Questions tagged [mobile-robot]

A robot which is capable of moving from one place to another, usually of its own volition.

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Define system forward dynamics with sympy

I would like to model the dynamics of a robot via the usual discretized system of equations $$ x_{k+1} = f(x_k, u_k) \qquad x\in\mathbb{R}^{n_x}, \quad f:\mathbb{R}^{n_x}\times\mathbb{R}^{n_u} \to \...
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Displaying a png-file on a display - stays black

In Webots with a Python controller: I have a PNG-File (640x480) which displays a Matrix-Numpy-Array-figure which is getting produced by my code. I would like to display it on an Display overlay. But ...
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Create A Half Cylinder in PyBullet

I would like to ask if it is possible to use the PyBullet function createCollisionShape to create a half cylinder in PyBullet? If so, how should I do that? Or, is there any other function in PyBullet ...
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How to access the values of a batterie of a charger within the controller.py?

I have a mobile robot and I want him to learn: Green-light = Energie = I should drive towards it. In the beginning the robot drives arround randomly and when it enters a Charger it connects getting ...
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The mobile robot doesn't reach to the max speed

The youBot mobile robot is being used to test some kinematic controllers. There is a problem with the base not reaching the maximum speed. A maximum linear velocity of 1.5 is defined in the ...
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Batteries loose functionality

In Webots: I want my little robot drive to a fully charged charger (green pointlight and cylinder) and drain its energy. While the batterie loose energie it sould change its coulor. It works as long ...
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Webots: Increase Calculation Speed On Supercomputer

I am using a supercomputer (MSI, Minnesota Supercomputing Institute) to run my Webots simulations. However, on my own laptop (MacOS) the amount of time necessary to calculations is much shorter. I was ...
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Infinite world that wraps around

In webots: Is it possible for an infinite arena where your mobile robot can drive out left of the arena an come back on the right? Like a wrapping world.
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How does the lightsensor values work? Lightsensorvalue into Percentage

In Webots: I try to build a Braitenberg vehicle so that when it receives light information through the ligh sensors it drives either away or towards the light. I used an ePuck and tried to just ...
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Ideas on how to create kinematic model of skid-steered rocker bogie mobile robot

I'm trying to derive the inverse kinematics of a skid-steered mobile robot with rocker-bogie mechanism. I learned how to derive the kinematics via transformation matrices as per "Kinematic ...
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what exactly is 'observation model' for a robot

In my journey to understand the Kalman filter, I understood how a state model representation is derived for a robot and why(to get the robot state for a given input u) it is required. $$ \boldsymbol{...
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Turning a mecanum wheeled robot at a specific angle i.e 45 degree

I am implementing inverse kinematics for motion control of a robot with four mecanum wheels. However I am not getting how to turn it at specific heading angle(45 degree)? I am using encoders to check ...
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Difference between stripboard and breadboard

I'm new around here. I've observed individuals using stripboard. Could you please explain the difference between a breadboard and a stripboard? Are stripboards internally connected ? I've stripboard ...
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Question about 4-mecanum wheeled mobile robots

I'm trying to make a mobile robot with 4 mecanum wheels. The method that I've chosen is to fuse the sensors(encoder, imu) with EKF and use the SLAM algorithms(Gmapping, Cartographer, etc..). Right now ...
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How to fuse IMU with encoders in EKF

Background I have a car-like mobile robot (4 wheels, where the forward ones are steering wheels) and I want to estimate its pose and velocity assuming 2D planar motion. I'm trying to solve this ...
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Need suggestions for wire size, wire connection, etc. for building an autonomous mobile robot

I am a newbie and I want to build an autonomous mobile robot. I am using 4 brushed DC motor (stall current 5.0A). I am using four MD20A motor drivers (20A continuous, 60A peak). The wire coming out of ...
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ROS: frame transformation (tf) + TimeSynchronizer?

How to get a frame transformation using TimeSynchronizer? I am developing some 3D recognition application for a mobile robot. The robot has an RGB camera, depth camera, and uses rtabmap for SLAM, so I ...
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How to choose the correct power switch ratings for robotics?

I am making a hexapod with MG996R servos and according to the specifications, each servo has a running current of 500 - 900 mA and a stall current of 2.5 A at 6 V. Since I am making a 3DOF hexapod, ...
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Why are GA applied for mobile robot path planning

I try to understand why most researchers are using GA for mobile robot path planning. In the Paper Path Planning for the Mobile Robot: A Review it shows its the most used. In the paper A Review of ...
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Robot-to-robot relative position over time?

I have 3 robots and I know the starts and end coordinate of each of them. For example for Robot 1 I have Xr1, Yr1 and Xr2,Yr2 coordinates pair , same for Robot2 and 3. I have lateral cameras so can ...
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Is it possible to use coordinates to modify the floor into a polygon in Webots?

I'm using Webots to model an irregular polygon floor for a coverage problem. I want to define the floor using the coordinates of the vertices. So far I have been able to generate an irregular polygon ...
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Why in forward bending knee orientation in quadruped legged robot require less torque in knee joint?

I'm trying to find answer in terms of physics explanation, why knee joint torque requirement is less in the forward bending leg orientation of a quadruped legged robot. I'm referring this article, in ...
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Suggestion for path following algorithm for mecanum wheeled mobile robot

I have a robot with four Mecanum wheels. I want to make robot follow different paths. The path information is given in x,y coordinates. I want to start from simplest controller i.e. open loop type as ...
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BLDC Motor characterization for a towing AGV

I’m working on an aircraft towing AGV and I need some assistance regarding the drive sizing. But first some technical data : 4 DC bldc motors Cogged wheel for caterpillar tracks diameter 65mm. ...
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How to move the robot using raspberry pi?

I used a raspberry pi 3 model B and a camera to make a robot detect fire, using https://www.youtube.com/watch?v=-ZyFYniGUsw However I am not sure how to make this robot move after it detects fire. The ...
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control over changing data

I am trying out different control algorithms, in my practice on the state space models and control. Now I have the following system with the following states and state transitions with time. Position ...
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what are the main steps to build a swarm robots system and train it to achieve foraging task using deep Q network

I studied reinforcement learning deeper and prepared myself to use Webots, and when I decided to build a swarm robots system and drive it by deep_Q_networks I feel too confused how can I begin and is ...
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Why does the complexity of the particle filter scales exponentially with the number of dimentions?

In the AI for Robotics course from Udacity, Sebastian Thrun mentions that "the complexity of the particle filter grows exponentially with the number of dimensions". Why is this the case? We ...
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URDF for a real robot

I have been making robots in ROS/Gazebo simulation before, which makes use of the URDF to understand the robot model, different frames and transformations. For a real robot, do I need a URDF as well? ...
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Differential Drive Control Techniques

I have a mobile robot that has a differential drive technique. I try to control the robot with PID controller. Is the best way for controlling differential drive robots? If I want to compare different ...
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Move a Three Wheel Omni Robot

I understand this isn't for programming but it's easy to read. I have referenced This for a guide on how to move a 3 wheel omni robot but I have encountered a few problems. ...
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Choose the structure of the dynamic model for the generalized equations of motion of the robot

I ask the robotics specialists for help as I am a little confused. I have two subsystems which are shown in the picture below: One of them is a system of stable and controlled differential equations ...
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torque calculation issues

so i have been trying to draw a free body diagram of a 6 axis robot arm project, in order to know the torque required for each joint. and now am confused about the angular acceleration part which ...
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Mobile robotic arm camera position

I'm working on my graduation project which is a mobile robotic arm that performs pick and place tasks. I wanted to know the possible ways to mount the camera where i can reach the desired destination ...
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4-Wheeled Mobile Robot, Motor-Torque, RPM Calculation

I want the torque, rpm of every motor to be used considering certain factors, in a 4 wheeled robot as you see in the picture below. Here are the factors affecting motor specifications that I Had ...
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What is the most cost effective yet still reliable outdoor boundary system?

I am working on a robot that will operate outside in people's lawns in a predefined space. The issue that I am having right now is figuring out what kind of boundary system I should implement in order ...
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Dynamically-stable Motion Planning for Humanoid Robots

I was reading the classical robotics paper Dynamically-stable Motion Planning for Humanoid Robots and I don't understand why the two trees are swapped in line 7 of figure 5 (page 11). Seems like an ...
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Drive unicycle kinematics equations through the geometry

The unicycle dynamics in discrete-time is given by: $$ \begin{array}{l} {x_{k + 1}} = {x_k} + \Delta {s_{k + 1}} \times \cos ({\theta _{k + 1}})\\ {x_{k + 1}} = {x_k} + \Delta {s_{k + 1}} \times \sin (...
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Does full motor current pass through 'switches' on children's driving vehicles?

I plan to hijack a powerwheels-like toy to control it with the jetson nano. Here is the toy: https://www.wayfair.com/outdoor/pdp/konbeca-ride-on-bumper-car-kids-toy-electric-funny-ride-on-car-for-360-...
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Do diagonal mecanum wheels require the rollers to cross the center of the robot

I'm currently in the process of making some changes to my robot to use mecanum wheels. The kinematic models I've seen assume the 45 degree roller from one diagonal wheel to the other, crosses the ...
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Some doubts regarding SLAM and its technical terms

I have some questions regarding SLAM and some general technical terms used in the context of it. Q1) **Online SLAM vs Offline SLAM**. Can "Online" SLAM be also called "real-time" SLAM? What is the ...
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Count number of collisions while navigating to goal

I have the navigation stack working in ROS Kinetic on my computer. In Stage ROS simulations, I can specify the goal and the robot navigates to it. I need to count the number of collisions (if any) ...
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Calculate information matrix for graph slam

0 I am new to SLAM. I am working on graph slam where I need to do pose graph optimisation. For this requirement information matrix is required between two edges for which the transformation has ...
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Reinforcement Learning in global and local path planning for mobile robots and self-driving car

Most RL courses start with grid world problem like this where robot has to navigate from start to end and RL helps in generating the optimum policy. (State-action pairing). I am not able to relate ...
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Can a state lattice planner be used purely as a local planner?

I've been reading a bit about state lattice motion planning recently. The question I would like to ask is if a lattice-based motion planning system can be used purely as a local planner without a ...
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How to design a PID controller for boat?

I have a boat with two trusters and a trajectory planner which is based on the bicycle model. In order to control the boat, the linear velocity of each truster has to be provided. The following ...
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Calculating wheel linear velocity from body velocity

A frame {b} is attached to the centre of a robot chassis. The planar configuration is given by $(x,y,\phi)$ where $\phi$ is the angle between the x axis in {b} and the x axis of a fixed reference ...
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Small AGV robot for ROS application

I am looking for an off-the-shelf small AGV which runs or could be used with ROS. It may include some basic sensors like a camera, an IMU, an Ultrasonic range finder, etc. Really appreciate all the ...
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Autonomous harvesting robots. What are model possible components and interactions for the entire system? [closed]

I found a video which talk about best autonomous robots that use IA technology to harvest crops. The video is very interesting because, the “ecosystem” of each robot varies a lot from company to ...
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How to actually fuse sensor using Extended Kalman Filter

Background I'm working on 4-omniwheel mobile robot. It have encoder on each wheel and MPU 6050 IMU. The robot positioning suffer a great error because slip, so i try to increase the accuracy of ...

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