# 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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### 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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### 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. ...
660 views

### ROS packages for *pre-planned* path navigation rather than path generation? (Turtlebot3/ROS)

I am working on a project in which users will create paths fully constrained in terms of position (using a separate piece of software), and a robot will periodically follow those paths. We are using a ...
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### GraphSLAM data accumulation problem

I try to implement GraphSLAM from this tutorial, The GraphSLAM Algorithm with Applications to Large-Scale Mapping of Urban Structures. I have some doubt while studying this paper. I hope people who ...
421 views

### Robotic arm servo motor- Not enough torque

I require your help regarding a problem I’m encountering. I am a beginner in robot modelling. I am designing a robotic arm for agricultural use and I am having issues with the motors. I am using ...
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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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### 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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### 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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### How to handle curved paths in maze

-I have an RPi on Ubuntu with ROS (Kinetic). The task is to solve a maze. I have implemented a left-hand algorithm to navigate through the maze. -The robot is equipped with 3 ultrasonic HC-SR04 ...
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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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### How to implement a 4 Mecanum wheel Robot kinematic model Practically in code?

Above is the Kinematic model of a 4 wheeled from https://cdn.intechopen.com/pdfs/465/InTechOmnidirectional_mobile_robot_design_and_implementation.pdf, My question is how to use these kinematic ...
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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 I need a camera along with LIDAR for SLAM?

Equipment: Pi 3 B Mega 2x Encoder Motor 12VDC 299RPM MPU 6050 12V bat 2000mAh LIDAR or Kinect ? I want to implement EKF SLAM. I have referred bot NOX ROS wandering robot, Hussarian CORE and Robotics ...
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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 ...
116 views

### Easy cm accurate GNSS / GPS for rover with base station? [closed]

I am trying to design a system to measure snow depth during snow production on a tiny ski resort in Denmark. My idea is simple: Drive a rover over the ground during the summer, and obtain height ...
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### SEIF ,online version of Graph slam create doubt in Motion Update state

I have a thesis work about Graph Slam The GraphSLAM Algorithm with Applications to Large-Scale Mapping of Urban Structures I try to implement it with the help of this paper but during the ...
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### Sprockets for steering

I'm planning to drive the steering of a AWD rover using stepper motors. Is it usually a good idea to use sprockets and chains for that? Would the precision typically be too low for steering? The ...
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### Quasi Direct Drive Actuator - Slot & Pole Combinations for High Torque Motor

I am building my own Quasi Direct Drive actuator and looking for information/ design guidelines for building a High Torque Motor similar to the MIT Mini Cheetah below. Specifically I cannot seem to ...
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### In SLAM loop closure, What does a sim3 matrix do?

I am confused between 3D rigid affine(with scale, without shear) transformation and Lie group's sim(3) matrix. 3D affine would be [sR|t; 0 1]. we rotate, scale and then translate a 3D point using ...
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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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### Can I apply a common voltage to a high speed running DC motor to stop it? Will it damage the DC motor?

I decelerate the velocity of my robot very quickly by applying a common voltage (eg. 24V to both the terminals using Motor driver) to the DC motors. Given, the motor is running at a very high speed ...
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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 ...
149 views

### Jacobian of a planar manipulator with 4 links

I have a mobile manipulator that moves on the plane. The base moves in SE(2) and the manipulator is also planar with 4 links. The mobile base will be a differential drive robot and its motion is ...
159 views

### How rational is it to use Intel Realsense for my affordable indoor autonomous robot?

Right now, I am using ESP32 for the motors and planning to add either Raspberry Pi Zero or ARM Cortex-M4 (STM32) and use ROS with Intel RealSense RGBD camera. How sensible is it? I am not expert in ...
1k views

### teleop_twist_joy with Logitech F710 Joystick force feedback error

I am using a Logitech F710 joystick game controller in ROS Kinetic Kame. I was able to perform jstest testing, and can see my joystick works well. But when I try ...
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### How to choose a motor for water surface vehicle? [closed]

I am about to build a water surface vehicle (a kind of boat). I was looking for different type motors and ruled out the stepper and servo motors. But I got confused between brushed and brushless dc ...
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### Why the bldc motor not able to move my water boat?

I have a 1100kv brushless motor from dys with a propeller as shown. I have attached this motor to two pvc pipes joined together as shown and packed the electronics inside polyform to protect from ...
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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 ...
270 views

### Plot a map using wheel encoder and IMU data

I want to plot a map( with matplotlib or any other library ) using a wheel encoder and IMU data. Eg:- For every 10cm robot moves it should draw line (in a graph) and draw angles depending on the data ...
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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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### Jetson TX2 vs small form factor PC for autonomous robots

What are the advantages and disadvantages for each? I can build a small form factor PC with a GTX 1050 which will easily out perform a jetson for the same price. When and where are each more ...
2k views

### How to implement a wall following controller for a TurtleBot3? (ROS - Python)

I want to implement a wall following controller for my TurtleBot3 (with ROS system). Sensors which I have on the robot: lidar(360) and optional 2 ultrasonic sensors on the side (one on the left and ...
2k views

### What's the diffrence between $H_2$ and $H_\infty$ control?

There a two controllers named $H_2$ and $H_\infty$. Can someone explain if: They have have guaranteed stability margins? Do they have a Kalman filter? Are they for both SISO and MIMO systems? Can I ...
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### Extrinsic calibration of a multicamera-rig mounted rigidly on a mobile robot

We have a set of 8 cameras mounted rigidly on a mobile robot. The cameras are forming an arc, which allows a 360º vision. I want the extrinsic parameters of them referred to the robot. Is there any ...
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### Localize a Mobile Robot on a Mirror

I am currently busy with a project which requires me to construct a robot capable of cleaning a heliostat (movable mirror used to redirect sunlight). Heliostats are basically large flat mirrors that ...
121 views

### How to find angular velocity using pure pursuit algorithm?

I have implemented the pure pursuit algorithm for my differential wheeled robot as described in the following paper: http://www.enseignement.polytechnique.fr/profs/informatique/Eric.Goubault/MRIS/...
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### How to calculate the ground truth of your own simple dataset for testing your SLAM Algorithm?

I have tested my SLAM algorithm on EuRoC, TUM and KITTI Datasets. But I would like to test on my own custom dataset. Moreover, I already rectify how to make my own dataset in TUM dataset format, but I ...
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### Calculate body speed in m/s with weight in the equation?

UPDATE: I have clarified my question for answerers to better understand what I am asking If I have a flywheel, like the one shown in this image, and I know the torque, weight distribution, and weight. ...
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### digital servo won't seek to angle if delta between current position and target is more than ~15 degrees

My students and I are using a Hiwonder LD-220MG digital servo to position a "shoulder" on a robot. We are seeing a behavior (on every one of these servos that we test) that it won't go ...
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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 ...
81 views

### Can a tablet be slaved to a laptop to act as a wireless usb?

I have built an InMoov Robot. The tablet I got for his controller is too slow. I am currently using a laptop to control him across a usb cable. I want to get rid of the usb cable. I was thinking of ...
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### Effect of platform speed (how fast it is moving) on the quality of SLAM

I want to know how big of on an impact does the speed of the platform on which your sensors are mounted have on the quality of the outcome of a SLAM solution. Are there are any methods that are better ...
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### Collaboration of mobile robot and survaillance camera - classic localization (still) needed?

Just started with the topic of mobile robotics.. so I'm still into concept making and little programming, but have not setup everything or tested at all. I got a (differential) mobile robot (lego ...
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### Graph slam augmentation of Identity Matrix

I am trying to implement GraphSlam. I go through this paper http://robots.stanford.edu/papers/thrun.graphslam.pdf. I have some doubt about the algorithm. I attached a picture with this question My ...
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### How can I get the equations of motion used in webots?

I am trying to use the webots platform for developing controllers. I need the differential equations governing the motion of the robots. How can I get the equations of motion used in webots?
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### Mapping of dynamic environment

I want to do path planning in dynamic environment in which obstacles keep changing. Could you suggest me good path planning algorithm for this? . Is D* algorithm suitable for me to achieve this in ...
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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 ...
56 views

### Extract laser scan from a map and known location

If we have the map of an environment (an occupancy grid for instance) and precisely know the pose of the robot within it. How can one reconstruct what the laser scan should look like at a given ...