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2021-10-19 09:56:13 -0500 edited question Quaternion Vector Conversation

Quaternion Conversation Hi, I want to compute the orientation of the given translate vector. I only find the conversatio

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2021-10-19 09:55:46 -0500 asked a question Quaternion Vector Conversation

Quaternion Conversation Hi, I want to compute the orientation of the given translate vector. I only find the conversatio

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2021-10-07 00:59:11 -0500 commented answer Common Map Creation method

Hi, may I ask which robot base and sensors you are using for rtabmap? Because I am also using the rtabmap, it is indee

2021-10-07 00:57:58 -0500 commented answer Common Map Creation method

Hi, may I ask which robot base and sensors you are using for rtabmap? Because I am also using the rtabmap, it is indee

2021-10-06 04:29:25 -0500 commented answer Common Map Creation method

Hi, if you are interested in how to use it. This is the tutorial I follow. Hope you can share your test result of the pe

2021-10-05 02:30:04 -0500 asked a question Common Map Creation method

Common Map Creation method Hi, Originally when I tried to create a 2D-Occupancy map, I do it manually or use the rrt_ex

2021-09-30 01:17:13 -0500 marked best answer Rosserial Publish method

Hi, I am using rosserial packge for the external sensors. When I dig into the tutorial, I found that there are two types of publishing. 1. publish raw data std_msg (Temperature) 2. publish correct format of rostopic with sensor_msg class (IR Ranger)

The first method will have a higher publish rate naturally since there is no other task perform upon. However, the timestamp will have a little bit of delay since it is generated by the computer side. In my case, it is IMU with 50 hz sampling rate. The second one will have better timestamp accuracy. However, due to the extra process I only get 10 hz in this case.

I wonder what is the standard method to publish embed sensor with rosserial package. The first one or the second one?

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2021-09-24 11:45:52 -0500 commented question Rosserial Publish method

Yeah, you are right, it didn't strike me that is the reason. But in that case, wouldn't the rosserial sensor_msg class

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2021-09-24 05:48:04 -0500 asked a question Rosserial Serialization

Rosserial Serialization Hi, I am using rosserial packge for the external sensors. When I dig into the tutorial, I found

2021-09-24 05:42:11 -0500 asked a question Rosserial Publish method

Rosserial Publish method Hi, I am using rosserial packge for the external sensors. When I dig into the tutorial, I found

2021-09-24 05:30:12 -0500 marked best answer 3D mapping Cliff Detection

Hi, I am using rtabmap in my project with Velodyne VLP-16 sensor so that the ground can be identified by the slam algorithm. As mention here that if I want to detect the cliff robustly, then it requires 3D mapping since it can provide groundtracking.

In reality, the stair should be 3 meters in front of the robot. However, in my mapping, as you can see the following.

image

There is no cliff identified in the map since the lidar didn't san the surface of the stair due to the scanning angle.

To my understanding, the meaning of groudtracking is that the ground will be identified and extend and if the lidar sensor failed to have scan return the cliff will then be identified.

Did I misunderstand anything or misconfig anything, if so please do correct me. Thanks.

Best regards, Jack Lu

2021-09-24 03:57:24 -0500 commented question Rosserial Serialize Example

Thank you for your fast comment. I think I will start another post. The question is a little bit off-track. I did alread

2021-09-23 23:32:26 -0500 edited question Rosserial Serialize Example

Rosserial Serialize Example Hi, I am using rosserial package to acquire the customized sensor data from the Arduino boar

2021-09-23 23:31:43 -0500 commented question Rosserial Serialize Example

Ok, thank you, I will dig in, and sorry for asking multiple questions within the same post.

2021-09-23 03:45:41 -0500 asked a question Rosserial Serialize Example

Rosserial Serialize Example Hi, I am using rosserial package to acquire the customized sensor data from the Arduino boar

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2021-08-24 23:50:09 -0500 commented answer How to create a costmap layer to avoid downward stairs

Hi, I tried to tackle the cliff with the 3D mapping. In my case I use rtabmapping, but it seems that if there is no poin

2021-08-24 03:36:15 -0500 asked a question 3D mapping Cliff Detection

3D mapping Cliff Detection Hi, I am using rtabmap in my project with Velodyne VLP-16 sensor so that the ground can be id

2021-08-10 08:54:07 -0500 asked a question Turtlebot Dual Camera

Turtlebot Dual Camera Hi, I am using turtlebot2 with two cameras. One is atra, the other is one is kinetic. To make ena

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2021-07-27 01:50:22 -0500 marked best answer Rtabmap Object Obstacle Problem

Hi, I want to setup my turtlebot for Full autonomous Navigation with rtabmap. The first problem I encounter is that 3D irregular shape objects, such as chairs. In this case, if I use scan topic the chair can only be identified with a certain height.

The second problem I encounter is that cliff, since the cliff is 3D it is impossible to identify.

Both of them can be resolved with scan_cloud enable. However, in this case, all the movable objects, such as chairs will be drawn as obstacles in the projection map.

Here the demo of the official video demonstrates that with scan and depth information they can map out the 2-D environment and 3-D objects at the same time.

I am wondering the following: 1. How can I avoid the 3-D object in the above video case since it is empty for the position? 2. How can I avoid the cliff with depth information?

Thanks in advance.

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2021-07-27 01:50:20 -0500 commented answer Rtabmap Object Obstacle Problem

Thank you for the answer. It helps a lot.

2021-07-23 01:13:47 -0500 commented answer Rtabmap Object Obstacle Problem

Hi, thanks for your fast reply. And I know this might be stupid to ask but where can I define safe since the turtlebot u

2021-07-23 01:09:44 -0500 marked best answer The relationship of earth frame and map frame

I follow the instruction of REP:105. As it mentioned to have the map frame corrected by the earth frame. So I use imu_filter_madgwick with 9-axis sensor to produce the absolute orientation of the earth and map. Then, use the function provided by the same package to produce the earth and map correction in /tf tree.

However, what I got is the following. the mapping will constant rotation of the map. Hence the rotational mapping result. Mapping in RVIZ

This is my /tf tree. TF Tree

There must be some misunderstanding for me. Please help clarify it. Thanks in advance.

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2021-07-22 10:14:16 -0500 asked a question Rtabmap Object Obstacle Problem

Rtabmap Object Obstacle Problem Hi, I want to setup my turtlebot for Full autonomous Navigation with rtabmap. The first

2021-07-13 01:58:38 -0500 commented answer The relationship of earth frame and map frame

I got it. Thank you for your time and the detailed explanation.

2021-07-12 07:22:39 -0500 commented answer The relationship of earth frame and map frame

I think it's more close to 2. Since I want to map the environment as a global map. With the information given by you, I

2021-07-12 03:15:19 -0500 commented answer The relationship of earth frame and map frame

Thank you for the clarification. In that case, wouldn't the earth frame a little bit ineffective in most cases since i

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2021-07-09 04:03:09 -0500 commented answer The relationship of earth frame and map frame

Hi, thank you for your reply. You point out my blind spot about the relationship of earth->map frame. It should be co

2021-07-08 10:59:59 -0500 asked a question The relationship of earth frame and map frame

The relationship of earth frame and map frame I follow the instruction of REP:105. As it mentioned to have the map fram

2021-01-19 05:26:46 -0500 asked a question Past Trajectory Extraction along with Time

Past Trajectory Extraction along with Time HI, I want to extract the pose of robots and time. However, if I record the

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