# All Questions

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### Programming a G-Code Interpreter

I want programme my very own G-Code generator for my final year electrical engineering project. I know that there are many open source G-Code generators out there, but I need a gcode generator which ...
12 views

### Arduino Lightsensor Blocking Code

I have a GY-31 Light sensor and I am trying to make a skittle sorting machine. There is a little wheel skittles can drop into then they are turn to 90 degrees read by the light sensor then dropped out ...
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### What middle-ware do you recommend for a swarm of AUVs?

Working with a swarm of robots, collaboration between the nodes is really important(either for the goal of simulation or real-word operation). Middle-wares are the frameworks for this special purpose. ...
24 views

### Choosing suitable simulator for a swarm of AUVs

Which of the following simulators is the best choice for simulating a swarm of AUVs working together to perform a mission? Please clarify your reason and if you know any better choice, I would greatly ...
24 views

### Roll, Pitch Calculation Problem!

My problem is that when i hold my sensors (MPU9150) so that +y axis is downward, and y axis is on the horizontal plane, i expect that pitch = 90 degree, and roll = 0 degree, but actually pitch = 90 ...
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### What happens when a brush-less motor stalls?

Ok apologies for those who think my questions are not direct enough as I got warned about this. I am really new to this and I will try to keep this one direct enough for the forum. For obvious ...
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### Wheels for a robot having 15-20 kg weight

What type of wheel material is preferable on wooden floor....I am using nylon wheels but they don't seem to have enough friction and grip.
33 views

### Real time operating system for robotics vision

I have robot vision system which consists of conveyor with encoder, two cameras (gigabit eth and usb) and simple illuminator. I need to trigger cameras and illuminator when encoder reaches position ...
23 views

### Continous rotation with cables

A motor needs to spin n*365 degrees. On top of the motor there are distance sensor which scan the room. I.e. lidar. What options do I have for implementing a continous rotation while having cables ...
17 views

### Is a simple range sensor described below sufficient to implement particle filter localization?

I am trying to implement a monte carlo localization/particle filter localization with a simple range sensor. The range sensor only sees in the direction the robot is heading and returns back any ...
36 views

### Controlling a 400W motor with 24V 16A batteries with an arduino board

Can I control a 400W motor with 24V 16A batteries with an Arduino board and a mosfet? What type of mosfet would I use?
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### Understanding a sliding mode controller for quadrotors

I'm really willing to understand and implement such a controller (sliding mode) for a quadrotor. I've found this interesting document explaining that topic. If you scroll down until page 381 (don't be ...
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### How to change the orientation of an object w.r.t a scene?

I am trying to localize an object in a point cloud using ROS, PCL. For that I capture the scene and model using Asus xtion pro sensor. I use RGBDSLAMv2 for capturing the model. Then I use ICP ...
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### A robotics computer with graphics card, lots of computation power, battery, no screen, no keyboard? [on hold]

I'm working on a robotics platform and we need an on-board Ubuntu machine to run ROS image recognition. Does anyone know of a good set of computer hardware that has NO screen NO keyboard Built-in ...
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### How to control PID Yaw

My yaw angle varies from -180 degree to 180 degree. ...
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### Computational geometry or pattern recognition for a specialization in robotics? [on hold]

My background: I am currently doing MS in computer science, I am planning to do Ph.D. in Robotics, I have decided thesis track for my M.S., so it will help for my Ph.D. admission. My question: I have ...
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### How does the “rated torque” for a gear relate to the maximum torque?

I have just sized the DC motors I want to use (corresponding to my robot and its intended applications - my figures include a 50% uncertainty factor to account for friction in reducers and other ...
27 views

### Selecting a gear reduction: torque vs speed

I have just sized the DC motors I want to use (corresponding to my robot and its intended applications - my figures include a 50% uncertainty factor to account for friction in reducers and other ...
11 views

### Stated power for a motor does not equal nominal voltage x current?

I have just sized the DC motors I want to use (corresponding to my robot and its intended applications - my figures include a 50% uncertainty factor to account for friction in reducers and other ...
26 views

### Choosing DC motor: max needed torque vs nominal torque

I have just sized the DC motors I want to use (corresponding to my robot and its intended applications - my figures include a 50% uncertainty factor to account for friction in reducers and other ...
27 views

### Is the nominal voltage of a motor the voltage to apply to the motor?

I have just sized the DC motors I want to use (corresponding to my robot and its intended applications - my figures include a 50% uncertainty factor to account for friction in reducers and other ...
36 views

### NAO motor model identification

I am trying to create a model for the NAO [robot]'s motors. The figure below shows the step response for the knee motor. Afaik the NAO internally uses a pid controller to control the motor. I have no ...
18 views

### Implementing a position control for UAV through a flight controller. Plant model is unknown

We are using Naza-M-Lite for our flight controller without GPS. The localization is obtained through our RGB-D camera sensor. We are able to teleoperate and even implement PID controllers for Roll, ...
33 views

### Choosing motor characteristics [duplicate]

I have just sized the DC motors I want to use (corresponding to my robot and its intended applications - my figures include a 50% uncertainty factor to account for friction in reducers and other ...
14 views

### Using i2c's SCL and GPIO pins as SDA

The beaglebone black which I work on has only 2 i2c busses. Say for some crazy reason, i need to use 8 i2c busses. I dont want to chain any of the devices. The idea is to have every device's SDA line ...
27 views

### Is the input of ESC really limited at 50 Hz and will the PID controllers work properly?

Based on the wiki page of ESC, the ESC generally accepts a nominal 50 Hz PWM servo input signal whose pulse width varies from 1 ms to 2 ms http://en.wikipedia.org/wiki/Electronic_speed_control For ...
33 views

### AHRS Algorithm Question

As far as i understand, AHRS use orientation reference vectors to detect orientation error. And we can use magnetometer to correct yaw drift. But i see from my ak895 magnetometer that the data is not ...
13 views

### Comparing cordless driller motors with Dremel-type motors [on hold]

How is it that the small drillers (such as the Dremel and similar) can achieve such high rpm and torque from such a small motor when compared to a cordless drill motor? I know one difference is that ...
20 views

### RPM of cordless driller motors [on hold]

What are the typical speeds in rpm of a 7.2v, 12v, 14v and 18v cordless driller motors with and without the gearbox attached? Is it torque or maximum rpm that varies as the voltage increases from ...
32 views

### RNN instead of a PID controller

I am building a drone using the raspberry pi and I am using 6*PID controllers to control the speed and the value for each angle, can I use a recurrent neural network (RNN) or other neural network to ...
19 views

I bought 2 brushed motor controllers from China for my hobby-weight battle robot (http://www.banggood.com/ESC-Brushed-Speed-Controller-For-RC-Car-Truck-Boat-320A-7_2V-16V-p-915276.html). These are ...
20 views

### Changing tank drive (differential) mode to single joystick drive mode

I bought 2 brushed motor controllers from China to use within my hobby-weight battle robot (http://www.banggood.com/ESC-Brushed-Speed-Controller-For-RC-Car-Truck-Boat-320A-7_2V-16V-p-915276.html). ...
10 views

### Motor controller calibration

I bought 2 brushed motor controllers from China to use with my hobby-weight battle robot (http://www.banggood.com/ESC-Brushed-Speed-Controller-For-RC-Car-Truck-Boat-320A-7_2V-16V-p-915276.html). ...
52 views

### Proportional controller error doesn't approach zero

I'm reading this pdf. The dynamic equation of one arm is provided which is $$l \ddot{\theta} + d \dot{\theta} + mgL sin(\theta) = \tau$$ where $\theta$ : joint variable. $\tau$ : joint torque ...
24 views

### arduino connect to laptop over rosserial gives errno111

I'm building a robot and it's currently in it's early stages, currently I'm setting up ultrasonic sensors and it worked fine yesterday but today when I run the ...
23 views

### Probabilistic Velocity Obstacles

I have been working with the Velocity Obstacles concept. Recently, I came across a probabilistic extension of this and couldn't understand the inner workings. Source: Recursive Probabilistic ...
20 views

### Scan Matching finds right rotation but false translation

I'm currently developing a SLAM software on a robot, and I tried the Scan Matching algorithm to solve the odometry problem. I read this article : Metric-Based Iterative Closest Point Scan Matching ...
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### gazebo import robot gives error

I'm trying to import the tutorial robot given at this link However this gives the following error: ...
62 views

### Power switch and common ground on a battle robot

I am constructing a 5.44Kg Hobby-weight battle robot and one of the safety rules is that the robot must have a power switch that turns off power to the motors (and weapon). The robot has three ...
46 views

### Image processing in bright lights

We are working on a project which requires us to detect and hit a ball. We are trying to accomplish the task by detecting the position of ball by processing the input from a camera. The problem is ...
69 views

### tracking robot in a room

I'm trying to track a simple robot (e.g. arduino, raspberry pi, even toys) in a room using fixed location kinect sensor(s) and cameras at different parts of the room. How might one usually use to do ...
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### how to power extra usb devices for beaglebone black

I'm building a robot that uses a beaglebone black, however I have several different usb devices that I want to connect to it (microphone, usb sound device and some other things). Now I have heard that ...
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### Which is more useful? Instantaneous rate of change of displacement or Average rate of change of displacement?

Instantaneous rate of change of displacement is given by, v(t) = (s(t + dt) - s(t))/dt, where dt tends to 0 while average rate of change of displacement is given ...
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### Learning Materials for Beginners in Robotics and Quadrocopters

I am a web developer. I am fascinated by Quadrocopters and i am trying to learn how to build one and basically i am trying to jump into robotics fields. I don't have much electric circuit and ...
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### Sending a smartphone's GPS wireless

I'm building camera device which is able to take pictures of paragliders in mid air. To let the camera know where the glider is I thought about using GPS data from the pilot's smartphone. My ...
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### How to find the height of a rock with a rover?

So, I am designing a rover that will navigate to a rock, and then calculate the height of the rock. Currently, my team's design involves using an ultrasonic rangefinder and lots of math. I was ...
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### Parameter $r$ of Denavit-Hartenberg

By watching this video which explains how to calculate the classic Denavit–Hartenberg parameters of a kinematic chain, I was left with the impression that the parameter $r_i$ (or $a_i$) will always be ...
90 views

### Build a ROS robot with SLAM without laser

I've build a simple wheeled robot based on two continuous servos, controlled by Raspberry Pi running ROS-groovy, with a smart phone mounted on top to provide additional sensors. I'd like to situate ...