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With the development of modern high technology, residential buildings and office buildings are gradually developing into high-rise buildings. Elevator is an indispensable vertical transportation tool for high-rise buildings such as high-rise hotels, shops, houses and multi-storey warehouses. 1889, Otis Elevator Company of the United States launched the world's first electric elevator, and it was successfully installed in the male tower in new york in the same year. With the increasing scale of buildings and higher floors, higher requirements are put forward for the static and dynamic characteristics of elevators such as speed regulation accuracy and speed regulation range. Because the traditional elevator operation logic control system adopts relay logic control circuit. Using this control circuit, there are some shortcomings, such as easy failure, inconvenient maintenance, short service life and large space occupation. From the perspective of technological development, this system will be gradually eliminated.
At present, the elevator operation logic control system composed of programmable controller (PLC) or microcomputer is developing rapidly. Programmable controller is the product of the combination of microcomputer technology and relay conventional control technology. It is a new controller developed on the basis of sequence controller and microcomputer controller. It is a special computer with microprocessor as the core for digital control. It has good anti-interference performance and adapts to the harsh environment of many industrial control sites, so now the elevator control system is mainly controlled by programmable controller. However, due to the strong pertinence of PLC, each PLC is designed according to a device, so the price is more expensive. Single-chip microcomputer is quite cheap. If the anti-interference function is improved, it can completely replace PLC to control industrial control equipment. Of course, MCU is not as targeted as PLC, so the control system designed by MCU can be constantly modified and improved with the update of equipment, and the equipment upgrade can be realized more perfectly.
Elevator control system is a complex large-scale system. In the decades since the birth of computer, relay control system has made great contributions to the development of elevator control, but there is still an essential gap with PLC in performance. With the continuous development of science and technology, I think the single chip microcomputer control system can quickly solve the anti-interference problem and become a convenient and effective elevator control system.
Due to the limitation of time and ability, there are inevitably many omissions and deficiencies in the design process. Please criticize and correct me, and I will try my best to make a perfect graduation project.
catalogue
Directory 1
Quote 2
Chapter 65438 +0 Thread Theory 3
1. 1 elevator development 3
1.2 classification of elevators 4
Chapter II Scheme Comparison and Determination 6
2. 1 scheme selection 6
2. 1. 1 Advantages and disadvantages of elevator relay control system 6
2.1.2 Features of PLC control system 6
2. 1.3 characteristics of elevator frequency conversion control 7
2.2 the choice of single chip microcomputer control scheme 7
2.3 Selection of Inverter 8
Chapter III Hardware System Design 10
3. 1 hardware structure diagram 10
3.2 schematic diagram of system hardware 10
3.3 Principle of 89C51Single Chip Microcomputer and Design of its Peripheral Circuit 5438+00
3.3. 1 89C5 1 Principle and Structure of Single Chip Microcomputer 5438+00
3. 3. 2 14 MCU peripheral circuit design
3.4 Design of input module 18
3.4. 1 latch 74LS373 and its extended function brief introduction 20
The photoelectric sensor 20
3.4.3 Basic application circuit of KC778B infrared sensor 2 1
3.4.4 Acquisition of input signal 22
3.5 Design of Output Module 24
3.5. 1 DAC0832 function brief introduction 25
3.5.2 Brief introduction of frequency converter function 26
3.5.3 Brief introduction of LED driver functions 29
The output of the control signal 32
Chapter IV System Software Design
4. 1 main program flow chart 34
4.2 Flow chart of reading information and displaying subroutine 37
4.3 Delay jitter subroutine 37
4.4 Set the target layer subroutine flow chart 38
4.5 Motor Drag Subroutine Flow Chart 39
4.6 elevator passenger subroutine flow chart 40
4.7 Interrupt Service Flowchart 4 1
Summary and prospect 42
Acknowledgement 43
Reference 44
Appendix: 45
Appendix a electrical schematic diagram 45
Appendix B Foreign Language Documents and Their Translation 46
Appendix c main references and their abstracts 50