[Tianjin University] Modular numerical control technology experimental device

[Modular CNC Technology Experimental Device]

Function, role introduction

Introduction

The QSSJ-1 open CNC technology experimental system is aimed at the integration of theoretical knowledge and engineering practice in the process of numerical control technology course for students of electrical automation and mechanical integration in colleges and universities, in order to realize knowledge verification, innovative design and theory. Research and experimental equipment designed for the purpose of research projects. Students can not only complete the design of automatic control programs through the understanding of theoretical knowledge, but also get engineering practice exercises such as electrical operation, engineering assembly, and electrician training.

The system is designed in a modular structure that can be flexibly combined, easily upgraded and maintained. Different experimental units can be installed on the all-steel system frame. Each unit is equipped with a connection port with electrical protection that can realize system cascade and replacement, which makes the experimental project replacement, upgrade and maintenance of the system very convenient. Each functional unit is designed with a powerful operator panel that provides a wealth of experimental teaching content. The structure of the open front panel can also facilitate the teaching guidance of teachers while satisfying the operation of 3 to 5 students. On the back of the system, two 800mm*600mm mesh plates are installed, so students can carry out various assembly and training of various machine tools.

The open CNC technology experimental system can be based on different teaching requirements by "control unit", "drive principle experimental unit", "machine control experiment unit", "servo drive unit", "motor unit", "XY motion platform", "Strong electric control unit", "control software".

Numerical control unit

The unit is the control core of the open experimental system. It can be equipped with PMAC Clipper motion control card to connect with computer via USB or Ethernet network to complete PC-based open CNC system control. It can also be equipped with embedded system control board (SCM) or The programming controller (PLC) acts as the motion controller for the experimental system. The numerical control system unit is designed with compatible interfaces for different motion controllers, so that the user can replace the numerical control unit of the experimental system under the premise of minimal overhead. These compatible interfaces are designed with strict electrical protection circuitry to prevent students from damaging the system controller during the lab due to improper operation.

Students around the CNC system unit can carry out software design experiments. On the basis of mastering the programming techniques of different controllers, students can use the experimental teaching courseware, software interface (API) or other industry operating software to realize the input and output (I/O) control programming operation of the motion controller.

2. Drive experimental unit

The unit can be equipped with a stepper/servo motor driver and an AC variable frequency drive operator panel. After the student completes the corresponding driver control electrical circuit design and the corresponding electrical circuit connection, the manual operation of the corresponding driver in the driver unit can be completed through the experimental unit panel. Students can use this experimental unit to understand the working principle and engineering application methods of the drive, and to learn more about the speed or position closed-loop control process of the motion system and the related electrical characteristics of the control signals.

The manual/automatic switching function enables the drive principle experimental unit to accept control signals and control commands from the numerical control unit on the basis of the manual control of the drive. In this unit, a system monitoring circuit is also installed, which can transmit the numerical control system control signal and the system operation detection signal to the software courseware and monitoring software in the computer in real time, and the student can dynamically observe the running state of the system on the computer for deep understanding. Control the working process of the system.

3. Machine control unit

This unit provides students with a simulated environment for electrical operation of the machine. The unit panel is equipped with a variety of switches and indicators of various specifications. Students can understand the electrical principle of the milling machine and perform necessary electrical configuration on the panel terminals to complete the tool magazine, spindle shift, tool holder, limit, etc. Programming of various machine tool electrical control functions. This unit is connected to the universal input/output (I/O) interface of the CNC unit via an interface with electrical protection.

4. Servo drive unit

This unit completes the drive function of the motor in the CNC system. Thanks to the universal compatible interface design, the servo drive unit can be connected to the drive principle experimental unit or directly to the CNC unit. Teachers can choose different configurations according to the needs of the teaching content, or add different functional units at any time when there is an upgrade requirement. The operator interface of all devices has been reinforced to prevent students from being damaged during repeated operations.

5. Motor unit

This unit is the simulation part of the controlled object in the CNC system. In order to enable students to intuitively understand the working process of the CNC system and the in-depth understanding of the control program, each servo motor is equipped with a rotary dial. Students can observe the rotary scale of the dial during operation and debugging procedures to calculate the corresponding Processing journey.

6. XY motion platform

In the NC interpolation principle verification experiment or G code program experiment, the numerical control technology experiment system can be configured with XY motion platform, and the pen holder with program control automatic lifting can meet the needs of recording the experimental program trajectory. Each axis of the motion platform is equipped with a magnetic Hall device for detecting the center of the shaft and the extreme position. The motion platform is controlled by a servo drive unit, and its feedback signal can be connected to the motion principle experimental unit.

7. Experimental courseware

The control software mainly includes three parts: experimental courseware, software interface and man-machine interface.

The experimental courseware is the experimental project guidance software for the experimental system. It can lead the students to complete the relevant experimental content, and display the working status of the system in real time during the experiment, providing rich experimental data for students' perceptual understanding and in-depth analysis of the working principle of the system.

8. Power control unit

This functional unit is the main power supply loop of the system. It is placed on the system mesh board to effectively control and detect the three-phase five-wire power supply line. It is equipped with leakage protection and phase loss protection circuit. The device protection circuit operates automatically in the event of leakage, short circuit, phase loss and neutral line disconnection. Students can also train the extended relay logic control on some of the functional units on the mesh board. There is a system emergency stop button in the system, which can cut off the main power supply circuit and avoid damage to students and equipment when the program or equipment is abnormal.

Name of the work: Modular CNC technology experimental device

Completed by: Tianjin University