CN202818211U - Eight-axis synchronous stepping motor based control system - Google Patents

Abstract

The utility model relates to a control system based on an 8-axis synchronous stepping motor, which includes an MCU, a power supply module, a serial communication module, a motor limit switch detection module and a PWM photoelectric isolation output module. The serial communication module is connected to receive the control and query instructions of the upper PC, and send the position information of the stepping motor to the PC; the single chip is connected to the PWM photoelectric isolation output module, and outputs PWM square waves of different frequencies and directions to the step Into the motor driver; the single-chip microcomputer is connected with the motor limit switch detection module to detect the starting point and end position information of the 8-axis stepping motor; the main power supply of the system is output by the DC/DC module to provide power for the serial communication module separately to realize serial communication The bus is isolated from the MCU's power supply. By receiving serial commands from the host computer, the utility model adopts 8-way independent PWM to realize synchronous control of 8-axis stepping motors, which can simplify system design and improve efficiency.

Description

Based on 8-axis synchronous stepping motor control system

technical field

The utility model belongs to a control system of a stepping motor, in particular, an 8-axis synchronous stepping motor control system.

Background technique

With the development of microelectronics and computer technology, the demand for stepper motors is increasing day by day, and they are used in various national economic fields. The speed of the stepper motor is proportional to the input pulse frequency, and the speed of the stepper motor can be accurately controlled by controlling the input pulse frequency, and the speed can be precisely adjusted in a wide range. Therefore, stepper motors are widely used in winding machines, slicers, engraving machines, cable machines, packaging machinery, food processing industry, copiers, engraving machines, cable controllers, medical equipment, stage lighting, optoelectronic technology, automation engineering, robotic applications, etc.

At the beginning of the digital control system, the stepping motor has gone through a big stage of development. In Japan, in the early 1960s, reluctance stepping motors for numerical control devices and computer peripherals were developed. Since the mid-1960s, a hybrid stepping motor has been developed. In our country, the development of stepper motors began in 1958. At that time, only a few institutions of higher learning such as Tsinghua University and Huazhong University of Science and Technology were engaged in this work. At the end of the 1960s and the beginning of the 1970s, due to the development of the electronics industry and digital technology, especially the development of digitally controlled wire cutting machine tools, the research work on stepping motors was vigorously carried out. After more than 40 years of development, with the improvement of the theory of stepping motors, especially the reluctance stepping motors, the serialization of product varieties, specifications, and categories, and the emergence of superior brushless DC motor systems It is the servo system that makes the development momentum of the stepper motor moderate. Generally speaking, its development is currently flattening.

Invention content:

The purpose of the utility model is to provide a control system based on 8-axis synchronous stepping motor with simple structure, stable and reliable performance and high operation precision, so as to overcome the shortcomings of the prior art.

In order to achieve the above object, the technical solution adopted in the utility model is:

A control system based on 8-axis synchronous stepping motor, including MCU, power supply module, serial communication module, motor limit switch detection module, PWM photoelectric isolation output module and indicator light display module. Its characteristics are: the single chip microcomputer in the MCU It is connected with the serial communication module to receive the control and query commands of the upper PC, and send the position information of the stepper motor to the PC; the single-chip microcomputer is connected with the motor limit switch detection module to receive the starting point and End position information; the microcontroller is connected to the PWM photoelectric isolation output module, and outputs PWM square waves of different frequencies and directions to the stepper motor driver.

The MCU adopts PIC18F67K90 single-chip microcomputer, receives the 8-axis stepping motor motion control and query commands sent by the external PC through the serial communication module, and loops the 8 independent PWM modules inside the single-chip microcomputer to realize the control of the 8-axis stepping motor. Synchronous operation; the MCU microcontroller sends the position information of the 8-axis stepper motor to the external PC through the serial communication module.

The above-mentioned 8-axis stepping motor motion control command corresponds to the synchronous operation status of the 8-axis stepping motor, including any 1 axis of the 8-axis stepping motor running independently, any 2 axes running at the same time, any 3 axes running at the same time, and any 4 axes running at the same time. Simultaneous operation of axes, simultaneous operation of any 5 axes, simultaneous operation of any 6 axes, simultaneous operation of any 7 axes, simultaneous operation of 8 axes, and simultaneous stop of any 1 axis of the 8-axis stepping motor, simultaneous stop of any 2 axes, simultaneous stop of any 3 axes , any 4 axes stop at the same time, any 5 axes stop at the same time, any 6 axes stop at the same time, any 7 axes stop at the same time, and 8 axes stop at the same time. Its characteristics are: the motor operation control command includes the target operation steps setting (0~99999999) , Target running direction setting (0, 1), target running speed setting (00~99) and start running setting. After receiving the running control command, the microcontroller outputs PWM pulses through the PWM photoelectric isolation output module, in which the number of PWM pulses is equal to the number of target running steps, the PWM frequency is linearly proportional to the target running speed, and the PWM starting acceleration frequency is proportional to the target starting acceleration. Linear proportional relationship. Among them, the target operation step setting feature is that the range of target operation steps that can be set for one operation control command is 0 to 99999999, which means that any 1 axis motor of an 8-axis stepper motor can run a target step range of 0 to 99999999 ;

The target operating speed setting feature is that the target operating speed range that can be set by the operating control command is 00~99, of which 99 represents the highest speed that the external stepping motor driver can drive the corresponding stepping motor, and 00~98 is a linear proportional relationship .

For the above-mentioned 8-axis stepping motor query command, after the MCU receives the external PC query command, it sends the 8-axis position information to the PC through the serial communication module in real time, and the query command corresponds to the real-time position information of the 8-axis stepping motor. Including any 1-axis position information of 8-axis stepping motor, any 2-axis position information, any 3-axis position information, any 4-axis position information, any 5-axis position information, any 6-axis position information, any 7-axis position information, 8-axis location information.

The power-down protection circuit in the MCU uses a MAX803 chip. When a sudden power failure occurs, the chip sends an external interrupt signal to the single-chip microcomputer, and the single-chip microcomputer immediately saves the current operating position information of the motor. When the power is turned on again, the single-chip microcomputer reads the saved position information.

The main power supply in the power module is output through the DC/DC module to provide power for the serial communication module separately, so as to realize the power isolation between the serial communication bus and the MCU.

Owing to adopting above-mentioned technical scheme, the utility model has the following points and innovations compared with the prior art:

1) The main power supply in the power supply module of the system provides separate power supply for the serial communication module through the output of the DC/DC module, so as to realize the power isolation between the serial communication bus and the MCU;

2) The power-down protection circuit is used in the MCU of the system. When a sudden power failure occurs, the chip sends an external interrupt signal to the single-chip microcomputer, and the single-chip microcomputer immediately saves the current running position information of the motor. When the power is turned on again, the single-chip microcomputer reads the saved position information;

3) By using the PIC single-chip microcomputer to realize one-to-one correspondence to the state of the 8-axis synchronous stepping motor, including any 1 axis of the 8-axis stepping motor running and stopping independently, any 2 axes running and stopping at the same time, and any 3 axes running and stopping at the same time, Any 4 axes run and stop at the same time, any 5 axes run and stop at the same time, any 6 axes run and stop at the same time, any 7 axes run and stop at the same time, 8 axes run and stop at the same time, and any 1 axis position information of the 8-axis stepping motor, Any 2-axis position information, any 3-axis position information, any 4-axis position information, any 5-axis position information, any 6-axis position information, any 7-axis position information, and 8-axis position information.

Description of drawings

Fig. 1 is the overall structural representation of the utility model;

Fig. 2 is a schematic diagram of the principle of the power-down protection circuit in the MCU of the present invention.

Detailed ways

Below in conjunction with accompanying drawing, the utility model is further described and elaborated.

As shown in Figure 1, it is a serial communication-based 8-axis 8-axis synchronous stepping motor control system of the present invention. The system is mainly composed of MCU, power supply module, serial communication module, and motor limit switch detection module. , PWM photoelectric isolation output module, indicator light display module. in:

The single-chip microcomputer (01) in the MCU adopts the PIC18F67K90 chip of Microchip Company, which is characterized in that the 8 independent PWM modules inside the single-chip microcomputer are circularly controlled, and the power-down protection circuit 06 adopts the MAX803 chip of Maxim Company. The single-chip microcomputer sends an external interrupt signal, and the single-chip microcomputer immediately saves the current running position information of the motor. When the power is turned on again, the single-chip microcomputer reads the saved position information. Figure 2 shows a schematic diagram of the power-down protection circuit principle;

The DC/DC module (05) in the power module adopts the B0505S-2W chip of MORNSUN company, which provides power for the serial communication module separately, so as to realize the power isolation between the serial communication bus and the MCU;

The serial communication module is used to receive the control and query commands of the upper PC, and send the position information of the stepper motor to the PC. Run and stop at the same time, any 3 axes run and stop at the same time, any 4 axes run and stop at the same time, any 5 axes run and stop at the same time, any 6 axes run and stop at the same time, any 7 axes run and stop at the same time, 8 axes run and stop at the same time Stop; the stepper motor query command includes any 1-axis position information of an 8-axis stepping motor, any 2-axis position information, any 3-axis position information, any 4-axis position information, any 5-axis position information, any 6-axis position information, any 7-axis position information, 8-axis position information;

The high-speed photoelectric isolating switch (02) in the motor limit switch detection module uses TOSHIBA's TLP521 chip to transmit the received starting and ending position information of the 8-axis stepping motor to the microcontroller;

In the PWM photoelectric isolation output module, the high-speed photoelectric isolation switch (07) adopts the TLP521 chip of TOSHIBA Company, and the single-channel high-speed optocoupler (08) adopts the 6N137 chip of Agilent Technologies Company, which respectively transmit PWM square waves of different directions and frequencies output by the single-chip microcomputer to Stepper motor driver.

During the operation of the utility model, when a sudden power failure occurs, the chip immediately sends an external interrupt signal to the single-chip microcomputer, and enters the interrupt program at this time, so that the single-chip microcomputer immediately saves the current running position information of the motor. When the power is turned on again, the single-chip microcomputer reads to retrieve the saved location information.

Finally, the above-mentioned implementation of the utility model is only used to illustrate the technical solution of the utility model, and all modifications and replacements carried out without departing from the spirit and principle of the utility model shall be covered by the claims of the utility model in the range.

The content not described in detail in this specification belongs to the prior art known to those skilled in the art.

Claims (1)

1. A control system based on 8-axis synchronous stepping motors, comprising MCU, power supply module, serial communication module, motor limit switch detection module, PWM photoelectric isolation output module and indicator light display module, is characterized in that: The single-chip microcomputer in the MCU is connected with the serial communication module, and the single-chip microcomputer in the said MCU is connected with the external PC through the serial communication module to send the position information of the 8-axis stepping motor, and the single-chip microcomputer is connected with the motor limit switch detection module to detect the 8-axis The starting point and end position information of the stepping motor; the single-chip microcomputer is connected with the PWM photoelectric isolation output module, and outputs PWM square waves of different frequencies and directions to the stepping motor driver.

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