Questions tagged [control-engineering]
Questions about the models and theories of control engineering and the application of control theory to design systems with desired behaviors.
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questions with no upvoted or accepted answers
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On a Diesel/hydraulic DMU train what exactly does the “go faster” lever control?
Let's say that you are driving a Diesel Multiple Unit† with either mechanical* (i.e. an actual gearbox with multiple ratios) or hydraulic (i.e. two or more torque converters) transmission. When you ...
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Questions regarding Cornering Stiffness for RC Car
I am a bachelor's level student tasked with modeling the vehicle dynamics of an RC Car that will be made to drive autonomously. I lack prior experience or particularly specific education with vehicle ...
user14808
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I have a problem with my representation of roll in Simulink
I am currently an engineering student and a member of the aerospace club of my engineering school (ESILV) which is called LéoFly. We’re a team of 12 students and are building a Fusex (...
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Need some advice, control system animation. Appreciate some help!
I would like to have a 3d simulation of a helicopter landing on a ship.
I thought about using matlab for this, as a far as I know you can connect models from Simulink to virtual worlds using blocks, ...
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What is the most common control method in Underfloor heating?
I am trying to research the common methods on an underfloor heating system that are available in the market.
I know there are usually,
On/Off control to control the flow of water into the pipe
...
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Is the viscosity solution of Hamilton-Jacobi equation of practical use in optimal control?
My understanding is, given an optimal control problem, one can show that the optimal cost satisfies a Hamilton-Jacobi PDE and use dynamic programming to figure out the optimal control. However, ...
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Fluid dynamics of non interacting tanks in series
I have a system like this:
and I have to estimate the height of the lower tank.
First of all, I'm considering that I have a non-viscous, incompressible fluid in steady flow.
Base apertures
The ...
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understanding observers and estimators
I have seen several forums related to this question about the difference between observers and estimators in control theory and could not understand it clearly. I wanted to know how the state ...
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what's wrong with this robust control scheme?
I'm learning how to control a double integrator with $H_\infty$.
my model is simply
$$\begin{gather}
\dot{r} = v \\
\dot{v} = F/m \\
r(t_0) = 0\text{ m}, $v(t_0) = 0\text{ m/s}, m = 1000\text{ kg}
\...
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PI or PID-regulator for control system with hysteresis relay in inner loop
I have such control system (sorry for rough drawing :) )
$G(s)$ - stable object with proper transfer function.
$1/s$ - integrator.
I need to clarify, how synthesized PI or PID controller for such ...
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Modeling rigid body dynamics: Trouble with equations, encountering nonsense answers
Hi, I am working on modeling a simple rigid body dynamic system through a certain range of motion. Here is the picture of the system.
I am trying to solve the system for the variables $x_1'', y_1'', ...
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Relationship and interpretation of "discrete" and "continuous" covariance matrices in Kalman Filtering
I am quite confused about the interpretations/implementation of the system and measurement noise covariance matrices for the continuous and discrete time Kalman Filter. What I want is to initialize ...
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Mathematical transformation of a heading angle to a roll angle
I'm trying to understand a function in a SIMULINK example of a path following UAV simulation. The gist is that, the UAV Waypoint Follower block provides a required heading from a list of waypoints and ...
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Kalman Filter by Orthogonal Projection
I'm working through the derivation for the Kalman filter using orthogonal projections. It's pretty intuitive that if we want to generate the best linear estimate for an $n$-vector $x$ using some $m$-...
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LQR Implementation in MATLAB
I am trying to implement a simple LQR controller in MATLAB for a purely deterministic system. The code is shown below:
...
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Problem reading control effort frequency response plot
I am trying to plot the frequency response control effort of a control scheme in Matlab, and in particular I want to do this for different values of tau, which is a constant used to add a pole at high ...
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3 DOF SISO state space control
As part of a control systems course I have to implement control for a 3 DOF SISO mass spring damper model of a robotic cutter arm. The arm is to follow a 5Hz triangle wave reference which is ...
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Sector determination of a nonlinearity and passivity
This a not a homework or any similar task.
Regarding determine the determination of static nonlinearity, I know that one can draw two lines that contains the nonlinearity part. For instance for three ...
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Determining damped frequency and damping ratio from time domain data
I have some time domain data which are responses of an aircraft to various inputs (example: time vs. bank angle for lateral stick pulse input). I need to compute the effective damping ratio and damped ...
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Purification of wet-process phosphoric acid
I'm doing my senior design class and I have design a chemical plant that produces phosphoric acid by reacting phosphate rock with sulfuric acid. The phosphate rock has a lot of impurities, some of ...
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Finding the zeros for a PID controller
I would like to know what I am doing wrong for this PID controller design problem. I have all the parameters calculated ($\zeta$,$\omega_n$,$\sigma$...) and I have my target point set up. But now I ...
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Is there a way to obtain a circuit of some sort given a Nyquist plot?
I have some transfer functions and I was wondering if it would be possible to approximate this to an electric circuit equivalent. For example, given the Nyquist plot below, is it acceptable to ...
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Is it theoretically possible to control an continuously flexible inverted pendulum?
We can control an inverted pendulum relatively easily with PID.
We can control a double-inverted pendulum with more sophisticated methods.
Lately, a triple inverted pendulum was controlled, with 56 ...
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Inverted pendulum PID: controller causes cart to move at constant velocity?
I am trying to understand the PID controller of an inverted pendulum on cart system through this MATLAB article: https://ctms.engin.umich.edu/CTMS/index.php?example=InvertedPendulum§ion=...
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Relationship between the infinity norm of estimation error and the trace of estimation error covariance matrix in Kalman filter
I am working on designing an interconnected distributed control system. In this system, I need to use Kalman filter because the measurements are noisy.
I have two questions:
1 - What is the ...
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How do you generate an impulse signal in a mechatronic system?
Background:
I have a piezoelectric force transducer that I am using to measure the force produced by a combustion reaction in a tube. The issue is that there is a lot of ringing that occurs during the ...
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Stability from Gain and Phase Margin
I know that a system with positive gain and phase margin is a stable system. And the one with a negative gain and phase margin is unstable. What will a system with negative phase margin and positive ...
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Why using Tyristor (SCR) for inverting the DC voltage in HVDC systems?
In High Voltage 3 PHASE Transmission Systems the voltage needs to be rectified (from the AC generation source to DC), transmitted, and then inverted back (From DC to AC). For doing this, usually LCC (...
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Converting nonlinear system into equivalent nonlinear of the Byrnes-Isidori normal form
I have a nonlinear system (Ball & Beam) which is described by the following equations of motion:
$$ \ddot{y} + \frac{mg}{a} \sin(θ) -\frac{m}{a}y\dot{θ}^2 = 0 $$
$$ \ddot{θ} + \frac{2m}{b}y\dot{...
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Generating Linear Velocity Movement?
In preparation for a Fluid Mechanics experiment, I am looking for a simple commercial ready made
apparatus to generate a linear velocity trend to prove a new theory:
https://aip.scitation.org/doi/abs/...
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avoidance with LQR
I'm interested in using linear quadratic regulators (LQR) to model prey avoidance behaviors. I want to adapt the LQR algorithm to incorporate dynamics and state costs that maximize the distance from a ...
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Moisture sensor for Mixers
I'm looking for alternatives to measure the moisture content in a concrete mixer machine. The ones on the market are expensive, like Hidro-Mix for apparent reasons; mixers are a hostile environment ...
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Meaning of energy method in control theory
What qualifies a energy method in the context of control theory?
Citing from a paper to give the context in which this expression came to my attention:
One of the challenging problems of the double ...
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What is the connection between PID and feedforward controllers?
They are tightly connected as some concepts of feedforward is based on PID algorithms, and both of them are control systems. But when I see a phrase such as "Feed forwards augment PID control", I'm ...
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How to control an underactuated platform with a single servo
What's the best way to control the following type of platform so that it remains balanced and upright?
It's a box supported by a single leg that can pivot at the foot (F) and at the hip (H). The foot ...
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Boundary Conditions for a circular clamped plate
I've been trying to find the boundary conditions for a fourth order DE equation for a bending circular plate. I'm assuming angular symmetry and an even pressure distribution.
Displacement Equation
$$...
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LQR vs. Numerical Optimal Control
I'm a little confused by the differences between LQR control and numerical optimal control (such as direct multiple shooting, direct collocation and pseudospectral optimal control). It seems that LQR ...
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Angular Velocity of motor shaft as function of Angular Position
I have a set of shafts that need to be rotated at a high frequency (~1000 RPM) but not at a constant speed. That is to say, the angular velocity of the shaft needs to be a periodic function of the ...
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Placement of a refractory wall excess temperature sensor?
I am working on a burner management system for a gas/coal fired pulp dryer. We are providing a thermocouple temperature switch on the roof of the firebox for an Excess Temperature Limit Interlock (per ...
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calculate output $y(t)$ from $Y(z)$ having discrete closed loop model with sine input - residue method
I have closed loop - discrete model. This is how it looks in matlab:
I need to compute analitically output $y(t)$ (same as in the Matlab's scope) having $Y(z)$.
Where
$Y(z)=U(z)*G(z)$
Input is sine ...
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Sliding Mode Control
I was going through some literature in power electronics relating to sliding mode control. I noticed that they have separately dealt with the reaching condition and then the existence condition for ...
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Decission between several position switches and one continuos position signal for controling rotating conveyor
We plan a conveyor that will dump something into containers. A level gauge on the tip of the container will measure the heap below. The conveyor is placed on a turntable and will e rotated ...
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Multi variable control of BLDC motor (Speed & DC Link Current)
I am working on a Field Oriented Control ("FOC") based Brushless DC ("BLDC") Motor Controller. The controller takes speed as an input, I need to extend the control system to also ...
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How to design the control loop to synchronize two rotational objects?
There is a rotating object (object A) that rotates at about 50 rpm. Its rotational speed may change slowly. I need to control another object B via a variable frequency motor, so that the objects' ...
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What are typical manufacturing error rates?
In the manufacture of metal pieces which require at least moderate precision (say, ball bearings, or valves, but not roofing nails or door hinges), what is a typical error rate? I only need an order ...
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Why does a lead compensator with little phase contribution reduce the overshoot of the system so dramatically
I am currently designing a lead compensator to allow the following system to conform to some specific requirements: $$ G(s)=\frac{2}{s(s+2)(s+5)} $$
When using the angle criteria to meet these ...
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Obtaining the open loop gain - (estiamte the gain and phase frequency response)
This post is related to the following stackexchange link but in this new question, I am focusing on describing the controller and going over my process of obtaining the open loop vs closed loop gain: ...
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Should codes on instruments represent the quantity they measure or the quantity they regulate (P&ID)
Let say you want to make a P&ID diagram of a process in which a level sensor transmits its data to a flow controller. The quantity measured is a tank's level, but the quantity controlled is the ...
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How often is discrete-time control used in industry?
Although in reality I know that computers handle all systems in discrete time, in my limited industry work experience I've only used continuous-time control system analysis/standard frequency domain ...
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Internal Stability and Small Gain Theorem
I am currently working on a MIMO feedback system and trying to determine its internal stability. The open loop gain of the system is stable and has no internal right half-plane pole-zero cancellations....
