Design And Implementation Of Elevator Core Controller Based On Embedded System

By analyzing the elevator control system and the current development trend, it is proposed that the elevator core controller with independent intellectual property rights be developed using embedded system technologies. The paper focuses on design and implementation of the elevator core controller based on embedded system.The paper analyzes the overall structure of elevator control system, setting elevator group control, remote monitoring, fault diagnosis, fault alarm and human-computer interaction (HCI) into an intelligent elevator core controller. The four components of embedded system are studied: the hardware platform, the hardware abstraction layer, embedded operating systems and embedded applications. Analysis and choices are made to build the hardware platform, the hardware abstraction layer and embedded operating systems of the elevator core controller. The task construct of embedded system, the choice of multi-process and multi-thread, the threads scheduling and threads synchronization mechanisms of Linux are thoroughly discussed, which gives strong support to construct the embedded applications of the elevator core controller.The paper focuses on hardware design and implementation of the elevator core controller. The hardware structure of the core board of the elevator controller based on AT91RM9200 is analyzed, and the external board is designed and implemented, which includes Ethernet module, RS232/Modem module, CAN communication module, digital input/output module, and HCI module. The role of complex programmable logic device (CPLD) in the circuit design is researched, as well as its design process.The paper focuses on software design and implementation of the elevator core controller. First, the overall structure of the embedded software platform of the elevator core controller is proposed, then the drivers of the controller hardware modules under Linux are researched. In view of the functional requirements of the controller, the software data flow diagram of a single elevator is designed. On this basis, the tasks of the elevator core controller are constructed, and the basic logic control functions using multi-thread method under Linux are implemented.Finally, a virtual test platform is built to test the software and hardware functions of the elevator core controller.