# All Questions

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### 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 ...
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### 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: ...
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### 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 ...
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### 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 ...
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### 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 ...
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### 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 ...
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### PID Control Tuning

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 ...
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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 ...
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### 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 ...
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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 ...
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### Tilt-Compensated Compass Problem MPU9150

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 ...
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### 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, ...
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### 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 ...
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### ros node does not seem to do anything

I have the following code for the ros turtlesim: ...
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### 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 ...
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### 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 ...
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### 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 that guide on setting it up on the internet, so was wondering if it even is ...
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### 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: - ...
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### 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 ...
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### 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 ...
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### 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 ...
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### 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 ...
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### 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 ...
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### 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 ...
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### 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 ...
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### 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 ...
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### 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 ...
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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. ...
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### 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 ...
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### 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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### Brushless DC motor -driver circuit

How to run my Brushless DC (BLDC) motors? Apart from using ESCs, how can I control my motors? I need a perfect motor driver and so can anyone send me the circuit diagram?
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### Robot docking for self-recharging

I want to build a simple obstacle avoider robot, but this time I want it to be self-recharging so I am building a dock for this purpose, so I want it to be able to locate the dock and go for it when ...
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### Interface multiple I2C slaves to microcontroller

I want to communicate the Tiva C ARM Cortex M4 to sensorhub from TI which has multiple sensors with different I2C addresses such as MPU9150, BMP180, Temperature Sensors... With a single I2C slave, i ...
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### Making wireless video transceiver with Raspberry pi

I'm trying to make video transmitter using raspberry pi. I'm trying to send data using 433MHz communication, (CC1101 transceiver) And this can be connected to raspberry pi using SPI connection. I ...
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### Microcontroller programmer

Can anybody tell me how to start with microcontroller programming by designing my own on chip flash progrmmaer, starts with an 8 bit controller.
58 views

### is it possible to track movement on a tennis court?

I'd like to track my run in an indoor tennis court. GPS won't be available so I was thinking researching for other solutions: Accelerometer: I concluded it's a no go because while playing tennis the ...
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### Short distance ball transport

I'm looking for a way to transport balls (diameter 50mm) 220 mm up with over a slope with a length of 120 mm. Currently I'm considering the usage of a belt system but I cannot seem to find a good belt ...
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### Acceleration formula for a differential steering robot

I have the formulas to derive the RPM's of each wheel from the robot's linear velocity. Now, I am trying to do the same thing for the acceleration (mainly angular acceleration). For linear ...
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### tricopter simulation to test control algorithms

I am looking to write and test my own control algorithms for tricopter flight. I am looking for a simulator that can simulate a tricopter but at the level of receiving simulated PWM and returning ...
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I'm building an autonomous sail boat (ripped out the guts of an RC sail boat and replaced with my own mainboard etc.) The controller board I have can accommodate both an MPU9150 and an HMC5883. Is ...
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### MPU9150 - Yaw angle Drift

I use MPU9150, also use DCM and Complimentary filter to compute roll, pitch and yaw. However, my Yaw is not so smooth. How can I solve that problem? I looked at the datasheet of MPU9150, but I didn't ...
I have a question regarding the implementation of a quadrotor's position controller. In my Matlab model the quadrotor takes 4 inputs: a desired altitude ($Z_{des}$) and desired attitude ...