Robotics Stack Exchange
Robotics Stack Exchange

Most Popular

more tags
1500 questions
5
votes
1 answer

Transducer for underwater applications (passive sonar)

I'm kicking around the idea of building a small passive sonar for an autonomous submarine. I've looked through the net for parts and finding a good transducer for converting the sound underwater into an electrical impulse. After looking at parts I…
mj_
  • 165
  • 4
5
votes
2 answers

ROS Theoretical Question - How does work properly a node

I'm new at ROS and I'm trying to figure out how does the node works with a pyton/C++ code. I have two codes for the same situation: Use a Xbox Controller to move the turtle in turtlesim FIRST - Using class python and a while as a…
Kaike Wesley Reis
  • 51
  • 4
5
votes
3 answers

Robotics Trends

Robotics has always been one of those engineering fields which has promised so much, but is taking a long time to deliver all the things that people imagine. When someone asks: "How long before we have [X] type of robots?" Are there any resources we…
Rocketmagnet
  • 6,457
  • 5
  • 29
  • 54
5
votes
1 answer

What frame of reference is used during Visual Servoing?

I'm new to the whole visual servoing area. I'm now reading the tutorial Visual Servo Control Part I: Basic Approaches" and I don't understand something fundamental - what information is available to the robot? Is the 3D location of the tracked…
Ofer
  • 161
  • 5
5
votes
1 answer

Gears modeling in Google SketchUp and SketchyPhisics

I'm trying to make differential in Google SketchUp using this tutorial http://support.ponoko.com/entries/21249896-Gears-and-Joints-with-SketchUp-Sketchy-Physics for gears modeling. But I have problem: gears don't collide with any objects (and other…
Robotex
  • 185
  • 1
  • 2
5
votes
1 answer

Wrong forward-kinematic after calculating from DH-parameters

I'm working on an exercise about DH-parameters for my robotics course in university and I ran into a problem, because my solution is different from the one given by my professor. I calculated the DH-parameters $\theta=\theta_1-90˚, d=20m, a=0,…
Max
  • 153
  • 3
5
votes
1 answer

Actuator design. plausible?

So i got this idea waay back when i was in highschool as a kind of electromagnetic analogue to a biological muscle. it is basically a long stack of thin electromagnets connected in parallel. . when current is applied gaps between electromagnets…
Andrew Butenko
  • 165
  • 4
5
votes
1 answer

Any globally unique signature in Ardupilot hardware, or Arduino in general?

I have several APM 2.5 boards and need to identify them based on some globally unique hardware signature that does not change with programming. Arduinos and atmel AVR chips in general do not have (also this thread) an accessible serial…
foobarbecue
  • 643
  • 5
  • 15
5
votes
4 answers

Off-the-shelf micro fluid dispenser

Need a way to dispense micro liter amounts of water (lets say 1-10ul). Only thing I've found is piezoelectric dispensers and they are >$100. Any suggestions? I can build, but preferably would be an off-the-shelf component.
Chris
  • 59
  • 2
5
votes
1 answer

Wind force impact on torque mechanical arm

I've got an arm attached to a shaft. The arms dimensions are 40x5 inches the arm weights about 10 lbs. If I have a wind acting on the side of the arm, how would I translate the wind force into torque on the shaft? To give some more information, I'm…
Mattias
  • 151
  • 1
5
votes
3 answers

Moldable rubber for "feet"

I’m trying to inject some kind of rubber around an aluminum strut to form “feet” for a robot. I’ve already milled the mold, but I’m having trouble finding an inexpensive and readily available rubber compound that will cure without exposure to air.…
Chris
  • 1,005
  • 1
  • 10
  • 17
5
votes
1 answer

Noisy magnetometer data

I’m looking to develop an AHRS for which I’m using a magnetometer to correct for heading errors. I wanted to check that the magnetometer I'm using is functioning to the level of accuracy (+- 1 degree) that I’m aiming for, before doing any other…
Joe
  • 69
  • 6
5
votes
1 answer

classify if two adjacent surfaces belong to same object

I have a box (cuboid) lying on floor or table. So there are 6 surfaces of the box and 1 surface of the floor. If I take each pair of surface such that the surfaces are "adjacent" to each other, I get two kind of pairings: 1) two surfaces of the box:…
Swagatika
  • 251
  • 1
  • 5
5
votes
2 answers

Inconsistent results between Simulink derivative model and tf for PD controller

I'm designing a PD controller so that the response due to unit step should exhibit an overshoot of 20% and steady-state error less 0.01. I've computed the parameters Kp and Kd and double-checked the result based on root locus design approach. This…
CroCo
  • 2,453
  • 1
  • 17
  • 40
5
votes
2 answers

Making a robot go in a straight rate - sampling rate for motor PID

I'm trying to build a robot/rover based on Raspberry Pi 3 At the moment I'm straggling with a basic driving in a straight line. I'm in a process of tuning my PID code andI'm not sure what sampling rate should I choose. These are the specs of the…
Leonti
  • 173
  • 4
1 2 3
…
99 100