.Servomechanisms.Examples.RRServomechanism.RRMotor2

Information

General

With this example the user can characterize the motor for a selected joint by its transfer function assuming a first order transfer function. With the transfer function obtained a proportional gain is then calculated for a proportional control.

Implementation

The system is interconnected using the SignalDCMotor for one joint and a Position source for the other joint (to maintain it at its initial position).
Once simulated, the values of tau (time constant T) and K (gain k) are obtain for the equivalent first order transfer function with the relations:

K = gain of system for steady state/ reference value
tau = time to reach ~ 0.63K

Then the proportional gain is calculated for a maximum overshot (O) requirement using the following equation:

Note that O is the overshot value (for example 0.1) not a porcentual overshoot PO (for example 10%).

Notes

The PID block controller type must be .Modelica.Blocks.Types.SimpleController.P for proportional control.
At the moment the K and tau values are obtain after simulating and observing speed responce of motor.
At the moment the kp value should be calculated externally, although it could be implemented using a modelica function

Example

Results:

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