# All Questions

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### Looking for Beginners Tutorials on Navigation Stack and SLAM with Gazebo

As an undergrad working with SLAM algorithms, I'm looking for a step-by-step introduction to ROS navigation stack and gazebo. I am thinking of creating a simple box with a horizontal LiDAR array ...
38 views

### Any way to program a robot remotely?

So Udacity, Kuka and KIT are/were offering a Kuka challenge. Basically, the participants got to write code and run it remotely on a Kuka robot based in the KIT labs in Germany and submit their code ...
45 views

### How to handle multi-sensors data [closed]

I am new to sensor data fusion world. I want to find room vacancy using ultrasonic, PIR and sound sensors. These sensors deliver binary information about the occupancy. How can I combine the ...
37 views

### Robot arm with steppers - speed

I am using a 5 axis Robot arm (Robolink robot from Igus) to perform some 3D printing routines. By now I am trying to use them and have him have some good position (and speed) control. The robot is ...
30 views

While going through this Page on different types of navigations used in AGV's for Industrial Environments. I came across natural navigation which claims to reduce installation time and cost for the ...
17 views

### What parts of the flight system could you remove if you only care about flying up/down?

If you only need a drone to fly up/down, how could you simplify the flight system? What parts/propellers could you remove for instance? Could you enable a drone to fly vertically with only one ...
37 views

### Debuging ROS on a Jetson Xavier

I have configured ROS melodic based on the RACECARJ and MIT-Racecar Github repos. Everything runs perfectly on my desktop Linux 18.04 machine. The script should be able to install the same also on ...
15 views

### RpLIDAR unable to see black objects

I am working on a ROSBOT for a natural navigation project. While working with RpLIDAR A2 version, I found that it does not sense thin black surfaces like black pants/trousers while at close range (...
32 views

### Lifting robot that moves like a plotter

I'm looking for what a robot that moves like a plotter but can grab a load up to 1kg with a claw, lift, rotate and place in another location within its range. What is this type of robot called?
15 views

### Doubt linearizing 2D planar quadrotor equation of motion

Equation of motion for 2D planar quadrotor are as follows $\ddot{x} = \frac{1}{m} (u1+u2)sin(\theta)$ $\ddot{y} = \frac{1}{m} (u1+u2)cos(\theta) - mg$ $\ddot{\theta} = \frac{r}{I} (u1+u2)$ How to ...
37 views

### How can I specify parameter '~moveit_controller_manager'?

I followed this tutorial: Basic ROS MoveIt! and Gazebo Integration but when I launch moveit launch file from tutorial, I have error which says that I did not specify parameter '~...
20 views

### Pausing at positing in GRBL while holding motor current

I'm trying to get grbl to move the carriage of my 2D scanner to a specific position, pause there for a certain amount of time (until the sensor does its thing), and then proceed to the next position ...
92 views

### Can ROS workspace safely exist in an external HDD?

Is it safe to create and operate a ROS workspace from an external hard drive? Are there any limitations or issues I should be aware of? Tutorials and manuals typically suggest that the workspace ...
34 views

### RRT algorithm implementation in OpenGL

I was going through the RRT algorithm as I have an interest in it. I need a source code for its 3D implementation using OpenGL and C/C++. Can anyone please help me out?
32 views

### Stepper drive resolution

I'm asking for help on understanding stepper motor + gearbox solution, as I've got totally confused during my research on topic. Story: Trying to make a sort of precise turning table (at least 1°/...
44 views

### Robot moving sideways in RVIZ ROS

Hi, I have a wheeled-legged robot as you can see in the picture. When I simulate it in ROS-Gazebo it works fine, however at the same time in Rviz it moves sideways instead of forward or backwards. I ...
11 views

### How to use two topics without using TimeSynchronizer

I need an Image topic and a PointCloud2 topic to find pose but it takes so long to get the ...
13 views

### How to draw an encoder plate?

What is a good program to create an encoder plate? Essentially, what I want is: A circle of 4.8cm diameter that has 36 segments, half of which are colored in black and the other half should be white! ...
41 views

I am currently designing a 2D simulation of a 3DOFs robotic arm in order to develop a better understanding of inverse kinematic (so as to avoid breaking more components than necessary) but despite my ...
55 views

### control DC motor by Atmega and L298 code in Atmel Studio

I'm new to Atmel Studio. I used BASCOM-AVR until now. I know my question is very basic but I couldn't solve my problem by searching internet. I wrote a code in BASCOM (Basic laguage) to control two DC ...
19 views

### EKF SLAM without iterative update on observations

In Dr. Stachniss's lecture on EKF SLAM, he describes a non-iterative update method for EKF SLAM. How is this done? Can anyone explicate or provide a source on this?
124 views

### Python PID tuning - Parrot Bebop 2 - Target follower - ROS

I'm developing a PID controller for making the drone follow a detected object. I used as reference these topics: Ttracking-objects-from-camera-pid-controlling-parrot-ar-drone Tracking-objects-...
43 views

### Screw based Jacobian transformation

The mechanism shown on the picture has prismatic, revolute and spherical joints in order and I derived the screw based Jacobian in local frame $B_i$, for the isolated leg. The isolated leg coordinate ...
19 views

### Interfacing HMC5883l Compass with Arduino

I'm using an HMC5883l compass module to find the angle at which my module is pointed from magnetic North. I found this code as an example with "HMC5883L_Simple.h" library. And the results I'm getting ...
48 views

### PID control while desiring steady state offset

I have a rather niche application of PID control, and I am looking for ideas on how to solve it. Design Temperature sensor is externally mounted on a liquid vessel's body --> ...
12 views

### Improve altitude control on an outer loop PD controller for a UAV

I'm playing around with using PID control as an outer loop control for the position of a DJI drone in a Hardware in the loop simulator. I have three separate controller instances for each axis x, y, ...
35 views

### Stepper Motor power supplies

Being new to the world of stepper motors, I have a Longs Stepper Motor 23HS9430 bought from eBay it's a 3.0 A 5 V motor. Although I have been reading about the supply voltage for the motor, ...
37 views

### Target Recognition for Microcontrollers

I'm building a device using microcontrollers, and part of the device necessitates target recognition. That is to say, if there are three targets, A B and C, I want my device to know when I'm pointing ...
49 views

### ICP for LiDAR point cloud data in two frames

I am currently using the ICP to register Lidar point clouds in two frames. The problem is that the translation value calculated by the difference of average point values of utilized points in two ...
17 views

### How do I get the orientation invariant position of a 9-axis Inertial sensor?

What is the best possible way to track the orientation invariant path of an inertial unit. For example, I have an inertial unit in my palm and if I want to use it as a pen to write something (say an ...
32 views

### lucky cat - coil question

i’m building a lucky cat, these eastern cats with one of their legs waving at you all the time the system to do this is as follows: to the waving leg inside the cat is a small strong magnet attached ...
67 views

### What are the differences between trajectory planning, trajectory tracking, path planning, path following and motion planning?

What are the differences between trajectory planning, trajectory tracking, path planning, path following and motion planning? And what are the basic methods they use?
46 views

### Iterative calculation of trajectory

In the answer https://robotics.stackexchange.com/a/7512/22953 there is an example for trapetzoid trajectory planning that results in the following table. \begin{array} {|r|r|} \hline time &...
17 views

### Statistical distance between degenerate distribution and any probability distribution

In sample-based motion planning, sampling methods would change the cost of path and computation time for the same planning algorithm. I would like to compare different sampling methods. So, the ...
13 views

### How to perform system identification of a mobile robot using white box approach?

Why isn't there much research going into the extraction of inertial and frictional values? Is there any standardized approach? Edit: I will give a sample application! Say if we want to implement a ...
11 views

### Create 2 650 - clean button flashing when connected to Arduino

I am working with two different Create 2 bases (595 and 650). I am using one Arduino Mega 2560 as an interface and have been testing the same code with the same board on both bases. The issue is ...
22 views

### catkin build with multi-core make for building individual packages

I have multiple libraries and the main program. When I run catkin build command it starts with 8 jobs but after finishing building libraries continues to build the ...
36 views

### Free Multibody Dynamics Software?

I'm working on modelling a feller buncher, its end effector consists of a saw to cut trees and claws to bundle them together. I'm looking for a free/open source software that can simulate dynamics of ...
29 views

### Force controller with feedback issues

I'm implementing a force controller on a robotic arm, where the force input comes from torque sensors in the joints. I have calculated the cartesian force on the end-effector from the joint torques, ...
18 views

### Mission Planner: How to create a custom Waypoint Command

I am trying to set up a waypoint in Mission Planner that causes the drone to hover, take sensor data from a custom sensor, then either land or continue hovering based off of what the sensor data says. ...
54 views

### 3D mapping with octomap

I want to use octomap and while I tried this out I had some problems. When I started octomap_server and rviz I realized that the sensor is looking only in one way, even if I rotate my robot (my fixed ...
23 views

### Stuck pneumatic cylinder

I've just received a baomain pneumatic cylinder from amazon (50 mm bore 100 mm stroke). When I tried to move it back and forth by hand, it wouldn't budge. Ive never used pneumatic cylinders for ...
46 views

### Feedback linearization of a nonlinear MIMO system

I have to design a feedback linearization for the model of a car with a single trailer. This picture shows the system: And this is the kinematic model I got, where ...
68 views

### How to read data from the VN100 IMU on Ubuntu?

Hi I have a VectorNav VN100S Development kit, which has VN100 IMU unit. I want to set it up with Ubuntu 16.04 and ROS Kinetic, but unable to read anything from the VN-100. So far I have been ...
72 views

### Given an initial position, a goal position and a duration find a trajectory

I have an initial position $X^R_{init}$ of the robot ($x$, $y$ and yaw) and a goal position $X^R_{goal}$ I need to create a trajectory of duration $T$ with $n$ waypoints to move the robot from its ...
41 views

### Kalman Filter: Do we need to measure each entry of the output-sequence, or can we derive them?

A Kalman-Filter gets applied to a state-space model in order to obtain estimates of the state-vector. Example: Assume a car moving on a straight line in x-direction (this is a 1-dimensional problem)....
13 views

### Standard Kalman Filter applied to non-Gaussian noise data

A Kalman-Filter could be applied to sensor-readings in order to smooth them. The Kalman-Filter, however, assumes Gaussian distributed sensor-noise with zero-mean. Now, I found that my sensor-noise ...
18 views

### Question about EKF SLAM (w/ unknown correspondence) update step

In Probabilistic Robotics, page 322, the EKF SLAM update step is shown below. My question is, why is for every observed feature, $\bar{\mu}_t,\bar{\Sigma}_t$ are overwritten in lines 23,24 by the ...