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4 votes
Accepted

How can I draw a line using rotation of two circles?

Made a quick diagram and a couple of calculations in matlab, let me know if it works for you. First of all, I am assuming you are considering your piece of paper as your reference coordinate system (...
Victor Jaramillo's user avatar
3 votes
Accepted

Mobile robot algorithm implementation error

So I'll point out what might be some problems, at-a-glance, but wow this is one of the longest questions I've seen here. I'm pretty swamped with real-life stuff at the moment, so I'll just point these ...
Chuck's user avatar
  • 16k
3 votes

given position and orientation of two coordinate frames, how to transfer a vector from one to another

A homogeneous transform $T$ is 4x4 matrix that looks like: $$T=\begin{bmatrix} R & t \\ 0_3 & 1 \end{bmatrix}$$ where $R$ is a 3x3 rotation matrix and $t$ is the translation. The rotation ...
edwinem's user avatar
  • 1,891
3 votes

Representation of 2D coordinate space with orientation

You need to resort to the Special Euclidean groups. In particular, in your planar case, the group is $SE\left(2\right)$ and thus the representation is the following: $ T=\left(\begin{matrix} R & ...
Ugo Pattacini's user avatar
2 votes

Fence avoidance for manually controlled robot

I think that your problem is rather uncommon, so there may be no solutions ready to use without any modifications. However, you may have a look at "The Dynamic Window Approach to Collision Avoidance" ...
mactro's user avatar
  • 953
2 votes

Do I need to use Inverse Kinematics if I have the coordinates of all joints?

People use complex inverse kinematics because they do not have the joint positions. In the case of an industrial robto, you know the you want the end effector at a certain position, and you calculate (...
50k4's user avatar
  • 6,682
2 votes
Accepted

relationship between geometric twist jacobian and wrench

I'd suggest thinking about the problem this way: When you construct a Jacobian for an arm, it will typically map your joint velocities to to one of three representations of the end effector velocity: ...
RLH's user avatar
  • 619
1 vote

How can I construct a semi-circle in urdf

Cylinders are easy because they are one of the core primatives supported by URDF: https://wiki.ros.org/urdf/XML/link box cylinder sphere If you want to use a geometry that doesn't consist of one of ...
Tully's user avatar
  • 25.1k
1 vote

Explanation of the epipolar constraint in stereo imaging

Doesn't it hold for ANY two vectors v and w that v⋅(v×w)=0? -> Yes but you should think about the later part of the lecture where this obvious equation is converted into an essential matrix ...
Chanoh Park's user avatar
  • 1,577
1 vote
Accepted

Finding orientation angles of end-effector from the DH parameter table and transformation matrices

Your $A_{0.3}$ matrix is a 4x4 transformation matrix. In a general form these 4x4 matrices can be subdivided into a 3x3 rotation and a 3x1 translation part. (The remaining parts can be used for ...
50k4's user avatar
  • 6,682
1 vote

given current position and Quaternion and target local rotations (α, β, γ, in radians), how to calculate the new Quaternion

It is often useful to create a 2D example and use rigid-body transforms (i.e., $T\in\text{SE}(2)$, where ${\small T=\begin{bmatrix}R&t\\0&1\end{bmatrix}}$, $R\in\text{SO}(2),t\in\mathbb{R}^2$)....
Parker Lusk's user avatar
1 vote

What is the idea behind calling configuration space a metric space?

I did not read the book. But one of possible thinks that came to my mind is this: There is big field in mathematica dedicated to preciselly define some terms (set, metric, metric space, ...) and prove ...
gilhad's user avatar
  • 453
1 vote
Accepted

Bearing landmark localization

So the method to figure of something with only bearing measurements is called triangulation. While I think your method works you can much more easily solve it using sin rule. Given at least 1 side ...
edwinem's user avatar
  • 1,891
1 vote

Efficient sphere surface area search

I suppose this is a question of what is "most efficient" and what are you actually doing? And how are you going about simulating it? Are you looking for a mathematical proof of how to find all ...
DrMrstheMonarch's user avatar
1 vote

Generalized Voronoi Diagram

The project repositories at Florida State should get you what you are looking for: https://people.sc.fsu.edu/~jburkardt/m_src/m_src.html Look at not only the projects which start with "voronoi_," ...
SteveO's user avatar
  • 4,396
1 vote

Vısual sensor.camera lenses with a field of view of more than 180 degree

Simple fisheye lens model will cover angles over 180 degrees. Fisheye lens model maps the incident angles into x,y coordinate on the image using a polynomial function. Thus, whatever the fov is, it ...
Chanoh Park's user avatar
  • 1,577
1 vote

Vısual sensor.camera lenses with a field of view of more than 180 degree

Consider the alternate approach of using a parabolic mirror. The advantage clearly bing cost and possibly operating under lower light conditions. The disadvantages include more distortion, seeing the ...
st2000's user avatar
  • 506
1 vote

Image coordinate to robot coordinate

The standard way to perform projection transforms between camera images and the world outside is through a projection matrix. Look at this presentation starting at page 25 for an introduction to the ...
xperroni's user avatar
  • 1,363
1 vote
Accepted

Recognizing a line from three r-theta ultrasonic distance readings?

Checking for three is a subset of checking for many; so, I am going to consider the more general solution. I will discuss the three point solution at the end. First, convert the polar coordinates to ...
markshancock's user avatar
1 vote

6 axis robot arm with non-perpendicular axes?

The sketch seems to represent a Kuka KR60-HA, doesn't it? First of all, one might ask oneself, why, for instance, the rotation axis of joints 4 and 6 is the same. My ad-hoc answer would be that Kuka ...
sirop's user avatar
  • 51

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