scholarly journals Suboptimal Omnidirectional Wheel Design and Implementation

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 865
Author(s):  
Jordi Palacín ◽  
David Martínez ◽  
Elena Rubies ◽  
Eduard Clotet
Keyword(s):  
Mobile Robot ◽  
Suspension System ◽  
Final Conclusion ◽  
Manufacturing Cost ◽  
Omnidirectional Mobile Robot ◽  
Planar Surfaces ◽  
Motion System ◽  
Contact Discontinuities ◽  
Passive Suspension System ◽  
Omnidirectional Wheels

The optimal design of an omnidirectional wheel is usually focused on the minimization of the gap between the free rollers of the wheel in order to minimize contact discontinuities with the floor in order to minimize the generation of vibrations. However, in practice, a fast, tall, and heavy-weighted mobile robot using optimal omnidirectional wheels may also need a suspension system in order to reduce the presence of vibrations and oscillations in the upper part of the mobile robot. This paper empirically evaluates whether a heavy-weighted omnidirectional mobile robot can take advantage of its passive suspension system in order to also use non-optimal or suboptimal omnidirectional wheels with a non-optimized inner gap. The main comparative advantages of the proposed suboptimal omnidirectional wheel are its low manufacturing cost and the possibility of taking advantage of the gap to operate outdoors. The experimental part of this paper compares the vibrations generated by the motion system of a versatile mobile robot using optimal and suboptimal omnidirectional wheels. The final conclusion is that a suboptimal wheel with a large gap produces comparable on-board vibration patterns while maintaining the traction and increasing the grip on non-perfect planar surfaces.

Calibration of omnidirectional wheeled mobile robots: method and experiments

Robotica ◽  
2013 ◽  
Vol 31 (6) ◽  
pp. 969-980 ◽  
Author(s):  
Yaser Maddahi ◽  
Ali Maddahi ◽  
Nariman Sepehri
Keyword(s):  
Mobile Robot ◽  
Mobile Robots ◽  
Systematic Errors ◽  
Wheeled Mobile Robot ◽  
Wheeled Mobile Robots ◽  
Omnidirectional Mobile Robot ◽  
Position Errors ◽  
Positioning Errors ◽  
Surface Irregularities ◽  
Omnidirectional Wheels

SUMMARYOdometry errors, which occur during wheeled mobile robot movement, are inevitable as they originate from hard-to-avoid imperfections such as unequal wheels diameters, joints misalignment, backlash, slippage in encoder pulses, and much more. This paper extends the method, developed previously by the authors for calibration of differential mobile robots, to reduce positioning errors for the class of mobile robots having omnidirectional wheels. The method is built upon the easy to construct kinematic formulation of omnidirectional wheels, and is capable of compensating both systematic and non-systematic errors. The effectiveness of the method is experimentally investigated on a prototype three-wheeled omnidirectional mobile robot. The validations include tracking unseen trajectories, self-rotation, as well as travelling over surface irregularities. Results show that the method is very effective in improving position errors by at least 68%. Since the method is simple to implement and has no assumption on the sources of errors, it should be considered seriously as a tool for calibrating omnidirectional mobile having any number of wheels.

scholarly journals Criteria of Motion Without Slipping for an Omnidirectional Mobile Robot

2021 ◽  
Vol 17 (4) ◽  
pp. 527-546
Author(s):  
I. S. Mamaev ◽  
◽  
A. A. Kilin ◽  
Yu. L. Karavaev ◽  
V. A. Shestakov ◽  
...  
Keyword(s):  
Mobile Robot ◽  
Euler Equations ◽  
Elementary Geometry ◽  
Supporting Surface ◽  
Dynamical Equations ◽  
Omnidirectional Mobile Robot ◽  
Angular Velocities ◽  
Reaction Forces ◽  
Position And Orientation ◽  
Omnidirectional Wheels

In this paper we present a study of the dynamics of a mobile robot with omnidirectional wheels taking into account the reaction forces acting from the plane. The dynamical equations are obtained in the form of Newton – Euler equations. In the course of the study, we formulate structural restrictions on the position and orientation of the omnidirectional wheels and their rollers taking into account the possibility of implementing the omnidirectional motion. We obtain the dependence of reaction forces acting on the wheel from the supporting surface on the parameters defining the trajectory of motion: linear and angular velocities and accelerations, and the curvature of the trajectory of motion. A striking feature of the system considered is that the results obtained can be formulated in terms of elementary geometry.

scholarly journals Front and Back Movement Analysis of a Triangle-Structured Three-Wheeled Omnidirectional Mobile Robot by Varying the Angles between Two Selected Wheels

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
A. P. Mohanraj ◽  
A. Elango ◽  
Mutra Chanakya Reddy
Keyword(s):  
Mobile Robot ◽  
Design Research ◽  
Movement Analysis ◽  
Forward Direction ◽  
Reverse Direction ◽  
Angle Variable ◽  
Omnidirectional Mobile Robot ◽  
Linear Movement ◽  
Omnidirectional Wheels ◽  
Cement Surface

Omnidirectional robots can move in all directions without steering their wheels and it can rotate clockwise and counterclockwise with reference to their axis. In this paper, we focused only on front and back movement, to analyse the square- and triangle-structured omnidirectional robot movements. An omnidirectional mobile robot shows different performances with the different number of wheels and the omnidirectional mobile robot’s chassis design. Research is going on in this field to improve the accurate movement capability of omnidirectional mobile robots. This paper presents a design of a unique device of Angle Variable Chassis (AVC) for linear movement analysis of a three-wheeled omnidirectional mobile robot (TWOMR), at various angles (θ) between the wheels. Basic mobility algorithm is developed by varying the angles between the two selected omnidirectional wheels in TWOMR. The experiment is carried out by varying the angles (θ= 30°, 45°, 60°, 90°, and 120°) between the two selected omniwheels and analysing the movement of TWOMR in forward direction and reverse direction on a smooth cement surface. Respectively, it is compared to itself for various angles (θ), to get its advantages and weaknesses. The conclusion of the paper provides effective movement of TWOMR at a particular angle (θ) and also the application of TWOMR in different situations.

Testing the Accuracy of the Trajectory Ride for Omnidirectional Mobile Robot Odin

2015 ◽  
Vol 772 ◽  
pp. 500-505 ◽  
Author(s):  
Matěj Gala ◽  
Václav Krys ◽  
Tomáš Kot
Keyword(s):  
Mobile Robot ◽  
Stair Climbing ◽  
Mechanical Parameters ◽  
Omnidirectional Mobile Robot ◽  
Trajectory Following ◽  
Omnidirectional Wheels

This article describes the process of designing and testing the accuracy of trajectory following for omnidirectional mobile robot Odin. It explains the relation between mobile robotic stair climbing system with shaped wheels and omnidirectional wheels, which are used together in a combined locomotive system. It is presented by the conception study only on account of realization of the simplified chassis with the omnidirectional wheels for testing mechanical parameters and the accuracy of the trajectory ride. The omnidirectional mobile robot Odin was built based on a simplified chassis with omnidirectional wheels and with the modular manipulator Schunk mounted on top. The article concludes with a description and comparison of the achieved results by testing the accuracy of the trajectory ride for the simplified chassis and for the omnidirectional mobile robot Odin.

Simultaneous tracking and stabilization of an omnidirectional mobile robot in polar coordinates: a unified control approach

Robotica ◽  
2009 ◽  
Vol 27 (3) ◽  
pp. 447-458 ◽  
Author(s):  
Hsu-Chih Huang ◽  
Ching-Chih Tsai
Keyword(s):  
Mobile Robot ◽  
Feedback Linearization ◽  
Control Method ◽  
Kinematic Model ◽  
Path Following ◽  
Polar Space ◽  
Polar Coordinates ◽  
Control Approach ◽  
Omnidirectional Mobile Robot ◽  
Omnidirectional Wheels

SUMMARYThis paper presents a polar-space kinematics control method to achieve simultaneous tracking and stabilization for an omnidirectional wheeled mobile robot with three independent driving omnidirectional wheels equally spaced at 120° from one another. The kinematic model of the robot in polar coordinates is presented. With the kinematic model, a kinematic control method based on feedback linearization is proposed in order to achieve simultaneous tracking and stabilization. The proposed method is easily extended to address the path following problem. Computer simulations and experimental results are presented to show the effectiveness and usefulness of the proposed control method at slow speeds.

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