Nowadays, a highly integrated valve?controlled cylinder(HIVC) is applied to drive the joints of legged robots. Although the adoption of HIVC has resulted in high?performance robot control, the hydraulic force system s...Nowadays, a highly integrated valve?controlled cylinder(HIVC) is applied to drive the joints of legged robots. Although the adoption of HIVC has resulted in high?performance robot control, the hydraulic force system still has problems, such as strong nonlinearity, and time?varying parameters. This makes HIVC force control very diffcult and complex. How to improve the control performance of the HIVC force control system and find the influence rule of the system parameters on the control performance is very significant. Firstly, the mathematical model of HIVC force control system is established. Then the mathematical expression for parameter sensitivity matrix is obtained by applying matrix sensitivity analysis(PSM). Then, aimed at the sinusoidal response under(three factors and three levels) working conditions, the simulation and the experiment are conducted. While the error between the simulation and experiment can’t be avoided. Therefore, combined with the range analysis, the error in the two performance indexes of sinusoidal response under the whole working condition is analyzed. Besides, the sensitivity variation pattern for each system parameter under the whole working condition is figured out. Then the two sensitivity indexes for the three system parameters, which are supply pressure, proportional gain and initial displacement of piston, are proved experimentally. The proposed method significantly reveals the sensitivity characteristics of HIVC force control system, which can make the contribution to improve the control performance.展开更多
An experimental study on flowrate and stability of a type of control valve of 600MW supercritical steam-turbine was presented by measuring instruments of static, dynamic pressure and vibration in self-designed test ri...An experimental study on flowrate and stability of a type of control valve of 600MW supercritical steam-turbine was presented by measuring instruments of static, dynamic pressure and vibration in self-designed test rig. The investigation shows that flow coefficient is 30% up more than that of the control valve of GX-1 type used widely in domestic power plants now, as small-medium lifts. If the relative lift (h/D) is less than 20%, the valve can always work steadily in all the pressure ratios. When the h/D is between 20% to 24%, big vibration of valve stem occurs if the pressure ratio is between 0.7 to 0.8. When h/D is more than 25%, relatively great vibration happens in a wide range of pressure ratios of 0.4 to 0.85.展开更多
This paper discusses causes of the rate ripple in inertia guidance test equipment IGET,systematically analyses their effects on the rate ripple in IGTE.The analysis result shows:The rate ripple caused by the periodic ...This paper discusses causes of the rate ripple in inertia guidance test equipment IGET,systematically analyses their effects on the rate ripple in IGTE.The analysis result shows:The rate ripple caused by the periodic errors of inductosyn and angular encoder is higher at high speed than that caused by magnetic ripple torque and friction torque,and it cannot be eliminated by adjusting control parameters of the system.And based on the nonlinear adaptive control system theory,the paper puts forward a new control system scheme to eliminate the rate ripple caused by the periodic errors of inductosyn and angular encoder,develops the adaptive control rules and makes simulation and test.Experimental result shows a significant improvement on those tables for the period disturbs under the system scheme designed.By this plan,with the input of rate 200°/s,the rate ripple falls from 5°/s to 0.4°/s within about 6s adaptive adjustment time,being a twelfth of before adaptation,which can not be reached by common classical controls.The experimental results conform with the simulation,which proves the validity and practicability of the plan.展开更多
基金Supported by National Natural Science Foundation of China(Grant No.51605417)Key Project of Hebei Provincial Natural Science Foundation,China(Grant No.E2016203264)State Key Laboratory of Fluid Power and Mechatronic Systems(Zhejiang University)Open Fund Project(Grant No.GZKF-201502)
文摘Nowadays, a highly integrated valve?controlled cylinder(HIVC) is applied to drive the joints of legged robots. Although the adoption of HIVC has resulted in high?performance robot control, the hydraulic force system still has problems, such as strong nonlinearity, and time?varying parameters. This makes HIVC force control very diffcult and complex. How to improve the control performance of the HIVC force control system and find the influence rule of the system parameters on the control performance is very significant. Firstly, the mathematical model of HIVC force control system is established. Then the mathematical expression for parameter sensitivity matrix is obtained by applying matrix sensitivity analysis(PSM). Then, aimed at the sinusoidal response under(three factors and three levels) working conditions, the simulation and the experiment are conducted. While the error between the simulation and experiment can’t be avoided. Therefore, combined with the range analysis, the error in the two performance indexes of sinusoidal response under the whole working condition is analyzed. Besides, the sensitivity variation pattern for each system parameter under the whole working condition is figured out. Then the two sensitivity indexes for the three system parameters, which are supply pressure, proportional gain and initial displacement of piston, are proved experimentally. The proposed method significantly reveals the sensitivity characteristics of HIVC force control system, which can make the contribution to improve the control performance.
基金This work was supported by National Natural Science Foundations of China (No503360501,50323001)
文摘An experimental study on flowrate and stability of a type of control valve of 600MW supercritical steam-turbine was presented by measuring instruments of static, dynamic pressure and vibration in self-designed test rig. The investigation shows that flow coefficient is 30% up more than that of the control valve of GX-1 type used widely in domestic power plants now, as small-medium lifts. If the relative lift (h/D) is less than 20%, the valve can always work steadily in all the pressure ratios. When the h/D is between 20% to 24%, big vibration of valve stem occurs if the pressure ratio is between 0.7 to 0.8. When h/D is more than 25%, relatively great vibration happens in a wide range of pressure ratios of 0.4 to 0.85.
文摘This paper discusses causes of the rate ripple in inertia guidance test equipment IGET,systematically analyses their effects on the rate ripple in IGTE.The analysis result shows:The rate ripple caused by the periodic errors of inductosyn and angular encoder is higher at high speed than that caused by magnetic ripple torque and friction torque,and it cannot be eliminated by adjusting control parameters of the system.And based on the nonlinear adaptive control system theory,the paper puts forward a new control system scheme to eliminate the rate ripple caused by the periodic errors of inductosyn and angular encoder,develops the adaptive control rules and makes simulation and test.Experimental result shows a significant improvement on those tables for the period disturbs under the system scheme designed.By this plan,with the input of rate 200°/s,the rate ripple falls from 5°/s to 0.4°/s within about 6s adaptive adjustment time,being a twelfth of before adaptation,which can not be reached by common classical controls.The experimental results conform with the simulation,which proves the validity and practicability of the plan.
