Download ME417 Lab 3: Control Systems Experiment and Data Analysis - Prof. David Alciatore and more Lab Reports Control Systems in PDF only on Docsity! ME417 Lab 3 1 Objectives The primary objectives of this lab are: • Familiarize student with the general setup of the ECP lab stations (this will save time in the future). • Familiarize the student with the correlating real world data with modeling and simulation. 2 Getting Familiar with the General Setup of the ECP lab Station. 2.1 Safety Familiarize yourself with section 2.3 Safety in the blue user’s manual (pages 34-36). 2.2 The Setup for the Model 220 Servo Trainer Lab Station (Motor Gear Drive System) Start the ECP program by finding the ECP32 icon on the Start/Programs menu on Win NT/Desktop. Turn on power to the ECP lab station. Under Setup, select the User Units to be counts Use the Setup menu to locate and select Algorithm. When Algorithm is selected, select the following Set control Algorithm to: Type=Continuous Time Control Algorithm=PID Click on Setup Algorithm and set the constants Kp=0.05 Kd=0.0, Ki=0.0. Select feedback to be from Encoder 1 and click OK Select Implement Algorithm. This will load the algorithm into the ECP work station. Click OK to close window Select Trajectory from the Command menu. Select a Step input as the reference input to the system. Setup the Step Size to 4000 counts with a Dwell time of 1000 msec. Number of repetitions is 1. It will be a closed loop step. Click OK to close the window. Click OK to exit Trajectory settings. 1 of 4 ME417 Lab 3 2.3 Setting up the Plot Select Data and Setup Data Acquisition from the menu. Use the Add Item buttons to add items to the plot. Choose the Commanded Position, and Encoder Position 1. Set the sample period to 2 Servo cycles. Click OK Under Plotting, select Setup Plot. Using the Add to Left Axis button, select the Commanded Position and the Encoder 1 Position. Click OK. Use Axis Scaling to zoom in and out on given portions of the plot for more accurate data recording. 2.4 Initializing the Lab Station Under Utility, select Zero Position. 2.5 Running the Control Choose Command, Execute (select Normal Data Sampling, if not checked), Run. Plot the data using the Plotting menu. Include this plot with your report. Measure the height of the first overshoot compared to the requested step. Calculate Percentage overshoot __________%. Measure the time duration between successive overshoots and record, convert this value to frequency also: Time between successive overshoots_______ seconds, equates to a frequency of _________Hz. 2.6 Frequency Sweep Set the PID parameters for Kp=1, Kd=.005. Set the trajectory for a sine sweep between 5 and 20 Hz, over a 30 second timespan, with an amplitude of 50 counts. This should be a closed loop linear sweep. Plot the encoder 1data with time along the horizontal axis and amplitude along the vertical axis. Does what you’re seeing make any sense to you? Now replot the data with frequency along the horizontal axis and amplitude along the vertical axis. Does this make more sense? OK, now plot the magnitude in dB along the vertical axis and frequency along the x-axis (include this plot only). Explain what you’re seeing in terms of the system. 2.7 Adjusting Parameters Use a step trajectory as originally setup, but with a dwell time of 2000 msec. Make the PID parameters Kp=.2 and Kd=.005. Run the step response and examine a plot of the commanded position and the encoder 1 output. Now adjust Ki to .5 and re-run the step (don’t forget to re-implement the algorithm). Examine a plot of the commanded position and the encoder 1 output. 2 of 4
