# Questions tagged [coordinate-system]

The tag has no usage guidance.

37 questions
Filter by
Sorted by
Tagged with
214 views

### Range of a heading angle [0,2π) or [−π,π)

Consider the unicycle dynamics in 2D plane: $$\begin{array}{l} \dot x = v\cos \varphi \\ \dot y = v\sin \varphi \\ \dot \varphi = \omega \end{array}$$ What is the range of the heading angle $\phi$? ...
• 189
76 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 $(x', y', \theta')$ ...
1 vote
543 views

### Conversion of roll, pitch and yaw from ENU to NED

I have roll, pitch and yaw values in an ENU frame. How can I convert it into a NED frame?
1 vote
429 views

### Conveyor Belt Calibration for a Robot - Rotation Matrix

Short Question: As demonstrated in the image below, how can I calculate the rotation matrix that relates the base coordinate and the rectangle coordinate, given 3 known points P1, P2, P3 on the ...
1 vote
19 views

### Which way should angles be measured given a coordinate frame, according to convention? And if going against convention what are the implications?s

Note: My application is not robotics, but purely theoretical. I have been suggested to ask this question on the robotics forum. The results of the project could easily be applied to robotics however ...
1 vote
35 views

### Conversion from body frame to NED frame

I have following Python code: ...
• 121
64 views

### How do you write unit tests for robotics related software?

In my case, I have a library handling 3D input data and want to write tests in order to make sure that my coordinate transform chains for getting the 3D points from A to B are correct. The problem I ...
• 681
205 views

### How do I convert a set of coordinate and rotation values

I'm an electrical engineer who needs to use a robot for their first time. I have a UR5 that I'm controlling through the rtde interface via Python. It seems that what I'm trying to do must be something ...
148 views

### Confusion on TF2 frame name conventions, base_link vs odom?

I was reading about TF2 frame name conventions for mobile robots: https://www.ros.org/reps/rep-0105.html and I'm confused on how base_link and odom frames are related, odom gives the location of the ...
• 393
87 views

### How are these equivalent rotation coordinates related?

I am using a 6 DOF UR5 robotic arm. I am successfully sending it commands in the [X,Y,Z,RX,RY,RZ] format. When I read back these coordinates, I find that the X, Y, Z values are the same but the RX, RY,...
222 views

### How the motor commands are obtained from gcodes?

I have started my research with scara and cartesian robots for drawing robot. The gcodes are converted and given to robot. There are firmware like grbl, marlin, etc for this process. But I couldn't ...
43 views

### Mixing coordinate frames and transformations

Could somebody explain to me the mixing of coordinate frames and transformations with each other in Robot Manipulators: Mathematics, Programming and Control by Richard Paul? On page 102 it says: The \$...
17 views

### How to transform frames so axis align

I have the location of two sensors, S_1 and S_2 with frames attached to each and I have the frame Transformation that gives S_2 location and orientation with respect to S_1. Additionally I have a ...
• 393
22 views

### Camera pose estimation problem

I am creating a Pick and Place program and need help with pose estimation. I am broadcasting on RViz the coordinates based on my YOLO detection and camera. Below is my broadcasting node. ...
32 views

### Producing an X any Y coordinate from a Lidar sensor

The project I am working on needs to track a ball on a 10' by 10' platform. I need to produce coordinates with the 2d lidar sensor I have. The sensor I have available to me is a Sick TIM561. The ...
41 views

### How to use tf for custom rotation

Hi! I am trying to generate the starting points and the ending points of the following arrows: The idea is that I get the start (yellow, 0,0,2) and the end (orange 1, 1, 5). The arrows are the path ...
11 views

### MAVROS coordinate system

Hi, I'm using mavros with PX4 firmware. I wonder that the values of the orientation published (in quaternion format) are in which coordinate system. I'm not meaning NED or ENU but the world coordinate ...
9 views

### Georeferencing map coordinates

I was wondering how ROS handles georeferencing of map coordinates. My robot currently sets its position when it starts up as position 0.0. However this doesn't give any information about where I am in ...
15 views

### tf API: Axes/order of rotation

Hello ROS users! I'm working with tf and I've a few questions about the API. I am defining frames such that Yaw is applied around Z, followed by Pitch around the new Y and then Roll around new X. ...
15 views

### Selecting map/odom frames for GPS/IMU

Hello forum, I am working on a project where I need to combine LIDAR scans and camera images from a drone. An INS mounted on the drone provides GPS and IMU information. I read REP 105 and tf tutorials ...
13 views

### Getting coordinates through comparing .pgm files using opencv

1 - Generated the .pgm files through gmapping using LIDAR data. -- One with partial map -- One with map of the whole area Trying to: 2 - Use opencv to compare the maps 3 - To get the coordinates of ...
25 views

### (Rviz <-> point cloud from pcd) transformation

Hi! I am reading in point clouds from *.pcd-files and am visualizing them using RViz. Unfortunately, the point cloud is weirdly oriented: Look here (the "right" side of the point cloud is ...
43 views

### How to determine yaw angle from GPS bearing?

How can I determine yaw angle if I know bearing angle from GPS? The GPS I have can output bearing, which is the angle direction from point1 (at time1) to point2 (at time2). The bearing I have is equal ...
97 views

### Occupancy Grid Coordinates

Hi, This might be a newbie question but i need a help with it or at least to be pointed in the right direction. I need to extract/acquire the (x, y) coordinates of a given map's (grid) cells to be ...
2 views

### Using TF package to transform rotations

I'm using the Gazebo simulator and gazebo_ros to interface with it. It the simulator, I have a "quadcopter" object. I would like to apply a thrust to the quadcopter. Gazbo_ros offers a way ...
9 views

### Coordinate frames in set_model_state topic with gazebo_ros

I am using ROS Indigo with gazebo 4.0.1 as installed by the ros-indigo-gazebo4-prerelease-* packages. I am trying to use the set_model_state topic to move a Pioneer ...
• 5,602
3 views

### [SOLVED] Getting map co-ordinates

We are building a SLAM map using our Turtlebot. During the process, we stop the Turtlebot at certain points and would like to obtain the x,y,z values from the map coordinate frame. We are using the /...
57 views

### Project point cloud to image coordinates using camerainfo

Hi, I'm new to ROS (and PCL as well) so sorry if the question is too trivial...but I've been searching for quite a long time and couldn't find an answer.. I have the pointcloud and I need to project ...
86 views

### Question regarding Roll Pitch Yaw and coordinate system

Hi all ! I have a question regarding the Roll Pitch Yaw convention in ROS (applying to all the the getRPY and quaternion convertion function). I am aware that the convention in ROS is the fixed XYZ ...
15 views

### Drawing poses in a coordinate system in rviz

Hi, I am developing in a visual SLAM context and would like to draw the resulting camera poses for each keyframe in rviz as coordinate systems(i.e. three arrows), to see how well the localization ...
19 views

### pcl coordinate system orientation

I am aware that ros uses the positive coordinate system in which x=forward, y=left, and z=up, but can anyone tell me what pcl data uses? Originally posted by ee.cornwell on ROS Answers with karma: ...
3 views

### robot_pose_ekf coordinate frame

I have a visual odometry source which outputs Ros odometry msg in a coordinate system of the camera which is z-axis forward. Now i also have an Imu based odometry which gives data according to ...
169 views

### Aligning accelerometer readings with vehicle's frame of reference

I have a device with an accelerometer installed in a vehicle. Its orientation in relation to the vehicle is unknown. So I am looking for a reliable way to align the coordinate system of the ...
84 views

### Find a mistake in transformation between different coordinate frames in the WIP-calibration pipeline

I design the extrinsics calibration pipeline for the robotic agents, carrying onboard two sensors of different modalities. I aim to calibrate one of them (S) ...
• 131
135 views

### How to extract robots coordinates using ICP algo

I would like to know How to extract robots localization from the icp or ndt algo, currently I'm using scan registration for this reason
• 123