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I have read Euler Angle transformation but it does not seem to give me an answer for it since it only considers local frame only?

I am fairly new to ros and robotics.

I am currently dealing with geometry_msgs/PoseWithCovarianceStamped and all pose data from sensors are written in world frame, i.e. frameId is world.

Is there any way to convert this frame to local frame in which the robot itself is at origin? What I want to do eventually is to find poses which go backwards against a destination for next step.

Please advise me about above. Thank you so much in advance.

Oh yeah, covariance of EKF might be a key to solve this. I will test on the value. Thanks a lot for your advice.

Actually data is not lagged but some sensor pose is behind another sensor's pose when neighboring time stamps are fairly close. So I guess this is due to sensor noise. I am not too sure if history length can deal with this problem. Thank you for your advise, Nicholash.

This question might not be regaring ROS itself but I need your help on below issue regarding robot pose by sensor fusion with EKF.

I am currently working on coding sensor fusion of a wheel based robot pose from GPS, Lidar, Vision and Vehicle measure. Its model is basic kinematics using EKF and no discrimination against sensors i.e. data comes in based on time stamp.

I have difficulty to fuse those sensors due to following issue; Sometimes when the latest incoming data comes in from different sensor from a sensor gave previous state, the latest pose of the robot comes in behind previous pose. Therefore data fusion does not get so smooth and zigzag-ed as a result.

I would like discard data which plots behind/backwards of the previous data and take data which poses always forward/ahead of previous state even when sensor to provide the data changes between timestamp t and timestamp t+1. Since the data frame is global frame, it is impossible to rely on its x coordinate in minus to achieve this.

Please let me know if you had some idea on this. Thank you so much in advance. Best,

Hi

I am new to linux and ROS. I tried to install the ROS following http://wiki.ros.org/indigo/Installati... . At the step of sudo apt-get install ros-indigo-desktop-full, I get below messages. I cannot install ros-indigo-perception even if i go install all the depends of it. I tried to solve this by sudo apt-get install libsdformat1 , this did not help this situation.

My environment is followings; Distributor ID: Ubuntu Description: Ubuntu 14.04.4 LTS Release: 14.04 Codename: trusty

Thank you so much for your help in advance.

Reading package lists... Done Building dependency tree
Reading state information... Done Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:

The following packages have unmet dependencies: ros-indigo-desktop-full : Depends: ros-indigo-perception but it is not going to be installed E: Unable to correct problems, you have held broken packages.