Planar Motion Control, Coordination and Dynamic Entrainment in Chaplygin Beanies

2018 ◽  
Author(s):  
Scott Kelly ◽  
Rodrigo Abrajan-Guerrero ◽  
Jaskaran Grover ◽  
Matthew Travers ◽  
Howie Choset
Keyword(s):  
Energy Transfer ◽  
Motion Control ◽  
Nonholonomic Constraint ◽  
The Other ◽  
Planar Motion ◽  
Single Input ◽  
Robotic Vehicle

The Chaplygin beanie is a single-input robotic vehicle for which partial planar motion control can be achieved by exploiting a simple nonholonomic constraint. A previous paper suggested a strategy for such motion control. In the present paper, this strategy is validated experimentally and extended to the context of multi-vehicle coordination. It is then shown that when the plane on which two such vehicles operate is translationally compliant, energy transfer between the two can enable a mechanism whereby one (operating under control) may entrain the other (operating passively), partly coordinating their motion. As an extension to this result, it is further demonstrated that a pair of passive vehicles operating on a translationally compliant platform can eventually attain the same heading when released from their deformed configurations.

Comparative Spectroscopic Studies on Luminescence Performance of Er3+ Doped Tellurite Glass Embedded with Different Nanoparticles (Ag Co and Fe) at 0.55 μm Emission

2021 ◽  
Vol 317 ◽  
pp. 81-86
Author(s):  
Syariffah Nurathirah Syed Yaacob ◽  
Md. Rahim Sahar ◽  
Faizani Mohd Noor ◽  
Nur Liyana Amiar Rodin ◽  
Siti Khadijah Mohd Zain ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Ground State ◽  
Tellurite Glass ◽  
Spectroscopic Studies ◽  
The Other ◽  
X Ray Diffraction ◽  
Melt Quenching ◽  
X Ray ◽  
Doped Glass ◽  
Luminescence Performance

The spectroscopic performance of Er3+ doped glass at 0.55 mm emission contain different nanoparticles NPs have been comparatively evaluated. Glass containing 1.0 mol % of Er3+ doped with different NPs (Ag, Co and Fe ) have been prepared using melt quenching technique. X-ray diffraction analysis reveals the all the prepared samples are amorphous. The UV-Vis absorption spectra of all glasses show several prominent peaks at 525 nm, 660 nm, 801nm, 982 nm and 959 nm due to transition from ground state 4I15/2 to different excited of 2H11/2, 4F9/2, 4I9/2, 4I11/2, and 4I13/2. The emission of Er3+ at 0.55 mm for glass contain Ag NP shows significant enhancement about 3 folds up to 0.6 mol%. On the other hand, the emission of Er3+ at 0.55 mm for glass containing Fe NPs and Co NPs intensely quench probably due to the energy-transfer from Er3+ ion to NPs and magnetic contributions.

scholarly journals FORCED CONVECTION IN DUCTS WITH PERMEABLE WALLS

2003 ◽  
Vol 2 (1) ◽  
pp. 58
Author(s):  
C. H. Alexandrino ◽  
M. L. Martins-Costa
Keyword(s):  
Energy Transfer ◽  
Finite Difference ◽  
Mixture Theory ◽  
Theory Model ◽  
The Other ◽  
Convective Term ◽  
Compatibility Conditions ◽  
Fluid Mixture ◽  
Local Description ◽  
Permeable Walls

A mixture theory model is employed in a local description of the energy transfer in a duct with permeable wall which is simulated by considering two distinct flow regions, one consisting of a Newtonian incompressible fluid and the other represented by a binary (solid-fluid) mixture. Compatibility conditions at the interface (pure fluid-mixture) for momentum and energy transfer are considered. The simulations are carried out by using a finite difference approach with an upwind strategy for the convective term discretization.

A new type of triphenylamine based coumarin–rhodamine hybrid compound: synthesis, photophysical properties, viscosity sensitivity and energy transfer

RSC Advances ◽  
2016 ◽  
Vol 6 (107) ◽  
pp. 105387-105397 ◽  
Author(s):  
Shantaram Kothavale ◽  
Nagaiyan Sekar
Keyword(s):  
Energy Transfer ◽  
Phenyl Ring ◽  
Photophysical Properties ◽  
The Other ◽  
Hybrid Compound ◽  
Compound Synthesis ◽  
New Type ◽  
Molecular Skeleton

A series of novel core modified triphenylamine coumarin–rhodamine systems (compounds MCMR, MCDR and DCMR) was designed and synthesized by incorporating a coumarin moiety on one and a rhodamine moiety on the other phenyl ring of the triphenylamine molecular skeleton.

2-DOF Planar Motion Control System Using Model Reference Adaptive Control (MRAC) Algorithm

2012 ◽  
Author(s):  
Andrew M. Y. Luk ◽  
Eric H. K. Fung ◽  
W. C. Gan
Keyword(s):  
Adaptive Control ◽  
Control System ◽  
Motion Control ◽  
Pid Controller ◽  
Model Reference Adaptive Control ◽  
Planar Motion ◽  
Motion Platform ◽  
Motion Control System ◽  
Model Reference ◽  
Model Reference Adaptive

This paper reports the application of Model Reference Adaptive Control (MRAC) to an X-Y planar motion mechanism. A flexure-based 2-DOF planar motion platform is first developed for the wafer probing purpose and a planar Voice Coil Motor (VCM) is used for driving the mechanism and the flexural bearings. The dynamics of the motion platform is governed by a set of differential equations using the mass-spring-damper model and the Kirchhoff’s circuit laws. Due to the non-linearity of the force constant and the coupling effect of the VCM, a MRAC algorithm is proposed to implement on the motion control system so as to improve the system transient response. In order to guarantee the stability of the Model Reference Adaptive System (MRAS), Lyapunov Theory is adopted in the controller design. The control system performance is simulated using MATLAB /SIMULINK with the considerations of the motor non-linearity and the assembly variation of the flexural mechanism. On the other hand, a conventional PID controller is also constructed for control experiments to compare the transient responses between MRAC and PID control systems. Simulation results revealed that the proposed MRAS outperforms the PID controller for the 2 DOF planar motion system in the presence of sensor noise, disturbing force and parameter variation effects.

Ship Motion Control System for Replenishment Operation

2016 ◽  
Vol 817 ◽  
pp. 214-222
Author(s):  
Witold Gierusz ◽  
Anna Miller
Keyword(s):  
Control System ◽  
Motion Control ◽  
Main Part ◽  
Ship Motion ◽  
The Other ◽  
Reference Trajectory ◽  
Model Predictive Controller ◽  
Motion Control System ◽  
Parallel Motion ◽  
Predictive Controller

Underway Replenishment is a procedure whose importance is rising in shipping. It is applied both to the naval and civil vessels. That is the reason why research in this area was undertaken. In this paper idea of the ship motion control system for replenishment operations was presented. The outline of the system is described in a detail way. This system incorporates Model Predictive Controller as a main part of the proposed algorithm. The other important part of the control system is a reference trajectory for the approaching ship generation. Conducted computer simulations prove that there is a possibility to synthesize MPC controller to maintain the pair of ships parallel motion during the UNREP operation.

Vibrational relaxation in gases

1959 ◽  
Vol 253 (1273) ◽  
pp. 277-288 ◽  
Keyword(s):  
Energy Transfer ◽  
Relaxation Process ◽  
Vibrational Relaxation ◽  
Vibrational Energy ◽  
Ultrasonic Waves ◽  
The Other ◽  
Ultrasonic Frequency ◽  
Hydrogen Atoms ◽  
Torsional Mode ◽  
Fundamental Frequencies

The velocity of ultrasonic waves has been measured in a number of gases at 25°C and for values of the ratio, ultrasonic frequency/pressure, ranging from 2 x 10 5 to 2 x 10 7 c s -1 atm -1 . Dispersion, corresponding to a single vibrational relaxation process was shown by acetylene, CD 3 Br and hexafluoro-ethane; and, to a double relaxation process, by ethane. Incipient dispersion was shown by propane, ethyl chloride, ethyl fluoride and dimethyl ether. No dispersion was shown by 1.1-difluoro-ethane, n -butane, iso -butane, neo -pentane and ammonia. Correlation of these with previous results leads to the conclusion that: ( а ) For molecules with a distribution of fundamental frequencies, such that there is only a small gap between the lowest and the remaining frequencies, vibrational activation enters via the lowest mode and spreads rapidly to the other modes, giving rise to a single relaxation process involving the whole of the vibrational energy. The chief factors determining the probability of excitation of the lowest mode are its frequency and the presence or absence of hydrogen atoms in the molecule. Molecules containing two or more hydrogen atoms suffer translational-vibrational energy transfer very much more easily than other molecules. Deuterium has almost the same effect as hydrogen. ( b ) For molecules, in which there is a large gap between the lowest and the remaining fundamental frequencies, a double relaxation process occurs. The complex energy transfer probabilities involved do not fit the same quantitative functional relation with vibrational frequency as in ( a ) above. ( c ) Torsional oscillations due to hindered internal rotation behave similarly to other fundamental modes. For molecules in which there is a large gap between the torsional frequency and the other modes (e. g. ethane) a double relaxation process occurs as in ( b ). Where there is no such gap, vibrational energy enters all modes via the torsional mode as in ( a ).

Sign in / Sign up

Export Citation Format

Share Document