Design and development of manipulator control syst

Design and development of the manipulator control system of CRT production line

Sanjin company introduced a complete set of manufacturing equipment and technology for producing monochrome tubes from Japan in 1989. The project is equipped with 10 robots to form a full-automatic production line. Problems caused by equipment aging occur frequently, which has a great impact on the smooth progress of production. In addition, most of the electronic components required to maintain the equipment have been discontinued. In view of this, the company proposed to transform it. Since most of the problems of the manipulator are concentrated in the control system, and the problems related to machinery and motor can be completely avoided through regular maintenance of the equipment, the basic idea of the transformation is to retain the mechanical part of the manipulator, DC brush servo motor and photoelectric incremental encoder, redevelop the control system of the manipulator, and the newly developed control system must have a high degree of reliability and stability, At the same time, it has the automatic switching function of multiple varieties

hardware configuration

because the control system of the old manipulator (the manipulator before transformation) uses the common PLC controller and Z80 microprocessor to work together to realize the motion control, system management and detection of the manipulator. Therefore, the structure is complex and difficult to maintain. With the development of PLC technology and the emergence of process PLC, the above problems can be solved in a more simple way. Because this controller has the following characteristics:

(1) it has analog quantity/digital link: input and output of the amount of new chemical materials listed in the directory

(2) control of multi axis servo motor

(3) rs232/rs485 program transmission interface

(4) real time multitask parallel processing function

(5) good man-machine interface, etc

at the same time, because process PLC programming language sympas uses high-level text language, the programming and reading of the program are more intuitive. According to the requirements of production and process technology, the nano-b control module in process PLC is finally selected as the main controller to realize the control of the manipulator. At the same time, the hardware structure of the whole manipulator control system is basically formed, and the block diagram of the control system is shown in Figure 1:

this control system is a full closed-loop position control system, in which the main function of nano-b controller is to store control programs, detect peripheral signals, and send control instructions to external devices. N-sv1 is an X-axis servo controller, which mainly accepts the control command of nano-b, converts it into the corresponding command signal and control signal to control the servo driver, and receives the feedback signal of the servo driver (the functions of n-sv1, n-sv2, n-sv3 are the same). X driver is an X-axis servo driver, which mainly receives the control signal and speed command of n-sv1 controller and the feedback signal of motor encoder. At the same time, on the one hand, the motor reaches the set speed through f/v conversion and comparison, on the other hand, the feedback signal of the encoder is uploaded to the n-sv1 controller. (the functions of X driver, y driver and Z driver are the same). M is the servo motor and E is the encoder of the motor

software implementation

modular programming is the most commonly used method in programming. It not only makes the reading of the program more intuitive, but also makes the programming and debugging clearer. The control system software is composed of: main program module, origin debugging module, product selection module, automatic operation module and manual adjustment module

1. The main program has another module

which includes the initialization of the controller; Monitor the control button of the operation screen and realize its function; Processing of upper limit alarm subroutine

2. Origin debugging module

it mainly completes the function of 3-axis automatic origin finding and soft limit setting

3. The product selection module

reads and judges the value of the product selection register, sends the corresponding product parameters to the specified register, and switches the selected product parameter screen to the current screen of the product parameter button

4. The automatic operation module

realizes the control and counting function of the whole movement process of the manipulator

5. manual adjustment function

it includes the rapid positioning of the manipulator position under manual conditions, and the fine adjustment and storage of the position at different speeds. Among them, the automatic operation module is the core to realize the motion control of the whole system. The software program flow chart is shown in Figure 2

man machine interface

man machine interface adopts touch screen control system and is realized by adp3 software. The whole interface is displayed in Chinese, making the operation more simple and clear

system application

field application debugging is to verify whether the control system achieves the desired effect of the designer. It is more important to verify whether the software and hardware can operate stably and reliably under various interference conditions on site. It is not only an indispensable part of the whole design, but also an important way to continuously improve and improve the performance of the system. Through field application debugging and a period of operation, it can be said that this system has reached our design requirements. And it has exceeded our original design idea in some aspects. The advantages of the system can be summarized as follows:

(1) the switching time of different products is reduced from more than ten minutes to a few seconds, which has made a significant contribution to improving productivity

(2) the improvement of system integration makes the structure of the control system simpler and more compact

(broken by 3-point static zigzag load 3) the full Chinese man-machine interface and instructional operation design of the control system make the training of operators easier

(4) the new product counting function can enable relevant personnel to timely grasp the input-output ratio of each process related to the manipulator

(5) the control system adopts modular design in structure, and different modules provide rich information prompts, which can make it easier for equipment maintenance personnel to master the operation status of the equipment

(6) the design of fast positioning function makes it more convenient and fast for operators to fine adjust the position

(7) the upper limit alarm function can minimize the damage of the glass shell and protect the forearm of the manipulator

(8) multi level password protection function enables the operator to operate according to his authority, so as to reduce the occurrence of human accidents. (end)