Robotics Stack Exchange
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Question about Lens distortion

Suppose I have a 240x180 camera with the following distortion co-efficients, $$k_1 = -0.138592767408$$ $$k_2=0.0933736664192$$ $$k_3=0.0$$ $$p_1=k_4=-0.000335586987532$$ $$p_2=k_5=0.000173720158228$$ The camera center is given to be $$u_0 =…
Ashish Rao M
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Trigger two usb cameras at the same time

I'm studyng stereo cameras, and I want to build one. I searched a lot in internet, and the opinions are quite different about this topic. Basically, my question is: Can I synchronize two usb cameras triggering them together, shooting at the same…
Giuseppe Sensolini
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Best way to estimate velocity of motor with encoder

I'm designing a PMSM controller with the motor has an optical encoder, so I can get position information from the motor. But how to measure the velocity of the motor. Now, my design is to calculate the difference, then add a low pass filter to…
Hyz Yuzhou
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1 answer

SEIF ,online version of Graph slam create doubt in Motion Update state

I have a thesis work about Graph Slam The GraphSLAM Algorithm with Applications to Large-Scale Mapping of Urban Structures I try to implement it with the help of this paper but during the implementation stage I came to know that it requires a huge…
Encipher
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How reliable are IMUs for a long usage (6 hours) rotation (only) tracking?

I know they are bad for positional tracking and drift from actual position over time but would like to know what is the situation with rotation only. I know Oculus DK1 used ordinary off-the-shelf cheap IMUs for rotation tracking of the user's head,…
Mark Legault
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3
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Meaning of a negative step response with quaternion

It's not technically robotics but: I've been trying to reproduce in Simulink a spacecraft attitude simulation using quaternions, and the kinematics and dynamics seem to work fine, however I'm having a bit of trouble with the controller. I followed…
PaoloH
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3
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Denavit-Hartenberg convention in practice

How are the coordinate frames and D-H parameters determined in industry? Does one use the CAD drawing of the arm or physically take measurements of the actual arm?
Marcio de Queiroz
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1 answer

Finding Joint speeds for each joint of a 6DOF arm (UR10) using the Inverse Jacobian

Background: I have access to a UR-10, 6DOF robotic arm through my school (I'm very new to robotics). I know the desired set of linear speeds that I want in the x,y, z-direction in terms of the end effector ([x,y,z,rx =0, ry,=0, rz =0]). Using an…
NoviceCoder
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Multiple View Triangulation method used by COLMAP

I'm looking at how COLMAP does multi-view triangulation. I can't work out what this function is doing. I can't find any formulas which look similar. The input "proj_matricies" come from pose data, the "points" are from the mono camera measurements.…
B_N
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Which controller to use for custom servo?

I am trying to build a microcontroller based higher payload version of a servo motor using geared induction motor with VFD as a control device. For this purpose I have selected a 1HP motor running at 1800RPM which is geared down to 30RPM. The…
Supreeth
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ROS: Human to Robot Mapping (Baxter)

I'm having some difficulties understanding the concept of teleoperation in ROS so hoping someone can clear some things up. I am trying to control a Baxter robot (in simulation) using a HTC Vive device. I have a node (publisher) which successfully…
Kite
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3
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1 answer

MSP (Multiwii Serial Protocol) receiving data with pyMultiWii issue

I want to get telemetry data from my flight controller (Matek F405-CTR) and send control commands to it via MSP protocol. I've already configured UART3 port on Matek in Inav configurator (look at pic). Then I connected usb-serial converter (CP2102)…
mr.incredible
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1 answer

How to design a differential steering mechanism?

I want to give my robot a differential mechanism for the system of turning and steering. Considering the case of turning a right-angled corner, the robot will achieve this by following a gradual circular arc through the intersection while…
Ghost
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Is ROS 2 due to replace ROS 1?

I have read ROS 2 document and they did not give many clues on the subject. Does anybody have more insight on the subject?
arennuit
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measuring gears for servo motors

I'm quite new to mechanical engineering and not familiar with gears and motors. A few days ago, I bought a second-hand GWS servo motor for my project, and it didn't include gears. Can someone help me understand the correct measurement of my motor so…
user1735120
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