Robotics Stack Exchange
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1500 questions
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2 answers

Brush-less motor specs vs efficiency for multi-copters

I am looking for some figures surrounding the specs of brushless motors and their relative efficiency (in power usage terms) for multi-copter use. There are 4 basic specs for motors themselves: - Motor width (EG 28mm) - Motor height (EG 30mm) -…
Digital Lightcraft
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Is there a working implementation of "Navigation Among Movable Obstacles" for a bi-pedal robot?

I would like to have a better understanding of work in the field of "Navigation Among Movable Obstacles". I started off with Michael Stilman's thesis under James Kuffner, but that has not yet sated my appetite. I am currently trying to simulate a…
Naresh
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Ensemble Kalman Filter SLAM

I know that there is an extended kalman filter approach to simultaneous localization and mapping. I'm curious if there is a SLAM algorithm that exploits the ensemble kalman filter. A citation would be great, if at all possible.
Paul
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Euler Angles from 9DOF IMU

Using the Adafruit 9DoF module I Need to convert the Accel + Magneto + Gyro into Euler Angles for a motion capture application. Any hints on where to start? Managed to get X,Y,Z when the IMU is facing upward but when that orientation changes the…
user2967920
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2 answers

computer vision using the FREAK local features descriptor - why overlapping fields?

I am currently studying the FREAK descriptor and I read the article published by its designers. It states that the aim was to mimic the retinal topology, and one of the advantages that could be gained is the fact that retinal receptive fields…
S.E.K.
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2 answers

Is there a rule of thumb for actuator torque overhead?

When installing a servo or other actuator, I measure the force needed to perform whatever action is needed and find an actuator that can generate more than the necessary force. However, I recently wondered if there's a rule of thumb or guideline for…
JYelton
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3 answers

PID Integration over not constant dt (∆time)

Is integration over not constant dt (∆time) a possible thing? Let's say you have a PID loop with differentiating frequency, can the integral part of it still work? (Assuming you know the dt from the last iteration) Could I just use a variable dt…
Dan Barzilay
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3 answers

Questions about quadcopter and radio controller

I have not bought any parts yet, but I am making my own quadcopter. I have done the research and know all about the parts that I need, but many guides are sponsored and cost thousand(s) of euros/dollars while not explaining things entirely…
AlexanderK47
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3 answers

restricting range of motion with complex constraints

I am looking for a way to restrict a robot's range of motion, using complex constraints such as not tearing of a cable attached to the robot. Take an articulated 6-axis robot arm as shown below, with attached cable (red), fixed at points X (before…
HugoRune
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Is subsumption architecture still an active area of research?

I am interested in learning more about subsumption architecture. I have read a number of books that talk about the idea but none of them go into great detail. I have also read a fair number of Dr. Brooks papers on the topic however he hasn't…
DaemonMaker
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Tendon longevity

I am thinking of developing a tendon driven robot manipulator for an industrial application that requires a high level of reliability. However, I am aware that tendons in a robot are prone to wear and tear, and failure. How can I go about selecting…
Rocketmagnet
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One of the best ways to numerically integrate the velocity?

I need to get position $x$ from integrating velocity $v$. One could use 1st order Euler integration as $x_{t+1} = x_t + \delta * v_t.$ However, doing so leads to errors proportional to sampling time $\delta$. Do you know any more accurate solution…
Courier
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6
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3 answers

Are there any problems with a variable frequency PID?

I am working on a quadrotor and am trying to solve the problems described here. In attempts to bring the refresh rate to 100 Hz, I did an analysis of the functions and most of the time 35+ ms is being taken by the RC receiver input function. To…
asheeshr
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6
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4 answers

How frequently should a PID controller update?

I am developing a quadcopter platform on which will be extended over the next year. The project can be found on Github. Currently, we are using an Arduino Uno R3 as the flight management module. At present, I am tuning the PID loops. The PID…
asheeshr
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6
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1 answer

What are some good cheap, silent, motors for mannequin robots and what kind of controller should I use?

What are some good cheap, silent, motors for mannequin robots and what kind of controller should I use? I'm creating mannequin robots that require 24 motors: 2 neck, 4 shoulder, 2 elbow, 4 wrist, 2 waist, 4 hip, 2 knee and 4 ankle motors. The…
Zxen
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