Robotics Stack Exchange
Robotics Stack Exchange

Questions tagged [control]

A method or device to manage, command or regulate some part of a system.

enter image description hereControl in the context of robotics may refer to:

  • The functions which allow a servo to maintain its position.
  • The theory or mathematics that govern the control of a robot.
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Optimal Control for a simple pendulum

I'm studying various optimal control methods (and implements them in Matlab), and as test case I choose (for now) a simple pendulum (fixed to the ground), which I want to control to the upper position. I managed to control it using "simple" feedback…
Francesco
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Using genetic algorithm for tuning controllers

I've read some papers for controlling nonlinear systems (e.g. nonlinear pendulum). There are several approaches for targeting nonlinear systems. The most common ones are feedback linearizaing, backstepping, and sliding mode controllers. In my case,…
CroCo
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What's the difference between feedback and feedforward control?

I'm reading from Astrom & Murray (2008)'s Feedback Systems: An introduction for scientists and engineers about the difference between feedback and feedforward. The book states: Feedback is reactive: there must be an error before corrective actions…
Paul
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How much can working with CNC machines teach you about robotics?

I have built a few simple X/Y/Z CNC machines. I've learned about G-Code, motor control, firmware and open loop systems. I see machines like rovers, big dog and factory arms that seem incredibly complex by comparison, yet they don't seem that…
Great Turtle
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Keyboard control map for scalar based movement?

I'm working with a Wild Thumper 6 wheel chasis that is designed for use with an RC controller. However I'd like to have a mapping to a keyboard for control as well. Can you suggest a set of keys and behaviors that you've used to deal with the…
Ian Danforth
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Controlling the Power of a Solenoid

I am trying to control the force of a solenoid. My current system has a bank of capacitors connected to a relay. In order to control the force (how hard I am trying to hit the object) I am increasing or decreasing the the time the relay is on. The…
user2095599
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How to explain bandwidth of a measurement to a noob?

I am working on a system which is measuring a force. The specification is to have a 500Hz bandwidth on the measurement. Now I was trying to explain this 500Hz bandwith to my mom and I could not really explain it easily. What is the most easy way to…
2pietjuh2
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What is the name for the transfer function, GH

What is the name for the transfer function, GH, in a simple feedback control system like $$y=\frac{G}{1+GH}u$$ What do you call G? What about (G/(1+GH))? I am confused by the fact that that "open-loop transfer function" and "Loop transfer function"…
guest
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Use linear quadratic regulator to minimize output error

I would like to create an Infinite-horizon, continuous-time LQR with a cost functional defined as $$J = \int_{0}^\infty \left( e^T Q e + u^T R u \right) dt$$ where e is the states' error $x-x_d$, but I have trouble concluding to the appropriate…
Controller
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how does poles and zeroes affect the step response of an transfer function?

I have this close loop transfer function: It overshoots, but why? The poles are placed such that that the damping = 1, so why the overshoot?
Control
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How PID affect the Root locus of a close loop transfer function

I am trying to understand how a PID controller moves the poles and zeros of an transfer function. I've been playing a bit with it, but aren't able to see some kind of connection. I mean that P and I rises the Overshoot which would mean that the…
Control
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What is meant by a speed profile?

When researching robots, micro mouses etc I've often come across people taking about generating "speed profiles" and how to calculate them. Also profiles for acceleration , deceleration , turning etc. Also trapezoidal profile? But I can't seem to…
binarysmacker
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Visual servoing: simple control law

The problem I have a control scheme like the one in the image attached below (Source: Robotics, Vision and Control Fundamental Algorithms In MATLAB®, Peter Corke). But instead of a robotic arm, I have a pan/tilt head. I am not sure what control law…
Optical_flow_lover
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Use computer to throw a small switch

Would like a product that enables me to use my computer to throw an small DC ON / OFF switch. Seems like a stupidly simple thing to do, but for the life of me I can't seem to find such a device when I search online. Is there a device floating around…
Chris Dutrow
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Input/output linearization

I am studying the book "B. Sicilliano -Robotics. Modelling, Planning and Control" chapter 11, Input/output linearization topic. Where does the formula for theta in 11.75 come from? In the case of the unicycle, consider the following outputs: $ y_1 =…
Leon Rai
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