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17 views

Trajectory tracking problem for non-holonomic mobile robots

Currently, I am working on the trajectory tracking problems of autonomous ground vehicle and a little confused about the applicability of control theory for different types of wheeled mobile robots. ...
0
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0answers
27 views

Quadcopter motors not spinning

I made a quadcopter with an Arduino and all connections are fine. When I arm it, the motors spin without props but when I connect the props and arm it, the motors spin for a second and stop. Can ...
1
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1answer
45 views

How to render a robotic arm in Unity?

As part of a research project, I'm creating synthetic data, using the Unity engine. I have the final pose of a robotic arm (6 params: 3 for orientation, 3 for location/position), and also a .ply file ...
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1answer
21 views

How to determine x-axis if the two z-axis are parallel in Denavit Hartenberg representation

I have problem of determining the DH table, specially finding x axis when two z axis are parallel to each other
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1answer
44 views

EKF SLAM : SLAM specific Jacobians for new landmarks

I am currently trying to understand the books SLAM for dummies and Simulataneous localization and mapping with the extended Kalman filter to implement slam. I have understood steps 1 and 2 SLAM for ...
0
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0answers
18 views

BTserial.read() parameters

I am new to programming Bluetooth modules with Arduino UNO and would like to read a light sensor remotely and turn lights on remotely. Can I put an address of a HC-06 or HC-05 into the BTserial.read() ...
-1
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1answer
35 views

Can drone fly in predefined fixed trajectory without GPS

Is it possible to make a drone to fly in fixed altitude and move in fixed trajectory without GPS. (Drone has to move in fixed path which is already defined). I am saying without GPS because drone has ...
0
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1answer
21 views

Best way to turn large “lazy suzan” bearing with stepper motor [closed]

I'm designing an automated object capture turntable (take photos -> photogrammetry) where the platform the object sits need to rotate, driven by a stepper. The catch is the base is glass as I need to ...
0
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1answer
48 views

How does 3D Lidar work

It is a beginner question for most of you, I had Google this question but I didn't reach any satisfied answer . What is the returned raw data from lidar,difference between 2d and 3d lidar ? How we map ...
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0answers
30 views

g2o Graph optimisation, What edge to use for a distance constraint?

//cross posted from stackoverflow. If that is not ok, I will delete! I have an optimisation problem that I am trying to solve with g2o I have a data set which is N noisy Poses (XYZ), and known (less ...
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1answer
31 views

Can neural network probability directly be used as inverse sensor model?

For my robot i'm using semantic segmentation neural network that assigns to every pixel probability of being "road" (not occupied). By using homography matrix i'm re-projecting image to top-down view. ...
0
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0answers
30 views

ROS meta-package ros-melodic-desktop-full doesn't include mav packages

Why doesn't the installation of the meta-package ros-melodic-desktop-full on Ubuntu 18.04 Melodic include the packages ...
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0answers
37 views

PID to control discharging current of battery

i want to maintain battery cell voltage at specific setpoint for that i am varying discharging current by monitoring cell voltage. for that i m using https://github.com/br3ttb/Arduino-PID-Library for ...
1
vote
1answer
78 views

UR5 Visual servoing(image based, eye in hand)

I am implementing IBVS on a UR5 using ROS. The algorithm works very well in linear X, Y and Z and omega Y. When I try to add a fifth axis(omega X or Omega Z), the robot jerks heavily and goes into ...
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0answers
37 views

How do I set the weights of an Unscented Kalman Filter?

In most of the papers I have read, calculation of weights is done by the following formula: Where L is the dimensionality of my state and lambda is calculated by: And the usual values for alpha, ...
2
votes
1answer
37 views

Helium Balloon Altitude and Velocity Control System

I am designing a helium balloon which implements a control system that can expand and contract the balloon using a motor, thereby increasing or decreasing buoyancy and, subsequently, acceleration. I ...
0
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0answers
23 views

Servo malfunction

Summary I am making an automatic door for my chickens including a servo motor. In the process I actually shorted my 5V from my Arduino. The servo is powered by external batteries and only gets its ...
2
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0answers
28 views

Robot Hand to Eye calibration without joint encoder

I have two degrees of freedom robot with a camera mounted on the tool center point where the system is modeled as $^wT_c = {^wT_z}(\theta_1){^zT_m}(\theta_2) {^mT_c}(\textbf{r})$, $\textbf{r} \in ...
1
vote
2answers
59 views

Which controller (PI or PD) is generally more robust to noisy sensor measurements and why?

Assuming no filter is used to measure error (or rate of change in error) with respect to a desired state, would a PI controller more/less/about equally robust to signal input noise compared to a PD ...
1
vote
1answer
33 views

EKF SLAM : Missing older landmarks in new observation

I am a beginner to SLAM and robotics in general and I have been trying to implement SLAM on my GoPiGo3 robot car kit using primarily Chapter 10 from Probabilistic Robotics by Sebastian Thrun as ...
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0answers
19 views

How can I pass I/O through to the host system in Fanuc's ROBOGUIDE

In Fanuc's ROBOGUIDE software, one can "simulate" digital I/O when in the program through the use of the virtual Teach Pendant. This, however, is much too slow for me to do in real time, as the ...
0
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0answers
13 views

Gazebo Compatibility with Red Hat Enterprise Linux Distribution

Does anyone know if it is possible to install and run Gazebo on a machine using the Red Hat Enterprise Linux Distribution? The company I am working at doesn't allow users to run Ubuntu typically so ...
0
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1answer
59 views

Resolved Motion Rate Control, Rotational Part

I'm controlling 6 DOF robot arm based on image processing. Robot arm will grab the object. Below what my system looks I can control the translational part of robot very well. But i cant control the ...
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2answers
55 views

Why are brushless servos more common than steppers in Cobots?

Essentially every cobot I've worked with uses BLDCs instead of stepper motors in the joints. When searching for answers as to why I see a lot of posts that suggest one or the other, but nothing ...
1
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1answer
28 views

Action client waiting forever for server to start

I'm in the process of writing an action cpp file and the client side seems to be stuck waiting for the server to start and I'm not quite sure why. Here's the code: ...
0
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1answer
45 views

PID control loop and feedback acquisition synchronization

In many real-time PID control loop application I have seen that the control loop is triggered exactly as the ADC interrupts arrives in order to achieve maximum synchronization between feedback ...
1
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0answers
46 views

How to publish odometry from 3 wheeled omnidirectional robot?

I'm new to ROS and robotics and I'm trying to implement the ROS navigation stack in a 3 wheeled omnidirectional robot. I already made the map using RTABMap but now I'm stuck in the 'Publishing ...
0
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1answer
72 views

Matlab Code for Lynx Robot

In this section, you will need to write a function lynx_fk which returns the positions of 10 points along the robot arm as defined later, given the joint angles of the robot. For this question, ...
2
votes
1answer
23 views

When are non-diagonal matrices advantageous for linear quadratic regulators?

When setting up an optimal control problem using a linear quadratic regulator, one often chooses semi-definite matrices Q and R such that the objective function J has the form $$J=\int_{t_0}^{t_f}(...
2
votes
0answers
45 views

Particle filter with error states

I am new to particle filters and I have a particle filter based on this: $$x_{k+1} = f_{k}(x_{k},\omega_{k})$$ $$y_{k+1} = h_{k}(x_{k},v_{k})$$ $$x = [\delta \phi, \delta \theta, \delta \psi, \delta ...
0
votes
1answer
53 views

Rotation Matrices Using DH Parameters

I need to find rotation matrices between the frames of references of the vertices of the cube, and the DH parameters. For the rotation between the first to second frame of reference, I got alpha as pi/...
1
vote
1answer
45 views

calibrating large scale manipulator

I'm facing the problem of model calibration for a large-scale manipulator (e.g. example image) with a half-spherical workspace of around 40m diameter. The typical approach would be computer vision, ...
4
votes
1answer
80 views

Not able to communicate with Roomba with serial port

I have an IRobot Roomba model number 565 and I am trying to control it with a Wemos D1 mini with Roomba's OI. I connected the TX and RX pins from my FTDI adapter to the Roombas RX and TX and I can ...
1
vote
1answer
56 views

Tuning PID controlling car's steering angle

We built a car model with Ackerman steering type for line following task. The distance between rear and front wheels' axes was about 42 cm. Then we tuned PID controller (really just PD: Kp = 0.9, Ki = ...
0
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0answers
74 views

Information Gain Theory - Conditional Entropy

In the book "Probabilistic Robotics" in chapter 17.2.1 they describe the theoretical concept of information gain regarding to robotic exploration. I'll provide you with an excerpt: In context of ...
1
vote
1answer
43 views

Number of inverse kinematics closed form solutions for ABB IRB 140

I've read that 6 dof manipulators give eight closed form solutions, according to a paper. What is the number of iK solutions for the ABB IRB 140? (last three axes intersect but there is a offset ...
2
votes
1answer
56 views

Home position of robot created using modified DH Parameters doesn't match the real robot

I have created a 6-DOF robot using RigidBodyTree() method and modified D-H parameters using robotics toolbox in MATLAB. The modified DH parameters for the robot are as follows: I have followed the ...
0
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1answer
34 views

how to implement autonomous navigation using lidar and hector?

I want to make an autonomous mobile robot, which can localise itself and navigate to the goal in an unknown environment. As sensor, i just have a RPLidar to get laser scan, that's it. I used Hector ...
0
votes
1answer
55 views

A Delivery Drone

I'm building a delivery drone as my final year project. A drone that can deliver a package to offices around my small town autonomously, for my final year project. I would like to know how this drone ...
1
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1answer
52 views

Robot mechanism parts names

I'm working on my first "robotic" project that involves a square platform that should drop one of the four sides at a time. ...
1
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0answers
33 views

Parallel Inverse Kinematics for Multithreaded Architecture (or GPU)

Here, you can find a nice academic paper about this topic. What I am looking for it is a real implementation of it or, instead, any other implementation of IK algorithm that can run in a many-core or ...
0
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0answers
24 views

Planning minimum snap trajectories

I am working on motion planning algorithm for quadrotor. As I have learned in Coursera Aerial robotics course, trajectories for quadrotors should minimize snap which is equivalent to interpolating ...
1
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4answers
109 views

Is Fuzzy logic applicable for robotics research

I found some papers that use fuzzy logic to solve robotics algorithmic problems. But I have recently been told by a few roboticists that fuzzy logic should not be used in robotics because it has ...
2
votes
1answer
48 views

Task oriented robot language?

So, what I understood by the term "Task Planning" is, "to implement a task to be done by a robot by mimicking a real-world scenario". This article is also using the term "Task" but it is saying ...
0
votes
1answer
38 views

Are these parts compatible to build a quadrone?

I want to build a quaddrone from scratch, without using ready made controllers. I've read a lot about drones, how they fly and what essential parts they should have. So I decided to make my own ...
0
votes
2answers
30 views

What is the typical intro example for control systems for a spherical joint?

I have been studying Acrobot and Cart-Pole. Both of these systems I can both work out the equations of motion and linear manipulator equations for how to maintain the poles vertically. The problem ...
3
votes
1answer
45 views

What does it actually mean by Task Planning?

According to the research paper Parallel process decomposition of a dynamic manipulation task: robotic sewing (D. Gershon, DOI: 10.1109/70.56654): Abstract - ... The task planner approach, as ...
0
votes
1answer
37 views

Buying DC motors with fitting gears

I want to try a little project with an arduino controlled crossbow turret. Therefore I need some motors to move the turret and gears. Since this is my first try on such a project I am very unsure on ...
1
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0answers
38 views

how to solve action client not connected?

does anyone knows how to solve error "action client not connected" this is error text: ...
0
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0answers
23 views

Roomba 651 makes sound

Our roomba 651 makes always the error sound. But battery is ver good. We are not able to find the solution. If any one has the solution to it.

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