0
votes
0answers
9 views

Choosing motor characteristics

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 ...
1
vote
1answer
8 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 ...
1
vote
1answer
23 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 ...
0
votes
0answers
15 views

choosing a microcontroller [on hold]

I want to build a line follower robot which will solve a specific problem of solving a grid. I want it to be fast in terms of its mobility and and its processing speed,means less time for data to ...
0
votes
0answers
28 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 ...
0
votes
0answers
11 views

Comparing cordless driller motors with Dremel-type motors

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 ...
-1
votes
1answer
17 views

RPM of cordless driller motors

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 ...
0
votes
0answers
22 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 ...
0
votes
1answer
14 views

Risk of overloading motor controller

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 ...
1
vote
2answers
16 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). ...
0
votes
1answer
8 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). ...
1
vote
1answer
22 views

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 ...
0
votes
0answers
16 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 ...
1
vote
0answers
17 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 ...
1
vote
0answers
18 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 ...
0
votes
1answer
10 views

gazebo import robot gives error

I'm trying to import the tutorial robot given at this link However this gives the following error: ...
1
vote
2answers
48 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 ...
1
vote
2answers
38 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 ...
1
vote
1answer
52 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 ...
3
votes
2answers
66 views

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 ...
0
votes
1answer
23 views

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 ...
1
vote
1answer
49 views

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 ...
0
votes
1answer
20 views

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 ...
1
vote
1answer
31 views

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 ...
2
votes
1answer
21 views

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 ...
3
votes
1answer
82 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 ...
1
vote
0answers
41 views

PID Control Tuning [duplicate]

Im currently designing a robot for my undergraduate project. One of the task of this robot is to follow the wall. For the purpose I'm using a PID control system, where the reference is given from a ...
1
vote
0answers
18 views

Survey for Local Navigation [on hold]

I was wondering if there was a good book or paper that surveys current techniques in local navigation? The earliest one I could find was from 2005 and I was hoping to find something more recent. I ...
1
vote
1answer
16 views

How do I get this transformation matrix?

I've just started taking a robotics course and I am having a little problem. I need to rotate the $O_i-1$ coordinate system into a position, where $X_i-1$ will be parallel with $X_i$. The ...
1
vote
0answers
10 views

Numerical-Example for Paden-Kahan subproblems?

I am writing a kinematics library in Go as part of my final year project. I am working with Product of Exponentials method and have successfully implemented the Forward Kinematics part of this. I need ...
0
votes
1answer
28 views

Tilt-Compensated Compass Problem MPU9150 [on hold]

I am implementing a tilt-compensated eCompass, using MPU9150's accelerometer and magnetometer. My steps: Reading magnetometer's data. Hard-iron compensation. Normalize data after Hard-iron ...
0
votes
1answer
12 views

Wheeled Robot Motion Primitives: Is throttling forward and crab motion considered as one?

I am simulating a wheeled robot of six-wheels and can be independently steered, like MER-Opportunity. The wheeled robot can perform throttling forward, ...
1
vote
2answers
30 views

Can I make an automatically-parking robot car with IR sensor?

It would be easy to understand if you imagine a robotic vacuum cleaner. (For some models) It goes back to a specific place automatically to recharge. Like this, I want to make a robot which ...
0
votes
1answer
21 views

ros node does not seem to do anything

I have the following code for the ros turtlesim: ...
1
vote
1answer
9 views

Recursive Tree Representation for Multi Agent Robots?

I have been going through a code base for multi agent motion planning. And I came across a recursive tree building algorithm for the agents. I haven't been able to figure out the algorithm. Does ...
0
votes
1answer
23 views

biped walking using Genetic Algorithm

I am working on a project but I lack advanced programming knowledge, especially about genetic algorithms. I am developing a prototype using WEBOTS 7.4.3 for the simulation. The project is to use ...
1
vote
0answers
11 views

Hokuyo URG-04LX-UG01 and Mac compatibility issues

I've got my hands on this laser range scanner but seem to have some problem receiving any output from it. I can't find any guide on how to set it up on the internet, so I was wondering if it is even ...
4
votes
1answer
14 views

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: - ...
1
vote
1answer
33 views

How to convert PID outputs to appropriate motor speeds for a quad copter

I am building an autonomous robot using PID control algorithm. So, far I have implemented PID using online resources/references. I am testing for stabilizing an axis of the quad copter. However, I am ...
0
votes
0answers
24 views

Motor recommendation for spinning disk weapon

Any suggestions for an inexpensive but effective motor for a spinning disk weapon (vertical spin) for a hobby-weight (5.44Kg) battle robot please? I have no experience at all with brush-less motors ...
2
votes
1answer
31 views

Detect road surface in a traffic scene point cloud

I want to analyze a traffic scene. My source data is a point cloud like this one (see images at the bottom of that post). I want to be able to detect objects that are on the road (cars, cyclists ...
1
vote
1answer
31 views

Motor for weapon for Hobbyweight

I am currently building a hobby-weight (5.44kg) robot. The weapon will be a vertical spinning disk at the front. It will probably be a commercial one from the hardware store or I could maybe get one ...
0
votes
0answers
18 views

control a robot with pymorse on MORSE simulator question

I am new to Morse and robotics. This code control the robot by giving the linear and angular velocity. This is the scene description ...
1
vote
2answers
67 views

Rotate (and stop) a large disk in very tiny increments

In a lab build I'm doing, I'm stuck at this problem, so I am fishing for suggestions. I'm creating a turn-table type setup where I need to make readings (with a nanotube-tip probe I've already ...
1
vote
1answer
29 views

Spinning disk Weapon

I am building a Hobby-weight robot and my weapon of choice is a spinning disk at the front. As regards the disk I was thinking of buying commercial (grinder-type) disks and change type of disk ...
2
votes
1answer
33 views

Diode or capacitor across terminals of brushed motor

I am currently building a hobby-weight robot (5.44kg) and will be using 2 x 14.4v cordless drill brushed motors to drive my wheels. I have read somewhere that due to "induced currents" when I turn ...
0
votes
1answer
20 views

Amperage on brushed motors

I am currently building a hobby-weight (5.44kg) robot and will be using 2 x 14.4 cordless driller motors for my wheels. The thing is I keep reading about high amperages when working with r/c models ...
2
votes
2answers
88 views

Self Powered Quadcoptor

I have this idea or a very curious question in my mind. I am no where near professional though, but i would like it to be answered. We all know how wind turbines can be used to generate electricity. ...
1
vote
0answers
40 views

Advice on mounting a servo for a nerf sentry gun

I am trying to make a nerf sentry gun to shoot my co workers. I am building it more or less from scratch and have come to the part where I need to come up with plans to assemble it. I am looking for ...
2
votes
1answer
43 views

A general question about PID Controller

I have a basic question because I'm trying to understand right now a concept that I thought it was obvious. Looking at this video he is going to feedback the variable state x with the input of the ...

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