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Notation | Description | Unit |
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A | Pressurized area of hydraulic cylinder of EHA | m2 |
| Viscous friction coefficient | N/m/sec |
| Equivalent leakage coefficient | m3/sec/Pa |
| Pump displacement | m3/rad |
| Position error | mm |
| Current | Arms |
| Pipe coefficient relating pressure drop to flow | Pa/m6/sec2 |
| Angular velocity to voltage gain |
— |
| Proportional control gain | — |
| Integral control gain | — |
| Differential control gain | — |
| Antiwindup gain | — |
, , ,, , | Positive design parameters of adaptive PID sliding mode controller | — |
, , , | Parameters of dynamic model for the BLDC motor with controller | — |
L | Internal leakage coefficient of the cylinder | m3/Pa/sec |
M | Mass load of position control test rig of EHA | N |
, | Cylinder inlet/outlet chamber pressure | Pa |
| Pressure drop of pipe between the pump and the cylinder | Pa |
, | Cylinder inlet/outlet flow | m3/sec |
| Laplace operator | — |
| Torque of BLDC motor | Nm/(rad/sec) |
| Sampling time | sec |
, | Volumes of inlet/outlet pipe and cylinder chamber | m3 |
| Mean volume of pipe and cylinder chamber. | m3 |
| Voltage signal of error for angular velocity of BLDC motor | V |
| Voltage signal of reference angular velocity of BLDC motor | V |
| Voltage signal of angular velocity | V |
| Cylinder displacement | m |
| Desired step response of the optimal PID and antiwindup PID control system | — |
| Step response by the identified transfer function | — |
| Effective bulk modulus | Pa |
| Pump angular velocity | rad/sec |
| Sliding surface | — |
| Pump cross port leakage coefficient | m3/Pa/sec |
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