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Questions related from Ali Namadchian
I want the dynamical model of the compressor (ODE equations), so that I can model my controller. any one knows how to derive this model or is there any reference for that?
14 March 2025 2,195 0 View
I faced a very simple yet problematic phenomena when trying to find the bode plot of an unknown system with oscilloscope. as we know we can simply inject a signal to a system by a signal...
11 September 2023 7,983 2 View
By dynamical systems, I mean systems that can be modeled by ODEs. For linear ODEs, we can investigate the stability by eigenvalues, and for nonlinear systems as well as linear systems we can use...
28 August 2020 4,239 29 View
I know in the field of fluid mechanics, we mostly deal with PDEs such as Navier-Stokes equation. But what I want to do is to design a controller for flow control of a system consisting of a...
18 August 2020 6,639 4 View
Since the methods used in industry are more reliable than the ones presented in academic papers, I need to know the most commonly used adaptive PID control ( sometimes it is refered to as self...
26 May 2020 3,919 1 View
We know that mathematicians study different mathematical spaces such as Hilbert space, Banach space, Sobolev space, etc... but as engineers, is it necessary for us to understand the definition of...
14 October 2019 10,249 9 View
It is known that the FPE gives the time evolution of the probability density function of the stochastic differential equation. I could not see any reference that relates the PDF obtain by the FPE...
14 October 2019 1,372 8 View
In most of factories we have different systems and devices, as an example, in a procelain factory we have different furnaces, ball mills, presses and etc... Also in most of factories the proceture...
15 July 2019 889 5 View
for linear control systems x_dot=Ax+Bu the reachability set can be calculated using the Image of the controllability matrix, i.e R=([B AB A^2B,....,]) and reachability set=Im(R) when rank(R)=n,...
19 January 2019 6,172 3 View
In the well-known nonlinear system reference H.Khalil, Nonlinear Systems Third Edition in chapter 13.Feedback linearization, Khalil developed a theory for feedback linearization(Theorem...
12 January 2019 3,580 5 View
In control theory, when we can control the time-derivative of some state in the system, it means that we can control the state itself. consider the system x1_dot=x2 x2_dot=f(x,u) in the above...
09 January 2019 3,499 1 View
Imagine we have an ODE system x_dot=[f1(x,u), f2(x,u), f3(x,u),....fn(x,u)] where f1,..,fn are nonlinear functions of control input u and states x, x is member of R^n and u is member of...
07 January 2019 4,540 5 View
Spectral methods are one of the good tools to find the solution of the PDEs, I have a parabolic PDE like dP/dt=f(P, dP/dx1, dP/dx2, d^2P/dx1^2,..) where f could be f=a(x1,x2)*dP/dx1 +b (x1,x2)*...
14 November 2018 1,643 21 View
for deterministic systems, with defining proper terminal constraint , terminal cost and local controller we can prove the recursive feasibility and stability of nonlinear system under model...
11 November 2018 8,630 2 View
it seems that with solving the stationary form of forward Fokker Planck equation we can find the equilibrium solution of stochastic differential equation. is the above statement true?is it a...
11 November 2018 8,874 4 View
In many problems such as solving PDEs or optimization problems we need to calculate the numerical approximation for differentiation operation, nowadays in some packages such as Tensorflow the...
11 November 2018 9,135 67 View
when we use finite difference for descritizing the stationary version of Fokker Planck equation, the result will be a homogeneous equation like A*P=0, where P is value of probability at the...
07 November 2018 7,723 6 View
In the literature, most of the time, it is assumed that the system is slow enough and the time required for calculation of optimal control in each step of MPC can be neglected. it is a correct...
24 October 2018 9,209 1 View
when we need to solve the Fokker Planck equation (Kolmogorov Forward equation) with finite difference, we need to solve it in a bounded domain, (regardless of the dimension of the FPE), for more...
05 October 2018 8,561 12 View
what is the best method for constrained optimization ( in terms of the speed of the convergence an accuracy)? I want to train the parameters of the neural network with some constraints on the...
20 June 2018 6,667 15 View
for ODEs we can use the definition of stability, for example when the ODE is linear, by calculating the Eigenvalues or poles of the system the stability characteristic of the system can be...
20 June 2018 8,255 8 View
in process control in engineering, of course in many situations we need to control a system under a performance index (optimal control), where the system is exposed to uncertainty ( parameter...
20 June 2018 3,857 5 View
I am trying to train a complex system by neural net with Levenberg-Marquardt algorithm, it is faster than stochastic gradient descent, bot it is not fast enough. which training algorithm is the...
07 May 2018 9,489 7 View
in the literature, for solving an optimal control problem, most of the times we consider the system (ode equation) as a constraint and solve the optimal control problem, here is the question: if I...
02 March 2018 880 9 View
for example the dynamical system is x_dot=f(x,t,theta), theta is a random variable, which can have Gaussian, Gamma, uniform, multi modal Gaussian or any other probability distribution. is it...
22 January 2018 1,862 3 View
the gPC is used for uncertainty quantification, I find the gPC coefficients for Z=f(theta),where theta is a random variable(it may have any kind of pdf), I know the first coefficient a0 is the...
21 January 2018 7,874 6 View
In most of the literature for Generalized MPC, it is assumed that D matrix in state space model of the system is zero, I have a system with non-zero D (not a strictly proper system), what should I do?
27 December 2017 3,269 1 View
I need to solve the Fokker-Planck equation numerically. I need to know which method is the best method for solving this kind of PDE? among Finite difference, Finite element, Finite volume,...
15 December 2017 7,305 25 View
I am recently working on stochastic optimal control of nonlinear systems using model predictive control. Because of lack of laboratory equipment, I am not able to test my method on a real world...
02 December 2017 9,104 3 View
I am trying to solve an optimal control problem with PDE constraint. so in online optimization the solution of PDE can not be obtained fast enough (even with different numerical methods). I need...
08 October 2017 5,100 9 View
for more practical simulation of an optimal control problem, I need to consider the computation time which is needed for solving optimization in optimal control (regardless of discretization and...
31 August 2017 4,594 3 View
