All Questions
Tagged with wheeled-robot mobile-robot
68
questions
0
votes
0
answers
84
views
Wheel submerges into the ground in gazebo
I am currently working on simulating a mobile manipulator in Gazebo using ROS 2, where I am facing this issue. The wheels of the mobile base are being submerged into the ground when I am using kp and ...
- 55
0
votes
1
answer
74
views
How to turn the wheels on a robot that uses ros_control?
I have made a robot with 4 wheels and it uses ros_control. At the moment I can use a python script to make it move forward and backward but I don't know how to make the wheels turn as it only has the <...
- 29
0
votes
0
answers
45
views
Very slow / No rotation of front wheels for an ackermann steering type model
I am trying to simulate a mobile robot with ackermann steering in Gazebo. I have velocity control for rear wheels and steering angle control for front wheels.
I am using ROS2 Humble with Gazebo.
There ...
- 1
0
votes
1
answer
96
views
Mobile robot moves sideways in Rviz, but properly in gazebo
I am currently simulating a mobile robot, and I control its movements using the teleop keyboard node. Upon loading the robot model in both Gazebo and Rviz, the initial orientation appears consistent ...
- 55
0
votes
0
answers
19
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What type of methodology can I use to prove my concept in a journal other than real or simulative implementation?
As I am willing to write a paper based on human-robot interaction where I am willing to suggest some ways to improve robot teleoperation in robotic competition scenarios. I have plans to go through ...
0
votes
1
answer
48
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Instantaneous Center of Rotation of Skid-Steering Mobile Robot
Is there a instantaneous center of rotation (ICR) for 4-wheeled skid steering mobile robot (such as Husky , Pioneer 3-AT) if the center of mass is located at the geometric center of the robot? What if ...
- 11
1
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0
answers
167
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Kinematic model of skid-steering mobile robot (4 wheeled mobile robot)
The kinematic model for skid-steering mobile robot (4 wheeled mobile robot) is
where state vector is $q = (x,y,\theta)$, and $\eta = (v,w)$ is the linear and angular velocity of the robot, and $x_{...
- 11
0
votes
1
answer
78
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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.
$$
\boldsymbol{...
- 1
0
votes
1
answer
160
views
Turning a mecanum wheeled robot at a specific angle i.e 45 degree
I am implementing inverse kinematics for motion control of a robot with four mecanum wheels. However I am not getting how to turn it at specific heading angle(45 degree)? I am using encoders to check ...
- 1
0
votes
1
answer
133
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Move a Three Wheel Omni Robot
I understand this isn't for programming but it's easy to read. I have referenced This for a guide on how to move a 3 wheel omni robot but I have encountered a few problems.
...
- 3
0
votes
1
answer
3k
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4-Wheeled Mobile Robot, Motor-Torque, RPM Calculation
I want the torque, rpm of every motor to be used considering certain factors, in a 4 wheeled robot as you see in the picture below.
Here are the factors affecting motor specifications that I Had ...
1
vote
1
answer
102
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Drive unicycle kinematics equations through the geometry
The unicycle dynamics in discrete-time is given by:
$$
\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 (...
- 189
0
votes
2
answers
50
views
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 ...
- 563
3
votes
1
answer
50
views
Worm gearbox for steering
I'm planning on making a smallish off-road rover (15-25kg net weight) with 4-wheel steering and I was wondering if it'd be a good idea to use (self-locking) worm gearboxes for steering. I've thought ...
- 563
0
votes
1
answer
430
views
error with dimensions in Simulink
I am trying to simulate a cartesian regulator for a unicycle with Simulink and I am having some problems.
My simulink model is the following:
and when I run it I get the following error message:
so ...
- 479
6
votes
0
answers
403
views
Likelihood field sensor model (Probabilistic Robotics, Thrun et al., p.169-174)
I am currently working on the "likelihood field" sensor model (aka "endpoint model") by Thrun et al. (book: Probabilistic Robotics, Thrun et al., p.169-174)
In this context I have ...
- 61
0
votes
1
answer
181
views
Differential Drive Tricycle WMR with active caster wheel
I'm doing some research for my university project and in particular it concerns a functional design project. I thought it would have been possible to design a 3-wheel mobile robot with an active ...
- 3
1
vote
1
answer
2k
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 [...
- 123
2
votes
0
answers
214
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: ...
- 21
1
vote
3
answers
337
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 ...
0
votes
1
answer
3k
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 ...
-1
votes
1
answer
588
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 ...
- 99
0
votes
1
answer
124
views
What robotic skills can I develop when working as a robot operator? [closed]
I find myself very interested to work in the field of robotics though my background is not robotics, I had a degree in Physics, master 1 in Hydrodynamics and this year I have studied just one semester ...
user23478
0
votes
2
answers
65
views
Multiple robots performing a set of tasks (Optimization)
Consider a situation where you have a 'm' number of robots and 'n' number of tasks. Each task is at a different location. What optimization algorithm should I use in order to assign a set of tasks to ...
5
votes
1
answer
4k
views
What is the difference between the pose of a robot and the configuration of a robot?
Do "configuration" and "pose" means the same thing? If not what is the difference?
3
votes
3
answers
121
views
Interference caused by multiple robots during task completion
Suppose there is an area to survey. If we deploy one robot it takes time T to sweep the area. Now if we deploy 2 robots, we would expect it to take time T/2. However in reality, because we are sending ...
- 189
1
vote
0
answers
113
views
TGY-6114MD Servo motor needs push to start
I currently have an inspection robot deployed in a remote part of Africa that has a failing Turnigy TGY-6114MD servo. The issue appeared randomly. The servo won't respond to commands unless given a ...
- 11
0
votes
1
answer
679
views
Omni vs mecanum wheels for drawing robot
I'm designing a mobile robot which will have to draw some lines (straight and/or curly) on the floor while it moves.
The floor will always be flat with almost no obstacles.
The robot will have four ...
- 123
0
votes
1
answer
121
views
Path planning of wheeled robot [duplicate]
let's say the robot Looks like this (an usual robot arm with 4 wheels) :
In this case as far as I know, the idea of path planning is just to compare the actual position x with the desired position ...
- 324
2
votes
0
answers
95
views
Create path with minimum curvature for Ackerman drive
I'm trying to create a trajectory between two given poses for an Ackerman drive.
The poses are defined as follows:
Current Pose
position $(x_0, y_0)$
rotation on z-axis $\theta_0$
Final Pose
...
- 141
1
vote
2
answers
153
views
sampling algorithms in motion planning and local minima
I am trying to run RRT algorithm for motion planning for a quadrotor. The quadrotor ends up sometimes in corners without reaching the goal. I realized from sources online, that it is due to local ...
- 319
1
vote
0
answers
317
views
How does one setup an ESC to drive a wheel-hub motor?
I have 2x 350W wheel-hub motors taken from a self-balancing scooter, or hoverboard. My intention is to use the two of them to drive a homemade R2-D2. However, some difficulties have been encountered ...
user17183
0
votes
1
answer
56
views
How Do You Program the SR04 Ultrasonic Sensor?
Dear Robotics Community,
I am participating in a Robotics tourney that will start in a few weeks. The challenge I signed up for is to deliver and dump ping pong balls to a box. I already have my ...
3
votes
2
answers
837
views
Motion planning and robot controlling
I am stuck with understanding how can I make my robot move along planned path. For instance, if we have a grid map of an environment and applied, for example, A* to plan a path then after that we have ...
- 297
0
votes
2
answers
138
views
Permanent Magnet DC Motor Calcuations
I have to determine speed and torque suitable for my combat robot.
I've done some calculations and I need to know whether they're right or not (because they don't seem to be right).
Suppose I have ...
- 101
0
votes
1
answer
71
views
Is there any robot stability control equation that describes the relation between velocity of the robot and its orientation?
Let’s assume at time t a moving robot (e.g. PIONEER 3-DX) changes it’s steering angle by $25^{\circ}$. Obviously, in order to maintain stability and avoid overturning, the robot must reduce its ...
- 31
1
vote
1
answer
3k
views
Implementing pure pursuit problem in robot navigation? [closed]
I would like to implement pure pursuit waypoints navigation. we know that,
look ahead distance=look ahead gain*vehicle forward velocity
How can I calculate look ahead velocity gain/look ahead gain?
...
- 21
1
vote
2
answers
244
views
Choosing motor to buy after calculations
I am building a two wheeled robot which will have:
max speed of 10km/h and acceleration of 0.5m/s²
can climb 12° slopes
weighs at most 30 kg
wheel diameter is 50cm
By doing the calculations myself, ...
- 35
0
votes
1
answer
73
views
Meaning of symbol, 'curly N' in the equation of Linear Gaussian system dynamics
In the article of Topological Based Representation(Page no. 12), the equation of the Linear Gaussian system dynamics is given as
In above equation what is the meaning of 'curly N'?
- 417
2
votes
1
answer
59
views
Meaning of 'sign' in Writhe Matrix
Following is the equation of Writhe matrix from the article Topology based Representation(page no. 6).
What is the meaning of 'sign' in the second part of this equation? I am not sure if this is some ...
- 417
3
votes
2
answers
891
views
Difference between g-value and rhs-value in Lifelong Planning A*
What is the difference between g-value and rhs-value of Lifelong Planning A* algorithm?
According to this link, D* Lite, g(s) directly correspond to the
g-values of an A* search, i.e. g(s) = g(s') + ...
- 417
2
votes
3
answers
5k
views
How to find kinematics of differential drive caster robot?
I'm working on a little project where I have to do some simulations on a small robot.
I my case I'm using a differential-drive robot as one of the wheels of a bigger robot platform (which has two ...
- 153
0
votes
1
answer
2k
views
How can I measure the actual speed and distance traveled of the robot with an external setup? [closed]
Good day to all.
First of all, I'd like to clarify that the intention of this question is not to solve the localization problem that is so popular in robotics. However, the purpose is to gather ...
- 311
1
vote
2
answers
357
views
How would I replicate a tank/zero-turn steering system in a small robotic vehicle?
I'm working on a project that requires me to build a small vehicle (footprint of ~ 14 x 14 inches, less than 6.5 pounds) that can traverse sand. For the steering system, I was thinking of replicating ...
user10804
5
votes
1
answer
11k
views
How to program a three wheel Omni?
I have created a three wheeled omni robot like the diagram below. Now I am unsure of how to program it. I want to use a single joystick so one x and one y value. The values for x and y are between -1 ...
- 155
4
votes
1
answer
198
views
Sensors' field of view in car driving
I want to develop an autonomous driving RC car. For detecting obstacles, I plan to mount 3-5 ultrasonic sensors in the front and in the back the car. What is the minimum necessary combined field of ...
- 155
1
vote
1
answer
1k
views
Torque of coreless DC micro motor
I would like to build a small two-wheeled robot similar to the one shown here.
In order to keep the robot small, I intend to use two coreless micro motors like the one shown bellow. The power source ...
- 113
1
vote
0
answers
163
views
Angles in a Rocker bogie system
How do you select the following two angles in the design of a Rocker bogie system:
Angle between two arms of the main rocker, and;
Angle between two arms in the bogie.
- 111
1
vote
0
answers
61
views
Heavy omnidirectional platform suspension
I'm planning to build an omnidirectional platform that will support about 180kg robotic arm. The platform will be equipped in meccanum wheels. I would like to have some kind of suspension to avoid ...
- 953
2
votes
1
answer
741
views
Rocker bogie suspension system - pitch angle
What does this sentence mean :
"The chassis maintains the average pitch angle of both rockers."
Put in other words, " the pitching angle of the chassis is the average of the pitch angles of the two ...
- 111