A Study on the Influence of Planar Mechanism Design on Energy Use During Controlled Movements

Author(s):  
David H. Myszka ◽  
Austin M. Fischer ◽  
Andrew P. Murray

This paper presents a study on the energy utilization of planar automation mechanisms that operate with controlled moves. Designers of factory automation for pick & place tasks often select multiple degree-of-freedom robotic devices. With multiple degrees-of-freedom, task flexibility is available, but many operations require little or no flexibility. The majority of research on the energy usage of these robot devices for pick & place tasks focuses on path planning. The study presented in this paper explores the energy savings in using low degree-of-freedom devices and the influence of design parameter selection. Energy predictor equations are developed and confirmed through experimentation. Various positioning mechanisms of differing dimensions are studied for trends in energy utilization. Lastly, an actuator control strategy is proposed for further reducing energy requirements. The study concludes that energy usage can be substantially decreased in pick & place applications by reducing the degrees of freedom of the device, implementing a prudent mechanism architecture, ideally selecting mechanism dimensions and optimally controlling the actuator(s).

2021 ◽  
Author(s):  
Yu SUN ◽  
Jinsong Zhou ◽  
Dao Gong ◽  
Yuanjin Ji

Abstract To absorb the vibration of the carbody of the high-speed train in multiple degrees of freedom, a multi-degree of freedom dynamic vibration absorber (MDOF DVA) is proposed. Installed under the carbody, the natural vibration frequency of the MDOF DVA from each DOF can be designed as a DVA for each single degree of freedom of the carbody. Hence, a 12-DOF model including the main vibration system and a MDOF DVA is established, and the principle of Multi-DOF dynamic vibration absorption is analyzed by combining the design method of single DVA and genetic algorithm. Based on a high-speed train dynamics model including an under-carbody MDOF DVA, the vibration control effect on each DOF of the MDOF DVA is analyzed by the virtual excitation method. Moreover, a high static and low dynamic stiffness (HSLDS) mount is proposed based on a cam–roller–spring mechanism for the installation of the MDOF DVA due to the requirement of the low vertical dynamic stiffness. From the dynamic simulation of a non-linear model in time-domain, the vibration control performance of the MDOF DVA installed with nonlinear HSLDS mount on the carbody is analyzed. The results show that the MDOF DVA can absorb the vibration of the carbody in multiple degrees of freedom effectively, and improve the running ride quality of the vehicle.


Energies ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1480 ◽  
Author(s):  
Qadeer Ali ◽  
Muhammad Jamaluddin Thaheem ◽  
Fahim Ullah ◽  
Samad M. E. Sepasgozar

Rising demand and limited production of electricity are instrumental in spreading the awareness of cautious energy use, leading to the global demand for energy-efficient buildings. This compels the construction industry to smartly design and effectively construct these buildings to ensure energy performance as per design expectations. However, the research tells a different tale: energy-efficient buildings have performance issues. Among several reasons behind the energy performance gap, occupant behavior is critical. The occupant behavior is dynamic and changes over time under formal and informal influences, but the traditional energy simulation programs assume it as static throughout the occupancy. Effective behavioral interventions can lead to optimized energy use. To find out the energy-saving potential based on simulated modified behavior, this study gathers primary building and occupant data from three energy-efficient office buildings in major cities of Pakistan and categorizes the occupants into high, medium, and low energy consumers. Additionally, agent-based modeling simulates the change in occupant behavior under the direct and indirect interventions over a three-year period. Finally, energy savings are quantified to highlight a 25.4% potential over the simulation period. This is a unique attempt at quantifying the potential impact on energy usage due to behavior modification which will help facility managers to plan and execute necessary interventions and software experts to develop effective tools to model the dynamic usage behavior. This will also help policymakers in devising subtle but effective behavior training strategies to reduce energy usage. Such behavioral retrofitting comes at a much lower cost than the physical or technological retrofit options to achieve the same purpose and this study establishes the foundation for it.


Author(s):  
Yan Chen ◽  
Huijuan Feng ◽  
Jiayao Ma ◽  
Rui Peng ◽  
Zhong You

The traditional waterbomb origami, produced from a pattern consisting of a series of vertices where six creases meet, is one of the most widely used origami patterns. From a rigid origami viewpoint, it generally has multiple degrees of freedom, but when the pattern is folded symmetrically, the mobility reduces to one. This paper presents a thorough kinematic investigation on symmetric folding of the waterbomb pattern. It has been found that the pattern can have two folding paths under certain circumstance. Moreover, the pattern can be used to fold thick panels. Not only do the additional constraints imposed to fold the thick panels lead to single degree of freedom folding, but the folding process is also kinematically equivalent to the origami of zero-thickness sheets. The findings pave the way for the pattern being readily used to fold deployable structures ranging from flat roofs to large solar panels.


2017 ◽  
Vol 7 (2) ◽  
pp. 185-198 ◽  
Author(s):  
Kamalesh Panthi ◽  
Kanchan Das ◽  
Tarek Abdel-Salam

Purpose Vacation rental homes, in general, have different energy usage characteristics than traditional residential homes mainly because of the occupancy pattern that changes on a weekly basis. These homes, predominantly larger in size, offer a greater scope for energy savings also because of the wasteful habits of their seasonal occupants. The purpose of this paper is to investigate the causes of energy inefficiencies prevalent in these homes so that appropriate retrofit choices can be offered to homeowners. Design/methodology/approach This research presents a case study of a vacation rental home whose energy consumption was investigated in depth and energy inefficiencies identified through modeling using energy modeling software, eQUEST. Simulations were performed to identify viable retrofit scenarios. Findings While improvement in the building envelope such as providing shades/overhangs on the windows, reducing infiltration and increasing insulation of the exterior wall did not show promising results for savings on energy cost, other improvements such as use of highly efficient lamps, tank-less water heater system and occupancy sensors showed viable investment options with shorter payback periods. It was also found that energy use intensity of sampled houses was about half of the average of US residential buildings, which could primarily be attributed to the seasonal nature of occupancy of these houses. Originality/value There is a dearth of literature pertaining to energy efficiency-related retrofits of coastal vacation homes. This research fills that gap to some extent by addressing this issue with an ultimate aim of assisting homeowners in retrofit decision-making.


Author(s):  
Joe Huang ◽  
Donghyun Seo ◽  
Moncef Krarti

The Changning District in Shanghai has expressed interest to becoming a green neighborhood and has asked for recommendations on how to reduce the energy usage in public buildings in their district. The objective of this short study is to identify the likely range of further reductions in the energy use and carbon emissions of new buildings through energy-efficiency improvements and the use of renewable energy, i.e., solar hot water (SHW), photovoltaics (PV), and ground-source heat pumps (GSHP), as compared to buildings that meet the current public building energy code in Shanghai. This analysis is done using DOE-2.1E computer simulations of three prototypical building models — an office, a hotel, and a mixed-use retail/office building — that have been calibrated against measured energy data from such buildings in the Changning District. After the building models have been calibrated, they are then used to establish the baseline energy use for code-compliant buildings, and to calculate the energy savings for 16 potential EEMs (Energy Efficiency Measures) that exceed the building energy code. A LCC (Life-Cycle Cost) analysis is done to compare the energy cost reductions to the capital costs for the EEMs, with the result that some EEMs are rejected as being not cost-effective over a 25 year period. The usage of the EEMs accepted as cost-effective is found to reduce the energy usage of the three building types by 30–40% in the office, 43–46% in the hotel, and 35% in the retail, depending on the assumed discount rate. If all the EEMs are considered regardless of cost, the energy savings increase to 44% in the office, 47% in the hotel, and 36% in the retail.


2019 ◽  
Vol 04 (02) ◽  
pp. 1950002
Author(s):  
Martin Klemm ◽  
Uwe D. Hanebeck ◽  
Harald Hoppe

Nowadays, robotic systems are an integral part of many orthopedic interventions. Stationary robots improve the accuracy but also require adapted surgical workflows. Handheld robotic devices (HHRDs), however, are easily integrated into existing workflows and represent a more economical solution. Their limited range of motion is compensated by the dexterity of the surgeon. This work presents control algorithms for HHRDs with multiple degrees of freedom (DOF). These algorithms protect pre- or intraoperatively defined regions from being penetrated by the end effector (e.g., a burr) by controlling the joints as well as the device’s power. Accuracy tests on a stationary prototype with three DOF show that the presented control algorithms produce results similar to those of stationary robots and much better results than conventional techniques. This work presents novel and innovative algorithms, which work robustly, accurately, and open up new opportunities for orthopedic interventions.


Author(s):  
Mate Antali ◽  
Denes Takacs ◽  
Gabor Stepan

In this paper, a special type of beam element is developed with three nodes and with only translational degrees-of-freedom (DOFs) at each node. This element can be used effectively to build low degree-of-freedom models of rotors. The initial model from the Bernoulli theory is fitted to experimental results by nonlinear optimization. This way, we can avoid the complex modeling of contact problems between the parts of squirrel cage rotors. The procedure is demonstrated on the modeling of a machine tool spindle.


2019 ◽  
Vol 4 (1) ◽  
pp. 69-74
Author(s):  
Christian Raymond Green ◽  
John I. Sodiki ◽  
Barinyima Nkoi

In this study, energy audit of a wheat processing plant in Rivers State, Nigeria has been carried out.  A walked-through energy audit method was undertaken to identify the major sources of energy in use, identify the lapses in energy usage, identify areas to improve energy usage, determine the level of energy consumption of the various energy sources and recommending policy measures that will enhance energy savings in the industry. The analysis showed that eight defined unit operations were required for the production of wheat flour; Truck Loading, Intake or Storage, Cleaning, Tempering or Conditioning, Holding Bin, Milling, Finished Product and Packaging. The types of energy used were electrical, thermal (diesel and gas), and manual energies with proportions of 14.63%, 85.31% and 0.05% respectively of total energy input. Average energy intensity was estimated to be 1.3GJ/tonnes for the production of wheat flour for the 5 years (2011-2015) study period. The most energy intensive operation was identified as the milling process with percentage energy input of 44.39% (123837.60MJ) followed by Finished Product Storage process with percentage energy input of 36.17% (100885.92MJ). It was observed that the industry under review did not sufficiently utilize energy as the energy used ratio is below 1. This was as a result of some factors that contributed to energy waste and energy use inefficiency in the industry. Among these factors are: electric motor that dissipate much heat, use of electric motors that have been rewound more than twice and generation of electricity more than needed in the industry by some generators. The exergy analysis showed that the roller dryer accounted for the major loss in the process with an inefficiency of 44.8%.  The useful work was 5.3kJ; exergy loss expended is 15.68kJ in the roller dryer. The study concluded that energy is not sufficiently utilized in the industry resulting in high energy waste and high pricing of wheat flour products.


2021 ◽  
Vol 13 (9) ◽  
pp. 4995
Author(s):  
Seongnoh Ahn ◽  
Gun Park ◽  
Hyungchul Yoon ◽  
Jae-Hyeok Han ◽  
Jongwon Jung

Modeling the soil–structure interaction (SSI) in seismic design involves the use of soil response curves for single-degree-of-freedom (SDOF) structures; however, real structures have multiple degrees of freedom (MDOF). In this study, shaking-table-derived p-y curves for SDOF and MDOF superstructures were compared using numerical analysis. It was found that an MDOF structure experienced less displacement than an SDOF structure of the same weight, but the effect of increasing the DOF decreased at greater pile depths. Numerical analysis results estimated using the natural periods and mass participation rates of the structures were similar to those of shaking table tests. Abbreviations: finite element: FE; frequency response function: FRF; multiple degrees of freedom: MDOF; single degree of freedom: SDOF; soil–structure interaction: SSI.


2012 ◽  
Vol 10 (07) ◽  
pp. 1250075 ◽  
Author(s):  
YING GUO ◽  
HONGYAN KUANG ◽  
DAZU HUANG ◽  
ZHISHENG ZHAO

We demonstrate two entanglement concentration protocols (ECPs) for photon pairs in less-hyperentanglement, the simultaneous entanglement in multiple degrees of freedom. Using these ECPs, some maximally entangled states in polarization can be reconstructed deterministically from less-hyperentangled ones shared between remote participants. Both of the success probabilities are 100% in principle, and they do not require additional single photons. The former is implemented with the passive linear optics, which is achievable with current technology. The later adopts the cross-Kerr nonlinearity media to complete this task, which can increase the efficiency of the entanglement concentration process since it does not require the sophisticated single-photon detectors for measurements. The two ECPs are useful for practical long-distance quantum communication due to the fact that the entangled state in either the spatial degree of freedom or the frequency degree of freedom suffers little from channel noise in optical fiber.


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