Design of Distributed High Precision Temperature Control System Based on CAN

摘要

This paper introduces a type of temperature control system base on CAN (Controller Area Network) bus, and describes the design of field controller with multiple users. The field controller connects to the host computer via CAN bus to build a distributed high-precision temperature control system based on CAN interface. The system consists of host computer, CAN adapter, and intelligent nodes with networked bus interface. The temperature controller is made up of single chip computer of AT89C52 with communication rate of 125Kbit/s. The technical characteristics and measurement solution of hot-junction of every type of temperature sensor are analyzed. The temperature T is worked out through quadratic parabola interpolation. In addition the super-adjustment and long duration oscillation is removed via integral separation. The acquisition of parameter P and I and D of the PID (Proportional-Integral-Differential) adjuster and the self-configuration method and its benefits are presented too. Then the simulation and application are performed. This system has been used in the thermal network control circuit of thermoelectric factory, and increases the running efficiency, so it can be widely used in Industry field.