JPH08187687A - Control device for robot and hand device for robot - Google Patents

Abstract

PURPOSE: To quickly and surely perform mounting a part by additionally providing objective track control with compliance control to reduce mounting resistance between the parts, and similarly additionally providing control of rotating the part to reduce force necessary for mounting the part. CONSTITUTION: In a control device 7, an output data from a force sensor 8, arranged in a robot, is detected by a force detecting part 9. A mounting objective track relating to a mounted part of a mounting part is produced in a target track producing part 10, also to correct the produced target track based on the detected force data suitably in a target track producing part 11. Further based on the detected force data, position displacement and attitude displacement of the mounting part are calculated respectively in a compliance control part 12, also to similarly determined rotating the mounting part in a rotary track producing part 13. Each command value from the compliance control part 12 and from the track producing part 13 is synthesized in a PID control part 14, to respectively dispatch an operation command in each operating mechanism arranged in the robot 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a robot which inserts an insert part while detecting a force acting on the insert part held by a hand, and more particularly to a shaft and a roller. The present invention relates to a control device for performing a fitting operation of a cylindrical part such as a part at high speed.

[0002]

2. Description of the Related Art In recent years, automation of an assembly line by an industrial robot has been advanced, and more sophisticated work such as assembly of precision parts has been required of the robot. In the process of assembling precision parts, high relative positioning accuracy between parts may be required as in the case of inserting and fitting a ring-shaped roller part into a shaft part. In such an inserting operation, the robot is required to have a positioning accuracy of the order of several μm, but it may be very difficult to realize the above-mentioned accuracy with the current mechanical positioning accuracy of the robot.

Therefore, as a means for solving the above-mentioned problems, conventionally, a mechanism or control called a compliance mechanism or compliance control has been applied to a robot for inserting and inserting work.

The compliance mechanism is translated, for example, as a follow-up mechanism or an acceptance mechanism. That is, flexibility is provided by incorporating elastic elements such as springs and dampers in the hand (hand) of the robot, and the positioning error between the insertion component and the insertion component is absorbed by the flexibility, and the insertion component is inserted. Is a mechanism for inserting and mounting so as to follow the parts to be inserted.

On the other hand, the compliance control is translated as follow-up control or admission control, for example. That is, it is a method of realizing the same movement as the compliance mechanism on software.

In this compliance control, the insertion resistance of the insertion component when the insertion operation is performed (when the insertion component cannot be actually inserted (when a part of the insertion component collides with the end surface of the insertion component)) (Including) is detected, and control is performed such that the components are inserted while the inclination and the positional deviation of the components are finely corrected based on the insertion resistance.

That is, in all of these methods (mechanisms and controls), by providing the robot hand with a certain compliance (following property), the hand can be finely displaced with respect to an external force at the time of component insertion, It is intended to absorb a position error with respect to the component to be inserted.

[0008]

By the way, the above-mentioned conventional compliance mechanism and compliance control have problems to be solved as described below. First of all, the method using the compliance mechanism can directly realize the compliance operation by providing the robot hand with a mechanism having the optimum flexibility for the work, so that it is more stable than the method involving software such as the compliance control. And high-speed operation can be expected.

However, since the compliance mechanism cannot change the setting of the flexibility of the robot hand during the insertion operation, it can be used only for the insertion work of a specific type of component.

In general, if the flexibility of the hand is set to be large, the hand of the hand becomes softer and the followability is further improved, but on the contrary, proper insertion force cannot be obtained at the time of insertion operation and insertion is difficult. May be. However, if the flexibility is reduced, on the other hand, if the insertion component is a soft precision component formed of aluminum or the like, there is a risk that the component will be damaged by excessive insertion.

On the other hand, in compliance control in which a compliance mechanism is realized by software, there is a degree of freedom in which optimum flexibility can be set appropriately according to the work. But,
Since the method involves software, there is a problem that it is slightly inferior in speed and stability as compared with the compliance mechanism.

Also, in any of the above methods, good insertion is attempted by correcting only the posture of the insertion component without changing the insertion trajectory of the insertion component. Therefore, when the relative position or attitude error between the insertion component and the insertion component is relatively large, the contact force between the components increases as the components are inserted, and the compliance operation becomes impossible. There was a risk of scratching.

The present invention has been made in view of the above circumstances, and is intended for a robot capable of compensating for the drawbacks of the conventional compliance mechanism and compliance control and for inserting and inserting the insertion parts at high speed and with a small insertion force. An object of the present invention is to provide a control device and a robot hand device.

[0014]

A first means of the present invention is a robot for controlling a robot which has a hand and inserts an insertion component held by the hand into a predetermined insertion position of an insertion target component. In the control device, a force detection unit connected to the hand and configured to detect the insertion resistance force of the insertion component with respect to the insertion target component at predetermined time intervals, and a target trajectory generation unit that generates a target trajectory of the insertion component. And a trajectory correction unit that corrects the target trajectory generated by the target trajectory generation unit based on the detection result of the force detection unit, and the inserted component based on the detection result of the force detection unit at predetermined time intervals. A compliance control unit that determines the movement of the hand to correct the positional deviation and the posture of the insertion part with respect to
A rotation trajectory generation unit that determines to rotate the hand holding the insertion component based on the insertion resistance force detected by the force detection unit, a movement command from the compliance control unit, and a rotation trajectory generation And a follow-up controller that drives and controls the hand so as to follow the combined value.

The second means is a robot controller for controlling a robot having a hand and inserting and holding the insertion part held in the hand at a predetermined insertion position of the insertion target part, which is connected to the hand. A force detection unit that detects the insertion resistance force of the insertion component with respect to the insertion target component at predetermined time intervals, and a target trajectory generation unit that generates a target trajectory of the insertion component,
A trajectory correction unit that corrects the target trajectory generated by the target trajectory generation unit based on the detection result by the force detection unit, and the above-described component for the component to be inserted based on the detection result by the force detection unit at predetermined time intervals. It has a compliance control unit that determines the movement of the hand for correcting the position shift and posture of the insertion part, and a tracking control unit that drives and controls the hand so as to follow the movement command from the compliance control unit. A control device for a robot characterized by the above.

A third means is the robot control apparatus according to the first or second means, wherein the trajectory correction section corrects the position and orientation of the insertion part by the compliance control section, and When the insertion resistance becomes small, a detection means for detecting the fact based on the detection result of the force detection unit and a position and posture of the robot hand at that time are added to the target trajectory to newly add A control device for a robot, comprising: a correction means for correcting the target trajectory.

A fourth means is the robot control device according to the third means, wherein the detecting means of the trajectory correcting section causes the insertion resistance force detected by the force detecting section to once reach a predetermined threshold value. The robot control device is characterized in that it detects that the insertion resistance has become small by detecting the fact that it has fallen below the threshold value again after exceeding.

The fifth means is a robot control device for controlling a robot having a hand and inserting and holding the insertion part held by the hand at a predetermined insertion position of the insertion target part, which is connected to the hand. A force detection unit that detects the insertion resistance force of the insertion component with respect to the insertion target component at predetermined time intervals, and a target trajectory generation unit that generates a target trajectory of the insertion component,
A compliance control unit that determines the movement of the hand for correcting the positional deviation and the posture of the insertion component with respect to the insertion component based on the detection result by the force detection unit at predetermined time intervals, and the force detection unit. A rotation trajectory generation unit that determines to rotate the hand holding the insertion component based on the insertion resistance force detected by, a movement command from the compliance control unit, and a rotation command from the rotation trajectory generation unit. And a follow-up controller that drives and controls the hand so as to follow the combined value.

A sixth means is the robot controller according to the first or fifth means, wherein the rotational trajectory generating section is
The robot controller is characterized in that it is determined to rotate the hand holding the insertion part by an angle proportional to the insertion resistance force.

The seventh means has a hand for holding a cylindrical part or a shaft part, and a hand device for driving one hand to insert one part into the other part,
A main body for holding the hand, and when the insertion resistance force applied to the parts held by the main body and held by the main body becomes a predetermined value or more, the displacement in the insertion direction is converted into the displacement in the rotational direction of the hand, and A hand device, comprising: a rotation driving unit that rotationally drives the hand.

An eighth means is the hand device according to the seventh means, wherein the rotation driving means is fixed to the spiral shaft connected to the hand and to the main body in a state of being combined with the spiral shaft. It is characterized in that it has a nut for converting axial displacement of the spiral shaft into rotation of the spiral shaft, and a spring provided in the main body for restricting movement of the spiral shaft in the axial direction. It is a hand device.

[0022]

According to the first means, the compliance control can be performed while the target trajectory is being corrected, and by rotating the insertion component as necessary, this component can be smoothly inserted. Can be done.

According to the second and third means, the compliance control can be performed while correcting the target trajectory. According to the fourth, fifth, and sixth means, by rotating the insertion part as necessary, the insertion of this part can be smoothly performed. According to the seventh and eighth means, the force in the insertion direction when inserting the component can be converted into the rotation of this component, and the component can be inserted while rotating.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an example of a robot manipulator (hereinafter referred to as "robot") to which the control device of the present invention is applied. This robot is attached to a fixed frame 1.

This robot has a hand indicated by 2 in the drawing. The hand 2 is provided in a hand unit 3 shown in FIG. And this hand unit 3
Are held by an XYZθ drive mechanism 4 attached to the frame 1 and driving the hand unit 3 in the XYZθ directions.

The hand unit 3 includes a swinging mechanism 5 for swinging the hand 2 as shown by an arrow (a) in the figure, and a swinging mechanism of the hand 2 as shown by an arrow (b) in the figure. And a rotating mechanism 6 for rotating the same.

Therefore, the hand 2 has the XYZ.
The θ drive mechanism 4, the swinging mechanism 5, and the rotating mechanism 6 are positioned and driven in six axial directions. On the other hand, reference numeral 7 in the figure denotes the control device of the present invention. The XYZθ drive mechanism 4, the swinging mechanism 5 and the rotating mechanism 6 of the hand unit 3 are connected to the control device 7 and are operated by a command from the control device 7.

A force detection sensor 8 for detecting the insertion resistance force acting on the hand 2 is provided in the hand unit 3, and the detection result by the force detection sensor 8 is input to the control device 7. It has become so.

Next, the control device 7 will be described.
FIG. 2 is a block diagram showing a control system of the control device 7. This control system includes a force detection unit 9 that detects force data (insertion resistance force) from the force sensor 8 and a target trajectory generation unit that generates an insertion target trajectory of an inserted component with respect to an attached component. 1
0, a target trajectory correction unit 11 that appropriately corrects the target trajectory generated by the target trajectory generation unit 10 based on the force data detected by the force detection unit 9, and the force detection unit 9
The compliance control unit 12 for calculating the positional deviation and the attitude deviation of the insertion part based on the force data from
And a rotation trajectory generation unit 13 that determines the rotation of the insertion part based on the force data from the force detection unit 9, a command value from the compliance control unit 12, and a rotation trajectory generation unit 13 from the rotation trajectory generation unit 13. The PID control unit 14 is configured to combine the command value and issue an operation command to each mechanism provided in the robot.

Next, the function of each part will be described in more detail together with the operation of this robot. In this embodiment, as shown in FIG. 3, the roller component 15 as an insertion component is
An example will be described in which the shaft 16 as the component to be inserted is inserted and attached.

In this case, first, the shaft 16 is fixed to the frame 1 side of the robot, and the roller part 15 is fixed.
Is held by the hand 2. This state is simplified and shown in FIG. In the figure, numeral 8 indicates the force sensor for detecting the insertion resistance force acting on the hand 2.

First, the target trajectory generation unit 10 and the force detection unit 9 will be described. The target trajectory generation unit 10 produces a trajectory ((a) shown in FIG. 4 (a)) that is expected to be inserted into the shaft 16 if the roller component 15 is driven along the trajectory. To generate.

The control device 7 operates the hand 2 when inserting the roller part 15 onto the shaft 16,
First, the roller part 15 is moved along the target trajectory (a).

At this time, if there is an error in the relative position and orientation between the roller part 15 and the shaft 16,
As shown in FIG. 4A, the roller component 15 (the lower surface of the roller component) abuts, for example, the end surface (upper end surface) of the shaft 16 and a force F1 is applied to the roller component. The force detector 9 takes in the force data detected by the force sensor 8 at every predetermined sampling time (detection time).

The force detector 9 converts the force data into force data at a compliance center 18 which will be described later, and then the force controller 9 controls the compliance controller 12, the target trajectory corrector 11, and the rotary trajectory generator 13. Send out.

Next, the compliance control section 12 will be described. The compliance control unit 12 includes a virtual compliance mathematical model that realizes a compliance mechanism including a spring and a damper on software.

In the compliance control section 12, for example, as shown in FIG. 4A, it is as if the center of mass of the roller part 15 is reached when the force F1 acts on the roller part 15. The compliance center 18 that behaves in the above manner is set at a specific position of the hand 2.

As described above, the force detecting section 9 converts the force data F2 from the force sensor 8 into force data F3 (insertion resistance force) at the compliance center 18, and the compliance is calculated. Input to the control unit 12.

Then, the compliance control unit 12
Calculates the positional deviation and attitude correction amount of the roller component 15 with respect to the shaft 16 based on the force data (direction and size of the force data F3 applied to the compliance center 18).

This calculation is performed at each sampling time when the force data is input from the force detection unit 9 (force sensor 8) and is sent to the PID control unit 14. The PID control unit 14 issues an operation command to the robot on the basis of the calculated value, and detects the position / position of the roller component 15
A posture correction operation and an insertion operation are performed.

That is, the roller part 15 is shown in FIG.
In the process of being driven along the target trajectory (a) shown in (a), the position and orientation of the shaft 1 are corrected at every sampling time, and the shaft 1 is rotated as shown in FIG. 4 (b).
Aligned with the upper end of 6. Then, after this, the shaft 16 is inserted and attached. Such an operation is generally called a compliance operation.

Next, the operation of the target trajectory correction unit 11 will be described. In this target trajectory correction unit 11, the roller component 1 is detected from the force data F3 detected by the force detection unit 9.
The force component in the insertion direction of No. 5 (Fs shown in FIG. 5A: hereinafter referred to as "insertion force") is taken out, and this force is monitored as shown in the graph of FIG.

In the graph of FIG. 5, the vertical axis indicates the insertion force Fs,
The horizontal axis shows the insertion time t. That is, the insertion time t
The change in the insertion force Fs with the passage of is shown. Then, the target trajectory correcting unit 11 appropriately corrects the target trajectory, which is the basis of the movement of the hand 2, based on the result of the monitoring as described below.

FIG. 5A is a graph (comparative example) showing the change in the insertion force Fs when the target trajectory is not corrected, and FIG. 5B is the target trajectory correction unit. 11 is a graph (present invention) showing a change in the insertion force Fs when the correction is performed according to No. 11.

The force Fs in the inserting direction causes a large positional deviation between the roller part 15 (inserting part) and the shaft 16 (inserted part) and an error in the posture, which makes it difficult to insert. In the case (FIG. 4 (a)), the value becomes large, and after that, the compliance operation corrects the position and the posture of the roller component 15 and the insertion is relatively smoothly performed. The value becomes smaller (in the case of FIG. 4B).

In this target trajectory correction unit 11, the insertion force Fs
To an appropriate threshold Ff (300 g in FIG. 5)
f) is provided. When the insertion force Fs once exceeds the threshold value Ff and then becomes a value below the threshold value Ff again (Fig. 5).
(A), point A in (b)), target trajectory correction unit 11
Captures the position and orientation of the hand 2 at this time.

Then, by adding the offset amount of the position and attitude data of the hand 2 fetched at this time to the desired trajectory (a) generated by the desired trajectory generator 10, the corrected desired trajectory (b) To generate. Then, the corrected target trajectory (b) is replaced with the previous target trajectory (a).

FIG. 4B shows this state. In this figure, due to the compliance operation, the inner diameter portion of the roller component 15 and the upper end of the shaft 16 coincide with each other, which reduces the force in the insertion direction. The control device 7 takes in the position and orientation of the hand 2 in this state, and based on this, replaces the target trajectory (a) with a target trajectory (b) closer to the more accurate insertion direction.

Therefore, after that, the roller component 1 is
The reference numeral 5 is inserted into the shaft 16 along the target trajectory (b) while the positional deviation and the posture are corrected by the compliance operation.

The target trajectory corrector 11 continues to correct the target trajectory (b) every time the insertion force Fs exceeds the threshold Ff. For example, in the insertion process, as shown in FIG. 6A, the inner surface of the roller part 15 may come into contact with the shaft part 16 at two points, and the insertion force Fs may increase. At this time, the operation of the compliance control unit 12 causes the roller component 15 to operate.
6B is corrected as shown in FIG. 6B and the contact between the roller part 15 and the shaft 16 is released, so that the insertion force Fs is once reduced.

However, even after this, if the roller part 15 is inserted along the original target trajectory (b), the roller part 15 and the shaft 16 may contact again. . For this reason, the target trajectory correction unit 11 is
The position and orientation of the hand in (b) are taken in, a new target trajectory (c) is generated based on this, and the original target trajectory (b) is replaced. As a result, subsequent insertion can be smoothly performed.

Next, the operation of the rotational trajectory generator 13 will be described. On the other hand, the rotation trajectory generator 13 determines the insertion force Fs based on the force data input from the force detector 9.
If the (insertion resistance) becomes greater than the specified value,
It is decided to rotate the hand 2 with respect to the central axis of the roller part 15.

The rotation operation is performed when the contact angle (pressure angle) between the roller part 15 and the shaft 16 is large, as in the case where the roller part 15 is fitted to the shaft 16.
Is rotated with respect to the shaft 16 to reduce the relative contact angle between them and reduce the force required for insertion.

That is, in FIG. 7, the insertion force in the target trajectory (c) direction is indicated by Fs in the figure. Then, the contact angle at this time is represented by θ, which is shown in FIG. On the other hand, in FIG. 7, the force in the rotation direction is defined as Fe. In FIG. 8, when the combined force of the rotational force Fe and the insertion force Fs is taken on the slope with an angle θ, the contact angle of this combined force is θe as shown in the figure.

At this time, as shown in the figure, since there is a relation of θ> θe, the contact angle becomes smaller when the inserting operation and the rotating operation are combined. This can reduce the force required for insertion.

The rotation trajectory generator 13 also determines the angle and speed at which the roller component 15 is rotated.
This rotation angle is, for example, an angle proportional to the magnitude of the force of the roller component 15 in the insertion direction. Further, the rotation speed is set to be a speed that increases in proportion to the force in the insertion direction.

However, the rotation angle has an upper limit (for example, 1
80 °) is provided, and if it exceeds this, it is switched to reverse rotation. By such operation, the above
If the rack part 15 can be moved, thereafter, only a dynamic frictional force smaller than the static frictional force is exerted between them, so that after that, the insertion can be performed without rotating.

Next, the operation of the PID controller 14 will be described. The rotation command from the rotation trajectory generation unit 13 is input to the PID control unit 14. The PID control unit 14 combines the movement command value from the compliance control unit 12 and the rotation command value from the rotation trajectory generation unit 13 to generate a final operation command value of the hand 2 for the robot. To do.

By the command from the PID control unit 14,
Each mechanism of the robot performs the above-described operation, and by adding the target trajectory correcting operation and the rotating operation to the compliance operation, the roller part 15 is inserted and attached.

If such insertion is carried out, the roller part 15 finally collides with the flange portion of the shaft 16 shown by 16a in FIG. By this,
Since the force Fs in the inserting direction becomes excessive, it is possible to detect that the insertion of the roller component 15 is completed. This state can be detected from the portion indicated by B in the graph shown in FIG.

By the above operation,
The insertion of the rack part 15 is completed. The above operation is shown in FIG.
It is shown in the flowchart shown in. According to the configuration described above, there are the effects described below.

First, the compliance controller 12
By adding the target trajectory correction unit 11, the insertion parts (roll
The insertion force (insertion resistance force) generated between the component 15) and the component (shaft 16) to be inserted can be reduced, and the component can be smoothly inserted.

That is, in the conventional compliance control, the position and orientation of the inserted component is corrected, but the target trajectory is not corrected. For this reason, the number of times the inserted component and the component to be inserted contact each other increases, and the insertion resistance force increases. For this reason, the number of compliance operations may increase, and insertion may take time.

However, in the present invention, the target trajectory of the roller part 15 is corrected by correcting the target trajectory each time the insertion resistance force (insertion force Fs) rubs the constant threshold value Ff. It is possible to approach the shaft 16 in the correct insertion direction.

As a result, the number of contacts between the two can be reduced and the contact angle can be reduced, so that the insertion resistance can also be reduced. As a result, there is an effect that the above-mentioned insertion component can be quickly inserted.

This is shown in the graph of FIG.
It is proved by comparing with the graph of (b). The graph of FIG. 5A is a graph showing the change in the insertion force Fs when the target trajectory is not corrected as described above, and FIG. 5B is the graph when the target trajectory is corrected. It is a graph which shows the change of insertion force Fs.

In the graph of FIG. 5A, when the insertion of the roller part 15 is started after passing the point A, the insertion force F is set.
Although s decreases once, since the target trajectory (a) remains, the roller component 15 and the shaft 16 immediately contact and ascend. Moreover, since this target trajectory (a) has a large gap from the accurate trajectory, the insertion force Fs generated at the time of contact is Fs.
(Insertion resistance) becomes considerably large.

On the other hand, in the graph of FIG. 5 (b), after passing the point A, the target trajectory (a) is corrected to a trajectory (b) closer to the more accurate insertion trajectory. Part 1
Even if the shaft 5 and the shaft 16 come into contact with each other, the increase in the insertion force Fs is small.

Further, even after the insertion is started, the target trajectory (a) in FIG. 5A remains the same, so that the insertion force Fs immediately rises even if the compliance operation is performed. Therefore, this insertion force Fs changes at a high value.

On the other hand, in FIG. 5 (b), since the target trajectory is corrected, the insertion force Fs (insertion resistance) is small even when both are in contact with each other. Therefore, the insertion force Fs changes at a value lower than that in FIG. 5A, as shown in the figure.

That is, according to the present invention, by adding the target trajectory correcting operation to the compliance operation, the insertion resistance can be kept small throughout the entire insertion process, so that the insertion can be performed smoothly. Therefore, as shown by B in the figure, the insertion of the roller component 15 can be completed earlier than in the case of FIG.

Secondly, the compliance controller 12
By adding the rotation trajectory generation unit 13, the insertion parts (low
The contact angle between the component part and the component to be inserted (shaft) can be reduced, and the effect of quickly inserting the component can be achieved.

That is, in the conventional insertion / replacement operation only in compliance control, when the roller part 15 and the shaft 16 are fitted together, the insertion resistance between them is excessive and the parts stop. There were times when compliance control didn't work.

However, according to the present invention, by rotating the roller part 15 in the above-mentioned case, the insertion resistance force acting between the roller part 15 and the shaft 16 can be reduced. There is an effect that the roller part 15 can be quickly inserted and attached.

This is shown in the graph of FIG.
This can be understood by comparing with the graph of 0. The graph of FIG. 5 shows the change of the insertion force when only the target trajectory correction operation is added to the compliance operation, and FIG. 10 shows the change of the insertion force when the rotation operation is further added.

In FIG. 10, after passing through the insertion start point A, the rotation operation is added at the point C where the insertion force Fs becomes maximum. By adding this rotation, the subsequent insertion force can be reduced and the roller part 15 can be smoothly inserted and inserted. Therefore, as shown by B in the figure, compared with the case of FIG. 5B, the insertion of the roller parts can be completed earlier.

The time from the start of insertion (point A) to the end of insertion (point B) in FIG. 10 is 1/2 of that in the case of only the conventional compliance control of FIG. 5 (a).
It can be shortened to

Thirdly, according to the present invention, since the insertion force can be reduced as described above, the insertion operation can be performed without applying much force to the insertion component (roller component 15). It can be performed. Therefore, there is an effect that it is possible to reduce damage to the insertion parts and the non-insertion parts (the shaft 16) due to the excessive insertion.

Next, a second embodiment of the present invention will be described with reference to FIG. The description of the same components as those in the first embodiment will be omitted. The first
In the second embodiment, the rotation of the roller component 15 is determined by the rotation trajectory generation unit 13 by software, but in the second embodiment, similar rotation is performed in the insertion direction. This is realized mechanically without using software by using a mechanism that converts displacement into rotational motion.

FIG. 11 shows the hand unit 3
Is a hand device (mechanism) of the present invention provided at the tip of the. The hand device includes a hand unit 20 having a hand 2 that holds a roller component 15, and a main body 21 that holds the hand unit 20.

In the main body 21, the insertion force Fs applied to the roller part 15 held by the hand 2 is applied to the hand 2
A spiral shaft / nut mechanism 22 for converting into a force Fe in the direction of rotating the (roller part 15) is provided.

The spiral shaft 23 constituting the spiral shaft / nut mechanism 22 is provided in the middle of the central shaft 24 extending upward from the hand portion 20, and the nut 25 is provided in the main body 2.
It is provided at the lower end portion of the case 26 that constitutes part 1.

The upper end of the center shaft 24 extends into the case 26 to form a flange 24a. Then, between the upper surface of the flange portion 24a and the upper wall surface inside the case 26, a spring indicated by 27 in the drawing is inserted in a compressed state.

The lower end of the spring 27 is supported by a circular seat 30 held by a rotary bearing 29 on the upper surface of the flange portion 24a. In addition, a support shaft 31 shown in the drawing is erected on the upper surface of the circular seat 30, and the spring 27 is externally fitted to the support shaft 31.
The upper end of the support shaft 31 is supported by the case 26 so as to be slidable in the vertical direction, and is configured to move up and down as the hand unit 20 moves up and down.

The spring 27 has a function of determining the value of the insertion force required to start the rotation of the hand 2 by restricting the axial movement of the spiral shaft 23.

That is, the value of the insertion force required to rotate the hand 2 is the restoring force of the spring 27, the weight of the hand portion 20 and the spiral shaft / nut mechanism 2.
It is determined by the balance with the axial resistance of 2. Therefore, by determining the strength of the spring 27, it is possible to determine the value of the predetermined insertion force for starting the rotation of the hand 2.

Since the spiral shaft / nut mechanism 22 converts the displacement in the axial direction into the displacement in the rotational direction, the hand portion 20 moves relative to the case 26 when the rotation is started. To rise (immerse). When the upper surface of the hand portion 20 comes into contact with the lower surface of the case 26, the hand portion 20 stops rotating.

When the insertion force Fs decreases below the predetermined insertion force value, the restoring force of the spring 27 pushes it out of the case 26 to restore the state shown in FIG. Has become.

According to the second embodiment, there are the effects described below. First, as in the case where the roller component 15 is fitted to the shaft 16 as described above, there are cases where the insertion force Fs is excessive and the smooth insertion cannot be performed only by compliance control. According to the invention, by rotating the roller part 15, there is an effect that the force required for insertion is reduced and smooth insertion can be performed.

That is, if only the conventional compliance control is used for attachment, the hand 2 is too soft and the fitting force between the roller part 15 and the shaft 16 is too small unless the compliance flexibility is set properly. There is a case that the insertion force to overcome is not obtained. On the other hand, if the setting of the hand 2 is too hard, the above-mentioned roller component 1 is forcibly inserted.
5 and the shaft 16 may be damaged.

However, according to the present invention, even when the setting of the hand 2 is soft, the force Fs in the inserting direction and the rotational direction are changed as already described with reference to FIGS. 7 and 8 in the first embodiment. By combining the force Fe with each other, it is possible to reduce the contact angle between the parts and reduce the force required for the insertion, so that the insertion of the parts can be continued.

Therefore, there is an effect that the roller part 15 can be securely and securely inserted (fitted) to the shaft 16. Secondly, in the first embodiment, the rotation of the roller component 15 is performed based on the determination of the rotation trajectory generation unit 13, but this method requires software (control device). Since it is interposed, it may be inferior in followability and it may take time to insert.

According to the present invention, however, the rotation of the roller part 15 is mechanically realized without the intervention of software, so that it depends on the insertion resistance of the roller part 15. Rotation can be performed without a time delay. Therefore, there is an effect that the roller part 15 can be quickly inserted and attached.

The second embodiment is not limited to the above-mentioned structure, but may have the structure shown in FIG. 12, for example. The structure shown in FIG. 12 has the same function as the structure shown in FIG. 11 described above. However, the structure (FIG. 11) described above is different in that the spiral shaft / nut mechanism 22 is provided in the lower part of the main body 21, whereas the structure shown in FIG. 12 is provided in the upper part of the main body 21. .

Further, in accordance with this, in this mechanism, the spring 27 and the support shaft 31 are not provided in the central portion of the circular seat 30, but the spring 27 and the support shaft 31 are symmetrical at two positions on both sides of the spiral shaft / nut mechanism 22. It is provided in.

Even with such a structure, the insertion force Fs applied to the roller part 15 can be converted into the force Fe for rotating the roller part 15, so that the second embodiment is different from the second embodiment. The same effect can be obtained.

The present invention is not limited to the first and second embodiments, but can be variously modified without changing the gist of the invention. For example, in the first and second embodiments, the roller component 15 is inserted into the shaft 16 by holding the roller component 15 with the hand 2. Alternatively, the insertion operation may be carried out by holding at.

In the first and second embodiments, both the target trajectory correction unit 11 and the rotational trajectory generation unit 13 are provided, but only one of them may be provided. Even if only one of them is used, compared with the case of only the conventional compliance control, the insertion parts can be efficiently inserted.

Further, if only the target trajectory correction section 11 is added, the insertion parts do not have to be cylindrical parts as in the above embodiment, and can be used in any combination of parts. .

Further, in the above embodiment, when the roller part 15 and the shaft 16 are deviated from each other at the initial stage as shown in FIG. 4A, the compliance of the roller part 15 is used to control the roller part 15. The posture is corrected, but if this deviation is large, it is possible that the posture cannot be corrected by the compliance control. In this case, other positioning means may be used to correct the posture of the roller component. The other positioning means may be mechanical or may be controlled.

Further, in the above-mentioned one embodiment, the end of the mounting of the roller part 15 is judged only by the excessive force Fs in the insertion direction. When the shape is complicated and a protrusion or the like exists in the middle, the protrusion may sometimes cause an excessive force in the insertion direction, which may result in determination of the insertion end. Therefore, the following control may be performed as another means for determining the attachment end.

That is, the compliance control section is provided with “insertion distance ≧ predetermined (end) insertion distance” as the first end condition and “operation time ≧ limit time” as the second end condition, and either one of them is set. A control is added to determine that the insertion has been completed when satisfied. According to such a configuration,
There is an effect that it is possible to determine the end regardless of the force in the insertion direction.

[0103]

As described above, according to the present invention, by adding the target trajectory control to the compliance control, it is possible to reduce the insertion resistance between the parts, so that the parts can be quickly inserted. And it can be performed without damaging the component.

By adding the control for rotating the component to the compliance control, the force required for inserting the component can be reduced, and the component can be securely and promptly inserted.

Furthermore, since a mechanism for converting the insertion resistance force (displacement in the insertion direction) of the component into the rotational force (displacement in the rotation direction) of the component is provided, this component can be securely and safely inserted. There is an effect that can be.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing an embodiment of the present invention.

FIG. 2 is a block diagram showing a control system of the same.

FIG. 3 is a perspective view showing an example of an insertion part and an insertion part.

FIG. 4 is an explanatory diagram showing a compliance operation and a target trajectory correction operation.

FIG. 5 is a graph showing a change in force in the insertion direction.

FIG. 6 is an explanatory view showing a compliance operation and a target trajectory correction operation.

FIG. 7 is an explanatory view similarly showing rotational driving of components.

FIG. 8 is an explanatory diagram for explaining a combination of the rotational force and the insertion force.

FIG. 9 is also a flowchart.

FIG. 10 is a graph showing a change in force in the insertion direction.

FIG. 11 is a vertical sectional view showing a hand device of the robot.

FIG. 12 is a vertical sectional view showing another embodiment of the present invention.

[Explanation of symbols]

2 ... Hand, 9 ... Force detection unit, 10 ... Target trajectory generation unit, 1
1 ... Target trajectory correction unit, 12 ... Compliance control unit,
13 ... Rotary trajectory generation unit, 14 ... PID control unit (following control unit), 15 ... Roller component (insertion component), 16 ... Shaft (insertion component), 20 ... Hand unit, 21 ... Main body, 22 …
Spiral shaft / nut mechanism (rotational drive means), 23 ... spiral shaft,
25 ... nuts.

Claims (8)

[Claims] 1. A robot control device for controlling a robot having a hand and inserting and holding an insertion component held by the hand at a predetermined insertion position of an insertion target component, the controller being connected to the hand, Based on the detection result by the force detection unit, a force detection unit that detects the insertion resistance force of the attachment component with respect to the attachment component at predetermined time intervals, a target trajectory generation unit that generates the target trajectory of the insertion component, and A trajectory correction unit that corrects the target trajectory generated by the target trajectory generation unit, and corrects the positional deviation and posture of the insertion component with respect to the insertion component based on the detection result of the force detection unit at predetermined time intervals. And a compliance control unit that determines the movement of the hand, and determines that the hand holding the insertion component is rotated based on the insertion resistance force detected by the force detection unit. It has a rolling trajectory generation unit, a movement control command from the compliance control unit, and a rotation control command from the rotation trajectory generation unit, and a follow-up control unit that drives and controls the hand so as to follow the combined value. Robot control device characterized by: 2. A robot control device for controlling a robot having a hand and inserting and holding an insertion part held by the hand at a predetermined insertion position of an insertion target part, the control device being connected to the hand, Based on the detection result by the force detection unit, a force detection unit that detects the insertion resistance force of the attachment component with respect to the attachment component at predetermined time intervals, a target trajectory generation unit that generates the target trajectory of the insertion component, and A trajectory correction unit that corrects the target trajectory generated by the target trajectory generation unit, and corrects the positional deviation and posture of the insertion component with respect to the insertion component based on the detection result of the force detection unit at predetermined time intervals. A compliance control unit that determines the movement of the hand, and a tracking control unit that drives and controls the hand so as to follow the movement command from the compliance control unit. Control apparatus for a robot according to claim. 3. The robot controller according to claim 1 or 2, wherein the trajectory correction unit corrects the position and orientation of the insertion component by the compliance control unit, and the insertion resistance of the insertion component. When the force becomes small, a new target trajectory is obtained by adding detection means for detecting that fact based on the detection result of the force detection section and the position and orientation of the robot hand at that time to the target trajectory. A controller for a robot, characterized in that it has a correction means for correcting. 4. The robot control apparatus according to claim 3, wherein the detecting means of the trajectory correcting section is configured to detect the insertion resistance force detected by the force detecting section once again after exceeding a predetermined threshold value. A robot controller characterized in that it detects that the insertion resistance has decreased by detecting the fact that it has fallen below a threshold value. 5. A robot controller for controlling a robot having a hand and inserting and holding an insertion part held by the hand at a predetermined insertion position of an insertion part, the control device being connected to the hand, A force detection unit that detects the insertion resistance force of the attached component with respect to the attached component at predetermined time intervals, a target trajectory generation unit that generates the target trajectory of the insertion component, and the detection result at each predetermined time by the force detection unit. Based on the insertion resistance force detected by the force detection unit, and a compliance control unit that determines the movement of the hand for correcting the positional deviation and the posture of the insertion component with respect to the insertion target component. The rotation trajectory generation unit that determines to rotate the hand holding the insertion component, the movement command from the compliance control unit, and the rotation command from the rotation trajectory generation unit are combined, and the combined result is obtained. Control apparatus for a robot, characterized in that it comprises a tracking control unit for driving and controlling the hand so as to follow the value. 6. The robot controller according to claim 1 or 5, wherein the rotation trajectory generation unit rotates a hand holding the insertion component by an angle proportional to the insertion resistance force. A robot controller characterized by being determined. 7. A hand device having a hand for holding a cylindrical part or a shaft part, and inserting one part into the other part by driving the hand, a main body for holding the hand, and a main body for holding the hand. When the insertion resistance force applied to the component held in the hand is equal to or more than a predetermined value, the displacement in the insertion direction is converted into the displacement in the rotation direction of the hand, and the rotation drive means for rotationally driving the hand is provided. A hand device characterized by having. 8. The hand device according to claim 7, wherein the rotation driving means is fixed to the spiral shaft connected to the hand and to the main body in a state of being combined with the spiral shaft. A hand device comprising: a nut that converts axial displacement into rotation of the spiral shaft; and a spring that is provided in the main body and restricts movement of the spiral shaft in the axial direction.