Bolt Wrench And Control System Research And Design

With the development of the speed-increase railways,especially the passenger railways and high-speed railways,stricter criterion of the railway quality is required.Further research has been done on the current status of the tightening bolt,by broadly referring to the tightening technology of the bolt home and abroad,and the tightening automation technology of the bolt in other fields, using the electro-hydraulic proportional control and embedded technology, consulting the idea of intelligent instrument,a new design scheme of bolt wrench is brought up,which can perform the intelligent tightening actions of the two-headed bolt and can concisely adjust the tightening torque and show the torque and status and so on.The efficiency of the maintenance of the railways can be greatly raised,the labor strength can be reduced,the connecting quality between the rail fastening and linking nut of the rail can be increased to meet the demands of the development of the high-speed railways by the success of the hydraulic bolt wrench.In the measurement and control system of the bolt wrench,the electro-hydraulic proportional valve-controlled motor technology is used.The torque can be acquired by measuring directly and can be controlled by the closed-loop of negative feedback.The 16-bit MCU MSP430F1611 is used as the core of the hardware system and the software framework is based on theμC/OS-Ⅱreal-time operating system,which uses the digital PID algorithm to realize the precise control of the torque.The main content of the thesis is as follows:Firstly,the research background of the bolt wrench is introduced.The actuality and development of sleeper-used bolt wrench are introduced,according to which,the existing problems of the current hydraulic torque are pointed out and then the direction of the research is decided.At the same time,the technology of embedded system and intelligent instrument are studied detailedly.After these, the content,purpose and main work of the thesis are confirmed.Secondly,the overall design and modeling analysis are done for the measurement and control system.By analyzing the purpose of the design of the bolt wrench,the overall system is designed and the structure and principle of the bolt wrench are elaborated.According to the analysis of requirements,the electro-hydraulic proportional valve-controlled motor torque control system is designed,the appropriate torque sensor is selected,mathematical model is built for analyzing the principle and each part of the control system,and the digital PID control is selected.Then,the overall scheme of the hardware and software is analyzed and designed,and by analyzing the current status of the embedded system,theμC/OS-Ⅱembedded real-time operating system is chosen and the selection of the circuit of the hardware is designed.Thirdly,the hardware and software of the bolt wrench are studied and designed.Through comprehensive consideration of the demands,the economy, the reliability,the convenience of the interface,the specified electronic components for the system of the measurement and control are selected and all function circuits of the system are designed,including the CPU function circuits,the sensor circuits,the signal conditioning circuits,the data acquisition circuits,the electro-hydraulic proportional valve drive circuits,switching solenoid valve drive circuits,the human-computer interface circuits,the power circuits,auxiliary debugging circuits and so on.During this process,the precision of the data acquisition is demonstrated and the anti-interference of the system is analyzed and designed.By designing the software of the system of the measurement and control,the development environment of the MSP430 software is introduced and the overall structure of the software of the system of the measurement and control is shown.Then theμC/OS-Ⅱembedded real-time operating system is transplanted on the MSP430F1611 and the software of the system of the measurement and control is designed by layers and by studying the algorithm of the torque control,the parameters of digital PID controller is designed.Finally,a sample-machine is developed for field tests.The tests show that all the functions of the system are satisfied with the design requirements.The results of field tests show that the bolt wrench is precise,credible,well repeated, fast measured.