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Questions tagged [control-theory]

Anything related to control theory, i.e. the branch of systems engineering studying the mathematical techniques used to make a dynamic system behave in some desirable way.

Anything related to control theory, i.e. the branch of systems engineering studying the mathematical techniques used to make a dynamic system behave in some desirable way.

See Wikipedia page on control theory.

78 questions
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PID controller integral term causing extreme instability

I have a PID controller running on a robot that is designed to make the robot steer onto a compass heading. The PID correction is recalculated/applied at a rate of 20Hz. Although the PID controller works well in PD mode (IE, with the integral term…
chris12892
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I don't understand Integral part of PID controller

I dont understand integral part of PID controller. Let's assume this pseudocode from Wikipedia: previous_error = 0 integral = 0 start: error = setpoint - measured_value integral = integral + error*dt derivative = (error - previous_error)/dt …
user561838
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Functional approaches to designing the discrete side of hybrid systems

I'm working on developing controllers for hybrid systems in Haskell. FRP libraries (right now I'm using netwire, but there are several good ones and a lot of interesting research on future ones) provide a great solution for the continuous-time side…
Doug McClean
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Python: Identifying a State Space Model for a System

I am looking to obtain a state space model for a system I have, using python. I have tested the actual system, so I have the inputs to it and I have measured the outputs. so I have sets of corresponding inputs and outputs. Is there a function…
Ahmed J
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Bumpless transfer in FRP

I can build a PID controller in the Haskell FRP library netwire using loop from the ArrowLoop instance provided for Wires. I can also implement switching between controllers or between a controller and a manual input using switch. How can I…
Doug McClean
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Quadcopter PID controller

Context My task is to design and build a velocity PID controller for a micro quadcopter than flies indoors. The room where the quadcopter is flying is equipped with a camera-based high accuracy indoor tracking system that can provide both velocity…
xabre
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Creating a MIMO (multiple input multiple output) transfer function system without hardcoding the number of inputs and outputs

Introduction As part of a larger system I'm trying to create a multiple input multiple output transfer function that only links inputs to outputs on the lead diagonal*. I.e. it has non zero transfer functions between input 1 and output 1, input 2…
Richard Tingle
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PID controller - intuition for when error=0

I have simulated a PID controller with an input parameter that affects the output, and set Kp=0.2, Kp=0.5, Kd=0 which seemed to work best the values I expect in reality. However one thing I could not figure out is the intuition of how the controller…
nickb
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Negative phase margin for stable system

I want to determine the phase margin for the following transfer function: sys_ol = tf([1.225 -1.1 -0.4183 0.3977],[1 -1.36 -0.4119 0.4019 0.9352 -0.565],1) Its a discrete plant with sample time 1. By analysis of the poles I can see that the system…
DayAndNight
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Index of non-number element in Matlab

I have defined an array with transfer functions inside it. How can I find the position of a certain transfer function inside that array? s = tf('s') % defining a transfer function array = [s, s^2, s^3]; >> find(array==s) undefined function 'eq' for…
bergercookie
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Creating an uncertain model based on a family of multiple inputs multiple outputs models (MIMOs)

Objective Currently I am trying to create an uncertain system based on a family of statespace models using ucover. For this I am basing my script on the documentation "Modeling a Family of Responses as an Uncertain System" which shows the technique…
Richard Tingle
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How to simulate a system output with a sine wave input?

I wish to simulate the output of a certain gear system I have. How the gear system looks isn't particularly important to the problem, I managed to get the differential equation needed from the mechanical system. Here is the code I have %…
Marx
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Quadcopter PID Controller for distance

I am trying to use a PID controller to stop a quadcopter at a specific location while travelling horizontally, however currently it overshoots/undershoots depending on the max velocity. I have tried manually tuning the P,I and D gains with limited…
Brien Crean
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define a Linear Time-Delay system in Mathematica and plot it's Bode and Nyquist diagrams

I have a characteristic equation of a time-delay system and i can't define it with StateSpaceModel or TransferFunctionModel command in Mathematica; Because these commands only work for linear systems without delay. My purpose is to define a…
Jalil
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Key difference between PID and LQI integral terms

I am working on control theory implementation on quadcopters. So far I have empirically implemented a PID and an LQI (Linear Quadratic Integral) controllers and tested them. I got a MUCH robust performance from LQI in terms of noise and disturbance…
M.A.
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