Effect of delay characteristics of cutting mechanism on forming accuracy of roadway section

Due to the interference of multiple factors,such as the response time difference of actuator,load interference and the compressibility of hydraulic oil,the manual directional valve or electromagnetic direc-tional valve controls the roadheader machine to cut coal and rock with a relatively large delay and low precision of section forming. Considering the influence of the delay of the actuator of the cutting part on the cutting error,the kinematics model of the cutting part is established by d-h method according to the hardware composition and basic parameters of the cutting part. The influence of the motion delay of the cutting mechanism on the cutting control equation is analyzed,and the motion error model of the cutting head center in the coordinate system of the roadway section under the condition of the delay of the cutting action of the transverse pendulum and the longitudinal pendulum is established. The simulation study of cutting control error is carried out using MATLAB numerical calculation software. The results show that under the simulation condition,under the condition of constant transverse velocity,when the delay time is 50,100 and 200 ms,the cutting track error of transverse pendulum cutting is 10,20 and 40 mm,respectively. When the transverse pendulum velocity is 50 mm / s,100 mm / s and 200 mm / s,the cutting track error of the transverse pendulum cutting is 5 mm,10 mm and 20 mm,respectively. With the increase of the transverse velocity and the motion delay of the cutting part,the cutting traj- ectory error increases accordingly. Because the general solenoid directional valve is not easy to control the flow in real time,it is not possible to control the speed of the cutting part. It is necessary to fully understand the delay characteris- tics of the cutting actuator,provide a good lead in the control system,and eliminate the cutting error caused by the ac- tion delay. Through the experimental study using the self-developed experimental platform of driving and supporting anchor,the results show that the actuator of test bench cutting part has a 53 ms delay. Through a leading time control on the control system,namely at the position of 53 ms multiplied by the speed of horizontal pendulum before the cut- ting position displacement sensor reaching the designated displacement,the stop instruction is given,then the cutting error resulted in by action delay can be reduced.