In my engineering journey, I first began utilizing median filters again in 1994 when working with programmable logic to debounce swap inputs. Debouncing is a method used to eradicate the noise or chatter brought on by mechanical switches. Whereas an alternate answer is to make use of a digital monostable delay, this introduces an uneven delay — one edge experiences an extended delay than the opposite. In distinction, a median filter affords equal delay on each transitions and excels at suppressing high-frequency swap chatter that arises in the course of the mechanical switching course of.
A median filter is a straightforward but highly effective method that works by filtering out noise and sustaining the integrity of sign transitions. Historically, when debouncing switches, one may use a digital monostable delay, which provides an undesirable delay to 1 edge transition. With a median filter, nonetheless, the swap’s bouncing noise (fast state adjustments because of mechanical imperfections) is filtered extra successfully, because it suppresses high-frequency oscillations whereas preserving the true sign.
On this context, a median filter could be carried out as a shift register with logic. The swap’s state is sampled at common intervals, and…