Development of a distributed elevator control system based on the microcontroller PIC 18F458

This paper presents the distributed control system for elevators (DECS). Based on the characteristics of the today installed elevator systems, the electric traction elevator has been chosen for this paper. Conventional elevator control systems (ECS) have several disadvantages compared to modern control systems (large number of cables, safety issues, etc.). An alternative to conventional ECS is the DECS. A DECS based on the CAN (Controller Area Network) protocol is presented in this paper. The presented ECS consists of three modules: CU Elevator (CU - Control Unit), CU Cabin, CU Floor. The mentioned modules, control principles and implementation methods based on the PIC 18F458 microcontroller are presented in detail. A description of the CAN protocol design with message scheduling on the bus is given. Messages with an 11 bit identifier without a data field have been used for the distributed control system synthesis. The time analysis of bus availability/traffic demonstrates the adequacy of the distributed control system Based on the defined messages and 5 presented modes of operation, an algorithm of operation has been formed for every control system module. Finally experimental results are presented that have been obtained from a developed CAN based elevator control system. The conducted tests have confirmed the functionality of the elevator control system.