Questions tagged [pid]
Proportional Integral Derivative Controller. A type of control algorithm used in many control situations, especially servo systems.
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Multiple PIDs in quadcopter
I am wondering what the use is of two PID loops to control a quadcopter. One PID for stability control and another PID for rate control.
Why can't you just use one PID per axis to control a ...
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2 wheeled, 2 motor robot control
I decided to work on a 2 wheeled robot position mapping problem. For that I have 2 DC motors with encoders from pololu.
I have the following two questions:
Do I need to know the model of each motor ...
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How do you design Quadcopter PID algorithm?
Just to give a bit a context, here are the equations I'm using for the Angular accelerations.
φ** =(1/Jx)τφ
and
θ** =(1/Jy)τθ
So my plant gains would be
φ**/τφ =(1/Jx) along x axis
and
θ**/τθ =...
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Quadcopter multiple ESC angles glitch
I'm developing my fligth controller board on Tiva Launchpad for quadcoper and while calibrating PID I discovered an unexpected behaviour: sometimes quadcopter seems to experience random angle errors. ...
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Comparing LQR and PID controllers for inverted pendulum problem
As far as i can tell, both LQR and PID controllers can both be applied to the cart-pole (inverted pendulum) problem. What are the pros/cons to using one controller over the other for this particular ...
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Dealing with position inaccuracy and latency in PID Loop
Background:
I am new to PID, for my first PID project I am using a simple P-Loop and 300 degree linear potentiometers for position feedback. I am using the roboclaw 2x60A motor controller. The motor ...
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How to program parallel PID control loops? So I can give my robot multiple set points to follow
So I'm in the process of building my robot and it has encoders on every wheel measuring speed and position and a compass sensor measuring heading.
I have 3 seperate PID loops at the moment, I can ...
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The aerial refueling problem: sketch of a feedback controller
At first happy new 2015!!!
I'm looking for my next simulator development: a Tanker is flying at constant speed (350 Knots) (no acceleration, no change of altitude or direction). The Tanker is ...
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The algorithm for the following analog controller => digital controller?
I have found a continous control in the following form:
$$
u(s) = \left( K_{p} + \frac{K_{i}}{s} + K_{d} \frac{N}{1 + \frac{N}{s}} \right)e(s)
$$
but since I need it to "convert" in a digital ...
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PID for Quadcopters
As already mentioned the PID output values that correspond to the error from the desirable error and current error has no units. Let's say we are using only the proportional part of the PID. Is it ...
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How to find a solution for quadcopter PID control
I've built a quadcopter and a rig to safely test it on. I'm working on the PID for controlling the roll pitch and yaw. I understand how a PID works on a more simple plant like say a robot with wheels ...
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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 ...
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Implementing a position control for UAV through a flight controller. Plant model is unknown
We are using Naza-M-Lite for our flight controller without GPS. The localization is obtained through our RGB-D camera sensor. We are able to teleoperate and even implement PID controllers for Roll, ...
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Is the input of ESC really limited at 50 Hz and will the PID controllers work properly?
Based on the wiki page of ESC, the ESC generally accepts a nominal 50 Hz PWM servo input signal whose pulse width varies from 1 ms to 2 ms
http://en.wikipedia.org/wiki/Electronic_speed_control
For ...
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RNN instead of a PID controller
I am building a drone using the raspberry pi and I am using 6*PID controllers to control the speed and the value for each angle, can I use a recurrent neural network (RNN) or other neural network to ...
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PID Control Tuning [duplicate]
Im currently designing a robot for my undergraduate project. One of the task of this robot is to follow the wall. For the purpose I'm using a PID control system, where the reference is given from a ...
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A general question about PID Controller
I have a basic question because I'm trying to understand right now a concept that I thought it was obvious.
Looking at this video he is going to feedback the variable state x with the input of the ...
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Position Controller for a Quadrotor
I have a question regarding the implementation of a quadrotor's position controller.
In my Matlab model the quadrotor takes 4 inputs: a desired altitude ($Z_{des}$) and desired attitude angles($\Phi_{...
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Deducing single wing plane transfer function Aka Transfer function estimation through set of points
I'm trying to control a plane via roll using PID controller ,
I had a problem finding the transfer function thus I used the following method :-
Fix the plane in an air tunnel
change the ...
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What is a PID as is related to quadcopters [duplicate]
I'm trying to make a Quadcopter from scratch, I have a fair amount of experience with adruinos, and I'm trying to understand how to necessary systems work, and I can't seem to figure out what PID ...
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Yaw angle calculation for drone PID from two distance sensors
I'm building a control system with a Parrot AR 2.0 drone where I have access to thrust controls for up/down (z), left/right (y), forward/backwards (x), turn left and turn right (yaw) through a Ruby ...
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PID Tuning Quadcopter Problem
I am tuning PID for quadcopter, the problem i have is that with different base Throttle, i seems that i have to adjust different PID gains in order for the quadcopter to balance!
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PID in a system with pole at origin
I've seen in a lot of places some methods of tuning a PID controller. Most of them will say that one should apply a step input to the system and based on that response you can tune the PID parameters ...
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Gains optimization package?
Hi all,
I am looking for a package allowing to optimize gains for a given robot (or a simulated robot) - such as low-level PID gains. The idea is to provide init gains to the package and a cost ...
arennuit
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Natural frequency computation (for PID gains computations)
I am currently trying to parametrize the low-level gains of a robotic arm. This arm uses a classical PID for each joint.
I am trying to use a method based on computation rather than a trial-and-error/...
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Position Control of an Omni Wheel Drive Robot
I want to create a robot that will navigate on a desired path!
That path can be a straight line or a circular path with a given radius.
I will use 3 or 4 omni wheel drive platform and for positioning,...
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Cascading PID DC Motor Position & Velocity Controllers
I'm trying to build a robot with a differential drive powered by two DC Motors. First I implemented a PID Controller to control the velocity of each motor independently. Estimated the TF using the ...
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PID Integration over not constant dt (∆time)
Is integration over not constant dt (∆time) a possible thing? Let's say you have a PID loop with differentiating frequency, can the integral part of it still work? (Assuming you know the dt from the ...
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Good method for Retuning a PID After Detecting Oscillation
Given a PID controller with an anti-windup, what are some practical ways to retune the controller once oscillation has been caused and detected? I have access to the magnitude and period of the ...
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Electronic Speed Control Concepts
I am a programmer who has never worked with electronics before. I am learning the concepts and hoping to build a quadcopter, with the control software entirely written by me. Motor control seems to be ...
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Controlling a system with PID that resists backdrive
I'm controlling the angular position of a pendulum using a DC motor with a worm gearbox. Mechanically, worm gears are impossible to backdrive.
Using a PID controller on a pendulum system with a ...
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Velocity Control via Vibration
I am working on a robot that has an accelerometer. This accelerometer measures the vibration of the robot. When the robot hits a certain vibration, I would like it to slow down in order to reduce the ...
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How to use quaternions to feed a PID quadcopter stabilization loop?
I'm making a quadcopter. I have set up a PID loop to stabilize it to a given Euler angle (pitch and roll). The problem arises when the roll approaches 90 degrees (45 degrees and up). The values don't ...
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PWM PID control for small 2 watts brushed DC motor
It is "good enough" for PID output directly controls, without further modelling, the PWM duty cycle?
Logic behind the question is,
In case of pure resistance heater, PWM duty cycle percentage ...
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Are there any problems with a variable frequency PID?
I am working on a quadrotor and am trying to solve the problems described here. In attempts to bring the refresh rate to 100 Hz, I did an analysis of the functions and most of the time 35+ ms is ...
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How frequently should a PID controller update?
I am developing a quadcopter platform on which will be extended over the next year. The project can be found on Github. Currently, we are using an Arduino Uno R3 as the flight management module.
At ...
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Quadcopter PID output
I'm trying to develop a control system to a quadcopter and one of my options is to use a PID controller (which I think is the most used method).
From what I've read, the commom strategy is to run a ...
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PID tuning method based on Pole placement
Is it possible to determine PID parameter using pole placement.
I mean by solving the ch. eq. of close loop transfer functions which consists of either P,PI,PD or PID controllers??
Because i've ...
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What does this "inverse" peak mean? (step function)
I identified my system and now I am trying to tune PI regulator since I think I do not need D.
I came across this graph while Matlabing and I do not know what does it mean.
I am using pidtune() to ...
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Quad copter attitude control
I have built a quad copter completely from scratch (electronics, mechanics and software).
I am now at the point where all my sensor data looks correct and when I tilt the quad copter the correct ...
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understanding the PID controller
I am trying to understand the effects of P, I and D constants in a PID controller on a system.
As far I've understood, P and I make the system 'faster', and D makes it 'slower'(which I read in books),...
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How do i use the Nicolas ziegel approach if my system never becomes unstable?
How do i use the Nicolas Ziegel approach when the root locus plot of my system never becomes marginally stable , for any gain (unless it is negative).. ??
How do i estimate my ultimate gain value????
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Effect of adding a Pole and Zero to PID
I am confused about how adding a D (which adds a zero to the complete system) decreases the speed of the system. But when we normally add a zero to the system, it causes the system to overshoot.
The ...
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Differential Drive Robot Control
Edited: I have a differential drive robot that needs to drive down a hall and stay in the center. I have 4 ultra sonic sensors, 2 on each side. Currently, I thought of implementing pure pursuit and ...
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What kind of motor control can I implement if I cannot use an Encoder?
Every time I see a PID control for a motor, it involves an Encoder, so the algorithm knows the real position of the motor or wheel.
But with the robot I have, I cannot use an encoder. I only have ONE ...
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Differential Drive Robot on uneven surfaces
So I am building a differential drive robot and I want it to autonomously drive in a straight line on an uneven surface. I know I need a position and velocity PID. As of now, I am deciding on which ...
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PID output does not reach setpoint precisely enough
I'm developing/tuning a software PID for a quadcopter. For now I'm only trying to stabilise the pitch angle using the front and back motors, and I'm only looking at Kp. The motors have a control ...
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Quadcopter Throttle and PID mixing to Motor Speed
I've been writing some quad copter software and I am not sure what the best way is to map the throttle and PID inputs to ESC power.
My throttle range is 0-1 and my PID outputs are 0-1. My ESC's have ...
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