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1500 questions
3
votes
3 answers
Powering multicopter with multiple dedicated batteries
I am in the starting phase of building a fairly large octo-copter drone. I am currently thinking about the possibility of powering my octo-copter design using 4 separate batteries where each battery powers 2 motors each, in order to get around the…
RalleGAB
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3
votes
1 answer
Confusion of EKF equations
I read Probabilistic Robotics by Sebastian THRUN (online version). I also read http://ais.informatik.uni-freiburg.de/teaching/ws12/mapping/pdf/slam04-ekf-slam.pdf
Question1 :
What will be the dimension of Matrix $F(x,j)$ below? As per book its…
Encipher
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3
votes
2 answers
Alternatives to Finite State Machines (FSM's)?
In Udacity's Self-Driving Car Engineer online course, one instructor claims that "[Finite State Machines are] not necessarily the most common [approach for behavior planning] anymore, for reasons we will discuss later." I suppose the later…
xperroni
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3
votes
2 answers
Understanding MoveIt! and OMPL more deeply
I wanted to know the actual mathematics behind the path planners MoveIt! uses for manipulators from OMPL. I tried to look into source codes but couldn't get enough details.
I wish to know:
How cost function is implemented, i.e., how path cost is…
Saurabh Mirani
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3
votes
1 answer
What is the difference between a holonomic and an omnidirectional robot?
I have seen the usage of the term "omnidirectional" in robotics, but I have not found a (precise) definition.
In the chapter Omni-Directional Robots from the book "Embedded Robotics", it is stated:
In contrast, a holonomic or omnidirectional robot…
user10072
3
votes
2 answers
When and when not to use the Inertia tensor in Kinetic energy computing?
I'm trying to obtain the dynamic model of a 3D robot (academic problem), I have obtained the D-H table, the transformation matrix for each pair of links and the total transformation matrix. Now I'm struggling with computing the total Kinetic energy…
lu0
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3
votes
0 answers
How does marginalization of variables effect least squares SLAM energy function?
Consider a simple example of Bundle Adjustment where I have robot and landmark poses $x = \left[ x_p \text{ } x_m\right]^T$ and measurements given by $z$, such that a simple factor graph can be generated with the nodes containing poses and edges…
quartzfun
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3
votes
1 answer
Are both of C++ and Python necessary in ROS
I'm a newbie on ROS and I'm trying to figure out how ROS works so I'm installing ROS from source.
I've found that most of ROS packages contains two kinds of codes: C++ and Python. For example, here is the architecture of src of the ROS package…
Yves
- 265
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3
votes
3 answers
How can I receive Genicam packets from a device in a docker container?
I installed a command line tool which accepts genicam packets from a device as input into a docker image. If I use the option --network host in the run command for the container the packets are received. If I use -p 3956:3956/udp to expose the…
thinwybk
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3
votes
1 answer
How can I measure latency in a CAN bus?
Given a CAN bus with one master and any number of motor drivers, is there a way to measure the time between sending a command from the master (e.g. a PC running ROS) and the execution of the said command (e.g. the motor starting to move)?
This…
mohsen
- 31
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3
votes
1 answer
Arduino RC Kids Ride-On car: wiring help needed
I am wiring up a kids ride-on toy (Powerwheels) to control both speed and steering with an Arduino. The ultimate goal is to have the Arduino take analog inputs from the driver (steering and acceleration) as well as digital inputs from a Radio…
DontPanic
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3
votes
2 answers
Accelerometer bias removal
I found a good explanation on how to remove accelerometer bias (when on flat table only one axis should show values, the other two should be 0). I've calculated S and B factors (page 3):
Record $B_x^{0g}$, $B_y^{0g}$, $B_z^{0g}$, $S_{xx}$,…
c0dehunter
- 265
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- 8
3
votes
2 answers
RViz: How to Visualize a Voxblox Mesh as a MarkerArray?
I am currently trying to run the test cow and lady dataset with Voxblox. The process appears to execute properly in the terminal, but I cannot view the mesh in RViz.
When I try to add the topic voxblox_node/mesh to RViz, the topic name is greyed…
Mepix
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3
votes
2 answers
Why do we need a marginalization in Bundle Adjustment?
A common practice in Bundle Adjustment is to reduce the state dimension by marginalizing structure or pose states to improve the optimization speed.
In case 3d points(structure) $\textbf{p}_i$ are marginalized out as follows, $\textbf{p}_i$ are…
Chanoh Park
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3
votes
1 answer
Can I "shape" the sound of words spoken by Pepper with Phonetic transcription?
I am using Aldebaran/Softbank Robotics Pepper with Choregraphe software. There are some loan words in my dialogs. When Pepper say these words they often don't sound natural.
e.g. the german word Demenz (eng: dementia) The first e is to long. I…
buhtz
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