Abstract:
An important target of intelligent working face construction in coal mines is that the hydraulic supports can follow the shearer at intelligence and automatization level. Aiming at the problems above,the hydraulic supports’ ac- tion execution speed and accuracy are insufficient due to unfitted fluid feeding during moving with the shearer. With the target of the hydraulic power adapting to the hydraulic supports moving after the shearer closely and steadily,an adaptive control method for fluid feeding with steady pressure that cooperating with hydraulic support control strategy is proposed. Based on the principle of fluid feeding with steady pressure which the fluid feeding flow should be pre a- dapted properly according to the action characteristics of hydraulic supports,combining the characteristics of multipump and variable frequency fluid feeding,a synergetic control logic of overlapping fluid feeding and hydraulic support is proposed. According to the principle of hydraulic transmission,the solution equations of hydraulic supports following the velocity and pressure change rate of hydraulic system under the above logic are deduced,which reveals the cou- pling mechanism between the control strategy of fluid feeding flow and the action strategy of hydraulic supports. Based on the multi-response optimization problem solving theory,making the proper moving speed of the hydraulic support following the shearer and the stable pressure of its each action as multiple objectives,the satisfaction function of the hydraulic support moving effect is constructed and solved by the bi-level programming method. Then,the intelligent de- cision-making of self-adaptive control strategy of fluid feeding for the hydraulic supports moving is presented. By the joint simulation of MATLAB and AMESim,the different control methods of hydraulic supply such as the multi-pump joint control,the frequency conversion constant pressure and the self-adaptive fluid feeding with steady pressure are simulated in the same operation process of hydraulic support. The pressure mean,the pressure variance,the number of times of unloading,the average relative error of operational stroke of hydraulic support and the efficiency of fluid feed- ing for these three methods are compared comprehensively,which have verified the advantages of the proposed meth- ods. Finally,the method is validated by industrial tests. The conclusion is that the self-adaptive control method of fluid feeding with steady pressure has better steady pressure effect,which shows it has higher feasibility.