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2020-09-16 07:51:35 -0500 asked a question Does hector_mapping use IMU data for 2D SLAM?

Does hector_mapping use IMU data for 2D SLAM? Does hector_mapping (or hector_slam) use IMU data for 2D SLAM? The paper m

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2020-09-13 02:57:51 -0500 commented answer Problem with TF Tree in RPLidar Hector SLAM and Navigation

That seems to be an issue regarding tuning your dwa_planner parameters. What computer are you using as onboard computer

2020-09-13 02:14:49 -0500 commented question rosrun rosserial_python serial_node.py /dev/ttyACM0 [INFO] [1599634137.432223]: ROS Serial Python Node [INFO] [1599634137.435236]: Connecting to /dev/ttyACM0 at 57600 baud

AFAIK, rosserial_python is the best package for the job. Are you sure the port name is /dev/ttyACM0?

2020-09-13 02:13:21 -0500 commented answer Problem with TF Tree in RPLidar Hector SLAM and Navigation

Hey, I did get it to work. What issue are you exactly facing? Would be happy to help you :)

2020-09-10 02:16:40 -0500 commented question rosrun rosserial_python serial_node.py /dev/ttyACM0 [INFO] [1599634137.432223]: ROS Serial Python Node [INFO] [1599634137.435236]: Connecting to /dev/ttyACM0 at 57600 baud

Does your arduino work properly well with, say, a simple blink program which doesn't involve ROS libraries at all? Are y

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2020-09-04 09:59:16 -0500 answered a question Preparing ROS Robot for Release

This is what you are looking for: https://kyrofa.com/posts/from-ros-prototype-to-production-on-ubuntu-core-1-5

2020-09-04 09:45:37 -0500 edited question Effects of laser not publishing messages sometimes on mapping?

Effects of laser not publishing messages sometimes on mapping? Hi, I'm using a 2D 360degree laser scanner which publishe

2020-09-04 09:43:57 -0500 edited question Effects of laser not publishing messages sometimes on mapping?

Effects of laser not publishing messages sometimes on mapping? Hi, I'm using a 2D 360degree laser scanner which publishe

2020-09-04 09:43:10 -0500 asked a question Effects of laser not publishing messages sometimes on mapping?

Effects of laser not publishing messages sometimes on mapping? Hi, I'm using a 2D 360degree laser scanner which publishe

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2020-08-29 03:08:18 -0500 commented question Hector_mapping Transform fails after some time

I also came across this wonderful page: http://wiki.ros.org/tf/Errors%20explained and I think the problem is similar to

2020-08-28 09:27:29 -0500 asked a question Hector_mapping Transform fails after some time

Hector_mapping Transform fails after some time Friends, I'm facing an issue with hector_mapping. The mapping starts fine

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2020-08-24 08:40:59 -0500 commented answer Is ROS using velocity motion model or odometry motion model?

Thanks, super useful! I also found on page 133 that odometry models are used for localization/mapping, while velocity mo

2020-08-24 08:38:02 -0500 commented answer How to find source of TF_NAN_INPUT error

Hi @jayess I'm facing similar issue while running hector_mapping: https://answers.ros.org/question/360033/hector-mapping

2020-08-24 08:35:25 -0500 commented answer How to solve TF_NAN_INPUT

I'm facing this issue while running hector_mapping: https://answers.ros.org/question/360033/hector-mapping-tf-issue-tf_n

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2020-08-20 13:00:17 -0500 asked a question hector mapping tf issue: TF_NAN_INPUT and TF_DENORMALIZED_QUATERNION

hector mapping tf issue: TF_NAN_INPUT and TF_DENORMALIZED_QUATERNION I'm facing very odd issues. While running hector_ma

2020-08-20 12:50:56 -0500 answered a question How to fix problem searchDir angle change too large

Something which recently happened to me, the issue turned out to be the LiDaR had become inaccurate. Replacing the old w

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2020-08-19 09:16:37 -0500 asked a question Is ROS using velocity motion model or odometry motion model?

Is ROS using velocity motion model or odometry motion model? Hi, I've been reading Probabilistic Robotics by Thrun et al

2020-08-13 11:41:26 -0500 answered a question How to get the wheel odometry

To get encoder ticks, you can connect the encoders to an Arduino, among many other ways. You will find a lot of help to

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2020-08-13 11:31:53 -0500 commented question Problem when I do source /opt/ros/melodic/setup.bash

Why don't you clone it to a workspace in home directory? It's better if you don't mess with /opt directory if you aren't

2020-08-13 11:28:17 -0500 answered a question How to tune dwa_local_planner parameters

First, read the wiki page for base local planner which is the dwa planner. If you want a deeper understanding, read Dyna

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2020-08-13 11:23:40 -0500 commented answer AMCL and ICP for localization - Any ICP Packages for Melodic?

I guess you already know this, but in case you don't: The accuracy of localization will not just depend on the package b

2020-08-13 11:20:13 -0500 commented question Frontier Exploration Parameters

Add link to the package you are referring to. Just by reading the parameter names, I'm guessing they are some setting so

2020-08-12 23:51:47 -0500 commented answer TF laser_frame is jump up and down flickering, each time i try to turn the map make a mess

No problem, we all make mistakes when we start. From my experience I would suggest you invest in encoders and IMU along

2020-08-12 12:23:29 -0500 edited answer TF laser_frame is jump up and down flickering, each time i try to turn the map make a mess

You will probably find information/solution regarding your problem faster if you just search about it on google followed

2020-08-12 12:21:52 -0500 answered a question TF laser_frame is jump up and down flickering, each time i try to turn the map make a mess

From your image, it seems you are using hector_mapping with default parameter values. This is a common result for the s

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2020-08-12 12:08:12 -0500 commented question How to solve MD5sum version error ?

The msg definitions might be different. Easiest way to check if what you get is what you expected is to do a rosmsg info

2020-08-12 12:08:00 -0500 commented question How to solve MD5sum version error ?

The msg definitions might be different. Easiest way to check if what you get is what you expected is to do a rosmsg info

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2020-07-14 08:22:42 -0500 commented answer What is the difference between min_vel_x, min_trans_vel and trans_stopped_vel?

This answered all my questions, thanks a lot David!

2020-07-14 08:22:03 -0500 marked best answer What is the difference between min_vel_x, min_trans_vel and trans_stopped_vel?

This might be a stupid question, but in the DWA planner, I've seen group of these three parameters which seems to be indicating the same thing to me.

My understanding: Minimum velocity in x direction is 0.1m/s let's say. Then by definition, that is also going to be the minimum translational velocity. For trans_stopped_vel, when I hover over the parameter in rqt_reconfigure, I see the definition on the lines of "Minimum velocity below which the robot is assumed to be not translating", which again seems to be saying the same thing to me.

If these three parameters actually mean the same thing, then it would be a waste to set them in thrice, so I'm assuming that there is a good reason they are not the same. Please enlighten me if that is the case and explain what each of them does.

Secondly, if I want the robot to be moving forward when possible and back off when it can't move forward but not prefer moving backwards otherwise, what values should I set these three parameters to?

Related third question: Is min_in_place_vel_theta parameter supported in kinetic and higher? I've seen some people mention it in previous answers, but I haven't noticed any difference by including/excluding it. And again, how are min_in_place_vel_theta, rot_stopped_vel and min_rot_vel different?

This group of parameters which seems trivially different to me appears for minimum rotational velocity, max velocities as well.

I'm happy to read the paper on DWA if it needs more information to understand, and would be happy if someone can point me to some literature for in depth understand, but I also think it would be beneficial for me and others to know at least a short summary to get it working with the DWA algorithm still being abstract, because I think that's the true advantage of ROS.

Robot details: I have a non-holonomic two wheeled differential drive robot, with DC geared motors(175rpm, 8.4kgfcm)

2020-07-14 08:21:33 -0500 commented answer Layered costmap performance

Thanks a lot for sharing the paper, helped me a lot to understand. So if I have laser scanner+sonar, what should be the

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2020-07-10 02:19:31 -0500 asked a question What is the difference between min_vel_x, min_trans_vel and trans_stopped_vel?

What is the difference between min_vel_x, min_trans_vel and trans_stopped_vel? This might be a stupid question, but in t