A new method for online identification of the center of mass of spacecraft using multiple accelerometers

2014 ◽  
Vol 229 (1) ◽  
pp. 110-118 ◽  
Author(s):  
Huang He ◽  
Zhou Jun ◽  
Liu Yingying
Keyword(s):  
Center Of Mass ◽  
New Method ◽  
Online Identification

scholarly journals Online diagnosis of supercapacitors using extended Kalman filter combined with PID corrector

2021 ◽  
Vol 12 (3) ◽  
pp. 1521
Author(s):  
Zoubida Bououchma ◽  
Jalal Sabor
Keyword(s):  
Electrochemical Impedance ◽  
New Method ◽  
Specific Power ◽  
Attractive Alternative ◽  
State Of Health ◽  
Energy Storage Devices ◽  
Good Efficiency ◽  
Storage Devices ◽  
Online Identification ◽  
Identification Method

<span>Supercapacitors are electrical energy storage devices with a high specific power density, a long cycle life and a good efficiency, which make them attractive alternative storage devices for various applications. However, supercapacitors are subject to a progressive degradation of their perfor-mance because of aging phenomenon. Therefore, it is very important to be able to estimate their State-of-Health during operation. Electrochemical Impedance Spectroscopy (EIS) is a very recog-nized technique to determine supercapacitors’ state-of-health. However, it requires the interrup-tion of system operation and thus cannot be performed in real time (online). In this paper, a new online identification method is proposed based on extended Kalman observer combined with a complementary PID corrector. The proposed method allows to accurately estimating supercapacitor resistance and capacitance, which are the main indicators of supercapacitor state-of-health. The new online identification method was applied for two voltage/current profiles using two different supercapacitors. The resistance/capacitance estimated by the new method and the conventional EKF were compared with those obtained by an experimental offline method. In comparison with conventional EKF, the capacitance obtained by the new method is significantly more accurate.</span>

scholarly journals Algorithms for the Motion of Randomly Positioned Hexagonal and Square Microparts on a “Smart Platform” with Electrostatic Forces and a New Method for Their Simultaneous Centralization and Alignment

Micromachines ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 874
Author(s):  
Georgia Kritikou ◽  
Nikos Aspragathos ◽  
Vassilis Moulianitis
Keyword(s):  
Collision Avoidance ◽  
Center Of Mass ◽  
Initial Configuration ◽  
New Method ◽  
Electrostatic Forces ◽  
Multiple Electrodes ◽  
Parallel Motion ◽  
Glass Type

In this paper, an approach is proposed for the simultaneous manipulation of multiple hexagonal and square plastic–glass type microparts that are positioned randomly on a smart platform (SP) using electrostatic forces applied by the suitable activation of circular conductive electrodes. First, the statics analysis of a micropart on the SP is presented in detail and the forces and torques that are applied to and around the center of mass (COM) respectively due to the activation of a SP electrode are determined. The “single electrode activation” (SEA) and the “multiple electrodes activations” (MEA) algorithms are introduced to determine the feasible SP electrodes activations for the microparts manipulation considering their initial configuration. An algorithm for the simultaneous handling of multiple microparts is studied considering the collision avoidance with neighboring microparts. An approach is presented for the simultaneous centralization and alignment of the microparts preparing them for their batch parallel motion on the SP. The developed algorithms are applied to a simulated platform and the results are presented and discussed.

A New Method for Completely Force Balancing Simple Linkages

1969 ◽  
Vol 91 (1) ◽  
pp. 21-26 ◽  
Author(s):  
R. S. Berkof ◽  
G. G. Lowen
Keyword(s):  
Center Of Mass ◽  
Time Dependent ◽  
New Method ◽  
Practical Applications ◽  
Mass Distributions ◽  
Linearly Independent ◽  
Planar Linkages

A new method, herein referred to as the “Method of Linearly Independent Vectors,” is shown to permit the complete force balancing of certain planar linkages. This method consists of writing the equation describing the position of the total mechanism center of mass in such a way that the coefficients of the time-dependent terms may be set equal to zero. In this way, the total center of mass can be made stationary, and the shaking force vanishes. Derivations as well as practical applications are shown for four-bar and six-bar linkages with arbitrary link mass distributions.

Complete Force Balancing of Spatial Linkages

1971 ◽  
Vol 93 (2) ◽  
pp. 620-626 ◽  
Author(s):  
Roger E. Kaufman ◽  
George N. Sandor
Keyword(s):  
Center Of Mass ◽  
Time Dependent ◽  
New Method ◽  
Operator Equations ◽  
Spatial Linkages ◽  
The Given

A new method permits the complete force balancing of spatial linkages such as the RSSR and RSSP mechanisms. Operator equations are written describing the location of the center of mass for the given mechanism. The coefficients of the time-dependent terms are set to zero by properly locating the mass centers of selected links. As a result, the location of the total center of mass is invariant and there is no resultant shaking force.

Complete Balancing of Multicylinder Engines Without Requiring Harmonic Balancers

1995 ◽  
Author(s):  
Cemil Bagci
Keyword(s):  
Angular Momentum ◽  
Center Of Mass ◽  
New Method ◽  
Harmonic Force ◽  
Vector Method ◽  
Numerical Examples ◽  
Single Cylinder ◽  
Linearly Independent ◽  
Phase Angles ◽  
Shaking Moment

Abstract Presently used balancing methods for multicylinder engines and pumps are for partial balancing. As a result the complete shaking force, shaking torque, and shaking moment balancings of engines require the use of harmonic force and harmonic torque and moment balancers. This article presents a new method for complete shaking force and shaking moment balancing of multicylinder engines that requires no harmonic balancers. This is achieved by keeping the total center of mass of each slider crank loop stationary, where the design equations are developed using a linearly independent mass vector method. Balancing the shaking force also balances the shaking moment. Shaking torque is balanced by eliminating the angular momentum of each mechanism loop and by arranging the phase angles of the crank throws. Four-, six-, and eight-cylinder engines are balanced in the numerical examples given. Two methods of completely balancing single-cylinder engines are also given.

Null Correlation Method for Estimation of the Primary Energies of Cosmic Ray Jets

1973 ◽  
Vol 51 (8) ◽  
pp. 804-813
Author(s):  
Robert E. Streitmatter
Keyword(s):  
Monte Carlo ◽  
Center Of Mass ◽  
Monte Carlo Model ◽  
Correlation Method ◽  
Cosmic Ray ◽  
High Energy ◽  
Cloud Chamber ◽  
New Method ◽  
Cosmic Ray Interactions

A new method for estimating the center of mass of high energy cosmic ray interactions is introduced and tested with a simple Monte Carlo model and a small number of cloud chamber jets.

Research on Fast Locating Solder Joint on Fully-Automatic LED Wire Bonder

2011 ◽  
Vol 105-107 ◽  
pp. 1827-1830
Author(s):  
Zhi Chao Huang ◽  
Mu Liu ◽  
Hua Dong Liu ◽  
Xing Ming Fan ◽  
Yi Zhong
Keyword(s):  
Solder Joint ◽  
Center Of Mass ◽  
Window Size ◽  
Adaptive Threshold ◽  
New Method ◽  
Median Filtering ◽  
Adaptive Window ◽  
Grey Scale ◽  
Fully Automatic ◽  
Potential Area

A new method is put forward to positioning solder joints on fully-automatic LED wire bonder. In the method, the image of a LED micro-chip is first processed with GPU by median filtering based on average and adaptive window size. Then the potential areas of the micro-chip are determined by the algorithm of adaptive threshold for image. These potential areas are stored in groups according to distances. The best potential area of each group is screened out in terms of symmetrical features of grey scale after that it is a weighted process. Finally, the LED micro-chip solder joint is precisely located by calculating the center of mass. The results show that the proposed method is fast, accurate, effective, suitable for automation, and has no requirement to the consistency of the shape of LED micro-chips.

scholarly journals Discover Your Potential: The Influence of Kinematics on a Muscle’s Ability to Contribute to the Sit-to-Stand Transfer

2021 ◽  
Author(s):  
Sarah A. Roelker ◽  
Laura C. Schmitt ◽  
Ajit M.W. Chaudhari ◽  
Robert A. Siston
Keyword(s):  
Young Adults ◽  
Center Of Mass ◽  
Joint Kinematics ◽  
New Method ◽  
Whole Body ◽  
Muscle Strengthening ◽  
Sit To Stand ◽  
Vertical Support ◽  
Anterior Pelvic Tilt ◽  
Body Center

AbstractExisting methods for estimating how individual muscles contribute to a movement require extensive time and experimental resources. In this study we developed an efficient method for determining how changes to lower extremity joint kinematics affect the potential of individual muscles to contribute to whole-body center-of-mass vertical (support) and anteroposterior (progression) accelerations. A 4-link 2-dimensional model was used to assess the effect of kinematic changes on muscle function. Joint kinematics were systematically varied throughout ranges observed during the momentum transfer phase of the sit-to-stand transfer. Each muscle’s potential to contribute to support and progression was computed and compared to simulated potentials estimated by traditional dynamic simulation methods for young adults and individuals with knee osteoarthritis (KOA). The new method required 4-10s to compute muscle potentials per kinematic state and computed potentials were consistent with simulated potentials. The new method identified differences in muscle potentials between groups due to kinematic differences, particularly decreased anterior pelvic tilt in young adults, and revealed kinematic and muscle strengthening modifications to increase support. The methods presented provide an efficient, systematic approach to evaluate how joint kinematic adjustments alter a muscle’s ability to contribute to movement and can identify potential sources of pathologic movement and rehabilitation strategies.

scholarly journals Postural perturbation induced by electrical stimulation; A new approach to examine the mechanism of falling

2021 ◽  
Author(s):  
Behdad Tahayori ◽  
Bahman Tahayori ◽  
Alireza Mehdizadeh ◽  
David M. Koceja
Keyword(s):  
Balance Control ◽  
Center Of Mass ◽  
Analytical Techniques ◽  
H Reflex ◽  
New Method ◽  
Clear Understanding ◽  
Postural Perturbation ◽  
New Approach ◽  
M Wave ◽  
Gastrocnemius Muscles

AbstractBackgroundFalling is a major cause of disability and death among elderly people. Therefore, a clear understanding of fall mechanism is necessary for providing preventative and treatment methods. Several fall simulation protocols have been introduced to study lost of balance in a laboratory setting.New MethodWe have explained and examined a new method to induce a sudden perturbation on standing posture to provide an insight into the mechanism of falling. The method comprises eliciting an H-reflex protocol while subjects are standing which produces a contraction in soleus and gastrocnemius muscles. We have also defined analytical techniques to provide biomarkers of balance control during perturbation. The method is easy to implement and interpret. The H-reflex or M-wave can be elicited unilaterally or bilaterally causing a forward or sideway perturbation. The vector analysis and the Equilibrium Point calculations defined here can quantify the amplitude, direction, and evolution of the perturbation.ResultsWe tested this method on a group of healthy individuals and observed clear patterns of loss of balance due to stimulation. Direction and magnitude of deviation was manifested through the reconstructed vectors, with bilateral stimulation causing the largest perturbation.Comparison and conclusionThe resultant plantarflexion torque is reminiscent of tripping over an obstacle and triggers corrective reactions to restore balance. Therefore, it is more similar to an internal perturbation. Mechanical perturbations to the torso cause a displacement in center of mass (COM) and trigger a cascade of mechanisms. Our method, does not trigger the perturbation by the displacement of COM initially and therefore, triggers fewer mechanisms for regaining balance.

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