Developing a novel biquad multifunction filter model and deploying on real-time controllers

This paper proposes a novel multifunction Biquad filter model, which is easily implemented using state space representation and can be deployed in real-time systems. In this design, some coefficients for this filter are considered as input, and by applying and tuning them properly, the desired functionality of the user is achieved. The Biquad filter is a universal filter that can be used to achieve filters such as low-pass, high-pass, band-pass, lead-lag, and notch. In fact, the other types of filters will also be achievable using this filter design, and this paper describes how to access them through the Biquad filter. Actually, these filters can be easily obtained by changing the parameters. The developed filter is first simulated in MATLAB/Simulink software, and then the algorithm is applied to the experimental plant using a real-time implementation using LabVIEW. The simulation and experiment results confirm the presented approach is successful. This filter has no restrictions for use in any frequency range. Increasing the value of the quality factor (Q) is an important parameter in reaching the desired response for this filter, which can be easily adjusted. The filter performance is evaluated using the total harmonic distortion (THD) metric, which equals 3.44 %, which verifies the appropriate design of the filter. With proper tuning, this filter can also attenuate the interfering frequency factor by >99 %, which is a desirable performance.This filter can be used in cases such as bioinstrumentation, vibration control in robotics, or motor drives, etc.