JP3121978B2 - Minimum time positioning control method and device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shortest time positioning control method and apparatus in which, for example, a multi-axis robot arm is started from a predetermined position, moves along a predetermined path, and stops at a predetermined position.

[0002]

2. Description of the Related Art Conventionally, in remote control of a machine tool, a tool is moved to a predetermined path by a method of adjusting a pulse density applied to a step motor of each axis.

[0003]

In such a method,
It is excellent when moving a predetermined route with high accuracy, but cannot guarantee the accuracy when moving at a high speed. In addition, in the case of a large machine tool, high-speed movement becomes impossible due to the limitation of the electric motor capacity.

An object of the present invention is to control the speed by using a DC motor, an AC motor, or the like at the maximum performance, that is, at the maximum acceleration / deceleration torque, the maximum speed, and the like, to minimize the time required for various moving routes. Another object of the present invention is to provide a control method for performing high-accuracy positioning.

It is another object of the present invention to provide a shortest-time positioning control device for implementing such a control method.

[0006]

In order to achieve the above object, a shortest time positioning control method according to the present invention provides a shortest time acceleration and a maximum speed of a motor of a longest axis to a starting position and a middle point of a predetermined moving path. Driving, the other motor follows it, and the longest axis motor from the midpoint to the stop position is decelerated at the maximum speed and the shortest time, and the other motors follow the predetermined path for the shortest time and It is characterized by moving with high precision.

Further, the shortest time positioning control device of the present invention comprises: a moving path setting means for setting a moving path; a midpoint setting means for determining midpoint coordinates of the set moving path;
Positioning is advanced by the speed command for maximizing torque acceleration and maximum speed operation of the motor of the largest axis among the axis moving distances of the difference between each axis coordinate of the determined middle point and the starting coordinate, and the other axes follow it. Means for moving a predetermined path according to a speed command to be performed, and positioning by a speed command for performing a maximum speed and a maximum torque deceleration operation of the motor of the largest axis among the axis movement distances of the difference between the stop coordinates and the midpoint coordinates of each axis And the other axis is provided with means for moving a predetermined path according to a speed command following the other axis.

[0008]

By using the moving path setting means and the midpoint coordinate determining means, the motor having the longest axis up to the start position and the midpoint position is
The motor of the axis is accelerated and operated at the maximum speed for the shortest time by the maximum speed command generating means, and the motor of the other axis follows this, thereby moving along a predetermined path to advance the positioning.

Next, the motor of the longest axis up to the midpoint position and the stop position is decelerated at the maximum speed and the shortest time by the maximum speed command generating means, and the motors of the other axes follow this. Thereby, the positioning is advanced by moving along a predetermined path.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of a shortest time positioning control method and apparatus according to the present invention.

FIG. 1 is a block diagram of one embodiment of a shortest time positioning control device. The shortest time positioning control device includes a moving path setting means 1, a midpoint coordinate determining means 2, a maximum moving axis specifying means 3, an X-axis maximum speed command generating means 4, an X-axis speed adjusting means 5, an X-axis electric motor 6, Axis position moving mechanism 7,
Y-axis following speed command generating means 8, Y-axis speed adjusting means 9, Y
It comprises a shaft motor 10, a Y-axis position moving mechanism 11, an XY path moving mechanism 12, a Y-axis maximum speed command generating means 13, and an X-axis following speed command generating means 14.

Each means may be realized by using an electronic circuit, or may be realized by a computer.

The operation of this embodiment will be further described with reference to FIGS. 2, 3 and 4. FIG. 2 is a movement path diagram, FIG. 3 is a relationship diagram of the X-axis motor speed and position with respect to time, and FIG. 4 is a relationship diagram of the Y-axis motor speed and position with respect to time.

[0014] As initially shown in Figure 2, the moving path 0AB is provided on a plane made of X-axis position P _X and Y-axis position P _Y, it is set to travel route setting section 1 in FIG. 1.

Now, it is assumed that this movement route is given by equation (1).

[0016]

(Equation 1)

That is, it is assumed that a monotonically increasing moving path is provided.

Next, the midpoint coordinate determining means 2 in FIG.
Using the equation (1), the coordinates (P _XN , P _YN ) of the midpoint A are determined by the equations (2) to (4).

[0019]

(Equation 2)

In this case, equation (5) holds.

[0021]

(Equation 3)

Therefore, the maximum movement axis designating means 3 shown in FIG.
The X-axis is designated by and is given to the X-axis maximum speed command generation means 4.

The X-axis maximum speed command generating means 4 generates a speed command n _XA during a period of time t ≦ t ≦ t ₂ in FIG.
This is given to the X-axis speed adjusting means 5 in FIG. 1, and the positioning is advanced as shown by the position p _XA in FIG.

In this case, at each time t, a speed command n _XA is given from the X-axis speed command generating means 4 to the Y-axis follow-up command generating means 8 in FIG. In the Y-axis following speed generating means 8,
The time t is divided into 0 ≦ t ≦ t ₁ and t ₁ ≦ t ≦ t ₂ , and a Y-axis following speed command n _YA is generated using Expression (6).

[0025]

(Equation 4)

The Y-axis follow-up speed command n _YA in the equation (6) is shown in FIG.
The Y-axis speed adjusting means 9 is used to advance the positioning as shown by a position p _YA in FIG. The actual position is given by the XY path moving mechanism 12 as a vector sum of the X-axis position p _XA and the Y-axis position p _YA , and is moved and positioned along the movement path OA shown in FIG.

Next, the coordinates (p _XN , p _YN ) of the middle point A in FIG.
The movement of the route between the coordinates of the final position B (p _XM , p _YM ) will be described. In this case, equation (7) holds.

[0028]

(Equation 5)

Therefore, in this case, the Y-axis is designated by the maximum movement axis designation means 3 and given to the Y-axis maximum speed command generation means 13.

[0030] In the Y-axis maximum speed command unit 13, the time t in FIG. 4, to generate a speed command n _YB a period of t ₂ ≦ t ≦ t _4, giving it to the Y-axis speed adjusting means 9, the motor 10 As a result, the positioning is advanced as shown by the position p _YB in FIG.

In this case, at each time t, a speed command n _YB is given from the Y-axis speed command generating means 13 to the X-axis following speed generating means 14. In the X-axis following speed generating means 14,
The time t is divided into t ₂ ≦ t ≦ t ₃ and t ₃ ≦ t ≦ t ₄ , and an X-axis following speed command n _XB is generated using Expression (8).

[0032]

(Equation 6)

The speed command n _XB in the equation (8) is given to the X-axis speed adjusting means 5, and the electric motor 6 advances the positioning as shown by the position P _XB in FIG. . The actual position is given by the XY path moving mechanism 12 as a vector sum of the Y-axis position P _YB and the X-axis position P _XB , and is moved and positioned along the movement path AB shown in FIG.

However, when positioning is performed by each arm joint drive motor like a robot arm, the XY path moving mechanism 12 in FIG. 1 does not always need to be used.

As described above, as an embodiment, two axes of the X axis and the Y axis are used.
The method of controlling the positioning of the axes has been described. However, it is clear that the present invention can be easily extended to multi-axes of three or more axes, and the description is omitted.

Although the embodiment has been described with reference to the case where the moving route is monotonically increasing, the present invention can be extended to a case of monotonically decreasing and a plurality of combinations of monotonically increasing or monotonically decreasing.

[0037]

According to the present invention, the motor of each axis is accelerated / decelerated with the maximum torque and is operated at the maximum speed with respect to the given moving path, so that the positioning can be performed in the shortest time.

Further, for example, by processing each means shown in FIG. 1 by using a computer, there is an effect that very high-precision positioning with respect to the moving path can be realized.

There is an effect that positioning can be performed with high accuracy and in the shortest time even for a moving path in which a plurality of moving paths that monotonically increase or decrease are combined.

Further, since the utilization efficiency of the motor rating is good, there is an economic effect that a motor having a required minimum capacity can be used.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a movement route diagram.

FIG. 3 is a diagram showing the relationship between the motor speed and the position of the X-axis with respect to time.

FIG. 4 is a diagram showing the relationship between the motor speed and the position of the Y axis with respect to time.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 moving path setting means 2 midpoint coordinate determining means 3 maximum moving axis specifying means 4 X-axis maximum speed command generating means 5 X-axis speed adjusting means 6 X-axis motor 7 X-axis position moving mechanism 8 Y-axis following speed command generating means 9 Y-axis speed adjusting means 10 Y-axis motor 11 Y-axis position moving mechanism 12 XY path moving mechanism 13 Y-axis maximum speed command generating means 14 X-axis following speed command generating means

Claims (3)

(57) [Claims] When a positioning is performed by moving a predetermined path that monotonically increases or decreases by using a motor of each axis, a speed command generating means, a means for adjusting the motor speed by the command, and a position by the motor. The means for moving is a unit axis position moving system, the system is used as a required unit, and a shortest time positioning control method of a positioning control device configured by a predetermined moving path setting means and a middle point coordinate determining means comprises: Of each axis coordinate of the point and the axis movement distance of the difference between the starting coordinate, the positioning is advanced by the speed command for maximum torque acceleration and maximum speed operation of the motor of the largest axis, and the other axis is driven by the following speed command. By moving the predetermined path, the motor of the largest axis among the axis movement distances of the difference between the stop coordinates and the middle point coordinates of each axis is set to the maximum speed and A shortest time movement path positioning control method, characterized in that positioning is advanced by a speed command for a maximum torque deceleration operation, and another axis is moved on a predetermined path by a speed command following the speed command. 2. A method according to claim 1, wherein a predetermined path that monotonously increases or decreases is used as a unit, and when the path is moved and positioned by combining a plurality of units, a predetermined combination of the positioning control methods according to claim 1 is used. A shortest moving path positioning control method, characterized in that a moving path is moved. 3. A shortest time positioning control device for moving and positioning a predetermined path that monotonically increases or decreases by using a motor of each axis, a moving path setting means for setting a moving path, Coordinates determining means for determining the midpoint coordinates of the moving path, the axis coordinates of the determined midpoint, and the axis of the difference between the starting coordinates and the axis movement distance, the motor of the largest axis is subjected to the maximum torque acceleration and Means for moving the predetermined path by the speed command following the speed command while following the speed command to perform the maximum speed operation, and of the axis movement distance of the difference between the stop coordinates and the midpoint coordinates of each axis,
Means for moving the motor of the largest axis by a speed command for a maximum speed and a maximum torque deceleration operation, and for moving the other axis along a predetermined path by a speed command following the same. Path positioning control device.