Gross motion characteristics of articulated mobile robots with pure rolling capability on smooth uneven surfaces

1999 ◽  
Vol 15 (2) ◽  
pp. 340-343 ◽  
Author(s):  
B.J. Choi ◽  
S.V. Sreenivasan
Keyword(s):  
Mobile Robots ◽  
Pure Rolling ◽  
Motion Characteristics

A Comparative Study on Motion Characteristics of Three Two-Degree-of-Freedom Pointing Mechanisms

2016 ◽  
Vol 8 (2) ◽  
Author(s):  
Jingjun Yu ◽  
Kang Wu ◽  
Guanghua Zong ◽  
Xianwen Kong
Keyword(s):  
Parallel Manipulators ◽  
Degree Of Freedom ◽  
Pure Rolling ◽  
Motion Characteristics ◽  
And Control ◽  
Self Motion ◽  
Tracking Devices ◽  
Two Degree Of Freedom ◽  
Typical Difference ◽  
Composition Theorem

Two-degree-of-freedom (2DOF) pointing mechanisms have been widely used in areas such as stabilized platforms, tracking devices, etc. Besides the commonly used serial gimbal structures, another two types of parallel pointing mechanisms, i.e., spherical parallel manipulators (SPMs) and equal-diameter spherical pure rolling (ESPR) parallel manipulators, are increasingly concerned. Although all these pointing mechanisms have two rotational DOFs, they exhibit very different motion characteristics. A typical difference existing in these three pointing mechanisms can be found from their characteristics of self-motion, also called spinning motion by the authors. In this paper, the spinning motions of three pointing mechanisms are modeled and compared via the graphical approach combined with the vector composition theorem. According to our study, the spinning motion is essentially one component of the moving platform's real rotation. Furthermore, image distortions caused by three spinning motions are identified and distinguished when the pointing mechanisms are used as tracking devices. Conclusions would facilitate the design and control of the pointing devices and potentially improve the measuring accuracy for targets pointing and tracking.

An Algorithm for Real-Time Obstacle Avoidance and Path Planning for Mobile Robots

1991 ◽  
Author(s):  
Y. Lakshmi Srinivas ◽  
Steven N. Kramer
Keyword(s):  
Path Planning ◽  
Mobile Robots ◽  
Real Time ◽  
Obstacle Avoidance ◽  
Control Strategies ◽  
Optimization Techniques ◽  
Previous Knowledge ◽  
Unified Approach ◽  
Real Time Applications ◽  
Motion Characteristics

Abstract This paper presents an extremely fast and reliable sensor-based algorithm that utilizes a combination of optimization techniques and heuristics to accomplish obstacle avoidance and path planning of mobile robots in real-time. This algorithm assumes no previous knowledge of the workspace and is capable of dealing with arbitrarily shaped obstacles with arbitrary motion characteristics. The concept of feasible circle is introduced to determine an obstacle-free subspace around the robot using information which can be obtained from distance sensors. This algorithm employs a unified approach and the modified Lagrange Multiplier method of optimization. A variable penalty, based on the distance of approach is used to keep the robot away from obstacles and the concepts of artificial obstacles and virtual obstacles are introduced to simplify the representation of the known workspace and to control the path of the robot. It is shown that the algorithm is general and can handle concave obstacles, overlapping obstacles, crowded workspaces as well as convex obstacles. The flexibility of the algorithm enables it to be easily integrated with different control strategies. The computational complexity is considerably less than for many existing algorithms, which makes the algorithm attractive for real-time applications. The algorithm is further extended to dynamic obstacles of arbitrary shapes and motion characteristics. Several case studies are presented to illustrate the capabilities of the algorithm.

Kinematics and Force Analysis of Flexible Screw Mechanism for a Worm Robot

2018 ◽  
Vol 10 (6) ◽  
Author(s):  
Yanheng Zhang ◽  
Jian Xu ◽  
Wei Wang
Keyword(s):  
Analytical Solution ◽  
Peristaltic Motion ◽  
Force Analysis ◽  
Hertz Theory ◽  
Curvilinear Motion ◽  
Pure Rolling ◽  
New Type ◽  
Screw Mechanism ◽  
Work Model ◽  
Motion Characteristics

Abstract This paper presents a new type of flexible screw mechanism (FSM), which is composed of a nut, flexible axle, and roller. It can be used in a worm robot to achieve flexible peristaltic motion, as well as curvilinear motion and deformation. This type of FSM uses a roller to decrease the friction. We investigated the transmission principle and the kinematic characteristics of this FSM, established the model of the velocity, acceleration of the roller, characterized the feed motion characteristics of the flexible shaft, and achieved an analytical solution of the flexible shaft's velocity. Furthermore, by considering the position of the pure rolling section of the roller, the spin slide model is proposed based on Hertz theory. To investigate the friction loss between the roller and the flexible axle, we established a friction work model of the entire FSM system. Finally, the motion characteristics of the FSM are evaluated through experiments.

Deployment Control of Wireless Multi-Hop-Relay Mobile Robots Based on Voronoi Partition

2012 ◽  
Vol 132 (3) ◽  
pp. 381-388
Author(s):  
Takaaki Imaizumi ◽  
Hiroyuki Murakami ◽  
Yutaka Uchimura
Keyword(s):  
Mobile Robots ◽  
Voronoi Partition

Control of Mobile Robots by Means of Internet

2006 ◽  
Vol 65 (3) ◽  
pp. 229-241
Author(s):  
S. F. Yatsun ◽  
F. K. Freire ◽  
V. S. Dyshenko ◽  
O. A. Shadrina
Keyword(s):  
Mobile Robots

Modeling of Contact Patch in Dual-Chamber Pneumatic Tires

2018 ◽  
Vol 46 (2) ◽  
pp. 78-92 ◽  
Author(s):  
A. I. Kubba ◽  
G. J. Hall ◽  
S. Varghese ◽  
O. A. Olatunbosun ◽  
C. J. Anthony
Keyword(s):  
Strain Sensors ◽  
Surface Strain ◽  
Wireless Data ◽  
Data Logger ◽  
Dual Chamber ◽  
Piezoelectric Polymer ◽  
Pure Rolling ◽  
Piezoelectric Elements ◽  
Strain Data ◽  
Deformation Patterns

ABSTRACT This study presents an investigation of the inner tire surface strain measurement by using piezoelectric polymer transducers adhered on the inner liner of the tire, acting as strain sensors in both conventional and dual-chamber tires. The piezoelectric elements generate electrical charges when strain is applied. The inner liner tire strain can be found from the generated charge. A wireless data logger was employed to measure and transmit the measured signals from the piezoelectric elements to a PC to store and display the readout signals in real time. The strain data can be used as a monitoring system to recognize tire-loading conditions (e.g., traction, braking, and cornering) in smart tire technology. Finite element simulations, using ABAQUS, were employed to estimate tire deformation patterns in both conventional and dual-chamber tires for pure rolling and steady-state cornering conditions for different inflation pressures to simulate on-road and off-road riding tire performances and to compare with the experimental results obtained from both the piezoelectric transducers and tire test rig.

Sign in / Sign up

Export Citation Format

Share Document