The tag has no wiki summary.

learn more… | top users | synonyms

0
votes
0answers
32 views

Perfect system identification or am i doing something wrong?

I am using MATLAB to identify a system. The problem with my method is that my result is perfect. I get a nearly 100% fit, which make me wonder if what I am doing is correct. I feed a sine sweep with ...
1
vote
1answer
54 views

What is the low-pass filter that gives minimal transient response?

As title says, what is the low-pass filter that gives minimal transient response? By minimal transient response, I mean minimal settling time with reference to very tiny amount of divergence of ...
0
votes
1answer
23 views

Inputs for system identification

What effects does have a different input such as impulse, step, sine sweep etc. on performing a system identification? I mean what is up/down side, and which one is best, and why chose one rather ...
0
votes
0answers
5 views

Discrete dataset into to continous dataset?

I am trying to perform system identification on a system.The input i am going to provide is sinewaves with different frequencies. I sampled a sine wave with 100 Hz which is used a input for the ...
1
vote
1answer
57 views

What kind of filter is this?

Is this filter a BPF? $$\dfrac{z}{z-a}$$ where $a$ is some complex number? If we put a pole somewhere on the unit circle it will emphasise a certain frequency, is that right?
0
votes
0answers
12 views

Given the digital filter, how does one minimize transient reponse while keeping steady-state resposne?

Suppose the digital filter is given by $H(z)$. If the input is $0$ for $n<0$, then when input occurs at $n =0 $, transient response will necessarily be there. So I want to minimize this transient ...
0
votes
1answer
19 views

input output read/write frequency

I am trying to identify a system based on input/output response and thereby estimate a transfer function. I generated a frequency sweep function in Mathematica which gives me the discrete values of a ...
0
votes
1answer
29 views

Do FIR filter have any application in control theory?

I know about IIR filter as discrete pendent to transfer functions in the Laplace domain. So it is actually quite simple to convert the function of the control system and finally receive the discrete ...
1
vote
1answer
66 views

Root Locus for a system

I know this subject tends more to control theory but I am certain its part of the global knowledge basis for engineers, thus I believe I can find the answer here. I'm trying to draw Root Locus for ...
1
vote
1answer
84 views

What is the physical interpretation of the dB scale on a bode plot and what is a negative dB?

I have no physical interpretation of the Bode plot. What does it mean for a bode plot to have negative dB over its entire duration on the log-scale frequency?
0
votes
1answer
46 views

What is the difference between a sampled time system and a discrete time system?

I am trying to evaluate whether I should control a system in simulink using sampled data system or discrete time system. The discrete model is as follows: The sampled time system is as follows ...
0
votes
2answers
40 views

Why is my bode plot showing periodic behavior?

I found something very interersting when I was trying to simulate a discrete time system. So first I discretized the continuous system $G(s)$ using "c2d" function and "dbode". The resulting bode ...
0
votes
0answers
17 views

Stability of an unstable system using nonlinear element. Is it possible or not?

Say there is a system with open-loop transfer function G(s)=1/(s−1) . The system is definitely unstable. If I put any nonlinear system in cascade with G(s) and from the output, a negative unity ...
3
votes
2answers
79 views

How to intuitively understand the state space formulation of discrete time system?

The SS formulation of DT system is given by $$x[(k+1)T] = Ax(kT) + Bu(kT)$$ $$y(kT) = Cx(kT) + Du(kT)$$ Note: T is the sampling period and often omited Can someone explain to me why the state ...
2
votes
1answer
66 views

For a standard second order transfer function, what is the equivalent time domain significance of $\zeta>0.707$?

In frequency domain $\zeta>0.707$ implies no resonant peak in frequency response. But I am unable to correlate what is the exact time domain effect of this? If $\zeta=0.707$ acts like an ...
1
vote
2answers
44 views

Does the system matrix being singular tell us anything about the system?

If we have a linear system, represented in State Space and the A matrix is singular (det(A) == 0), can we expect any special properties from the system?
0
votes
0answers
35 views

Choosing an appropriate PRBS for system identification

The system im investigating can be approximated with a First Order plus deadtime model. I'm currently using step and doublet pulses(two steps with opposite sign) to excite the system. I'd like to use ...
1
vote
1answer
48 views

Iterative Kalman filters and system parameters estimation

i am working recently on a project in which i want to implement a Kalman filter as being an observer, and i couple this observer with a state feedback controller that produces control actions ...
0
votes
1answer
56 views

How to periodically estimate states of a LTI if the output is measured irregularly?

How can I periodically estimate the states of a discrete linear time-invariant system in the form $$\dot{\vec{x}}=\textbf{A}\vec{x}+\textbf{B}\vec{u}$$ $$\vec{y}=\textbf{C}\vec{x}+\textbf{D}\vec{u} ...
1
vote
1answer
50 views

Wavelet transform in control systems

In control systems, the Laplace transform is often used to analyze the stability and the performance of LTI system. For instance, the LTI system is stable if and only if the transfer function, which ...
-1
votes
1answer
81 views

Describing Function for non-symmetric Saturation Model

Let's talk about a standard saturation model: with bounds $bound_{lower}$ and $bound_{upper}$. So in this example the output $y$ will be: \begin{equation} y(u) = \begin{cases} ...
0
votes
1answer
52 views

Iterative blind sinus signal suppression

There are two real signals in the form of $A_i sin(wt+p_i), i=1,2$. Suppose frequency $w$ of both the signals is the same and amplitude $A_i$ and phase $p_i$ are different. The first signal has ...
1
vote
0answers
37 views

Does the integrator in a PID controller removes the disturbance?

I am reading "Small Unmanned Aircraft: Theory and Practice" (page 7). We have the following Transfer Function (TF): $\phi(s)=\frac{a_{\phi 2}}{s(s+a_{\phi 1})}(\delta_a(s)+\frac{1}{a_{\phi 2}}d_{\phi ...
1
vote
2answers
71 views

Differences between two closed-loop systems

What could I say about stability of those systems by looking at the scheme? System 1 System 2 $y_r(s)$ is input, $a(s)$, $b(s)$, $p(s)$, $q(s)$ and $r(s)$ are some polynomials and $y$ is output. ...
1
vote
1answer
49 views

Existence of transfer function

This is my system. Is there a way to find a transfer function? I can’t help the YR(s) going inside B(s) without being sampled, and I think this is the problem. Any help?
5
votes
2answers
301 views

A good textbook for designing signal filters

Since a couple of months ago I started being actively involved in the area of control of dynamical systems. In most cases, designing a controller for a given dynamic system will require the ...
3
votes
1answer
420 views

AutoExposure with nonlinear camera: Non linear proportional PID?

Now I', wondering how to best implement a control algorithm for it. I tried using a PID controler but started with a simple P-control first. The problem is, that when using the equation ...
2
votes
2answers
448 views

Kalman filter with accelerometer with DC offset

Goal: For a particle moving uniaxially, to estimate position ($d$) and velocity ($v$) from noisy acceleration ($a$) and very noisy position (GPS) measurements using a Kalman filter. Catch: The ...
0
votes
0answers
40 views

construct 2-state observer

I have position $\theta(s) = \frac{s^2+1}{s^4+2s^3+3s^2+4s+5}$ and velocity $\dot\theta(s) = \frac{s(s^2+1)}{s^4+2s^3+3s^2+4s+5}$. How do I construct 2-state-observer with sampling time $T_s$? ...
1
vote
1answer
598 views

Inverse system in Simulink

I have a inverse system: $G(s)= s^2 + 2s + 3$. How do I apply it in a Simulink model? (the transfer function is only accepted if and only if the order of the numerator < order of denominator).
3
votes
0answers
142 views

Digital control: Exercise solution

Can you help me (show me how) to solve the following exercise? For the process with transfer function $G(s)=e^{-2s}/(s+1)$ design a digital controller with sampling time $T_{s} = 1$ that meets the ...
2
votes
1answer
442 views

State Space Observer Control

I am attempting to implement observer based state feedback in C and can't figure it out. Here is pseudocode of the algorithm: ...
2
votes
1answer
161 views

response of algorithm in non-equidistant time

We are investigating ways to test a control algorithm. The algorithm has a non-equidistant track of input data (i.e. not every sample is valid, and we know it), and should output a series of ...
3
votes
0answers
408 views

How do I check controllability and observability using Gramian matrixes?

I have a pending exam and this is one of the must-know questions. It will be about checking controllability/observability of a simple MIMO linear system, using Controlability Gramian/Observability ...
2
votes
0answers
84 views

Optimal inference for nonlinear state space models

When considering a linear-Gaussian state space model, it is often referred that, optimal inference is tractable which is very rare in state space models. When considering a nonlinear state space ...
8
votes
0answers
120 views

Estimating the input to a system from a system state using EKF

[ Cross-posted from: http://math.stackexchange.com/questions/164169/estimating-the-input-to-a-system-from-a-system-state ] I have a system for which I have obtained a non-linear time-varying ...
7
votes
2answers
856 views

How to do prediction using frequency domain data?

Both linear regression and Kalman filtering can be used to estimate and then predict from a time domain sequence of data (given some assumptions about the model behind the data). What methods, if ...
2
votes
2answers
98 views

survey/book on adaptive/self-tuning of PI controllers?

Can someone point me towards a good book or survey article on adaptive/self-tuning of PI controllers? All I can find online are articles which are either vague or heavy on theory.
9
votes
1answer
530 views

How to deal with a negative pole (unstable) in the pre-filter of a control system?

So while answering how to design a PI controller for a first order time delayed system (Question Here ) Here is the closed loop equation to a control system: $$ G_C(s) = ...
7
votes
1answer
524 views

What is the “waterbed effect” in control system design?

I recently stumbled across some notes on the "Waterbed effect" in some notes by A. Megretski for an MIT course on "multivariate control systems". Here's an excerpt: A common effect, usually ...