JP2003071760A - Assembly robot - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control movements such as position and attitude with high precision without receiving the influence of error of position and attitude in an arm tip part. SOLUTION: The arm tip part of an assembly robot 100 is provided with a position attitude sensor 106 detecting position and attitude of the tip part and a compensation mechanism 109 capable of compensating by moving position and attitude of an end effector 102. A hand tip error computing part 107 computes an error for the position and attitude detected by the position attitude sensor 106 when driving and controlling an arm to a target position and the position of the arm tip part required when working. A compensation mechanism target position computing part 108 determines a control target value of position and attitude for the compensation mechanism 109 to compensate the position of the end effector 102 by the obtained error value to drive and control the robot. At this time, the form of the arm is not changed, and the position and attitude can be compensated with high precision.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an assembling robot used for assembling and disassembling products, and more particularly to correcting position / orientation error during operation of a robot arm for more highly accurate work. Assembly robot that can
Furthermore, the present invention relates to a control method thereof, a program for causing a computer to execute the method, and a computer-readable recording medium recording the program.

[0002]

2. Description of the Related Art Conventionally, when a multi-joint robot is placed in a production system for assembly or disassembly, the angular position of each joint of the robot is calculated from the required position / orientation of the hand or movement locus. The calculated value serves as a target value of the servo motor that drives each joint, and each joint is driven by an individual servo system, and positioning control is performed to perform a multi-degree-of-freedom operation.

However, in such an articulated robot,
Due to the backlash of the reducer of the servo motor and the elastic deformation of the arm structure, even if the angular position of the motor is accurate, an error occurs in the position and orientation of the end effector at the end of the arm. As a method of measuring the acceleration of the arm tip and the position of the arm root and suppressing the vibration of the arm tip based on these values, there is JP-A-8-47882 "vibration damping device".

This vibration damping device comprises an accelerometer attached to the tip of the robot arm to be controlled, an arm root position sensor attached to the base of the arm, and an actuator attached to the arm base. The result of calculating the command to move the arm to the target position based on the value obtained by comparing the detection value from the root position sensor with the arm tip speed setting value and the arm tip position setting value is sent to the actuator. The vibration at the tip of the arm is reduced by using it as a control signal.

[0005]

However, this method can reduce the error due to the vibration of the tip of the arm, but the static deflection and the backlash of the reducer of the motor which change depending on the attitude of the arm. It is difficult to correct the error due to.

In order to solve the above-mentioned problems of the prior art, the present invention eliminates the backlash of the reducer of the servo motor and the arm structure portion of the servo motor that drives each joint during assembly and disassembly work using a multi-joint robot. An assembly robot capable of highly accurate motion control of position, posture, etc. without being affected by errors in the position, posture, etc. of the arm tip portion caused by elastic deformation, a control method therefor, and a computer for the method. It is an object to provide a program to be executed and a computer-readable recording medium recording the program.

[0007]

[Means for Solving the Problems]
In order to achieve the object, an assembly robot according to the invention of claim 1 calculates a target position of each drive motor of each joint forming an arm from the position, posture, or locus of the arm tip portion necessary for work, In a multi-joint assembling robot that positions each drive motor individually to perform assembly or disassembly work, the position of the tip is detected when the arm is provided at the tip of the arm and the tip is position-controlled to a target position. Position detecting means, a hand end error calculating means for detecting the position of the arm tip portion based on the output of the position detecting means, and calculating an error with respect to the position of the arm tip portion necessary for working, the arm tip portion, and the arm tip. Correction means, which is provided between the end effector and the end effector and is movable to correct the position of the end effector, and the hand error calculation means. Correction mechanism target position calculation means for determining a position control target value for the correction means and drivingly controlling the position of the end effector based on the calculated error value. .

According to the invention of claim 1, an error in the position of the arm tip portion due to the arm structure of the assembly robot or the like can be corrected by the correction means arranged at the arm tip portion. There is no need to change the form of the arm and no new position error occurs. Therefore, the arm tip portion can be highly accurately positioned and controlled without being affected by the position error due to the backlash of the speed reducer that drives the assembly robot, the elastic deformation of the arm, or the like.

Further, in the assembly robot according to the invention of claim 2, in the invention according to claim 1, the position to be taken by the tip of the arm is set in order to control the positioning of the tip of the arm to a target position. Equipped with hand position setting means,
It is characterized in that the hand error calculation means calculates a position error based on the position of the end effector set by the hand position setting means and the position detected by the position detection means.

According to the second aspect of the present invention, the position when the positioning control of the arm to the target position is set in advance, and an error from the detected position can be obtained by reading this position, which is simple. Highly accurate positioning control can be performed.

The assembly robot according to a third aspect of the present invention is the assembly robot according to any one of the first and second aspects, wherein the arm is provided at the tip of the arm, and the tip is positioned and controlled to a target position. In this case, the hand end error calculation means detects the posture of the arm tip portion based on the output of the posture detection means, and an error with respect to the posture of the arm tip portion necessary for work is provided. And the correction means is movable to correct the attitude of the end effector, and the correction mechanism target position calculation means calculates the end effector of the end effector based on the error value calculated by the hand error calculation means. In order to correct the attitude, the correction means determines the attitude control target value and controls the drive.

According to the third aspect of the present invention, since the error in the posture of the arm tip portion due to the arm structure of the assembly robot or the like can be corrected by the correction means arranged at the arm tip portion, the error can be corrected. There is no need to change the form of the arm and no new posture error occurs. Therefore, the posture of the arm tip can be controlled with high accuracy without being affected by the posture error caused by the backlash of the speed reducer that drives the assembly robot and the elastic deformation of the arm.

Further, in the assembly robot according to a fourth aspect of the present invention, in the invention according to the third aspect, the posture to be taken by the tip of the arm is set in order to position and control the tip portion of the arm to a target position. Equipped with hand posture setting means,
The hand end error calculation means may calculate a position error based on the attitude of the end effector set by the hand end attitude setting means and the attitude detected by the attitude detection means.

According to the invention of claim 4, the posture when the positioning control of the arm to the target position is set in advance, and the posture can be read to obtain an error from the detected posture, which is simple. Highly accurate posture control is possible.

The assembly robot according to a fifth aspect of the present invention is the assembly robot according to any one of the first to fourth aspects, wherein the end effector is controlled when the tip of the arm is positionally controlled to a target position. To the reaction force applied to the end effector set in advance by detecting the reaction force generated in the end effector by the output of the force detection means and the force detection means for detecting the reaction force generated during the work And a correction mechanism target position calculating means for adjusting the reaction force applied to the end effector to the set value based on the error value calculated by the reaction force error calculating means. It is characterized in that the correction means determines a control target value of the reaction force and controls the drive.

According to the fifth aspect of the present invention, the reaction force exerted on the arm tip portion due to the arm structure or the like at the time of work that requires the end effector of the assembly robot to generate a force of a predetermined magnitude from a predetermined direction. Since the error can be corrected by the correction means arranged at the tip of the arm, it is not necessary to change the form of the arm to correct the error, and a new reaction force error is not generated. Therefore, the tip of the arm can be driven and controlled with high accuracy to a predetermined reaction force without being affected by the reaction force error due to the backlash of the speed reducer that drives the assembly robot or the elastic deformation of the arm.

The assembly robot according to a sixth aspect of the present invention is the assembly robot according to the fifth aspect of the invention, when the end effector generates a work when the tip end portion of the arm is positionally controlled to a target position. Reaction force setting means for presetting the reaction force of the end effector, and the reaction force error calculating means detects the reaction force of the end effector set by the reaction force setting means and the force sense detecting means. It is characterized in that an error of the reaction force is calculated based on the reaction force.

According to the sixth aspect of the present invention, the reaction force when the arm is positionally controlled at the target position is set in advance, and the reaction force can be read to obtain an error from the detected reaction force. Therefore, the work requiring the desired reaction force can be easily and highly accurately driven and controlled.

Further, in the invention according to any one of claims 1 to 6, the correction means includes an arm fixing base fixed to the arm tip portion, and an end effector base fixed to the end effector. A plurality of movable links, each of which is connected between the arm fixed base and the end effector base and is expandable and contractible, each having a plurality of degrees of freedom in a translational direction and a rotational direction. May be.

According to the present invention, since a plurality of expandable and contractible movable links are used for the correction means, it is possible to suppress the occurrence of error even if an inertial force or a work reaction force is applied during operation. The posture and reaction force correction control is possible.

Further, the target position of each drive motor of each joint forming the arm is calculated from the position, posture, or locus of the arm tip portion required during work, and each drive motor is individually positioned to assemble or disassemble. A control method in an articulated assembly robot, which is for performing work, comprising a correction means capable of changing position and attitude between an end of an arm and an end effector. The position detection step of detecting the position of the tip of the arm in a state of being driven to position, the position of the arm tip set in advance, and the position error of the arm tip required during the work based on the detected position. A position error calculating step for calculating, and a position correction for correcting and controlling the position of the end effector with respect to the correction means based on the calculated position error. Or a method characterized by comprising the steps, a.

According to the present invention, the position error of the arm tip portion due to the arm structure of the assembling robot is corrected by the control of the correcting means of the arm tip portion, so that the form of the arm is changed to correct the error. There is no need to do so and no new position error occurs. Therefore, the arm tip portion can be highly accurately positioned and controlled without being affected by the position error due to the backlash of the speed reducer that drives the assembly robot, the elastic deformation of the arm, or the like.

Further, in the above invention, a posture detecting step of detecting the posture of the tip of the arm in a state where the drive motors are positioned and driven to the target position, a preset posture of the tip of the arm, and the detection. A posture error calculation step of calculating a posture error of the arm tip portion necessary for work based on the calculated posture, and a posture correction for correcting and controlling the posture of the end effector with respect to the correction means based on the calculated posture error. The method may include a step.

According to the present invention, the posture error of the arm tip portion due to the arm structure of the assembly robot is corrected by the control of the correcting means of the arm tip portion, so that the form of the arm is changed to correct the error. There is no need to do this, and no new posture error occurs. Therefore, the posture of the arm tip can be controlled with high accuracy without being affected by the posture error caused by the backlash of the speed reducer that drives the assembly robot and the elastic deformation of the arm.

Further, in the above invention, a force sense detecting step of detecting a reaction force generated at the work with respect to the end effector in a state in which each drive motor is positioned and driven to the target position is preset. A reaction force error calculating step of calculating a reaction force error based on the reaction force applied to the end effector and the detected reaction force, and an end effector to the correction means based on the calculated reaction force error. A reaction force correction step of controlling the drive so that the applied reaction force reaches the set value may be included.

According to the present invention, when the end effector of the assembly robot needs to generate a force of a predetermined magnitude from a predetermined direction, the error of the reaction force applied to the arm tip portion due to the arm structure or the like is eliminated. Since the correction can be performed by the control of the correction means arranged at the tip of the arm, it is not necessary to change the form of the arm to correct the error, and a new reaction force error is not generated. Therefore, the tip of the arm can be driven and controlled with high accuracy to a predetermined reaction force without being affected by the reaction force error due to the backlash of the speed reducer that drives the assembly robot or the elastic deformation of the arm.

Further, in the above invention, the correcting means is provided between the tip end portion of the arm and the end effector, and has a plurality of movable links having variable link lengths, and the position correcting step is performed. And a drive command step of variably controlling the link length of each movable link of the correction means in accordance with the control values of the corrections obtained in the posture correction step and the reaction force correction step. May be used.

According to the present invention, the plurality of movable links are controlled in accordance with the control value when the error is corrected by the correcting means, so that even if an inertial force or a work reaction force is applied during the operation, the error in the correcting means is corrected. Suppress the occurrence of high-precision position, posture,
Also, the correction control of the reaction force becomes possible.

It may also be a computer program characterized by causing a computer to execute any one of the methods described above.

According to the present invention, the method described in any one of the above can be executed by the computer, and the correction control of the position and posture of the arm tip portion of the assembly robot and the reaction force can be executed using the computer. As a result, the accuracy of the arm drive control can be improved.

Further, it may be a computer-readable recording medium characterized by recording the above-mentioned program.

The recording medium according to the present invention records the program to be executed by the computer described above, so that the program can be machine-readable, whereby the operation of the invention can be realized by the computer. .

[0033]

BEST MODE FOR CARRYING OUT THE INVENTION Referring to the accompanying drawings, an assembly robot according to the present invention, a control method therefor, a program for causing a computer to execute the method, and a computer-readable recording medium recording the program are described. A preferred embodiment will be described in detail.

[First Embodiment] FIG. 1 is an overall configuration diagram showing a first embodiment of an assembly robot according to the present invention.
In the robot 100, a plurality of arms 100a are connected by a plurality of joints 100b, and an end effector 102 is provided at the tip of the free end arm. The robot 100 is drive-controlled by the drive control means 115.

The drive control means 115 has a hand position / posture setting unit 101 for setting the position / posture values to be taken by the end effector 102 provided at the tip of the arm, and the robot 1.
00 has a motor target position calculation unit 103 for calculating the target position of the drive motor of each joint, and a drive command unit 104 for driving the drive motor of each joint of the robot 100 based on the target position data of the drive motor.

Further, at the tip of the arm of the robot 100,
A position / orientation sensor 106 and a correction mechanism 109 are provided. The position and orientation sensor 106 detects the position and orientation of the end effector 102 at the tip of the arm. The position / orientation sensor 106 is configured by a three-dimensional laser position sensor, a combination of a three-dimensional magnetic sensor and a gyro sensor, or the like. The position / orientation sensor 106 may be configured to be able to output a position signal and an attitude signal independently by using, for example, a configuration in which a configuration related to position detection and a configuration related to orientation are combined. The correction mechanism 109 is composed of an actuator that corrects the posture and position of the arm tip portion.

The hand error calculation unit 107 calculates an error between the position / posture of the end effector 102 at the arm tip set by the hand position / posture setting unit 101 and the position / posture detected by the position / posture sensor 106. The correction mechanism target position calculation unit 108 determines a control target value for the correction mechanism 109 based on the error calculated by the hand error calculation unit 107. The correction drive command unit 110 drives the actuator of the correction mechanism 109 to correct the position / orientation error of the end effector 102 at the arm tip.

Regarding the operation of the assembling robot having the above configuration,
This will be described with reference to the flowchart of FIG. First, the hand position / orientation setting unit 101 sets the position / orientation to be taken by the end effector 102 at the arm tip of the robot 100 based on the work procedure of the robot and the relative positional relationship with the work target (step S201). Next, the motor target position calculation unit 103 uses the end effector 1 at the tip of the arm.
Robot 1 to take the position and posture that 02 requires
The target position of the drive motor of each joint of No. 00 is calculated (step S202).

Next, the drive command unit 104 drives the drive motor of each joint of the robot 100 based on the calculated drive motor target position data (step S203). At this time, the position and orientation sensor 106 detects the position and orientation of the arm tip portion of the robot 100 (step S204),
In the hand error calculation unit 107, the hand position / posture setting unit 10
End effector 10 at the tip of the arm set in 1.
The error between the position / orientation of No. 2 and the position / orientation detected by the position / orientation sensor 106 is calculated (step S20).
5).

Then, the correction mechanism target position calculation unit 108 determines a control target value for the correction mechanism 109 based on the obtained error (step S206), and the correction drive command unit 110 drives the actuator of the correction mechanism 109. Then, the position / orientation error of the end effector 102 at the tip of the arm is corrected (step S207).

Next, FIG. 3 shows the above-mentioned correction mechanism 109.
FIG. As shown, in the present embodiment,
A highly rigid parallel link mechanism 300 is used as a specific configuration example of the correction mechanism 109.

The parallel link mechanism 300 includes an arm fixing base 301 provided at the base end side, an arm fixing base 301 provided at the arm tip end of the robot 100, that is, an end effector base 302 provided at the end effector 102 side, and these arm fixings. The base 301 and the end effector base 302 are composed of six movable links 303 connected in series. Arm fixed base 30
1. The end effector base 302 is formed in a disk shape, and the six movable links 303 are arranged at equal intervals along the edge of the disk.

The movable link 303 is an arm 3 having a predetermined length.
03a and spherical guides 304 (304a, 304b) respectively provided at both ends of the arm 303a, the arm fixing base 301 and the end effector base 302.
It is connected to the. The arm 303a is configured so that the link length changes as the built-in linear motion actuator expands and contracts.

By changing the link length of these six movable links 303, the arm fixing base 301
The relative position and the posture of the end effector base 302 (end effector 102) with respect to can be moved within a range of a total of 6 degrees of freedom (3 degrees of freedom in translation direction, 3 degrees of freedom in rotation direction).

According to the configuration described above, the error in the position and orientation of the tip portion due to the structure of the arm mechanism of the assembly robot 100 can be corrected by the correction mechanism 109 at the tip portion of the arm. At this time, it is not necessary to change the form such as the posture of the arm to correct the error, and no new error is generated by the correction mechanism. Therefore, the operation of the end effector 102 at the tip of the arm can be controlled without being affected by the backlash of the speed reducer of the servo motor that drives each joint and the error due to the elastic deformation of the arm structure.

The position and orientation sensor 10 is attached to the tip of the arm.
With the configuration in which 6 is arranged, the position of the arm tip can be directly detected, and the error in the position of the arm tip can be accurately detected. Accordingly, the position and orientation of the end effector 102 at the arm tip can be corrected with high accuracy by the correction mechanism 109.

Further, by using the highly rigid parallel link mechanism 300 as the correction mechanism 109, it is possible to correct a plurality of, for example, 6 degrees of freedom, so that even if an inertial force or a work reaction force is applied during operation, the correction mechanism 109 It is possible to reduce the occurrence of error, and it is possible to accurately control the position and orientation of the end effector 102 at the end of the arm to control the operation.

[Embodiment 2] FIG. 4 is an overall configuration showing Embodiment 2 of an assembly robot according to the present invention. The same components as those in the first embodiment described above are designated by the same reference numerals. In the second embodiment, the work reaction force during the work of the assembly robot 100 is detected, and the position and orientation of the end effector 102 are corrected.

The drive control means 400 requires the hand position / orientation setting unit 101 and the end effector 102 for setting the position / orientation to be taken by the end effector 102 from the work procedure of the robot and the relative positional relationship with the work target. Motor target position calculation unit 103 that calculates the target position of the drive motor of each joint of the arm in order to obtain the desired position / orientation.
And a drive command unit 1 for driving the drive motor of each joint of the robot 100 based on the target position data of the drive motor.
It is configured to have 04.

A force sensor 401 and a correction mechanism 109 are provided at the arm tip of the robot 100. The force sensor 401 detects an assembly reaction force generated in the end effector 102 when the robot 100 is working.
In the reaction force setting unit 402, the reaction force generated in the end effector 102 when the assembly and disassembly work is normally performed is set in advance. The reaction force error calculation unit 403
An error between the reaction force preset in the reaction force setting unit 402 and the reaction force detected by the force sensor 401 is calculated.

The correction mechanism target position calculation unit 108 uses the correction mechanism 1 based on the error calculated by the reaction force error calculation unit 403.
The control target value of 09 is determined. Correction drive command unit 110
Drives the actuator of the correction mechanism 109 and corrects the assembly reaction force of the end effector 102 at the end of the arm to a set value.

Regarding the operation of the assembling robot having the above configuration,
This will be described with reference to the flowchart of FIG. First, the hand position / orientation setting unit 101 sets the position / orientation that the end effector 102 should take from the work procedure of the robot 100 and the relative positional relationship with the work target (step S501). Next, the motor target position calculation unit 103
In order to obtain the position / posture required by the end effector 102, the target position of the drive motor of each joint of the arm is calculated (step S502).

Next, the drive command unit 104 drives the drive motor for each joint of the robot 100 based on the target position data of the drive motor (step S503). At this time, the force sensor 401 detects the assembly reaction force applied to the end effector 102 by the work of the robot 100 (step S504).

Then, the reaction force error calculation unit 403 detects the reaction force generated in the end effector 102 when the assembly or disassembly work preset in the reaction force setting unit 402 is normally performed, and the force sensor 401. The error of the reaction force detected by is calculated (step S505).

Next, the correction mechanism target position calculation unit 108 determines the control target value of the correction mechanism 109 based on the obtained error (step S506), and the correction drive command unit 11
When 0, the actuator of the correction mechanism 109 is driven, and the assembly reaction force of the end effector 102 at the end of the arm is corrected to a set value (step S507).

According to the above configuration, the work reaction force applied to the tip of the arm can be detected, and the position and orientation of the end effector 102 can be corrected by the correction mechanism 109, and the speed reducer of the servo motor that drives each joint. It is possible to perform a desired operation with high accuracy without being affected by the backlash and the error due to the structural elastic deformation of the arm mechanism.

The correction mechanism target position calculation unit 108
In addition to the above-described correction of the reaction force error, the control target value of the correction mechanism 109 may be determined and output to correct the position and orientation described in the first embodiment.

The assembly robot 1 of the embodiment described above
00 can be used for both assembling work for assembling parts and disassembling work for parts, and in any case, the position and orientation of the arm tip can be corrected to perform highly accurate motion control. .

That is, according to the present embodiment, since the error in the position of the arm tip portion due to the arm structure of the assembly robot or the like can be corrected by the correcting means arranged at the arm tip portion, the error can be corrected. There is no need to change the form of the arm and no new position error occurs. Therefore, the arm tip can be controlled with high accuracy without being affected by the position error due to the backlash of the speed reducer that drives the assembly robot, the elastic deformation of the arm, and the like.

Further, according to the present embodiment, the position when the arm is positionally controlled to the target position is set in advance, and it is possible to read this position and obtain an error from the detected position, which is simple. Highly accurate positioning control can be performed.

Further, according to the present embodiment, the error in the posture of the arm tip portion due to the arm structure of the assembly robot or the like can be corrected by the correction means arranged at the arm tip portion, so that the error can be corrected. There is no need to change the form of the arm and no new posture error occurs.

Further, according to the present embodiment, the posture when the arm is positionally controlled at the target position is set in advance, and it is possible to read this posture and obtain an error from the detected posture, which is simple. The effect is that highly precise posture control can be performed.

Further, according to the present embodiment, the reaction force exerted on the arm tip portion due to the arm structure or the like at the time of work that requires the end effector of the assembly robot to generate a force of a predetermined magnitude from a predetermined direction. Since the error can be corrected by the correction means arranged at the tip of the arm, it is not necessary to change the form of the arm to correct the error, and a new reaction force error is not generated.

Further, according to the present embodiment, the reaction force when the arm is positionally controlled at the target position is set in advance, and the reaction force can be read to obtain an error from the detected reaction force. Therefore, it is possible to easily and precisely control the work requiring the desired reaction force.

Further, according to the present embodiment, since a plurality of expandable and contractible movable links are used for the correction means, it is possible to suppress the occurrence of errors even if an inertial force or a work reaction force is applied during the operation, which is high. It is possible to perform accurate position, orientation, and reaction force correction control.

The control method described in the present embodiment can be realized by executing a program prepared in advance on a computer such as a personal computer. This program is a hard disk, floppy (registered trademark) disk, CD-ROM,
It is executed by being recorded in a computer-readable recording medium such as MO or DVD and being read from the recording medium by the computer. The program can be distributed via the recording medium and a network such as the Internet.

[0067]

As described above, according to the first aspect of the present invention, the target of each drive motor of each joint forming an arm is determined based on the position, posture, or locus of the arm tip portion required during work. In a multi-joint assembly robot that calculates the position, positions each drive motor individually, and performs assembly or disassembly work, the robot is provided at the tip of the arm,
Position detecting means for detecting the position of the tip portion when the tip portion is positioned and controlled at a target position, and the position of the arm tip portion detected by the output of the position detecting means, and the position of the arm tip portion necessary for working A hand error calculation means for calculating an error with respect to the arm, a correction means provided between the arm tip portion and an end effector arranged at the arm tip portion, the correction means movable to correct the position of the end effector, A configuration including a correction mechanism target position calculation unit that determines a position control target value for the correction unit to drive and control the position of the end effector based on the error value calculated by the hand error calculation unit. Because,
Since an error in the position of the arm tip portion due to the arm structure of the assembly robot or the like can be corrected by the correction means arranged at the arm tip portion, it is not necessary to change the shape of the arm to correct the error, and a new position No error is generated. Therefore, there is an effect that the tip end portion of the arm can be controlled with high accuracy without being affected by the position error due to the backlash of the speed reducer that drives the assembly robot, the elastic deformation of the arm, and the like.

According to the invention of claim 2, claim 1
In the invention described in (3) above, there is provided a hand position setting means for setting a position to be taken by the tip of the arm in order to control the positioning of the arm tip portion to a target position, and the hand error calculation means is the hand position setting means. Since the position error is calculated based on the position of the end effector set in step 1 and the position detected by the position detecting means, the position when the arm is positionally controlled to the target position is set in advance. Further, it is possible to obtain an error from the detected position by reading this position, and it is possible to easily perform highly accurate positioning control.

According to a third aspect of the present invention, in the invention according to any one of the first and second aspects, when the arm is provided at the tip portion and the tip portion is positionally controlled to a target position. The hand tip error calculating means detects the posture of the arm tip portion based on the output of the posture detecting means, and calculates an error with respect to the posture of the arm tip portion necessary for work. The correction means is movable so as to correct the attitude of the end effector, and the correction mechanism target position calculation means calculates the attitude of the end effector based on the error value calculated by the hand error calculation means. Since the correction means determines the posture control target value and performs drive control for correction, the posture error of the arm tip portion due to the arm structure of the assembling robot, etc. Since can be corrected by the correcting means disposed on the arm tip, does not generate an error in the new attitude is not necessary to change the form of arms for error correction. Therefore, there is an effect that the posture of the tip end portion of the arm can be controlled with high accuracy without being affected by the posture error caused by the backlash of the speed reducer that drives the assembly robot, the elastic deformation of the arm, and the like.

According to the invention of claim 4, claim 3
In the invention described in (3) above, there is provided a hand posture setting means for setting a posture that the tip of the arm should take in order to position and control the tip portion of the arm, and the hand error calculation means is the hand posture setting means. Since the posture error is calculated based on the posture of the end effector set in step 6 and the posture detected by the posture detection means, the posture when the arm is positionally controlled to the target position is set in advance. Further, there is an effect that an error from the detected posture can be obtained by reading out this posture, and highly accurate posture control can be easily performed.

According to the invention of claim 5, claim 1
In the invention according to any one of claims 4 to 4, force sense detecting means for detecting a reaction force generated at the end effector during work when the tip end portion of the arm is positionally controlled to a target position, And a reaction force error calculating means for detecting a reaction force generated in the end effector by the output of the force sense detecting means and calculating an error with respect to a reaction force applied to the end effector set in advance. Is a configuration for deciding the control target value of the reaction force to the correction means so that the reaction force applied to the end effector becomes the set value, based on the error value calculated by the reaction force error calculation means, and performing drive control. Therefore, when the end effector of the assembly robot needs to generate a force of a predetermined magnitude from a predetermined direction, the end of the arm caused by the arm structure etc. Since the error of the reaction force can be corrected by arranged the correction means to the arm tip portion that does not generate an error of a new reaction force is not necessary to change the form of arms for error correction. For this reason, the effect that the arm tip can be drive-controlled with high precision to a predetermined reaction force without being affected by the reaction force error due to the backlash of the reduction gear that drives the assembly robot, the elastic deformation of the arm, and the like. Play.

According to the invention of claim 6, claim 5
In the invention described in (1) above, there is provided a reaction force setting means for presetting a reaction force generated at the time of the work on the end effector when the tip portion of the arm is positionally controlled to a target position, The error calculation means is a reaction force of the end effector set by the reaction force setting means,
Since the error of the reaction force is calculated based on the reaction force detected by the force detection means, the reaction force when the arm is positioned and controlled at the target position is set in advance, and this reaction force is read out. It is possible to obtain an error from the reaction force detected by the operation, and it is possible to easily and precisely control the work requiring a desired reaction force.

Further, according to another invention, in the invention described in any one of claims 1 to 6, the correction means comprises:
A plurality of arm fixed bases fixed to the arm tip, end effector bases fixed to the end effector, a plurality of arm fixed bases, and end effector bases, each of which is extendable and movable, are movable links. Since it is configured to have a plurality of degrees of freedom in the translational direction and the rotational direction, a plurality of expandable telescopic movable links are used for the correction means, so that even if an inertial force or a work reaction force is applied during operation, an error may occur. Since it is possible to suppress the occurrence of the above, there is an effect that the correction control of the position, the posture, and the reaction force can be performed with high accuracy.

According to another aspect of the invention, the target position of each drive motor of each joint forming the arm is calculated from the position, posture, or locus of the arm tip portion required during work, and each drive motor is individually calculated. A control method in a multi-joint assembly robot having a correction means capable of changing the position and orientation between the tip of the arm and the end effector, the assembly method or the disassembly work being performed by positioning the A position detection step of detecting the position of the tip of the arm in a state where each drive motor is positionally driven to the target position, a preset position of the arm tip, and a position necessary for the work based on the detected position. A position error calculating step of calculating a position error of the arm tip portion, and a position of the end effector with respect to the correcting means based on the calculated position error. Since the configuration is provided with the position correction process for positive control, the position error of the arm tip portion due to the arm structure of the assembly robot or the like is corrected by the control of the correction means of the arm tip portion. There is no need to change the form of the arm, and no new position error occurs. Therefore, there is an effect that the tip end portion of the arm can be controlled with high accuracy without being affected by the position error due to the backlash of the speed reducer that drives the assembly robot, the elastic deformation of the arm, and the like.

According to another invention, in the above invention, a posture detecting step of detecting the posture of the tip of the arm in a state in which each of the drive motors is positionally driven to the target position, and the preset posture is preset. A posture error calculation step of calculating a posture error of the arm tip portion required during work based on the posture of the arm tip and the detected posture, and an end effector for the correction means based on the calculated posture error. Since it is configured to include a posture correction step for correcting and controlling the posture of the robot, the posture error of the arm tip portion due to the arm structure of the assembly robot is corrected by the control of the correction means of the arm tip portion. Therefore, there is no need to change the form of the arm, and a new posture error does not occur. Therefore, there is an effect that the posture of the tip end portion of the arm can be controlled with high accuracy without being affected by the posture error caused by the backlash of the speed reducer that drives the assembly robot, the elastic deformation of the arm, and the like.

According to another invention, in the above invention, a force for detecting a reaction force generated at the time of operation with respect to the end effector in a state where each drive motor is positionally driven to the target position. Sense detection step, a reaction force applied to a preset end effector, based on the detected reaction force, a reaction force error calculation step of calculating an error of the reaction force, and based on the calculated reaction force error, Since the reaction force correction step of driving and controlling the reaction force applied to the end effector to the correction means to the set value is included, the end effector of the assembly robot has a force of a predetermined magnitude from a predetermined direction. Since the error of the reaction force applied to the arm tip portion due to the arm structure or the like can be corrected by the control of the correction means arranged at the arm tip portion when the work that needs to generate Does not generate an error of a new reaction force is not necessary to change the form of arms for error correction. For this reason, the effect that the arm tip can be drive-controlled with high precision to a predetermined reaction force without being affected by the reaction force error due to the backlash of the reduction gear that drives the assembly robot, the elastic deformation of the arm, and the like. Play.

According to another invention, in the above invention, the correcting means is provided between the tip end portion of the arm and the end effector, and has a plurality of movable links with variable link lengths. A drive command for variably controlling the link length of each movable link of the correction means in accordance with the correction control values obtained in the position correction step, the attitude correction step, and the reaction force correction step. Since the configuration including the process includes a configuration in which a plurality of movable links are controlled according to the control value when the error is corrected by the correction unit, even if an inertial force or a work reaction force is applied during operation, the error in the correction unit It is possible to suppress the occurrence of the generation and to perform highly accurate correction control of the position, posture, and reaction force.

According to another invention, since the method described in the above invention is configured to be executed by a computer, the position and posture of the arm tip of the assembly robot and the reaction force are corrected using the computer. As a result, the control can be executed, and the precision of the arm drive control can be improved.

According to another aspect of the invention, the above-mentioned program is recorded, so that the program can be read by a machine, whereby the above-described operation can be realized by a computer. Play.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram according to a first embodiment of an assembly robot of the present invention.

FIG. 2 is a flowchart showing drive control contents according to the first embodiment of the assembly robot of the present invention.

FIG. 3 is a perspective view showing a correction mechanism used in the assembly robot of the present invention.

FIG. 4 is an overall configuration diagram showing a second embodiment of an assembly robot of the present invention.

FIG. 5 is a flowchart showing drive control contents according to the second embodiment of the assembly robot of the present invention.

[Explanation of symbols]

100 robots 100a arm 100b joint 101 Hand position / posture setting unit 102 End effector 103 Motor target position calculation unit 104 Drive command section 106 Position and orientation sensor 107 Minus error calculator 108 correction mechanism target position calculation unit 109 correction mechanism 110 Correction drive command unit 115 Drive control means 300 parallel link mechanism 301 Arm fixed base 302 End effector base 303 Movable link 303a arm 304 (304a, 304b) spherical surface guide 400 drive control means 401 force sensor 402 Reaction force setting section 403 Reaction force error calculator

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takuya Uchida             1-3-3 Nakamagome, Ota-ku, Tokyo Stocks             Company Ricoh (72) Inventor Tadakatsu Harada             1-3-3 Nakamagome, Ota-ku, Tokyo Stocks             Company Ricoh (72) Inventor Kenichi Yoshimura             1-3-3 Nakamagome, Ota-ku, Tokyo Stocks             Company Ricoh F-term (reference) 3C007 AS06 BS10 KS05 KS17 KS20                       KS34 LT14 MT04

Claims (6)

[Claims] 1. A target position of each drive motor of each joint forming an arm is calculated from the position, posture, or locus of the arm tip portion required during work, and each drive motor is individually positioned to assemble or disassemble. In a multi-joint assembly robot for performing work, position detection means is provided at the tip of the arm and detects the position of the tip when the tip is positioned and controlled at a target position, and the output of the position detection means Provided between the hand error calculation means for detecting the position of the arm tip and calculating an error with respect to the position of the arm tip required at the time of operation, the arm tip and the end effector arranged at the arm tip. Correction means movable to correct the position of the end effector, and the end effector based on the error value calculated by the hand end error calculating means. The correction means to position the assembly robot, characterized in that to determine the control target value and a correction mechanism target position calculating means for controlling driving of the in order to correct the position of the connectors. 2. A hand position setting means for setting a position to be taken by the tip of the arm in order to control the position of the arm tip portion to a target position, wherein the hand error calculation means is the hand position setting means. The assembly robot according to claim 1, wherein a position error is calculated based on the set position of the end effector and the position detected by the position detection means. 3. A posture detecting means, which is provided at a tip portion of the arm, for detecting a posture of the tip portion when the tip portion is position-controlled to a target position, and the hand error calculating means comprises the posture detecting means. The posture of the arm tip portion is detected from the output of the above, and an error with respect to the posture of the arm tip portion necessary for work is calculated, and the correction means is movable to correct the posture of the end effector. The position calculation means is characterized in that, based on the error value calculated by the hand error calculation means, in order to correct the attitude of the end effector, the correction means determines a control target value of the attitude and controls the drive. The assembly robot according to claim 1. 4. A hand posture setting means for setting a posture to be taken by the tip of the arm in order to control the position of the tip of the arm to a target position, wherein the hand error calculation means is the hand posture setting means. The assembly robot according to claim 3, wherein an attitude error is calculated based on the set attitude of the end effector and the attitude detected by the attitude detecting means. 5. A force sense detecting means for detecting a reaction force generated at the end effector when the arm is positioned and controlled to a target position, and an output of the force sense detecting means. Reaction force error calculating means for detecting a reaction force generated in the end effector and calculating an error with respect to a reaction force applied to the end effector set in advance, wherein the correction mechanism target position calculating means is the reaction force error calculating means. The control target value of the reaction force is determined and drive-controlled by the correction means so that the reaction force applied to the end effector becomes the set value, based on the error value calculated in step 4. The assembly robot according to any one of 1. 6. A reaction force setting means for setting in advance a reaction force generated at the end effector when working when positioning the tip of the arm to a target position is controlled, and the reaction force error is provided. The calculation means calculates a reaction force error based on the reaction force of the end effector set by the reaction force setting means and the reaction force detected by the force sense detection means. The assembly robot described in 1.