KR950002405B1 - Position controlling method and apparatus of servomotor - Google Patents

Abstract

The device provides the hardware which enhances the utilization efficiency of the microprocessor as well as controls the servo motor location. The device includes: (a) a microprocessor which generates the location and speed data of the servo motor; (b) a reference pulse generator which generates the reference pulse signal according to the location and speed data of the servo motor; (c) a programmable counter which counts the reference pulse signal and location data; (d) an interrupt generator which generates interrupt signal when the counting is completed; (e) a transfer pulse generator which ceases the reference pulse signal generation when the interrupt signal is generated.

Description

Position Control Method and Device of Servo Motor

1 is a block diagram showing an embodiment of a position control apparatus for a servomotor according to the present invention.

2 is an operating waveform diagram of a portion of the apparatus of FIG.

3 is a flow chart illustrating operation of the microprocessor of FIG.

* Explanation of symbols for main parts of the drawings

11 microprocessor 12 reference pulse generator

13: Programmable Counter 14: NAND Gate

15: inverter 16: OR gate

17: monostable oscillator CNT1, CNT2, CNT3: counter

The present invention relates to a system for controlling a transfer position of an object by a servo motor, and in particular, a programmable counter of a predetermined number of bits can be used to control the transfer position by a larger number of bits as well as to control the transfer position. The present invention relates to a servo motor position control method and apparatus for minimizing processor intervention to increase the utilization efficiency of a microprocessor.

In general, in a digital servo mechanism, the servo motor controls the position of an object by counting the number of pulses of the feedback pulse signal supplied from the encoder to a predetermined range. Currently, in the reference pulse command method used for servo motor control, the number of pulses of the reference pulse indicates the amount of feed of the motor, and the frequency of the reference pulse indicates the feed rate of the servomotor. Therefore, the feed position of the servomotor can be controlled by adjusting the number of pulses of the reference pulse.

In the servo motor position control system, a 16-bit programmable counter is mainly used to count the number of pulses of a reference pulse. However, when using the 16-bit programmable counter, the maximum number of pulses that can be counted at one time is "2 ¹⁵ " (65,536), which makes it impossible to position control the feed distance corresponding to the number of pulses. In addition, there is a problem in that the maximum value of the position control of the servomotor is limited to a feed amount corresponding to the number of pulses of “2 ^16. ” In addition, the microprocessor for controlling the servomotor counts the number of pulses that are periodically counted every predetermined time. Since the value needs to be checked, the microprocessor cannot perform other tasks while counting, thereby reducing the efficiency of the microprocessor.

Accordingly, an object of the present invention is to control the transfer position of the servomotor corresponding to a counting value larger than the maximum count value of the programmable counter using a programmable counter of a predetermined number of bits, as well as to control the number of pulses corresponding to the feed amount. The present invention provides a method for controlling the position of a servomotor to further improve the utilization efficiency of the microprocessor by not using the microprocessor during counting.

Another object of the present invention is to provide a position control apparatus for a servo motor implemented in hardware to execute the position control method of the servo motor as described above.

The object of the present invention is to provide an n-bit programmable counter and a reference pulse generator to supply a feed pulse signal whose pulse number corresponds to a feed amount to the servo motor, thereby performing position control of the servo motor. Inputting a desired location data, determining whether the location data is greater than "2 ⁿ ", and if the location data is not greater than "2 ⁿ ", the n-bit programmable counter counts location data. A first output step of outputting a reference pulse signal of the reference pulse generator as a transfer pulse, and a second output of outputting a reference pulse signal REF as a transfer pulse when the position data is larger than " ²ⁿ " It is achieved by the position control method of the servo motor comprising a step.

According to another aspect of the present invention, a position control apparatus for performing position control of a servo motor by supplying a feed pulse signal corresponding to a feed amount to a servo motor, the position data and speed for controlling the position and speed of the servo motor A microprocessor for generating data, a reference pulse generator for receiving speed data from the microprocessor and generating a corresponding reference pulse signal, and a reference pulse signal from the reference pulse generator for receiving a reference pulse signal from the microprocessor. A programmable counter that receives the position data, counts the position data using the reference pulse signal as a clock, and receives a counting output signal of the programmable counter, generates a predetermined interrupt signal when the counting is completed. Interrupt to Microprocessor A transfer pulse for receiving a pulse generating means and a reference pulse signal output from the reference pulse generating unit and outputting the reference pulse signal as the transfer pulse signal, and stopping the output of the reference pulse signal when an interrupt signal is applied from the interrupt generating means. It is achieved by the position control device of the servomotor including an output.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. 1 is a block diagram showing an embodiment of a position control apparatus for a servomotor according to the present invention. A 16-bit programmable counter enables counting in a 32-bit range, and when a desired counting value is completed, that is, a transfer position The predetermined interrupt signal is generated when the control is completed.

The apparatus of FIG. 1 includes a microprocessor 11 and a reference pulse generator 12 for generating a reference pulse signal REF having a frequency varying in accordance with a predetermined speed data D _v supplied from the microprocessor 11. And a programmable counter 13 for receiving a reference pulse signal REF output from the reference pulse generator 12 and a position data D _p output from the microprocessor 11 and counting a predetermined counting value. In the NAND gate 14 receiving the output signal of the counter 13 and generating a predetermined interrupt logic signal INTL, the reference pulse signal REF and the NAND gate 14 output from the reference pulse generator 12 The OR gate 16 receives the output interrupt logic signal INTL and outputs the transfer pulse signal FP, and the interrupt logic signal INTL output from the NAND gate 14 receives a predetermined interrupt pulse signal ( Microinput by generating It comprises a monostable oscillator (17) to be applied to the processor 11.

The microprocessor 11 supplies the 8-bit speed data D _v for determining the feed speed of the servo motor to the reference pulse generator 12, and the 8-bit position data D _p for determining the feed position of the servo motor. It is supplied to the programmable counter 13. The reference pulse generator 12 generates a reference pulse signal REF having a frequency corresponding to 8-bit velocity data V _v to generate the first counter CNT1 and the third counter CNT3 of the programmable counter 13. The clock terminals CLK1 and CLK3 are applied respectively. The programmable counter 13 includes three 16 counters CNT1, CNT2 and CNT3. The power supply voltage Vcc is applied to the gate terminals GATE1 and GATE2 of the first counter CNT1 and the second counter CNT2. The first counter CNT1 and the second counter CNT2 are always counting enabled, and the third counter CNT3 is the gate terminal GATE3 and the output OUT2 of the second counter CNT2 is applied. According to the output of the second counter CNT2, the third counter CNT3 is enabled or disabled. In addition, the second counter CNT2 receives the output OUT1 of the first counter CNT1 through the clock terminal CLK2 to perform counting. The programmable counter 13 has a buffer BUF. The position data D _p output from the microprocessor 11 is stored in this buffer BUF, and a counting value is set accordingly.

Now, when the number of transfer pulses corresponding to the feed amount is "2 ¹⁶ " or less, that is, when the position data D _p supplied from the microprocessor 11 to the buffer BUF of the programmable counter 13 is "2 ¹⁶ " or less, The first counter CNT1 is not used and the output of the second counter CNT2 before the reference pulse signal REF applied from the reference pulse generator 12 is input to the clock terminal CLK3 of the third counter CNT3. Set OUT2 to a high level so that the third counter CNT3 is enabled. Accordingly, the third counter CNT3 performs down counting based on the counting value corresponding to the position data D _p in accordance with the reference pulse signal REF applied to the clock terminal CLK3. The third counter CNT3 maintains the high level output signal OUT3 when down counting is completed.

If the number of transfer pulses is larger than "2 ¹⁶ ", that is, the position data D _p exceeds "2 ¹⁶ " and the maximum value is "2 ³² ", the first counter in the programmable counter 13 (CNT1) is set to " 0 ", and the second counter CNT2 and the third counter CNT3 count 32 bit data corresponding to the position data D _p . At this time, the second counter CNT2 counts the upper 16 bits N of the position data, and the third counter CNT3 counts the lower 16 bits M. The operation timing diagram of the programmable counter 13 for this case is shown in FIG. First, the first counter CNT1 of the programmable counter 13 is supplied to the click terminal CLK1 of the reference Perks signal REF and counts "2 ¹⁶ " clock pulses. At this time, the first counter (CNT1) generates an output signal (OUT1) has a low level for one clock period each time the reference pulse count ^"216" one, as shown in FIG. 2. The output signal OUT1 of the first counter CNT1 is applied to the clock terminal CLK2 of the second counter CNT2. The value counted from the second counter CNT2 is the upper 16 bit data of the 32-bit position data ( N). If the upper 16-bit data is "N ₁₀ ", the second counter CNT2 starts counting down from " N ₁₀ " to generate a high level output signal OUT2 when the counting value becomes " 0 ". That is, the output signal OUT2 of the second counter CNT2 is maintained at the low level while the down counting is performed, and is converted to the high level when the counting is completed. The output signal OUT2 of the second counter CNT2 is input to the gate terminal GATE3 of the third counter CNT3. The third counter CNT3 is disabled because the low level signal is applied to the gate terminal GATE3 while the second counter CNT2 is counted, and when the counting of the second counter CNT2 is completed, the gate terminal CNT3 is disabled. As high level signal is applied to GATE3), it is enabled and starts counting. The third counter CNT3 counts pulses of the reference pulse signal REF input to the clock terminal CLK2. The third counter CNT3 down counts the lower 16-bit data M of the 32-bit position data. That is, if the lower 16-bit data is "M ₁₀ ", the third counter CNT3 starts down counting from "M ₁₀ " and the counting value becomes "0", so that when the counting is completed, the high level output signal ( Generates OUT3).

As such, the output signal OUT2 of the second counter CNT2 and the output signal OUT3 of the third counter CNT3 generated by the programmable counter 13 are respectively input to two input terminals of the NAND gate 14. do. Then, as shown in FIG. 2, the NAND gate 14 generates an interrupt logic signal INTL at which the level is converted when the number of pulses corresponding to the 32-bit position data is counted. This interrupt logic signal INTL is supplied to the monostable oscillator 17 and to the OR gate 16 via the inverter 15. The OR gate 16 receives the inverted interrupt logic signal INTL and the reference pulse roll signal REF output from the reference pulse generator 12 through the inverter 15, and outputs a transfer pulse signal FP. Transfer to the deviation counter (not shown) of the servo system. As shown in FIG. 2, the transfer pulse signal FP output from the OR gate 16 is high while the interrupt logic signal INTL is high, that is, while the 32-bit position data is counted by the programmable counter 13. The reference pulse signal REF is equal to the number of pulses corresponding to the 32-bit position data, and when the interrupt logic signal INTL becomes low level, that is, when the number of pulses equal to the 32-bit position data is output, the high level is obtained. On the other hand, the monostable oscillator 17 supplied with the interrupt logic signal INTL output from the NAND gate 14 converts the interrupt logic signal INTL into an interrupt pulse signal INTP having a predetermined size and shape and outputs the interrupt pulse signal INTP. do. When the interrupt pulse signal INTP output from the monostable oscillator 17 is input to the microprocessor 11, the microprocessor 11 stops outputting the speed data D _p and the position data D _p .

3 is a flowchart schematically showing the operation of the microprocessor 11 of FIG. First, the microprocessor 11 reads the desired position data D _p which is input by the user and stored as the numerical control code (step 310). Then, it is determined whether the position data D _p is greater than "2 ¹⁶ " (step 320). When the determination result position data D _p is larger than "2 ¹⁶ ", the first counter CNT1 of the programmable counter 13 is set to "0", and the second counter CNT2 positions the initial counting value. Data (D ^* ) The 16-bit data is set, and the third counter CNT3 sets the initial counting value to the lower 16-bit data of the position data D _p (step 330). When the determination result position data D _p is not larger than "2 ¹⁶ ", the first counter CNT1 is disabled, the output OUT2 of the second counter CNT2 is set to a high level state, and the third The initial counting value of the counter CNT3 is set to the position data D _p (step 340). Then, by performing the counting operation in the programmable counter 13 as described above, the reference pulse signal REF corresponding to the number of pulses corresponding to the position data D _p is output as the transfer pulse signal FP.

As described above, the position control system of the servomotor according to the present invention can control the feed amount of the servomotor within the range of "2 ³² " using 32-bit position control data while using a 16-bit programmable counter. In addition, if the feed amount of the motor is initially input to the programmable counter by software, the position control can be simply performed without the involvement of the microprocessor until the positioning is completed, thereby increasing the utilization efficiency of the microprocessor.

Claims (12)

In the position control method for performing the position control of the servo motor by supplying a transfer pulse signal of n-bit programmable counter and a reference pulse generator to the servo motor, the number of pulses being supplied to the servo motor, the desired position data is inputted. Doing; Determining whether the location data is greater than "2 ⁿ "; A first output step of outputting a reference pulse signal of the reference pulse generator as a transfer pulse while the n-bit programmable counter is counting the position data when the position data is not larger than "2 ⁿ "; And a second output step of outputting a reference pulse signal REF as a transfer pulse when the position data is larger than "2 ⁿ ". REF = N × 2 ⁿ + M Here, REF is the number of pulses of the reference pulse signal, N is upper bit data corresponding to higher than n bits of the position data, and M is lower bit data up to n bits of the position data. The first counting step of claim 1, wherein the second output step performs modulo − 2 ⁿ counting using the reference pulse signal as a clock, and generates a predetermined pulse signal each time 2 ⁿ is counted. ; A second counting step of counting the higher bit data N using the pulse signal of the first counting step as a clock; And a third counting step of counting the lower bit data (M) from a time point when the counting operation of the second counting step is completed. The method of claim 2, wherein the second output step further comprises the step of stopping the output of the reference pulse signal when the counting operation of the second counting step is completed and the counting operation of the third counting step is completed. Position control method of the servo motor, characterized in that. The method of claim 1, wherein the first outputting step comprises: generating a predetermined interrupt pulse signal when a counting operation of the n-bit programmable counter is completed; And when the interrupt pulse signal is generated, stopping the output of the reference pulse signal. In the position control device for supplying a feed pulse signal corresponding to the number of pulses to the servo motor to perform the position control of the servo motor, the microcomputer generates position data and speed data for controlling the position and speed of the servo motor. A processor; A reference pulse generator for receiving speed data from the microprocessor and generating a reference pulse signal corresponding thereto; A programmable counter that receives a reference pulse signal from the reference pulse generator and receives position data from the microprocessor, and counts the position data using the reference pulse signal as a clock; Interrupt generating means for receiving a counting output signal of the programmable counter and generating a predetermined interrupt signal at the time point at which counting is completed; A servo including a transfer pulse output unit receiving a reference pulse signal output from the reference pulse generator and outputting the reference pulse signal as the transfer pulse signal, and stopping the output of the reference pulse signal when an interrupt signal is applied from the interrupt generating means; Motor position control device. The apparatus of claim 5, wherein the programmable counter comprises: a first counter that repeatedly counts a predetermined counting period by using the reference pulse signal as a clock, and outputs a predetermined pulse in each counting period; A second counter that counts a predetermined counting value using the output signal of the first counter as a clock, and outputs an enable signal having a predetermined level when the counting is completed; And counting a predetermined programmed counting value using the reference pulse signal as a clock when an enable signal is applied when the output signal of the second counter is applied, and outputs a signal having a predetermined level when the counting is completed. Position control apparatus for a servo motor comprising a third counter. 7. The method of claim 6, wherein when the position data is not greater than the maximum counting data of the programmable counter, the first counter is in a disabled state, and the second counter continuously outputs the enable signal. And a third counter is programmed to count the position data. 7. The method of claim 6, wherein when the position data is larger than the maximum counting data of the programmable counter, the first counter is initialized to "0", and the second counter is higher than the counting data of the programmable counter among the position data. And the third counter is programmed to set the lower bit data except the upper bit data among the position data as the counting value. The method of claim 5 or 6, wherein the interrupt generating means is supplied with the output signal of the second counter to the first input terminal and the output signal of the third counter to the second input terminal, the two inputs And a logic circuit for outputting the interrupt signal by performing a predetermined logic operation on a signal. 9. The position control method of a servomotor according to any one of claims 6, 7, or 8, wherein the second counter and the third counter are downtown. The microprocessor of claim 5, wherein the interrupt logic signal is coupled between the interrupt generating means and the microprocessor, receives an interrupt logic signal from the interrupt generating means, and outputs an interrupt pulse signal having a predetermined magnitude and period to the microprocessor. Position control apparatus for a servo motor further comprising a monostable oscillator. 7. The position control method of a servomotor according to claim 5 or 6, wherein the programmable counter is a 16-bit counter that processes 16-bit data as counting data.