6
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Which is a good and cheap 3D LIDAR or other options?
There are now some sub and around ~1000USD 3D Lidars available. I wanted to provide an answer for future reference if anyone else comes looking for "cheap" Lidars.
LeddarTech M16 ~500 USD ...
4
votes
3D mapping using only a 2D Lidar
That is an already solved problem. As Squelsh mentioned CSIRO released its initial version in 2009 and their work is commercialized by GEOSLAM already.
One of a CMU student released a open source ...
- 1,577
4
votes
How does 3D Lidar work?
Lidar, sonar, and radar all work generally the same:
Emit a pulse. For radar, this means briefly energizing an antenna. For sonar, it means briefly energizing a sound transducer/speaker. For lider, ...
- 15.9k
4
votes
Occupancy grid maps
As the wikipedia page of Occupancy grid mapping explains, the result of the mapping process is a binary 1 or 0, occupied or not, the decision itself may be based on noisy data, which involves the ...
- 6,682
4
votes
Accepted
Calculate transform from different poses
I am just going to explain from the basics. So feel free to skip through the first part and scroll to the bottom if you want the answer.
Basics:
The 3 parameters of your pose are $x,y,\theta$.
These ...
- 1,901
4
votes
Accepted
slam_toolbox mapping is not life-long?
They are removed, but it takes some data to do so. We store a set of hit vs misses for each cell in the grid. If you went over it and laser scans saw it in lets say 10 iterations, it would take at ...
- 6,389
4
votes
Accepted
Autonomous Mapping help!
I think there is a bit of misconception with what SLAM does, just remember that SLAM stands for; Simultaneous Localization and Mapping, what you want is to explore the map (autonomously of course) so ...
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3
votes
Accepted
3D mapping using only a 2D Lidar
I don't think what you're asking is possible with the state of the art sadly. You cannot, AFAIK, generate a 3D map from a hand held 2D LIDAR without any other sensors. It's a very interesting question ...
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3
votes
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A sensor that can see glass/transparent objects and surfaces
I'm pretty sure that a very basic IR proximity sensor would do the trick. Glass is opaque to all but visible light. IR (as well as UV) will not penetrate the glass and you ought to be getting reliable ...
- 1,057
3
votes
A sensor that can see glass/transparent objects and surfaces
Unless you need very good resolution or a very tight detection pattern, I would go with an ultrasonic sensor. They can be very cheap and easily meet your detection range specs, for the very low end ...
- 1,914
3
votes
World and Map Frame for a real robot
As you've figured, static transforms are valid for fixed offsets such as sensor positions. They are the minimal solution the more complete recommended solution is to setup a robot model. There's ...
- 25.5k
3
votes
ROS2 Map not received when using nav2_bringup
The nav2 map server is the one that puts the map into the /map topic, the map is published once during launch and not continuously published. If you would like to see the map again you could use the ...
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3
votes
[slam_toolbox]: Failed to compute odom pose
I can see the standard frame in slam_toolbox param file is base_footprint. See yaml-file.
I can't see it in your tf.
- 56
2
votes
How can I implement tremaux algo in arduino line follower to navigate and create map?
I would highly recommend using the encoders over estimating travel distance by rpm + time. Estimating motor velocity is notoriously tricky. Especially at slow speeds.
A direct measurement is ...
Ben♦
- 5,885
2
votes
Accepted
Path of the robot
One of the ways to do path tracking is by indoor mapping. In indoor mapping you can use Triangulation method. Basically, this method uses the help of Relative Received Signal Strength (RSSI) from ...
- 179
2
votes
Accepted
Is SLAM done only first time in a given environment
Is SLAM in general used only for first time mapping within an
environment?
Yes, SLAM is used only once to build map of the environment before navigation operation. Also, In case of significant ...
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2
votes
Is SLAM done only first time in a given environment
SLAM is a recursive algorithm with no base case. I suppose you could have a termination criteria for the algorithm stating that "This Map is Sufficient", and then change your algorithm to localization....
- 503
2
votes
Accepted
Uncertainty in grid based fastslam
This depends on how you want to quantify the uncertainty. For example, you can compute the sample covariance between all state variables i.e.,
$$ q_{jk} = \frac{1}{N-1} \sum_{i=1}^{N} (x_{ij} - \bar{...
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2
votes
Occupancy grid maps
Cause of the intrinsic noise in sensory data, we have to consider a probabilistic model (mostly Gaussian) for the sensor measurements. As a matter of fact, the description and definition of the ...
- 96
2
votes
How to detect loop closures in 2D laser SLAM?
The most traditional method is to keep looking at the trajectory and see if your current location is close enough to the previously visited place. Once this happens run the ICP. If ICP converged ...
- 1,577
2
votes
Mobile Bot Maze Solving
Here's a video of a micromouse competition. The video starts with what I believe you're looking for - a mapping run.
How do you ensure you have appropriate coverage, though? It's up to you to define ...
- 15.9k
2
votes
Include information on the environment in map-aware particle filter
Answer
Create a new "probability grid" for each sensing modality and combine them after you have estimated the position of the robot in each of the many different grids.
In short, you have a ...
- 5,392
2
votes
Why visual SLAM is seldomly used in autonomous driving?
There are a couple of reasons.
Autonomous driving is all about perception and localization. Not the mapping. For localization, a simple map and GPS are enough. In terms of perception, the ...
- 1,577
2
votes
Accepted
ROS2 Map not received when using nav2_bringup
I have found the mistake, I have renamed my yaml and png map files and forgot to adjust the new png name in the yaml file.
Thank you very much for the help still akchobby!
- 21
2
votes
ROS install for Raspberrypi 4
Usually all Ubuntu versions works with some version of ROS. It depends on which ROS version you want to use. I would recommend using ubuntu 22.04 as it is a LTS version and with that ROS2 Humble or ...
- 108
2
votes
ROS install for Raspberrypi 4
First, you need to make sure in what ROS version you want to use.
If the ROS you mentioned means ROS1, then the version of ubuntu 20.04 and ROS Noetic(final release of ROS1) is recommended.
ROS1 is ...
- 191
2
votes
SLAM_TOOLBOX , topic /map is empty
Should I be sending data to the /map topic in some way, or should the SLAM Toolbox process the odometry and lidar data and publish to /map itself?
No, SLAM publishes the ...
- 6,389
2
votes
Accepted
SLAM_TOOLBOX , topic /map is empty
I’ve solved the issue, and the map is now building correctly!
The mistake was that I initially constructed the TF tree incorrectly. In my case, the ‘robot’ was the lidar itself, so I had two static ...
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1
vote
Which is a good and cheap 3D LIDAR or other options?
There is no cheap outdoor 3D LiDAR (as long as the definition of your "cheap" is under USD1000).
This might suit your purpose. There are low cost (USD100~500) 2D LiDARs. You may need to combine ...
- 1,577
1
vote
How to use a map created with odometry
Nope, most of these maps are defined as adjacency matrices not maps describing a physical scene. Moreover, switch the parity of the elements since vanilla A* algorithms on the internet use minimum ...
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