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1500 questions
6
votes
4 answers
What is the difference between RC motors for cars and helicopters?
I am working on a robot with focus on speed. At the moment I am looking for a suitable motor but it would help if I understood the difference between the various options.
To provide some background, I have not worked with RC model components before,…
danijar
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6
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1 answer
Do 6 motors require 6 individually-assigned batteries?
For the Dagu Wild Thumper 6 Wheeled platform, or any multiple motor system, do I really need 1 battery for each motor? Or should I just buy 2 for either side of the platform. In addition, for larger motors like the ones on this platform, how do I…
Monte Carlo
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6
votes
2 answers
Relationship between the velocity twist Jacobian and the spatial velocity Jacobian
While reading Kevin Lynch's "Modern Robotics" [1], I came across a fundamental question concerning the manipulator Jacobian.
Upon better reading and further cross-checking with Peter Corke's "Robotics, Vision and Control" [2], I have managed to only…
Henrique Ferrolho
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6
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5 answers
Why Euler Angle is set to be in ZYZ order?
We have 3 DOF for rotation in 3D space. So to describe an arbitrary rotation, we need to describe its 3 DOF. Euler angle does this by dividing a rotation in 3 steps, first rotate along the Z axis of the world frame ($z_0$), then rotate along Y axis…
hzh
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6
votes
4 answers
Multivariable PID controller
I'm making a robot that uses two DC motors to move, and has two distance sensors on its right side. I want to make a PID controller to control the angle of the robot (using a wall as reference) and also its distance to the wall.
I made a PID…
Iaka Noe
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6
votes
2 answers
How to speed up robotic arm?
I need my robotic arm to ring a desk bell. I one on the maplins site usb robotic arm.
It does seem very slow. What can I hack on it to boost the downwards and upwards speed. I need it hit the bell tip/platform quickly once or twice.
This is…
Piotr Kula
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6
votes
3 answers
PID and Kalman filters
Both PID and Kalman filters are used extensively in Robotics. I gather, Kalman filters for sensing and PID for control. What is the mathematical, statistical or other relationship between them?
pitosalas
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6
votes
3 answers
WHY are there no operating torque specifications on steppers?
I have been looking online for a while, and I cannot seem to find any steppers without any torque ratings. (Operating torque, not holding torque.) I even looked on hobby sites that usually have all the ratings, including Adafruit and Sparkfun. I…
Anonymous Penguin
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6
votes
1 answer
How can I get data from my kinect?
Whenever I try using openni_launch, it works normally, however, when I try viewing an image using the kinect's rgb or depth camera, or even recording a simple bagfile with data from the kinect, I am unable to see any picture and rosbag does not…
Y R
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6
votes
3 answers
Create 2 losing serial communication after toggling full to passive while charging
We are having an issue where after toggling the create 2 from passive to active, then waiting a few seconds and toggling back to passive while on the charger, all serial communication fails a certain percentage of the time. (Links to images of…
hcl337
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6
votes
1 answer
Motor and Ethernet shields together
I was wondering if it is possible to plug a motor shield on top of an Ethernet shield, even though the direction pins on the motor shield would be connected to the same pins as the spi bus. I was thinking that it would work if, in the coding, I…
Fearless
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6
votes
3 answers
How to get data from ArduPilot through Serial Port
I'm doing a project related to telemetry, and I want to make ArduPilot (programmed with ArduPlane 2.73) send through a serial port the sensors informations such as height, GPS position, etc.. I have tried to use ArduStation, but I could not change…
Alessandro Soares
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6
votes
1 answer
Technology behind Kiva Systems mobile robots
What kind of sensors and algorithms are the mobile robots of Kiva Systems equipped with?
hAcKnRoCk
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6
votes
3 answers
What does SE mean in robotics literature?
I've come across the abbreviation SE several times recently. I know it has to do with the pose of the robot, and the degrees of freedom. Most recently I found it on page 8 of this paper:
D. Kragic and H. I. Christensen, “Survey on visual servoing…
Preston Roy
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6
votes
1 answer
Poor accuracy of hand eye calibration when using vanilla Tsai's method
I’m working on the hand eye calibration for the robotic arm. I attached the camera near the tip of the robot (or end effector) and took around 40 pictures of an asymmetric circles pattern. I implemented the basic hand-eye calibration code (at the…
kangaroo
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