# Read about control | 33 Discussions | Page 1

1. ### Is any form of animal torture OK?

I've been deeply disturbed by recent brain-related experiments that involve driving around insects, rats, and probably other animals like remote-controlled toys. No doubt this will lead somehow to some benefit for humanity. To cut straight to the point, do you feel (because this is a moral...
2. ### Converting linear state space into a transfer function

My questions are now... Do the steps of converting this space to transfer function include any laplace ???? or just we do get [SI-A]-1 and then transfer function is = C* [SI-A]-1 * B As [1 0] * [s-1/det -0.5/det ; 0.5/det s-0.5/det] * [0; 1] = -0.5/s^2+s+0.5 I mean do we need any laplace after...
3. ### Root Locus of Negative Feedback System

From my understanding, the root locus is only concerned with open loop gain. I figured this means you would ignore the negative feedback loop and calculate the root locus from just the plant's function Workings: zeros: -1 poles: 0, -2, -2, relative degree = 2 => 90-degree asymptotes meeting...
4. ### Modeling a third order system

Homework Statement Determine the parameters of the PI controller such that two of the closed-loop poles of the transfer function Gclr(s) correspond to the poles of a second order LTI system with the following specifications: i) overshoot S% = 25%; and ii) settling time ts(5%) = 120 s. Homework...
5. ### A Pontryagin minimum principle with control constraints

Hi, I am trying to solve a control problem where I have to minimize the fuel consumption of a vehicle: $$J=\int_{0}^{T} L(x(t), u(t),t) + g(x(T),T)dt$$ ##L(u(t),v(t))=\sum\limits_{i,j=0}^{2} K_{i,j} u(t)^i v(t)^j ## is convex (quadratic) and the term ##g(x(T),T)## is to have a constraint in the...
6. ### How do I control this heater?

So I have a coiled (Nichrome) heating element that's rated at 120VAC 60Hz. (Resistance of 14.4Ohms) I am trying to use this heating element to warm up air blowing across it. I will have thermistor on the outlet end to monitor the temperature of the output air. This heater is coiled inside of a...
7. ### Compensator Design in system control

Hello, in my final project for System Control i have been stuck for some time on this following task What i cannot figure out is how to make all these condition work at the same time. When I tried designing a PD controller in sisotool or matlab for the i and ii part it worked but i couldn't...
8. ### How do you control an Electronic Butterfly Valve with PID

The butterfly valve I have is controlled by sending voltages to it. It accepts 0-10V and maps a specific voltage to a specific position from completely closed (zero degrees) to completely closed (90 degrees). To clarify/reiterate it is not controlled by a servo motor. I am using this valve to...
9. ### Design of High Pass filter to eliminate an instability in my control system

HI, i have a first order controller (ts/ks+k) which contain some oscillations and its settling time is very huge, i wanted the controller to have settling time of 10seconds and remove the oscillations. in order to remove the noise and get the expected settling time i added a filter ( s/cs+1)...
10. ### HVAC DIY glovebox or closed fume-hood?

Hi everybody, I'm a PhD student working on solution-processed kesterite PV cells. The material is spin-coated and I personally believe that its wetting properties are influenced by environmental parameters like temperature and humidity. To control these parameters, or at least reduce their...
11. ### Control theory

Good afternoon people; recently I decided to give a study break from control engineering; now I'm back. I'm studying again control theory and I see some good results. By the way I got stuck in a topic called root locus method. Now my issue is not about how to sketch the root loci graph (BTW I...
12. ### Determining the sign of control derivatives

I'm having quite a deal of trouble trying to figure this out. Say, for example, you wanted to have a statically stable aircraft. How do you determine what the signs (positive or negative) of the control derivates need to be for this condition to be satisfied ( CXα, CZα, Cmα, Cmq, CZδe, etc) ?
13. ### Find transfer function in relation to the disturbance

Suppose you are given a first order system whose transfer function is HP(s) = KP/(TP*s + 1). Now, you want to control this system using a standard P (proportional) controller whose transfer function is HR(s) = KR (a proportionality coefficient). There is also disturbance that acts upon this...
14. ### Understanding operation of specific SMPS example (is it a flyback?)

I don't have much spear time at the moment, but I came across a SMPS diagram in this thread: https://www.physicsforums.com/threads/quick-question-about-inverter-tx-order-wrt-mains.870309/ And I was trying to figure it out, and I don't want to forget about it before I do. So I was wondering if...
15. ### Calculate gain of a transfer function without root locus

Hi, Having a bit of trouble with this question: "Assuming a proportional controller is used, determine the gain to achieve a damping ratio of 0.5, for the following transfer function. Hence calculate the associated natural frequency and oscillation period. G(s) = -4(s+0.4) / s^2+1.6s+14." I...
16. ### Can I use two AC TRs with ONE neutral at sec. and prim.?

The situation: I have one BMS (Building Management System) controller supplied from TR1 (220Vac to 24Vac transformer) and provides an analog control signal (0-10VDC) with the (-) of that DC being the same as the Neutral of the controller (from TR1) and should control a valve actuator. The...
17. ### Identifying type of feedback by looking at bode plot

Homework Statement Below is the bode plot of return difference, 1+C(S)P(S) in a feedback system. Identify the frequencies where the feedback is large, negative, positive and negligible. P(S) = \frac{100}{s^2+2s+1} C(S) = \frac{220(s+50)}{s+200} Homework Equations Bode Plot, Feedback The...
18. ### Using expm of matlab to plot state responses

Homework Statement The state space model of a nonlinear system is x'_1(t) = 2x^2_2(t) - 50 x'_2(t) = -x_1(t) - 3x_2(t) + u(t) where x_1(t) and x_2(t) are the states, and u(t) is the input. The output of the system is x_2(t). Find the zero input response (u(t) = 0) of this system linearized at...
19. ### Finding the state space model of a nonlinear system

Homework Statement The state space model of a nonlinear system is x'_1(t) = 2x^2_2(t) - 50 x'_2(t) = -x_1(t) - 3x_2(t) + u(t) Where x_1(t) and x_2(t) are the states, and u(t) is the input. The output of the system is x_2(t). Find the state space model of this system linearized at the...
20. ### Calculate dilution to create new specific gravity

I am trying to make specific gravity controls using ethylene glycol and DI water. Ethylene glycol has a specific gravity of 1.113. I want to know the weight in grams of EG to add and then QS with water to achieve 50 ml of a solution with a specific gravity of 1.002. I need a formula please...
21. ### Induction machine slip control

Hi, Say you wanted to have a generator or motor stay at near 90degrees for maximum torque while generating or motoring, over various loads or over various supply frequencies. I assume there is some established method of controlling this (varying the rotor resistance with feedback perhaps?) does...
22. ### Cars attaching to one another using magnetic force

hi, i'm doing a little research and in need of help since i'm not so talented in physics.. :( Is it possible to attach 2 cars with magnetic force so that they can be driving as one? (one car in the front and another car behind) I think it can be done with magnetic force but how.. Also, Is it...
23. ### Mathematical modeling of the deflection of a rod

A rod is radially mounted on a motor shaft and provided with a flat end plate. By turning movement, the end plate will touch a pointed object, and the angle turned is measured.By the torque of the motor during acceleration and deceleration, a vibration and deflection happens on the rod. The...
24. ### Temperature controlling system with peltier battery?

Hello everyone! I have a thesis to design a temperature stabilizing(controlling) system for solar cells.I need to use 12V Peltier battery and a simple pc fan.Any further help is appreciated.
25. ### Coherent Control of Fusion?

http://www.iflscience.com/space/molecules-have-been-built-using-laser-beam-first-time [Broken] Is there a way that fusion could be achieved with coherent control like this? If it can build molecules couldnt deuterium-deuterium be achieved?
26. ### Simple Symplectic Reduction Example

Homework Statement I'm struggling to perform a symplectic reduction and don't really understand the process in general. I have a fairly solid understanding of differential equations but am just starting to explore differential geometry. Hopefully somebody will be able to walk me through this...
27. ### Inverted V Tail Simulation

Hi Guys, I am working on a design trying to control a model through inverted V-tail/ruddervators only. No aileron or horizontal stabilizer. Do you think it is possible as apparently I am facing instability issues. Any guidance in this regard would be helpful. Thanks
28. ### Simulink help for getting a frequency I can use as an input

Ok, say I have a sine wave block that has a frequency of 60Hz. What can I do to get that frequency as a number so I can use it as an input to another block? I've tried various things such as a "sign" block that counts when it switches from positive to negative and then a counter that resets...
29. ### Computed Torque Control vs. PID

I'm working on a pantograph device, which is not a linear plant, and implemented 2 different control schemes. First one is computed torque; For this control technique, I modeled nonlinear terms in the equation of motion and canceled them by injecting their model within the control input, which...
30. ### How to tune the PID parameters using Fuzzy Logic?

I previously used the Ziegler method to tune the parameters of my PID controller to control my robot's position. I then implemented fuzzy logic for self-tuning the parameters. I have two inputs to the fuzzy logic controller; one is the position error and the error rate. I know that my problem...