ELEC 242 Lab

Experiment 7.3

Postition Control with Feedback

Part 1: Open Loop Control

Because of the pole at the origin open loop control in the sense of applying a voltage and achieving a corresponding position is not feasible. What we can do is resort to manual control where the user of the system fiddles with the input until the desired result is achieved (or at least approximated).


Step 1:

 Load and start the "Controller 1" program.

Step 2:

 Using the Drive Voltage slider, attempt to achieve positions corresponding to integer values of Vact (the "floors" of our elevator). How close can you get in a reasonable amount of time. Can you go from one floor to another without overshooting?

Part 2: Closed Loop Control

We will look at the closed loop system performance next week. As a preview, let's make sure everything works as it should.


Step 1:

 Now for the moment of truth. Disconnect the motor amplifier input from D/A channel 1 and connect it to the output of the summing amplifier. Connect D/A channel 1 to of the summing amplifier.

Step 2:

 Load the "Controller 2" Labview program. This program generates the appropriate value of to drive to the desired value.

Step 3:

 Turn on the power supply. Start the program and verify that does indeed track the desired value.

Step 4:

 Leave this circuit wired. We will use it again next week.