Questions tagged [visual-odometry]
visual odometry is the process of determining the position and orientation of a robot by analyzing the associated camera images.
55
questions
0
votes
0
answers
15
views
The choice of using quaternions and using gyro & accel separately in EKF
I am working on realising the self-navigation of a vehicle.
I have already written an extended Kalman filter with a state vector using position, velocity, Euler angle, acceleration, and angular ...
- 3
0
votes
1
answer
45
views
What should I use for a Visual+IMU+GPS fusion? A Madgwick or a Kalman?
I am new to robotics, and recently I am involving in a sensor fusion task using visual input (binocular at present), an IMU, and a GPS module. I have searched for related journal papers for a ...
- 3
0
votes
0
answers
23
views
LSD-SLAM vs Stereo Vision
LSD-SLAM is a monoecular SLAM system which is considered "direct", as in it does not find features explicitly like in ORB slam. The paper is available here:
https://link.springer.com/chapter/...
- 259
1
vote
0
answers
32
views
How does marginalization work in fixed lag smoothing?
I have read in SLAM papers talk about marginaliztion. I am confused about how this process works, why you do it and how it differs from global smoothing.
In particular if you're interested in Windowed ...
- 259
1
vote
0
answers
43
views
Using an optical mouse sensor for odometry?
I'm trying to use a mouse sensor for odometry on my robot. Most datasheets I have found use SPI or SDIO interfaces for communicating but my microcontroller would require an I2C interface. Would it be ...
- 11
4
votes
2
answers
116
views
Why do we need to know the translation between Camera and IMU?
In Visual Inertial Odometry, assuming the camera and the IMU are attached to the same rigid body, why isn't it enough to know just the relative rotation between the camera and the IMU? Why do we need ...
- 63
0
votes
0
answers
34
views
Stereo Bundle Adjustment
When doing stereo based visual odometry and bundle adjustment how does the stereo constraint get factored into the photometric error?
Do you use the fact the second cameras location is known wrt the ...
- 259
0
votes
1
answer
36
views
Question about bundle adjustment
When doing bundle adjustment do landmarks gets optimized as stand alone variables or are they viewed as a function of the robots first position when they are detected?
- 259
0
votes
0
answers
99
views
OpenCV: What does it mean when the number of inliers returned by recoverPose() function is 0?
I've been working on a pose estimation project and one of the steps is finding the pose using the recoverPose function of OpenCV.
...
- 205
0
votes
0
answers
16
views
What is Rotation when pose is looking back?
I've model a relative pose between two cameras. $T_0$ is origin and $T_1$ has the relative pose.
The $Camera_0$ is facing a the map point $X$, and I can get a vector $v_0$ from $Camera_0$ toward $X$.
...
- 101
0
votes
0
answers
112
views
Adding/ Subtracting vertex and edge constraints using g2o dataset in a monocular odometry project
I have come across a relatively new rotation averaging solver with full python implementation and helpful examples https://github.com/dellaert/ShonanAveraging
However, I am having a hard time ...
1
vote
2
answers
480
views
/rtabmap/rtabmap: Did not receive data since 5 seconds
trying to run RtabMap on my realsense-435 device. I've set up all the topics and made sure they are published and subscribed, nevertheless, RtabMap gives me this error:
...
- 51
0
votes
0
answers
134
views
Uncontrolled drift of Visual Inertial Odometry
I'm trying to use the VINS-Fusion package to obtain odometry for a quadcopter. The primary sensor is an Intel Realsense D435i. I've calibrated the camera and IMU extrinsics using Kalibr. IMU ...
- 1
0
votes
1
answer
699
views
How to loop over each timestep in rosbags using Python?
I am using rosbag api to record rgb, depth and imu data coming off a robot. For an offline Visual Odometry experiment, I am in need of synchronizing RGB data with the imu data at the correct timesteps....
0
votes
1
answer
52
views
How does baseline work with forward motion in Monocular Visual Odometry
In my computer vision class we are studying visual odometry. In this we calculate the Fundamental matrix using 2 frames from forward motion using the concept of stereo-vision. But in stereo vision the ...
- 1
0
votes
3
answers
949
views
Difference between motion-only bundle adjustment and pose-graph optimization
I've been trying to figure out the difference between motion-only bundle adjustment and pose-graph optimization, when talking about systems that only use cameras to estimate motion between frames, but ...
- 111
3
votes
1
answer
531
views
Calculate information matrix for graph slam
0
I am new to SLAM. I am working on graph slam where I need to do pose graph optimisation. For this requirement information matrix is required between two edges for which the transformation has ...
- 31
0
votes
1
answer
101
views
Relative scale problem
I am doing Monocular Visual Odometry, and I have problem with relative scale. Most of the time its value is between 0.8-1.1, but sometimes it goes crazy and it has value 3,4 and once it had value 25. ...
- 1
0
votes
0
answers
142
views
Pose-Graph Optimization in MATLAB does not give expected results
I am trying to optimize a pose graph I created in MATLAB using either the optimizePoses(viewSet)-function on the imageViewSet that I have or the ...
2
votes
1
answer
393
views
Visual Odometry terminology: Scale, Relative scale, absolute scale
I'm watching a MOOC about Machine Vision for Robotics, but I really do not know the meaning of some vocabulary of this domain.
For example, What does the professor mean when he says this:
However, we ...
- 189
0
votes
1
answer
152
views
Mono VIO vs. Stereo-Camera to recover Depth Information
I have a question. I have found some papers, where they use a Mono-VIO to recover depth of a scene. My question is:
Suppose I have a robot arm and attach a mono-VIO system to it. Then I move this arm ...
0
votes
1
answer
16
views
What are the parameters that I need to consider when figuring out the horizontal viewing distance of a camera mounted overhead for effective tracking?
I am currently working on developing a hybrid Indoor Positioning system where images from an overhead camera will be used to identify and track people.
I am new to the field of visual tracking and a ...
0
votes
1
answer
140
views
How can I calibrate 3 cameras without knowing global pose of the object & camera locations? How can I find the pose of each camera wrt the first one?
I have camera feed (in the form of RGB images) from 3 cameras with partially overlapping Field-of-view i.e. for the time stamp 0 to 100, I have total 300 frames or say synchronized 100 RGB frames for ...
- 15
1
vote
0
answers
1k
views
What does the normalized image coordinates imply?
In VSLAM or visual odometry, we use a camera matrix P to transform 3D scene points to 2D image points. When using homogeneous representation, we may choose the image coordinates as the normalized ...
- 13
1
vote
1
answer
147
views
How is the depth estimation done in DTAM / LSD-SLAM (direct VSLAM)?
I know that DTAM and LSD-SLAM both employ the photometric error between two keyframes to estimate the image depth. But I don't know what the photometric error describes precisely.
In the DTAM paper, I ...
- 13
0
votes
1
answer
245
views
Custom implementation of robot_localization package
I plan to implement a sensor fusion of IMU + Visual odometry using an EKF. I came across the excellent robot_localization package which does pretty much all that I want. However, I need to use perform ...
- 113
0
votes
1
answer
286
views
How to find visual odometry by video from cellphone camera mounted on robot?
I am writing codes in python for visual odometry from single camera. I used cell phone camera for testing. I took video of 35 sec with camera moving. I used code below to read first image
...
1
vote
0
answers
119
views
How does inverse compositional Lucas–Kanade algorithm work?
I am trying to understand the Lucas–Kanade algorithm since I am reading a paper in which is applied the inverse compositional Lucas–Kanade algorithm, but in order to understand the latter I have to ...
- 449
1
vote
1
answer
60
views
Problem understanding a paper about visual odometry
I am reading the following paper: SVO: Semi-Direct Visual Odometry for Monocular
and Multi-Camera Systems
, and I am having some problem understanding some concepts.
Before starting I have to say ...
- 449
1
vote
0
answers
315
views
What is the definition of the phrase "ego robot"?
What does the phrase "ego robot" mean? I see it used in the context of multi robot systems like in the paper Game Theoretic Motion Planning for Multi-robot Racing by Zijian Wang, Riccardo Spica & ...
0
votes
1
answer
107
views
Planar Robot Boundary Detection
I am tasked with building a robot that needs to localise and navigate itself on a rectangular surface (like a large desk). The rectangle's shorter sides will be marked with a red tape (or with two ...
- 11
1
vote
1
answer
124
views
How to derive the camera trajectory from ICP
This may be a very simple question so please bear with me...
Suppose I have a stationary object and point clouds, $n$ $(x,y,z)$ points, of that object taken by a moving camera at time steps $t_i$, $...
- 113
0
votes
1
answer
160
views
SLAM techniques based on contact, odometry and one front camera
Consider a mobile robot provided with a contact sensor that randomly travels in a closed environment, changing direction every time an obstacle is encountered. Is it possible to reconstruct the 2D map ...
- 101
1
vote
1
answer
181
views
How to plot the 3D camera trajectory from a VSLAM output
I am totally new to VSLAM algorithms and would want to plot the path followed by the moving camera. I am using the open source implementation of ORB_SLAM2 for a rgb-d camera on benchmark dataset. The ...
4
votes
1
answer
131
views
Performing Image alignment using pyramid levels with semi dense depth
To gain some confidence, I want to implement the camera tracking (optimization problem) discussed in Semi Dense Visual Odometry for a monocular cameraJ Engel, J Strum, D Cremers
$$E(\xi) = \underset{i}...
- 140
2
votes
1
answer
301
views
Why do strong rotations affect Monocular Vision based Visual Odometry?
In context of the paper Semi Dense Visual Odometry for a Monocular Camera J Engel, J Sturms, D Cremers
At page 7, last paragraph the author writes
The achieved tracking accuracy for two feasible ...
- 140
2
votes
1
answer
303
views
How to publish odometry from 3 wheeled omnidirectional robot?
I'm new to ROS and robotics and I'm trying to implement the ROS navigation stack in a 3 wheeled omnidirectional robot. I already made the map using RTABMap but now I'm stuck in the 'Publishing ...
- 21
1
vote
0
answers
84
views
Map initialization problem in Mono SLAM
I'm reading and trying to implement the paper Monofusion(V. Pradeep, C. Rhemann, S. Izadi, C. Zach, M. Bleyer and S. Bathiche, "MonoFusion: Real-time 3D reconstruction of small scenes with a single ...
- 11
0
votes
1
answer
65
views
Which algorithms to locate a static 3D object relative to a moving camera/IMU?
I am using typical setup with camera and IMU as found on a smartphone. Using this, I would like to estimate the relative pose between the camera and an object (for simplicity, let's say a cube). The ...
3
votes
0
answers
47
views
Accuracy of monocular visual-inertial odometry
I am currently considering to use monocular visual-inertial odometry (VIO) to localize a smartphone relative to a known object. Now, what I would like to understand is, what kind of accuracy I can ...
2
votes
2
answers
163
views
Is pose estimation using images necessary in visual-inertial SLAM
In visual SLAM, pose estimation is performed between two adjacent frames or keyframes using feature detection and pose estitmation from corresponding features.
However in visual-inertial SLAM, pose ...
- 273
9
votes
1
answer
311
views
In practical terms, how close is the accuracy of camera-based visual odometry/SLAM methods to lidar-based methods for autonomous car navigation?
Benedict Evans, a general partner at Andreessen Horowitz, claims that “almost all autonomy” projects are using lidar for SLAM, and that not all of them use HD maps.
An MIT group is testing self-...
- 91
2
votes
1
answer
170
views
SE3 composition operator gives unexpected results
Given Data and Algorithm
I have a stream of SE3 poses supplied by a basic wheel encoder odometry through ROS message passing system. Odometry publishes data in traditional to ROS ENU coordinate frame ...
- 131
2
votes
2
answers
242
views
Scale estimation in datasets for monocular odometry
Suppose I've developed a monocular SLAM or odometry algorithm. Then I want to test it on some dataset, for example KITTI, TUM etc. How should I deal with the absolute scale in this way? Thanks.
- 31
1
vote
1
answer
370
views
Camera ego-motion estimation via dense optical flow
Help me please resolve some questions in the article
1) "A Robust Method for Computing Vehicle Ego-motion", Gideon P. Stein et al.
According to this paper we can find three components of motion (...
- 31
0
votes
2
answers
180
views
TU Munich Monocular Visual Odometry Dataset has NaN values in the ground truth data.
I am trying to use the motion sequences in the dataset to create trajectories for VR systems. A major portion of the ground truth data in almost all sequences has NaN values. Is there any other source ...
- 3
1
vote
0
answers
133
views
Camera calibration sequence with ground truth data
I'm looking for a SLAM dataset (monocular or stereo) specifically with a checkerboard, meaning the camera always has a checkerboard in frame.
Most popular datasets provide calibration sequences, ...
- 111
2
votes
0
answers
84
views
Effectiveness of visual odometry algorithms (CPU usage)
My robot needs to obtain visual odometry, with a condition that the used algorithm has to have as low computational requirements as possible and the used camera/sensor shouldn't be very expensive. The ...
- 121
1
vote
0
answers
238
views
EKF based SLAM, marginalization and key-frames
I have a couple of tightly related questions regarding EKF-based visual SLAM. It is common in the Kalman based VSLAM litterature to marginalize 3d points and past poses. Condsidering the EKF as a ...
- 380
2
votes
0
answers
93
views
Consitent Scale in Monocular pose estimation
I just wanted to know if scale is conserved across multiple images, when doing a process such as monocular odometry. I know in reality the scale tends to drift over time due to accumulation of small ...
- 1,661