# Questions tagged [geometry]

The tag has no usage guidance.

29 questions
Filter by
Sorted by
Tagged with
1answer
19 views

### Explanation of the epipolar constraint in stereo imaging

I am watching this video, in which the epipolar constraint is defined as $x_l \cdot (x_l \times t)=0$ It means that the vector $x_l$ that passes through the observed point and the left camera origin ...
1answer
33 views

### How to find mathematical model of a wheeled robot (to compute robot's trajectory at given time steps) including its kinematic

I would like to learn, how to find proper kinematic model of robot in mathematical form. For example: I would like to create a model of a car, from which I could compute its position and rotation at ...
2answers
99 views

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

I’m building a drawbot with a self imposed constraint that it’s method of motion is just two rotating disks. One holding the paper and one holding the pen. However, the math to calculate the right ...
1answer
47 views

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

Say we have an object (e.g., end-effector of a robot) that is defined in a general coordinate system by a Cartesian position and Quaternion. since the Quaternion is with respect to a general and fixed ...
2answers
57 views

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

In my robotics textbook 1 , the configuration space has been defined configuration space the following way: A configuration space is a metric space compromising of all given configuration of a ...
1answer
116 views

### Bearing landmark localization

I am trying to initialize the position of a set of landmarks using only bearing observations. Each robot pose, described by position (x,y) and orientation (theta), observes a small set of landmarks. ...
1answer
60 views

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

given position and orientation of two coordinate frames, how can transfer a vector from one frame to another. The position is given in Cartesian space and the orientations in quaternion or Euler ...
0answers
60 views

### How to calculate twist and wrench in local and global frames

I am rather new to screw theory and also lost in robotics books' formulas. we have a simulator of a robot arm within Mujoco physics engine and I'm wondering how I can calculate wrench and twist in the ...
1answer
188 views

### relationship between geometric twist jacobian and wrench

I read the robot textbook of Peter Corke and Richard M. Murray, in Peter’s, chapter 8 about jacobian, there are two jacobian, one is geometric jacobian $^0J$ from math, other is world coordinate frame ...
1answer
105 views

0answers
44 views

### How to determine the angles between a UAV and a sphere

I have an UAV modeled in three dimensions with let's say position coordinates $p_{uav} = (x_1,y_1,z_1)$ that is moving in a direction $d = (d_x,d_y,d_z)$ and a moving obstacle modeled as a sphere with ...
4answers
2k views

### Most accurate rotation representation for small angles

Assume that I have a rigid body for which I know that it can rotate with respect to a global reference frame (which is considered fixed and already given) for only a few degrees of angle, so I can ...
2answers
202 views

### Angle to a circle tangent line

I want to simulate the detection of a moving object by a unicycle type robot. The robot is modelled with position (x,y) and direction theta as the three states. The obstacle is represented as a circle ...
1answer
39 views

### Which geo-projection to use for odometry [closed]

I would like to make a little survey regarding the (geo)spatial projection that you use when elaborating your GPS and movement data for the spatial awareness of your robots. Moving all GPS ...
1answer
107 views

### 6D localization with 6 lasers

I have to know where a multi-rotor is, in a rectangular room, via 6 lasers, 2 on each axis. The problem is like this: Inputs : Room : square => 10 meters by 10 meters 6 positions of the lasers : ...
1answer
190 views

### Relative orientation of two robots

Given two robot arms with TCP (Tool Center Point) coordinates in the world frame is: $X_1 = [1, 1, 1, \pi/2, \pi/2, -\pi/2]$ and $X_2 = [2, 1, 1, 0, -\pi/2, 0]$ The base of the robots is at: \$...