IntroductionBackground ReadingPre-Lab Experiment 1: Run a VI for Computing Frequency Response Specify Sampling ParametersRun Your VIExperiment 2: Obtain the Frequency Response of an Analog Low-Pass FilterAdd Smoothing WindowExperiment 3: Obtain the Frequency Response of an Analog High-Pass FilterExperiment 4: Obtain the Frequency Response of an Analog Band-Pass FilterExperiment 5: Obtain the Frequency Response of a DC MotorSet Up DC Motor Control ModuleObtain Frequency Response of DC MotorExperiment 6: Obtain the Frequency Response of a DC Motor under an Applied LoadExperiment 7. Verify Amplitude of Frequency ResponseSet Up Function GeneratorSet Up DC Motor Control ModuleRecord Amplitude of Frequency Response Saving FilesLaboratory Report Additional Reading and PracticeME 104 Sensors and Actuators Laboratory 5 Frequency Response Department of Mechanical Engineering University of California, Santa Barbara (Rev. 2007)Introduction In this laboratory, you will use a LabVIEW VI that will enable you to obtain the frequency response (magnitude and phase) of an external system. You will use this VI to obtain (separately) the frequency response of an analog low-pass filter, an analog high-pass filter, an analog band-pass filter, and a DC motor. Background Reading Please read the following material prior to this lab: 1. Histand and Alciatore, Introduction to Mechatronics, Sections 4.4-4.5 and Section 4.10.2 (Up to and including Equation 4.73). 2. DC Motor Control Module User Manual, Pages 3-7 and 14-16, LJ Technical Systems Inc. Pre-Lab 1. Given 10-kΩ resistors and 0.1-μF capacitors, determine how to build a. an RC low-pass filter with a cut-off frequency of 1000 rad/s (159 Hz) b. an RC high-pass filter with a cut-off frequency of 1000 rad/s (159 Hz) c. an RC bandpass filter with a pass-band of 159 to 339 Hz. 2. Please review the VI, lab5_ex1.vi, for this lab to ensure your understanding of them prior to this lab. The share drive for this course is accessible from the computers in the CAD lab and Rm. 2218. For Lab 5, go to My Computer >> Network Drives >> melab >> ME 104 >> Lab 5. Figure 1. Block diagram of VI for Lab 5, lab5_ex1.vi 2Experiment 1: Run a VI for Computing Frequency Response In this experiment, you will use a LabVIEW VI to compute the frequency response of an external system. DAQ board PC D/A Converter A/D Converter External System Figure 2. Measuring the frequency response of an external system Specify Sampling Parameters 3. Open lab5_ex1.vi provided for Experiment 1. Go to My Computer >> Network Drives >> melab >> ME 104 >> Lab 5. 4. Go to the front panel. Enter the values for the sampling parameters as indicated in Table 1. Table 1. Sampling Parameters for Lab 5 VI Parameter Value # Samples 2048 Sampling Frequency 1000 Averages 20 This specifies that you will generate and collect 2048 samples at a rate of 1000 samples per second (1 kS/s) and you will do this 20 times. Most digital signal processing algorithms (such as computation of frequency response) work fastest when the number of samples is a power of 2. Run Your VI 5. Run your VI by clicking the Run button. The VI will run for just over 40 seconds before the frequency response is displayed. 6. Save this VI as yourname_lab5_ex1.vi. 3Figure 3. Display on yourname_lab5_ex1.vi after running it without any connections to the connector block. Your frequency response indicates that there is no system!1 This should come as no surprise since you have not connected anything to your connector block. Notice that the maximum frequency displayed on your frequency response plots is 500 Hz, which is ½ of the sampling frequency of 1000 Hz. Experiment 2: Obtain the Frequency Response of an Analog Low-Pass Filter In this experiment, you will use a modified version of the VI from Experiment 1 to obtain the frequency response of an analog low-pass filter. 1 Actually, a “system” does exist (the air in the laboratory), but this is of little practical interest. 4DAQ board D/A Converter A/D Converter Low-Pass Filter PC Figure 4. Obtaining the frequency response of an analog low-pass filter 1. Build the RC low-pass filter shown in Figure 5. Choose the resistor RLP and the capacitor CLP such that RLP = 10 kΩ and CLP = 0.1 μF. VINVOUT Figure 5. RC Low-pass filter. Then, the cutoff frequency ω0 of the filter is given by rad/s 100010==RCω or Hz. 159200==πωf 2. Provide ground (GND) to your circuit board using the black (-) terminal of the “5 V FIXED 3 A” output from your Tektronix PS280 DC Power Supply. You do not need to turn on the power supply. 3. Connect your circuit to the connector block such that the voltage input to your low-pass filter is provided from Analog Output Channel 0 (AO0). Remember to provide Analog Output Ground (AOGND) to the connector block as in previous laboratories. Refer to the pin-out diagram for the connector block. 4. Connect your circuit to the connector block such that the voltage output from your low-pass filter is sent to Analog Input Channel 0 (AI0). Remember to provide 5Analog Input Ground (AIGND) to the CONNECTOR BLOCK as in previous Laboratories. 5. Open and run yourname_lab5_ex1.vi. The VI will run for just over 40 seconds before the frequency response is displayed. 6. Your axes should be linear. Obtain a printout of your front panel for your Lab Report. 7. Format the x-scale of both of your Frequency Response graphs such that the frequency axes are displayed on a fine logarithmic scale2. (The y-axes should remain linear.) You may have to change your axes colors for better viewing. Remember to obtain a printout of your front panel (frequency response) for your Lab Report. Figure 6. Frequency response of an analog low pass filter. Add Smoothing Window The frequency response of your low-pass filter appears distorted due to a phenomenon known as spectral leakage. To reduce the effects of spectral leakage, add a smoothing window3 to your time-domain signal. 8. Add two Hanning Windows to the block diagram of yourname_lab5_ex1.vi as shown in Figure 7. Hanning Windows are useful for general-purpose windowing applications. 9. Save this as yourname_lab5_ex2.vi. 10. Run your VI by clicking the Run button. The VI will run for just over 40 seconds before the frequency response is displayed. 2 For instructions, refer to Lab 3, Experiment 5. 3 See Additional Reading section to