Development Of Embedded Elevator Control System Based On ARM Technology

Since the world's first elevator was made by Otis America Corporation in 1887, the elevator has become an essential instrument in people's daily life, as a vertical take-off and landing of transport equipment. Along with the economic development and the springing up of high-rise buildings, the function and types of elevator is more diverse now and the stability, safety, comfort, and operating efficiency of elevator has put forward higher requirements.Elevator control system is the core of elevator technology which combines the lift's mechanical components organically toachieve the complexed functions, stable and efficient operation of the elevator. With the rapid development of electronic technology, elevator control system has undergone the course of development: relay control, programmable logic device control, intelligent computer control. This paper summarizes the current elevator control system, and designs a collective selective elevator control sysytem based on the ARM technology and the industrial fieldbus CAN(Control Area Network) in which VVVF frequency speed control technology is used. The control system can be equipped with different kinds of inverters and motors, including asynchronous motor and permanent magnet synchronous motor. It adapts that total floors are smaller than 64 and elevator speed is smaller than 4m/s. The control system we designed have been successfully used in domestic and South Africa elevator projects, etc.This paper outlines the control strategy of the embeded elevator control system and elaborates the hardware structure and software design of the master controller, whose core processor is LPC2378 based on ARM7 architecture. Motor speed control is the key of the elevtator control technology, so the mathematical model of the the elevator speed curve is setted up, and a caculated method is proposed for generating the speed curve in accordance with the setted time parameters and floor distances in the paper. Improving elevator run-time comfort and operating efficiency is our target. In order to optimize the start-up comfort, the fuzzy control technology in the application of load torque compensation is discussed. Based on describing the CANOpen protocal in details, a CAN application protocal inheritted from CANOpen is also designed which realizes the real-time and reliable communication between all controllers(Master controller, Floor controller and Car controller ).