JPH0433012A - Velocity controller - Google Patents

Abstract

PURPOSE:To shorten a time required for movement by calculating a linear path satisfying the limit condition of a driving system or the maximum velocity and maximum acceleration of each driving shaft for each command unit of the path, and executing control by using those results of the calculation. CONSTITUTION:A velocity calculation part 10 is provided to calculate the maximum path velocity based on a path command value and each shaft maximum allowable velocity set in advance, and an acceleration calculation part 11 is provided to calculate the maximum path acceleration based on the path command value and each shaft maximum allowable acceleration set in advance. Further, an acceleration/deceleration processing part 3 is provided to accelerate/ decelerate the calculated maximum path velocity based on the calculated maximum path acceleration, and a velocity distribution part 4 is provided to distribute the accelerated/decelerated maximum path velocity to the velocity in each axial direction. Then, the control is executed at the maximum velocity or acceleration to satisfy the allowable limit value of each driving shaft. Thus, the velocity controller can be obtained to be easily programmed and to be moved in the path at high speed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a speed control device for driving a tool of a machine tool or a hand of a robot at high speed along a movement path.

[Conventional technology] In numerical control devices that control machines with multiple drive axes, such as machine tools and robots, when moving a tool or hand along a straight path, servo commands are sent to satisfy pre-given speeds and accelerations. A method is adopted in which the speed waveform of the value is controlled and driven.

Conventionally, this type of technology includes, for example, Japanese Patent Application Laid-Open No. 63-146.
There is a speed control device disclosed in Japanese Patent No. 105, the configuration of which is shown in FIG. In the figure, (1) is an input section for inputting a command value for a moving route, (2) is a speed signal generating section for generating a moving speed signal for the route based on the input value, and (3) is a speed signal generating section for generating a moving speed signal for the route based on the input value.
) is an acceleration/deceleration processing unit that accelerates or decelerates the output speed of the speed signal generator (2) at a predetermined constant acceleration, and (4) decomposes the accelerated or decelerated speed into each axis component of each drive shaft. This is a speed distribution section that outputs the

In the device configured in this way, the X-
The operation when moving along the straight path 1 (5) on the Y plane will be described with reference to the operation waveforms of each component shown in FIGS. 9(a) to 9(d). First, the input unit (1) inputs the amount of movement (X.

Enter the values of Y) and moving speed F. Speed signal generator (2
) is a step-like speed signal S(
FIG. 9(a)) is generated, and the time [T corresponds to the time (T=L/F) for moving at the speed F of 11-j%L (L=X+Y). Acceleration/deceleration processing section (3)
shapes the rising and falling edges of this step-like speed signal S, and outputs a speed signal (2) (FIG. 9(b)) having a speed change of a preset constant acceleration. Speed distribution section (
4) Using the route command values (X, Y) and the route length, calculate the X-axis component VX and Y-axis component vY of this speed signal ■ output from the acceleration/deceleration processing unit (3) using the following formula. and outputs it as a speed command signal for each axis (Fig. 9(C)).

(d)).

X Y vx=-・ v -vY=-・ ■ L L This series of operations is executed for each command unit of the route, and when the movement of route 1 (5) is completed, the operation of the next route 2 (δ) is started. Move.

On the other hand, in the drive system of each axis (not shown here), there is a limit to the speed and acceleration that can follow the command depending on the power of the drive motor, the inertia and load of the driven mechanical axis, etc. The command value VX of each axis is set so as not to exceed the maximum allowable speed and maximum allowable acceleration.
It is necessary to create VY. Normally, for speed, the command value is created by considering constraints at the program stage, and for acceleration, the value set in the acceleration/deceleration processing section (3) is generally selected as the minimum value of the maximum allowable acceleration of each drive axis. Futa.

[Problem to be solved by the invention]

As mentioned above, with conventional speed control devices, it is necessary to give command values in advance by considering the maximum allowable speed constraints of each axis, which makes programming cumbersome and does not necessarily provide optimal values. As for acceleration, the minimum value of the maximum permissible acceleration of each axis is set as a fixed value, and acceleration/deceleration processing is performed using this value, so the time required for movement becomes longer and the rice is not harvested due to high speed. There was a problem.

This invention was made in order to solve the above-mentioned problems, and it is possible to control each drive shaft at the maximum speed or acceleration that satisfies the allowable limit value, and to easily program and enable high-speed path movement. The purpose is to obtain a speed control device that

[Means to solve the problem]

The speed-side AT device according to the present invention calculates the shaft speed command of each drive shaft based on the path command value consisting of the travel amount and travel speed of each drive shaft for moving the moving body along a fixed path. , in what is output to the control section, a speed calculation section that calculates the maximum path speed based on the above-mentioned path command value and the preset maximum allowable speed of each axis, and a speed calculation section that calculates the maximum path speed based on the above-mentioned path command value and the preset maximum allowable acceleration of each axis. an acceleration calculation unit that calculates a maximum path acceleration based on the calculated maximum path acceleration; an acceleration/deceleration processing unit that accelerates or decelerates the calculated maximum path speed based on the calculated maximum path acceleration; and a speed distribution section that distributes the speed to the speed in each axial direction.

Further, the speed calculating section compares the calculated maximum route speed with the moving speed input as the route command value, and outputs the smaller speed as the calculation result.

(Operation) In the present invention, the speed calculation section calculates the maximum operable speed from the maximum allowable speed of each axis and the command value of the route. Also, since this value is compared with the command speed and the smaller one is output,
Even if a command value that exceeds the constraint conditions is input, the speed is automatically corrected to the maximum allowable speed. Further, the acceleration calculation unit calculates the maximum operable acceleration using the maximum allowable acceleration of each axis and the command value of the path.

[Embodiment] FIG. 1 shows the configuration of an embodiment of the present invention. In the figure, (10) indicates a velocity calculation section, and (11) indicates an acceleration calculation section. The other input section (1), speed signal generation section (2), acceleration/deceleration processing section (3), and speed distribution section (4) are the same as the conventional one. FIG. 2 shows an operation flowchart centering on the velocity calculation section (1o) and the acceleration calculation section (11).

The speed calculation unit (10) receives the route command value (
Input the maximum permissible speed values Fx and Fy for each of the X and Y axes set in advance (step 1), and use these to find the path speed f using the following equation (step 2).

However, L=to rPl-P-1: Path length: Shortest travel time on a straight path For example, in the case of a path as shown in Figure 3, path 1 (5)
The path speed f, (20) is determined so that the speed in the X-axis direction is Fx, and the path speed f2 (21) of path 2 (6) is Y
The axial speed is determined to be FY. That is, (A
), the path speed f is determined as the maximum path speed that satisfies the condition that all of its axial components are smaller than the maximum allowable speed value for that axis.

This route speed f is compared with the speed command value F input from the input section (1), and the smaller one is outputted to the speed signal generation section (2) as a new speed command value V (step 3).

V=MIN (F, f) − (B) On the other hand,
The acceleration calculation unit (11) calculates preset maximum allowable accelerations Ax and AY for each of the X and Y axes, and a route command value (x
.

However, if x=O, the first term in the right-hand side () is excluded; if Y=O, the second term in the right-hand side 0 is excluded. )
The path acceleration A, (22) of path 2 (6) is determined to be the acceleration in the X-axis direction or Ax, and the path acceleration A2 (2
3) is determined so that the acceleration in the Y-axis direction is AY. That is, by equation (C), path acceleration A is determined as the maximum path acceleration that satisfies the condition that all axis components are smaller than the maximum allowable acceleration of that axis.

Thereafter, as in the conventional case, the speed signal generating section (2) receives the calculation result of the speed calculation section (1o) and generates a step-like speed of height V and time width T (T=L/V). The acceleration/deceleration processing section (3) generates a signal S, and the acceleration/deceleration processing section (3) converts the rise and fall of this step-like speed signal S into the acceleration calculation section (11).
The velocity distribution unit (4) determines the X-axis component vx and Y-axis component vY of the accelerated/decelerated velocity waveform V. These series of operations are repeated for each block of route command values.

FIG. 5 shows operational waveforms of each part associated with the above operation. Fifth
Figures (a) to (d) show the pressure waveform S of the speed signal generator (2).
Then, the height of the step-like velocity waveform or the velocity calculation section (lO)
This shows the situation in which the maximum value is selected for each route based on the calculation results. Figure 5(b) shows the output waveform V of the acceleration/deceleration processing section (3).
Then, the slope (acceleration) of the speed change is calculated by the acceleration calculation section (11)
This shows the situation in which the maximum value is selected according to the route based on the calculation results. Figures 5(C) and 5(d) show the velocity distribution section (4), respectively.
) is the X-axis component v of the accelerated/decelerated speed waveform ■ output by
×, Y-axis component! Post Y.

FIG. 6 is a block diagram showing the configuration of another embodiment of the speed control device of the present invention. In the figure, (30) is the shaft speed calculation section, (31) is the shaft speed calculation section, (2a), (2
b) are the X-axis and Y-axis speed generators, respectively, (3a),
(3b) are X-axis and Y-axis acceleration processing units, respectively.

The axis speed calculation unit (30) uses the command values (x, y) for the linear route input from the input unit (1) and the maximum allowable speeds FX, FY for each of the X and Y axes given in advance to calculate the route. Calculate each axis component of the maximum operable speed using the following formula.

FX Using f, , fY obtained in section (30) and the maximum permissible accelerations A, , AY of each axis given in advance, each axis component aX+aY of the maximum operable acceleration of the route is calculated by the following equation.

fx fY However, W=MAX(-・-) A× ^Y ; Shortest acceleration time to path speed f The X-axis speed signal generation section (2a) is the speed calculation section (30)
Receiving fX obtained in , size fx, time width T = (T
=x/fx), and generates a step-like speed signal SX of
It is output to the shaft motion deceleration processing section (3a). The X-axis acceleration/deceleration processing section (3a) shapes the rise and fall of the step-like speed signal SX in accordance with ax determined by the acceleration calculation section (31), and outputs it as an X-axis speed command.

Similarly for the Y-axis, the Y-axis speed signal generator (2b)
receives fY obtained by the speed calculation unit (30), generates a step-like speed signal SY of magnitude fY and time width T (T=Y/fY), and generates a Y-axis dynamic deceleration processing unit (3b). Output to. The Y-axis acceleration/deceleration processing unit (3b) is an acceleration calculation unit (3b).
In accordance with ay obtained in 1), the step-like speed signal SY is
The rising and falling edges are shaped and output as the Y-axis speed command.

〔Effect of the invention〕

As described above, in the speed control device of the present invention, the maximum velocity and maximum acceleration of each drive axis or the straight path that satisfies the constraints of the drive system are calculated for each command unit of the path, and control is performed using these. Therefore, the travel time can be significantly reduced compared to the conventional method of giving individual speed command values or accelerating/decelerating at a constant acceleration. You can also get the effect that the speed is automatically adjusted to the maximum allowable speed.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the speed control device of the present invention, FIG. 2 is a flowchart showing its operation, and FIG. 3 is an explanation showing an example of the operation of the speed calculation section of this embodiment. 4 is an explanatory diagram showing an example of the operation of the acceleration calculation section of this embodiment, FIGS. 5(a) to (d) are explanatory diagrams of operation waveforms of the speed control device in this embodiment, and FIG. A block diagram showing the configuration of another embodiment of the speed control device of the present invention, FIG. 7 is a block diagram showing the configuration of a conventional speed control device, and FIG. 8 is an explanation showing an example of the operation of the conventional speed control device. Figure, Figure 9 (a
) to (d) are explanatory diagrams of operating waveforms of a conventional speed control device. In the figure, (1) is an input section, (2) is a speed signal generation section, (3) is an acceleration/deceleration processing section, (4) is a speed distribution section, and (10) is an acceleration/deceleration processing section.
) is a velocity calculation section, and (11) is an acceleration calculation section. No. 1 (a) (C) No. 1 (a) (C) No. 1 (spontaneous) amendment to the procedure of drawing No. 11 (spontaneous) Relationship with the Control Device 3° Amendment Case Patent Applicant Address 2-2-3 Marunouchi, Chiyoda-ku, Tokyo
Name (601) Mitsubishi Electric Corporation Representative Moriya Shiki (c) 4゜

Claims (2)

[Claims] (1) Based on the path command value consisting of the movement amount and movement speed of each drive axis that moves the moving body along a fixed path, calculate the axis speed command of each drive axis and output it to the control unit. The control device includes a speed calculation unit that calculates a maximum path speed based on the route command value and the preset maximum allowable speed of each axis, and a speed calculation unit that calculates the maximum path speed based on the route command value and the preset maximum allowable acceleration of each axis. an acceleration calculation unit that calculates the maximum path velocity, an acceleration/deceleration processing unit that accelerates and decelerates the calculated maximum path velocity based on the calculated maximum path acceleration, and an acceleration/deceleration processing unit that accelerates and decelerates the calculated maximum path speed based on the calculated maximum path acceleration; A speed control device comprising: a speed distribution section that distributes speed to (2) The speed calculation unit compares the calculated maximum route speed with the travel speed input as the route command value, and outputs the smaller speed as the calculation result. Speed control device as described.