The Design Of Tire Crane Excitation Control System

Excitation control system, as a main part of tire crane, mainly to drive and control DC motor of lifting and luffing mechanism, affects the safe and steady operation of motor and tire crane. The existing analog excitation control system can’t meet the demands(reliability, stability, flexibility and economy) for the running DC motor, because of its start and speed control model is resistors in series which leads to large start current and small and smoothly speed control, except for more energy consumption, noise and bulky. For the transformation of excitation control system for medium-sized tire cranes and new projects, and the trends of excitation control technology and excitation control algorithm, a tire crane digital SCR excitation control system based on ATmega128MCU and IPM (Intelligent Power Module to driver) is designed. The main content is as follows:Firstly, the paper introduces the development state and advantage of the DC motor excitation control system, analyses the problems existing in crane excitation control system, discuss the basic concepts and ideas of the common control algorithm. The basic principles and methods of the excitation control system are established based on the analysis of excitation control system and DC motor’s structure and working principle.Secondly, establish the mathematical model of the dynamic work of the series excited DC motor. Motor speed and current feedback are combined with PID control algorithm to form dual closed-loop PI excitation control system. Then it is simulated by MATLAB and the results are analyzed. After that, according to ATmegal28is characterized by high-speed, low power, pipeline structure, which is made by Atmel Corporation in recent years in USA, and the chip integrates a complete AD sampling port and PWM output port, a new tire crane digital excitation control system based on ATmegal28microcontroller is designed. Adoption of this chip greatly simplifies the hardware structure of the excitation control system, improves the anti-jamming capability and reliability of the excitation control system. Finally, the paper describes the design method of the hardware and software used in the excitation control system, presents some schematic diagrams of hardware, programs and the flow chart of software.Field test results and actual usage show that the tire crane excitation control system based on ATmega128has the characters of simple hardware structure, easy to use, high reliability, good control performance, cost-effective high and etc. It has a good market prospects for its key performance indicators at or better than the similar products.