Recent content by james1234

I would be grateful for some direction on this. I wish to implement the following - Given a deterministic signal (the feedback signal of a closed-loop stable system) I would like to plot the power spectral density. The definition I am working with is this: Implementation (MATLAB): %...

Hi Miles, Thanks for the reference. Much appreciated. Its always a pleasure tracking down a good text. I'm not familiar with Phillip's and Harbor's book. I will most certainly pick up a copy. Jamie

I don't know why; I've always avoided nyquist plots like the plague. Looks like its time I convert. Cheers for the input!

Thanks Miles, Sorry my explanation wasnt clear. I was referring to the closed-loop stability of the systems and wondering how this might be determined purely from the bode diagram of the broken loop. Is this possible for systems with multiples phase/gain crossovers? The second system is...

Hi all, I would be greatful is someone could kindly enlighten me as to the correct interpretation of the appended bode plots. My understanding when interpreting bode plots is that we desire 0 gain where the phase is equal to or exceeds 180 degrees (marginally stable / unstable). In...

Finally, resolved :rolleyes: Thanks to all who took a look. I wanted to delete the post or mark it as solved to push it further down the 'list'. I don't appear to able to do either.. Cheers!

I have an equation (constraint) which I wish to solve explicitly in terms of gd (or more precisely a scaling factor of the vector gd) but I am unsure how to manipulate the equation σi(G) = |uiHgd|-1 Background: (please feel free to skips this. Much of this inforomation is I'm sure...

Hi Tim, I've been pondering your response for the past week or two. Clearly I've failed to grasp the fundamentals. Regarding your statement "you can't have ∂|v|/∂θ, they're in the same pair"?? Does this mean that you do not consider V to vary as a function of theta?! Now I'm really confused...

Hi Tim, thanks for your reply! well if it can't be solved then that does make me feel a little bit better.. :smile: A tiny bit anyway. However, when you say "if the other variable was r" are your referring to the relation V2 = u2+w2.. (thanks for the tip) Just in case a little more...

Evaluate partial derivative. chain rule?? I would like to represent the term identified in the image as (term 1) in terms of those partial derviatives that are known. unfortunately I just can't seem to wrap my head around it at the moment. :bugeye: A prod in the right direction would be...

Hi wh88, while uart has very kindly answered your question if you are doing a course in linear control you MUST (along with anyone else interested in this topic) look at the series of lectures by prof Madan Gopal on utube. I think root locus starts around lec 33. Likely you will find...

Yes certainly, Bodson's text "Adaptive control: stability convergence and robustness" briefly describes the form of the right (column) Hermite normal form on page 284 of the following link http://www.ece.utah.edu/~bodson/acscr/ where the hermite normal form is defined by P(s)=H(s)U(s) with...

Hi Ray, Thanks for your help! From what I understand the right hermite normal form is actually determined based on the relative degree of the respective elements (rational entries). i.e. the column operations are performed to reduce the relative degree of the lower triangular entries and...

Thomas Calc is definitely one of the best texts out there but for those starting out I would also highly recommend "Early Transcendentals Single Variable" by howard anton. Its perhaps a little more accessible and all though in some regards may lack the rigor of Thomas it is a brilliant textbook!

Hi Could someone please explain how to best handle rational polynomials in Maple? I have matrix of rational polynomials and for some reason Maple keeps grumbling i.e. "error, (in, linearalgebra:- HermiteForm) expecting a matrix of rational polynomials" The matrix I am working with is...