johnfertitta's profile - activity

It turns out the jar is not bad after all. I can create and use objects in nav_msgs without runtime errors. The errors only occurred when I was trying to use OccupancyGrid with a service to retrieve a map.

This seems to be a problem with rosjava services and not with the compiled jar.

org.ros.android comes from the rosjava.android packages (http://code.google.com/p/rosjava/source/checkout?repo=android). The other missing jars are most likely built when you build the rosjava package. The manifest.xml file of a package specifies dependencies and when you run "rosmake" on the package it will generate the jar files for each of those dependencies.

I recommend installing rosjava and rosjava.android from source. Here's (hopefully) a helpful guide:

1) Install ROS electric, unstable, or later

    a.  ‘sudo apt-get install ros-electric-desktop-full’ (for electric)

2) Clone the latest rosjava source from googlecode into a directory in your ROS_PACKAGE_PATH

    Install Mercurial (hg) : ‘sudo apt-get install hg’

    Go to http://code.google.com/p/rosjava/source/checkout and Follow “Command-line access” instructions

3) Run ‘rospack profile’ to update your environment

4) Build rosjava

    ‘rosmake rosjava’

Continue for Andorid setup

1) Install eclipse

    ‘sudo apt-get install eclipse’

2) Install the Andorid SDK

    Follow the instructions at http://developer.android.com/sdk/index.html

3) Clone the latest rosjava.android source from googlecode into a directory in your ROS_PACKAGE_PATH

    Go to http://code.google.com/p/rosjava/source/checkout?repo=android and Follow “Command-line access” instructions

4) Run ‘rospack profile’ to update your environment

5) Build rosjava.android

    ‘rosmake rosjava.android’

From here you should have a working environment. To run the tutorials, run "rosmake" on the one you want, then import it into eclipse. If you're doing Android dev you may need to import android_gingerbread or android_honeycomb_mr2 into eclipse also, and add them as project references.

android_gingerbread and android_honeycomb_mr2 are the packages (eclipse projects) that provide org.ros.rosjava.android.

To create a new rosjava package you can follow the instructions here : http://www.ros.org/wiki/rosjava/Build

The only difference for android is that the build.xml file should be :

<?xml version="1.0" encoding="UTF-8"?>
<project>
  <property file="ros.properties"/>
  <include file="${ros.pkg.rosjava_bootstrap.dir}/android.xml"/>
</project>

You'll also need to set up the right exports. Add this to your manifest.xml file:

<export>
  <rosjava-android-lib target="android-9" />
  <rosjava-src location="src" />
  <rosjava-src location="gen" />
  <rosjava-src location="res" />
</export>

After running rosmake you should be able to import your the package into eclipse and begin development.

I've recently started working with ROS java and I've had decent success so far, however nav_msgs are not working. In my Android project I'm attempting to use OccupancyGrid from nav_msgs. I included nav_msgs as a dependency in my manifest, ran rosmake, and have a nav_msgs jar file. I can reference the jar from my project and build the Andorid app, however, in run-time I get ClassNotFound exceptions when it tries to use nav_msgs.

Is there anything special that needs to be done to build jars for android? My project used geometry_msgs and std_msgs without a problem. Also, if I remove support for my map, thus eliminating the need for nav_msgs, my code base runs perfectly fine and the subscribers and publishers work as expected.

By "local obstacle detection" do you just mean LaserScans are showing up? Or are the obstacle and inflated_obstacle topics being published?

I'd open up rxconsole after launching your nav stack and see if any of your nodes are crying for help. If the console is spitting out many errors, it's best to tackle them one at a time. Try posting whatever (assuming there are any) errors into your post if the solution isn't obvious.

PS In addition to gmapping not producing a map, it sounds like you have some serious odometry drift if you're off by 45 degrees after a single rotation.

I'm trying to run the ros navigation package with slam_gmapping on our simulated robot. While the code runs and builds a map that looks accurate I am seeing issues when I try to navigate the robot. Even with fixed_frame set to /map in RVIZ both the map and robot move in the display. To explain better, if I set fixed_frame to /map and then teleop the robot 360 degrees the map is off 45 degrees from it's starting orientation. It's my understanding that this same action should result in the map not being off, in fact the map shouldn't rotate at all with it set as the fixed frame, only the robot should be moving.

EDIT: It actually appears that the map isn't being published at all. slam_gmapping is offering a map, but when RVIZ subscribes it is not receiving one. The rotation issues appears to be just the obstacles. So local obstacle detection is working, but they are not being placed on the map. Also, it should be noted that we are not using a static map.

Has anyone seen this happen and could any point my in the direction of a parameter to check?

We are using the erratic diff drive plugin which is providing odom and a sicklms. Just as a note, the odom from erratic looks correct.

Thanks.