Research of detecting lift car position by the photoelectric sensor Si1120

This paper presents a new device which can detect the lift car position by the photoelectric sensor Si1120. Microcontroller ATmega16 is used as the main controller of this new device. The Si1120 can output PWM wave when sense the infrared light. According to the strength of the infrared light reflected from the tailgate on each floor, the ATmega16 receives the PWM wave of different width. The distance is different between the device and baffle on each floor, so the device can detect the elevator floor position. The device can work when just fixed on the lift car, so the precision of installation is low and with easy maintenance. The experimental results indicate that the system´s real-time, accuracy and reliability basically meet the control requirements. This new type of detector has a certain practical value and great application prospect.