Control engineering or control systems engineering is the engineering discipline that applies control theory to design systems with desired behaviors. The practice uses sensors to measure the output performance of the device being controlled (often a vehicle) and those measurements can be used to give feedback to the input actuators that can make corrections toward desired performance.

• Qian Wang

  Piecewise linear control

  What are t he latest results on the piecewise linear control?

  Recent replies ⋅ Show All (1)

  • 
    Andrés Gabriel García replied

    Dear Qian Wang: No further results since 2008 except for the works (as far as I know): 1_García, A., and Agamennoni, O. (2008), “Continuous Piecewsie Linear Control for Nonlinear Systems: TheDear Qian Wang: No further results since 2008 except for the works (as far as I know): 1_García, A., and Agamennoni, O. (2008), “Continuous Piecewsie Linear Control for Nonlinear Systems: The Paralle Model Technique,” in Selected Papers from WSEAS Conferences in Instanbul, May 27-30, WSEAS, WSEAS. 2_García, A.G., Agamennoni, O.E., and Figueroa, J.L. (June 16 - 18, 2009), “Applying Continuous Piecewise Linear Approximations to Affine Non-Linear Control systems,” in Preprints of the 6th IFAC Symposium on Robust Control Design, Haifa, Israel. We are preparing some very deep results as a continuation of those papers. Please let me know if I can be of any futher assitance. Best regards, Andrés García, Phd (agarcia@uns.edu.ar)

    3 hours ago
• Yong Kuen Ho

  Robustness of a control scheme

  How does one usually evaluate the robustness of a controller?

  Recent replies ⋅ Show All (11)

  • 
    Chung-Han Hsieh replied

    There are many approaches for solving robustness problem. In general, the most frequently used method is applying "small-gain theorem". This tools is a powerful tool for solving LTI system'sThere are many approaches for solving robustness problem. In general, the most frequently used method is applying "small-gain theorem". This tools is a powerful tool for solving LTI system's robustness issue. The detailed discussion can be founded in many literature and books easily.

    3 days ago
• Zainah md zain

  How to convert second-order chained form to second order power form?

  Second-order chained form, power form
• Dirk Kok

  How is the voltage controlled across the input capacitor in a buck converter?

  In a basic buck converter (see attached) the input is often set as a battery and the output load as a resistor and the input resistor (plus ESR) is often left out. This is fine to establishIn a basic buck converter (see attached) the input is often set as a battery and the output load as a resistor and the input resistor (plus ESR) is often left out. This is fine to establish functionality regarding dc and small signal analysis around stability. But when the input is a -for example- motor controller (i.e. a current source) and the input capacitor is put in place and the output load is a battery there is a change in the circuit behaviour. Currently I am using SimPowerSystem to model the buck converter according to the above described setup using the current source to simulate the motor controller under regenerative braking conditions and find that when I am using peak current control the voltage of the input capacitor does either one of two things depending on the reference value I set. 1. the reference current is set to the current supplied by the current source (CS) --> the voltage across the input capacitor shoots up according to: i = C*dv/dt During the off stage the CS supplies its value to the capacitor only and during the on stage the inductor current is equal to the CS current and thus no current is taken out of the input capacitor and thus the voltage keeps rising. 2. the reference current is set to double the supplied current --> the voltage drops down the match the output voltage as set by the battery, the dutycyce remains at 1 (on state) and the inductor current follows the supplied current. But with no switching happening this behaviour is no longer a converter in that the input voltage is not converted down to the output voltage. The main thing I notice about this effect is that the turning point seems to be so abrupt? This is what I see happening and makes sense with the theory. What I would want to know is: Is this realistic behaviour in real life? And if so, how do people work around this? i.e. How is the voltage controlled across the input capacitor in a buck converter? Or is there some more control on the motor controller side that keeps the voltage at a more fixed point through for example the use of a very large capacitor? I am talking about a motor controller where I assume the motor controller to be a capacitor followed by a classic inverter topology to control induction motors. sincerely yours,

  
• Srikanth Vasudevan

  How to find the sliding mode observers (SMO) gain?

  I am using SMO for speed sensorless control of PMSM. Do you have any idea about how to calculate the sliding mode observers gain?

  Recent replies ⋅ Show All (8)

  • 
    Srikanth Vasudevan replied

    Thanks Dr. Shibly for your comments. While working on it i have noticed this . Let me try more on it

    18 days ago
• Mari Muthu

  Implementing the bandwidth limited derivative kick in a robust PID controller

  Implementing the bandwidth limited derivative kick is major drawback in my project
• Marco Aurelio Aguiar

  References on Frozen Riccati Equation and similar control methods

  I am interested in Control laws based on lyapunov applied to nonlinear system using linear approximation. I first met Frozen Riccati, maybe there is another control law that might worth a look. CouldI am interested in Control laws based on lyapunov applied to nonlinear system using linear approximation. I first met Frozen Riccati, maybe there is another control law that might worth a look. Could someone give references?

  Recent replies ⋅ Show All (15)

  • 
    josé Ragot replied

    Another possibility : transform your nonlinear system into a multiple model form and then apply Lyapunov approach on the multiple model. You can see on my www pageAnother possibility : transform your nonlinear system into a multiple model form and then apply Lyapunov approach on the multiple model. You can see on my www page "http://perso.ensem.inpl-nancy.fr/Jose.Ragot/" some works about that.

    Apr 19, 2012
• Zainah md zain

  Anyone use Scilab software for control system?

  Scilab

• Post protected

  Join ResearchGate now to read this post.

  Recent replies ⋅ Show All (28)

  • 
    Mohamed jasim Mohamed replied

    No new approach, but in all context there are some news.

    Apr 6, 2012
• Adolfo Silva

  Digital Control -- Which are the new trend topics in digital control?

  Nowadays we have faster sensor I mean higher sample rates with good resolutions! And the microprocessor are faster than sixty's when the digital theory was developed! That time they have problemsNowadays we have faster sensor I mean higher sample rates with good resolutions! And the microprocessor are faster than sixty's when the digital theory was developed! That time they have problems with quantization, sample rate and so on! But today this problems "vanish" or are less intense because the technology! So what are the new trends in digital control?

  Recent replies ⋅ Show All (6)

  • 
    Emmanuel Delaleau replied

    I think that control has evolve a lot in nonlinear continuous-time design since 20 years : flatness-based control, control based on Mikusinski operational calculus, fast algebraic estimationI think that control has evolve a lot in nonlinear continuous-time design since 20 years : flatness-based control, control based on Mikusinski operational calculus, fast algebraic estimation technics, model-control. All of these have demontrated their robustness an superriority. Could you send references on what you have in mind ? (synchronization, sector of industry...)

    Apr 3, 2012
• Mohammad Reza Yeganegi

  How can I find the controllability conditions or controllability distribution for discrete time nonlinear state-space system?

  I need to find the controllability distributin for the following discrete time nonlinear state-space system: x(t)=f(x(t-1)+B(t)u(t) y(t)=g(x(t)). There is some algorithm for continuous timeI need to find the controllability distributin for the following discrete time nonlinear state-space system: x(t)=f(x(t-1)+B(t)u(t) y(t)=g(x(t)). There is some algorithm for continuous time nonlinear system however I couldn't find the discrete time case.

  Recent replies ⋅ Show All (7)

  • 
    Hebertt Sira-Ramirez replied

    Linearity or affine character in the control inputs doesn't make much sense in discrete time nonlinear systems. This is lost at the second iteration. The concept of vector fields does not directlyLinearity or affine character in the control inputs doesn't make much sense in discrete time nonlinear systems. This is lost at the second iteration. The concept of vector fields does not directly apply to discrete time nonlinear systems either, much the less the concept of distribution. What you deal with is control parameterized transition maps from instant to instant. However, differentials, or Khaler differentials, and their "linear subspaces" may be used to chacterize a lot of concepts in this field. You may then take their duals and identify these objects as vector fields. The geometry is of a quite different flavor and non-intuitive, though. A good reference is earlier work by M. Fliess and El-Asmi (see also "Reversible linear and nonlinear discrete-time dynamics" in ieee explore. A beautiful paper by J. Grizzle may be found in http://scholar.google.com.mx/scholar_url?hl=es&q=http://citeseerx.ist.psu.edu/viewdoc/download%3Fdoi%3D10.1.1.34.3800%26rep%3Drep1%26type%3Dpdf&sa=X&scisig=AAGBfm3uEBYrXWT4_tJ0L19KwjfOy9-EvA&oi=scholarr&ei=dwF6T7yVF4bq2AX8pbm1Bg&ved=0CBoQgAMoAjAA). Search also under J.F. Pomet et al, Aranda et al. More recently: see papers by C. Moog, Ulle Kotta etc.

    Apr 2, 2012
• Sutha Sangapillai

  Plotting multivariable Nyquist plot manually for TITO system

  Is there any MatLab code available to do this?

  Recent replies ⋅ Show All (2)

  • 
    Sutha Sangapillai replied

    for any 2 input 2 output system inwhich any one of the transfer function having RHP zero..

    Mar 30, 2012
• Ali Umair Khan

  Which is the most computationally undemanding evolving fuzzy schemes? 1 eTS evolving takagi sugeno 2 FLEXIS

  Evolving fuzzy modelling
• Zainah md zain

  What is the difference between Barbashin’s theorem and Barbalat's Lemma?

  Stability theorems.

  Recent replies ⋅ Show All (2)

  • 
    Zainah md zain replied

    Thank you very much sir

    Mar 26, 2012
• Sudibyo Bin Sakhidi

  What are some recent optimizers for linear and non linear Model Predictive Control?

  NMPC commonly use SQP and PSO as optimizer, while the linear MPC commonly use QP and lest square optimisation, what are other optimisation methods for Model Predictive Control?

  Recent replies ⋅ Show All (2)

  • 

    Comment protected

    Join ResearchGate now to read this comment.