JP2638415B2 - Positioning device for heavy objects by the cooperation of the lifting machine and the robot - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for positioning heavy objects by the cooperation of a lifting machine and a robot capable of transporting and accurately positioning heavy objects as in the construction industry.

[0002]

2. Description of the Related Art Conventionally, in the operation of moving a heavy object by using a lifting machine such as a crane and positioning it at a predetermined position, a crane operator and a slinger signal with hands, flags, whistles and the like. It was done by such manual cooperation. This is due to a structural problem that it is difficult for the crane to perform accurate positioning by itself because the crane performs positioning through a non-rigid body such as a wire.

On the other hand, a machine capable of performing accurate positioning, such as an industrial robot, has a limited carrying capacity, and it is impossible to move and position a heavy object.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an apparatus for positioning a heavy object by cooperating a lifting machine and a robot, which moves a heavy object exceeding the carrying capacity of the robot and performs accurate positioning. The purpose is.

[0005]

According to the positioning apparatus of the present invention for coordinating a heavy object with a lifting machine and a robot, the robot and a heavy object suspended by a holding part of a hand of the robot are suspended. A heavy machine, a robot control unit that controls the operation of the robot based on a signal from a force sensor provided at the tip of the hand, and a crane control unit that controls the operation of the lift machine based on a signal from the robot control unit. The robot controller receives a target value for moving the member as a target position for movement of the gripper, receives a maximum value of the payload, captures the tip position of the robot, and simultaneously receives a reaction force acting on the tip of the robot from the force sensor. Is detected, and it is determined whether the force of each component is greater than the maximum value.For the component direction exceeding the maximum value, the tip of the robot is moved in the direction in which the force is applied, and For the direction that does not exceed the target position, the robot has a function of moving the tip of the robot in the direction of the target position and determining whether the position of the member is within the allowable range of the target position, and the control unit of the crane moves the member. The target position to be received is received as the position of the member at the tip of the hook, the current position and posture of the tip of the robot is detected by the encoder, and the obtained target position is compared with the current position to control the member to approach the target position. Then, it has a function of determining whether or not the tip position and posture of the member are within an allowable range of the target position.

[0006]

In the positioning device for heavy objects in cooperation with the lifting machine and the robot configured as described above, the crane lifts the heavy objects and roughly positions the robot within the movable range of the robot to perform the positioning of the heavy objects. Accurate positioning is performed by robot handling. At this time, since the object is a heavy object, the force applied to the distal end of the hand of the robot is detected, and based on the force, the robot handles the heavy object while carrying the heavy object in cooperation with the robot.

[0007]

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, the apparatus of the present invention comprises a robot 1 and a crane 20 as a lifting machine. The robot 1 is, for example, a six-joint type, and is provided with six actuators A1 to A6 and encoders E1 to E6. A grip portion 3 is provided at the tip of the robot, a six-axis type force sensor S is provided adjacent to the grip portion 3, and a member M which is a heavy object is gripped by the grip portion 3. . Then, the actuators A1 to A6 and the encoders E1 to E
6 and the force sensor S are the robot controller 1 of the controller 10
1 respectively. This control device 11 includes:
The arithmetic device 12 and the communication device 13 are connected.

On the other hand, the crane 20 is provided with an actuator A7 for operating the hanging wire 21 on which the member M is hung, an encoder E7, an actuator A8 for operating the boom 22 of the crane 20, and an encoder E8. Then, the actuator A7 and the encoder E7,
The actuator A8 and the encoder E8 are the control unit 30
Respectively. A communication device 32 is connected to the control device 31, and the communication device 32 is connected to the other communication device 13.

Next, a two-dimensional plane will be described with reference to FIGS. 2 and 3 to simplify the principle of control. As shown in FIG. 2, the robot 1 includes actuators A1 to A1.
A3, a three-joint type in which only the encoders E1 to E3 operate, and the member M suspended by the actuator A7 and the actuator A8 of the crane 20 is moved to the position P1 (P1X, P1
It is assumed that the user moves from Y) to a position P2 (P2X, P2Y). Here, it is assumed that the mass of the member M is m, and the mass m is larger than the payload mmax of the robot 1.

Now, for example, P2Y> P1Y, P2X = P1
X, and at a certain time t, the position P2 (P2X, P2
The target coordinates are set so as to satisfy Y). However, actually, in the response C1 of the crane 20, the tip of the member M is located at the position P.
Assume that the position mY = P2Y + δYm in the response C2 of the robot 1 where CY (t) = P2Y−δYC. In this state, the entire weight of the member M is applied to the robot 1 and exceeds the payload mmax.

[0012] On the other hand, when the responses of the two 1 and 10 are opposite,
The lifting capacity of the crane 20 is overwhelmingly greater than the output of the robot 1, and the crane 20 moves the robot 1 to P1Y + δ.
It will be pulled up to the position of YC.

Therefore, the force sensor S detects the direction and magnitude of the force applied to the gripper 3 and controls the gripper 3 to move in the direction in which the force is applied. Do not apply force that exceeds. In addition, within the range of the load of the payload mmax,
The robot 1 performs position control. The robot 1 also serves as a position sensor, and transmits the current accurate position of the member M to the control unit 30 of the crane 20. Crane 2
0 performs position control based on the information.

FIG. 4 is a block diagram of the control units 10 and 30. The robot 1 and the crane 20
Is assumed to be known in the absolute coordinate system. Further, although both are described only for one axis, the same applies to the other axes. Here, it is assumed that the actuators A1 to A3 and A7, A8 can perform a torque command (the output torque is linear with respect to the command value). In the drawing, the symbol F is a signal from the force sensor S, Fmax is the maximum value of the load capacity, P is the position of the member M, Pref is the target position, ω is the speed, J is the moment of inertia, J ^{− 1} is a coordinate transformation, KP and Kf are gains, Kμ is a speed feedback gain, 1 / S is an integral element, and C is b = C> O.
a, when C <O, b = 0 and D is b = −a, but the description is omitted because it belongs to a known technique.

FIGS. 5 and 6 show the control flow of the robot 1 and the crane 20, respectively.

In FIG. 5, the control unit 10 of the robot 1
Receives the target value for moving the member M as the movement target position Pref of the gripper 3 (the target position Pref is a value in the absolute coordinate system and is equal to the value received by the control unit 30 of the crane 20), and is portable. The maximum value of the weight is received as Fmax (step S1), and the target position Pref in the absolute coordinate system is converted to the coordinate system of the robot 1. Next, the position P of the tip of the robot 1 is captured by the encoders E1 to E3, and at the same time, the reaction force acting on the tip of the robot 1 is detected from the force sensor S (step S2). The detected values are X, Y, and X in the coordinate system of the tip of the robot 1.
There are a total of six components in the Z direction and torque components around each axis. Next, it is determined whether or not the obtained forces in the six directions are larger than the maximum value Fmax of the payload of the robot 1 (step S3). Then, among the components of the force in the six directions,
For the component direction exceeding the maximum value Fmax, a command signal is output to the actuators A1 to A3 to move the tip of the robot 1 in the direction in which the force is applied and release the reaction force (step S4). In addition, among the components in the six directions, the direction not exceeding the maximum value Fmax is the target position Pref.
A command signal for moving the tip of the robot 1 in the direction is output (step S5). Next, the position P of the member M is
It is determined whether the target position Pref has reached the allowable range (step S6), and if NO, step S2 is performed.
And if YES, end the control.

In FIG. 6, the control unit 30 of the crane 20
Receives the target position Pref for moving the member M as the position of the member M at the tip of the hook (this value is a value in the absolute coordinate system and is equal to the value received by the control unit 10 of the robot 1) (step S10). . Next, the target position Pref in the absolute coordinate system is converted into the coordinate system of the crane 20, and at the same time, the current position and posture of the tip of the robot 1 are detected by the encoders E1 to E3, and the values of the coordinate system of the crane 20 (this value Is equal to the position of the member M) (step S11). Then, the obtained target position Pre
f is compared with the current position, and control is performed so that the member M approaches the target position Pref. In practice, the deviation between the target position Pref and the current position is multiplied by a gain (coefficient), converted to the coordinate system of the crane 20, and a command signal is output to the actuators A7 and A8 (step S12). Then
It is determined whether the tip position and the posture of the member M have reached the allowable range of the target position Pref (step S1).
3) If NO, return to step S11, and if YES, end control.

[0018]

As described above, according to the present invention, when the robot exceeds the maximum value of the load capacity, the robot moves in the direction of the component, so that the reaction force can be released, and the crane is accordingly loaded. Will be responsible. Therefore, a heavy object exceeding the carrying capacity of the robot can be handled. And accurate positioning can be performed by the robot. Therefore, according to the present invention, when handling heavy objects, the strength of the robot can be reduced and accurate positioning can be performed.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram showing one embodiment of the present invention.

FIG. 2 is a diagram illustrating the principle of control according to the present invention.

FIG. 3 is a view for explaining a position control response between the crane and the robot.

FIG. 4 is a block diagram of control.

FIG. 5 is a control flowchart of a robot control unit.

FIG. 6 is a control flowchart of a crane control unit.

[Explanation of symbols]

 A1 to A8 Actuator E1 to E8 Encoder M ... Member S ... Force sensor 1 ... Robot 2 ... Hand 3 ... Grasping unit 10 ... Control unit 11 ...・ Robot control device 12 ・ ・ ・ Calculation device 13, 32 ・ ・ ・ Communication device 20 ・ ・ ・ Crane 21 ・ ・ ・ Suspension wire 30 ・ ・ ・ Control unit 31 ・ ・ ・ Crane control device

Claims (1)

(57) [Claims] 1. A robot, a lifting machine for suspending a heavy object gripped by a gripper of a hand of the robot, and a robot controlling operation of the robot based on a signal from a force sensor provided at a tip of the hand. A control unit, and a crane control unit that controls the operation of the lifting machine based on a signal from the robot control unit. The robot control unit receives a target value for moving a member as a movement target position of the grip unit, and The maximum value of the payload is received, the position of the robot's tip is captured, and at the same time, the reaction force acting on the robot's tip is detected from the force sensor, and it is determined whether the force of each component is greater than the maximum value. Move the robot tip in the direction in which the force is applied for the component direction exceeding, and move the robot tip in the direction of the target position for the direction not exceeding the maximum value. The crane controller receives a target position for moving the member as the position of the member at the tip of the hook, and determines the current position and posture of the tip of the robot. The position is detected by the encoder and compared with the obtained target position and the current position to control the member to approach the target position and determine whether the tip position and posture of the member are within the allowable range of the target position. A positioning device for heavy objects by cooperation between a lifting machine and a robot, which has a function to perform the operation.