scholarly journals Control at stability's edge minimizes energetic costs: expert stick balancing

2016 ◽  
Vol 13 (119) ◽  
pp. 20160212 ◽  
Author(s):  
John Milton ◽  
Ryan Meyer ◽  
Max Zhvanetsky ◽  
Sarah Ridge ◽  
Tamás Insperger
Keyword(s):  
Time Delay ◽  
Balance Control ◽  
Dead Zone ◽  
Minimum Energy ◽  
Motor Task ◽  
Vertical Displacement ◽  
Energy Expenditures ◽  
Switching Type ◽  
Displacement Angle ◽  
The Cost

Stick balancing on the fingertip is a complex voluntary motor task that requires the stabilization of an unstable system. For seated expert stick balancers, the time delay is 0.23 s, the shortest stick that can be balanced for 240 s is 0.32 m and there is a ° dead zone for the estimation of the vertical displacement angle in the saggital plane. These observations motivate a switching-type, pendulum–cart model for balance control which uses an internal model to compensate for the time delay by predicting the sensory consequences of the stick's movements. Numerical simulations using the semi-discretization method suggest that the feedback gains are tuned near the edge of stability. For these choices of the feedback gains, the cost function which takes into account the position of the fingertip and the corrective forces is minimized. Thus, expert stick balancers optimize control with a combination of quick manoeuvrability and minimum energy expenditures.

Modelling Stick Balancing by Applying Switching-Type Control

2020 ◽  
Author(s):  
Dalma J. Nagy ◽  
László Bencsik ◽  
Tamás Insperger
Keyword(s):  
Balance Control ◽  
Dead Zone ◽  
Human Perception ◽  
Dynamical Behaviour ◽  
Point Of View ◽  
Control Force ◽  
Delay Compensation ◽  
Switching Type ◽  
Human Balance ◽  
The Brain

Abstract In today’s aging society special attention is devoted to the research of human balance control. Our research group focuses on understanding the control mechanism of the brain during balancing from an engineering point of view. The model of stick balancing is derived and the dynamical behaviour of the mechanical system is investigated numerically. The control force is modelled as a PD controller with predictor feedback without implementation uncertainty, which allows perfect delay compensation. However, the sensory dead zone of human perception is also accounted for in the model and thus, a delayed switching-type controller is applied. After deriving the mechanical model, numerical analysis is carried out in order to investigate the effect of time delay and the size of sensory dead zones.

Scaling laws of vascular trees: of form and function

2006 ◽  
Vol 290 (2) ◽  
pp. H894-H903 ◽  
Author(s):  
Ghassan S. Kassab
Keyword(s):  
Flow Rate ◽  
Scaling Laws ◽  
Minimum Energy ◽  
Blood Flow Rate ◽  
Tree Structure ◽  
Conservation Of Energy ◽  
Form And Function ◽  
And Function ◽  
The Cost ◽  
Vascular Trees

The branching pattern and vascular geometry of biological tree structure are complex. Here we show that the design of all vascular trees for which there exist morphometric data in the literature (e.g., coronary, pulmonary; vessels of various skeletal muscles, mesentery, omentum, and conjunctiva) obeys a set of scaling laws that are based on the hypothesis that the cost of construction of the tree structure and operation of fluid conduction is minimized. The laws consist of scaling relationships between 1) length and vascular volume of the tree, 2) lumen diameter and blood flow rate in each branch, and 3) diameter and length of vessel branches. The exponent of the diameter-flow rate relation is not necessarily equal to 3.0 as required by Murray's law but depends on the ratio of metabolic to viscous power dissipation of the tree of interest. The major significance of the present analysis is to show that the design of various vascular trees of different organs and species can be deduced on the basis of the minimum energy hypothesis and conservation of energy under steady-state conditions. The present study reveals the similarity of nature's scaling laws that dictate the design of various vascular trees and the underlying physical and physiological principles.

Adaptive decentralized NN control of large-scale stochastic nonlinear time-delay systems with unknown dead-zone inputs

2015 ◽  
Vol 158 ◽  
pp. 194-203 ◽  
Author(s):  
Guozeng Cui ◽  
Zhen Wang ◽  
Guangming Zhuang ◽  
Ze Li ◽  
Yuming Chu
Keyword(s):  
Time Delay ◽  
Large Scale ◽  
Dead Zone ◽  
Delay Systems ◽  
Time Delay Systems

From Construction to Operation: Achieving Indoor Thermal Comfort via Altering External Walls Specifications in Egypt

2013 ◽  
Vol 689 ◽  
pp. 250-253 ◽  
Author(s):  
Mohamed M. Mahdy ◽  
Marialena Nikolopoulou
Keyword(s):  
Energy Consumption ◽  
Thermal Comfort ◽  
Natural Ventilation ◽  
Minimum Energy ◽  
Residential Energy ◽  
Indoor Thermal Comfort ◽  
Minimum Energy Consumption ◽  
Different Types ◽  
Running Cost ◽  
The Cost

The objective of this research is to study the effect of using different material specifications for the external walls on the cost of the energy consumption for achieving internal thermal comfort. We refer to this as operation running cost, which in turn is compared to initial construction cost for each type of the used external walls. In order to achieve this objective, dynamic thermal simulation were carried out for four different types of external walls – commonly used in Egypt – in two different sets of cooling: natural ventilation and mechanical means. Experiments recommend that using the Egyptian Residential Energy Code (EREC) to achieve inner thermal comfort with the minimum energy consumption (consequently the minimum CO2 emissions) and the minimum running cost as well.

Load Balancing and Prudential Hypervisor in Cloud Computing

2019 ◽  
pp. 196-214
Author(s):  
G. Soniya Priyatharsini ◽  
N. Malarvizhi
Keyword(s):  
Cloud Computing ◽  
Time Delay ◽  
Load Balancing ◽  
Service Time ◽  
Service Model ◽  
The Cost ◽  
Cloud Users ◽  
Available Resources

Cloud computing is a service model in internet that provides virtualized resources to its clients. These types of servicing give a lot of benefits to the cloud users where they can pay as per their use. Even though they have benefits, they also face some problems like receiving computing resources, which is guaranteed on time. This time delay may affect the service time and the makespan. Thus, to reduce such problems, it is necessary to schedule the resources and then allocate it to using an optimized hypervisor. Here, the proposed method is used to do the above-mentioned problem. First, the available resources are clustered with respect to their characteristics. Then the resources are scheduled using this method. Finally, with respect to that of the clients request the resources, the resources are allocated. Here, the cost is the fitness of the allocation.

scholarly journals A Long-term Strategy for Energy and Cost Performance Improvement of Existing Residential Buildings: Step-by-step Renovation in Turkey

2019 ◽  
Vol 111 ◽  
pp. 03040
Author(s):  
Touraj Ashrafian ◽  
Zerrin Yilmaz ◽  
Nazanin Moazzen
Keyword(s):  
Cost Analysis ◽  
Energy Efficient ◽  
Financial Incentives ◽  
Residential Buildings ◽  
Minimum Energy ◽  
Energy Performance ◽  
Optimal Level ◽  
Proper Solution ◽  
Existing Building ◽  
The Cost

Recast version of Energy Performance of Building Directive (EPBD-Recast) obligate member states to keep the cost analysis in parallel with the energy analysis during the renovation actions for the existing building by taking the cost-optimal level of minimum energy performance requirement to the account. Although this cost-optimal level is indicating the minimum cost level for a period, it can provide buildings’ owners with an enormous initial cost. One of the most challenging barriers to energy efficient and cost-optimal renovation of existing buildings is the reluctance of owners to involve in their project as an investor due to the high cost of application. Particularly in developing countries, such reluctance is more tangible as the governments are not capable of providing enough financial incentives for owners due to a large number of buildings that should be renovated and small available budget. A proper solution for the problem is to divide necessary actions for each building to certain sub-actions and apply them as a step-by-step renovation project. On the other hand, the progressive application of renovation activities has some restrictions. It is necessary to define the due amount for households and keep the cost of each step within the payable range. Moreover, the low rate of building renovation which affects the EU goals can be improved remarkably by application of step-by-step actions not only by increasing the number of owners’ contributions but also by improving the time of implementation, proper distribution of skilled labours and directed economic resources. This paper aims to assess the step-by-step application of the energy efficient renovation actions through energy and cost analysis under Turkey’s climatic, economic and sociological conditions. One of 26 reference residential buildings in Turkey is analysed in this paper. The due amount for each step is defined, and some renovation actions and their combinations applied to the case building and the results compared with the base condition. Then a proper combination of measures established based on the cost-optimal analyses. These appropriately combined actions are then divided into some sub-actions; following this, cost and energy studies are conducted again to determine the appropriate arrangement of sub-actions.

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