Cylindrical Shell Control With Center- and Corner-Placed Photostrictive Skew-Quad Actuator Systems

2012 ◽  
Vol 134 (2) ◽  
Author(s):  
J. Jiang ◽  
H. H. Yue ◽  
Z. Q. Deng ◽  
H. S. Tzou
Keyword(s):  
Cylindrical Shell ◽  
High Energy ◽  
Negative Control ◽  
Control Effectiveness ◽  
Actuator System ◽  
Control Forces ◽  
And Control ◽  
Paired Design ◽  
Actuator Design ◽  
Photostrictive Actuators

Light-driven photostrictive actuators can induce control actions for wireless non-contact actuation and control of precision structures and systems. Conventional distributed actuators laminated on shells and plates usually only introduce uniform control forces and moments. Structural actuation and control based on uniform control forces and moments have been investigated for over two decades. This paper is to exploit a new photostrictive actuator design, i.e., a skew-quad (SQ) actuator system. This new distributed SQ actuator system laminated on shells and plates can introduce non-uniform control forces and moments. The new SQ actuator system is composed of four pieces of photostrictive materials and the inner two edges of each piece are bonded to a cross fixture. Under the irradiation of high-energy lights, each piece generates non-uniform control forces and moments, due to its uneven non-symmetrical boundary conditions. Modal actuation characteristics of a cylindrical shell coupled with the center-placed and corner-placed SQ actuator systems are evaluated respectively. A paired-design regulating positive/negative control forces of each actuator region is also proposed and evaluated to improve the control effectiveness of the center-located SQ actuator system. Parametric analysis proves improved control effectiveness of unsymmetrical shell modes.

Cylindrical Shell Control With Center- and Corner-Placed Photostrictive Skew-Quad Actuators

2010 ◽  
Author(s):  
Jing Jiang ◽  
Hong-Hao Yue ◽  
Zong-Quan Deng ◽  
Horn-Sen Tzou
Keyword(s):  
Cylindrical Shell ◽  
High Energy ◽  
Negative Control ◽  
Control Effectiveness ◽  
Actuator System ◽  
Control Forces ◽  
And Control ◽  
Paired Design ◽  
Actuator Design ◽  
Photostrictive Actuators

Light-driven photostrictive actuators can induce control actions capable of wireless non-contact actuation and control of precision structures and systems. Conventional distributed actuators laminated on shells and plates usually introduce only uniform control forces and moments. Structural actuation and control based on uniform control forces and moments have been investigated for over two decades. This paper is to exploit a new photostrictive actuator design, i.e., a skew-quad (SQ) actuator system and this new distributed SQ system laminated on shells and plates can introduce non-uniform control forces and moments. The new SQ actuator system is composed of four pieces of photostrictive materials and inner two edges of each piece are bonded to a cross fixture. Under the irradiation of high-energy lights, each piece generates non-uniform control forces and moments, due to its uneven nonsymmetrical boundary conditions. Modal actuation characteristics of a cylindrical shell coupled with a center-placed and corner-placed skew-quad actuator system are evaluated respectively. A paired-design regulating positive/negative control forces of each actuator region is proposed to improve the control effectiveness of the center-located skew-quad actuator system. Parametric analysis proves improved control effectiveness of unsymmetrical shell modes.

Light-Induced Non-Contact Actuation and Control With Photostrictive Actuators

1997 ◽  
Author(s):  
H. S. Tzou ◽  
B. J. Liu
Keyword(s):  
Constitutive Relations ◽  
Cylindrical Shells ◽  
Time History ◽  
Ultra Violet ◽  
High Energy ◽  
Electromechanical Actuators ◽  
Modeling And Analysis ◽  
Control Effectiveness ◽  
Control Forces ◽  
And Control

Abstract Non-contact light activated distributed opto-electromechanical actuators represent a new class of precision distributed actuator which are based on the photodeformation process and controlled by high energy lights, e.g., lasers and ultra-violet lights. Fundamental opto-thermo-electromechancial constitutive relations are discussed and formulations of optically induced control forces and moments introduced. Mathematical modeling and analysis of distributed opto-electromechanical shell actuators are presented. A generic distributed photo-actuation theory is proposed and the closed-loop opto-thermo-electromechancial equations of circular cylindrical shells are derived. The systems equations reveal the couplings among elasticity, photodeformation, pyroelectricity, and thermoelasticity. Active distributed control of flexible cylindrical shells using segmented distributed opto-electromechanical shell actuators are investigated and the control effectiveness is evaluated. Membrane and bending control effects are evaluated. Time history analyses of independent modal control reveal that the Lyapunov control is more effective than the proportional feedback control.

Non Contact Precision Actuation and Optimal Actuator Placement of Hybrid Photostrictive Beam Structronic Systems

2007 ◽  
Author(s):  
Hong-Hao Yue ◽  
Zong-Quan Deng ◽  
Horn-Sen Tzou
Keyword(s):  
Photovoltaic Effect ◽  
Mechanical Strain ◽  
Elastic Beam ◽  
High Energy ◽  
Design Parameters ◽  
Control Electronics ◽  
Control Forces ◽  
And Control ◽  
Converse Piezoelectric Effect ◽  
Photostrictive Actuators

Non-contact wireless actuation offers many advantages to precision control, as compared with conventional hard-wired actuation mechanisms. High-energy laser or ultraviolet lights irradiating on photostrictive materials can induce a photodeformation process involving two fundamental effects: 1) the photovoltaic effect and 2) the converse piezoelectric effect. This photodeformation process transforms photonic energy to mechanical strain/stress that can be directly used for actuation and control applications. With specific design configurations, the photodeformation process of photostrictive actuators can induce various control forces and moments applied to precision manipulation and control of mechatronic and structronic systems. In this study, fundamental photodeformation coupling mechanisms among photo-thermo-electromechanical/control fields are investigated and parametric evaluation of various design parameters of a hybrid photostrictive/elastic beam is conducted. A mathematical model for a laminated beam with segmented photostrictive actuators is defined, followed by photodeformation induced modal control forces and moments of segmented actuators. Characteristics of actuation and control effectiveness of distributed photostrictive actuators at various locations, natural modes and illumination intensities are analyzed in case studies. The most effective actuator location(s) for controlling the first four beam modes are illustrated. Finally, with scheduling light irradiations on various photostrictive actuators, one can control multiple beam modes, allowed by control electronics and material response.

Actuator Placement and Micro-Actuation Efficiency of Adaptive Paraboloidal Shells

2003 ◽  
Vol 125 (4) ◽  
pp. 577-584 ◽  
Author(s):  
H. S. Tzou ◽  
J. H. Ding
Keyword(s):  
Communication Systems ◽  
Design Parameters ◽  
Shells Of Revolution ◽  
Control Effect ◽  
Control Effectiveness ◽  
Membrane Bending ◽  
High Control ◽  
Control Forces ◽  
And Control ◽  
Actuator Placement

Paraboloidal shells of revolution are commonly used in communication systems, precision opto-mechanical systems and aerospace structures. This study is to investigate the precision distributed control effectiveness of adaptive paraboloidal shells laminated with segmented actuator patches. Mathematical models of the paraboloidal shells laminated with distributed actuator layers subjected to mechanical, temperature, and control forces are presented first. Then, formulations of distributed actuating forces with their contributing micro-meridional/circumferential membrane and bending components are derived using an assumed mode shape function. Studies of actuator placements, actuator induced control forces, micro-contributing components, and normalized actuation authorities of paraboloidal shells are carried out. These forces and membrane/bending components basically exhibit distinct modal characteristics influenced by shell geometries and other design parameters. Analyses suggest that the membrane-contributed components dominate the overall control effect. Locations with larger normalized forces indicate the areas with high control efficiencies, i.e., larger induced actuation force per unit actuator area. With limited actuators, placing actuators at those locations would lead to the maximal control effects of paraboloidal shells.

Non-Uniform Control Moments Induced by a Skew-Quad Actuator Design Applied to Plate Controls

2009 ◽  
Author(s):  
Jing Jiang ◽  
Hong-Hao Yue ◽  
Zong-Quan Deng ◽  
Horn-Sen Tzou
Keyword(s):  
Piezoelectric Materials ◽  
Flexible Structures ◽  
Variation Method ◽  
Modal Control ◽  
Control Effectiveness ◽  
Control Actions ◽  
Distributed Structures ◽  
Control Forces ◽  
Parametric Analyses ◽  
Actuator Design

Distributed vibration control of flexible structures using piezoelectric materials has been extensively studied for decades. A number of design configurations of distributed actuators with uniform control forces and moments have been investigated to improve modal control effectiveness of distributed structures, e.g., shells and plates. In this study, a new skew-quad actuator design which consists of four pieces of mono-axial piezoelectric actuator is proposed and evaluated. Due to the uneven boundary conditions of each region, this new actuator can induce non-uniform control forces and moments. Based on the variation method, the non-uniform distribution of the actuator induced forces and moments are defined. The coupling equation of a simply supported plate laminated with this new design is derived; distributed control action resulting from the non-uniform control moments is also defined in the modal domain. The actuator induced control actions are calculated respectively on a square plate and a rectangle plate, and the effects of varying actuator size are also evaluated. These control effects of the skew-quad actuator are compared with those of a multi-DOF actuator. Parametric analyses suggest that due to the non-uniform control moments, the new skew-quad actuator induces better modal control actions in certain plate modes as compared with the multi-DOF actuator. This new skew-quad actuator has great potential to improve control effects to other shell structures.

scholarly journals Dynamics and Control of Adaptive Shells with Curvature Transformations

1995 ◽  
Vol 2 (2) ◽  
pp. 143-154 ◽  
Author(s):  
H.S. Tzou ◽  
Y. Bao
Keyword(s):  
Cylindrical Shell ◽  
Shallow Shell ◽  
Natural Frequencies ◽  
Velocity Feedback ◽  
Control Effectiveness ◽  
Dynamics And Control ◽  
Continuous Curvature ◽  
And Control ◽  
Variable Focus ◽  
Shell Composite

Adaptive structures with controllable geometries and shapes are rather useful in many engineering applications, such as adaptive wings, variable focus mirrors, adaptive machines, micro-electromechanical systems, etc. Dynamics and feedback control effectiveness of adaptive shells whose curvatures are actively controlled and continuously changed are evaluated. An adaptive piezoelectric laminated cylindrical shell composite with continuous curvature changes is studied, and its natural frequencies and controlled damping ratios are evaluated. The curvature change of the adaptive shell starts from an open shallow shell (30°) and ends with a deep cylindrical shell (360°). Dynamic characteristics and control effectiveness (via the proportional velocity feedback) of this series of shells are investigated and compared at every 30° curvature change. Analytical solutions suggest that the lower modes are sensitive to curvature changes and the higher modes are relatively insensitive.

scholarly journals Current Knowledge and Future Directions for Improving Subsoiling Quality and Reducing Energy Consumption in Conservation Fields

Agriculture ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 575
Author(s):  
Shangyi Lou ◽  
Jin He ◽  
Hongwen Li ◽  
Qingjie Wang ◽  
Caiyun Lu ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Cover Crops ◽  
Current Knowledge ◽  
High Energy ◽  
Field Application ◽  
Research Progress ◽  
Monitoring And Control ◽  
Future Directions ◽  
Tillage Depth ◽  
And Control

Subsoiling has been acknowledged worldwide to break compacted hardpan, improve soil permeability and water storage capacity, and promote topsoil deepening and root growth. However, there exist certain factors which limit the wide in-field application of subsoiling machines. Of these factors, the main two are poor subsoiling quality and high energy consumption, especially the undesired tillage depth obtained in the field with cover crops. Based on the analysis of global adoption and benefits of subsoiling technology, and application status of subsoiling machines, this article reviewed the research methods, technical characteristics, and developing trends in five key aspects, including subsoiling shovel design, anti-drag technologies, technologies of tillage depth detection and control, and research on soil mechanical interaction. Combined with the research progress and application requirements of subsoiling machines across the globe, current problems and technical difficulties were analyzed and summarized. Aiming to solve these problems, improve subsoiling quality, and reduce energy consumption, this article proposed future directions for the development of subsoiling machines, including optimizing the soil model in computer simulation, strengthening research on the subsoiling mechanism and comprehensive effect, developing new tillage depth monitoring and control systems, and improving wear-resisting properties of subsoiling shovels.

scholarly journals Closed-form time derivatives of the equations of motion of rigid body systems

2021 ◽  
Author(s):  
Andreas Müller ◽  
Shivesh Kumar
Keyword(s):  
Rigid Body ◽  
Closed Form ◽  
Multibody Systems ◽  
Equations Of Motion ◽  
Alternative Formulation ◽  
Dynamics Of Rigid Body ◽  
Control Forces ◽  
And Control ◽  
Derivatives Of ◽  
Insight Into

AbstractDerivatives of equations of motion (EOM) describing the dynamics of rigid body systems are becoming increasingly relevant for the robotics community and find many applications in design and control of robotic systems. Controlling robots, and multibody systems comprising elastic components in particular, not only requires smooth trajectories but also the time derivatives of the control forces/torques, hence of the EOM. This paper presents the time derivatives of the EOM in closed form up to second-order as an alternative formulation to the existing recursive algorithms for this purpose, which provides a direct insight into the structure of the derivatives. The Lie group formulation for rigid body systems is used giving rise to very compact and easily parameterized equations.

scholarly journals Overfeeding Extends the Period of Annual Cyclicity but Increases the Risk of Early Embryonic Death in Shetland Pony Mares

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 361
Author(s):  
Nicky M. M. D’Fonseca ◽  
Charlotte M. E. Gibson ◽  
Iris Hummel ◽  
David A. van Doorn ◽  
Ellen Roelfsema ◽  
...  
Keyword(s):  
Embryo Transfer ◽  
Reproductive Activity ◽  
High Energy ◽  
Morphometric Parameters ◽  
Net Energy ◽  
Conceptus Development ◽  
And Control ◽  
Annual Duration ◽  
Embryonic Death

Obesity has been associated with altered reproductive activity in mares, and may negatively affect fertility. To examine the influence of long-term high-energy (HE) feeding on fertility, Shetland pony mares were fed a diet containing 200% of net energy (NE) requirements during a three-year study. The incidence of hemorrhagic anovulatory follicles (HAF) and annual duration of cyclicity were compared to those in control mares receiving a maintenance diet. Day-7 embryos were flushed and transferred between donor and recipient mares from both groups; the resulting conceptuses were collected 21 days after transfer to assess conceptus development. HE mares became obese, and embryos recovered from HE mares were more likely to succumb to early embryonic death. The period of annual cyclicity was extended in HE compared to control mares in all years. The incidence of HAFs did not consistently differ between HE and control mares. No differences in embryo morphometric parameters were apparent. In conclusion, consuming a HE diet extended the duration of cyclicity, and appeared to increase the likelihood of embryos undergoing early embryonic death following embryo transfer.

Reduced substrate oxidation in postischemic myocardium: 13C and 31P NMR analyses

1990 ◽  
Vol 258 (5) ◽  
pp. H1357-H1365 ◽  
Author(s):  
E. D. Lewandowski ◽  
D. L. Johnston
Keyword(s):  
Steady State ◽  
31P Nmr ◽  
Tca Cycle ◽  
High Energy ◽  
Substrate Oxidation ◽  
High Energy Phosphates ◽  
Atp Content ◽  
And Control ◽  
13C And 31P Nmr ◽  
Postischemic Myocardium

13C and 31P nuclear magnetic resonance (NMR) spectra were used to assess substrate oxidation and high-energy phosphates in postischemic (PI) isolated rabbit hearts. Phosphocreatine (PCr) increased in nonischemic controls on switching from glucose perfusion to either 2.5 mM [3-13C]pyruvate (120%, n = 7) or [2-13C]acetate (114%, n = 8, P less than 0.05). ATP content, oxygen consumption (MVO2), and hemodynamics (dP/dt) were not affected by substrate availability in control or PI hearts. dP/dt was 40-60% lower in PI hearts during reperfusion after 10 min ischemia. Hearts reperfused with either pyruvate (n = 11) or acetate (n = 8) regained preischemic PCr levels within 45 s. Steady-state ATP levels were 55-70% of preischemia with pyruvate and 52-60% with acetate. Percent maximum [4-13C]glutamate signal showed reduced conversion of pyruvate to glutamate via the tricarboxylic acid (TCA) cycle at 4-min reperfusion (PI = 24 +/- 4%, means +/- SE; Control = 48 +/- 4%). The increase in 13C signal from the C-4 position of glutamate was similar to control hearts within 10.5 min. The increase in [4-13C]glutamate signal from acetate was not different between PI and control hearts. The ratio of [2-13C]Glu:[4-13C]Glu, reflecting TCA cycle activity, was reduced in PI hearts with acetate for at least 10 min (Control = 0.76 +/- 0.03; PI = 0.51 +/- 0.09) until steady state was reached. Despite rapid recovery of oxidative phosphorylation, contractility remained impaired and substrate oxidation was significantly slowed in postischemic hearts.

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