Dynamic Behavior of Piezoelectric Recurve Actuation Architectures

2004 ◽  
Vol 126 (1) ◽  
pp. 37-46 ◽  
Author(s):  
James D. Ervin ◽  
Diann E. Brei
Keyword(s):  
Dynamic Behavior ◽  
Architectural Design ◽  
Dynamic Models ◽  
Dynamic Performance ◽  
Design Parameters ◽  
New Family ◽  
State Frequency ◽  
Actuation Scheme ◽  
The Impact ◽  
High Work

A new family of piezoelectric actuators, called Recurves, exhibits high work per volume and have the extra benefit of performance and packaging tailorability. The focus of this paper is the dynamic performance of this novel actuation scheme. Two dynamic models, a detailed transfer matrix model and a simpler rod approximation model, are presented to predict the steady state frequency response of a general Recurve actuator driving a mass and spring load. Results from a 23 design of experiments are given that validate these models and demonstrate the impact of the architectural design parameters on the dynamic behavior of a generic Recurve actuator.

Modeling and Experimental Characterization of the Dynamic Behavior of Piezoelectric Recurve Actuation Architectures

1999 ◽  
Author(s):  
James D. Ervin ◽  
Diann E. Brei
Keyword(s):  
Dynamic Behavior ◽  
Architectural Design ◽  
Dynamic Models ◽  
Dynamic Performance ◽  
Design Parameters ◽  
New Family ◽  
State Frequency ◽  
Actuation Scheme ◽  
The Impact

Abstract There are numerous applications that require fast actuators to deliver specific force and displacement output while fitting into confined spaces. A new family of piezoelectric actuators called Recurves exhibit high work per volume and have the extra benefit of having both the force-deflection performance and packaging tailorable to fit the requirements of a given application. The focus of this paper is the dynamic performance of this novel actuation scheme. Two dynamic models, a detailed transfer matrix model and a simpler rod approximation model, are presented to predict the steady state frequency response of a general Recurve actuator driving a mass and spring load. Results from a 23 design of experiments are given that validate these models and demonstrate the impact of the architectural design parameters on the dynamic behavior of the general Recurve actuator.

Discrete modular serpentine robotic tail: design, analysis and experimentation

Robotica ◽  
2018 ◽  
Vol 36 (7) ◽  
pp. 994-1018 ◽  
Author(s):  
Wael Saab ◽  
William S. Rone ◽  
Pinhas Ben-Tzvi
Keyword(s):  
Dynamic Models ◽  
Design Analysis ◽  
Degree Of Freedom ◽  
Legged Robots ◽  
Design Parameters ◽  
Inertial Loading ◽  
Forward Kinematic ◽  
The Impact ◽  
Accuracy And Repeatability ◽  
Two Degree Of Freedom

SUMMARYThis paper presents the design, analysis and experimentation of a Discrete Modular Serpentine Tail (DMST). The mechanism is envisioned for use as a robotic tail integrated onto mobile legged robots to provide a means, separate from the legs, to aid stabilization and maneuvering for both static and dynamic applications. The DMST is a modular two-degree-of-freedom (DOF) articulated, under-actuated mechanism, inspired by continuum and serpentine robotic structures. It is constructed from rigid links with cylindrical contoured grooves that act as pulleys to route and maintain equal displacements in antagonistic cable pairs that are connected to a multi-diameter pulley. Spatial tail curvatures are produced by adding a roll-DOF to rotate the bending plane of the planar tail curvatures. Kinematic and dynamic models of the cable-driven mechanism are developed to analyze the impact of trajectory and design parameters on the loading profiles transferred through the tail base. Experiments using a prototype are performed to validate the forward kinematic and dynamic models, determine the mechanism's accuracy and repeatability, and measure the mechanism's ability to generate inertial loading.

scholarly journals Design and Optimization of a Dual-Input Coupling Powertrain System: A Case Study for Electric Tractors

2020 ◽  
Vol 10 (5) ◽  
pp. 1608
Author(s):  
Tonghui Li ◽  
Bin Xie ◽  
Zhen Li ◽  
Jiakun Li
Keyword(s):  
Dynamic Models ◽  
Optimal Parameter ◽  
Dynamic Performance ◽  
Energy Utilization ◽  
Utilization Efficiency ◽  
Design Parameters ◽  
Feasible Region ◽  
Energy Management Strategy ◽  
Powertrain System ◽  
Overall Efficiency

In this study, a dual-input coupling powertrain system (DICPS) was proposed to improve the energy utilization efficiency of pure electric tractors (PETs). The working principles of the DICPS under different modes were analyzed and dynamic models were established. To study the influence of changing key parameters in the DICPS on the economic performance of PETs, a parameter-matching design method was proposed and the feasible region of the design parameters was determined according to the tractor’s dynamic performance. In addition, we put forward an energy management strategy (EMS) based on the optimal system efficiency and a dual-motor-driven electric tractor (DMET) model was built in MATLAB/Simulink. The simulation results revealed that different parameter configurations of DICPS will lead to significant changes in overall efficiency, with a maximum difference of 6.6% (under a rotary tillage cycle). We found that the optimal parameter configuration for the DMET under two typical working conditions was PDR = 0.5, k = 1.6. Compared with the single-motor powertrain system (SMPS), the DICPS with the optimal configuration of key parameters can significantly improve overall efficiency by about 9.8% (under a plowing cycle).

THE IMPACT OF THE DIMENSION OF A MATHEMATICAL MODEL OF INTERNAL BALLISTICS ON DESIGN PARAMETERS OF A SHOT FOR GRAIN GUNPOWDER CHARGES

2021 ◽  
pp. 95-110
Author(s):  
I.G. Rusyak ◽  
◽  
V.A. Tenenev ◽  
Keyword(s):  
Mathematical Model ◽  
Powder Mixture ◽  
Thermodynamic Model ◽  
Dynamic Models ◽  
Design Parameters ◽  
Variable Cross ◽  
One Dimensional ◽  
Gas Dynamic ◽  
Wide Range ◽  
The Impact

The problem of the impact of the mathematical model dimension on the calculated intraballistic characteristics of a shot for the charges made of granulated powder is considered. Mathematical models of the shot are studied using the spatial (axisymmetric), one-dimensional, and zero-dimensional (thermodynamic) formulations. The thermodynamic model takes into account the distribution of the pressure and velocity of a gas-powder mixture behind the shot for a channel of variable cross-section. Comparison of simulation results is carried out in a wide range of loading parameters. It is shown that there is a range of the loading parameters for a thermodynamic approach to give satisfactory approximation to the parameters obtained using the gas-dynamic approach, which describes the flow of a heterogeneous reacting mixture with a separate consideration of phases and intergranular interactions between them. Notably that in the entire range of the charging parameters studied in this work, the one-dimensional and twodimensional gas-dynamic models only slightly differ from each other. Therefore, in the main pyrodynamic period, the actuation of the charge, made of granulated powder, can be simulated using a one-dimensional gas-dynamic model or a zero-dimensional thermodynamic model with allowance for spatial distribution of the pressure and velocity of the gas-powder mixture.

Bearings Influence on the Dynamic Behavior of HSM Spindle

2012 ◽  
Author(s):  
David Noel ◽  
Mathieu Ritou ◽  
Sebastien Le Loch ◽  
Benoit Furet
Keyword(s):  
Dynamic Behavior ◽  
High Speed ◽  
Degrees Of Freedom ◽  
Experimental Tests ◽  
Operating Conditions ◽  
Design Parameters ◽  
Mechanics Model ◽  
Bearing Stiffness ◽  
Rough Milling ◽  
The Impact

The aeronautic industry requires high speed and high power spindles to obtain high material removal rates during long rough milling operations. The weakness of HSM spindle is the bearings, although high precision hybrid ball bearings have been developed to achieve this critical application. Inadequate use of spindles inevitably leads to shortened lifetimes. Choosing the operating conditions is a required step before machining applications. It can be achieved through either experimental tests or numerical modeling that leads to stability lobe diagrams. Stability of cuts relies on the dynamic behavior of the spindle, which is particularly due to the eigenfrequencies of the tool-shaft assembly. The frequencies depend on bearing stiffness that can change under operating conditions. That is why the impact of cutting conditions and bearing parameters on its stiffness are studied in the paper. A five degrees of freedom model of angular ball bearing is briefly presented. A complete bearing model is introduced. The originality of the approach is the complete technological modeling, notably of the radial expansions of inner and outer rings of bearing. A non-linear expression is established from continuum mechanics model. The influence of geometry of bearing, operating conditions and design parameters of spindle on the bearing stiffness are established and analysed. Then, modal analyses of the tool-spindle assembly are carried out in relation to the varying bearing stiffness. Finally, significance of the approach is demonstrated through the analyses of Frequency Response Function.

Advantages of surrogate models for architectural design optimization

2015 ◽  
Vol 29 (4) ◽  
pp. 471-481 ◽  
Author(s):  
Thomas Wortmann ◽  
Alberto Costa ◽  
Giacomo Nannicini ◽  
Thomas Schroepfer
Keyword(s):  
Genetic Algorithms ◽  
Design Problem ◽  
Architectural Design ◽  
Optimization Problems ◽  
Resource Depletion ◽  
Surrogate Models ◽  
Performance Criteria ◽  
Design Parameters ◽  
Metaheuristic Methods ◽  
The Impact

AbstractClimate change, resource depletion, and worldwide urbanization feed the demand for more energy and resource-efficient buildings. Increasingly, architectural designers and consultants analyze building designs with easy-to-use simulation tools. To identify design alternatives with good performance, designers often turn to optimization methods. Randomized, metaheuristic methods such as genetic algorithms are popular in the architectural design field. However, are metaheuristics the best approach for architectural design problems that often are complex and ill defined? Metaheuristics may find solutions for well-defined problems, but they do not contribute to a better understanding of a complex design problem. This paper proposes surrogate-based optimization as a method that promotes understanding of the design problem. The surrogate method interpolates a mathematical model from data that relate design parameters to performance criteria. Designers can interact with this model to explore the approximate impact of changing design variables. We apply the radial basis function method, a specific type of surrogate model, to two architectural daylight optimization problems. These case studies, along with results from computational experiments, serve to discuss several advantages of surrogate models. First, surrogate models not only propose good solutions but also allow designers to address issues outside of the formulation of the optimization problem. Instead of accepting a solution presented by the optimization process, designers can improve their understanding of the design problem by interacting with the model. Second, a related advantage is that designers can quickly construct surrogate models from existing simulation results and other knowledge they might possess about the design problem. Designers can thus explore the impact of different evaluation criteria by constructing several models from the same set of data. They also can create models from approximate data and later refine them with more precise simulations. Third, surrogate-based methods typically find global optima orders of magnitude faster than genetic algorithms, especially when the evaluation of design variants requires time-intensive simulations.

A Spring-Actuated, Cam-Follower System: Design Theory and Experimental Results

1965 ◽  
Vol 87 (3) ◽  
pp. 279-286 ◽  
Author(s):  
P. Barkan ◽  
R. V. McGarrity
Keyword(s):  
System Design ◽  
Dynamic Behavior ◽  
Design Theory ◽  
Dynamic Performance ◽  
Simplified Model ◽  
Design Synthesis ◽  
Cam Follower ◽  
Graphical Technique ◽  
Improved Technique ◽  
The Impact

An improved technique for the design synthesis of a spring-actuated, cam-follower system is described. Long-hand calculations and a simple graphical technique suffice to design a system to meet prescribed dynamic performance characteristics. By analysis of a simplified model, the response of the system to the impact accompanying take-up of clearance is related to four dimensionless parameters. A comparison of theory and tests on one design substantiate the utility of the synthesis technique and also provide additional insights into the dynamic behavior of such systems.

scholarly journals Efficient Envelope Designs to Maximize Residential Cooling Energy Savings in Bangkok Neighborhoods

2021 ◽  
Vol 20 ◽  
pp. 103
Author(s):  
Natthaumporn Inprom ◽  
Daranee Jareemit
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Architectural Design ◽  
Energy Savings ◽  
Gain Coefficient ◽  
Design Parameters ◽  
Design Guideline ◽  
New Energy ◽  
Building Energy Analysis ◽  
The Impact

Architectural design can significantly improve home energy-efficiency. New energy-saving techniques are regularly proposed; however, integrating all design parameters into the energy simulation specific knowledge and is time-consuming, making it difficult for non-experts in building energy analysis. This present study investigates the impact of envelope designs on household cooling energy consumption in housing complexes located in Bangkok neighborhood areas. The study selects a representative house and identifies a range of envelope designs, including thermal properties of exterior walls and roof, painted color, length of roof eaves, and window-to-wall ratio (WWR). The Latin hypercube method randomly generates two hundred sets of design scenarios based on those design parameters. The eQuest model is used to perform analysis of household cooling energy consumption for four orientations, and the simulation results are validated. The standardized regression coefficient (SRC) is used to determine a strong correlation between design parameters and cooling energy consumption in detached houses. The results reveal that improving a window’s solar heat gain coefficient (SHGC), wall painted color, wall u-value, and length of roof eaves could reduce energy consumption by up to 19.7 percent. The WWR and building orientation were found to have only a small impact on household cooling energy consumption, especially for a square-shaped house. The results provide designers and non-professional a simple design guideline to improve the energy efficiency of their home designs.

Monetary policy and the effect of the transfer of oil prices to inflation

2020 ◽  
pp. 41-50
Author(s):  
Ph. S. Kartaev ◽  
I. D. Medvedev
Keyword(s):  
Monetary Policy ◽  
Inflation Targeting ◽  
Dynamic Models ◽  
Oil Prices ◽  
Oil Price ◽  
Oil Price Shocks ◽  
Negative Effects ◽  
Price Shocks ◽  
Policy Regime ◽  
The Impact

The paper examines the impact of oil price shocks on inflation, as well as the impact of the choice of the monetary policy regime on the strength of this influence. We used dynamic models on panel data for the countries of the world for the period from 2000 to 2017. It is shown that mainly the impact of changes in oil prices on inflation is carried out through the channel of exchange rate. The paper demonstrates the influence of the transition to inflation targeting on the nature of the relationship between oil price shocks and inflation. This effect is asymmetrical: during periods of rising oil prices, inflation targeting reduces the effect of the transfer of oil prices, limiting negative effects of shock. During periods of decline in oil prices, this monetary policy regime, in contrast, contributes to a stronger transfer, helping to reduce inflation.

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