Engineering

7ENGINEERING

Engineering

Engineering

Introduction

Balancing is important in most control activities. In this experiment, we develop oversight mechanisms that ideally balance the pendulum in a vertical position whereas retaining the preferred location of the arm. An energy founded control is formulated by the QNET rotary pendulum swing up control VI, it turns to a vertical position, at the same time, a state-feedback controller that balances the pendulum when it is located in an upright position. It is important to note that while adjusting and regulating the swing over a developed point the arm often sways about the reference due to the grinding that exists in the motor.

Consequently, as a result of rubbing the motor does not change its position while waiting for the control sign to be sufficiently broad and the formed torque greater than the friction. Therefore, the pendulum needs to fall to a particular point before the motor moves making the outcome is a wavering movement. Friction can be waged through putting a Dither sign at the data voltage of the DC motor. The used Dither signal may have the following structure:

V_d=A_d Sin f_d t+V_d0

Where A_dis the voltage amplitude, f_dis the sinusoid frequency, and finally, V_d0is the offset voltage of the signal.

The purpose of this work is to look at how contact actuated motions occur as a result of high recurrence excitations, commonly known as Dither signals.

The simulation loop as employed in the exercise is used to analyze the output; it affects the reenactment graph until the control as well as the simulation loop realizes the redevelopment the last time. Also, the Halt simulation capacity can stop the activation routinely. The recreation subsystems are supposed to be placed in a control and simulation loop or a square outline outside the former. Moreover, the subsystems can still be contained in other reenactment subsystems or better still the process can be run with subsystems as stand-alone Vis.

Engineering

Schematics & Procedure

  1. Open the QNET_ROTPENT_Swing_Up_Control.vi (Make sure the correct Device is chosen.)

  2. Run the QNET_ROTPENT_Swing_Up_Control.vi.

  3. In the Signal Generator section set:

  • Amplitude = 0.0 deg

  • Frequency = 0.10 Hz

  • Offset = 0.0 deg

  1. In the Balance Control Parameters section set:

  • kp_theta = -6.5 V/rad

  • kp_alpha = 80 V/rad

  • kd_theta = -2.75 V/(rad/s)

  • kd_alpha = 10.5 V/(rad/s)

  1. In the Swing-Up Control Parameters section set:

  • mu = 55 m/s2/J

  • Er = 20.0 mJ

  • max accel = 10 m/s2

  • Activate Swing-Up = OFF (de-pressed)

  1. Adjust the Angle/Energy (deg/mJ) scope scales to see between -250 and 250.

  2. Manually rotate the pendulum in the upright position until the In Rang. LED in the Control Indicators section turns bright green at this point.

  3. Vary Offset and observe the Arm Angle (deg) response in the Angle/Energy (deg/mJ) scope.

  4. As the pendulum is being balanced, describe the red Arm Angle (deg) and the blue Pendulum Angle (deg) responses in the Angle/Energy (deg/mJ) scope.

  5. In the Signal Generator section set:

  • Amplitude = 45.0 deg

  • Frequency = 0.10 Hz

  • Offset = 0.0 deg

  1. Click on the Stop button to stop running the VI.

Designed balance controller parameters:

  • Amplitude = 45.0 deg

  • Frequency = 0.20 Hz

  • Offset = 0.0 deg

Balance Control with Friction Compensation parameters:

  1. Signal generator

  • Amplitude = 0.0 deg

  • Frequency = 0.10 Hz

  • Offset = 0.0 deg

  1. Dither Signal

  • Amplitude = 0.00 V

  • Frequency = 2.5 Hz

  • Offset = 0.00 V

Results and Discussions

The typical procedure was followed, and various challenges were faced while carrying out the experiment, such as in the seventh step, we had to make sure that the encoder cable did not impede with the pendulum arm while in motion during every test. In the subsequent step, we were not able to set the offset too high because the encoder cable could have interrupted the pendulum arm that was in motion.

We responded to the number of issues that came up during the performance of the experiment. At step 8 by varying the offset, it came to our attention that by increasing the offset, the arm angle is also increased, and if the opposite is repeated the same outcome is noticed.

At the ninth step, it is evident that the Red Arm Angle and the blue pendulum angle stabilizes the arm angle for ideal balancing. When a square wave is exerted on the arm angle, the arm moves in the unintended direction due to the overshadowed inertia of the body and to even out the arm angle.

Engineering 1

Engineering 2

Conclusion

Conclusively, it was agreed that by employing the accurate parameters as well as adjusting the offset will lead to the pendulum to balance in an upright position. Moreover, setting up the controls of friction using the dither signal demonstrated that the dither is meant for doing away with friction and can at times destabilize the signal.