Adaptive nonlinear design plant uncertainty cancellation for a multirotor

2016 ◽  
Author(s):  
Venkata S. Akkinapalli ◽  
Philipp Niermeyer ◽  
Boris Lohmann ◽  
Florian Holzapfel
Keyword(s):  
Nonlinear Design ◽  
Plant Uncertainty

scholarly journals The Transformative Potential of Ruins: A Tool for a Nonlinear Design Perspective in Adaptive Reuse

2021 ◽  
Vol 13 (10) ◽  
pp. 5660
Author(s):  
Elena Guidetti ◽  
Matteo Robiglio
Keyword(s):  
Adaptive Design ◽  
Future Research ◽  
Existing Buildings ◽  
Quantitative And Qualitative Research ◽  
Transformative Potential ◽  
Nonlinear Design ◽  
Mental Construct ◽  
Design Perspective ◽  
Novel Concept ◽  
The Relationship

In recent years, the heritage preservation debate has seen a growing interest in emerging theories in which the concept of potential plays an essential role. Starting from the assumption that memory is an evolving mental construct, the present paper introduces the concept of “transformative potential” in existing buildings. This novel concept regards the inevitability of loss and the self-destructive potential as part of the transformation of each building. The “transformative potential” is defined here as the relationship between spatial settings and material consistency. This research hypothesizes five “transformative potential” types by analyzing five best-practices adapted ruins in the last 15 years. The analysis integrates quantitative and qualitative research methods: morphological analysis (dimensional variations, critical redrawing, configuration patterns) and decay stages evaluation (shearing layers analysis, adaptation approaches). The goal is to test the “transformative potential” effectiveness in outlining patterns between specific stages of decay and adaptive design projects. Adaptation projects may actualize this potential in a specific time through incremental and decremental phases, outlining a nonlinear relationship between decay and memory. The study provides insights for future research on adapting existing buildings in a particular decay stage.

Topology Synthesis of Compliant Mechanisms for Nonlinear Force-Deflection and Curved Path Specifications

1999 ◽  
Vol 123 (1) ◽  
pp. 33-42 ◽  
Author(s):  
A. Saxena ◽  
G. K. Ananthasuresh
Keyword(s):  
Finite Element ◽  
Linear Models ◽  
Compliant Mechanisms ◽  
Synthesis Method ◽  
Design Sensitivity ◽  
Finite Element Models ◽  
Geometrically Nonlinear ◽  
Linear Elastic ◽  
Nonlinear Design ◽  
Nonlinear Force

Optimal design methods that use continuum mechanics models are capable of generating suitable topology, shape, and dimensions of compliant mechanisms for desired specifications. Synthesis procedures that use linear elastic finite element models are not quantitatively accurate for large displacement situations. Also, design specifications involving nonlinear force-deflection characteristics and generation of a curved path for the output port cannot be realized with linear models. In this paper, the synthesis of compliant mechanisms is performed using geometrically nonlinear finite element models that appropriately account for large displacements. Frame elements are chosen because of ease of implementation of the general approach and their ability to capture bending deformations. A method for nonlinear design sensitivity analysis is described. Examples are included to illustrate the usefulness of the synthesis method.

scholarly journals Frequency-Domain Robust Performance Condition for Controller Uncertainty in SISO LTI Systems: A Geometric Approach

2009 ◽  
Vol 2009 ◽  
pp. 1-9
Author(s):  
Vahid Raissi Dehkordi ◽  
Benoit Boulet
Keyword(s):  
Frequency Domain ◽  
Linear Time ◽  
Order Reduction ◽  
Geometric Approach ◽  
Geometrical Approach ◽  
Robust Performance ◽  
Linear Time Invariant ◽  
Additive Perturbation ◽  
Plant Uncertainty ◽  
Invariant Control

This paper deals with the robust performance problem of a linear time-invariant control system in the presence of robust controller uncertainty. Assuming that plant uncertainty is modeled as an additive perturbation, a geometrical approach is followed in order to find a necessary and sufficient condition for robust performance in the form of a bound on the magnitude of controller uncertainty. This frequency domain bound is derived by converting the problem into an optimization problem, whose solution is shown to be more time-efficient than a conventional structured singular value calculation. The bound on controller uncertainty can be used in controller order reduction and implementation problems.

Infeasibility and Non-Optimality Tests for Solution Space Reduction in Discrete Optimal Design

1992 ◽  
Author(s):  
Leonard P. Pomrehn ◽  
Panos Y. Papalambros
Keyword(s):  
Mathematical Model ◽  
Solution Space ◽  
Global Optimum ◽  
Gear Train ◽  
Discrete Variables ◽  
Multistage Process ◽  
Model Formulation ◽  
Space Reduction ◽  
Nonlinear Design ◽  
The Mathematical Model

Abstract Techniques to be employed for nonlinear design optimization with discrete variables are studied in the context of a particular problem arising from the design of a gear train. The mathematical model formulation was presented in an earlier article. In this sequel, a solution derivation is described, patterned as a multistage process. After certain reformulation and relaxation, a variety of infeasibility and non-optimality tests are performed, greatly reducing the size of the space containing the global optimum. Methods used to investigate the remaining space do not guarantee a global optimum, but could be replaced by more costly methods that do provide such guarantees. A global infimum is generated, bounding any improvements on the best known solution.

Nonlinear Design Model for Multi-Threshold Accelerometer Utilizing Magnetic Induced Multistable Mechanisms

2018 ◽  
Author(s):  
Jian Zhao ◽  
Yu Huang ◽  
Pengbo Liu ◽  
Qifei Fang ◽  
Renjing Gao
Keyword(s):  
Inertial Sensors ◽  
Coupling Effect ◽  
Design Method ◽  
Threshold Value ◽  
Consumer Electronics ◽  
Design Model ◽  
Acceleration Pulse ◽  
Locking Mechanism ◽  
Nonlinear Design ◽  
Controlling Elements

Different from traditional accelerometer, multi-threshold acceleration switch can be triggered to different working states by external accelerations without complex auxiliary circuits and controlling elements, which has great application potentials in aerospace, vehicle safety and consumer electronics. In this paper, a novel multi-threshold acceleration switch with anti-overloading function is designed and fabricated by incorporating both magnetic multi-stable structures and compliant cantilever contacts, which also can be used to distinguish specific acceleration pulse. To enhance the contact reliability, the magnetic compliant locking mechanism is introduced to prevent bouncing back phenomenon under overload acceleration. Considering the air-damping and multi-magnetic fields coupling effect, the dynamic design model is proposed for analyzing the nonlinear switch response. Then, threshold accelerations can be determined as ac1 = 3.78g, ac2 = 10.2g and ac3 = 6.95g in one direction while threshold accelerations in opposite direction are ac4 = 4.9g, ac5 = 8.47g and ac6 = 5.6g. The switch shows excellent threshold acceleration detection capability, and the inertial switch keeps open while the external acceleration is 0.2g less than the predefined threshold value. The experimental results show that the threshold acceleration with specific pulse width can be accurately identified, and the switch can bear strong overload acceleration comparing to traditional switches. Consequently, the proposed design method provides a new way for intelligent mechanical inertial sensors.

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