A PLC-based control system associated with photo-sensors and servo motors to implement the direction-speed control of a guideline-tracing vehicle

• Main Authors: Ya-Jie Yang, 楊雅傑
• Other Authors: Li-John Jou
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/95111252878218935456

碩士 === 國立宜蘭大學 === 生物機電工程學系碩士班 === 98 === The purpose of this thesis was to develop a programmable logical controller (PLC)-based control system associated with four photo-sensors to implement direction-speed control of a tracing guideline vehicle. Two DC and servo motors were respectively employed as moving power to drive a vehicle. By employing a Boolean algebra algorithm, complex logical issues existing in direction-speed control of a tracing-guideline vehicle were deduced to obtain Boolean functions between input and output logical variables of a PLC. The Boolean functions were systematically transformed to PLC group programs that were used as a control core unit to solve the complex logical problems of direction-speed control procedures of a tracing-guideline vehicle. For speed modulation of DC (servo) motors, the technology of pulse width modulation (liner acceleration) was integrated into the control core unit to regulate direction-speed control of a vehicle. By employing the LabVIEW software, a camera was used to capture moving images of a vehicle to construct the image processing technology of analyzing motional characters such as full time, average velocity, tangential velocity and the offset between guideline and the mass center of a vehicle. The developed image measurement system could real-time monitor and analyze the vehicle movement and was designed with some advancing capacities including a configuration-based operation user interface, real-time monitoring displays, on-line data analyses, the function of file access for data storage and automatically report generation. The method of triangle rate revision was used to decrease the image measuring error caused by parallax. The determining normalized root mean squared deviation (NRMSD) of the image measurement system could be reduced to range of 2.713%. The experimental results demonstrated that the vehicle could smoothly move along the preset guideline on the ground in our laboratory.