Study On The Hoisting Performance Of Modern Heavy Hydraulic Mobile Crane

Electric proportional pump-control hydraulic system controlled by PLC and CAN bus is the main format of driving control for modern heavy mobile cranes. When the hydraulic hoisting system is hoisted secondly, it is dynamic performance will directly influence the whole crane function. And making use of PLC and CAN bus control is also good chance for improving the hoisting performance of system. Formerly, traditional pump-valve system is the object of the studies on secondary slide of the hydraulic hoisting mechanism. So it's necessary to have a research on dynamic performance of the pump-control hoisting system. Then we can find a theory support for it which the system not only can prevent slide when it hoists secondly but also have a better quality of transition course and stability by improving the control mode to improve performance of system. It's also an important way to reform the hoisting performance of hydraulic crane.Considering the characters of pump-control system and the control mode which electric-control system can actualize, the dynamic models of the hoisting circuit and the brake circuit are established, and the dynamic performances of the brake, pump-control hydraulic hoisting system while second lifting, and the relationship between load-variable pump-control mode and brake release condition by using the method of digital simulation.(1) By making use of modeling technique of power bond graphics, the mathematics model of the brake release course and the pump-motor system second lifting are established, and then the simulation programs are compiled by Matlab.(2) Models are solved by computer. Dynamic response curves of brake release course and pump-motor system secondary hoist course are obtained separately, then the results of digital simulation is analyzed.(3)Using the simulation results, according to the given system transition quality and stability, the corresponding relationship between controlling method of load-variable pump and brake release condition are gotten, which provides a method and theory gist for improving system secondary hoisting performance by reforming controlling software.