Research And Design Of Automatic Rope Harvesting Mechanism Of Elevator Load Replacement System

Elevator is an important transportation equipment in modern high-rise buildings.Its superior performance and control system are directly related to the safety of users.The special equipment inspection and testing institutions need to carry out load tests on elevators in order to ensure the safe and stable operation of elevators.In order to reduce the labor intensity of load weights(more than one ton)handled by inspectors,Jiangsu University has developed a replacement system for elevator load test.When the elevator is moving upwards,it is loaded by wire rope towing the car.At the end of the load test,the steel wire rope should be retrieved to prepare for the next load test.In this paper,a new type of automatic rope harvesting device is designed for the elevator load replacement system to ensure the smooth loading of the load in the elevator test.The main research contents and results are as follows:1.According to the performance requirement of the lifting process in the elevator load test,the concept of constant tension control in the process of wire rope recovery has been put forward.At the same time,the scheme of wire rope collection based on constant tension control on the wire rope has been established and the overall structure of the wire rope collection device has been designed.In order to solve the problem of orderly arrangement in the process of wire rope recovery,the optimum design scheme of automatic wire rope retrieving device has been put forward and the mechanism of rope retrieving device has been improved.Meanwhile,the performance of rope retrieving device has been tested and analyzed.By using the steering function of the steering gear,the mechanical arm has been designed to realize the automatic steering of the handle for the state transition of the rope arranger.It can solve the problem of the state transition of the rope arranger in the receiving and releasing ropes.2.The measurement and control system of automatic rope harvesting device has been studied and designed.By studying and analyzing the composition and working principle of AC asynchronous motor,the mathematical model of variable frequency speed regulation has been established and the simulation test has been carried out by MATLAB.The test results showed that the induction motor controlled by frequency conversion speed regulation had the characteristics of fast speed response,small torque fluctuation and small overshoot.Fuzzy-PID controller has been designed for constant tension control of wire rope in the process of rope harvesting.Compared with traditional PID control method,the adjustment time is shortened by 80%,and the overshoot is reduced by 20%.It satisfies the control requirement of the rope harvesting motor.3.According to the requirement analysis of monitoring performance in the process of automatic rope harvesting,a remote monitoring scheme has been established and a monitoring system based on Android platform has been built.The GPRS module has been debugged,and the information transmission between the server,the client and the GPRS module has been realized by using the Socket communication mechanism.A fully functional client APP and a good man-machine interface have been designed,including the login registration interface,the display bar of tension value on the wire rope and the control button of the rope harvesting motor.It realizes the visualization and controllability of the automatic rope harvesting process.4.The wireless communication experiment has been carried out in the elevator well to test the transmission performance of LoRa radio module in the static and moving state of the elevator.At the same time,in order to improve the accuracy of the collected data,the A/D sampling has been filtered and the calibration test of the tension sensor has been carried out.5.The test platform of the automatic rope harvesting device has been built and the software and hardware tests have been carried out.The test results show that the automatic rope-taking device can automatically adjust the speed of the rope-taking motor according to the tension of the wire rope and achieve good functions of ropetaking and rope-arranging.It can satisfy the performance requirement of automatic rope collection of elevator load replacement system.