Article keywords: elevator, fragmentary, publishing house, Beijing, initiative, controller, technology, door closing, industry, tractor.
Text:
Graduation Design (Thesis) Opening Report
First, the method and significance of topic selection:
In modern society, elevators have become an indispensable means of transportation. The existence of elevators is making the traffic of every tall building more convenient. The development of elevator control technology has mainly gone through three stages: relay control stage, microcomputer control stage and field bus control stage. At present, elevators should use programmable controller (PLC), which is convenient to require functional changes, simple in programming, less obstacles and low in noise. Convenient maintenance, energy-saving and labor-saving, strong anti-interference ability, and small floor space of the control box. When the passenger enters the elevator, press the floor button, and the elevator door will be closed automatically, and the following operations will be controlled piecemeal: according to the position of the car and the number of floors where the passenger is located, determine that the car is biased to ensure that the car slows down when lying flat. Park the car on the selected floor; At the same time, with the cry of the floor, stop and open and close the door actively. In addition, there should be signal lights inside and outside the car to show the elevator running deviation and the number of floors. With the rapid development of economy, microelectronics technology, computer technology and active control technology have also developed rapidly. AC frequency conversion control technology has entered a new era, and its application is more and more extensive. Elevator is a kind of linear traffic thing in modern high-rise buildings, and its concept requires bumps, stability and height. With the continuous improvement of people's living standards, the requirements for elevators have also increased accordingly, and elevators have developed rapidly. The general development trend of elevator pre-sale is mainly manifested in the following aspects.
First, the elevator drive technology
The control technology of (1) variable frequency speed regulation has been widely developed and applied, and its control type has gradually developed from GTR to GTR and IGBT, making its control more perfect and progressive.
(2) Linear motor is adopted to drive the elevator, which makes the driving mode of the elevator break through.
Second, the high-speed elevator which is controlled by DC SCR gearless drive is gradually developing to VVVF gearless drive control, because the latter has the characteristics and advantages of energy saving and piecemeal miniaturization. Elevator control technology
The application of (1) microcomputer network control technology makes the piecemeal reliability higher and the function processing more flexible.
(2) Using surface mount technology and large-scale ASIC circuit to reduce the printed board area and improve the reliability of electronic circuits.
(3) Fuzzy logic and expert segmentation are applied to elevator group control distribution to improve the efficiency and accuracy of group control segmentation.
(4) Accept the intelligent power module to form the intelligent control system of the elevator.
(5) Accept high-digit CPU, enhance elevator signal processing function and speed up signal processing.
(6) Constantly increase and expand various selection functions of elevators. At present, there are more than 60 to 70 kinds of elevator functions to choose from, which makes the modeling color of elevator car diversified, artistic and personalized, and integrates with the building.
Third, the elevator speed.
With the development of high-rise buildings and elevator basic technology, the running speed of elevators is gradually developing to high speed. At present, the highest speed of elevators in the world has reached 12.5m/s, which was developed and put into market by Mitsubishi Corporation of Japan and put into use in Japan.
Four, the technical aspects of the traction machine
The gear traction machine is gradually developing from the traditional worm gear transmission to planetary gear rotation, which is beneficial to reduce the size of the traction machine, improve the bearing capacity and transmission efficiency, and make it develop at a high speed.
Most elevators made in China are controlled by relays and PLC. PLC is a special computer for industrial active control, which is essentially a computer control mode. Like ordinary microcomputer, PLC uses general or special CPU as word processor to complete channel (word) operation and data storage, and bit processor (Boolean processor) to perform point (bit) operation and control. PLC control generally has the characteristics of high reliability, easy operation, easy maintenance, simple programming and flexibility. This time, it is envisaged to complete the PLC control mode, study and analyze the logical relationship of the elevator, and thus complete the control. Because elevator control is fragmented and mixed, we accept the idea of four people divided into modules. The modules I want to imagine are the main drag control and the active door opening and closing control.