Questions tagged [mobile-robot]
A robot which is capable of moving from one place to another, usually of its own volition.
584
questions
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31 views
How to avoid hair entanglement in your robot wheels?
This isn't about any complex math or physics of robots, but rather an annoying practical issue I don't find much information about.
My robot works indoors (house, office) and there's certainly going ...
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13 views
Drone based CV via base station - power requirments
Currently computer vision based inference is impractical on a drone given the significant power draw.
Is connecting a drone to a base station which does CV a viable solution to this issue? Has it been ...
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3answers
31 views
Occupancy grid maps
Why do we take probabilistic approch to model the environment for robots in occupancy grid maps.The assumption is always taken that each cell on the grid map is either free or occupied.So why have ...
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10 views
problem in understanding this part of the RRTx path finding algorithm
this is a paragraph from the paper of the RRTx algorithm
and below it a figure referenced in the paragraph
however the No and Nr nodes types are unclear to me what are they exactly ?
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3answers
36 views
How to avoid false encoder counts due to vibration in robot?
I have a couple of motors on my mobile base other than the drive motors, and they tend to create vibration in the robot. When these motors are turned on, the wheel's encoder ticks increase without any ...
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20 views
Serial communication of IMU and Encoder arduino code
Pls, I need people to help me look at where I am getting it wrong. I test this code on Arduino ide and got the result I wanted but sending it to Matlab through serial communication, I obtained a ...
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1answer
49 views
Do mobile robots use variable transmissions?
I've built a simple robot that can move. I'm using brushless motors. I've realized that at slow speeds the motors pull a lot of current. I didn't understand the power / current / efficiency charts ...
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0answers
18 views
Degree of maneuverability mobile robot
According to the traditional kinematic theory for mobile robots [1][2] a mobile robot with a steerable wheel and two passive casters presents a $\delta_m=2,\delta_s=1,\delta_M=3$. This is easy to ...
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2answers
31 views
HTTP requestes for Robot Teleoperation
I'm new to this forum so I apologise if I disrespect some rules. I am considering using HTTP requests to control a robot remotely. The design problem I am trying to solve is that I would like to ...
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1answer
31 views
Motion of a mobile platform inaccurate than industrial robot arm
It is known that with a 7DoF industrial you can achieve an accuracy of ~2mm.
However, the motion with a mobile platform is known to be more inaccurate and expensive.
I can follow why the motion is ...
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17 views
Path planning priors in dynamic enviroments
What are the general path priors used when planning in a dynamic environment with people/cars/other robots?
Suppose you don't have a global view of the environment, only a local view around the ...
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23 views
calculate self aligning torque from steering wheel angle
I would like to calculate self aligning torque (SAT) to apply it for a simulating game with Logitech G29 steering wheel, the torque is gonna be inferred from steering wheel angle (plus car motion). I ...
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1answer
44 views
Matlab Simulation using Webots!
I am trying to run this youbot ( sample world) from webots, where the controller is implemented in MATLAB, on running the code it pops out the following error seen in the picture attached. I have also ...
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1answer
37 views
Odometry using wheel encoder with no differential drive
I am currently looking for a way to do odometry using wheel encoders, for a car that has no differential drive. The two rear wheel would rotate at the exact same speed. I have been looking everywhere ...
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17 views
How does a recursive Bayesian depth filter is used to build a map in visual odometry?
I am trying to understand a paper on visual odometry and I am having troubles understanding how a map is generated using a stereo camera as sensor.
The paper I am reading is SVO: Semi-Direct Visual ...
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1answer
24 views
What is the purpose of an empty link without any child elements?
I was looking at a model xacro [urdf] file in a ROS tutorial when I saw:
...
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32 views
How does inverse compositional Lucas–Kanade algorithm work?
I am trying to understand the Lucas–Kanade algorithm since I am reading a paper in which is applied the inverse compositional Lucas–Kanade algorithm, but in order to understand the latter I have to ...
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1answer
45 views
How to PID tune a four wheel robot?
Four wheel mecanum rover with a mass of approximately 50 Kg. Each wheel has a 20:1 gearbox with encoder at the wheel (rather than the motor).
If this was something like a robot arm I would PID tune ...
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1answer
12 views
AC Motors vs Hydraulic motors for skid-steering robot
I'm designing a mobile robot with tracks and skid-steering driving system and I am evaluating whether an electric motor would be better than a hydraulic one.
I did some calculations, the total weight ...
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1answer
38 views
Problem understanding a paper about visual odometry
I am reading the following paper: SVO: Semi-Direct Visual Odometry for Monocular
and Multi-Camera Systems
, and I am having some problem understanding some concepts.
Before starting I have to say ...
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0answers
15 views
Use polynomials to detach number of MPC controls from size of time-horizon?
Model Predictive Control (MPC) works by finding a set of controls $u_0, \dots, u_n$ that minimize a cost function $J$ over a time-horizon $[t, t + T]$. Typically when MPC is used on mobile robots, ...
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2answers
60 views
motion model for forward movement
I thought this is a simple and well known problem and therefore there is a lot of literature. But I'm not able to find the correct keywords to google the answer. Maybe instead of answering the whole ...
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1answer
69 views
Applications of Reinforcement Learning
Many global-control applications of robotics involve incomplete world information and at best can be represented as a POMDP.
Given this, can we really apply RL to most robotics applications? From ...
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1answer
81 views
Extended Kalman filtering for IMU and Encoder
I am trying to fuse IMU and encoder using extended Kalman sensor fusion technique. how do I fuse IMU pitch, roll with the orientation data I obtained from the encoder. Also, how do I use my position x ...
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9 views
Navigation Function : Sphere Spaced Set
The navigation function in a sphere spaced set is given by:
Equation
How do I determine the value of Lambda?
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0answers
58 views
two wheel mobile robot odometry
I am using an encoder to calculate the position and orientation of a mobile robot. The robot has two-wheel and each wheel is attached with an encoder, the result I am getting for my position x,y and ...
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0answers
50 views
What is the definition of the phrase “ego robot”?
What does the phrase "ego robot" mean? I see it used in the context of multi robot systems like in the paper Game Theoretic Motion Planning for Multi-robot Racing by Zijian Wang, Riccardo Spica & ...
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1answer
58 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 ...
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0answers
28 views
Formulas for calculating the passive joints angular velocities
We have the following parallel robot architecture:
Positions of the vectors $u_i, v_i, w_i$, the angles $\theta_i$, angular velocity $\dot{\theta_i}$ and the Jacobian $J$, that mapping vector of ...
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0answers
22 views
Hint regarding Localization & Map Scaling
I just started with mobile robotics. I'm trying to do a collaborative system between a mobile robot and a ceiling camera (Raspberry). They should do all tasks as a "team". Means Calibration, ...
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0answers
63 views
EKF landmark-based help needed
I am new in localization algorithms and EKF is new for me as well. I think that I implemented EKF (the whole code of class is here. I have problems in updating bearing angle of the robot. Basically I ...
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0answers
28 views
How to find the optimal path for a line following maze robot?
First let me explain the problem.
This is a maze made only out of black lines on a white surface. The robot has only a few IR sensors which can sense the position of the line. No other sensory input ...
0
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1answer
56 views
Advantage of Kalman filter in differential drive planar robot
We need to estimate the position and orientation of differential drive robot by using encoders and imu sensor. For this specific case, is there any advantage of using Kalman filter than taking the ...
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3answers
86 views
Arduino for mobile robot
Is it possible to drive the whole mobile differential drive robot with single arduino? Sonar sensor, servo motor, two encoders, two motors, imu, etc. I mean would it give a reasonable performance or ...
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1answer
69 views
Controller algorithm implementation in ROS/Gazebo
I am doing some robotic simulations in ROS/Gazebo and wondering what is the best way (programming-wise since I don't have a CS background) to implement a robot's motion controller.
Here are the ...
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39 views
Use Camera Calibration Matrix without Toolbox
I am doing this little project where try to calibrate a Raspberry Pi Camera. I use Matlab and I do not want to use the Calibration Toolbox (!). The algorithm I use is the direct linear transformarion ...
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1answer
85 views
How to drive mecanum wheels robot: code or algorithm
I have a robot with four mecanum wheels and I would like to make it move correctly by using a RC transmitter (my controller has two sticks and several buttons, each stick has a proportional range of [...
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0answers
34 views
Are rotary encoders necessary for holonomic mecanum drive?
I'm making a robot which is going to have a holonomic mecanum drive. The doubt that I'm having is that should I use rotary encoders for doing so.
The bot will be manually controlled so would it be ...
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1answer
31 views
Forward kinematics of spherical parallel manipulators with revolute joints
I found an article that can help in my investigations.
Forward kinematics of spherical parallel manipulators with revolute joints
The problem is solved for the following system of vectors, which is ...
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0answers
24 views
Ceiling Camera & robot - SLAM still neded?
I've got a question regarding the topic of SLAM. My composition consists of a mobile robot and a top down looking 2D camera with wide-angle lens. It is comparable to a survaillance camera mounted on ...
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1answer
63 views
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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1answer
38 views
How does scan matching find overlapping regions in two scans?
I have been reading about scan matching and so far I have gathered that scan matching tries to find the transformation (rotation and translation) which leads to the best match between overlapping ...
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0answers
31 views
Robot-telescope prototype controlled by a PC
Has anyone developed mechatronic systems for DIY-telescopes running a PC?
Please share your experience, knowledge and nuances (how you acquired current sensors, speeds, electric motors, about ...
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1answer
72 views
Modeling of Robots
There are mainly two approaches for controlling robots (mobile robots and static robots): 1) working with kinematic equations, controlling joint or wheel speeds , 2) working with dynamic equations and ...
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1answer
59 views
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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0answers
23 views
How do I say if a system is differentially flat?
I am studying mobile robots, and I have encoutered the concept of differentially flat systems. I have seen that if a system is differentially flat, we can identify flat outputs, thanks to which we can ...
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1answer
33 views
Doubt on artificial potential field
I am studying motion planning, and I am focusing on artificial potential fields. I have seen that it consists in having a repulsive field for obstacles, and an attractive field toward the goal.
But ...
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0answers
51 views
When do I do motion planning?
I am studying mobile robots, and I am focusing my attention to the unycicle. I have a doubt concerning the motion planning part. In particular I don't understand when the motion planning is done and ...
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0answers
29 views
Choosing right motors for self-balancing robot [closed]
I’m looking for right motors for my first self-balancing robot.
Design assumptions:
robot height: around 120-200 mm
robot weight: around 600-800 grams
wheels: 80x10 mm or 90x10 mm
battery voltage: ...
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3answers
63 views
I wanna make a raspberry pi car using an RC car. I would like to know if the servo multiplexer is necessary?
So I'm working on a project and it involves making a raspberry pi car, be it from scratch or with the help of can rc car. I chose the latter. Now the problem is I don't really have servo multiplexers ...
