JPS6069706A - How to calibrate the robot coordinate system - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (5) Technical field of the invention Does misfired EiA involve multiple joints? With regard to arm-shaped robots, especially robots that require coordinate conversion processing from a Cartesian coordinate system to a robot-specific joint coordinate system during control.
The present invention relates to a method for calibrating a four-pot coordinate system to improve the overall operating accuracy of the system.

(B) Background of the technology Industrial robots are used in a wide range of applications, including bathing, painting, and assembly work. Recently, it has been used for the sheath-tight assembly of small electronic components, and its operation requires precision. Accuracy that can be achieved by a robot includes the accuracy of reproducing a previously taught position and the accuracy of positioning in an absolute orthogonal coordinate system defined for the robot. Reproducibility is the repeatability of the variation in position and orientation when the robot is actually moved under full manual control, the desired position and orientation of the tip is taught, and the positioning to that state is attempted a total number of times. be. Positioning accuracy refers to the absolute accuracy regarding the difference between the commanded position and orientation of the robot tip and the position and orientation actually reached by the robot.

Teach-and-play robots require high repeatability, but absolute accuracy is not a priority. However, when all robots perform tasks programmed in a robot language or created using a robot simulator, or when a robot handles objects based on position data of objects detected by a visual recognition device using a TV camera, etc. For example, high absolute precision is required in addition to high repeatability. In addition, if a robot has high absolute accuracy, the position of parts magazines, various devices, objects to be assembled, etc. placed around the robot during assembly work can be determined by the location of the entire robot. When creating the entire work environment, you can safely place all the components accurately and measure the positional relationship between the robot and the components in advance without making any troublesome work noises. Become good.

By the way, an articulated robot has joint units that can rotate and bend the mantissa, all connected in the form of links, but when controlling this robot on an absolute orthogonal coordinate system, the desired joint can be determined from the position and orientation of the tip. Perform calculation to convert to angle. This conversion formula includes the length of each arm and the rotation angle of each joint from the origin of each joint as parameters. Here, the length of the arm has a deviation from the design value due to machining errors in component parts during robot manufacture. Furthermore, when assembling the robot, errors occur in the attachment of each joint. Therefore, what is the joint origin and arm length during design? Even if all the robots are controlled using this command, the operation according to the command value cannot be realized.

The above-mentioned robot languages, simulators, visual recognition devices, etc. make it easier to operate complex robots, reduce the burden of work instruction, and provide robots with additional functions. However, to make full use of these functions, the robot must have absolute precision. As a way to improve the absolute accuracy, it is possible to manufacture the arm completely accurately by increasing the machining accuracy, or to adjust the attachment of each joint accurately, but it is difficult and costly to do so. do not have.

In Japanese Patent Application No. 57-43778 entitled "Robot Arm Coordinate Determination Method," the Ministry of the Invention and others proposed a method for positioning the tip of a robot at a certain calibration point and determining all joint origins from multiple sets of posture information at that position. ing. In this method, it is not necessary to measure the entire position of the calibration points. However, when positioning the robot tip at the 21 calibration points,
If a measurement error is included, the influence of this unknown error may be amplified, for example, several tens of times. The reason for this is that, because it is not explicitly used in the calculation of the complete correction of the position of the positioned point in space, the true position of the calibration point may shift slightly during the repeated calculations. One example is receiving something. If the position of the calibration point in the space of the absolute orthogonal coordinate system defined for the robot can be measured in front of the vehicle and used in a single-direction and full-correction gauge, the influence of measurement errors can be reduced.

(q Purpose and structure of the invention The purpose of the present invention is to solve the above-mentioned point t. The overall objective is to be able to obtain high absolute accuracy after robot assembly is completed based on multiple sets of posture information at measured calibration positions.Therefore, the robot coordinate system calibration method of the present invention , an arm-shaped robot having a plurality of joints, a control means for driving the tip of the robot on an orthogonal coordinate system, and a rotation angle detection means for detecting rotation angle sounds of the joints provided at the valley joints of the robot. , a storage means for storing the detected rotational angle variation, and a displacement detecting means for detecting the total displacement in the , a step of measuring at least one calibration position in which the entire tip of the robot is positioned; and a step of measuring the entire rotation angle of each joint in each posture by positioning the tip of the robot at the calibration position. Based on the process of detection and storage, the rotation angles of the plurality of joints stored above, and the arm length at the time of design, the installation of each joint of the robot during assembly will be based on the error 2 and the arm length at the time of manufacture. The process of calculating the deviation of the robot and the installation of each joint are the actual origin position obtained from the error and the actual size of the arm obtained from the deviation of the arm length, and the coordinate conversion process performed by the control means of the robot. It is characterized by the process of evaluating all the calibration results and the process of evaluating the calibration results.The following description will be made with reference to all the drawings.

(To) Basic Idea of the Invention Before describing specific embodiments of the invention, the basic idea of the invention will be described.

For a robot composed of an arbitrary number of joints and combinations of joints, is it possible to display vectors of the rotation angles of the joints (hereinafter referred to as joint angles) from the true origin position after assembly and the arm length? It is expressed as in equation (1).

In the following, () represents a transposed vector.

Then, a Cartesian coordinate system (hereinafter referred to as
A measurement reference position vector k l'=(x, y, z)T provided at the tip of the robot in the absolute coordinate system (referred to as the absolute coordinate system).

Coordinate transformation matrix i A between each joint (A is a 4×4 matrix representing rotation and translation wJ?), Cartesian coordinate system defined at the tip of the robot (during the daytime, for convenience, referred to as the 1-nd coordinate system)
The measurement reference position vector in = (Xh.

yh, zh)T, as is well known, the following (2)
The relationship of the formula holds true.

The coordinate transformation matrix T from the hand coordinate system to the absolute coordinate system is the joint angle ω. Since the arm length 1LIo is included as all elements, the entire equation (2) is expressed as a function as shown in equation (3).

IP”X (6G, Lo, I()...
・・・・・・：・・・・・・・・・・・・・・・・・・
(3) Here, @o and Loil'ic are deviations l@ from the known joint angle 01 arm length at the time of design, respectively.

Suppose that iL is included. This is expressed as equation (4).

Substituting the entire equation (4) into the right-hand side of equation (3), the -th equation 2
When expanded and approximated with the entire left-hand side, the relationship of equation (5) is established.

IF' −×(e ten l@j, ([, I+l L, l
H) Ki X (e, L, H) + iθ・Δ63+1L−i
I, . . . (5) where ~, ffL are Jacobian matrices partially differentiated with respect to all 0 and 4 of X(O, IL, IH), respectively.

The Jacobian matrix is a matrix specific to the configuration of the robot, and its elements can be expressed by known mathematical formulas.

Suppose there is a point whose position is already known on the absolute coordinate system. This position is called the total calibration position.

The measurement reference point provided at the tip of the robot is moved to its calibration position, and the entire joint angle at that time is measured. In addition, by substituting the length of each arm, which was used as a control parameter during movement, and the position of the measurement reference point in the non-dot seat system into equation (5), three equations including unknown deviations Δe and 11L2 are obtained. To obtain equations for the number of unknown deviations, the posture of the tip of the robot is completely changed, and the measurement reference point is moved to the same calibration position for alignment. This operation is repeated multiple times, and 0 in each posture is measured and substituted into equation (5). Solving the simultaneous-order equations obtained above, Δ(iJ, *I,
I can claim it.

The error that occurs in the linear Taylor expansion approximation of equation (5) can be absorbed by repeating the process of adding ΔeknΔ obtained in the previous process to the kk original ek+lLk, and then repeating the process of adding j19+c+1r j I[Se1 to Tokyo. do.

Qj+r+-1=ak+jekr lLk+x=
(Lrk+l [,,=”・−−−−−・・71 Also, this iterative calculation stops when ΔOk and Δshik obtained in a certain process satisfy the preset convergence criteria, and then Let the sum of Δok and ΔlLk obtained in the process be Δe + i [L.

Δ0=ΣΔ−1Δold=ΣΔ−2・・・・・・・・・・・・
. . . (8) (2)) Embodiments of the Invention First, an overview of the entire robot and calibration system according to the present invention will be fully explained.

FIG. 1 shows an example of an articulated robot having all six degrees of freedom to which the present invention is applied, and FIG. 2 shows an explanatory diagram of the configuration of the degrees of freedom of the robot shown in FIG. In the figure, 1 is a reference plate, 2 and 3 are conical holes, 4 to 6 are rotational joints, and 7fx to 9 are flexion joints.

A robot with 6 degrees of freedom is in Cartesian coordinate space,
The robot has the advantage of being able to achieve full freedom of movement because it has three degrees of freedom in the position of the tip of the robot and three degrees of freedom in its posture (orientation). That is, the robot as shown in FIG. 1 can change the position of the tip of the robot by fully rotating and bending the rotary joints 4 to 6 and the bending joints 7 to 9 shown in FIG. 2. ! -Able to take various postures in a fixed position. The following explanation will be made on the assumption that the robot = i as shown in Figure 1, but the present invention is not necessarily limited to this. 1 or more degrees of freedom k fil] controllable, 4 or more degrees of freedom? The present invention can be similarly applied to any robot having the following functions.

A displacement detector, which will be described later, and a reference plate 1 that facilitates positioning are attached to the tip of the robot.

The center of this reference plate 1 is on the rotation center axis of the rotational joint 6, which is the sixth joint, and the conical hole 2 is formed at this position.

At a predetermined distance from the center of the enclosure,
A conical hole 3 is formed.

FIG. 3 shows an example of a displacement detector, and FIG. 4 shows an explanatory diagram of attaching a strain gauge to the displacement detector shown in FIG. 3. In the figure, 11 is a leaf spring assembly, 12 is a spherical contact, and 13 is a conical hole 2'E7' that is glued to the surface of the conical hole 3 during alignment.
is a cross spring, 14 and 15 are parallel leaf springs, and 16 is a strain gauge? represent.

A displacement detector capable of detecting the entire displacement of the robot tip in the
Consists of 1. This plate spring assembly 11 has a flat part 2
A pair of facing parallel plate springs 14 for detecting displacement in the X direction arranged perpendicularly to the x direction and displaceable in the The parallel plate spring 15 for detecting displacement in the X direction and the flat part? It is fully equipped with a cross spring 13 for detecting the degree in two directions, which is arranged perpendicularly in two directions and can be displaced in two directions. The spherical contact 12 is fixed to the center of the cross spring 13 via a support rod having a sufficiently higher rigidity than the leaf spring.

A strain gauge 16 is attached to each leaf spring, as shown in FIG. 4, for example. By constructing a complete bridge circuit for each leaf spring using the strain gauge 16, an output voltage corresponding to the displacement of the spherical contactor 12 in the x, y, . . . z directions can be obtained. This board) Kune + i [1 body 11; l
: is attached to an XYZ mechanical stage so that the spherical contact 12 can move in the x1y1z direction.

FIG. 5 is a block diagram of the robot control device and calibration device used in the embodiment of the present invention, FIG. 6 is a functional block diagram of the robot control program, and FIG. 7 is a functional block diagram of the calibration device control program. show. In FIG. 5, the reference numeral 1 corresponds to FIG. 1, and 11.12 corresponds to FIG. 3. 20 is a robot, 21 is a displacement detector, and 22 is an XYZ mechanical stage.

The main operation panel 30 is a device for an operator to give operation commands to the robot 20, and uses an operation panel consisting of a keyboard and a display. The teaching operation box 38 is a device for manually controlling the entire robot 20. The external storage unit 39 is a device that stores a series of robot operation data taught by the operator.
Magnetic tape, floppy disk, etc. are used as recording media.
− hard disks, etc. are generally used.

The central processing unit 31 is a device that processes all robot control programs in the robot control program storage device 33 via an interface bus 35, and processes commands from an operator through the main operation panel 30 or teaching operation box 38 to all robots 20. In order to execute, the servo control circuit 3
Go to 6. Target position signals, angular velocity signals, and other safety signals for each joint of the robot? Send. The numerical arithmetic processing unit 32 assists the central processing unit &31 and performs all operations such as addition, subtraction, multiplication, and division of floating point numbers, trigonometric functions, and inverse trigonometric function operations. Servo control circuit 36
is a device that receives commands from the central processing unit 31 and drives the robot 20 accordingly, and is a function generating circuit that fully controls the current and pressure necessary to drive the motor built into the robot 20. Or is there a delay in motor tracking due to disturbances that occur as the robot 20 moves? It consists of a closed-loop control circuit that performs feedback correction. When the robot 20 is positioned at a predetermined position and posture, the operator issues a command from the main operation panel 30 or the teaching operation box 38 to memorize the entire position. At this time, the joint angles of the robot are read from the rotation angle detection circuit 37, converted into a data format used for control performance, and then stored in the numerical data storage device 34.

The jWIJH device of the XYZ mechanical stage 22, that is, the calibration device, also has the same configuration as the upstream robot control device. Spherical contact 12 at the tip of displacement detector 21
The displacement is converted into voltage by the displacement detection circuit 41 and displayed by the koji position display circuit 40. Servo control circuit 42
, external storage device 44, main operation panel 45, central processing unit 46
, the numerical arithmetic processing device 47, and the teaching data storage device 49,
Each works similarly to that of the robot controller described above.

The position detection circuit 43 detects the position on the XYZ mechanical stage 22, and the calibration device control program storage device 48 is a device that stores the entire calibration device control program shown in FIG.

The robot system@j program includes an absolute coordinate system control section 51 and a calibration data transmission/reception section 52, as shown in FIG. The absolute coordinate system control unit 51 controls the rotation angle? Rotation angle detection unit 53 that performs all detection processing and joint coordinate system? A conversion unit 54 converts to an absolute coordinate system, a target position/attitude calculation unit 55 that calculates the entire target position and orientation of the robot tip, and a target angle transmission unit 56 that sends the entire target position to the servo control circuit 36.
It has a trajectory interpolation section 57 for interpolating the movement trajectory, a conversion section 58 for converting an absolute coordinate system to an all-joint coordinate system, and an angular velocity transmission section 59 for instructing the servo control circuit 36 to complete the angular velocity.

The calibration data transmitting/receiving section 52 connects to a teaching data transmitting section 60 that transmits all teaching data to the calibration device, and a deviation? What is the deviation receiving section 61 that receives? have.

The calibration device control program mainly includes an XYZ mechanical stage control section 65 and a robot coordinate system calibration section 66. The XYZ mechanical stage control unit 65 includes a position detection unit 67 using the position detection circuit 43, a target position calculation unit 68 that calculates the target position, and a target position? It includes a target position transmitter 69 that sends data to the servo control circuit 42, a trajectory interpolator 70 that interpolates the movement trajectory, and a fast reaction transmitter 71 that provides full speed instructions to the servo control circuit 42.

The robot coordinate system calibration unit 66 includes a calibration position calculation unit 72 that calculates a calibration position, a robot teaching data receiving unit 73 that receives all teaching data from the robot control device, and a simultaneous-order equation that generates all simultaneous-order equations related to deviation. native part 74
It also has a deviation calculation unit 75 that calculates the solution to the simultaneous equations, and a deviation transmission unit 76 that sends the calculated deviation to the entire robot control device.

For example, in the above device configuration, the robot coordinate system according to the present invention is calibrated as described below.

Figure 8 is a diagram to explain the origin state of the robot at the time of design and all errors after assembly, Figures 9 and 10 are diagrams to explain the measurement of the calibration position, and Figure 11 is a diagram of the reference plate. An explanatory diagram of displacement detection, FIG. 12 is an explanatory diagram of the 7th hour of simultaneous equations for calculating the deviation, and FIG. 13 is a 70-chart of the process for calculating the total deviation.

The origin state of the robot set at the time of design is as shown in FIG. 8 fa), for example. However, due to errors in the machining of the arm and errors in the attachment of the joints, it actually ends up as shown in FIG. 8(b)K.

Here, although it is not clear from the figure, the rotational joints 4.5.6 also have an error of Δθ1. Δθ4. There is Δθ6. Generally speaking, when a robot is controlled on a total absolute coordinate system, the desired position and orientation will be different from the actually reached position and orientation. Here, the error Δ0=(lθI+'θ2°Δθ9.
Δθ4. Δθ0. Δθ6 and the deviation of the four arm lengths, 1L = (ΔL1.ΔL, , iL, , Le4)T. In addition, in the present invention, it is also possible to measure only l19 or ΔIL, or if necessary, the deviation Δ[=(i xh) of the measurement reference position.

Δyh, 1zh) It is also possible to move to Tokyo. To calculate ΔIH, use equation (5) × (0, n, II()′ft1
Jacobian matrix °JH partially differentiated with respect to H and II (
All you have to do is add the product term.

First, a method for measuring the calibration position at which the entire robot tip should be aligned will be described. First, the XYz mechanical stage 22 is driven by the control device, and the entire spherical contact 12 on the displacement detector 21 can be aligned with the conical holes 2 and 3 formed in the reference plate 1 at the tip of the robot. Please pls and
Position the tip of the robot in a position where the posture can be changed in various ways. 2 in Figure 9, this position is point LP
It is indicated by (0). And, for convenience, I
A point on the X-axis of the absolute coordinate system. The absolute coordinate system is a coordinate system defined depending on the installation state of the robot base, and can be freely set according to the work environment. If the joint origin O8 of the rotary joint 4 is not on the set X-axis as shown in FIG. 1O, this can be dealt with by adding an offset angle φ in the figure when detecting the rotation angle of the full rotation joint 40. Next, the robot is driven to the previously positioned position of the spherical contact 12 by the entire robot controller, and the contact is fully inserted into the conical hole 2 of the reference plate l at the tip.

Although FIG. 11 shows the spherical contact 12 inserted into the conical hole 3, the same applies to the conical hole 2. If the position of the spherical contact member 12 is out of alignment with the position of the spherical contact member 11J inserted into the conical hole 2, the leaf spring assembly 11 will be distorted. While observing all the outputs of the displacement detection circuit 41, the operator drives the robot so that the output becomes zero, that is, the outputs of the strain gauges in each of the displacement directions of the leaf spring assembly 110X, Y, and Z become zero. and position it at zero. The position of the spherical contactor 12 is determined by position detection times '#!' with the coordinates of the XYZ mechanical stage 22 being one axis. r43yo pd [Measure and memorize. Let the value be 1r(o).

Next, after removing the spherical contact 12 from the entire conical hole 2 while being careful not to disturb the entire robot, as shown in FIG.
Rotate the rotary joint by angle α. This position 〃) is marked by the point ω in Fig. 9. To this position, X
The spherical contact 12 is inserted into the conical hole 2 at the tip of the YZ mechanical stage 22 and the driving robot. While observing the entire direction of the displacement detection circuit 41, the operator adjusts the XYZ mechanical stage 22 't-drive T so that the direction of the displacement becomes zero.
h, and the coordinate value when it becomes zero
Measure and store the value. Set the value as 1r0). In the same way, position the robot at one point in FIG.
Obtain the coordinates 1111 of . This will be the 1st meeting IP.

- is on the X axis, so 1) = (x (0), y (o), 2 (0)) y (0) = 0, and the values of the X component and the X component at calibration position II'''2? The two-component value z''r;c and the height to the center of the spherical contact 12 are measured in advance. In the present invention, even when z(0) is unknown, the deviation Δ0. I can request the joint angle data required for the soft stage movement described later. need to be increased.

Next, what is the joint angle required for the calibration calculation at the previously determined calibration position @ 1p (11)? The method of measurement will be described. The arm length C and the measurement reference position Bi in the hand kneeling system are also required as data for the stopping schedule, but II uses the design value as the initial value, and in the old case it was measured in advance.

The XYZ mechanical stage 22 is driven by the control device, and the entire spherical contact 12 is positioned at the previously stored position 1r(O). The robot is driven to this position by the total control device, and the contact is fully inserted into the conical hole 3 of the reference plate 1 at the tip. If the leaf spring assembly 11 is distorted, while observing all outputs of the displacement detection circuit 41, drive the robot fully so that the output becomes zero, and detect the joint angle of the robot when the output becomes zero by using the rotation angle detection circuit 37. is detected and stored in the teaching data storage device 3.4.

Its value is set to 0 (1).

Next, the command is given to change only the posture of the tip of the robot, and the entire robot is driven. If there is a deviation from the actual value in the joint origin and arm length, even if a command to change only the posture is given, the conical hole 3
The position of is displaced and the leaf spring assembly 11 is distorted. Therefore, as described above, the robot is driven so that the displacement of each leaf spring becomes zero, and the joint angle of the robot when the displacement becomes zero is calculated. Above that value. Repeat this measurement two more times by changing the posture of the tip of all robots, and measure the joint angles in a total of 4 postures.
obtain.

As can be seen from equation (5) above, the calibration position, r(o)
If all the xp Y r z components of are known, 12 equations can be obtained with four sets of joint angle data. Unknown deviation is Δ0
=(lθ1.)θtr'θ8.ノθ4. Δθ5)pal
L=(ΔL1., iL, .

Since there are 10 equations of Δ”s l KL4 ), it is only necessary to calculate the unknown deviation by performing all 10 regressions from the 12 equations.

1lH=(ax,,jy,,)z,) If it is calculated by 1, then 1
Since three equations are required, five sets of joint angle data are required. Also, if the two components are unknown, the two-component term cannot be used in the equation (5), so ie, iIl, 5 sets if required, 70 * ' L r ' [7 if US The joint angle data of the set is reliable.

V(o), @(”), (jo
@(S), 63° When substituted into equation (5), it becomes as follows.

Here, 'eid is a 3x6 matrix and KL is a 3x4 matrix.

Select 10 equations from these 12 equations and generate all simultaneous -order equations of the form 1Mx=+n. This simultaneous-order equation is
The shape will be as shown in FIG. M is a 10×10 regular matrix, 1 is a 10-dimensional constant vector, and X is a 10-dimensional solution vector.

All of these simultaneous-order equations are solved using well-known algorithms such as the so-called cloud method and sweep method. However, the 9th
This is an equation approximated by a first-order Taylor expansion, and the deviation that is usually desirable in one operation is r19. j [L cannot go to Tokyo. Therefore, the operation amount shown in the 70-chart of FIG. 13 is repeated. In other words, as shown in FIG.
It stopped when the norm l jOkl+1ΔLk+ of tLIk became smaller than the set minimal value ε, and at that point 1 was obtained. iek, total sum of ΔILk, Δe, iL to seek
shall be.

Δθ,, = ΣΔθlj (t = 1 to 6) j = 1 iL, = Σ1LIj (l = 1 to 4) j = 1 The determined deviation i6j of the joint origin is set in the control program storage device, and all joint angles are detected. Addition and subtraction are performed when the target joint angle is sent to the servo control circuit.

In addition to the design value IL, the arm length deviation Δ is reset to the arm length in the control program storage device.

Finally, a method for evaluating a robot calibrated according to the present invention will be described. The robot tip 1 moves repeatedly on the absolute coordinate system within the drive range of the XYZ mechanical stage 22. The conical hole 3 and the spherical contact 12 are then completely aligned using the method previously described. By completely comparing the commanded moving distance of the mouth pot tip with the actual moving distance measured by the XYZ mechanical stage 22, it can be determined whether or not the calibration has been performed to the desired accuracy. Also, as another method, the conical hole 3 and the spherical contact 12 are aligned, and then a command is issued to change only the posture from that state? give. And then, after observing all the output of the strain gauge at that time, what about the XYZ mechanical stage? The calibrated accuracy is fully evaluated by driving and measuring the displacement (positional deviation) at the point where the strain becomes zero.

In this example, to measure the three-dimensional position of the robot's tip, a reference plate with a conical hole is used, and a spherical contactor is mounted on an XYZ mechanical stage. Although a device with a flat spring assembly attached thereto was used, the device used in the present invention is not limited to this, and any device can be used as long as it can three-dimensionally measure the position to be measured at the tip of the robot. It can be anything.

2. When a robot performs actual work, a hand is usually used for assembly work, and a spray gun is used for welding and painting work, but when an object-affecting body suitable for these purposes is attached to the tip of the robot. , the control reference position of the effector 1jl
It is sufficient to measure it in the t'lk hand coordinate system and set it as 2 and H.

(F) Detailed Description of the Invention As described above, the present invention allows relatively easy operation, and after robot assembly is completed, joint installation is performed to determine errors and arm length deviations, and the robot's reference system? Calibration and high absolute accuracy? Obtainable.

[Brief explanation of the drawing]

Fig. 1 is an example of an articulated robot having six degrees of freedom to which the present invention is applied, Fig. 2 is an explanatory diagram of the configuration of the degrees of freedom of the robot shown in Fig. 1, and Fig. 3 is an example of a displacement detector. Figure 4 is an explanatory diagram of attaching the strain gauge to the displacement detector shown in Figure 3, Figure 5 is a block diagram of the robot control device and calibration device used in the embodiment of the present invention, and Figure 6 is the function of the robot control program. Block diagram, Figure 7 is a functional block diagram of the combat equipment control program, Figure 8 is a diagram to clarify the origin state of the robot at the time of design and the error basin after assembly, Figures 9 and 10 are calibration diagrams. Figure 11 is an explanatory diagram for detecting the displacement of the reference plate, and Figure 12 is a diagram for explaining the entire measurement of position. FIG. 13 is an explanatory diagram of the simultaneous order equations to be calculated, and a flowchart for the process of calculating the deviation. In the figure, 1 is a reference plate, 2 and 3 are conical holes, 11 is a leaf spring assembly, 12 is a spherical contact, 16 is a strain gauge, 20 is a robot, 21 is a displacement detector, and 22 is an entire XYZ mechanical stage. . Patent Applicant Fujitsu Ltd. Representative Patent Attorney Hiru 1) Hiroshi (1 other person)? C illustration, 17m

Claims (1)

[Claims] An arm-shaped robot having all of a plurality of joints, a control means for driving the tip of the robot on an orthogonal coordinate system, and a rotation angle detection means for detecting the rotation angle of the joint provided at each joint of the robot. , its detected rotation angle? In a system comprising a storage means for storing information, and a displacement detection means for detecting displacement in x, y, and z directions when the robot tip fully moves on a Cartesian coordinate system, at least one The process of measuring all the calibration positions and the tip of the robot in the above calibration position? The process of positioning to form a plurality of postures, detecting and storing all the rotation angles of the valley thoracic segment at j=' in each posture, and the rotation angles of the plurality of joints stored above and the arm at the time of design. Based on the length, the process of determining the error in the installation of the robot's valley joint during assembly and the deviation of the arm length during manufacturing;
The installation of each of the joints is a process in which the actual origin position obtained from the error and the actual size of the arm obtained from the arm length deviation are reflected in the coordinate conversion process in the control means of the robot, and the calibration results are fully evaluated. A method for calibrating a robot coordinate system that has all the characteristics of meeting with the robot.