Robotics Stack Exchange
Robotics Stack Exchange

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1500 questions
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4 answers

What kind of sensor do I need for knowing that something is placed at a position?

I have a small device that's picking up small rocks from a pile and moving them to another place. Its a kind of crude way of trying to push the whole pile onto a bigger gear and hoping one of them is pushed to one of the spaces between gears and…
bogen
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Properly flashing the firmware on a Lego Mindstorms NXT

I am attempting to upload a custom firmware to a Lego Mindstorms NXT and am having issues. First of all, I'm attempting to use nxtOSEK, which would let me run C++ programs on it. The problem is, everytime I put it into firmware update mode, the…
erik
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How to know when a Li-Po battery is discharged?

I'm building a quadcopter and I've seen that a Li-Po battery must not be entirely discharged, otherwise it could damage it. How do you know when you have to stop your quadcopter or robot in order to prevent damages, since the voltage doesn't drop?…
mimipc
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1 answer

SLAM: Why use two cameras (stereo) if SLAM can be done using single camera (monocular)?

I am aware that algorithm for monocular SLAM is complex compared to stereo SLAM. But my question is if by any means it is possible to do SLAM using one camera why one should use two cameras to do the same thing?
vacky
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3 answers

What would be the best way to handle food grains?

I'm trying to handle food grains like rice, wheat in an automated way (to cook simple dishes). For this I have to transfer grain from a larger container to a weighing scale. I know I can use solenoid valves for liquids but all solid handling valves…
ivymike
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2 answers

At which stage should filtering be applied to the sensors data?

Shall I filter (kalman/lowpass) after getting the raw values from a sensor or after converting the raw values to a usable data? Does it matter? If so, why? Example: Filter after getting raw values from IMU or filter after converting raw values to…
user697
8
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1 answer

Increasing the rotation range of a servo motor

How do I increase the rotation range of a standard servo? Most servos have a rotation range of ~ 180 degrees. I would like to access the entire 360 degree range on the servo, partially because I would be attaching the servo's shaft to the robotic…
Naresh
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Building a balancing robot with differential drive

I've already built a two wheeled balancing robot using some continuous rotation servos and an accelerometer/gyroscope. I upgraded the servos to some geared DC motors with 8-bit encoders with the goal having the robot drive around while balancing. …
JDD
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2 answers

Connecting multiple different voltage servos to the same controller

I am using the Pololu Micro Serial Servo Controller connected to an Arduino and multiple other servos (4 total) to make a robot arm. Two of the four servos require 4-6 volts, while the other 2 require 7-10 volts, so I am planning on powering all…
EAKAE
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Quadcopter PID Algorithm

I'm trying to implement a PID control on my quadcopter using the Tiva C series microcontroller but I have trouble making the PID stabilize the system. While I was testing the PID, I noticed slow or weak response from PID controller (the quad shows…
Saeed Molaie
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7
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3 answers

What iRobot products support the open interface besides the iRobot Create?

I have read that certain iRobot products support or can be hacked to support something close to the open interace. There is even a book about hacking Roomba. What Robots have this capability?
Kirk Lennard
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3 answers

Why would a drone need a magnetometer? Are an accelerometer and a gyroscope not sufficient?

Why would a drone need a magnetometer? What would the drone do with this information? I think it would be to tell direction, but why would it need this if it has an accelerometer and a gyroscope?
tox123
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1 answer

6D localization with 6 lasers

I have to know where a multi-rotor is, in a rectangular room, via 6 lasers, 2 on each axis. The problem is like this: Inputs : Room : square => 10 meters by 10 meters 6 positions of the lasers : Fixed on the frame 6 orientations of the lasers :…
Alexis Paques
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7
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4 answers

Optimal location of the center of mass for an inverted pendulum

I'm building an inverted pendulum to be controlled by DC motors, but I've run across a conundrum. Personal life experience tells me that it's better to have a lower center of mass to maintain balance. On the other hand, the greater the moment of…
Paul
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7
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L293D won't turn motor backwards

My small robot has two motors controlled by an L293D and that is controlled via a Raspberry Pi. They will both go forwards but only one will go backwards. I've tried different motors and tried different sockets in the breadboard, no luck. Either…
Hamzah Malik
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