Control System Lab Experiment No.-3 VTOL ModellingName- Rahul Kumar Meena(B12089)Group No.-8Group Member- Reeta Meena Seela Aiswarya

Objective- Compute the stiffness (K) in case of VTOL kit. (It can be performedby using current control method explain in manual).

Theory- QNET VTOL is a trainer kit which mimics the parameters considered while vertical take off and take on of Vechical. IN Current control, The VI give open loop voltage to trainer kit. When VI is used incurrent control mode, it regulate the current in the motor with respect to the referencecurrent set by us. When used in voltage mode, the voltage chosen is directly applied to QNET amplifier, which in turn drives the motor.

Fig.-Cascade control system.

A PI current controller, the inner loop, is designed to regulate the current inside the motor according to a desired current reference. This current reference is generated from the outer loop controller: a PID compensator that control that pitch.

In case where the actuator has relatively slow dynamic such as an electromagnet witha large inductance, it is favorable to design a current controller.

In this case, the voltage-current relations of the VTOL trainer motor can be describe, in the time-domain, by the equation Vm(t)=RmPm(t)+LmIm

'(t)

and by the transfer function Im(s)=Vm(s)/(Rm(s)+LmS)

Fig.-Block Diagram

using The PI controller

we obtain the following closed loop transfer function

To match the standard second order characteristic equation, we need a proportional gain

and integral gain

Observation-

To find the resistance we take different voltage and check varied current according to that we are finding the Avg. Resistance.

Voltage Current Resistance

4 1.4 2.857

5 1.7 2.941

6 2.2 2.721

7 2.6 2.692

7.5 2.75 2.727

Current response with no proportional gain Kpc=0 and Kic=100

Current control design-

Equilibrium Current-

Natural frequency-