Table 2 Simulation model parameters and initial values of pump–valve composite driving force control system
Parameter | Initialization value | Unit | Parameter | Initialization value | Unit |
|---|---|---|---|---|---|
Voltage and current conversion coefficient of motor \(K_{V}\) | 7.5 | A/V | Current feedback coefficient \(K_{f}\) | 1 | – |
Motor armature inductance \(L\) | 3.28 × 10−4 | H | Motor armature winding resistance \(R\) | 5.74 × 10−2 | Ω |
Electromagnetic torque system of motor \(K_{c}\) | 31.28 | V/(rad/s) | Motor torque coefficient \(K_{t}\) | 1.75 | N·m/A |
Inertia of servo motor shaft \(J_{T}\) | 4.55 × 10−3 | (kg·m2) | Viscous friction coefficient of servo motor \(B_{T}\) | 0 | N·m (rad/s) |
Displacement of gear pump | 1.05 × 10−6 | m3/rad | Internal leakage coefficient of gear pump \(K_{ip}\) | 1 × 10−12 | m3/(s·Pa) |
External leakage coefficient of gear pump \(K_{ep}\) | 0 | m3/(s·Pa) | Asymmetric cylinder piston rodless cavity area \(A_{{{\kern 1pt} 1}}\) | 6.62 × 10−4 | m2 |
Rod cavity area of asymmetric cylinder piston \(A_{{{\kern 1pt} 2}}\) | 6.62 × 10−4 | m2 | Asymmetric leakage coefficient outside cylinder \(C_{{{\kern 1pt} em}}\) | 0 | m3/(s·Pa) |
Asymmetric in-cylinder leakage coefficient \(C_{{{\kern 1pt} im}}\) | 0 | m3/(s·Pa) | Total equivalent mass on asymmetric cylinder piston \(m_{{{\kern 1pt} t}}\) | 3.2 | kg |
Load stiffness of asymmetric cylinder \(K\) | 5 × 105 | N/m | Damping coefficient of asymmetric cylinder piston and load \(B_{{{\kern 1pt} p}}\) | 0 | N/(m/s) |
Coulomb friction force of asymmetric cylinder \(F_{{{\kern 1pt} f}}\) | 0 | N | Load force exerting on asymmetric cylinder piston \(F_{{{\kern 1pt} L}}\) | 0 | N |
Connection volume between rodless cavity and gear pump \(V_{{{\kern 1pt} g1}}\) | 3.93 × 10−5 | m3 | Connecting volume of rod cavity and gear pump \(V_{{{\kern 1pt} g1}}\) | 3.93 × 10−5 | m3 |
Operating chamber volume of gear pump \(V_{{{\kern 1pt} p1}}\) | 3.34 × 10−6 | m3 | Operating chamber volume of gear pump \(V_{{{\kern 1pt} p2}}\) | 3.34 × 10−6 | m3 |
Total stroke of asymmetric cylinder \(L\) | 0.075 | m | Initial position of asymmetric cylinder \(L_{0}\) | 0.035 | m |
Flow pressure coefficient of unidirectional valve | m3/(s·Pa) | Initial pressure of booster tank \(P_{{{\kern 1pt} gp}}\) | 0.5 | Pa | |
Initial volume of pressurized tank gas \(V_{{{\kern 1pt} gv}}\) | m3 | Effective bulk elastic modulus of aviation hydraulic oil \(\beta_{{{\kern 1pt} e}}\) | 8 × 108 | Pa | |
Gain of pressure sensor | 5 | V/bar | Aviation hydraulic oil density \(\rho\) | 0.867 × 103 | kg/m3 |
Servo valve current gain \(K_{xv}\) | 0.05 | m/A | Servo valve power amplifier gain \(K_{{{\kern 1pt} a}}\) | 0.009 | A/V |
Damping ratio of servo valve \(\xi_{{{\kern 1pt} sv}}\) | 0.67 | – | Natural frequency of servo valve \(\omega_{{{\kern 1pt} sv}}\) | 502.4 | rad/s |