# All Questions

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### How is it possible to maintain the total thrust when controlling yaw of a quadcopter?

I'm working on the control of a quadcopter and I'd like to understand how come controlling the yaw does not increase the overall thrust. My understanding is that the control is carried out through 2 ...
5 views

### joining an esp8266 wifi module to an access point

I am experiencing a problem with joining my esp8266 to my local network using the command AT+CWJAP="SSID","PASSWORD" However all other AT commands do respond well. The aim is to send commands from an ...
16 views

### How do I work out the kinematic solution of a robot arm?

I draw a robotic arm in Solidworks, but I'm not so sure about how to find out the DOF, forward and backward kinematic. Could anyone help me understand how to work out the kinematic solution of this ...
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### Raspberry Pi for a beginner

Im a java developer and know python little bit.I want to make applications for Rasberry Pi.Can anyone please guide me to do Rasberry Pi Applications. Is there any emulators exist for test the ...
26 views

### how can ı reduce this block diagram?

What is the reduced form of this black diagram? I can't see any solution way :(
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### EKF-SLAM Computing the jacobians for landmark updates

I've been working through this informative guide on EKF-SLAM but I'm having difficulty understanding the jacobians required for the 'landmark update', on page 35. What exactly is Jxr and Jz taking as ...
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### EKF-SLAM, how best to manage the 'P' covariance matrix, programatically

I've recently been learning about SLAM and EKF-SLAM. I've began my implementation in python, but have had trouble managing the updating of P, especially when it comes to adding new landmarks. ...
33 views

### Quadcopter Propeller size + Motor

i would like to build quad that uses bigger propellers like 15" . My question is what kind of motor shall i use ? Low or high KV? Do all motors support this kind of propellers ? Will they burn because ...
23 views

### SLAM noob here, a few questions regarding EKF-SLAM

I've recently been learning about SLAM and have been attempting to implement EKF-SLAM in python. I've been using this great article as a guide. Some progress has been made, but I'm still confused by ...
21 views

### Low power to motors — motor power jumper issue

I'm currently working on my first robotics project using the Initio kit from 4tronix powered by Raspberry Pi. The setup was fairly simple, and I've been testing it out over the last couple of days. ...
22 views

### Jacobian transpose: how to calculate orientation error

I'm confused about how to compute the error in orientation. All the documents I've read don't explain how to do it. The error in position is simply the difference between the points. Let's assume ...
50 views

### RGB-D SLAM - Compute Information Matrix

currently im working on a RGB-D SLAM with a Kinect v1 Camera. In the front-end the SLAM estimates the pose with Ransac as an initial guess for the ICP. With the pose estimation i transform the ...
27 views

### Verifying motor selection calculations

I'm trying to select a brushed DC motor for a project. I tried following the advice on sizing electric motors, mentioned in this question, but a few details were missing, and I'm unsure if I properly ...
66 views

### Calculating acceleration and velocity

I'm writing some Quad Copter software and beginning to implement an altitude hold mode. To enable me to do this I need to get an accurate reading for vertical velocity. I plan to use a Kalman filter ...
30 views

### Monocular vs. stereo computer vision robustness for object detection

Are there some genaral rules for the robustness between monocular and stereo vision when considering object detection? I am especially interested in the automotive field - considering ...
28 views

### Control a Quadcopter with an xbox 360 controller

I was considering making a quadcopter, but those controllers are to darn expensive. I was wondering if I could use an xbox 360 controller to control it since it already has the two joysticks. I was ...
29 views

### Controlling the iRobot Create 2 with MATLAB

I teach a university sophomore level MATLAB programming class for engineers, and I am planning on using the create2 for their final project. There is a nice simulator and MATLAB toolbox for the ...
32 views

### Roomba Create 2 problem reading distance traveled

I am trying to work with the create2. In using the "get distance traveled" command (id 142) I am getting back incorrect data. My simple test case logic is I am working with the ...
52 views

### What wireless technology to use to control robots in classroom?

I want to build a cheap robot programmable in Scratch graphical language, that could be employed during lessons in school. Scratch code is interpreted on a PC, so on the robot there should be only the ...
15 views

### How to calculate the real time RPM of motor with rotary encoder?

I want to measure the real time RPM of the wheels. I think incremental rotary encoder would be good. But i am confused on how to interface it with DC brushless geared motors. From the images i am not ...
21 views

### DYNAMIXEL MX-106-R burnt

I am using a MX 106-R dynamixel servo for a project that i am making. I am making a robotic arm controlled by this servo. I accidentally moved the horn of the servo while it was on and hence due to ...
93 views

### how to implement tracking problem with PID controller

I'm trying to implement the tracking problem for this example using PID controller. The dynamic equation is $$I \ddot{\theta} + d \dot{\theta} + mgL \sin(\theta) = u$$ where $\theta$ : joint ...
28 views

### the specifications graph showing the battery discharges in volt per time

my name is dylan we are doing a project on irobot create and we would like to know the specifications graph showing the battery discharges in volt per time and my robot is the irobot ceate 1. The ...
28 views

### Dock command does not seem to work

We bought a new Create2 robot and started using it. But when we issue the dock command the robot moves for a bit and does not go back to the base. The base is not hidden or obstructed and the create2 ...
22 views

### I need the specifications for irobot create 2

i need the specifications for create 2. i need it for research purposes. so i think i'm gonna need a high computational computer on board. Please suggest some nice configuration.
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### Graph optimization with G2O

I'm trying to do graph optimization with G2O, mainly in order to perform loop closure. However finding minimal working examples online is an issue (I've found this project, as well as this one. The ...
16 views

### Datalogging from Arduino Mega to Dropbox

I have an Arduino Mega board and the Adafruit Ultimate GPS Logger + GPS module shield. I have these two connected together using headers and have the entire thing mounted on my drone. Currently, I ...
52 views

### Recommendation for good source of Robotic Components

Im looking for a good source for robotic components like sheel/tracked robot chasis, motors, sensors, communication and mechanics. I thought about using raspberry and arduino as platforms for ...
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I want to build a quad copter. I want to know how do we calculate thrust or lift generated by using a motor, I am not aware about the capacities of motor. So can you explain how to calculate thrust or ...
16 views

### Sporadic sensing rates for hc-sr04 ultrasonic distance sensor

Been working on a robot recently which uses ultrasonic sensors for an integral part of the navigation. While testing the sensors I noticed a strange behaviour, the sensors seem to frequently stop ...
35 views

### How to calculate the center of mass Jacobian matrix of a robot arm

I have a 4-DOF robot arm system with 4 revolute joints arranged in an open-chain fashion like below: Assume that each link’s mass is a point mass located at p_i and each link’s center of mass is ...
56 views

### Implementation of wall and obstacle avoidance

I have a task of developing a simulation of an adaptive robot control system but I don't seem too have anyone to discuss my uncertainties with. I want to keep the simulation as simple as possible as I ...
37 views

### Controlling an ESC for Brushless Motors with an RPi

I'm looking to build a new (first) quadcopter without the conventional flight controller and radio, with an onboard RPi and applying some newfound knowledge on autonomous control to improve my coding ...
14 views

### Internal Pullup Sufficient for i2c in beaglebone Black?

I plan to use P8.13 and P8.15 of the beaglebone in a i2c bitbang mode. Do i need to use external pull up resistors in my circuit? or can i use the internal pull up which is available on the beaglebone ...
21 views

### Can't connect to BeagleBone Webserver?

I'm following this getting started tutorial, connected the board to USB and it's detected as mass storage, got the driver installed (Win 64), and at the third step I wasn't able to connect to ...
11 views

### create2 does not dock

The Create2 does not seem to see the infrad light or the base does not emit. I moved just a foot or two away from the base and then issue the dock command but it never goes back. any idea why? this is ...
11 views

### where can I get openinterface.py?

I am trying to program the create2 irobot using python. there is a script called openinterface.py. where can I download this script?
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### Robotics SLAM datasets - scaling factor

There are several robotics datasets for SLAM, like this one. In this webpage you can see that the depth image is scaled by a factor of 5000, so that float depth images can be stored in 16 bit png ...
27 views

### Difference between planetary and precision gear motors

i'm working on a building a rover and would like some advice on selecting motors. In particular, i want to understand the difference between precision and planetary gear motors. My robot will way ...
84 views

### How to tune a PIV controller?

How could I tune the above PIV controller? I am trying to get the system to have a settling time of < 1 second, P.O < 15% and zero steady state error.
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### What is the link between a quadcopter transmitter pulse and the roll/pitch/yaw angles?

I want to design a data logger for my quadcopter using the Arduino Mega board. I want to record the roll, pitch and yaw angles each second or 5 seconds, so they can be viewed later after a flight has ...
32 views

### Is motor current proportional to thrust?

So I was making sure my circuit for an airboat I was working on was safe. And checking a motor, it has 35 amps max current running 11.1v at 1000. (However my ESC has a 30 current, 40 burst amps). ...
19 views

### Using can bus on jetson tk1 [closed]

There is a core file in linux kernel, which deals connection with CAN bus using native tk1 spi. How can I use it? How can I send and receive messages from can bus using tk1? ...
31 views

### Remote Control Relative to Driver

Is it possible to remote control a 'robot' relative to the driver with an angle sensor (or any other sensor)? For example, if the robot starts in this position ...
104 views

### Basic general question about controllers

Suppose I have a mechanical system which is free to move on a given rail [-5m, 5m] like a motorized cart. The whole system can be mathematically expressed through a linear timeinvariant system ...
11 views

### Determine current roomba state / operating mode

Using the SCI messages, I would like to determine the current operating mode or state of a iRobot Roomba 780. Finally, I would like to detect and separate three states: Cleaning In docking station ...
17 views

### mobile robot behaving strangely while rotating and reversing in Gazebo simulation

I wrote a basic URDF model for a robot with two wheels at the back and one caster wheel at the front. Then, I am using "turtlesim teleop" to control the robot using the keyboard. But the robot is not ...