Questions tagged [ekf]

the extended Kalman filter, a filter for nonlinear state estimation.

Filter by
Sorted by
Tagged with
0 votes
0 answers
38 views

Issues while setting up EKF for Ackermann Steered Robot

I have an Ackermann steered robot with optical flow sensor mounted at an offset from base_link x = 0, y = 0.4 , z = 0.15 and ...
Rakshit Soni's user avatar
1 vote
1 answer
38 views

EKF filter node not working correcty

I'm using a two-fixed-wheeled differential robot with Nav2 on ROS2 Humble, I succesfully achieved to code a standard odom publisher which publishes on /odom and /tf topics like this: ...
Jesús 's user avatar
0 votes
0 answers
9 views

Extended Kalman filter + IMU sensor

I'm trying to implement an extended Kalman filter to the accelerometer and gyroscope. However, the result is not good. It seems to have some errors in my codes. I check the equation and code again but ...
davidchu's user avatar
1 vote
0 answers
23 views

localization in pivot turn

I have a question about position estimation when a robot performs pivot turn. In pivot turn, it is ideal for only the robot's yaw angle to change, while the x and y positions remain constant. But, I ...
mamoru's user avatar
  • 11
0 votes
1 answer
23 views

Velocity based motion model (dead reckoning)

I'm trying to understand the derivation of the velocity based motion model to implement an EKF: But the problem is, that I cannot find any derivation/explanation. Mostly there is only a visualization ...
user39812's user avatar
0 votes
1 answer
62 views

Robot_Localization Local/Global ekf nodes

I have a doubt regarding the use of Robot_localization. I was watching this tutorial: https://navigation.ros.org/tutorials/docs/navigation2_with_gps.html in my case I have a real robot (equipped with ...
Supermax182's user avatar
0 votes
0 answers
59 views

EKF not providing good position estimation

I am working on a robotics project and I am using the package robot_localization in ROS2. I am trying to fuse the wheel odometry and IMU data, but I am struggling a lot to make it work. I've read a ...
João Victor Aguiar's user avatar
0 votes
1 answer
62 views

Diff-drive robot estimation sliding sideways with robot-localization

I'm trying to configure an ekf_filter_node. I started by adding just the odom topic from a ros2_control DiffDriveController in gazebo. For some reason, the robot starts sliding sideways in odom (in ...
Samuel Lindgren's user avatar
0 votes
1 answer
40 views

UKF position data closely match slam absolute pose regard wheel odometry

I have a specific question related to a robot localization package. I've been trying to get an answer on the Robot Stack Exchange for quite some time now, but I haven't received a response. I'm ...
Spectra543's user avatar
0 votes
0 answers
74 views

robot_localization package position output is the same as input absolute pose

Hello my question is whether this type of output is a proper output? I fuse absolute pose from slam and fuse linear velocity from wheel odometry, but the filter output position data is the same as the ...
ruj's user avatar
  • 1
0 votes
0 answers
33 views

Robot Localization pkg / Motion Model prediction step

As I was investigating the transition functions in the prediction step in the ROS Robot Localization pkg (ekf.cpp) . I found for the orientation equations there are as follows: Roll angle is the ...
jf2's user avatar
  • 1
2 votes
1 answer
333 views

Frequency Limitation in robot_localization's EKF Node

I'm using version 2.7.4 of the robot_localization package for ROS Noetic. I'm currently utilizing two nodes of the package: EKF Local Node: Fuses data from an IMU (100Hz) and wheel encoders (4Hz). ...
user2454945's user avatar
0 votes
1 answer
186 views

EKF of robot_localization have a delay compared to GPS data

I am using ros2 humble and the extended Kalman Filter from the robot_localization package to get both the odom -> base_link and ...
Timothée's user avatar
0 votes
0 answers
27 views

EKFSLAM with LiDAR and IMU + GPS localization module

There are many resources that relate to EKFSLAM based on the presence of only a LiDAR unit, which localize both the vehicle and the detected landmarks. I see that they often use state vectors that get ...
mOSRobots's user avatar
2 votes
1 answer
252 views

robot_localization GPS causing large drift/covariance spike

I am trying to implement the dual ekf navsat example on my real-world robot. The local EKF with wheel odometry and IMU works quite well and has no issues. As far as I can tell, my global EKF ...
Leetfail's user avatar
0 votes
1 answer
96 views

navsat_transform node doesn't publish utm_transform

Hi, please, help me with following issue, i've been trying to solve it for a week already... Can't make my navsat_transform node publishing utm_transform. And odometry/filtered from EKF always has ...
user avatar
0 votes
2 answers
176 views

Odometry into EKF for localization

I want to fuse a Lidar-Odometry into my EKF where I'm already using encoder, IMU, GPS. The odometry has as output a delta pose, how to put that into the filter? How to deal with the covariances?
frank-resq's user avatar
0 votes
0 answers
192 views

MPU6050 providing gyroscope values for linear acceleration

I am using this ROS2 driver to connect my MPU6050 to RPi 4 running ROS2 humble. It outputs an IMU message containing linear acceleration and angular velocity. The linear acceleration values seem to be ...
Redstone's user avatar
0 votes
1 answer
10 views

Issue in using IMU MPU 6050

Hello, I have been trying to implement MPU 6050 imu sensor using, MPU SERIAL NODE , when i initially run the node, IMU values seem fine, for example, linear accelerations in x, y, z directions come to ...
user avatar
0 votes
1 answer
7 views

What is the purpose of splitting SLAM odom and EKF odom frames in waypoint_nav?

I have a robot somewhat similar to the clearpath husky . In their gmapping launch file, they have their odom frame set to 'odom_gmapping'. config shown here: ...
Chase's user avatar
  • 22
0 votes
1 answer
149 views

[Robot Localization] How to use absolute orientation from IMU with absolut positionning from visual SLAM

Hi, I'm quite new to ROS and robot_localization so I'm getting confused really fast with TFs. I've been using for some time now a visual SLAM algorithm that works fine and I'd like to slowly improve ...
user avatar
0 votes
0 answers
74 views

Nonlinear continuous system function of IMU sensor fusion robot

For my robotics course I have to implement the nonlinear continuous system function for a mobile robot that is equipped with a GPS receiver and an IMU consisting of an accelerometer and a gyroscope. ...
exzoran's user avatar
0 votes
1 answer
9 views

Jiggling tf Tree After fusing Odometry with IMU

I am using ROS NOETIC and Pioneer3DX as the mobile robot which publishes Odometry info into /RosAria/pose topic as nav_msgs/Odometry message. Phidgets Spatial IMU is being used which published the IMU ...
user avatar
0 votes
1 answer
77 views

what exactly is 'observation model' for a robot

In my journey to understand the Kalman filter, I understood how a state model representation is derived for a robot and why(to get the robot state for a given input u) it is required. $$ \boldsymbol{...
krishna's user avatar
2 votes
1 answer
70 views

Confused with EKF Localization

I have been trying to understand EKF localization from Probabilistic Robotics by Thrun Burgard and Fox. There the covariance prediction is given by $$\overline{\Sigma }_t=G_t\Sigma_{t-1}G^T_t+V_tM_{t-...
Essam's user avatar
  • 141
2 votes
0 answers
50 views

Why is the EKF approximated this way?

I'm a student that recently started taking a course on cognitive robotics. The book I use is Probabilistic Robotics by Thrun Burgard and Fox. In the EKF algorithm, we linearized the action model in ...
Essam's user avatar
  • 141
0 votes
1 answer
166 views

Extended Kalman Filter and PID controller

I'm trying to build a model based on tracking an object in 2-D using MATLAB (time-varying system). I built the model using an Extended Kalman Filter and a PID controller. I have a doubt regards the ...
marcck's user avatar
  • 11
0 votes
1 answer
81 views

Robot_localization ekf node does not subscribe to Odom topic

Hello, I am trying to fuse my odometry from my 2D differential drive robot, with my imu using the ekf from RL. The odometry works fine on it's own, but I think I must be missing something simple in my ...
user avatar
0 votes
1 answer
24 views

IMU sensor coordinates for EKF

Hi, I am using ekf to fuse multiple IMU. I was reading this portion ...
user avatar
0 votes
1 answer
115 views

Derivation of EKF slam landmark initialization

I have read a couple posts which gives the formula for initializing a new landmark in EKF slam but the derivation is not given. EKF-SLAM initialize new landmark in covariance matrix Could someone ...
FourierFlux's user avatar
1 vote
0 answers
670 views

robot_localization not fusing imu data

According to the documentation in : http://docs.ros.org/en/noetic/api/robot_localization/html/state_estimation_nodes.html I was able to transform the imu data header fram from "imu_link" ...
sdu568's user avatar
  • 11
1 vote
1 answer
259 views

EKF slam vs global bundle adjustment

How does EKF slam and the covariance matrix interact with global bundle adjustment? In particular the covariance matrix gives you a confidence on location but global bundle adjustment does not. How do ...
FourierFlux's user avatar
1 vote
1 answer
3k views

robot_localization EKF node does not publish on /odometry/filtered (ROS2 Foxy)

I am using ROS2 Foxy and Gazebo 11 in Ubuntu 20.04. I have a URDF description of a mobile robot that uses 4 wheels for mecanum drive. Using the robot_localization package, I am creating an EKF node ...
Harshit Kaushik's user avatar
1 vote
0 answers
683 views

robot_pose_ekf won't publish any messages

I am having trouble getting the robot_pose_ekf package to publish messages. I launch it with this launch file. ...
Doug's user avatar
  • 11
0 votes
1 answer
70 views

how to use IMU sensor with relative orientation data in navsat transform node

Hi, I am working on fusing visual odometry, IMU, and gps sensor by using a robot localization package. There are a couple of issues with my IMU data 1) it's not giving absolute orientation or heading ...
user avatar
0 votes
1 answer
415 views

Derive the system's dynamics function and the Jacobian Matrix G of Extended Kalman Filter of a differential drive robot on a 2D plane

I have found the following answer on the system's dynamics function and what the Jacobian matrix G of the Extended Kalman Filter look like for a 2D robot with a differential drive. Taken from slides ...
Gabriele's user avatar
  • 163
0 votes
1 answer
5 views

EKF start to predict after amcl stop sending pose

Hello, I'm trying to use robot_localization to fuse amcl_pose with encoder odom, and latter GPS. The experiment is basing on Turtlebot3, gazebo and ros2-foxy. It's working well if the robot is moving. ...
user avatar
0 votes
1 answer
17 views

navsat_transform_node geographicErr

Hello, I am usinf the robot_localization_package to localize a differential drive robot. In my setup, I follow the guidelines of the package documentation about fusing the GPS with dead reckoning and ...
user avatar
0 votes
1 answer
9 views

robot_localization (ekf node) output is not stable for a long time

Hi. I am using ekf_localization_node for fusing imu, wheel odometry and amcl_pose ( My config is as follow ) The reason why i am using amcl_pose; When i use ...
user avatar
1 vote
1 answer
338 views

No difference between UKF and EKF for SLAM

I built EKF and UKF SLAM algorithms. The problem is that I expected to see a difference because of the more precise approximation of the system in the UKF. Here's a screenshot from the estimated path ...
muller135's user avatar
0 votes
1 answer
15 views

robot_localization IMU yaw velocity causes vertical drift

Hi, I am using robot_localization's EKF node with my robot's wheel odometry and an IMU. My configuration file is the following: ...
user avatar
1 vote
0 answers
56 views

SLAM - Angle calculation failure ?-EKF

i am currently building up a EKF SLAM. I dont know where my mistake is but i think it has something to do with the angle my robot is driving towards but im not completly sure. First i thought it could ...
muller135's user avatar
0 votes
2 answers
13 views

seeking clarity regarding the 'world_frame' parameter in ekf_localization node

I have spawned two husky bots (namespaced husky_1 and husky_2) in the Gazebo world. I am ...
skpro19's user avatar
  • 314
0 votes
0 answers
79 views

EKF Update Step measurement data doesnt fit state vector

I have an EKF SLAM Algorithm which tries to estimate the robots position (X,Y,Theta) + the X,Y coordinates of several landmarks. Like in the posted algorithm i have a range/bearing sensor. I ...
muller135's user avatar
0 votes
1 answer
10 views

Using only velocity in robot_localization

Hey guys, I'm using robot_localization ekf on ROS2 Foxy to fuse two odometry sources. I am working in 2D so only x, y and yaw is used and the two_d_mode is set to true. I was trying to use only the ...
user avatar
1 vote
1 answer
155 views

EKF SLAM Prediction Step

My question relates to the prediction step in EKF SLAM when we get measurements. This is a question I've encountered while implementing EKF SLAM in ROS. At the beginning of the SLAM loop, we predict ...
Pedro's user avatar
  • 111
0 votes
1 answer
13 views

Need help locating 'ekf_localization node' inside 'robot_localization' package

I naviagted to the husky_control package using roscd husky_control. There exists a launch file inside the ...
skpro19's user avatar
  • 314
3 votes
1 answer
633 views

What's the correct approach to merging of localization and odometry data?

We've got a mobile platform with a source of odometry and an IMU, which are merged in an EKF filter (robot_localization node), producing continuous odom->base_link transform. The robot is also ...
mayor_Burns's user avatar
0 votes
1 answer
466 views

Is the covariance matrix in the extended Kalman filter guaranteed to be positive definite (ignoring numerical errors)?

I understand that due to numerical errors (e.g., round off error and machine precision) that the covariance matrix may not be positive definite, but if computers had infinite precision, is the ...
Ralff's user avatar
  • 345
0 votes
1 answer
2 views

Why are the state variables passed into the filter not equal to the state variables defined by each [sensor]_config matrix?

I am trying to get a deeper understanding on how ekf_localization_node works. At the moment I am stuck in interpreting the output of the debug file. In particular, from the output of that file, I am ...
user avatar

1
2 3 4 5 6