JP2021116154A - Parallel wire mechanism - Google Patents

Abstract

To provide a parallel wire mechanism capable of easily moving a work object over a wide area in a direction of force applied to the work object.SOLUTION: A parallel wire mechanism 1 includes: a plurality of wires; a plurality of winches 6; a work object; a sensor 11 for measuring force applied to the work object; a first calculation unit 12 for calculating at least any one of a target position, a target speed, and target acceleration of the work object by calculating at least any one of virtual inertia, viscosity, and spring constant based on the force measured by the sensor 11; a second calculation unit 13 for calculating a pay-out length of each wire for moving the work object according to at least any one of the target position, the target speed, and the target acceleration for each motor 7 of each winch 6; and an output unit 14 for outputting a command value of the pay-out length to the motor 7 of each winch 6.SELECTED DRAWING: Figure 3

Description

The present disclosure relates to a parallel wire mechanism for suspending a work object and moving the work object.

Conventionally, various devices have been known as devices for suspending a work object and moving the work object. Patent Document 1 describes a hoist provided with a cylinder for balance. The hoist extends vertically downward from the drum, with a plurality of guide rollers rolling along the guide rails, and a drum connected to the plurality of guide rollers vertically below the guide rollers via vertical plates and supports. It includes a wire to be pulled out and a hook attached to the lower end of the wire. In this hoist, after hooking an object on a hook, a wire is wound around a drum to raise the object, and in this state, a plurality of guide rollers are rolled along a guide rail to move the object in place. Let me.

Patent Document 2 describes a balancer that moves a load suspended from a hook. The balancer consists of a strut that stands on a pedestal with wheels, a rod-shaped arm that can rotate horizontally at the top of the strut, a trolley that moves along the arm and extends vertically downward from the arm, and a trolley. It is provided with a moving pulley provided at the lower end and a hook extending vertically downward from the moving pulley.

The balancer further comprises a hoist located opposite the arm of the strut and a chordee extending from the hoist along the arm and connected to a trolley and a moving pulley. The hoist has a drum connected to the arm via a chordee and a hoist body located at the bottom of the drum. When the drum is rotated with the load hooked on the hook, the hook is lifted by the winding of the chordee, and the load is lifted. By moving the trolley along the arm in this state, the load is moved to a predetermined place.

Jikkai Sho 58-71094 Jitsuto 3027081 Gazette

In hoists and balancers as described above, it is possible to hook an object on a hook and move the object along a guide rail or an arm. However, in the hoist described above, an object can be moved only within the range where the guide rail is laid. Further, in the balancer described above, there may be a problem that an object can be moved only within the moving range of the arm.

In the balancer described above, although the pedestal is provided on the pedestal on which the columns extend, the pedestal may not be easily moved depending on the situation at the construction site. For example, if the ground or floor of the site has irregularities or steps, the dolly cannot be easily moved. Therefore, when the hoist or balancer described above is used, there is a problem that the load can be moved in a narrow range, but the load cannot be easily moved in a wide range. In particular, at construction sites, there may be a request to move a work object over a wide area, but the current situation is that the work object cannot be easily moved over a wide area.

An object of the present disclosure is to provide a parallel wire mechanism capable of easily moving a work object over a wide area in a direction in which a force is applied to the work object.

The parallel wire mechanism according to the present disclosure includes a plurality of wires installed at a construction site, a plurality of winches provided on each of the plurality of wires and having a motor for winding and winding each wire, and a plurality of wires. At least one of a work object that is connected and supported by multiple wires, a sensor that measures the force applied to the work object, and a virtual inertial, viscous, or spring constant based on the force measured by the sensor. The first calculation unit that calculates one of them to calculate at least one of the target position, target speed, and target acceleration of the work object, and the work object moves at at least one of the target position, target speed, and target acceleration. A second calculation unit that calculates at least one of the unwinding length, unwinding speed, and unwinding acceleration of each wire for each winch motor, and the unwinding length, unwinding speed, and unwinding acceleration. It includes an output unit that outputs at least one command value to the motor of each winch.

This parallel wire mechanism includes a plurality of wires, a work object connected to the plurality of wires, and a plurality of winches provided on each of the plurality of wires and having a motor for unwinding and winding each wire. , The work object moves by unwinding and winding each wire of the motor in each winch. Therefore, the work object can be moved by unwinding and winding each wire in the area surrounded by the plurality of wires, so that the work object can be easily moved. Further, since the entire movable range of the work object can be set in the three-dimensional space formed by the plurality of wires, the work object can be moved over a wide range. In addition, this parallel wire mechanism only needs to include a plurality of wires and a plurality of winches having a motor, and the above-mentioned heavy equipment such as a guide rail and an arm can be eliminated, so that the parallel wire mechanism can be used. Can be easily installed and replaced. Therefore, by easily installing and replacing the parallel wire mechanism at a construction site in a wide area, the work object can be easily moved in a wide area. Furthermore, since the force applied to the work object can be measured by the sensor and the work object can be moved based on the measured force, the operator can intuitively move the work object by applying the force to the work object. Can be moved.

Further, the first calculation unit may change the spring constant according to the location of the work object. In this case, by changing the spring constant when the work object approaches a place where it is not preferable to approach, it is possible to make it difficult for the work object to approach the place. Therefore, by changing the spring constant, it is possible to generate a repulsive force that makes it difficult for the work object to approach the preset movable limit region or obstacle. As a result, even if the work object tries to approach the movable limit area or an obstacle due to an operation error or the like, the repulsive force can prevent the approach, so that the safety of work at the construction site can be improved. Can be enhanced.

Further, the first calculation unit cancels the gravity of the work object and calculates one of the target position, the target speed, and the target acceleration, and the first calculation unit does not cancel a part of the gravity of the work object. The calculation may be performed. In this case, the first calculation unit cancels the gravity of the work object and calculates one of the target position, the target speed, and the target acceleration. However, when the work object is placed on the ground or the floor, the first calculation unit performs the calculation without canceling a part of the gravity of the work object. Therefore, by not canceling a part of the gravity, a part of the gravity of the work object is given to the ground or the floor surface, for example, in a situation where the work object placed on the ground or the floor surface is desired to be moved. It will be. As a result, a desired load can be applied to the ground or the floor surface, and the load can be reduced by a required amount.

According to the present disclosure, the work object can be easily moved over a wide area in the direction in which the force is applied to the work object.

It is a figure which shows typically the construction site to which the parallel wire mechanism which concerns on this embodiment is applied. Each of (a) and (b) is a diagram schematically showing a parallel wire mechanism according to a modified example. It is a block diagram which shows the function of the parallel wire mechanism of FIG. It is a block diagram which shows various calculations performed by the parallel wire mechanism of FIG. It is a figure which shows typically the calculation of the unwinding length of a wire by the parallel wire mechanism of FIG. It is a figure for demonstrating the potential method performed by the parallel wire mechanism which concerns on a modification. It is a block diagram which shows various calculations performed by the parallel wire mechanism of FIG. It is a figure which shows typically the construction site to which the parallel wire mechanism which concerns on a further modification is applied.

Hereinafter, embodiments of the parallel wire mechanism according to the present disclosure will be described with reference to the drawings. In the description of the drawings, the same or corresponding elements are designated by the same reference numerals, and duplicate description will be omitted as appropriate. In addition, the drawings may be partially simplified or exaggerated for the sake of easy understanding, and the dimensional ratio and the like are not limited to those described in the drawings.

FIG. 1 shows the parallel wire mechanism 1 according to the present embodiment and the construction site A to which the parallel wire mechanism 1 is applied. The parallel wire mechanism 1 includes a plurality of wires 5 that support the work object T. In the present disclosure, the "work object" refers to a material used in work performed at a construction site. The construction site A may be, for example, a place where special equipment is required or where it is difficult for people to enter. Even in such a place, the parallel wire mechanism 1 can freely move the work object T by using the wire 5. It is possible to move to.

The parallel wire mechanism 1 is, for example, a three-dimensional suspended parallel wire mechanism provided at the construction site A as shown in FIG. 1, and moves the work object T to a desired position by the balancer control described later. That is, the parallel wire mechanism 1 can be used as a wide area balancer device capable of moving the work object T over a wide area. For example, the work object T moves by being pulled or pushed by the worker M (see FIG. 2A or FIG. 2B) to apply a force. As an example, the worker M pulls the kaishakunin rope to move the work object T.

It should be noted that the present invention is not limited to FIG. 1 in which the four wires 5 are provided, and may be a suspended parallel wire mechanism in which the number of wires 5 is three, as shown in the modified example of FIG. 2 (a). Further, as shown in the modified example of FIG. 2B, a two-dimensional suspension type parallel wire mechanism including two wires 5 may be used. As an example, the worker M may move the work object T by the remote controller.

As shown in FIG. 1, the parallel wire mechanism 1 includes, for example, a plurality of pillars 2, a plurality of sheaves 3 attached to each of the plurality of pillars 2, and a plurality of sheaves 3 located below each of the plurality of pillars 2. A winch 6 and a plurality of wires 5 extending upward from each winch 6 and hung on the sheave 3 are provided. The pillar 2 and the sheave 3 may be provided in advance at the construction site A, for example.

Each of the plurality of sheaves 3 is attached to, for example, the upper end of each pillar 2. Further, the sheave 3 may be attached to something other than the pillar 2. As an example, the number of sets of the pillar 2, the sheave 3, the wire 5, and the winch 6 is four. However, the number of columns 2, sheaves 3, wires 5, and winches 6 is not limited as long as it is 3 or more, and can be changed as appropriate. Further, instead of the example shown in FIG. 1, when the main body of the winch is provided on the upper part of the pillar 2, the sheave 3 can be eliminated.

The pillar 2 is, for example, H steel. However, the type of the column 2 may be, for example, a steel pipe column, and can be changed as appropriate. In a plan view, the plurality of wires 5 extend from each sheave 3 to the inside of the region surrounded by the plurality of pillars 2 and intersect each other at the binding point P. Further, the plurality of wires 5 extend diagonally downward from each sheave 3 toward the binding point P due to the gravity of the work object T.

A work object T, which is a suspended load, is suspended from the binding points P of the plurality of wires 5 via, for example, a hook F and a string B. The work object T is, for example, a transportation object (material) to be transported at the construction site A. The work object T is not limited to the material, and may be an end effector of a robot, a camera for photographing the construction site A, or various inspection devices for inspecting the construction site A, and the type of the work object T is It can be changed as appropriate.

FIG. 3 is a block diagram showing the functions of the parallel wire mechanism 1. As shown in FIGS. 1 and 3, each winch 6 includes a motor 7 that unwinds and winds each wire 5. By unwinding and winding each wire 5 by each motor 7 of each winch 6, it is possible to move the work object T to a desired position within the range of the area surrounded by the plurality of pillars 2. Is.

The parallel wire mechanism 1 assists, for example, when the worker M applies a force to the work object T to move it. For example, the parallel wire mechanism 1 includes a plurality of (for example, four) sensors 11 provided for each wire 5, a control unit 10, and a plurality of winches 6 in which a motor 7 is built.

Each of the plurality of sensors 11 measures the external force applied to the work object T. As the sensor 11, for example, a tension sensor provided on the sheave 3 and measuring the tension of the wire 5 can be used. When the sensor 11 which is the tension sensor provided in the sheave 3 is used, the existing tension sensor can be effectively used. The position of the sensor 11 may be in the vicinity of the sheave 3 or in the vicinity of the work object T (for example, the hook F). Further, the external force applied to the work object T may be measured by a force sensor other than the tension sensor.

The control unit 10 controls the movement of the work object T by, for example, performing balancer control. Balancer control gives the work object T a virtual inertia, viscosity and spring constant, thereby the characteristics of power assist with respect to the work object T (for example, how light the force can move the work object T). And how quickly the movement of the work object T stops when the force is stopped to be applied to the work object T) is changed.

The control unit 10 controls the movement of the work object T by, for example, impedance control. Impedance control refers to a position and force control method for setting a desired value of mechanical impedance (inertia, viscosity and spring constant) generated when an external force is applied to an object.

The control unit 10 measures the external force applied to the work object T by the sensor 11, calculates the behavior of the system including the virtual inertia, viscosity and spring constant when the external force is applied by the impedance model, and this The desired impedance characteristic is realized by moving the work object T with the calculated value of the calculation. In this embodiment, the virtual inertia, viscosity, and spring constant calculated by impedance control may be the same as or different from the physical parameters of the work object T.

As an example, the control unit 10 has a first calculation unit 12 that calculates the target position of the work object T, a second calculation unit 13 that calculates the unwinding length of each wire 5 for each motor 7, and a second calculation. It includes an output unit 14 that outputs a command value of the unwinding length of the wire 5 calculated by the unit 13 to each motor 7. The first calculation unit 12 calculates the virtual inertia, viscosity, and spring constant based on the force measured by the sensor 11 to calculate the target position of the work object T.

FIG. 4 shows a block diagram of an exemplary calculation of the sensor 11, the first calculation unit 12, the second calculation unit 13, and the output unit 14. In FIG. 4, τ _m is the measured tension of the wire 5, _Pre is the target output node position, _{ext and est} are the estimated operating forces, and L _ref is the target wire length. The sensor 11 measures, for example, the measurement wire tension τ _m .

In the present embodiment, the first calculation unit 12 calculates the force applied by the worker M to the work object T from the values of each sensor 11. At this time, the force (gravity) due to the own weight of the work object T is canceled by the following statics calculation. As a specific example, the first calculation unit 12 performs statics calculation, dead zone processing, and calculation by the impedance model using _{the measured wire tension τ m, and sets the target output node position Pre} as the target position of the work object T. calculate. For example, the statics calculation by the first calculation unit 12 is performed by the following equation (1).

式（１）において、−ｆ_ｗｉｒｅはワイヤ駆動力（ワイヤ張力の合力）、Ｇは出力節の重力を示している。例えば、第１算出部１２による不感帯処理は下記の式（２）によって行われる。

In equation (1), -f _wire indicates the wire driving force (the resultant force of the wire tension), and G indicates the gravity of the output node. For example, the dead zone processing by the first calculation unit 12 is performed by the following equation (2).

The first calculation unit 12 has impedance parameters (for example, virtual mass M, virtual viscosity coefficient C, and spring constant K of the virtual spring) given in advance from _{the estimated operating force force, est} applied by the operator to the work object T. ) Calculates the target position of the work object T as the target output node position _Pre. The first calculation unit 12 may calculate the target speed or the target acceleration of the work object T instead of the target position of the work object T. When it is desired to move the work object T quickly according to the force applied by the worker M, the virtual viscosity coefficient C and the virtual mass M are preferably as small values as possible. However, if the virtual viscosity coefficient C and the virtual mass M are too small values, vibration may occur. Therefore, it is preferable that the virtual viscosity coefficient C and the virtual mass M are as small as possible within a range that does not vibrate. The spring constant K of the virtual spring is preferably 0 when it is not necessary to return to the original place when the force applied by the operator is removed.

The second calculation unit 13 calculates _{the target wire length L ref} of each wire 5 as the unwinding length of each wire 5 from the calculated _{target output node position Pref by inverse kinematics calculation.} The second calculation unit 13 may calculate the unwinding speed or the unwinding acceleration of the wire 5 instead of the unwinding length of the wire 5. Of the four wires 5 that suspend the work object T at the current position, each of x1, x2, x3, and x4 in FIG. 5 has an unwinding length x1 of the first wire and unwinding of the second wire. The length x2, the unwinding length x3 of the third wire, and the unwinding length x4 of the fourth wire are shown. As shown in FIG. 5, the second calculation unit 13 has the unwinding length y1 of the first wire and the winding of the second wire among the four wires 5 suspending the work object T at the target position. The unwinding length y2, the unwinding length y3 of the third wire, and the unwinding length y4 of the fourth wire may be calculated respectively.

The output unit 14 outputs a command value of the unwinding length of each wire 5 (for example, each of the unwinding lengths y1, y2, y3, y4 described above) to each motor 7 which is a drive system. In this way, the output unit 14 outputs the command value of the unwinding length to each motor 7, and each wire 5 is unwound at the unwinding length based on the command value, so that the work object T is positioned at a desired position. It becomes possible to move to.

Next, the operation and effect of the parallel wire mechanism 1 according to the present embodiment will be described. As shown in FIGS. 1 and 3, in the parallel wire mechanism 1, the plurality of wires 5, the work object T connected to the plurality of wires 5, and the wires 5 provided on the plurality of wires 5 respectively. A plurality of winches 6 for unwinding and winding are provided. The work object T is moved by unwinding and winding each wire 5 of the motor 7 in each winch 6.

Therefore, the work object T can be moved by unwinding and winding each wire 5 in the area surrounded by the plurality of wires 5, so that the work object T can be easily moved. be able to. Further, since the entire inside of the three-dimensional space formed by the plurality of wires 5 can be set as the movable range of the work object T, the work object T can be moved over a wide range.

The parallel wire mechanism 1 only needs to include a plurality of wires 5 and a plurality of winches 6 having a motor 7, and can eliminate the need for heavy equipment such as a crane, a guide rail, or an arm. Installation and replacement of 1 can be easily performed. Therefore, by easily installing and replacing the parallel wire mechanism 1 at the construction site A in a wide area, the work object T can be easily moved in a wide area.

Since the external force applied to the work object T can be measured by the sensor 11 and the work object T can be moved based on the measured force, the worker M can intuitively apply the force to the work object T. The work object T can be moved to. Further, in the present embodiment, since the work object T can be moved without applying the load of the work object T to the floor surface of the construction site A, the load capacity is limited on the deck slab under construction. Even if it is, it can be used.

Next, the parallel wire mechanism 1 according to the modified example will be described with reference to FIGS. 6 and 7. In the following, description that overlaps with the contents of the above-described embodiment will be omitted as appropriate. The parallel wire mechanism 1 according to the modified example uses the potential method in order to regulate the movement of the work object T out of the movable range of the work object T and to avoid the obstacle W.

The potential method is one of the route derivation methods, and by using the potential method, a place where the work object T does not want to approach, such as an obstacle W or an area outside the movable range described above, and a target of the work object T. The force for pushing back the work object T can be changed according to the distance from the position. In the potential method, a potential function is defined at the target position and the position of the obstacle W, and the gradient value of the potential function is increased toward the obstacle W to suppress the approach to the obstacle W while suppressing the approach to the obstacle W as described above. Derivation of the movement route to the target position. In the potential method, the path of the work object T can be changed in real time.

For example, in the parallel wire mechanism 1 according to the modified example, the first calculation unit 12 calculates the virtual rigidity by using the potential method. As an example, the first calculation unit 12 calculates the spring constant K as the virtual rigidity by using the following equation (3) according to the position of the work object T (the value of x below).

As described above, in the equation (3), the spring constant K of the virtual spring may be 0 or a value other than 0 depending on the position of the work object T. In this way, by changing the spring constant K according to the position of the work object T, it is possible to generate a spring force with respect to the movement of the work object T. Therefore, it is possible to generate a spring force that pushes back the work object T from the obstacle W with respect to the work object T approaching the obstacle W.

As described above, in the parallel wire mechanism 1 according to the modified example, the first calculation unit 12 changes the spring constant K according to the location of the work object T. Therefore, by changing the spring constant K when the work object T approaches a place where it is not preferable to approach, it is possible to make it difficult for the work object T to approach the place.

Further, by changing the spring constant K, it is possible to generate a repulsive force that makes it difficult for the work object T to approach the preset movable limit region or the obstacle W or the like. As a result, even if the work object T tries to approach the movable limit area or the obstacle W due to an operation error or the like, the repulsive force can prevent the approach, so that the work safety at the construction site. You can improve your sex.

In the above-described modification, a distance sensor is mounted on the work object T, and the distance sensor measures the distance to the obstacle W in real time, and avoids the obstacle W according to the measurement result of the distance sensor. May be done. In this case, similarly to the above, the first calculation unit 12 changes the spring constant K according to the location of the work object T, so that contact with the obstacle W can be avoided.

Subsequently, the parallel wire mechanism 1 according to a further modification will be described with reference to FIG. The parallel wire mechanism 1 performs wide area load reduction tracking control. That is, in this modification, the movement of the work object V in which the force is applied to the floor C is controlled instead of the work object T which is the suspended load described above. The work object V may or may not have a self-propelling function.

For example, concrete is cast on the floor C, and the work object V is a concrete finishing robot. As an example, the weight of the work object V is 200 kg. In this modification, the binding points of the plurality of wires 5 are provided on the work object V, and the parallel wire mechanism 1 reduces the load applied to the floor C. The work object V can also freely move in the region formed by the plurality of wires 5 like the work object T described above.

In the parallel wire mechanism 1 according to this modification, the first calculation unit 12 does not cancel a part of the force (gravity) due to the weight of the work object V when performing the statics calculation, and the target position of the work object V is not canceled. Is calculated. As a specific example, when the weight of the work object V is 200 kg and the load on the floor C is reduced to 50 kg, 150 kg is canceled.

As described above, in the parallel wire mechanism 1 according to the present modification, the first calculation unit 12 calculates the target position of the work object V without canceling a part of the gravity of the work object V. Therefore, when the work object V is placed on the floor C (ground, floor surface, etc.), the first calculation unit 12 performs the calculation without canceling a part of the gravity of the work object V. ..

Therefore, since a part of the gravity of the work object V is not canceled, a part of the gravity of the work object V is given to the floor C in a situation where the work object V placed on the floor C is desired to be moved. The Rukoto. As a result, a desired load can be applied to the floor C, and the load can be reduced by a required amount. For example, when the work object V is a concrete finishing robot, the robot's own weight is not applied to the top (surface) of the concrete after casting while applying the load necessary for finishing. Can be done. As a result, a smooth finish can be performed without sinking the concrete top end (surface) before curing due to a concentrated load of 200 kg (the robot's own weight).

The embodiment and modification of the parallel wire mechanism 1 according to the present disclosure have been described above. However, the parallel wire mechanism according to the present disclosure is not limited to the above-described embodiment or modification, and is modified or applied to other objects without changing the gist described in each claim. It may be. That is, the configuration, function, shape, size, number, and arrangement mode of each part of the parallel wire mechanism can be appropriately changed without changing the gist of each claim.

For example, in the above-described embodiment, an example in which the work object T is suspended from the binding points P of the plurality of wires 5 has been described. However, the work object may be suspended at a place other than the binding point of the plurality of wires. That is, the work object need only be connected to a plurality of wires.

Further, in the above-described embodiment, an example of moving the work object T by using the parallel wire mechanism 1 at the construction site A provided with the pillar 2 and the sheave 3 has been described. However, the configuration and type of the construction site where the parallel wire mechanism according to the present disclosure is used can be changed as appropriate.

1 ... Parallel wire mechanism, 2 ... Pillar, 3 ... Sheave, 5 ... Wire, 6 ... Winch, 7 ... Motor, 10 ... Control unit, 11 ... Sensor, 12 ... 1st calculation unit, 13 ... Second calculation unit, 14 ... Output unit, A ... Construction site, B ... String, C ... Floor, F ... Hook, K ... Spring constant, M ... Worker, P ... Cohesion point, T, V ... Work object, W ... Obstacle.

Claims (3)

With multiple wires installed at the construction site,
A plurality of winches provided on each of the plurality of wires and having a motor for unwinding and winding each of the wires.
A work object connected to the plurality of wires and supported by the plurality of wires, and
A sensor that measures the force applied to the work object,
Based on the force measured by the sensor, at least one of virtual inertia, viscosity and spring constant is calculated to calculate at least one of the target position, target velocity and target acceleration of the work object. 1st calculation part and
At least one of the unwinding length, unwinding speed, and unwinding acceleration of each wire for the work object to move at at least one of the target position, the target speed, and the target acceleration of each winch. The second calculation unit that calculates for each motor,
An output unit that outputs at least one of the command values of the unwinding length, the unwinding speed, and the unwinding acceleration to the motor of each winch.
Parallel wire mechanism with. The first calculation unit changes the spring constant according to the location of the work object.
The parallel wire mechanism according to claim 1. The first calculation unit cancels the gravity of the work object and calculates one of the target position, the target speed, and the target acceleration.
The first calculation unit performs the calculation without canceling a part of the gravity of the work object.
The parallel wire mechanism according to claim 1 or 2.

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