Active vibration control is defined as a technique in which the vibration of a structure is reduced or controlled by applying counter force to the structure that is approximately out of phase but equal in amplitude to the original vibration. Techniques like the use of spring, dampers and pads are known as passive vibrations controlled.
A PID controller is a control loop feedback mechanism (controller) extensively used in control systems. What it does?? It calculates an "error" value as the difference between a measured process variable and a desired set point which is given as input initially. It attempts to minimize the error by adjusting the process control inputs.
Proportional it depends on the present error Integral it depends on the accumulation of past errors Derivative it is a prediction of future errors which is based on current rate of change.
The effect of increasing each ofcontroller parameters kp, ki and kd.
Typical steps for designing a PID controller are1. Determine what characteristics of the system needs to be improved.2. Use KP to decrease the rise time.3. Use KD to reduce the overshoot and settling time. This works in many cases, but what would be a good starting point? What if the first parameters we choose are totally crappy? Can we find a good set of initial parameters easily and quickly?
Damping frequency = 50.24 rad/secNatural frequency = 50.26rad/secDamping ratio = 0.019Settling time = 4.188 secRise time = 0.015 sec
Following parameters are obtained Damping frequency = 50.24 rad/sec Natural frequency = 50.26rad/sec Damping ratio = 0.019 Settling time = 4.188 sec Rise time = 0.015 sec During controller design, the proportional gain was set to 1. Increasing the Proportional gain to more than 1 increase the amplitude of the output signal.
Proportional Derivative (PD) controller can be used to control the vibrations. we were unable to actuate the cantilever beam because the output signals produced by the controller were too weak to produce mechanical vibrations and hence cannot be implemented without an amplifier, nevertheless we observed the output signals on Labview In order to accomplish it we need some amplifier to amplify the actuation given by PZT crystal
K. B. Waghulde et al. /International Journal of Engineering and Technology Vol.2(4), 2010, 259- 262. Journal of Vibration and Control March 2012 vol. 18 no. 3 366-372. http://www.kyu.edu.tw/93/epaperv6/93- 033.pdf Wikipedia – The free encyclopaedia.. National Instruments (NI) manual. Tutorials on Controller design by National Instruments (NI).