Application Of The Position Detection Of Magnetic Grid Device In Elevator Car

Elevator generally use a combination of photoelectric switches and rotary encoder to measure the position of the car,in normal use,it basically meets the requirements of elevator stopping accuracy.But the car position is a relative calculation value,when the elevator wire rope slip or suddenly power loss,the elevator is easy to lose the car position,the treatment measures at this time is to control the elevator down slowly,until the bottom limit switch,so as to determine the car position.Therefore,a special device for car position detection is required to ensure that the real-time absolute position of the car can be measured to improve the safety performance of the elevator.In this paper,an application scheme is designed to detect the absolute position of the elevator car through the LIMAX33 magnetic grid device,so as to realize the detection of the absolute position of the car and improve the safety performance of the elevator,the contents of this paper are as follows:(1)According to the working principle of the LIMAX33 magnetic grid device,the magnetic tape is vertically arranged from the bottom of the elevator shaft to the top of the shaft,and any position on the magnetic tape has a unique corresponding magnetic signal code.The magnetic grid sensor is fixed on the outside of the elevator car,and the magnetic signal code on the magnetic tape is read through the hall effect principle,so as to realize the detection of the absolute position of the car.At the same time,the magnetic grid device also provides a very reliable safety protection function to improve the safety of the elevator.(2)In the part of electrical principle,the power and communication circuit,safety monitoring circuit,door lock monitoring circuit and other electrical circuits between the magnetic grid scale device and the elevator main control system are designed.According to the CANopen communication protocol of the magnetic grid device,the communication and function parameters are set,and the lift shaft floor learning function,re-leveling bridge function,unintended car movement protection function and deceleration control function are completed control flow design with equal function(3)Through laboratory and elevator test,the functions of magnetic grid device,such asposition detection function,elevator shaft floor learning function,re-leveling door bridging function,terminal limit function,unintended car movement protection and deceleration control function are verified.The test results show that the leveling accuracy of elevator flat floor meets the design requirements,and the protection function is safe and reliable.In this paper,the detection of the absolute position of the elevator car are realized through the magnetic grid device.There is no risk of position loss.The floor of the elevator is accurate and reliable.and the magnetic grid device provides the protection function independent of the elevator system,which further improves the safety performance of the elevator.The magnetic grid device can save many traditional elevator components and the cost of installation and maintenance.Its non-contact detection is more suitable for elevator shaft environment,with the advantages of anti oil and dust.It has important application and market value to use the magnetic grid device as the detection of the absolute position of the elevator car.