JPS61262817A - System for controlling subject moving device - Google Patents

Abstract

PURPOSE:To shift a subject by external force without detaching the subject, to improve the accuracy of a teaching action or to transport a heavy subject by taking a synchronization of a speed command and a power measurement value for a speed command. CONSTITUTION:When the power measurement value Fr being the output of a power sensor 3 is other than zero, the synchronization of the speed command Vc and the power measurement value Fr turns out the synchronized speed command Vc, and an external force adaptation control is executed. At this time, when the speed command Vc is set to zero, a synchronized speed command V'c becomes the power measurement value Fr to execute an external force control mode. Accordingly, when a hand HD touches a hand 5 to give external force, the synchronized speed command V'c=(-Fr) from the power sensor 3 drives a moving means MT in a direction where the external force comes to zero, and the hand 5 is moved. Then, when the external force is released, the synchronized command speed V'c disappears, and the hand 5 stops.

Description

[Detailed description of the invention] [Table of contents] Overview Industrial field of application Conventional technology Problems to be solved by the invention Means for solving the problems (Fig. 1) Working example (α) One example Explanation of the configuration (Figures 2 and 3) (b)
Explanation of the external force control mode of one embodiment (FIG. 4).

(Figures 5 and 6) (C) Description of command control mode of one embodiment (FIG. 7).

(Fig. 8, Fig. 9) (d) Explanation of another embodiment (Fig. 10) (e) Explanation of another embodiment Effects of the invention [Summary] Control means or speed control of a moving means for moving an object In an object moving device that moves an object by using a control means or an external force detection means for detecting a force applied to an object, the system is configured so that a composite speed command is obtained by combining a force command and a speed command, and the force command is combined. By providing an external force control mode that is given as a speed command, movement can be performed in accordance with external force.

[Industrial application field]

The present invention relates to a control method for an object moving device such as a robot to move an object according to an external force applied to the object such as a hand.

Object moving devices that move objects are widely used in various fields.

For example, in a robot, the hand is moved to a desired position, allowing the hand to perform various tasks.

In general, object moving devices such as robots perform movement control based on predetermined movement commands, and in recent years, various control methods have been proposed in response to demands for higher intelligence of robots.

[Conventional technology]

In such a control method, it is known that a robot is given a sense of force and moves by detecting an external force.

For example, in Patent Application Publication No. 56-85106 (Patent Application No. 54-161557), in order to teach the robot, a force detector is installed at the tip of the robot.
The direction of movement of the robot is calculated based on the signal generated from this force detector, and the drive device that drives each arm of the robot is driven based on the calculated command value, thereby making it easier for the operator to teach. Some proposals have been made to reduce the burden of labor.

Such a proposal is one in which movement is performed by external force, and is known as a direct teach method.

[Problem that the invention seeks to solve]

However, in such conventional proposals, a force detector is provided in place of the hand, and the operator moves by applying an external force while holding the force detector, so the hand is moved by the external force while the hand is attached. I can't do anything. For this reason, for example, when teaching, the hand is actually taught to move, but since the hand is removed, the teaching can only be done assuming the position of the hand, and there is a problem that accurate teaching cannot be performed. .

Furthermore, there is a problem in that it is impossible to use the robot as a transportation robot when the hand holds an article and moves the article by manual external force because the hand must be removed. Furthermore, since it is necessary to construct a force control system different from a normal movement control system, the control system becomes complicated, and there is also the problem that the price inevitably increases.

SUMMARY OF THE INVENTION An object of the present invention is to provide a control method for an object moving device that can move an object by an external force without removing the object (hand) or changing the movement control system.

[Means for solving problems]

FIG. 1 is a diagram explaining the principle of the present invention.

In FIG. 1 (g), 5 is an object (referred to as a hand), for example, a suction hand that suctions an article, and 3 is a force sensor (referred to as a hand).
MT is a moving means which is composed of a motor and is for moving the force sensor 3 and the hand 5; 8 is a control unit (
control means), which has a synthesis section 85 that synthesizes the speed command VC and the force measurement value Fγ of the force sensor 3, and controls the moving means MT with the synthesized speed command V'C' (-VC-Fγ). It is something to do.

Therefore, in the present invention, basically a speed control system is constructed in which the speed command is a combination of the speed command VC and the force measurement value Fr.

[Operation] In the present invention, since the control system is constructed as described above, the speed command VC is issued in the normal movement command control mode. In this case, if no external force is applied to the hand 5, and therefore the force measurement value Fr is zero, the speed command vC' becomes the composite speed command ■'C, and the speed of the moving means is controlled by the speed command VC. Also, if an external force is applied to the hand 5 and the force measurement value Fr, which is the output of the force sensor 3, is zero, the speed command V is
C and force measurement value F? 'Composition (difference) with ' or composite speed command V'
C, and external force adaptive control is executed.

Therefore, when the hand 5 touches some object while moving, it autonomously shifts to external force adaptive control, that is, the speed command VC decreases by 21 minutes of the force measurement value, decelerates, and controls according to the external restraining force. is executed.

On the other hand, if the speed command VC is set to zero, the composite speed command V'G
becomes the force measurement value Fγ, and the external force control mode can be executed.

Therefore, when the hand HDJ touches the hand 5 and applies an external force, the composite speed command V'C=(-F'
γ), the moving means MT is driven in the direction in which the external force becomes zero, and the node 5 moves.

Therefore, as shown in FIG. 1 (13), the hand 5 at position Po
When you hold it in your hand HD and pull it in the direction of the arrow to apply an external force, the force measurement value Fγ as shown in FIG. That is, the moving means MT moves the hand 5 in the direction of the arrow to which the external force is applied.When the hand HD is stopped at the position P1 and the external force is released, the force measurement value Fγ also falls as shown in FIG. ■'C also falls and the hand 5 stops.Therefore, the object can be moved by external force without changing the speed control system.

〔Example〕

(α) Description of configuration of one embodiment FIG. 2 is a configuration diagram of one embodiment of the present invention, taking an orthogonal robot as an example.

In the figure, the same components as those shown in FIG. , 10h to transport and position the transport pallets 11α, 11b in the X-axis direction, 2 is a gate-type robot, and a pair of support bases 20.21 provided on both sides of the X-axis modules lα, 1h, and The two-axis block 22 moves in the Z-axis direction, the two-axis movable part (arm) 23 moves in the Z-axis direction, and the two-axis block 22 is sent, and the hole screw 24
A Y-axis motor 24 rotates the arm 1Z and drives it in the Y-axis direction along guides 25α and 25b, and a Z motor 24 that is provided on the two-axis block 22 and drives the two-axis arm 23 in the Z-axis direction via a ball screw feeding mechanism (not shown). It has a shaft motor 26. 3 is the aforementioned force sensor, which consists of a leaf spring mechanism and a strain gauge, and converts the displacement of the leaf spring due to external force into an electrical signal using the strain gauge, and has four degrees of freedom in the X, Y, Z, and r axes. 4 is a γ-axis motor,
It is supported by the Z-axis arm 23 and rotates the sensor 3 and hand 5 around the r-axis. 5 is a vacuum suction hand, and as shown in FIG. 5, which will be described later, a suction surface is provided at the tip of the cylindrical body. 6 is a jig, and a pallet 11α has an intake tube connected to an intake pump.
7 is a base which is mounted on the pallet 11b and to which the disk 9 is attached.

Reference numeral 80 is an operation panel, which is operated by an operator to input commands and data; 81 is a memory, which stores teaching data, etc.; and 82 is a processor (hereinafter referred to as Cp).
(referred to as U), which is composed of a microprocessor, etc.
83 is a servo control unit that reads the contents of the memory 81 and gives commands to each unit during playback, and controls the X-axis module 14, the X-axis motors 10IZ, IOA, and Y of IA.
In order to control the position and speed of the axis motor 24, z-axis motor 26, and γ-axis motor 4, the command position CX2 from the CpU 82
, Cx,, C'Y, CZ, Cr, the current position PX2 from the hand position detection circuit described later,
PXI, PY, PZ, P γ Cuffy 1' is hacked, and furthermore, the command speed ■CX~v(r
are input, and these are used to control fjl,
84 is a power amplifier that amplifies the input and outputs X, Y,
Z, γ-axis motor 10 (L, 10b.

24.26. 85 is the above-mentioned synthesizing section, and as will be described later with reference to FIG.
86 is a teaching box that takes the difference from Give Z-axis key 86
87 is a force control unit which receives the detection output F''X-Fγ1 of the force sensor 3 as will be described later in FIG. 88 is a hand position detection unit that converts into digital values FX~Fγ, sets a dead zone, and outputs a control output PFX−PFγ, and motors 1071, 10h, 2 of each axis
4, 26. The current position of each axis PX1, PX2, P is determined from the output of the rotary encoder.
89 is a bus that calculates Y, PZ, and PF and obtains the current position of the hand 5, and a CPU 82 and a memory 81. Operation panel 80. Teaching box 86. →No-vo control section 831 synthesis section 85. The force control unit 87 and hand position detection circuit 88 are connected to exchange data and commands.

FIG. 3 shows the force control section 879 and the combining section 85. Servo control section 83
and a crushing circuit of the power amplifier 84.

In the figure, the ones shown in Figure 2 are shown with the same symbols, and 800 to 803 are composite circuits for each axis.
Force control command PFX-PFγ from force control unit 87 and CPU
One that outputs the difference between the speed command VX~■z from 82,
Reference numerals 804 to 807 are dead band parts, which are set by the dead band widths WX to Wγ from the CPU 82 and provide a dead band to the force measurement value FX-Fr. 808 is a switch that allows input of the force measurement value FX-Fr; It is prohibited,
809 is an analog/digital converter (
An analog force measurement value FX from the force sensor 3.

83α to 83d are servo circuits that convert F'Y, F'Z, and Fγ into digital values and output them to the switch 808, and they convert the current position from the position detector 88 and command positions CX, CY, and CZ. , Cr(!:(D) which performs position control based on the difference and speed control based on the difference between the commanded speed v'X~■'γ and the actual speed, 84α~84d are power amplifiers, A drive current is supplied to the motor of each axis based on the output of the circuits 83α to 83d.

Therefore, when the switch unit 808 is turned off by the CPU 82, the output of the force sensor 3 (i.e. A/l) converter 8
09 output) is dead zone 8o4゜805.806,80
7 is not input, the CPU feedback is turned off, and the CpU
Commanded positions CX', CY, CZ, Cr and commanded velocities vx, vy from 82.

vz', vY or just the servo circuits 83α to 83 for each axis
d, and the position and speed are controlled.

On the other hand, when the switch section 808 is turned on by the CPU 82, the feedback is turned on, and the output of the force sensor 3 is transmitted through the dead zone sections 804 to 807 as control outputs PFX, P.
FY, PFZ, PF r and synthesized @800~8
03 and command speed ■X.

Composite output of vY, ■z, vr, = V'X, V'Y
, V'Z.

v'r is given to the servo circuits 83α to 83d as a speed command.

It should be noted that there are two X-axes, an Xl-axis and an X2-axis, or there are actually two X-axes, although this is shown by one X-axis servo circuit 83α and one amplifier 84α.

(h) Description of external force control (teaching) mode according to the configuration of one embodiment.

FIG. 4 is a process flow diagram of the teaching mode as an example of the external force control mode, FIG. 5 is an explanatory diagram of its operation, and FIG. 6 is a diagram of the internal configuration of the memory.

The process of suctioning and taking out the disk 9 set in the jig 6 on the pants l-11iZ shown in FIG. will be explained below using as an example.

@The operator presses key 8 on the teaching pendant 86.
6α to notify the CPU 82 of the teaching mode via the bus 89. The CpU 82 determines that direct teaching has been instructed, and transmits the force control unit 8 via the bus 89.
7, turn on the switch 808, and turn on the cafe feedback L.
do. Further, the CPU 82 communicates with the force control section 87 via the bus 89.
Dead band widths wx and wy are provided in each of the dead band portions 804 to 807.
, wz.

Set Wγ.

(2) The operator holds the hand 5 in his hand and pulls (or pushes) the hand 5 in the direction of the target position overhead (point B). When an external force is manually applied to the hand 5, the force sensor 3 detects the external force in the direction in which the external force is applied. For example, in the case of FIG. 5, an external force in the +Y direction is applied, and the force sensor 3 outputs a Y-axis force measurement value FY. This force measurement value FY is A/l
) After being converted into a digital value by a converter 809, it is input to a dead band section 805.

Each of the dead band sections 804 to 807 feeds back a signal through a nonlinear element to the force measurement value FX-Fγ, and when the absolute value of the input force i is smaller than the dead band setting value W, the output is set to zero. . On the other hand, when the absolute value of the input is larger than the dead band width setting value W, when the input is a positive value, (input -
(dead band width setting value) is output, and when the input is a negative value, (input child dead band width setting value) is output.

If the hand 5 is floating in the air due to the presence of these dead zones 805 to 807, and there is an offset variation in the force measurement value of the force sensor 3 when you want to keep it in place, the position of the hand 5 will drift. Otherwise, it becomes insensitive to offset fluctuations smaller than the dead band width, and no drift phenomenon occurs.

Further, when the hand 5 is guided by the operator, an appropriate resistance force (corresponding to the width of the dead zone) can be generated as a response to the operator.

Therefore, the force measurement value FY is subjected to the above-described dead band processing in the dead band section 805, and is inputted to the synthesis circuit 801 as the force command PFY. Here, the position commands Cx, cy from the CPU 82 are
, cz, cy and speed commands VX, VY, VZ, and Vr are zero, so the composite speed command V'Y is PFY itself, and is input as a speed command to the Y-axis servo circuit 83h, and is input to the Y-axis via the power amplifier 84b. Drive the motor 24. Therefore, the hand 5 moves toward point B in the direction in which the external force is applied, following the movement of the hand holding the hand 5. When hand 5 reaches point B, the operator moves the hand from hand 5 to 1ij1.
r. At this time as well, the drift phenomenon is prevented by the dead band parts 804 to 807, and the hand 5 stops at point B.

@ Next, the operator holds the hand 5 and lowers the hand toward the zero point. Similarly to the step, the force sensor 3 outputs the force measurement value FZ in the two axial directions of the external force and application direction, and a force command PFZ is generated via the A/D converter 809, switch 808 and dead band section 806, and similarly The composite speed command VZ (--PFZ) is input to the Z-axis servo circuit 83.0, and is sent to the two-axis motor 26 via the power amplifiers 84 and c.
1 drive.

Therefore, the hunt 45 moves toward the zero point in the direction in which the external force is applied, following the movement of the hand holding the hunt 95. Furthermore, the operator fits the hand 5 into the jig 6. At this time, if there is a deviation in the X and Y directions, that is, if point B does not match the center of the jig 6, fitting will not be possible, so the operator applies external force to the hunt 95 in the X or Y direction. The force sensor 3 generates Y-axis or Y-axis force measurement values FX and FY,
Similarly, the X-axis motor 10α or the Y-axis motor 24 is driven to move the hand 5 to follow the movement of the hand, and the fitting is performed. As a result, the hand 5 is accurately positioned at the center of the jig 6 (i.e., the disk 9), and the X2 axis.

The Y-axis element is determined.

■ The operator releases the hand 5 and presses the 2-axis up key 86A of the teaching box 86.

As a result, the CPU 82 issues a Z-axis speed command ■z, and sends VZ to the synthesis circuit 802 via the bus 89 while the key 86h is being pressed.
The composite speed command VZ=■Z is given to the Z-axis motor circuit 83C, and the Z-axis motor 2 is supplied via the power amplifier 84c.
6 to raise the hunt 95 in the Z-axis direction. Even when Hunt 95 comes out of the jig 6, the dead zone 8 described above
04 to 807, the positions of the X2 axis and the Y axis are maintained. In other words, since the Coulomb-superior characteristic is artificially created by applying a nonlinear calculation called a dead zone, it will not move unless an external force of a certain level or more is applied. When the key 86b is stopped being pressed at the desired position where the hunt 95 has completely come out from the jig 6, the CPU 82 sets the Z-axis speed command VZ to zero, so the hunt 95 stops rising.

■ Next, when the operator presses the end key 860 of the teaching box 86, the CPU 82 starts the teaching mode 9.
After completing the operation, the command 9 received from the keyboard 9 of the 6th channel 8o will be in the state. The oiler issues a POINT command (POINT) from this keyboard as command 9.
DISK).

■ This command causes the CPU 82 to detect the position detector 88 (
1) Each axis (7) value X (Xl, X2), Y, Z, T is read through the nozzle 89 and stored in the memory 81 as teaching data.

The memory 81 includes a work table 81α as shown in FIG.
A coordinate table 816 is included in the work table 81α, and macro commands are written in advance in order of work sequence. For example, the sequence ``'''ioo'' (7,)lPI
CK DISKJ moves to Al point (described later), descends at the specified speed, and adsorbs disk (DISK) 9 (PICK).
L,, is the command 9 to return to a certain point, and the sequence ° "100""PLA, cE 5PINDLEJ"
moves to a certain point, descends at a specified speed, and spins what it attracts.

This is a command to return to a certain point. Such a macro instruction "PIα" rP
Providing LA CEJ etc. will make it easier to give work instructions. On the other hand, the coordinate table 81b contains l'-DISKJ, [5PI-NDL, which is the object of the macro instruction mentioned above.
The position coordinates of the above-mentioned point on EJ are stored, and the positions of each axis read by the above-mentioned CPU 82 are stored.

Therefore, at the coordinates Chinor 81A, IPOI N'l'D
When ISKJ is specified in step ■, the position of each axis is stored in the [DISKJ column, and this position indicates the coordinates directly above the target article (disc 9) (for example, point G in FIG. 5). become.

Hereinafter, the teaching for fitting the disc 9 to the spindle 912 will be performed in the same manner.

Here, even if a plurality of discs 9 are stacked on the jig 6, "D
With one coordinate value in the IsKJ column, extraction is possible as described in the following (cl).In other words, there is no need to teach the depth direction of each disk 9, and extraction is performed smoothly by external force adaptive control. .

(El Description of the command control motor 9 based on the configuration of one embodiment.

FIG. 7 shows the disk suction operation (PI) as the movement command motor 9.
CK DISK), FIG. 8 is an explanatory diagram of the movement command mode, and FIG. 9 is an explanatory diagram of the operation of the movement command mode r.

(2) When the 5TART command 9 is input from the operation panel 80, an operation start command is given to the CPU 82 via the bus 89.

As a result, the CPU 82 decodes the command statement in the work table 81c of the memory 81, determines that "PICKDISKJ means to pick up by suction (PICK)", and starts the picking process.

Next, the CPU 82 reads the "DIsKJ" column of the coordinate table 81a of the memory 81, and selects the above-mentioned point G (X21Y, Z
) and obtain the position commands CX2, CY,
cz through the /s path 89 to the servo control section 83 and x, y, z speed commands VX2. VY,
I will give you VZ.

This causes the servo control unit 83 to control /-? Drive currents sx1, sy, sz are supplied to the X-axis motor 10α, Y-axis motor 24. Z-axis motor 26'
supplied to

Therefore, the X-axis motor 1 of the Y-axis (X2-axis) module 1a
0α, Y-axis motor 24. The Z-axis motor 26 is driven,
The vacuum suction hunt 95 is positioned at a designated point G (FIG. 5) on the disc 9 of the jig 6 of the Flet 11α on the X-axis module 1α.

■ Next, the CPU 82 checks whether or not the hand has reached a predetermined position from the current position PX2, PY, PZ of each axis of the hunt 9 position detection circuit 88, and determines whether or not the hand has reached a predetermined position after stopping at the predetermined position. After the elapse of time (approximately 0.5 seconds), it is assumed that the force sensor 3 has stopped vibrating, and the feed 9 and 2 switches are turned on. That is, the force control section 87PFZ can be input to the synthesis section 85.

(2) The CPU 82 provides the speed command value vZ to the synthesis section 85 via the path 89. As described above, since the force command PF'Z is 0 before contact with the disk 9, it is outputted as a command speed to the servo circuit 83c to control the speed of the Z-axis motor 26. Therefore, the suction hand 5 moves toward the disk 9 at the commanded speed v1.
to descend.

■ On the other hand, the CPU 82 monitors the force measurement value FZ of the A/D converter 809 of the force control unit 87 via the bus 89, and
When becomes a predetermined value M, it is determined that the suction hand 5 has contacted the disk 9.

At the same time, the system autonomously shifts to external force adaptive control as described above. This will be explained with reference to FIG.

When the hand 5 is approaching the disk 9, the force measurement value F of the force sensor 3
Since Z is zero, VZ=VZ, and the Z-axis motor 26 is connected to the nozzle amplifier 841 by the servo circuit 83c.
? The hand 5 is lowered by speed control via the lower end.

On the other hand, when the hand 5 contacts the disk 9 at position PI (time 11), the force sensor 3 or the plate spring flexes, and the strain gauge 30 that detects this flexure generates a force measurement value FZ. Or, the pressing corresponding to the dead zone width WZ continues to move at the speed given by the command ■Z until it reaches the force (force measurement value FZ), and at time t2, FZ>WZ becomes, so that the force command PFZ or Occur. Therefore, the synthesis circuit 802
The output v'z is (VZ - PFZ), and the resultant speed command v'z is the force command PFZ subtracted from the speed command vZ, which apparently reduces the speed command value and reduces the force measurement value F.
Z rises and hand 5 decelerates further.

In the final equilibrium state, the two-axis motor 26 stops at position PO at time 1o, and the actual speed value becomes zero.

At this time, the input command ■Z is equal to the force command PFZ, and the force command P
Since FZ is △ pressed against the object 9 by deformation of the force sensor, it becomes a force Fυ, so the input command ■Z acts as a force command. Therefore, the magnitude of the input command z controls the pressing force.

The pressing force at this time will be the force corresponding to the force command value and dead zone width W by the input command For pushing, the force can be controlled independently.

Input command ■Z is the speed command value at the time of approach. Pushing also serves as both the force command value at the time of force generation, so the relative magnitude of the output level of the speed measurement value vZ and the force meter side value FZ In this case, there is a possibility that one input (Z) may not be able to satisfy both the optimal movement speed and the optimal pressing force at the same time.

For this reason, an input is provided to make the feedback amount of the force measurement value FZ variable, that is, the speed command z and the dead band width Wz are set independently according to the dead band width Wz, and the optimum speed command value and force command are set independently. and the value can be obtained with one input command. In addition, since the feedback gain of the force measurement value FZ can be fixed, the pressing force can be varied over a wide range while keeping the loop gain as a closed loop control system constant (that is, while guaranteeing stability as a control system). , and when the hand 5 is floating in the air (that is, when the hand 5 is not pushing another object), when you want to set the input to zero and keep it in place, there is an offset change in the force measurement value of the force sensor 3. If this occurs, the position of the hand 5 may drift, but in this embodiment, it becomes insensitive to offset fluctuations smaller than the insensitivity width, and the drift phenomenon disappears.

) Therefore, if the rotational speed of the motor 26 is continuously reduced while the shock at the time of contact is absorbed by the deflection (deformation) of the force sensor 3, appropriate pressing will result in no force being applied when the speed reaches zero. It is possible to create an ideal form in which it occurs.

In this way, the three processes of approaching, contacting, and pressing are performed continuously, smoothly, and autonomously.

In other words, when a robot works to grind an object, the robot's hand approaches the object, makes contact with it, and then presses the object with a certain force to grip it. In this case, the hand holding the object approaches the object, makes contact with the object, and then presses the gripped object against the object with a constant force to fit and attach the object.

In the present invention, the above-mentioned approach and contact of the hand, which is a moving body,
The three processes of constant force generation can be controlled continuously and autonomously.

In other words, the rotational speed of the motor decreases continuously before and after contact, so the impact at the time of contact is kept small, and the linear force output value of the force sensor 3 is used to change the timing from speed control mode to force control mode. It is possible to switch well and smoothly.Also, during force control, the feedback of the speed measurement value (actual speed) is generated as a so-called damping ring of tP&d feedback, so as a control system, Furthermore, as shown in FIG. 5, when a stack of magnetic disks 9 and spacers 90 is picked up one after another and transferred to another location, the hand 5 can move the magnetic disks 9 or spacers 90. Even if the depth when picking changes, the desired hand operator speed and desired force can always and automatically be obtained, making it unnecessary to teach the distance in the depth direction. This will reduce the burden on humans who teach robots how to work, and will make robots one step more intelligent.

Also, at this time, if there is a positional deviation in the X-axis direction as shown in FIG. 9, and the hand 5 comes into contact with the jig 6 while approaching the disc 9, and the fitting is not performed smoothly, Due to the contact with the jig 6, the force sensor 3 outputs the X-axis force measurement value FX as shown in Fig. 8 (
C), and when F'X>WX, the force command PFX is output, and the composite speed command V'X (=-PFX) is generated via the composite circuit SOO, and the X-axis servo circuit 83α and the power X-axis motor 10 via amplifier 84α
α is driven, in this case the pallet lid, i.e. the jig 6
When the hand 5 and the jig 6 move in the direction of the arrow X in the figure, the relative positional error between the hand 5 and the jig 6 in the X-axis direction is corrected. This is the same for Y@, and as long as the maximum drag is smaller than the dead zone width, it will follow the jig 6, so the relative position error between the hand 5 and the jig 6 will be absorbed by the deflection of the force sensor 3. On the other hand, when the dead band width is exceeded, the relative position error is corrected by driving the motor as described above, and the center of the jig 6 (the center of the disk 9) and the center of the hand 5 are automatically aligned.
Inserted or executed. Changing the width of this dead zone means changing the apparent electrical force.

■Furthermore, the CPU 82 monitors the output of a pressure sensor (not shown) that detects the negative pressure in the intake tube via the bus 89,
It is detected whether the suction hand 5 or the disk 9 is suctioned.

(2) When the CPU 82 determines that the suction hand 5 or the disc 9 has landed, it sets the speed command value (2) to zero, and then turns off the above-mentioned switch 808 to turn off the feedback.

Furthermore, in order to raise the suction hand 5, the CPU 82 reads the coordinates in the rDIsKJ column of the coordinate table 811:1 described above, and returns it to point G in the same manner as in step (2). As a result, only the disk 9 can be taken out. Next, in order to fit this polished disk 9 onto the spindle 12, the following sequence r PLAC of the work table 81α is performed in the same manner as described above.
E 5PINDLE J is read out, thereby reading out the coordinates in the rSPINDLEJ column of the coordinate table 81b, and the base 7 is lowered in two directions in the same manner as in steps ■, ■, and ■, and the base 7 is approached, contacted, and pressed, and adsorption is performed. After releasing it, the disk 9 is attached to the base 7.

In this way, in the movement command mode, the approach to the object,
The contact and pressing are executed autonomously, that is, the external force adaptive control is autonomously executed, and even if there is a positional deviation from the position according to the teaching data (for example, even if the position of the jig 6 is slightly shifted), Is it possible to fix this?

(d) Description of another embodiment FIG. 10 is an explanatory diagram of processing of the CPU 82. In this example, the functions of the synthesis section 85 and the force control section 87 are performed by the execution of a program by the CPU 82.

In the main routine, the CPU 82 analyzes commands in the teaching data, executes them to create position commands, speed commands, and force commands for each axis, and sends them to the servo control unit 8 via the bus 89.
3, and the current position Pγ~P from the position detection unit 88
The position of each axis and the force measurement value Fγ of the force sensor 3 are determined by X2.
~Monitor FX via D/A converter.

In the feedback off mode, the switch is connected as shown by the dotted arrow line, and the command position and command speed are directly given to the servo control unit 83, and each axis servo circuit 83α to
Each axis is positioned at a commanded position via 83d. On the other hand, when the engine feedback mode is on, the switch is connected as indicated by the dotted arrow line, and an interrupt processing routine for engine feedback control is executed at a predetermined period. That is, force sensor 3
Force measurement 4IIJiFγ ~ FX is offset corrected, and dead band processing is performed to adjust the feedback gain α to #(ke control output PF
X-PFZ is Samurai, and what is subtracted from the commanded speed or commanded force is the commanded speed V'γ~V'X2, and bus 89
It is given to the servo control unit 83 via.

In this case, the feedback gain α controls the slope of the deceleration shown in FIG. 8(A), and similarly to the dead zone described above, the command speed and pressing force can be controlled by one input.

Therefore, the force command PF becomes =α·(FW).

(e) Description of another embodiment If the servo circuit 83 described above is composed of a function generating section and a closed loop control section proposed by the present inventors, a more stable servo system can be realized. This servo circuit is described, for example, in the magazine [Nikkei Electronics] 98]
, No. 9.28'' (published by Nikkei McGraw-Hill), etc., so it will not be described in detail.

Furthermore, although the robot has been described as an orthogonal type robot with an X-axis divided, the present invention may also be applied to other orthogonal type robots, or even multi-joint type robots.

Further, as an example of the operation, the assembly of a magnetic disk device has been explained as an example, but the operation is not limited to this, and other operations may be used. The hand 5 may be conveyed to a desired position by hand, or it may be moved to another position when the hand 5 is in a position that is inconvenient for work.

Although the present invention has been described above using examples, the present invention can be modified in various ways according to the gist of the present invention, and these are not excluded from the present invention.

〔Effect of the invention〕

As explained above, according to the present invention, it is possible to move an object by external force without removing the object, for example, the accuracy of teaching operation is improved, and it is also possible to transport heavy objects. . In addition, since it can be realized without changing the movement control system, it not only has the effect that the system is stable, but also has the effect that it can be realized without complicating the system.
High prices can also be prevented. Moreover, since it is realized by a system capable of autonomous state (external force) adaptive control, it also has the effect of making it possible to move objects by external force using this function, making it extremely convenient for external force control, especially for robots. By using it, it will greatly contribute to making robots more intelligent.

[Brief explanation of drawings]

Fig. 1 is a diagram explaining the principle of the present invention, Fig. 2 is a configuration diagram of an embodiment of the present invention, Fig. 3 is a circuit diagram of the main part of the configuration shown in Fig. 2, and Fig. 4 is a processing in external force control mode according to the present invention. Flowchart, FIG. 5 is an explanatory diagram of the operation of the configuration shown in FIG. 2, FIG. 6 is an internal configuration diagram of the memory configured in FIG. 2, FIG. The figure is an explanatory diagram of the movement command mode in Figure 7, and Figure 9 is an explanatory diagram of the movement command mode in Figure 7.
FIG. 10 is an explanatory diagram of another embodiment of the present invention. In the figure, 3... force detection means, 5... object (hand), 8... control means, MT... moving means.

Claims (3)

[Claims] (1) A moving means for moving an object, a force detecting means for detecting an external force applied to the object, a speed command and a force command corresponding to the detection output of the force detecting means, and a composite speed command that is set as a composite speed command for the moving means and a control means for controlling the movement of the object, and the control means has an external force control mode for controlling the movement of the moving means using the force command as the composite speed command, and the control means has an external force control mode for controlling the movement of the moving means using the force command as the composite speed command, A control method for an object moving device, characterized in that the object is moved in a follow-up manner. (2) A control system for an object moving device according to claim (1), wherein the external force is applied by manually operating the object. (3) A control system for an object moving device according to claim (2), characterized in that the control means obtains teaching data from a position caused by the movement of the moving means.