Hugh Lachlan Kennedy

10 Questions 272 Answers 0 Followers

Questions related from Hugh Lachlan Kennedy

How do heart-rate monitors work?

These devices have been around for a while now. Is there a consensus on the best way to do this, for low-cost/low-power computers and digitizers (e.g. wearable consumer tech)? I'm mainly...

04 July 2017 1,875 8 View

Does anybody know how Matlab's filter() function works behind the interface?

They say in the comments and documentation that it is implemented using a "Direct Form II Transposed" realization. But for FIR filters (i.e. when a = 1) I suspect it uses an fft() to do the...

11 May 2017 2,181 3 View

Are Bode and Nyquist diagrams useful tools for digital controller analysis and design?

I have been using both (Bode and Nyquist diagrams) to design simple digital feedback controllers for low-order SISO systems P(z), by analysing the loop transfer function L(z) = P(z)*C(z). But I am...

03 January 2016 856 4 View

Could you please help me with equiripple FIR filter design?

I would like to design a low-pass equiripple FIR filter, but I would also like to specify the (desired) group delay in the pass band; I would like to make this as low as feasibly possible, while...

25 October 2015 7,191 18 View

Does anyone have experience using Least-Mean-Squares (LMS), or some other recursive technique, for the estimation of a sinusoid's parameters?

I would like to estimate the frequency of a discrete-time (real) sinusoidal tone - with unknown amplitude, frequency and phase - in noise An LMS-type technique looks promising, for...

24 September 2015 8,008 6 View

What are the main classes of techniques to estimate the time delay between (or cross correlate) two digital signals/channels?

I would say there are essentially two main groups or categories of techniques that are commonly used to do this ... 1) Time domain e.g. a) normalized or 'regular' cross-correlation b) sum of...

03 August 2015 5,303 3 View

How does the 'maximum achievable' heart-rate change as cardiovascular fitness increases?

Let's say a person undertakes a program of high-intensity interval training (HIIT) on an exercise bike, with a heart-rate monitor, in a gym. This program involves 30 min sessions every day. The...

03 August 2015 5,757 17 View

Are the discrete Laguerre polynomials unique?

I have been using the Gram–Schmidt procedure to generate the discrete Laguerre polynomials, over the domain m = 0 ... +Inf, using an exponentially decaying weighting function w(m) = exp(sig*m),...

29 March 2015 6,550 3 View

Is a time-varying linear-combination of multiple stable conntrollers in parallel also stable?

I have a controller that consists of a bank of parallel sub-filters in the forward path of a feedback loop, cascaded with a stable plant. The input to the controller is the error signal (i.e. the...

22 February 2015 7,741 15 View

Is there a single design technique that can be used to derive the coefficients of digital IIR or FIR filters ?

There are methods to design digital IIR filters and there are other methods to design digital FIR filters. Can anybody suggest a single design framework that can be used to derive either IIR or...

01 January 1970 2,084 9 View