Design Of Automatic Control System For Non-destructive Testing Of Train Wheels

Locomotives cannot run at high speed without the support of high quality wheels.As one of the important components of locomotives,wheels are the key to ensure safe and efficient operation of locomotives.The rims of locomotive wheels are subject to residues(porosity,inclusions)in the process of casting and processing in the locomotive factory.Therefore,before the wheels are put into use,the rims and other parts need to be inspected by flaw detection execution equipment to ensure that the wheels are in a healthy state,thus ensuring safe and efficient operation of the locomotive.In this paper,the main research content is the action process of wheel tread and rim flaw detection,and we designed the control system of flaw detection execution action process of wheel tread and rim inspection execution equipment is designed to realize the purpose of automatic inspection with high accuracy and efficiency of inspection execution equipment according to the set motion trajectory.(1)The control function of wheel flaw detection control system can be clarified by analyzing the process flow of flaw detection.Based on this,the selection of hardware such as PLC,servo driver,servo motor and hydraulic solenoid valve is completed,and the overall scheme of the flaw detection control system is designed by combining the selected hardware and the control requirements.(2)A non-destructive wheel flaw detection control system with Siemens S7-1214 C PLC as the controller and Lab VIEW development environment as the upper computer operator interface was designed.Action control system is designed through using PLC for coupling liquid tank injection and discharge,pushing probes,probe detection and so on.Upper computer is used to design the login interface,main interface and servo parameter configuration interface of the control system.(3)Based on PROFINET communication protocol,the S7-1214 PLC realizes the EPOS basic positioning control mode of V90 servo drive,the drive drives the wheel rotation by sending pulse to the motor with the reducer,and the rotation angle and angular velocity are used as the moving displacement and velocity enabling values of the rim flaw detection probe,and the PLC completes the sampling of the analog quantity of the enabling value and sends the analog quantity to the motor to drive the probe in the rim flaw detection.The encoder feeds back the moving displacement and speed of the probe to the PLC,and the PLC transmits the feedback information to the upper computer through TCP communication,realizing the data interaction between the upper PC and the lower PLC.(4)The incremental PID algorithm is applied to the closed-loop control of the position and speed of the servo motor,and use the human-machine interface to observe the real-time dynamic response curve of the servo motor’s rotation and speed during the control process.Combined with the PLC and servo motor PID parameter adjustment function test,through the observation of the upper computer interface PID position loop and speed loop parameter adjustment curve can know that the control system designed in this paper has relatively higher precision and stability,which is able to meet the high precision control requirement of field rim probe flaw detection,and posses strong practicality as well.