| In recent years,with the rapid economic growth,domestic subway construction ushered in a development climax.Shield tunneling method can be widely used in urban subway construction because of its fast construction and safety.Shield transport flatbed truck,as a supporting horizontal transport equipment for shield tunneling,affects the efficiency of engineering construction to a certain extent.At present,the domestic shield transport flatbed trucks are powered by centralized power,that is,a single high-power motor with a head is used to centralize the traction force,and the short-distance transmission is powered by battery.This kind of shield-driven flatbed has some shortcomings,such as high failure rate,long charging time and heavy battery pack.This paper designs a power distributed shield transport flatbed vehicle based on Ethernet communication.The power of the shield transport flatbed vehicle is dispersed on each marshal and powered by super capacitive energy storage system,while the front of the vehicle only provides forward and backward operation.The main work is as follows:(1)The overall control scheme of the shield transport flatbed is determined.The traction power of the shield transport flatbed truck is calculated to determine the type of AC motor and reducer.This paper briefly introduces the working principle of super capacitor,calculates the capacity of super capacitor,determines the working voltage and series-parallel connection scheme of super capacitor.(2)The main controller,on-board controller and Ethernet communication hardware circuit of shield transport flatbed vehicle are designed.The main controller includes switching signal acquisition circuit,acceleration/braking signal acquisition circuit and LCD display circuit.Vehicle controller includes optocoupler isolation circuit,motor drive circuit,current sampling circuit and voltage sampling circuit.Ethernet communication is mainly the design of Ethernet interface circuit.(3)The principle of direct torque control is introduced,and the simulation of direct torque control of induction motor is completed.On the basis of the stable operation of a single motor,the genetic algorithm is used to optimize the PID parameters in the deviation coupling control to realize the multi-motor synchronous control in the distributed power system,and compared with the traditional deviation coupling control.The results show that the deviation coupling control based on genetic algorithm PID can effectively reduce the synchronization error among the motors,and the convergence speed is fast.(4)Using modular programming idea,the software program of main controller,vehicle controller and Ethernet communication is designed,and an experimental platform is built to test the hardware circuit. |
