (Figure 9). Then, the operator presses the down button 24 as appropriate to move the locking member 6 to a vertical position where it can lock the object 7. The operator then locks the locking member 6 to the object 7 (Figure 10).

Next, if the operator continues to press the lift button 23, the control unit 10 of the main unit 2 continues step S103 and lifts the locking member 6 and the cargo 7.

The locking member 6 rises as the lifting actuator 16 winds up the link chain 4, the cargo 7 leaves the floor 32, and when the worker stops pressing the lift button 23, the control unit 10 of the main unit 2 executes holding control. This state is shown in Figure 11.

When the worker presses the balance button 21, the control unit 10 of the main unit 2 determines whether the balance button 21 has been turned ON, and if it determines that the balance button 21 has been pressed (Yes), proceeds to step S105.

Since the steps S105 to S113 executed by the control unit 10 of the main unit 2 are the same, only the different operations and the related steps will be explained.

The control unit 10 of the main unit 2 executes step S106, and the load 7 is in a balance control state, allowing the worker to freely raise and lower the load 7. The worker then moves the load 7 horizontally to the left, and then continues to apply a vertically downward external force to the locking member 6 or the load 7 (Figure 12). This causes the load 7 to move vertically downward.

At this time, in step S109, the control unit 10 of the main unit 2 determines whether or not there has been a weight change based on the weight value from the weight detection unit 12. In Figure 12, the worker is attempting to lower the cargo 7, so a vertically downward external force is applied to the cargo 7. As a result, the weight value detected by the weight detection unit 12 increases and becomes larger than the registered weight value registered in S105 (weight registration step). Then, as shown in Figure 13, when the worker applies a vertically upward external force to stop the cargo 7, the weight value detected by the weight detection unit 12 changes to a value smaller than the registered weight value registered in S105 (weight registration step). Therefore, in step S109, the control unit 10 of the main unit 2 determines that there has been a weight change across registered weight values (Yes) and proceeds to step S110 (first switching step).

When the worker applies a vertically upward external force to the cargo 7 at the desired position to stop it, the cargo 7 is stopped via speed control, and control is quickly switched in step S113 (second switching step), and the cargo 7 is rebalanced in step S106. The worker can then move the cargo 7 horizontally to the left, moving it directly above the shelf 33 (Figure 14). The worker then presses the hold button 22 to hold the position of the cargo 7, and continues to press the lowering button 24 to land the cargo 7 on the shelf 33, continuing to press the lowering button 24 until the cargo 7 is at a position where it can be released from the locking member 6. This loosens the link chain 4, allowing the worker to release the locking member 6 from the cargo 7, completing the second operation.

Figure 16 is a time chart for the first task using the loading assistance device according to an embodiment of the present invention. From top to bottom, Figure 16 shows the pressed state of each button (balance button 21, up button 23, down button 24, hold button 22), the control state of the control unit 10 of the main device 2, the registered and stored weight, the detected weight detected by the weight detection unit 12, and the speed v of the suspended load (upward speed is positive, downward speed is negative). Because the task performed by the worker is not performed on a fixed time axis, this time chart schematically shows the state of each operating button and the device. The state of the loading assistance device 1 will be explained using Figure 16 in accordance with the first task shown above.

The control unit 10 of the main unit 2 starts holding control when the power is turned ON. In this example, the registered weight is cleared to zero when the power is turned OFF. The weight detected by the weight detection unit 12 is W1. This weight is the sum of the weights of the link chain 4 and the locking member 6. Furthermore, since holding control is in progress, the speed is zero.

Next, when the worker presses the down button 24 between times t1 and t2, the locking member 6 descends at a speed Vn. Then, when the worker locks the locking member 6 to the cargo 7 and presses the up button 23 between times t3 and t4, the locking member 6 ascends at a speed Vm, and the detected weight gradually increases until it reaches W2.

Next, when the worker presses the balance button 21, the detected weight W2 is stored as the registered weight, and the control unit 10 of the main unit 2 transitions to balance control (time t5). When the worker applies a vertically upward external force to the locking member 6 or the cargo 7, the detected weight decreases, so the control unit 10 of the main unit 2 controls the motor unit 11 so that the detected weight becomes the registered weight W2. During this balance control, the control unit 10 controls the detected weight so that the registered weight W2 becomes the registered value when the worker applies an external force, so although the detected weight fluctuates microscopically, it is controlled to maintain it at a nearly constant W2. However, if the movement speed is limited by the external force applied by the worker, the detected weight may not be maintained at W2 and may become close to the net weight.

The control unit 10 of the main unit 2 then calculates the speed by differentiating the position value from the position detection unit 13, and when it detects that the cargo 7 is rising at a speed equal to or greater than the predetermined speed Vu and the weight value received from the weight detection unit 12 has increased from the registered weight W2 (time t6), it switches from the balance control unit 10b to the speed control unit 10c, which targets a speed of zero, using the switching means 10d. Thereafter, when the speed of the cargo 7 reaches zero based on the position value from the position detection unit 13, the control unit 10 of the main unit 2 switches back to the balance control unit 10b (time t7).

When the operator presses the hold button 22 at time t8, the control unit 10 of the main unit 2 switches to hold control. Next, when the operator presses the lowering button 24 between time t9 and time t10, the locking member 6 descends at speed Vn. At the same time, the detected weight decreases from W2 to W1. When the detected weight reaches W1, the load 7 can be released from the locking member 6.

Figure 17 is a time chart for the second task using the cargo handling assistance device according to an embodiment of the present invention. Because the tasks performed by the worker are not performed on a fixed time axis, this time chart also shows the state of each operation button and device schematically. The state of the cargo handling assistance device 1 will be explained using Figure 17 in accordance with the second task shown above. Note that the period from time t0 to time t5 and from time t8 onwards are almost the same as the first task, so they will be omitted.

When the worker presses the balance button 21, the detected weight W2 is stored as the registered weight, and the control unit 10 of the main unit 2 transitions to balance control (time t5). When the worker applies a vertically downward external force to the locking member 6 or the cargo 7, the detected weight increases, so the control unit 10 of the main unit 2 controls the motor unit 11 so that the detected weight becomes the registered weight W2. During this balance control, when the worker applies an external force, the control unit 10 controls the detected weight so that it becomes the registered weight W2, so although the detected weight fluctuates microscopically, it is maintained at a nearly constant W2.

The control unit 10 of the main unit 2 then calculates the speed by differentiating the position value from the position detection unit 13, and when it detects that the cargo 7 is descending at a predetermined speed Vd or faster and the weight value received from the weight detection unit 12 has increased from the registered weight W2 (time t6), it switches from the balance control unit 10b to the speed control unit 10c, which targets a speed of zero, using the switching unit 10d. Thereafter, when the speed of the cargo 7 reaches zero based on the position value from the position detection unit 13, the control unit 10 of the main unit 2 switches back to the balance control unit 10b (time t7).

As explained above, with the cargo handling assistance device of the present invention, when a relatively heavy load is being raised or lowered in a balanced state, the worker can quickly stop the load near the desired position and instantly return to balance control, thereby achieving crisp and comfortable operability and providing a cargo handling assistance device and control method therefor with improved operability.

The present invention has been described based on preferred embodiments, but the present invention is not limited to the above-described embodiments and various modifications are possible without departing from the spirit of the invention.

One example of how this invention can be used is as a loading assistance device that assists in the movement of cargo.

1: cargo handling assistance device 2: main body device 3: hanging hook 4: link chain 6: engaging member 7: cargo handling object 8: rail 9: operation command unit 10: control unit (main body device control unit)
10a: Weight registration means 10b: Balance control means 10c: Speed control means 10d: Switching means 11: Motor section 12: Weight detection section 13: Position detection section 14: Main device transmission/reception section 15: Output shaft 16: Lifting operation section 17: Chain storage section 18: Moving block 20: Operation command control section 21: Balance button 22: Hold button 23: Up button 24: Down button 25: Operation command transmission/reception section 31: Floor 32: Floor 33: Shelf 34: Shelf

Claims (2)

A cargo handling assistance device that assists in lifting and lowering a cargo, the device having a locking member, a lifting and lowering operating unit, a motor unit, a weight detection unit, a position detection unit, an operation command unit, and a control unit,
The locking member is
Engage the cargo to be lifted and lowered;
The lifting operation unit is
The locking member is raised and lowered by reeling out a link chain or a rope,
The motor unit includes:
Drive the lifting operation unit,
The weight detection unit
Detecting a weight applied to the lifting operation unit and transmitting the weight value to the control unit;
The position detection unit
Detecting the extension position of the locking member and transmitting the position value to the control unit;
The operation command unit
Sending a command to the control unit regarding the raising and lowering of the locking member,
The control unit
a weight registration means for receiving the weight value from the weight detection unit and storing it as a registered weight when a balance control command is received from the operation command unit;
a balance control means for calculating a control value that makes the weight value received from the weight detection unit equal to the registered weight, issuing a command to the motor unit, and controlling the motor unit to lower or raise the cargo based on the control value;
a speed control means for controlling the speed of the lifting and lowering of the cargo to set a target speed of the lifting and lowering of the cargo to zero from the lowering or the lifting under the control of the balance control means;
a switching means for performing a first switching from the balance control means to the speed control means or a second switching from the speed control means to the balance control means;
and
The first switching by the switching means includes:
When the control unit detects that the cargo is being raised or lowered at a predetermined speed or more by the balance control means based on the position value from the position detection unit, and further detects that the weight value received from the weight detection unit is greater than the registered weight when the cargo is raised and is smaller than the registered weight when the cargo is lowered,
The second switching by the switching means is
The control unit detects that the cargo has been stopped by the speed control means based on the position value from the position detection unit.
A loading and unloading assistance device characterized by the above. A control method for a cargo handling assistance device that has a locking member, a lifting/lowering operating unit, a motor unit, a weight detection unit, a position detection unit, an operation command unit, and a control unit and assists in lifting/lowering a cargo, comprising:
The locking member is
Engage the cargo to be lifted and lowered;
The lifting operation unit is
The locking member is raised and lowered by reeling out a link chain or a rope,
The motor unit includes:
Drive the lifting operation unit,
The weight detection unit
Detecting a weight applied to the lifting operation unit and transmitting the weight value to the control unit;
The weight detection unit
Detecting the extension position of the locking member and transmitting the position value to the control unit;
The operation command unit
Sending a command to the control unit regarding the raising and lowering of the locking member,
The control unit
When a balance control command is received from the operation command unit,
a weight registration step of receiving the weight value from the weight detection unit and storing it as a registered weight;
a balance control step of calculating a control value that makes the weight value received from the weight detection unit equal to the registered weight and issuing the control value to the motor unit;
a speed control step of controlling the speed of lifting and lowering the cargo;
a switching step of switching between the balance control and the speed control;
Including,
The switching step includes:
The control unit
a first switching step of detecting, based on the position value from the position detection unit, that the cargo is ascending or descending at a predetermined speed or more in the balance control step, and further detecting, based on the weight value from the weight detection unit, that the weight value when ascending or descending at the predetermined speed or more is greater than the registered weight when the cargo is ascending and is less than the registered weight when the cargo is descending; and
Next, the control unit
a second switching step of switching from the speed control step to the balance control step when it is detected based on the position value from the position detection unit that the cargo has stopped due to the speed control step;
A method for controlling a loading and unloading assistance device having the above structure.