Unanswered Questions
3,572 questions with no upvoted or accepted answers
7
votes
2
answers
672
views
Reward Function for q learning on a robot
I have 2 wheeled differential drive robot which I use pid for low level control to follow line. I implemented q learning which uses samples for 16 iterations then uses them to decide the best position ...
CommunityBot
- 1
6
votes
0
answers
429
views
Likelihood field sensor model (Probabilistic Robotics, Thrun et al., p.169-174)
I am currently working on the "likelihood field" sensor model (aka "endpoint model") by Thrun et al. (book: Probabilistic Robotics, Thrun et al., p.169-174)
In this context I have ...
Ben♦
- 5,885
5
votes
2
answers
404
views
Inferring joint orientation on multi-joint arm
Not a robotics question in the strictest sense, I guess, but related closely enough, I hope:
I have an arm-like articulated two(-plus-one)-joint appliance that I want to use as a 3D input device. It ...
CommunityBot
- 1
4
votes
0
answers
659
views
How to fuse IMU with encoders in EKF
Background
I have a car-like mobile robot (4 wheels, where the forward ones are steering wheels) and I want to estimate its pose and velocity assuming 2D planar motion. I'm trying to solve this ...
- 1,657
4
votes
1
answer
362
views
Motion planning with Gaussian Process Regression
I was recently introduced to Gaussian Process Regression (GPR). I read multiple papers regarding use cases of GPR in robotics, however, they were more or less very limited.
Use case from the ...
CommunityBot
- 1
4
votes
0
answers
492
views
How does marginalization of variables effect least squares SLAM energy function?
Consider a simple example of Bundle Adjustment where I have robot and landmark poses $x = \left[ x_p \text{ } x_m\right]^T$ and measurements given by $z$, such that a simple factor graph can be ...
- 163
4
votes
0
answers
595
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How does one implement a third order complementary filter for estimating altitude using data from an accelerometer and a barometer?
I am working with the CJMCU build of cleanflight on a small drone. As of now, the algorithm for altitude hold uses a first order complementary filter to combine data from the barometer and the ...
- 101
3
votes
0
answers
46
views
How to monitor sensor reliability in ROS2?
I'm building a mobile robot with multiple standard sensors (camera, imu, etc.) and have a general question about how to monitor the sensors' reliability.
More specifically, I am using a camera along ...
- 31
3
votes
1
answer
89
views
Build with colcon only up to packages in a given directory?
I have a workspace with multiple repositories checked out, and each repository contains many ROS 2 packages. The packages in a repository can depend on packages in the other two repositories.
For ...
CommunityBot
- 1
3
votes
0
answers
73
views
RViz2 Text Markers Spacing Issue
I am trying to publish a Text Marker to RViz2 (ROS2 Humble). No matter which settings I choose, the text markers always seem to have inappropriate spacing (usually too big).
See image below. Notice ...
- 31
3
votes
0
answers
267
views
Extern Controller, Cannot connect to Webots instance
I installed ROS2 on WSL2, Ubuntu22.04, and follow the tutorial in this link, which helped me install webots on Win11.
But when I execute this command ...
3
votes
0
answers
34
views
How to calibrate IMU for large scale deployments possibly using deep neural network
We were testing our visual SLAM algorithm on robots. We were getting poor performance. Then we calculated wite noise and random walk parameters (using kalibr) for the IMU and used it in our algorithm ...
- 151
3
votes
1
answer
3k
views
PointCloud2 parse to xyz array in ROS2 with python
In ROS1 you can convert a pointCloud2 message to an xyz array with sensor_msgs.point_cloud2.read_points().
Unfortunately, this option has not yet been adapted for ...
CommunityBot
- 1
3
votes
0
answers
344
views
Nonlinear Sensor Fusion with Space-Time Finite Element and Static Condensation?
I have recently implemented an algorithm for the nonlinear fusion of GNSS, barometer, magnetometer, accelerometer and gyroscope data.
The algorithm is based on a space-time finite element where the ...
- 1,657
3
votes
1
answer
130
views
Covariance of Gaussian after sequence of homogeneous transformations
Assume we have a robot that moves and observes landmarks on his path. The path is composed of $k$ poses $s_1 \: ... s_k$ where $s_i = [x,\ y,\ \theta]$. From the sensors, we read the motion ...
CommunityBot
- 1