Questions tagged [transforms]
The transforms tag has no usage guidance.
14
questions
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18 views
Defining static transform publisher in launch file
I'm trying to include to my main launch file settings to start my depth camera with pointcloud.
It's launching the pointcloud OK, but I need to set a transform between the base link and my ...
0
votes
1answer
10 views
doubt regarding the base_local_planner::transformGlobalPlan() function
I am trying to understand the base_local_planner::transformGlobalPlan() function.
As per my understanding, the function takes in the global_plan (generated by the <...
0
votes
1answer
16 views
Significance of fixed_frame parameter in lookupTransform function
I was going through the implementation of the lookupTransform function defined inside the base_local_planner::getGoalPose() function.
What is the significance of ...
0
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1answer
24 views
Transform Velocity data from sensor frame to world frame
I am new to Robotics and transformation topics. I need help in understanding and solving the below problem.
I have data (surrounding obstacle position, orientation and velocity) which are in sensor ...
0
votes
1answer
60 views
How to make two frames relative to each other
I have a Velodyne and camera that both have transformations specified relative to the origin of the robot.
The original transformations were specified as yaw, roll, pitch, x, y, z. I wrote a script to ...
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0answers
29 views
Finding orientation of object in 3D space
Given the above constellation, I have to find the orientation of object B in the coordinate system of Object C. The objects A and B are fixed to a certain place and the object C can move in freely in ...
0
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1answer
15 views
Determining Base Configuration Tsb from End-Effector Configuration Tse for youbot
Hello there, hope you are doing great.
Right now I am trying to control youbot to pick and cube and place it to a certain position, on simulation. However, I believe that the reference trajectory is ...
1
vote
0answers
12 views
Getting the new heading after a Transformation
Lets say I have 2d poses as such (angles in degrees):
world_to_robot = {0, 4, 45} robot_to_object = {4, -4, -45}
From a graph it would be easy to see that:
world_to_object = {4, 8, theta}, what goes ...
2
votes
2answers
60 views
Compute path in absolute frame from sequence of measurements
I have a sequence of measurements $\{(x_i, y_i, \theta_i)\}_{i = 1 \:...\: N}$. Each of these represents the new pose of the robot seen from the previous pose, i.e. a measurement $(x', y', \theta')$ ...
0
votes
1answer
38 views
Motion model and homogeneous transformation issue on a drone
I am trying to develop a EKF-SLAM algorithm for a drone, and I want to estimate its position in the inertial/world reference frame. I have as control variables the linear and angular velocities in the ...
1
vote
2answers
69 views
Understanding Twists as 3D Velocities
I am just learning about twists to represent 3D velocities (e.g. of a robot's end-effector), and I have two questions:
1) Wikipedia defines a twist as "an angular velocity around an axis and a linear ...
0
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1answer
258 views
How to calculate rotation angle from 3D points
I have 4 3d points(x, y, z). Using these points how can I calculate rotation angle? Consequently, I want to have a 4x4 transformation matrix including rotation and translation information.
4 points ...
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1answer
50 views
Reference frame, vector
How do I specify the directions of a unit vector $X_n$ and $Y_n$ of a frame $\{n\}$ at an angle $θ$ relative to a frame $\{a\}$ in the form
$$
X_n=cosθX_a + sinθY_a
$$
$$
Y_n=-sinθX_a+cosθY_a
$$
? Can ...
1
vote
1answer
49 views
Absolute 2D pose from previous pose and measurement
I have a pose $\boldsymbol{x}_0 = (x, y, \theta)$ in an absolute frame, right-handed and centered in (0, 0, 0). I obtain a measurement $\boldsymbol{m} = (\Delta x, \Delta y, \Delta \theta)$ in the ...
