Research On Highly Integrated Valve-controlled Cylinder Position Controll System Parameters Sensitivity Analysis Method

The highly integrated valve-controlled cylinder servo system, which can be a typicalhydraulic driver, can be applied as drivers of military and civilian aircrafts and thehigh-performance two-feet, four-feet and six-feet hydraulic drive bionic robot, having theirreplaceable advantage over the electrical motor and pneumatic driver. To ensure the highperformance of the highly integrated valve-controlled cylinder system, the control methodand the structure parameter optimization design are especially important. And thesensitivity analysis theory can be used to study the influence degree of the varied controland structure parameters on the system dynamic characteristics quantitatively. Throughanalyzing the sensitivity of the highly integrated valve-controlled cylinder, the conclusionis got, which is used for improving the system performance, having the theory researchvalue and application prospects. Further, the applicable sensitivity analysis method of thehighly integrated valve-controlled cylinder system should be pointed out though there aremany sensitivity analysis methods, and the more accurate sensitivity analysis conclusionof each system parameter should be got. This paper sums up the first order trajectorysensitivity analysis, the first order matrix sensitivity analysis and the second ordertrajectory sensitivity analysis, the focus research as following:(1) Build the sixth order nonlinear mathematical model of the highly integratedvalve-controlled cylinder position system, formulate the state space equation, and the firstorder trajectory sensitivity equation group is got as well as the homologous coefficientterms and free matrix. Though the combined solution of the first order linearnon-homogeneous differential equation group and the system simulation model, first ordertrajectory sensitivity functions of seventeen main system parameters under ninedisplacement step response working conditions are calculated, and the homologoussensitivity index value shown with the histogram is analyzed.(2) Build the first order matrix sensitivity equation group of the highly integratedvalve-controlled cylinder position system, and the homologous parameter vectorsensitivity matrix is derived. Through the combined solution of the matrix equation group and the system simulation model, the first order sensitivity matrix and the sensitivity indexvalue of seventeen main system parameters under nine displacement step responseworking conditions are calculated, which is compared with the analysis result of the firstorder trajectory sensitivity.(3) Build the second order trajectory sensitivity general equation group formula andthe special formula adaptive to the parameter sensitivity analysis, and the homologouscoefficient terms and free matrix of the special formula are solved. Through solving thesystem simulation model and the first order linear non-homogeneous parameter-varieddifferential equation group and combining with the calculated first order trajectorysensitivity function, the second order trajectory sensitivity function of seventeen mainsystem parameters under nine displacement step response working conditions arecalculated. Then, the second order trajectory sensitivity of seventeen main systemparameters with different parameters varying scope is analyzed, and with the second ordertrajectory sensitivity index histogram, the comparing analysis with the analysis result ofthe first order trajectory sensitivity and the first order matrix sensitivity is also conducted.(4) Basing on the highly integrated valve-controlled cylinder performance testplatform, with the analogue verification method, through adjusting the controllerproportion gain, the system supply pressure, the servo cylinder initial displacement andthe loading force, the sensitivity index values of the four parameters are tested. Andthrough comparing the analysis results of the three above sensitivity analysis theories, theaccuracy and the applicability of each sensitivity analysis method are analyzed.