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2015-08-26 21:29:18 -0600 commented question Moving a Husky A200 in Gazebo using Navigation Stack

I've asked our support team to drop in here to point you to the right navstack example.

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2015-06-30 17:24:14 -0600 commented answer How to move Clearpath Husky A200 by a specific distance by publishing to a topic?

The skid-steer/off-road nature of the platform means that ded-reckoned turns can't be performed with any accuracy whatsoever. As well, since the majority of users wrap some kind of high-level autonomy around it, we didn't want to add a feature which would go unused at best and confuse users at worst

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2015-06-24 13:41:17 -0600 commented question How to use the serial port on Turtlebot?

Are you referring to a Turtlebot 1 or 2?

2015-06-24 13:36:16 -0600 answered a question How to move Clearpath Husky A200 by a specific distance by publishing to a topic?

Writing a simple node in rospy is probably the fastest way to get this done. The Husky driver itself doesn't have any position inputs, but it does publish a standard odometry topic which you can subscribe to to check an estimate of distance traveled purely based on encoders.

2015-06-24 13:31:51 -0600 marked best answer robot_pose_ekf and GPS

Hi all,

We're porting some of our internal code over to ROS-standard nodes for release, and I've got two questions related to robot_pose_ekf. For background, I have been working primarily from this tutorial (which advises adding a GPS as a VO sensor) and this ROS Answers thread.

Initialization

Is there a reason that this will only initialize on odometry data if it's available? I don't want our odometry publisher to know about the GPS sensor, so it would be ideal if there was a setting to allow it to "snap" to the VO data when it's first received. I can add this and submit a patch, but I wanted to see if there was something I was missing first.

Corrections

Given my review of the source, the VO data is used in a relative sense, same as the other data. Though this makes sense for true visual odometry (scan matching, etc), this isn't the standard way that GPS data would be used for correction. In fact, I'm pretty sure it means that we lose the benefit of the global reference frame the GPS provides.

Given a quick once over on the core code, there doesn't seem to be an explicit correction step at all. Am I missing something?

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2015-06-24 13:31:47 -0600 answered a question robot_pose_ekf and GPS

As part of ROS Answers cleanup week: Many companies/organizations/people are now using robot_localization instead of robot_pose_ekf

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2015-04-07 14:33:42 -0600 answered a question Link https://kforge.ros.org/megaslam/imu_filter does not work

kforge was shut down a while ago, and I don't believe that megaslam was ever moved to github. I suggest looking at http://wiki.ros.org/imu_filter_madgwick as an equivalent package.

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2015-02-10 13:33:16 -0600 commented question velodyne_driver: will you provide a model for the VLP-16?

I can't speak for @joq, but it is unlikely Clearpath will contribute/test unless we start working with the VLP-16.

2015-02-05 17:31:51 -0600 commented answer Issues launching ROS on startup

@julien: I'm not Mike, but I know we use it to run our Jackal, which is Indigo-only. Have you tried using

sudo apt-get install ros-indigo-robot-upstart

to install it? Instructions to use it are on both the ROS wiki and its github page.

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2015-01-27 23:33:12 -0600 commented answer Information about Turtlebot2
  1. Yes, it's Gazebo.
  2. Most manufacturers don't sell TurtleBots with arms due to the lack of quality low-cost arms.
  3. In the future, please post this as a separate question so others can find it easier.
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2015-01-17 11:29:36 -0600 commented question No data from applanix_driver

I don't know if anyone here has tried the driver on Indigo. Would it be possible for you to post a pcap file?

2015-01-12 20:34:53 -0600 answered a question Velodyne rawdata.cc does not appear to read hardware time stamp

I believe you are correct. The Velodyne driver was originally written for the -64 model which has a very similar protocol, but no GPS. I did the first validation of the -32 for Jack, because he only had a -64 on hand, and no changes were required to the base code. Since that wasn't really requested by anyone at the time (Clearpath being the only -32 user), the extra code to handle the GPS wasn't added.

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2014-12-11 08:53:14 -0600 commented answer Sub meter ROS compatible GPS

I can't think of any database, no. AFAIK, GPS devices which can't be configured for NMEA output are rare.

2014-12-11 08:43:42 -0600 commented answer Set model and link states of Clearpath Husky-Grizzly in Gazebo

Not that I'm aware of. What do you need to do with xacro after it's spawned? If you're wanting to expand the model, I'd personally probably create a xacro beforehand and pass that in to the spawn pipeline.

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2014-12-10 07:18:36 -0600 answered a question Sub meter ROS compatible GPS

Clearpath tends to supply the NovAtel SMART-6 when clients need such accuracy. It'll go down to 2 cm if the right upgrade options are selected, a base station is available, and everything's configured properly (warning: Don't underestimate the configuration time). It works with the standard navsat driver as well.

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2014-12-08 12:54:22 -0600 answered a question Usage Map from ROSCon 2014?

Do you mean "The ROS ecosystem: Impact, insights, and improvements"? Slides, Video

2014-12-06 17:58:52 -0600 answered a question how to use imu_um7 in Ros?

The UM7 doesn't work with the UM6 driver, it's a different protocol. We investigated doing a "quick port" for the community, but discovered it wasn't a "quick port" sort of task.

2014-12-06 17:55:40 -0600 commented answer Set model and link states of Clearpath Husky-Grizzly in Gazebo

Normally, we try to interact with robots as if they're real. That is, using topics like cmd_vel. Have you tried that? For example, rostopic pub /cmd_vel geometry_msgs/Twist -r 100 '[0.5,0,0]' '[0,0,0]' (see http://www.clearpathrobotics.com/blog... )

2014-12-04 23:47:19 -0600 answered a question Set model and link states of Clearpath Husky-Grizzly in Gazebo

What states are you setting and what topics/tfs are you monitoring in rviz? If you're changing the position of the robot directly and you've got rviz set up to monitor odometry (or something equivalent), this would be expected behaviour. After all, the robot wheels (real or simulated) haven't moved, and that's needed for odometry to change.

2014-11-19 19:57:54 -0600 commented answer Which topic should I publish path to?

@ahendrix: Please note that Clearpath didn't write this particular tutorial (though in our opinion, it's very well written).

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2014-11-18 17:19:19 -0600 answered a question 3DM-GX3-25 throws std::runtime_error() "Time is Out of Dual 32-bit range" on Ros Fuerte/Ubuntu Precise

I'm adding a note here because this was the top Google result when I searched for the term. In my case, I ended up stripping out all calls to the Time library I could directly find, including the basic now() calls, without effect. I hypothesize it may have had to do with VM clock jitter, as moving to physical hardware fixed it immediately.

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