- Topic overview:
Overview of the manipulator:
The manipulator is a new type of device developed in the mechanized and automated production process. In recent years, with the wide application of electronic technology, especially electronic computers, the development and production of robots has become a new technology that has rapidly developed in the high-tech field. It has further promoted the development of manipulators, enabling them to better realize Organic combination with mechanization and automation.
Although the manipulator is not as flexible as the human hand at present, it has the characteristics of continuous repetitive work and labor, no fatigue, no fear of danger, and greater strength than human hands in grabbing heavy objects. Therefore, the manipulator has been valued by many departments and is becoming more and more popular. has been widely applied.
Manipulators are usually used in places with complex actions to replace human repeated operations, thereby saving human labor. Ordinary relays are often used in electrical and assembly line controls with simple actions due to their size and interface limitations. High reliability, strong anti-interference ability; simple structure and strong versatility of the control system; simple programming, convenient use and maintenance; convenient combination, strong function, wide application range; small size, light weight, low power consumption, etc. are widely used In the occasions where the control action of the manipulator is complicated, this design is based on PLC control to realize various actions of the manipulator.
For example:
(1) Loading and unloading of workpieces processed by machine tools, especially on automatic lathes and combined machine tools.
(2) It is widely used in assembly operations. It can be used to assemble printed circuit boards in the electronics industry. It can be used in the machinery industry
for assembling parts.
(3) It can work in a working environment with poor working conditions and monotonous and repetitive fatigue, so as to replace human labor.
(4) It can work in dangerous places, such as loading and unloading of military products, handling of dangerous and harmful materials, etc.
(5) Development of the universe and the ocean.
(6) Research and experimentation in military engineering and biomedicine.
How the robot works:
In addition to the multi-step feature, the electrical control system of the manipulator also requires operation modes such as automatic control and manual control. The choice of working mode can be easily indicated on the operation panel. When the knob is turned back to the origin, the system automatically returns to the upper left corner and stands by. When the knob is turned to automatic, the system automatically completes each step operation, and the action is cyclic. When the knob is turned to manual, each step must be pressed to realize the step button. This design only designs single-step and continuous control according to the requirements.
- Design tasks and requirements:
1. The manipulator is at the original position, press the start button, the conveyor belt B starts to run, and the manipulator starts to rise from the bottom right to the position. 2. The manipulator rises to the position of the upper limit travel switch. After pressing the travel switch, the rising action ends and the manipulator starts to rotate leftward. 3. The manipulator turns left to the position of the left limit travel switch. After pressing the travel switch, the left-hand movement ends and the manipulator begins to descend. 4. The manipulator descends to the position of the lower limit travel switch. After the travel switch is activated, the descending action ends, and the conveyor belt A starts. 5. Conveyor belt A advances one item away from the manipulator, then stops the manipulator and starts to grab the item. 6. The manipulator grasps the object, and the degree of grip is controlled by the travel switch on the finger. After the grasping is over, the manipulator starts to rise. 7. The manipulator rises to the position of the upper limit travel switch. After pressing the travel switch, the upward movement ends, and the manipulator starts to rotate to the right. 8. The manipulator rotates right to the position of the right limit travel switch. After pressing the travel switch, the right rotation ends and the manipulator begins to descend. 9. After the manipulator descends to the position of the lower limit travel switch and presses the travel switch, the descending action ends, and the manipulator begins to put down the items in its hand. 10. The manipulator puts the object after a proper delay, the object is placed, and a working cycle is completed.
3. Scheme design:
System general composition diagram or function diagram, software flow chart
1. PLC I/O address allocation table
| input device |
Enter point number |
output device |
output point number |
| start up button |
X0 |
Conveyor belt A motor |
Y1 |
| Left limit switch |
X1 |
Conveyor belt B motor |
Y2 |
| Right limit switch |
x2 |
Ascending/descending single acting cylinder |
Y3 |
| upper limit switch |
X3 |
Left-handed/right-handed single-acting cylinder |
Y4 |
| lower limit switch |
X4 |
Gripping/releasing single-acting cylinders |
Y5 |
| Advance item distance detection |
X5 |
||
| Finger tightness detection travel switch |
X6 |
- PLC I/O hardware wiring diagram (drawn with electronic CAD software)
Figure 1 I/O hardware wiring diagram of industrial manipulator
3. Draw the SFC diagram (draw with Mitsubishi or Siemens programming software, the screenshot is clear)
Figure 2 SFC diagram of industrial manipulator
4. Draw the ladder diagram (draw with Mitsubishi or Siemens programming software, the screenshot is clear)
Figure 3 Ladder diagram of industrial manipulator
5. Instruction list program (screenshot is clear)
Figure 4 Instruction table program of industrial manipulator
4. On-machine debugging program:
Press X0 to start the device, Y2 to start the motor of the conveyor belt B, and the conveyor belt B starts to run, Y3 to start the ascending/descending single-acting cylinder, and the manipulator starts to rise, X3 means the manipulator rises to the position of the upper limit travel switch, after pressing the travel switch, the ascending action ends , Y4 starts the left-handed/right-handed single-acting cylinder, and the manipulator starts to turn leftward. X1 means that the manipulator rotates leftward to the position of the left limit travel switch. After pressing the travel switch, the left-hand rotation ends, and the Y3 manipulator starts to descend after reset. X4 means that the manipulator descends to the position of the lower limit travel switch. After the travel switch is activated, the descending action ends. Y1 starts the motor of the conveyor belt A, and the conveyor belt A starts. The conveyor belt A advances the distance of one item (X5) towards the manipulator and then stops, and the manipulator starts to grasp the object ( Y5), the manipulator grasps the object, and the degree of grip is controlled by the travel switch X6 on the finger. After the grasping is completed, the manipulator starts to rise, and the manipulator rises to the position of the upper limit travel switch. After pressing the travel switch, the upward movement ends, and the manipulator starts to rotate right. The manipulator rotates right to the position of the right limit travel switch. After pressing the travel switch, the right rotation action ends, and the manipulator begins to descend. After a proper time delay, the loading ends, and a working cycle is completed.
5. Conclusion and experience:
Through this course design, I have a better understanding of the design and application of PLC, and have a deep understanding of the control knowledge of PLC products. Through the combination of theory and practice, the ability to observe, analyze and solve problems has been further improved. In order to cultivate high-quality compound talents who can actively adapt to the needs of socialist modernization. Using the learning results and applying the theory to practice, I have cultivated my ability to comprehensively apply the theoretical knowledge of the programmable controller design course and other courses and apply the practical knowledge of production to solve practical engineering problems, laying a solid foundation for future study and work. Base.
6. References
[1] Tang Yin, and Liu Yang. "Overview of Industrial PLC Control System Design." Enterprise Herald.15(2012):287. doi:10.19354/j.cnki.42-1616/f.2012.15.202.
[2] Qin Tao. The application of PLC in the automation control of industrial manipulators [J]. Integrated Circuit Application, 2022, 39 (04): 164-165. DOI: 10.19339/j.issn.1674-2583.2022.04.069.
[3] Jin Wei. Design of Industrial Manipulator Control System Based on PLC [J]. Digital Communication World, 2019(04): 257.
[4] Li Shiqiang, Wang Xia. Design of Industrial Manipulator Automation Control System [J]. Automation Technology and Application, 2022, 41(10): 1-3+14. DOI: 10.20033/j.1003-7241.(2022) 10 -0001-04.
[5] Du Lingxin, Yao Chunge, Lin Wenjun. Design of Industrial Manipulator Based on PLC Control [J]. Internal Combustion Engines and Accessories, 2019(07): 219-221. DOI: 10.19475/j.cnki.issn1674-957x.2019.07.113.