The Measurement Of Real-time Position Of Elevator Car Based On Infrared Coding

Position detection of the elevator car is of great importance to its control.The elevator controller determines how the elevator moves according to the location and speed information provided by the position detection system.Linear absolute position encoders have been widely used in elevator position detection.As modern buildings become higher and higher,there is a growing demand of miniaturization and large measuring range for elevator encoders.Therefore,it is urgent to innovate coding theory to develop encoders that meet the market demand.First of all,a linear double track absolute position coding method is proposed in this paper.We first proposes a noval multi-channel detecting method based on uniform-distribution encoding.Then,a linear double track absolute position coding method is present via combining the m-sequence and single-track Gray code.Finally,a 19-bit linear double track absolute position encoder is developed based on the theory of absolute position code.Secondly,a 19-bit linear double track absolute position encoder is developed according to the coding method.The encoder is divided into hardware and software parts.The hardware part consists of STM32F103RCT6 microcontroller,infrared detection module,acceleration module,CAN(Controller Area Network)communication module,and power module.The software part includes position detection module,speed detection module,acceleration detection module,CAN protocol,and various safety functions.After all,we comprehensively inspect the function of the encoder.We used the oscilloscope,CAN analyzer and other electronic instruments to inspect our encoder.Furthermore,we used highspeed elevator as a comprehensive experimental platform to inspect our encoder.Simultaneously,we further improved the software design of the encoder and reduced the size of the encoder according to the testing results.The coding method proposed in this paper overcomes the shortcomings of the multi track coding method and the single track coding method.The encoder developed based on the coding method can meet the market’s demand for miniaturization and larger measurement range.