5
votes
Accepted
Cartesian Impedance control Damping Design (Double Diagonalization)
A hint towards what the answer is given in the paper. Namely, one can use the generalized eigenvalue decomposition, which in this case can be formulated as finding eigenvalues $\lambda \in \mathbb{R}$ ...
- 941
3
votes
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Why Does an Exponential Make ANYTHING a Probability Distribution
I believe it's because you're essentially constructing an exponential distribution which has the form
Because your loss function will always be >= 0, you form a valid PDF (valid in that it ...
- 191
3
votes
Accepted
Difference between Degrees of Freedom (DOF) and Degrees of Motion (DOM)
The way you are describing it, DOM is the number of independent dimensions in $\vec q$. DOF is the number of independent dimensions in $\vec x$. In practice, a robotics engineer will use DOF to ...
- 4,386
3
votes
Does a controlling system need to be more complex than the system being controlled?
Complexity is not a word that's used in control theory but I think I know what you mean. The short answer would be no.
Complexity in systems to be controlled is usually looked at in terms of how many ...
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2
votes
What algorithm should I implement to program a room cleaning robot?
I'm not sure if you still need it, but for those who happened to google for this thread, I have made one simple version of the algorithm.
Basically, it tries to build the map of the area while it ...
- 21
2
votes
Accepted
What is exact model of haptic interface system in the paper "Time-Domain Passivity Control of Haptic Interfaces"?
It's usually best to contact the author directly if you have a specific question about a specific paper.
The simulations are there only to illustrate the principal of the passivity observer and ...
- 4,385
2
votes
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Is Fuzzy logic applicable for robotics research
I would like to mention that Fuzzy logic is still an active control system used in many industry applications.
In garbage fired power plants, concrete aggregate firing, hydraulics, and the control ...
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Is Fuzzy logic applicable for robotics research
Short answer: Fuzzy logic (FL) isn't applicable for robotics research, The long answer is, that in the 1980s as part of the fifth computer generation fuzzy logic was researched in Japan with the ...
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Is Fuzzy logic applicable for robotics research
Fuzzy logic is definitely used in many of the control systems including but not limited to robotics. See this paper for an example:
https://pdfs.semanticscholar.org/b9a7/...
2
votes
Accepted
Angular velocity in terms of quaternions
A definition of the cross product for quaternions is $$p \times q = \frac{1}{2}(pq - qp)$$
We also have the identity (3.167) in Jazar $$pq = -p \cdot q + p \times q$$
Apparently the vectors $ \dot{...
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2
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Why Does an Exponential Make ANYTHING a Probability Distribution
To complement what Octopuscabbage correctly reported, there exists a strong theoretical foundation for using normal probability distributions in many different contexts, which builds on the Central ...
- 3,995
2
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What is difference between RoboEarth and KnowRob?
RoboEarth was the name of a European project. Knowrob is software that was developed, in part, by the RoboEarth project.
- 4,385
1
vote
Modelling/Theory for Quadraped Robot Leg Example
Most tutorials about kinematics and dynamics would teach you open-chain systems, like the typical robotic manipulator. While in this robot, the leg itself is a closed-chain system, which is quite ...
- 21
1
vote
Accepted
Park and Lynch $F = ma$ derivation for a single rigid body
The key thing to remember is that none of the equations used in the Modern Robotics textbook use "body-fixed frames". The {b} frame is defined as a "body frame" which is ...
1
vote
Hi everybody! I would appreciate some help with this DH convention application. It involves a slider-crank mechanism and I'm not sure I did it right
There's a lot going on here, and it's not specific what your question is as jsotola mentions.
First, you are putting the output of a solve function into ...
- 16k
1
vote
Accepted
Going from Spline to Differential Drive Command
If you have the path you want the robot to stay on, it sounds like you need Pure Pursuit. In this simple algorithm, you steer the robot to some look-ahead point on the path. The gist of it is ...
Ben♦
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1
vote
Accepted
How is this torque value arrived?
I haven't seen the degree symbol $^{\circ}$ to denote a percentage, but both percentages on your drawing result in the same torque: 54.7, not 57. (10.12/0.185) $\approx$ (34.12/0.6238) $\approx$ 54.7.
...
- 16k
1
vote
Articulated configuration
Seems that the book has an error. You are right, they should correct that.
In the drawing it can be seen that those two z-axis are indeed parallel. I recommend that you considered them parallel and ...
- 497
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Is Fuzzy logic applicable for robotics research
I have not seen any industry-grade application of fuzzy logic in space, flight, automotive control systems. Fuzzy logic came during mid-60s and it gradually faded away due to several reasons:
It did ...
- 367
1
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Strange phase case in Bode diagram of a transfer function
It's just a phase unwrapping case in MATLAB. Anyway when real parts of complex poles/zeros are null, phase jump could be +180 or -180, it's uknown therefore both diagrams are correct
1
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How many stages necessary to stabilize position while controlling torque?
If you are trying to implement torque control, you only need a control loop around torque. The challenge isn't in trying to integrate the torque (or acceleration) controller, and passing it to a ...
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How many stages necessary to stabilize position while controlling torque?
I would say the transferfunction becomes $\frac{1}{s^2}$ iff you assume you have a perfect drive without any dynamics.
Since this system is unstable you have to be careful choosing your controllers. ...
- 189
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vote
Why ODE for optimal control theory?
Appending to @WalterJ's answer.
Linear and nonlinear systems which form the basis for subjects like optimal control theory have rigorous math fundamentals which allow you to analyze ODEs without ...
1
vote
Accepted
Why ODE for optimal control theory?
The reason why ODE's are used is simply: physics. It would be great if any system could be modelled by a simple linear function like $x(t)=at$, but nature is not so simple, or linear. Even when you ...
- 156
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Does a controlling system need to be more complex than the system being controlled?
Approaching your question in a broader perspective... I believe that a good answer to it could be provided by Ashby's Law of Requisite Variety - postulated as follows:
When the variety or complexity ...
1
vote
Papers on Algorithms in Robotics
You might like the algorithms run on PR-2 robot. Two papers I can think of are "A single planner for a composite task of approaching, opening and navigating through non-spring and spring-loaded doors" ...
- 11
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What algorithm should I implement to program a room cleaning robot?
Looking at the simpler problem that you were asked - a rectangular room, with no obstacles and clean every part at least once.
The solution is to find a corner of the room, and finding a corner won't ...
- 21
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