JPH054181A - Robot control device - Google Patents

Abstract

PURPOSE:To conform the robot control device to a change to any given axial construction by making combination of coordinate transformation matrices on the basis of the data collected by an axis construction discrimination means to calculate each joint angular velocity, etc., of the manipulator for each point of passage. CONSTITUTION:A manipulator 1 is constructed of connections mad of given arm joint modules 2a, 2b,...2h. Each arm joint module is equipped with a motor for driving its axial shaft and with a controller 3a, 3b,... or 3h for controlling operation. The robot control device has coordinate transformation matrices for various axis-type arm joint modules and makes combination of these matrices on the basis of the constructional data of the manipulator 1 discriminated by an axis construction discrimination means 7 to calculate an amount of change in each joint angle which is necessary for a terminal effector 2h of the manipulator 1 to move up to a next passage point, i.e., a position up to which it is to move by the next sampling time, in regard to each passage point determined by a trajectory calculation function 8 thus to send it to each controller.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a robot controller capable of changing to any type of axis in a manipulator, for example.

[0002]

2. Description of the Related Art In robot control, one dedicated control program is created for each robot. Then, if the robot configuration, for example, the axis of the manipulator is changed, a new control program is created for the robot having the changed axis configuration. Further, when operating the robot using the same robot control method, if the configuration of the robot is different, it is necessary to change the program content of the interpolation calculation for obtaining each speed of each joint of the manipulator.

Therefore, recreating the programming each time the robot configuration is changed is time-consuming, costly, and very inefficient. However, although the robot has general versatility in terms of operation contents,
For a target work, a robot having a specific configuration for that work must be assembled. Furthermore, the robot has to change the contents of the control program every time the configuration is changed, which is not very versatile and expandable, which is very inefficient.

[0004]

As described above, the contents of the control program have to be changed every time the configuration of the robot is changed, which is not very versatile and expandable, and is very inefficient. Therefore, an object of the present invention is to provide a robot control device that can easily create a corresponding control program even if the axis configuration is changed to any desired axis configuration and that improves efficiency.

[0005]

SUMMARY OF THE INVENTION The present invention is directed to a plurality of arm joint modules having axes of various types of joints and a controller for driving and controlling the axes and storing data such as the type of the axes, and the arm joint modules. Of the manipulators that connect the desired arm joint modules among the manipulators to discriminate the manipulator configuration, and the arm joint modules of the manipulator from the current position of the effector to the target movement position. Trajectory calculating means for determining each passing point and coordinate conversion matrices for various axis types are combined, and coordinate conversion matrices are combined based on the data collected by the axis configuration determining means to calculate each joint angular velocity of the manipulator for each passing point. A robot control apparatus, which is provided with an interpolating calculation means for calculating and tries to achieve the above object.

[0006]

By providing such means, the axis configuration determining means collects data from each controller of the manipulator in which desired arm joint modules among the respective arm joint modules are connected to determine the configuration of the manipulator. Further, the trajectory calculation means obtains each passage point from the current position of the effector to the movement target position in each arm joint module of the manipulator, and the interpolation calculation means combines the coordinate conversion matrix based on the data to obtain each passage point. Calculate each joint angular velocity of the manipulator for each.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of a robot controller.
The manipulator 1 is an arbitrary arm joint module 2a, 2
b, ... 2h are connected. The arm joint modules 2a, 2b, ... 2h will be described. First, the arm joint modules 2b, 2d, 2g have a rotary type “1” type shaft shown in FIG. 2 and rotate in the arrow (a) direction. .. It should be noted that in each of the drawings showing the arm joint modules 2a, 2b, ... 2h, an external view of the arm joint modules 2b, 2d, 2g is shown together with its basic element symbols. Next, the arm joint modules 2a, 2e and 2f have a rotary type "2" type shaft shown in FIG.
Rotate in the direction. Next, the arm joint module 2c is shown in FIG.
It has a slide type shaft as shown in and slides in the direction of arrow (c). Next, the arm joint module 2h is the hand effector shown in FIG. 5, and grips in the arrow (d) direction. The original arm joint module 2a of the manipulator 1 is connected to the base module 2i. The base module 2i has xyz coordinate axes defined, and each arm joint module 2a, 2b, ...
When h is connected, these arm joint modules 2a, 2
The joint axes of b, ... 2h are always xy of the base module 2i.
It is configured to coincide with any of the z coordinate axes.

These arm joint modules 2a, 2b,
... 2h includes motors for driving the respective shafts and respective controllers 3a for controlling these motors,
3b, ... 3h. These controllers 3a,
.. 3h has a communication control program and a motor control program as shown in FIG. 6, and each controller 3a,
3h and communication control functions 5a, 5b, ... 5h for exchanging data with the host computer 4 and motor control functions 6a, 6b, ... 6h for driving and controlling the motor based on the received data. is doing. In addition, the respective types of axes of the respective controllers 3a, 3b, ... 3h, that is, the rotary type “1” and “2” shown in FIGS. There is.

The host computer 4 has an axis configuration determination program, a trajectory calculation program, an interpolation calculation program, and a communication control program. By executing these programs, the axis configuration determination function 7 and the trajectory calculation function as shown in FIG. 8, an interpolation calculation function 9 and a communication control function 10.

The axis configuration discriminating function 7 collects data registered in the controllers 3a, 3b, ... 3h of the manipulator 1 in which desired arm joint modules 2a, 2b ,. It has a function to discriminate.

The trajectory calculation function 8 is an effector 2 of the arm joint modules 2a, 2b, ... 2h of the manipulator 1.
It has a function of obtaining each passing point from the current position of h to the movement target position for each sampling time.

The interpolation calculation function 9 has a coordinate conversion matrix for arm joint modules of various axis types, and calculates a trajectory by combining coordinate conversion matrices based on the data of the configuration of the manipulator 1 discriminated by the axis configuration discrimination function 7. For each passing point obtained by the function 8, the change amount of each joint angle required for the hand effector 2h of the manipulator 1 to move to the next passing point, that is, the position to be moved by the next sampling time is calculated. It has a function of sending to each controller of the manipulator. Specifically, the interpolation calculation function 9 creates a Jacobian matrix J by combining coordinate conversion matrices of various types of axes based on the configuration of the manipulator 1. This Jacobian matrix J is the vector [dx
/ dt, dy / dt, dz / dt], the rotational velocity of the posture around the coordinate system defined by the hand effector 2h is a vector [dφ / dt, dθ / dt, dψ / dt], and the angular velocity of each joint. Is a vector θa, θb, ... θh, the following relation

[0014]

[Equation 1]

It is represented by 0. Next, interpolation calculation function 9
Solves the inverse Jacobian matrix J ⁻¹ of the Jacobian matrix J and calculates the joint change speed from the moving speed of the hand effector 2h of the manipulator 1 from the following equation.

[0016]

[Equation 2] Next, the interpolation calculation function 9 determines the required joint angular velocities θa, θb,
.. .theta.h is sent to each of the controllers 3a, 3b ,.

Here, a method of creating the Jacobian matrix J will be described. The coordinate system of the manipulator arm is defined in the initial state as shown in FIG. Next, a coordinate transformation matrix is set for each joint of the manipulator arm. If the unique coordinate transformation matrix corresponding to the i-th joint is Ti,

[0018]

[Equation 3]

It becomes In these matrices, equation (3) is x
When rotating around the i-axis, the equation (4) rotates around the yi axis, and when the equation (5) rotates around the zi axis,
If equation (6) slides in the xi-axis direction, equation (7) yields y
When sliding in the i-axis direction, Equation (8) shows a case in which the sliding is performed in the zi-axis direction. Also, in these equations, cθi = cosθi and sθi = sinθi.

Θi is a rotation angle in the case of a rotary joint and a movement amount in the case of a slide joint. mx (i), my
(I) and mz (i) are movement amounts in the xi, yi, and zi axis directions required to move from the i-th joint to the (i + 1) th joint. The Jacobian matrix J is obtained by the following formula.

[0021]

[Equation 4] If the i-th joint is a slide type, change the i-th column of the Jacobi matrix J

[0022]

[Equation 5] Instead of.

Where the vector ⁰ S _i is the rotation axis direction of the i-th joint as seen from the base coordinate system x0, y0, z0 in the case of a rotary joint as shown in FIG. 11, and the unit vector in the slide direction in the case of a slide joint as shown in FIG. And
Also, the vector ⁰ P _i is the position vector from the base coordinate origin to the i-th joint as shown in FIG. vector ⁰ S _i , ⁰ P _i is obtained as an element of a 4 × 4 matrix obtained by Ri = T1 T2 ... Ti.

[0024]

[Equation 6] It is assumed that the vector S _i matches the axis of the joint among the vectors S xi, Syi, and S zi.

With this structure, the operator selects and connects the desired arm joint modules 2a, 2b, ..., 2h, and thereby the manipulator 1 shown in FIG.
2h, the axis configuration determining function 7 of the host computer 4 collects each data registered in each controller 3a, 3b, ... 3h of each arm joint module 2a, 2b ,. These data are the types of shafts as described above, that is, the shaft types and dimensions of the rotary type "1" and "2", the slide type, the hand effector, etc. shown in FIGS. When the axis configuration determination function 7 collects each data, the reference symbols p0, p1, ... From the base module 2i toward the hand effector 2h.
Then, the number of axes n, the type of each axis, and the axis of the joint (the rotary axis in the case of the rotary type, the axis in the moving direction in the case of the slide type) are determined. Next, in the manipulator 1 having the initial configuration, the axis configuration determining function 7 moves the amounts mx (i), my for moving from, for example, the kth joint to the (k + 1) th joint as shown in FIG.
(I) and mz (i) are obtained.

Next, the trajectory calculating function 8 obtains each passing point s1, s2, s3 ... From the current position s0 of the hand effector 2h of the manipulator 1 to the movement target position sn as shown in FIG. 8 at each sampling time. .. For example, in the figure, the distance w1 between the passing points s3 and s4 and the distance w2 between s4 and s5 respectively indicate the movement amount of the hand effector 2h within the sampling time.

Next, the interpolation calculation function 9 executes the interpolation calculation according to the interpolation calculation flow chart shown in FIG. That is, the interpolation calculation function 9 receives each data collected by the axis configuration determination function 7 in step f1, and in the next step f2, each passing point s1, s2 from the current position s0 of the hand effector 2h to the movement target position sn, s3 ... and its posture. Next, the interpolation calculation function 9 obtains the current position of the end effector 2h, for example, the position at that time if the end effector 2h is moving in step f3. Next, the interpolation calculation function 9 combines the coordinate conversion matrices of each axis type based on each data collected by the axis configuration determination function 7 in step f4 to create the Jacobian matrix J shown in equation (1), and then in step f5 In, the inverse Jacobian matrix shown in equation (2) is created and calculated. Next, the interpolation calculation function 9 obtains the required joint angular velocities θa, θb, ... θh at step f6, and at the next step f7 the joint angular velocities θa, θb, ...
3b, ... 3h. Note that each of these joint angular velocities θ
If a, θb, ..., θh are values obtained at the passing point s3, for example, they are angular velocities for moving to the next passing point s4. However, the interpolation calculation function 9 determines that each passing point s
.. θ for each joint angular velocity θa, θb, ...
Find h.

As described above, in the above embodiment, the controllers 3a, 3b, ... 3 of the manipulator 1 formed by connecting the desired arm joint modules 2a, 2b ,.
The data is collected from h to determine the configuration of the manipulator 1, and the current position s0 of the hand effector 2h of the manipulator 1 is determined.
To the moving target position sn from each passing point s1, s2, s3
... is calculated, and the angular velocities of the joints of the manipulator 1 for each of these passing points s1, s2, s3 are calculated to calculate the manipulator 1
.. 3h, the movement of the manipulator can be controlled without creating a new control program for the changed manipulator even if the axis of the arm joint module constituting the manipulator is changed. .. As a result, a manipulator of any axis can be constructed, and the manipulator can be immediately moved and controlled. Therefore, versatility and expandability can be dramatically improved.

The present invention is not limited to the above-mentioned embodiment, but may be modified within the scope of the invention. For example, the arm joint module may use a module not described in the above embodiment.

[0030]

As described above in detail, according to the present invention, it is possible to provide a robot control device having an improved efficiency because a corresponding control program can be easily created even if the axis configuration is changed.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of a robot controller according to the present invention.

FIG. 2 is an external view of a rotary type “1” arm joint module in the same apparatus.

FIG. 3 is an external view of a rotary type “2” arm joint module in the device.

FIG. 4 is an external view of a slide type arm joint module in the device.

FIG. 5 is an external view of an arm joint module of a hand effector in the device.

FIG. 6 is a functional block diagram of a host computer and each controller in the same apparatus.

FIG. 7 is a schematic diagram showing a movement amount in the manipulator initial state in the same apparatus.

FIG. 8 is a view showing a passing point of a hand effector of a manipulator in the device.

FIG. 9 is a flow chart of interpolation calculation in the same apparatus.

FIG. 10 is a schematic diagram showing a coordinate system of a manipulator arm.

FIG. 11: i-th view from the base coordinate system in a rotary joint
The figure which shows the rotating shaft direction of a joint.

FIG. 12 is a schematic diagram showing a slide direction in a slide joint.

FIG. 13 is a diagram showing a position vector from the base coordinate origin to the i-th joint.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Manipulator, 2a-2h ... Arm joint module, 3a-3h ... Controller, 4 ... Host computer, 7 ... Axis configuration determination function, 8 ... Orbit calculation function, 9 ... Interpolation calculation function, 10 ... Communication control function.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location G05B 19/403 P 9064-3H 19/415 Z 9064-3H

Claims (1)

Claims: 1. A plurality of arm joint modules having axes of various types of joints and a controller for driving and controlling the axes and storing data such as the types of the axes,
Of these arm joint modules, a shaft configuration discriminating means for discriminating the configuration of the manipulator by collecting the data of the manipulator, which is formed by connecting desired arm joint modules, and the present effector of the arm joint modules of the manipulator. Trajectory calculating means for obtaining each passing point from the position to the movement target position, and coordinate conversion matrices for the various axis types, and combining the coordinate conversion matrices based on the data collected by the axis configuration determining means A robot controller, comprising: interpolation calculation means for calculating each joint angular velocity of the manipulator for each passing point.