Hydraulic Actuator with Analog Position Controller and Dashboard Blocks
Warning: This example uses the hydraulic domain, which will be removed in a future release. Find an equivalent example model that uses the isothermal liquid domain here: Hydraulic Actuator with Analog Position Controller and Dashboard Blocks. To convert models to the isothermal liquid domain, use the hydraulicToIsothermalLiquid tool.
This example shows how to model a system that spans the electrical, mechanical, and hydraulic domains by using the Foundation block library.
In the model, a hydraulic system controls mechanical load position in response to a voltage reference demand. If the reference demand is zero, then the hydraulic actuator and load displacement is zero. If the reference is +5 volts, then the displacement is 100 mm.
The proportional plus integral controller uses op-amps, the final stage of which is a current source. The current source drives a torque motor with resistance and inductance terms. The torque motor directly actuates the spool valve, which controls the main hydraulic circuit supplying the hydraulic ram. Finally, the ram drives a generic mechanical load.
A model with this level of fidelity can support design and testing of the servo-valve controller. It includes the electromechanical high frequency modes that affect stability margins, as well as nonlinear flow rate effects when large demands are made from the hydraulics.
This example includes animations of the actuator and pressure gauges created using a Vertical Gauge block and two Circular Gauge blocks from the Simulink / Dashboard / Customizable Blocks library.
Model
Actuator Control Circuit Subsystem
Spool Valve Subsystem
Motor Control Circuit Subsystem
Simulation Results from Scopes
Simulation Results from Simscape Logging
The figure below shows the cylinder pressures and load position plotted in a MATLAB figure. You can also view this data in the Simulation Data Inspector by clicking the View cylinder pressures hyperlink in the model canvas or by clicking the Data Inspector button on the model Simulation tab.
