JPH0345636B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a pulse motor control circuit that performs positioning operations of a plurality of movable axes at high speed in an apparatus having a plurality of movable axes, such as an industrial robot. .

Conventional configuration and its problems Generally, when controlling one axis or multiple axes at the same time, such as the arm of an articulated robot, one-axis pulse motor control circuits are arranged for the number of axes as shown in Figure 1. There is something. The operation of one axis will be explained using this figure. First, CPU1 receives the number of moving pulses Na from the outside.
When received, the address φ is output to the ROM2. When the φ address is called, the ROM 2 outputs frequency division ratio data Ddiv to the frequency divider 3. The frequency divider 3 divides the frequency of the reference pulse f into 1/Ddiv according to the applied data Ddiv, and outputs the pulse output Pout. fout=f·1/Ddiv. ROM2 contains data that decreases as the address increases, and if the CPU 1 instructs the ROM2 to gradually increase the address output, the output frequency _put of the frequency divider 3 can be automatically changed. From a frequency below the startup,
It is now possible to gradually increase the frequency up to the highest frequency _n . Then, the address of ROM2 reaches the final address, that is, the output frequency of frequency divider 3 _{is put}
When it reaches the maximum frequency _n , it continues to fast feed at that frequency, and when it approaches the predetermined number of pulses N, it then reverses
The address of ROM2 is decreased, the frequency is gradually lowered, and the movement pulse is sent below the self-starting frequency and then stopped. Although the above is a single axis operation, in the case of multiple axes, each axis receives a different number of movement pulses and operates similarly to that described above. In Figure 1, CPU1 is moving pulse
FIG. 2 shows a speed profile when the CPU 4 receives the movement pulse Nb and the CPU 7 receives the movement pulse Nc.

Here, the number of output pulses from the frequency divider 3 is represented _{by put} a, the number of output pulses from the frequency divider 6 is represented by _put b, and the number of output pulses from the frequency divider 9 is represented by _put c. Here _put a<
If _put b < _put c, as shown in Fig. 2, in the configuration shown in Fig. 1, the acceleration end points αa, αb, αc, deceleration start points βa,
βb, βc, and stopping points γa, γb, and γc may not match. When it is necessary to drive multiple axes at the same time, such as in a multi-joint robot arm, the axis with fewer movement pulses will stop first, and the arm will vibrate due to the acceleration at that time, causing the arm to move after all axes have stopped. Positioning at the tip takes time. Furthermore, if this vibration is large, a step-out phenomenon may occur in which the pulse motor does not follow the control pulse. Furthermore, the same circuit must be provided for each axis, making the circuit complex and expensive.

OBJECT OF THE INVENTION The present invention eliminates the drawbacks of the conventional pulse motor control device, and provides a simple configuration.
A pulse motor control device that can perform high-speed positioning by starting, ending acceleration, and starting deceleration of a pulse motor on multiple axes at the same time and reducing the vibration of the driven object without increasing the load on the CPU. This is what we provide.

Composition of the Invention The pulse motor control device of the present invention includes installing a rate multiplier given data having a certain relationship with the number of moving pulses in front of a frequency divider that divides the reference pulse f by given data. By giving the same data to multiple frequency dividers at the same time, multiple axes with different numbers of movement pulses can start accelerating at the same time.
This makes it possible to end acceleration, start deceleration, and stop.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be shown and described below. Third
The figure is a block diagram of one embodiment of the present invention. This embodiment shows an example of three-axis control. First, CPU10
receives the number of movement pulses Nx, Ny, Nz for three axes from the outside. Next, the CPU 10 performs the following calculation, setting the largest data of the number of moving pulses as N _MAX (in this example, N _X =N _MAX , Nx:Ny:Nz=5:3:1).

Rx = Nx/N _MAX = 5/5 = 1 Ry = Ny/N _MAX = 3/5 = 0.6 Rz = Nz/N _MAX = 1/5 = 0.2 The values obtained by this calculation are the respective data,
In other words, it is the output of the rate multipliers 12, 13, and 14 corresponding to the number of moving pulses Nx, Ny, and Nz1, that is, the ratio of _put x, _put y, and _put z.

Here rate multipliers 12, 13, 14
is the rate number N, then 1/N of the reference clock according to the given data Dn from 1 to N.
It is a device that multiplies Dn. In other words, the outputs of rate multipliers 12, 13, and 14 are Pout,
Pout=f·Dn/N, which is 0foutf.

Assuming that the number of rates is 100, the following data is given to the rate multiplier for each axis.

Dnx=100・Rx, Dny=100・Ry, Dnz=100・
Rz, then rate multiplier 12,1
The outputs of 3 and 14 are respectively Poutx=f・100Rx/100=f・Rx=f Pouty=f・100Ry/100=f・Ry=0.6・f Poutz=f・100Rz/100=f・Rz=0.2・f becomes. In other words, an output Pout proportional to the number of movement pulses for each axis can be obtained. This output Pout becomes a clock signal for the frequency divider of each corresponding axis.

Here, when the CPU 10 receives a movement start command from the outside, it first outputs the address φ of the ROM 11. The data D _DIV at the φ address is simultaneously given to the frequency dividers 15, 16, and 17 of each axis as frequency division ratio data. The frequency divider for each axis converts the respective clock signals Poutx, Poty, Poutz into frequency division ratio data D _DIV
Divide the frequency by and output the number of output pulses _put x, _put y, _put z
Output. Here, _put x=P _put x/D _{DIV put} y=P _put y/D _{DIV put} z=P _put z/D In _DIV ROM11, as the address increases,
Since it contains data whose data size is decreasing, the CPU 10 issues a command here.
If the ROM address is gradually increased from the φ address to the final address, the change in the pulse output of each axis will be the same as the fourth one.
It will look like the figure. At this point, the ROM address reaches the final address, that is, the pulse output frequency reaches the maximum speed _nax.
When it reaches the speed, it continues to feed at that speed for a while, and when it approaches the number of feed pulses N to decelerate, it decreases the ROM address and starts each axis at a frequency below the self-start frequency. The pulse output is stopped. The speed profile explained so far is shown in FIG.

In FIG. 5, the ratio of the areas of the trapezoid formed by the three velocity profiles, that is, the X, Y, and Z axes, is equal to the ratio of the number of output pulses, that is, _put x, _put y, and _put z. Let the areas of this trapezoid be Qx, Qy, and Qz.

The highest frequencies of the X, Y, and Z axes _{are nax} x, _nax y,
If _nax z, _nax x=Rx・_nax , _nax y=
Ry・_nax , _nax z=Rz・_nax , so Qx,
Qy and Qz are respectively Qx=(1/ _2tup +tslew+1/2tdwn ₎・_nax Therefore, Qx:Qy:Qz= _nax x: _nax y: _nax z = Dnx: Dny: Dnz = Nx: Ny: Nz 5:3:1.

Therefore, it becomes one axis of the multi-axis pulse output.
For example, if the number of output pulses for the axis whose number of travel pulses Nx is equal to Nmax is managed so that the number of output pulses becomes the number of travel pulses, the output pulse number Q of the remaining axes will automatically become the number of travel pulses N according to the X axis. be equal. Note that the rate multiplier used here can be configured using Intel's programmable interval timer LSI, i-8253. A block diagram of one example is shown in FIG. 6, and a timing chart thereof is shown in FIG. Here, the programmable timer 18 receives data from the CPU 10.
When Dn is received, OUT is set to H level. While Dn counting the reference clock f, OUT of the programmable timer 18 is at the "H" level, and then drops to the "L" level.

This OUT signal and the reference clock f are passed through an AND circuit 21 to form an output signal fout. The reference clock f also serves as an input signal to the 1/100 counter 20. This 1/100 counter 20 is f
Outputs a short trigger pulse every time it counts 100. This trigger pulse is output to GATE of the programmable timer 18 as a trigger signal when the programmable timer 18 starts counting Dn. FIG. 7 shows the case where Dn=4. At this time, the output is _put = f・Dn/100=
It becomes 0.04・f. In this example, i8253 was used, but
In addition, the same effect as the above rate multiplier can be obtained by, for example, using a frequency divider to set the frequency division ratio data to an appropriate value.

Effects of the Invention As described above, in the present invention, in order to simultaneously drive a multi-axis pulse motor, a frequency divider proportional to the number of movement pulses is installed before each frequency divider that outputs control pulses to the pulse motor. A clock is added to the frequency divider. Therefore, the data that is updated and given to the frequency divider one after another to perform acceleration/deceleration can be the same data for all axes at the same time, and the load on the CPU does not change even if the number of axes increases. Furthermore, the number of axes that can be driven simultaneously can be easily increased simply by adding a rate multiplier and a frequency divider. In addition, since the start, end of acceleration, start of deceleration, and stop of each axis are performed simultaneously for all axes, positioning can be performed at high speed and with less vibration, which is extremely effective. In addition, in the example,
Although we have explained the case of multi-axis control, even in the case of single-axis control, the maximum speed can be achieved without complicated calculations by simply varying the rate multiplier data.
Its effects are great, such as being able to change _nax .

[Brief explanation of drawings]

Fig. 1 is a block diagram of a conventional pulse motor multi-axis control circuit, Fig. 2 is a speed profile of the conventional device, Fig. 3 is a block diagram showing an embodiment of the present invention, and Figs. 4 and 5 are the same. FIG. 6 is a block diagram showing an example of a rate multiplier, and FIG. 7 is a time chart thereof. 10...CPU, 11...ROM, 12,13,
14...Rate multiplier, 15, 16, 17
...Frequency divider.

Claims (1)

[Scope of Claims] 1. Data generation means for generating data obtained by dividing the number of drive pulses of each of the plurality of pulse motors by the maximum number of the number of drive pulses of each of the plurality of pulse motors to be controlled, and the plurality of pulses to be controlled. a frequency converting means provided corresponding to each motor and converting a reference clock signal into a pulse signal having a frequency mutually proportional to each data generated by the data generating means; and an acceleration/deceleration profile from drive start to stop. frequency division ratio data generation means for sequentially generating frequency division ratio data according to the frequency division ratio data generation means; A pulse motor control device comprising: frequency dividing means for frequency dividing a pulse signal from the frequency converting means to generate pulses to be applied to each of the pulse motors.