Design And Research Of Embedded PLC Based On A Certain Type Of Special Steering Gear Performance Test System

The steering gear can control the precise of the rotation angle,especially in the fields ofaviation,spaceflight,shipping and so on.The main operation mode of steering gear issendingapulse signal with changeable widthtomotorby steering gear controller,the control line transfer a pulse with desired duration to control rotation angle of steering gear.The performance parameters of each part of the steering gear controller are the important criteria of the steering gear control system,and the test is also an important part.Until now,the application of PLC technology in industrial production has been developed and mature.It is the mainstream controller of mechanical and electrical equipment in our country.With the rise and development of Internet of Things in recent years,PLC has a good adaptability to intelligent factories and industrial Internet of Things because of its simple docking and low technical requirements.Therefore,the architecture of PLC and Internet of Things has became a new trend of industrial automation.But most of the industrial PLC market is controlled by leading enterprises in the field of global electronic and electrical engineering,such as Mitsubishi,Siemens,Omron and Schneider.In order to overcome the traditional shortcomings of high cost and closed architecture,some companies developed embedded PLC at home and abroad were established.With the mutual penetration and combination of PLC,computer and embedded system,different embedded PLC products have their own characteristics.In this dissertation,after analyzing and researching the working principle of PLC and the performance test scheme of a special steering gear,an embedded PLC controller with cost-saving,flexible configuration and simple programming is designed for a special steering gear performance testing system.In the hardware aspect,STM32 chip is used as the processor of lower computer.The digital input module and output module which can be operated by the PLC engineer are designed and applied to the switch control of each part of the performance test system.The analog output module for output excitation signal,RS485 communication interface module and CAN bus communication module for downloading program and communication are designed.Based on the development environment of VC++and MFC,the upper computer ladder diagram programming interface is developed,and the compilation process from ladder diagram to executable file is realized.Transplant the real-time operating system of ?C/OS-? into the software system of the lower computer and use a stable download mode of in-application programming to update programs.Through the analysis of the actual test parameters of the steering gear controller obtained from the control of the special steering gear performance test system,the test results of the embedded PLC designed in this dissertation has reached the expectation.