JPH0566610B2 - - Google Patents

Description

[Detailed description of the invention]

[Table of Contents] Overview Industrial Application Fields Conventional Technology Problems to be Solved by the Invention Means for Solving the Problems (Fig. 1) Working Example (a) Explanation of the configuration of one example (Fig. (Fig. 2, Fig. 3) (b) Explanation of the teaching box and teaching data (Fig. 4, Fig. 5) (c) Explanation of the teaching mode (Fig. 6, Fig. 7, Fig. 8)
(Fig. 9) (d) Explanation of playback mode (Fig. 10) (e) Explanation of another embodiment (Fig. 11) (f) Explanation of another embodiment Effect of the invention [Summary] Object movement In a teaching control method for teaching an operation to a device, a control means for controlling the movement of an object moving means as a composite movement command by combining a movement command and a force command from a force detection means, and a control means for controlling the movement of an object moving means, and instructing movement for teaching. By providing an operating means having a means for issuing a first instruction to instruct to move and a means for issuing a second instruction for not instructing → movement, and creating a corresponding movement command in response to a movement instruction from the operating means. This makes it possible to easily perform both remote teaching and direct teaching. [Industrial Application Field] The present invention relates to a teaching control method for an object moving device such as a robot, which teaches the operation of an object moving device, and particularly to a teaching control method for an object moving device that allows both remote teaching and direct teaching. Regarding. Object moving devices that move objects are widely used, and a typical example is a robot, which positions a hand as an object at a desired position and thereby performs a desired task. It is said that In this type of robot, operation commands and position/attitude data necessary for work such as the position the hand should pass, the posture of the hand, and the movement are stored in the robot's storage device (memory) by teaching. On the other hand, during playback, movement commands and position/attitude data are sequentially read out from the storage device, and the arm and hand are controlled to reproduce the movement as taught. This type of robot control method is called a teaching playback method. [Prior Art] The following two methods are conventionally known as methods for teaching the position of the hand, etc. One type is called direct teach, in which an operator grasps the robot's hand and directly teaches its movements. The other method is called remote teaching, in which an operator operates a control panel called a teaching pendant, operates the robot, and teaches by remote control. This direct teach method has the advantage that it is intuitive for humans because it allows the hand to be held and guided freely, and teaching can be done easily and quickly.
As shown in Publication No. 85106, a force detector is provided 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 direction of the robot's movement is calculated based on the calculated command value. A device has been proposed in which the labor burden on the operator who performs teaching is reduced by driving a driving device that drives each arm. On the other hand, the remote teach method allows for safe teaching because there is no direct contact with the robot, and it is also a direct teach method that allows teaching even to large robots that cannot be reached by human hands, or small robots that cannot be reached by human hands. For example, as shown in Patent Application Publication No. 116806/1980, a force detector is provided at the tip of the robot, and the signal generated from this force detector is fed back into the servo loop. A method has been proposed in which teaching is performed while correcting the positional deviation of the hand relative to the target object in response to operation instructions from the operation panel. [Problem to be solved by the invention] However, in recent years, there has been a trend to have robots perform complex and advanced tasks, and with conventional configurations, only one of the direct teach method and the remote teach method can be used. There has been a problem in that teaching suitable for the work cannot be achieved, and teaching of such advanced work is very troublesome. In addition, in accordance with recent demands for mass production, it is desirable that the robot control system itself be capable of both direct teach and remote teach;
Another problem has arisen in that it is necessary to design and prepare two control system devices, and it is necessary to select one according to the user's requirements and the type of robot. SUMMARY OF THE INVENTION An object of the present invention is to provide a teaching control method for an object moving device that can perform both direct teaching and remote teaching with one control system. [Means for Solving the Problems] FIG. 1 is a diagram illustrating the principle of the present invention. In FIG. 1A, 5 is an object (referred to as a hand), for example, a suction hand that suctions an article, and 3
is a force sensor (force detection means), which detects external force applied to an object; 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), and has a synthesis section 85 that synthesizes the movement command Vc and the force measurement value Fγ of the force sensor 3, and the synthesized movement command
The moving means MT is controlled by V′c (=Vc−Fγ), and 86 is an operating means that is operated for teaching and issues a movement instruction RT for teaching. Therefore, in the present invention, basically a control system is set up in which the movement command is a combination of the movement command Vc and the force measurement value Fγ. Although not shown, the teaching means 86 includes the following:
A means for issuing a second instruction for not instructing movement, that is, a means for emitting a movement instruction value DT of zero (for example, a switch, etc.), and a means for issuing a first instruction for instructing movement, that is, a means for issuing a movement instruction value DT of zero. Means (similarly, a switch or the like) for issuing a movement (eg speed) instruction value RT is provided. That is, the present invention provides a moving means for moving an object;
a force detection means for detecting a force applied to the object; a first instruction means for instructing movement for indirect teaching;
and a second instruction means for instructing direct teaching, in a teaching control system for an object moving device capable of direct teaching by the output of the force detecting means and indirect teaching by a movement command, wherein the force detection A control unit is provided that converts the detection output of the means into a force command via a non-linear element that provides a dead zone, and controls the movement of the moving means with a composite movement command that combines the movement command and the force command, the control unit , in response to the operation of the first instruction means, creates a movement command corresponding to the movement instruction for teaching, performs indirect teaching accompanied by external force adaptive control based on the composite movement command, and at the same time, the second instruction means According to the operation of the object, direct teaching is performed using the force command generated by manual operation of the object. Further, an embodiment of the present invention is characterized in that the control section creates a speed command as the movement command. [Operation] In the present invention, since the control system is set up as described above, when a movement instruction RT is given from the operation means 86, a corresponding speed instruction Vc is created and the speed instruction shown in FIG.
Move hand 5 from point P ₀ according to the movement instruction as shown in
Move to P ₁ and enable remote teach.
At this time, if no external force is applied to the hand 5 and the force measurement value Fγ is zero, the speed command Vc becomes the composite speed command V'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 Fγ, which is the output of the force sensor 3, is not zero, the combination (difference) of the speed command Vc and the force measurement value Fγ becomes the composite speed command V'c, and the external force is Adaptive control is performed. 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 the force measurement value Fγ, decelerates, and responds to the external restraining force. Control is executed. On the other hand, if the movement instruction is not output from the operating means 86, the speed command Vc is zero, so the composite speed command V'c becomes the force measurement value Fγ, and the control mode using external force can be executed. Therefore, when the hand HD touches the hand 5 and applies an external force, the moving means MT is driven in the direction in which the external force becomes zero according to the composite speed command V′c=(−Fγ) from the force sensor 3. Then, hand 5 moves. For example, when the hand 5 at position P ₀ is held in the hand HD as shown in FIG. 1B and an external force is applied by pulling it in the direction of the arrow, the force measurement value Fγ as shown in FIG. c is output, and thereby the moving means MT moves the hand 5 in the direction in which the external force is made zero, that is, in the direction of the arrow in which the external force is applied. When you stop the hand HD at position P ₁ and release the external force,
The calculated force value Fγ also drops as shown in FIG. 1C, and accordingly, the composite command V'c also drops, and the hand 5 stops. Therefore, the object can be moved by external force without changing the speed control system, making direct teaching possible. [Embodiment] (a) Explanation of the configuration of an embodiment FIG. 2 is a configuration diagram of an embodiment of the present invention.
This is an example of an orthogonal robot. In the figure, the same components as those shown in FIG. ,10b
2 is a gate-type robot that positions the transport pallets 11a, 11b in the X-axis direction, and has a pair of support bases 20, 21 used on both sides of the A Z-axis block 22 that moves, a Z-axis movable part (arm) 23 that moves in the Z-axis direction, and a Y-axis that moves the Z-axis block 22, rotates the ball screw 24a, and drives it in the Y-axis direction along guides 25a and 25b. It has a shaft motor 24 and a Z-axis motor 26 which is provided on the Z-axis block 22 and drives the Z-axis arm 23 in the Z-axis direction via a ball screw feeding mechanism (not shown). 3 is the aforementioned force sensor, which consists of a leaf spring mechanism and a strain gauge, which converts the displacement of the leaf spring due to external force into an electronic signal using the strain gauge, and has four degrees of freedom in the X, Y, Z, and γ axes. 4 is a γ-axis motor, which is supported by the Z-axis arm 23 and rotates the force sensor 3 and hand 5 around the γ-axis; 5 is a vacuum suction band, which will be described later. 6th
As shown in the figure, a suction surface is provided at the tip of the cylindrical body and an intake tube is connected to an intake pump. 6 is a jig that holds a disk (magnetic disk plate) 9 on a pallet 11a. 7 is the base, palette 11b
The disc 9 is mounted on the disc and the disc 9 is attached to it. 80 is an operation panel for inputting commands and data operated by the operator; 81 is a memory for storing teaching data, etc.;
82 is a processor (hereinafter referred to as CPU),
It is composed of a microprocessor, etc., and reads the contents of the memory 81 during playback and gives commands to each part. 83 is a servo control part,
X-axis motor 10a of axis modules 1a, 1b,
10b, the Y-axis motor 24, the Z-axis motor 26, and the γ-axis motor 4 for position and speed control.
Command position CX ₂ , CX ₁ , CY from CPU82,
CZ and Cγ are input, and the current position PX ₂ , PX ₁ , PY, PZ, Pγ is input from the hand position detection circuit described later.
is fed back, and the commanded speeds Vcx to Vcγ are inputted from the synthesizing section 85, and servo control is performed based on these. 84 is a power amplifier that amplifies the input and outputs the X, Y, Z, and γ-axis motors 1.
0a, 10b, 24, 26, 4, and 85 is the above-mentioned combining section, which, as described later in _FIG . Something that takes the difference between the force control outputs PFX~PFγ and gives it to the servo control unit 83;
Reference numeral 86 denotes a teaching box, which is operated for teaching, and as described later in FIG. 4, has keys for instructing direct teach, keys for instructing movement of each axis, keys for instructing speed, and 87 is a force control unit which receives the detection outputs FX to Fγ of the force sensor 3 as will be described later in FIG.
A device that converts this into digital values FX~Fγ, sets a dead zone, and outputs control outputs PFX~PFγ. 88 is a hand position detector, which is provided in the motors 10a, 10b, 24, 26, and 4 of each axis. The current position PX ₁ , PX ₂ , PY, PZ, Pγ of each axis is determined from the output of the rotary encoder, and the current position of the hand 5 is obtained. 89 is a bus, a CPU 82, a memory 81, an operation panel 80, The teaching box 86, servo control section 83, synthesis section 85, force control section 87 and hand position detection circuit 88 are connected to exchange data and commands. FIG. 3 shows detailed circuits of the force control section 87, the combining section 85, the servo control section 83, and the power amplifier 84. In the figure, the same components as those shown in FIG. Speed command VX
~ Those that output the difference with VZ, 804 ~ 807
is the dead band part, and the dead band width from CPU82
WX to Wγ are set to provide a dead zone to the force measurement values FX to Fγ, and 808 is a switch that allows/disallows the input of the force measurement values FX to Fγ, and provides a force feedback On/off is controlled by CPU82, 809
are analog/digital converters (referred to as A/D converters), which convert the analog force measurement values FX, FY, FZ, Fγ from the force sensor 3 into digital values and output them to the switch 808; 83d are servo circuits,
Current position and command position CX from position detector 88,
84a to 84d are power amplifiers that perform position control based on the difference between CY, CZ, and Cγ, and speed control based on the difference between the command speed V′X to V′γ and the actual speed. A drive current is supplied to the motor of each axis based on the output of the circuits 83a to 83d. Therefore, the switch unit 80 is controlled by the CPU 82.
8 is off, the output of the force sensor 3 (that is, the output of the A/D converter 809) is in the dead zone 8
04,805,806,807 is not input,
The force feedback is back-off, and the command positions CX, CY, CZ, Cγ and command speed from the CPU82
VX, VY, VZ, and Vγ are input as they are to servo circuits 83a to 83d for each axis, and position and speed are controlled. On the other hand, the switch section 808 is controlled by the CPU 82.
is on, the force feedback is on, and the output of the force sensor 3 is in the dead band portions 804 to 80.
7 as control outputs PFX, PFY, PFZ, and PFγ, which are input to synthesis units 800 to 803, and synthesized outputs VX', VX', and command speeds VX, VY, VZ, and Vγ.
VY', VZ', V'γ are servo circuits 83a to 83d
is given as a speed command. There are two X-axes, the X1-axis and the X2-axis, but 1
Although shown as one X-axis servo circuit 83a and an amplifier 84a, there are actually two. (b) Description of teaching box and teaching data FIG. 4 is a configuration diagram of the teaching box 86 in the configuration of FIG. 2. In the figure, 860 is a speed changeover switch, and depending on the rotation of the switch, the speed can be set to high speed (H), medium speed (M), or low speed (L).
861a to 865b are movement direction instruction keys for each axis, and 861a, 866
1b indicates movement in the direction of the X1 axis, respectively; 862a, 862b indicates movement in the direction of the X2 axis, 86
3a and 863b indicate movement in the Y-axis direction, respectively; 864a and 864b indicate movement in the Z-axis direction; 865a and 865b indicate movement in the γ-axis direction;
It instructs movement in the direction. 866 is a direct teach instruction key (referred to as DT instruction key), which instructs direct teach when pressed, and 867 is an EXIT (end) key, which instructs the end of one teaching. be. Switch 8 of the teaching box 86
60, each key 861a to 865 and DT key 8
The instructions of 66 and the corresponding processing of the CPU 82 are shown in the table below.

〔Effect of the invention〕

As explained above, according to the present invention, the following effects are achieved. A control section is provided which converts the detection output of the force detection means into a force command via a non-linear element that provides a dead zone, and controls the movement of the moving means with a composite movement command that combines the movement command and the force command. ,
One control system enables both indirect teaching and direct teaching, and the configuration can be simplified. In response to the operation of the first instruction means, a movement command corresponding to the movement instruction for teaching is created, and joint display is performed with external force adaptive control based on the composite movement command, so indirect teaching by external force adaptive control is possible. Therefore, smooth indirect teaching becomes possible. The detection output of the force detection means is converted into a force command via a nonlinear element that provides a dead zone, and the movement of the movement means is controlled by a composite movement command that combines the movement command and the force command. Even if the force detection means generates an external force detection output due to minute external forces such as noise, temperature drift,
It is possible to prevent the object from vibrating and making it difficult to teach the object. The detection output of the force detection means is converted into a force command via a non-linear element that provides a dead zone, and the movement of the moving means is controlled by a composite movement command that combines the movement command and the force command, so even during direct teaching, Appropriate resistance can be applied to the human hand, and direct teaching can be carried out easily.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the principle of the present invention, Fig. 2 is a block diagram of an embodiment of the present invention, Fig. 3 is a circuit diagram of the main part of the structure shown in Fig. 2, and Fig. 4 is a diagram of the teaching box of the structure shown in Fig. 2. Fig. 5 is a block diagram of the memory configured in Fig. 2, Fig. 6 is an explanatory diagram of operation in a working example, Fig. 7 is an operation flow diagram of teaching mode, and Fig. 8 is an explanatory diagram of operation in speed control mode. , FIG. 9 is an explanatory diagram of the relative position error correction operation, FIG. 10 is a flowchart of the suction operation in the playback mode, and FIG. 11 is an explanatory diagram of another embodiment of the present invention. In the figure, 3... force detection means, 5... hand (object), MT... moving means, 8... control unit, 86...
...Operation means.

Claims (1)

[Claims] 1. A moving means for moving an object, a force detecting means for detecting a force applied to the object, a first instruction means for instructing movement for indirect teaching, and a first instruction means for instructing direct teaching. In a teaching control method for an object moving device, the object moving device has an operating means having two instruction means, and is capable of direct teaching using the output of the force detecting means and indirect teaching using a movement command, wherein the detection output of the force detecting means is set in a dead zone. a control unit that converts the first command into a force command via a nonlinear element that gives the first command, and controls the movement of the moving means using a composite movement command that combines the movement command and the force command; In response to the operation of the second instruction means, create a movement command corresponding to the movement instruction for teaching, perform indirect teaching accompanied by external force adaptive control using the composite movement command, and in response to the operation of the second instruction means, A teaching control method for an object moving device, characterized in that direct teaching is performed using the force command generated by manual operation of the object. 2. The teaching control method for an object moving device according to claim 1, wherein the control unit creates a speed command as the movement command.