Plc Control Technology Applied Research In The Intelligent Control Of The Grab Crane

This paper mainly studied the way of carne with grab adopting advanced PLC, frequency converter and absolute encoder to take place traditional electrical control methods so as to upgrade the efficiency of crane with grab, decrease the fault rate and lessen the maintenance costs, the maintenance workload greatly reduced operations become a simple, semi-automatic operation can be realized to reduce man-made accidents operation, running reliable, and saving energyThis paper emphatically studied the principle of the automatic opening and closing action of grab bucket,and pointed out the principle and physical meanings of the coordinate method with a moving reference point, how to use absolute encoder to detect the hoisting,closing grab bucket and measure the length of hoisting cable, which has great practical application value. And develop Fault indication according to some normal faults of crane with grabThe paper consists of four parts:The first part (chapter 1) mainly introducted the working principle of crane with grab, the problem of traditional control methods as well as the possibility and meaning of realizing intelligent operating of crane with grab.The second part (chapter 2, chapter 3 and chapter 4) talked about the form, function and principle of PLC, frequency converter and absolute encoder. This part will lay a theoretical foundation for the realizing of intelligent control of crane with grab in the following part.The third part (chapter 5) research the implementation scheme of accomplishing intelligent control of crane with grab and the principle connection and working principle crane mechanism ,crab mechanism, hoisting mechanism and closing mechanism of PLC, frequency converter as well as absolute encoder, especially the principle of automatic opening and closing actions of grab bucket the accomplishing of automatic grabbing. This part also introduced the principle of using encoder instead of hoisting limiter .The fourth part (chapter6) attaches great importance on introducing the structure of intelligent control software PLC configuration as well as detailed write the software program of crane mechanism ,crab mechanism, hoisting mechanism closing mechanism and fault indication.Finally, a summary for the entire study, and the future research directions are discussed.