Actuator Array Manipulation Using Low Resolution Local Sensing

2014 ◽  
Author(s):  
Deepak Parajuli ◽  
Mark D. Bedillion ◽  
Randy C. Hoover
Keyword(s):  
Degrees Of Freedom ◽  
Accurate Method ◽  
Distributed Sensing ◽  
Object A ◽  
Distributed Manipulation ◽  
Simulink Model ◽  
Manipulation System ◽  
Position And Orientation ◽  
To Come ◽  
Two Degree Of Freedom

An actuator array is a planar distributed manipulation system that uses multiple two degree-of-freedom actuators to manipulate objects with three degrees of freedom (x, y and θ). This paper presents an accurate method of estimating position and orientation of an object using local sensing and communication. In this method, each of the distributed modules contains a number of binary sensors, weight sensors, and two planar actuators. The binary sensors combined together give a binary image and analog sensors in each module combined together form a grayscale image representation of the weight distribution of the object under manipulation. Additive normalization has been used to combine binary and grayscale distributed sensing images together to come up with increased precision estimates of the position and orientation of an object. A distributed sensing simulation has been developed in Simulink and the effectiveness of this method has been verified for rectangular and circular objects using the Simulink model.

Distributed Sensing in Actuator Array Manipulation

2013 ◽  
Author(s):  
Mark D. Bedillion ◽  
Deepak Parajuli ◽  
Randy C. Hoover
Keyword(s):  
Degrees Of Freedom ◽  
Binary Image ◽  
Distributed Sensing ◽  
Distributed Manipulation ◽  
Actuator Arrays ◽  
Sensor Information ◽  
Position And Orientation ◽  
Binary Object ◽  
Two Degree Of Freedom ◽  
Three Degrees Of Freedom

Actuator arrays are planar distributed manipulation systems that use multiple two degree-of-freedom actuators to manipulate objects with three degrees of freedom (x, y, and θ). This paper describes methods of sensing the position and orientation of objects on an actuator array using only binary object sensors at each actuator. The object sensor information, when combined, forms a binary image of the object which may be processed to recover object pose. The methods’ effectiveness for rectangular objects is verified via simulation.

Actuator Array Dynamics Incorporating Actuator Inertia

2013 ◽  
Author(s):  
Mark D. Bedillion
Keyword(s):  
Degrees Of Freedom ◽  
Friction Model ◽  
Object Motion ◽  
Prior Work ◽  
Control Laws ◽  
Distributed Manipulation ◽  
Actuator Arrays ◽  
Simulation Results ◽  
Two Degree Of Freedom ◽  
Three Degrees Of Freedom

Actuator arrays are planar distributed manipulation systems that use multiple two degree-of-freedom actuators to manipulate objects with three degrees of freedom (x, y, and θ). Prior work has discussed actuator array dynamics while neglecting the inertia of the actuators; this paper extends prior work to the case of non-negligible actuator inertia. The dynamics are presented using a standard friction model incorporating stiction. Simulation results are presented that show object motion under previously derived control laws.

scholarly journals Nonlinear Behavior of a Magnetic Bearing System

1995 ◽  
Vol 117 (3) ◽  
pp. 582-588 ◽  
Author(s):  
L. N. Virgin ◽  
T. F. Walsh ◽  
J. D. Knight
Keyword(s):  
Degrees Of Freedom ◽  
Initial Conditions ◽  
Nonlinear Behavior ◽  
Analytical Techniques ◽  
Magnetic Bearing ◽  
Forced Response ◽  
The Mathematical Model ◽  
Two Degree Of Freedom ◽  
Sensitivity To Initial Conditions ◽  
Bearing System

This paper describes the results of a study into the dynamic behavior of a magnetic bearing system. The research focuses attention on the influence of nonlinearities on the forced response of a two-degree-of-freedom rotating mass suspended by magnetic bearings and subject to rotating unbalance and feedback control. Geometric coupling between the degrees of freedom leads to a pair of nonlinear ordinary differential equations, which are then solved using both numerical simulation and approximate analytical techniques. The system exhibits a variety of interesting and somewhat unexpected phenomena including various amplitude driven bifurcational events, sensitivity to initial conditions, and the complete loss of stability associated with the escape from the potential well in which the system can be thought to be oscillating. An approximate criterion to avoid this last possibility is developed based on concepts of limiting the response of the system. The present paper may be considered as an extension to an earlier study by the same authors, which described the practical context of the work, free vibration, control aspects, and derivation of the mathematical model.

A Model of the Human Spine: Forward and Inverse Kinematics

1992 ◽  
Author(s):  
Sunil Kumar Agrawal ◽  
Siyan Li ◽  
Glen Desmier
Keyword(s):  
Range Of Motion ◽  
Inverse Kinematics ◽  
Degrees Of Freedom ◽  
Kinematic Model ◽  
Joint Angles ◽  
Human Spine ◽  
Forward And Inverse Kinematics ◽  
Position And Orientation ◽  
Three Degrees Of Freedom ◽  
Adjacent Vertebra

Abstract The human spine is a sophisticated mechanism consisting of 24 vertebrae which are arranged in a series-chain between the pelvis and the skull. By careful articulation of these vertebrae, a human being achieves fine motion of the skull. The spine can be modeled as a series-chain with 24 rigid links, the vertebrae, where each vertebra has three degrees-of-freedom relative to an adjacent vertebra. From the studies in the literature, the vertebral geometry and the range of motion between adjacent vertebrae are well-known. The objectives of this paper are to present a kinematic model of the spine using the available data in the literature and an algorithm to compute the inter vertebral joint angles given the position and orientation of the skull. This algorithm is based on the observation that the backbone can be described analytically by a space curve which is used to find the joint solutions..

Alternative Inverse Kinematic Equations for General RRP and RRR Regional Structures of Manipulators

1996 ◽  
Author(s):  
Peregrine E. J. Riley
Keyword(s):  
Degrees Of Freedom ◽  
Joint Angle ◽  
Inverse Kinematic ◽  
Intersection Point ◽  
Degree Polynomial ◽  
Six Degrees Of Freedom ◽  
Common Intersection ◽  
Position And Orientation ◽  
Spatial Positioning ◽  
Orientational Structure

Abstract Many manipulators with six degrees of freedom are constructed with two distinct sections, a regional structure for spatial positioning, and an orientational structure having a common intersection point for the joint axes. With this arrangement, inverse kinematic solutions for position and orientation may be found separately. While solutions for general three link manipulators have been available since the work of Pieper in 1969, this paper presents new forms of the inverse kinematic equations for general RRP and RRR regional structures. Cartesian coordinates of the F-surface (generated by movement of the outer two joints) together with the outer joint angle are used as the equation variables. In addition, a second degree polynomial approxiamation of the equation may be used for quick iteration to a solution. It is hoped that these new equations will be useful by themselves and in workspace regions where solutions using equations in terms of the joint variables are numerically inaccurate or impossible.

An accurate method to include lubrication forces in numerical simulations of dense Stokesian suspensions

2015 ◽  
Vol 769 ◽  
pp. 369-386 ◽  
Author(s):  
A. Lefebvre-Lepot ◽  
B. Merlet ◽  
T. N. Nguyen
Keyword(s):  
Short Range ◽  
Degrees Of Freedom ◽  
Computational Cost ◽  
Parameter Tuning ◽  
Accurate Method ◽  
Spherical Particles ◽  
Particle Model ◽  
Stokesian Dynamics ◽  
New Feature ◽  
The Many

We address the problem of computing the hydrodynamic forces and torques among $N$ solid spherical particles moving with given rotational and translational velocities in Stokes flow. We consider the original fluid–particle model without introducing new hypotheses or models. Our method includes the singular lubrication interactions which may occur when some particles come close to one another. The main new feature is that short-range interactions are propagated to the whole flow, including accurately the many-body lubrication interactions. The method builds on a pre-existing fluid solver and is flexible with respect to the choice of this solver. The error is the error generated by the fluid solver when computing non-singular flows (i.e. with negligible short-range interactions). Therefore, only a small number of degrees of freedom are required and we obtain very accurate simulations within a reasonable computational cost. Our method is closely related to a method proposed by Sangani & Mo (Phys. Fluids, vol. 6, 1994, pp. 1653–1662) but, in contrast with the latter, it does not require parameter tuning. We compare our method with the Stokesian dynamics of Durlofsky et al. (J. Fluid Mech., vol. 180, 1987, pp. 21–49) and show the higher accuracy of the former (both by analysis and by numerical experiments).

scholarly journals Proposal and evaluation of a tablet-based tool for 3D virtual environments

2014 ◽  
Vol 4 (2) ◽  
pp. 1
Author(s):  
Daniel Medeiros ◽  
Felipe Carvalho ◽  
Lucas Teixeira ◽  
Priscilla Braz ◽  
Alberto Raposo ◽  
...  
Keyword(s):  
Virtual Environments ◽  
Degrees Of Freedom ◽  
Specific Interaction ◽  
System Control ◽  
3D Interaction ◽  
Additional Information ◽  
Manipulation System ◽  
Study Case ◽  
Immersive Environment ◽  
3D Virtual Environments

The introduction of embedded sensors in smartphones and tablets allowed the use of these devices to interact with virtual environments. These devices also have the possibility of including additional information and performing naturally non-immersive tasks. This work presents a 3D interaction tablet-based tool, which allows the aggregation of all major 3D interaction tasks, such as navigation, selection, manipulation, system control and symbolic input. This tool is for generalpurpose systems, as well as, engineering applications. Generally this kind of application uses specific interaction devices with four or more degrees of freedom and a common keyboard and mouse for tasks that are naturally non-immersive, such as symbolic input (e.g., text or number input). This article proposes a new tablet-based device that can perform all these major tasks in an immersive environment. It also presents a study case of the use of the device and some user tests.

Design and Fabrication of a Multi-Functional Nanomanipulator

2009 ◽  
Vol 419-420 ◽  
pp. 21-24
Author(s):  
Ming Chang ◽  
Chia Hung Lin ◽  
Chung Po Lin ◽  
Juti Rani Deka
Keyword(s):  
Degrees Of Freedom ◽  
Electrical Characterization ◽  
The Body ◽  
Rapid Expansion ◽  
Nano Materials ◽  
Nano Fabrication ◽  
Permissible Range ◽  
Manipulation System

With rapid expansion of nanotechnology, microminiaturization has become imperative in the field of micro/nano fabrication. A nanomanipulation system with high degrees of freedom that can perform nanomachining, nanofabrication and mechanical/electrical characterization of nanoscale objects inside a scanning electron microscope (SEM) is presented. The manipulation system consists of several individual operating units each having three linear stages and one rotational stage. The body of the manipulator is designed using the idea of superposition. Each operating unit can move in the permissible range of SEM’s vacuum chamber and can increase or decrease the number of units according to the requirement. Experiments were executed to investigate the in-situ electrical resistance of nano materials.

Harmonic Oscillations of Nonlinear Two-Degree-of-Freedom Systems

1955 ◽  
Vol 22 (1) ◽  
pp. 107-110
Author(s):  
T. C. Huang
Keyword(s):  
Nonlinear System ◽  
Degrees Of Freedom ◽  
Forced Oscillations ◽  
Viscous Damping ◽  
Free Oscillations ◽  
Response Curves ◽  
Harmonic Oscillations ◽  
Restoring Force ◽  
Nonlinear Restoring Force ◽  
Two Degree Of Freedom

Abstract In this paper an investigation is made of equations governing the oscillations of a nonlinear system in two degrees of freedom. Analyses of harmonic oscillations are illustrated for the cases of (1) the forced oscillations with nonlinear restoring force, damping neglected; (2) the free oscillations with nonlinear restoring force, damping neglected; and (3) the forced oscillations with nonlinear restoring force, small viscous damping considered. Amplitudes of oscillations and frequency equations are derived based on the mathematically justified perturbation method. Response curves are then plotted.

scholarly journals Applying Touchscreen Based Navigation Techniques to Mobile Virtual Reality with Open Clip-On Lenses

Electronics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1448 ◽  
Author(s):  
Youngwon Ryan Kim ◽  
Hyeonah Choi ◽  
Minwook Chang ◽  
Gerard J. Kim
Keyword(s):  
Virtual Reality ◽  
Degrees Of Freedom ◽  
Head Rotation ◽  
Display Device ◽  
Interaction Technique ◽  
Six Degrees Of Freedom ◽  
3D Space ◽  
To Come ◽  
3D Applications ◽  
Navigation Method

Recently, a new breed of mobile virtual reality (dubbed as “EasyVR” in this work), has appeared in the form of conveniently clipping on a non-isolating magnifying lenses on the smartphone, still offering a reasonable level of immersion to using the isolated headset. Furthermore, such a form factor allows the fingers to touch the screen and select objects quite accurately, despite the finger(s) being seen unfocused over the lenses. Many navigation techniques have existed for both casual smartphone 3D applications using the touchscreen and immersive VR environments using the various controllers/sensors. However, no research has focused on the proper navigation interaction technique for a platform like EasyVR which necessitates the use of the touchscreen while holding the display device to the head and looking through the magnifying lenses. To design and propose the most fitting navigation method(s) with EasyVR, we mixed and matched the conventional touchscreen based and headset oriented navigation methods to come up with six viable navigation techniques—more specifically for selecting the travel direction and invoking the movement itself—including the use of head-rotation, on-screen keypads/buttons, one-touch teleport, drag-to-target, and finger gestures. These methods were experimentally compared for their basic usability and the level of immersion in navigating in 3D space with six degrees of freedom. The results provide a valuable guideline for designing/choosing the proper navigation method under different navigational needs of the given VR application.

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