Robotics Stack Exchange
Robotics Stack Exchange

Most Popular

more tags
1500 questions
4
votes
2 answers

How to calculate probability of particle survival for particle filter?

I'm trying to figure out a way that I can calculate the probability that a particle will survive the re-sampling step in the particle filter algorithm. For the simple case of multinomial re-sampling, I can assume that we can model the process like a…
Bar
  • 143
  • 3
4
votes
1 answer

Do mobile robots use variable transmissions?

I've built a simple robot that can move. I'm using brushless motors. I've realized that at slow speeds the motors pull a lot of current. I didn't understand the power / current / efficiency charts when I started. I see it in the charts, now,…
mrtidy
  • 43
  • 3
4
votes
1 answer

Why with the pseudo-inverse it is possible to invert the Jacobian matrix even in a singular configuration?

Consider the following situation: I have a robotic arm manipulator with all revolute joints, for example consider a 2R planar manipulator. We know that if we compute the direct kinematics of it, anf the from the direct kinematics we derive the…
J.D.
  • 479
  • 2
  • 14
4
votes
3 answers

Unable to read pushbutton press properly in Arduino

I am trying to use a push button in order to know and print number of time a push button is pressed using a counter.But everytime i press the button , counter get incremented to sometime 3 and sometime 5 and some time counter does start >100 and…
shailendra
  • 327
  • 2
  • 6
  • 14
4
votes
2 answers

Is it possible to track position using gyroscope and accelerometer without a magnetometer?

I'm looking for help on a project where I will be placing sensor data in 3D space using augmented reality. Most solutions I have found for finding position with an IMU involve the magnetometer, but for my implementation that will not work because I…
Jack Haehl
  • 41
  • 2
4
votes
2 answers

How to take prediction step in particle filter?

I am working on particle filter. I have studied it thoroughly, but stucked at one point during implementation. I have to implement it using MatLab. The issue is this that I am unable to implement the prediction step. As far as I know, it is…
TariqS
  • 51
  • 2
4
votes
1 answer

Motion planning with Gaussian Process Regression

I was recently introduced to Gaussian Process Regression (GPR). I read multiple papers regarding use cases of GPR in robotics, however, they were more or less very limited. Use case from the literature: There is a robot arm with 5 joints. The…
Joe
  • 324
  • 1
  • 10
4
votes
1 answer

Questions about Irobot Create

I'm interested in getting a Create for a project I'll be working on, and wanted some information about it from somebody that already has one: How much weight can it safely carry? I talked with Irobot's tech support and they told me the maximum is…
Orgrim
  • 143
  • 3
4
votes
2 answers

roslaunch not found

Running ROS melodic on Ubuntu 18.04 and I keep getting this error. $ roslaunch arm robot_spawn.launch Command 'roslaunch' not found, but can be installed with: sudo apt install python-roslaunch I was able to launch prior to this but decided to…
heretoinfinity
  • 305
  • 1
  • 5
  • 14
4
votes
2 answers

How can I calculate odometry given two poses?

I have the pose at times t - 1 and time t. We are given: that the the new pose, at time t, is $$x_{t - 1} = [0,0,pi/6]$$ $$x_{t} = [0.2,0.1,(11*pi)/60]$$ (Where the vectors are [x, y, theta] with respect to some world frame.) In my head, I have…
BigBen
  • 41
  • 2
4
votes
1 answer

Calculate covariance matrix from x,y,z data

In ROS I've recorded a bag file from a custom robot (in real world) that does not provide covariance matrix and I want to use /odom to feed an EKF, but covariance matrix is 0. How can I calculate it? Note: Covariance matrix is needed by EKF to…
Maysam
  • 345
  • 3
  • 11
4
votes
2 answers

What should be the ideal ratio for link lengths ( L1/ L2) of a 2 link manipuator robot with revolute joints?

I am working on making a CAD model of a two link robotic manipulator, with link lengths around 15-20 cm. I am unable to figure how to set their mutual ratio and I want to know whether there is some fixed, determined ratio on how to take these…
S Ganesh
  • 41
  • 2
4
votes
5 answers

Is it possible to run multiple loops at the same time? (Arduino)

I've got a code where I have a motor running back and forth and buttons connected to a scanner, when I press the buttons it causes the motor to stop and over rides it. I would like them to run parallel to each other so the codes don't interrupt…
hollander
  • 107
  • 1
  • 3
  • 6
4
votes
1 answer

Velocity description in Screw Motion Theory

As described in the book Modern Robotics by Frank C. Park the velocity of a reference frame can be described as : $$V_s = J_s(\theta)\dot{\theta}$$ $$V_b = J_b(\theta)\dot{\theta}$$ However in the definition of the spatial velocities $V_s$ and $V_b$…
Ricardo Mostalac
  • 41
  • 2
4
votes
1 answer

ROS AMCL does not need odometry data?

I'm reading amcl document on ROS Wiki. In its subscribed topics there is not odometry topic, why? It works only with laser? Subscribed Topics: (From ROS Wiki) scan (sensor_msgs/LaserScan) tf (tf/tfMessage) initialpose…
Maysam
  • 345
  • 3
  • 11
1 2 3
…
99 100