JPH07160337A - Positioning control method - Google Patents

Abstract

PURPOSE:To provide the positioning control method, which moves the movable body of a machine tool, etc., smoothly to a target position on the fixed part side with high precision in a driving device system which has the movable body and fixed part sides of the machine tool, etc. CONSTITUTION:When the movable body 1 equipped with a driving source 2 is moved to the target position X1 on the side of the fixed part 3 by the driving of the driving source 2, the driving source 2 is controlled by a computer- incorporated control part 6 and a position sensor 4 detects the movement position of the movable body 1. When the movable body 1 is moved to the target position X1, an interruption signal is inputted to the control part 6 at constant intervals and a position signal generated by the position sensor 4 is inputted; and the speed of the movable body 1 is calculated and the optimum output of the driving source 2 is calculated from the speed to move the movable body 1 to the target position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive system having a movable body such as a machine tool and a fixed portion side so that the movable body can be smoothly moved to a target position on the fixed portion side with high accuracy. The present invention relates to the positioning control method.

[0002]

2. Description of the Related Art Generally, in such a drive system, in order to perform positioning control of a movable body, the movable body is driven by a drive source such as a DC motor, while a position sensor for position detection is provided on the movable body side. In addition to the provision, a linear scale corresponding to the position sensor is provided on the fixed portion side.

That is, the current position of the movable body is read from a position sensor and a linear scale, and this position signal is input to a control unit built in the computer. The calculation processing is performed from the position signal of the position and the position information of the movable body to the target position, and the output power corresponding to the distance to the target position is applied to the drive source of the movable body.

[0004]

However, as described above, when the output power corresponding to the distance to the target position is simply added, the frictional resistance of the drive source or the movable body portion during actual movement or Since the weight and the like are not taken into consideration, the movement time and the convergence time may deviate.
Further, even if the movable body reaches the target position and the applied power is zero, the movable body may not stop accurately at the target position. Further, in such a case, there is a problem that vibration is likely to occur. Further, in the above control method, the built-in computer of the control unit is occupied by the positioning control operation,
There is also a problem that the built-in computer cannot be used due to other processing.

The present invention has been made in view of the above conventional problems, and causes the built-in computer of the control unit to perform an interrupt routine process for positioning control in addition to the main routine process. This invention provides a positioning control method in which the moving speed of a movable body is obtained at regular intervals, the optimum output power for a drive source is calculated based on this moving speed, and optimal control is performed.

[0006]

A feature of the present invention is that when a movable body having a drive source is moved to a target position on the fixed portion side by driving the drive source, the drive source is built in a computer. Controlled by the control unit,
A position sensor is used to detect the moving position of the movable body, and when the movable body moves to a target position, an interrupt signal is input to the control unit at regular intervals to capture the position signal from the position sensor. In the positioning control method, the speed of the movable body is calculated, the optimum output of the drive source is calculated based on the speed, and the movable body is moved to the target position.

[0007]

As described above, according to the present invention, since the interrupt signal is input to the control unit to perform the interrupt routine process, the moving speed of the movable body is fed back to the drive source of the movable body. Optimal output power is obtained. As a result, it is possible to perform positioning control with extremely little time lag and vibration. Further, according to this control method, since the built-in computer of the control unit is not occupied only by the positioning control, the computer can be used with high efficiency.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of a drive system for carrying out a positioning control method according to the present invention. In the figure, 1 is a movable body provided with a drive source 2 such as a DC motor, 3 is a long fixed part composed of a pedestal on which the movable body 1 is slidably installed, and 4 is installed on the movable body 1. A position sensor such as a magnetic head, 5 is a linear scale such as a magnetic scale provided on the fixed unit 3 side, 6 is a control unit with a built-in computer, and 7 is an interval for sending an interrupt signal to the built-in computer of the control unit 6 at regular intervals. A timer, 8 is an operation unit including a keyboard of the control unit 6, 9 is a display unit such as a CRT for displaying control contents, 10 is an output device such as a printer for outputting a control result, etc.
Reference numeral 1 is a recording medium which also includes a prop for recording control results and the like. And this drive system is
It is driven by the main routine processing and the interrupt routine processing for positioning control shown in FIG. 2 and FIG.

Next, in this drive system, the movable body 1
Will be described, for example, when moving from a certain point X ₀ on the fixed portion 3 side shown in FIG. 1 to the target position X ₁ . In this case, first, as shown in the main routine process of FIG. 2, the target position X ₁ is determined in step S ₁ , and thereby the movement start flag is determined to be “1” in step S ₂ . By this, the distance to the target position X ₁ is calculated, and the movement of the movable body 1 in the target direction is started.

At this time, the speed of the movable body 1 should ideally be decelerated as shown by the linear speed characteristic line I as shown in the graph of FIG. Considering points such as the capacity and cost of No. 2, initially, as shown in the output power characteristic line II of FIG. 4, the drive source 2 is started by giving the maximum output power of the capacity fully opened.

While the application of the output power continues as it is, when the interrupt signal is received from the interval timer 7, the interrupt routine process shown in FIG. 3 is activated, and the number of interrupts is increased as shown in step S _11. It is counted, and in step S ₁₂ , it is determined whether or not the number has reached a predetermined number. In the case of "NO", via a return instruction returns to the main routine in FIG. 2, the normal processing shown in Step S ₃ of the Figure 2 is performed.
That is, while the number of interrupts does not reach the predetermined number, the built-in computer of the control unit 6 is extremely effectively used for other processing.

On the other hand, in step S ₁₂ , if the number of interrupts has reached the predetermined number, that is, "YES", the position sensor 4 reads the position information of the linear scale 5 in step S ₁₃ , and the scale is read. memory storing a value at step S ₁₄ makes (recording). Next, as shown in step S ₁₅ , the moving speed of the movable body 1 is calculated by comparing the moving start point and the previous scale value with the current scale value, and this moving speed value is stored in the memory in step S ₁₆ . To store (record).

Thereafter, based on this speed value, as shown in step S ₁₇ , the optimum output power (output value) of the drive source 2 is calculated, and the calculated control output power is calculated in step S ₁₈ . Output to the drive source 2 side, and then step S
_As indicated by ₁₉ , it is determined whether or not the movable body 1 has reached the target position X ₁ , that is, whether or not the movement has ended. If the movement is “YES”, step S
_Proceeding to ₂₀ , the movement start flag is set to "0". In step S _21, a check of the movement start flag. In step S _19, if "NO", immediately checks the movement start flag in step S _21.

[0014] After the check of the moving start flag, again performs the movement of the termination decision is made in step S _22, after confirming, "N
In the case of "O", the process immediately returns to the main routine process of FIG. 2 through the return instruction to prepare for the next interrupt. On the other hand, if the determination of the movement end is “YES”, then
Because the interrupt is not required, the process proceeds to step S _23, interruption is stopped, also through a return instruction returns to the main routine of FIG. At this time, the built-in computer of the control unit 6 is released from the positioning control.

In such positioning control, the actually measured moving speed of the movable body 1 is the speed characteristic line II in FIG.
Indicated by I, halfway portion of the target position X ₁ is moved at a constant speed, from a certain point in close proximity to the target position X _1, grain fine speed (drawing a polygonal line portion) and, correspondingly, the output It can be seen that the power is also gradually attenuated in a curve and converges to zero just at the target position X ₁ .

If desired, such positioning control operation data can be checked or saved by the output device 10 such as a printer or the recording medium 11 such as a floppy. Of course, the operation data can be easily input and changed by using the operation unit 8 such as a keyboard.
Since it is displayed on the display unit 9 such as T, it can be quickly performed while confirming the display.

In the drive system of the above embodiment, the movable body such as a machine tool and the fixed portion are set. However, the present invention is not limited to this, and the movable body and the fixed portion are relative to each other. It may be two objects that move dynamically. Further, the position sensor and the linear scale are not limited to the magnetic head and the magnetic scale.

[0018]

As is apparent from the above description, the positioning control method according to the present invention provides the following excellent effects.

(1) First, in the movement control of the movable body,
Since the control unit activates the interrupt routine process for positioning control to obtain the moving speed of the movable body and feed back this moving speed to sequentially calculate the optimum output power of the movable body, It is possible to perform highly accurate and smooth positioning control without being substantially affected by frictional resistance and weight.

(2) As a result, as in the case of the conventional control method of this type, when the moving time or the convergence time is deviated or the movable body reaches the target position, the applied power is set to zero. Also, inconveniences such as not accurately stopping at the target position are eliminated. In addition, the smooth stop effectively eliminates vibrations and the like.

(3) Further, since the positioning control is performed by the interrupt routine processing for the control unit, the built-in computer of the control unit is not occupied by the positioning control, and the number of interrupts is predetermined. Until the number of times is reached (free time), other normal processing can be performed by the built-in computer, and the built-in computer can be used with high efficiency.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view showing an embodiment of a drive system for carrying out a positioning control method according to the present invention.

FIG. 2 is a flowchart showing a main routine process of the drive system of FIG.

3 is a flowchart showing an interrupt routine process for positioning control of the drive system of FIG.

4 is a graph showing the relationship between the output power or moving speed of the movable body and the moving distance in the drive system of FIG.

[Explanation of symbols]

1 Movable body 2 Drive source 3 Fixed part 4 Position sensor 5 Linear scale 6 Control part 7 Interval timer X ₁ Target position

Claims (1)

[Claims] 1. In moving a movable body having a drive source to a target position on the fixed portion side by driving the drive source,
The drive source is controlled by a control unit built in a computer, and the moving position of the movable body is detected by a position sensor. When the movable body moves to a target position, the control unit interrupts at regular intervals. A signal is input, the position signal from the position sensor is taken in, the speed of the movable body is calculated, the optimum output of the drive source is calculated based on the speed, and the movable body is moved to the target position. A positioning control method characterized in that