9
votes
How do monocular visual odometry algorithms work?
Monocular vision is a difficult and very interesting, particularly in its application to the general navigation problem. I will make an attempt at answering your questions, but if you find anything ...
- 926
7
votes
Odometry vs Dead-reckoning
Dead reckoning is determining pose (position and rotation) using speed estimates from sensors. For example, you know your initial position and use sensors such as encoder, accelerometers, gyros, etc......
- 345
4
votes
Accepted
Problem understanding a paper about visual odometry
So SVO works a bit differently then other VO systems as it uses dense image alignment. You need to understand this concept first before understanding SVO. Look up Lucas and Kanade image alignment. The ...
- 1,901
3
votes
Wheel Odometry Covariance Matrix for Custom Robot
The covariance matrix of the control inputs is measured and known.
That is, following the EKF equations on this page, the covariance of the control, $Q$ is (often) a diagonal matrix, where the ...
- 5,392
3
votes
Need help regarding odometry using Encoder motor and raspberry pi
You could maybe use Matlab to plot the position of your vehicle? This is how I'm trying to do that:
I have a 'logging'-program running on the Raspberry Pi that counts each sampling time the pulses ...
- 155
3
votes
Need help regarding development of Extended Kalman Filter for sensor-data fusion of odometry and IMU data
Adding to the above, my favorite way to debug a misbehaving filter is to isolate each step.
Make sure your prediction step works before correcting it. Your bot should drive straight right with 0,0,0 ...
- 5,392
3
votes
Public dataset for monocular visual odometry
http://vision.in.tum.de/data/datasets/rgbd-dataset
This is a set of recordings for the Kinect and Asus Xtion pro, which are all indoors (in offices and a hangar). It comes with precise ground truth ...
- 176
3
votes
Public dataset for monocular visual odometry
This is another more recent one, based on the paper A Photometrically Calibrated Benchmark For Monocular Visual Odometry by Engel et al:
http://vision.in.tum.de/data/datasets/mono-dataset
This gives ...
3
votes
How to do odometry for 4 mecanum wheeled robot?
In order to transform encoder signals to robot motions a kinematic model of the robot is needed. In some cases this is very simple, just including the gear ratios and a heading angle (e.g. with ...
- 6,682
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
What is inverse depth (in odometry) and why would I use it?
In addition to the reasons mentioned in other answers about the numerical conditioning of inverse depth, a major reason for this term to appear in specifically visual odometry literature is in the way ...
- 324
2
votes
Need help regarding development of Extended Kalman Filter for sensor-data fusion of odometry and IMU data
You should first validate your filter is working before second-guessing your modelling choices. But I agree both those filters look OK (although I did not double check all the maths) and both of your ...
- 902
2
votes
Differential GPS or Simple GPS for Robot navigation and odometry?
Do not give up on encoders. They are a great complement to GPS. I don't know what precision you want to reach, or what terrain your robot will operate in, but wherever it will be, encoders will give ...
- 953
2
votes
Accepted
Markov Localization using control as an input
Multi-dimensional models
In the 2D case, $x_t$ is a vector with two components (e.g. position in $x$, $y$), but why stop at 2D? Often, the state vector $x_t$ will have your position in two or three ...
- 450
2
votes
Accepted
Wheel odometry simulation using ground truth
You can't just take the ground truth states and get wheel encoder positions, or vice-versa, because the robot is nonholonomic. Nonholonomic is a fancy word that means "path dependent," essentially, ...
- 15.9k
2
votes
Encoder for odometry (Wheel vs motor)
Since it's the wheels which change the robot's pose in the environment, I'd suggest putting the encoders to the wheels. Especially if the motor and the wheel are only connected by a chain, introducing ...
- 821
2
votes
Accepted
Why the IMU measurements only accumulate drift in 4DOF
Correct, it's all about the gravity vector. I would argue that it is NOT necessarily possible to get the gravity vector out of the measurement, but that's because it's possible to put the IMU in a ...
- 15.9k
2
votes
Full 3D Pose (Scale, Rotation and Translation) Estimation using Gyro and Acceleromter sensors fusion
The packages you've found don't estimate scale or 3d pose because that's not really feasible using just an imu. The only way to get 3d pose from an imu is to integrate acceleration (adjusting for ...
- 2,814
2
votes
Accepted
How to properly initialize every new pose in a Visual SLAM algorithm (namely DSO)?
DSO initializes the scene and camera poses with a specific scale factor such that the average inverse depth of the pointHessians is one. After the initialization the first two frameHessians are led ...
- 36
2
votes
Lost on Graph slam's loop cloursure
The GraphSLAM algorithm from the paper you linked does not have a loop closure mechanism in the sense of a dedicated procedure for finding correspondences between landmarks observed at different nodes ...
- 341
2
votes
How can I calculate odometry given two poses?
Those POSEs are not 3D vectors or a 3D coordinate point. As such you can't subtract.
A pose is a state vector, and the last value is an angle.
From this, how can you calculate odometry?
- 71
2
votes
Odometry using wheel encoder with no differential drive
So long you have a sensor to read the angle of the steering wheel, you can use the bicycle kinematic model to compute odometry for an Ackermann drive platform, e.g. a car:
$$
\begin{align}
\\
\dot{x}...
- 1,363
2
votes
How to actually fuse sensor using Extended Kalman Filter
I've never worked on Mecanum wheels before so I researched a bit. One of the first things I look for is there has to be a way to combine all of the encoder velocity measurements. Apparently, Jacobian ...
- 21
2
votes
Accepted
How to reset odom positions of robots while setting initial positions of robots in gazebo simulation through launch file
Usually, robot's float a topic (eg /mobile_base/commands/reset_odometry for TurtleBot) to reset the odometry.
The URDF for the Rosbot2.0 uses Skid Steer plugin. ...
- 215
2
votes
odom frame behaves mischievously in rviz when Configuring Robot Localization with error message TF_OLD_DATA
If you are working on a real-robot, set use_sim_time to False for each node, otherwise set it to ...
- 93
1
vote
Robot localization using sensor fusion (How to model the Extended Kalman Filter)?
This is the advice I gave to BOB but will be useful for you as well.
I recommend you to run an ekf slam tutorial code and analyse it. There is a perfect one for you: robots.ox.ac.uk/~SSS06/Website/...
- 1,577
1
vote
In practical terms, how close is the accuracy of camera-based visual odometry/SLAM methods to lidar-based methods for autonomous car navigation?
In other words, could this difference noticeably impact safety or reliability? -> not at all in my opinion.
What important in autonomous car navigation is localization stability rather than the ...
- 1,577
1
vote
Why use GraphSLAM?
I can already determine the path using forward velocity and angular velocity
If you already know the exact path of robot, you dont need SLAM algorithm, you just have to integrate your sensor ...
- 384
1
vote
EKF implementation on odometry/IMU
Try this dataset, Localization and Mapping Dataset. It will be helpful for your problem.
1
vote
Accepted
Ackermann Motion Model Does not Drive in an Arc, but Turns on the Spot
The first ackermann model presented is based on dead reckoning, i.e. it needs wheel encoders. The ackermann model in edit 2 is based of velocity.
It can be found here:
https://pdfs.semanticscholar....
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