Layout Optimization Research Articles

Automated Layout Design of Hydraulic Components With Constraints on Flow Channels

Abstract The lightweight design of hydraulic equipment has always been of vital interest. Additive manufacturing (AM) technology can meet the manufacturing requirements of heteroideus and lightweight hydraulic equipment. However, traditional layout optimization often cannot satisfy the functional constraints of hydraulic components. This article proposes a design method of function-based automatic layout optimization for hydraulic components to solve this problem. The proposed method combines multi-component layout optimization with flow-up channel path planning and uses the triangular mesh model of hydraulic components directly as layout units. The spatial pose of the layout unit is used as the gene sequence for a genetic algorithm (GA). To meet the functional constraints, this study also proposes a fast, accurate collision detection algorithm for irregular 3D models and the generating strategy for follow-up flow channels. Here, the volume of the layout units, the total centroid radius of the layout plan, the length of flow channels, and the pressure loss are taken as the objective functions, and an automatic layout optimization algorithm for hydraulic components is developed. By optimizing the initial layout plan of an aviation electro-hydrostatic actuator (EHA), the characteristic volume of the optimized layout is reduced by 30.68% and the total length of the flow channels is decreased by 39.53%, demonstrating the efficiency of this method for lightweight hydraulic equipment design.

Design optimization of floating offshore wind farms using a steady state movement and flow model

Abstract In this study, we demonstrate how to carry out the design optimization of floating offshore wind farms by considering the impacts brought by the movements of the floating wind turbines. A steady state movement and flow model is applied in the modelling process. This model is developed by building a turbine surrogate model for estimating the steady state movement and power production of floating wind turbines and incorporating it in an open-source static wind farm simulator, PyWake. Using this modelling methodology, layout optimization problems of floating offshore wind farms are solved by using algorithms like Random Search to maximize the energy yield while satisfying certain constraints. Case studies are carried out for two wind farms with met-ocean conditions from a real planned site in Scottland to show the potential of layout optimization for floating wind farms.

Measuring and Predicting Multisensory Reaction Latency: A Probabilistic Model for Visual-Auditory Integration.

Virtual/augmented reality (VR/AR) devices offer both immersive imagery and sound. With those wide-field cues, we can simultaneously acquire and process visual and auditory signals to quickly identify objects, make decisions, and take action. While vision often takes precedence in perception, our visual sensitivity degrades in the periphery. In contrast, auditory sensitivity can exhibit an opposite trend due to the elevated interaural time difference. What occurs when these senses are simultaneously integrated, as is common in VR applications such as 360° video watching and immersive gaming? We present a computational and probabilistic model to predict VR users' reaction latency to visual-auditory multisensory targets. To this aim, we first conducted a psychophysical experiment in VR to measure the reaction latency by tracking the onset of eye movements. Experiments with numerical metrics and user studies with naturalistic scenarios showcase the model's accuracy and generalizability. Lastly, we discuss the potential applications, such as measuring the sufficiency of target appearance duration in immersive video playback, and suggesting the optimal spatial layouts for AR interface design.

Analysis of Grouting Stability in Composite Stratum Tunnels with Discontinuity Layout Optimization

Analysis of Grouting Stability in Composite Stratum Tunnels with Discontinuity Layout Optimization

An Optimization Method for Multi-Robot Automatic Welding Control Based on Particle Swarm Genetic Algorithm

This paper introduces an optimization method for multi-robot automated control welding based on a Particle Swarm Genetic Algorithm (PSGA), aiming to address issues such as high costs, large footprint, and excessive production cycles in multi-robot welding production lines. The method first constructs a multi-axis robotic kinematic model to provide constraint conditions. Then, the PSO (particle swarm optimization) algorithm, which integrates penalty functions into the fitness evaluation, is used to determine the optimal welding path by simulating collective behavior within a group. The GA (genetic algorithm) encodes the position of the welding robot bases into chromosomes to find the optimal layout for coordinated control of multiple robots. The entire process is optimized according to welding standards and requirements. Additionally, a comprehensive production line performance estimation model was used to quantitatively analyze the new scheme. The results show that the optimized production line’s balance rate increased by 10%, the balance loss rate decreased by 10%, the smoothness index increased by 37.8%, the space costs reduced by 44.4%, the equipment demand reduced by 41.1%, the labor demand reduced by 50%, the total costs reduced by 10%, and the average product cycle time was reduced by 5.07 s. Finally, we tested the algorithm in various complex scenarios and compared its performance against mainstream algorithms within the context of this study. The results demonstrated that the optimized production line significantly improved efficiency while maintaining safety standards.

Research of Design Technology of Printed Circuit Board

This paper delves into various methodologies for enhancing the quality, design, and optimization of Printed Circuit Boards (PCBs). With the development of the technology, the importance of Printed Circuit Board(PCB) is recently mentioned by more and more people who is trying to make progress of human technology. The classification of PCB defects, a crucial step in ensuring product reliability, is discussed on several categories of defects in PCB, highlighting recent advancements such as fuzzy c-means segmentation, which significantly improves defect detection accuracy. When producing, the layout is quite significant. In a conference, a group of scientists used a thermal layout modelling and optimization routine to make the board having more space to put circuit on it. Methods to ensure PCB quality during production are examined, focusing on optical and electrical testing. The PCB design process is also explored, emphasizing the importance of those considerations before production. Finally, the paper reviews innovative approaches to PCB layout optimization, particularly in managing heat dissipation and dynamic behavior through advanced simulation techniques.

A Research of the Integrated Circuit Design and Optimization

With the scientific and technical revolution going on, integrated circuit has been playing a vital role in our daily life ever since. In IC (Integrated circuit) design and manufacturing, layout of the integrated circuit determines its success or failure. However, the constantly decreasing characteristic size and progressive process bring about some new issues. That is why in post-Moore’s Law period, the design and optimization of layouts deserves attention of the whole industry. A properly designed and optimized layout not only results in better performance while using, but also cut out the cost of manufacture. In this paper, the methodology of integrated circuit layout design and optimization are discussed. For design, the author presented the whole flow of how the layout is generated and principles in integrated circuit design. For optimization, two approaches are analyzed. One is shorting out the critical area. Based on critical area theory and methodology of image processing, layouts can be improved in configuration. The method discussed here makes a modification on the previous way to make the optimization more accurate and efficient. The other method is inserting auxiliary polysilicon, which can counteract the impact of channel length change of MOSFETs and focus error as a unavoidable result of the process improvement.

Compliant Mechanism Synthesis Using Nonlinear Elastic Topology Optimization With Variable Boundary Conditions

ABSTRACTIn topology optimization of compliant mechanisms, the specific placement of boundary conditions strongly affects the resulting material distribution and performance of the design. At the same time, the most effective locations of the loads and supports are often difficult to find manually. This substantially limits topology optimization's effectiveness for many mechanism design problems. We remove this limitation by developing a method which automatically determines optimal positioning of a prescribed input displacement and a set of supports simultaneously with an optimal material layout. Using nonlinear elastic physics, we synthesize a variety of compliant mechanisms with large output displacements, snap‐through responses, and prescribed output paths, producing designs with significantly improved performance in every case tested. Compared to optimal designs generated using manually designed boundary conditions used in previous studies, the mechanisms presented in this paper see performance increases ranging from 47% to 380%. The results show that nonlinear mechanism responses may be particularly sensitive to boundary condition locations and that effective placements can be difficult to find without an automated method.

Analysis of Spatial Agglomeration Characteristics of Logistics Enterprises in Henan Province based on Poi

As an important industry connecting urban and rural areas and serving production and life, logistics enterprises, as the micro-foundation of the development of logistics industry, have a profound impact on the spatial reconstruction of regional economic and social development. National Development and Reform Commission issued the "Fourteenth Five-Year Plan" modern logistics development and "Fourteenth Five-Year Plan" modern circulation system construction planning "put forward new requirements for the development of logistics industry, emphasizing the optimization of logistics spatial layout and speed up the construction of national logistics hub, especially pointed out that to make up for the shortcomings of the central and western regions. As an important base for the development of China's logistics industry, the spatial layout of logistics enterprises in Henan province not only affects the high-quality development of the logistics industry in the province, but also plays an important role in the improvement of the national logistics network. In this paper, based on POI data, the mean nearest neighbor method, local Moran scatter plot analysis and kernel density visualization technology are used to analyze the spatial agglomeration characteristics of logistics enterprises in 157 counties in Henan Province. It is found that the spatial distribution of logistics enterprises in Henan Province has gradually evolved from multi-point dispersion to a single-core and multi-core collaborative model with Zhengzhou as the core, and presents a significant spatial positive correlation and agglomeration trend. This change has improved the logistics efficiency and promoted the strengthening of regional economic ties. At the same time, the agglomeration trend of logistics enterprises in Henan Province continues to strengthen, from the initial agglomeration in the core area to the diversified diffusion pattern, showing the continuous optimization and reconstruction of logistics network in the province.

FLOWERS AEP: An Analytical Model for Wind Farm Layout Optimization

ABSTRACTAnnual energy production (AEP) is commonly used in objective functions for wind farm layout optimization. AEP is proportional to wind farm power production integrated over an annual distribution of free‐stream wind conditions. Physics‐based estimates of wind farm power production typically rely on low‐fidelity engineering wake models that approximate the steady‐state wind farm flow field. AEP estimates are then obtained by performing independent simulations for discrete wind conditions and using rectangular quadrature to account for each condition's expected frequency of occurrence. Depending on the number of simulated discrete wind conditions, this numerical integral could be hampered by poor accuracy or high computational costs. The FLOWERS AEP model instead poses an analytical integral of the engineering wake model over the variable wind conditions, yielding a closed‐form, analytical function for wind farm AEP. This paper derives the analytical functions for FLOWERS AEP and its derivatives with respect to turbine position, which are useful for gradient‐based wind farm layout optimization, in nondimensional form. We then analyze the benefits of the FLOWERS AEP model over conventional reference models, focusing on its low cost, adequate wake loss predictions, and smooth design space. Although the FLOWERS approach is found to predict the exact value of AEP with some error relative to the reference model (within 14% on average), it dramatically reduces computation time by an order of magnitude, produces a qualitatively similar design space at relatively low resolution, and yields comparable optimal layouts. This significant speed improvement is critical in layout optimization applications, where determining an optimal layout in an efficient manner is more important than precise AEP prediction.

Thermal modelling and layout optimization of GaN half-bridge IC with integrated drivers and power HEMTs

The paper presents the results of thermal modeling of a half-bridge monolithic integrated circuit (IC) with integrated drivers and enhanced mode power high electron mobility transistors, based on a GaN-on-SOI heterostructure. It had been established that the main heat sources in the IC were the half-bridge GaN HEMTs. The heat from the half-bridge GaN HEMTs propagates in the chip and leads to heating of the logic block and gate drivers. Heating of half-bridge GaN HEMTs leads to increased channel resistance and IC output current drop. Heating of the gate drivers reduces driving current, as a result, increases the switching time of the half-bridge GaN HEMTs. Heating of the logic block increases the rise and fall times of the generated control signals, which worsens the dynamic characteristics of the IC. A comparative analysis of heat propagation for IC dies based on GaN-on-SOI and GaN-on-Si heterostructures showed that GaN-on-SOI structure has a 40% greater junction-to-backside thermal resistivity compared to GaN-on-Si structure. In this case, the specific thermal resistance in the direction of heat propagation from the hotspot of the transistor to the backside of the die for the GaN-on-SOI structure is almost two orders of magnitude greater than in the direction of its propagation to the frontside of the chip. The results obtained were used for IC layout optimization. The rearrangement of GaN-on-SOI IC functional blocks, as well as to introduction of additional heat-spreading elements on the frontside of chip were carried out during the optimization.

Design of gas control lane of 9# coal seam in Wuhushan Mine based on layer layout optimization

In order to address the issue of gas over limit in the upper corner of the working face of the 9# coal seam in Wuhushan Mine, a series of theoretical and numerical simulation analyses were conducted to evaluate the optimal configuration for the gas control lane of the 9# coal seam. In accordance with the "O" circle theory and the lithology of the overlying rock strata of the 9# coal seam, the height range of the fallout zone and fissure zone in the working face mining area was determined by employing empirical formulas. The change rule and distribution characteristics of the porosity of the fissure zone and the fall zone in the mining area were analyzed based on the characteristics of rock movement and fall. The determination method was also provided. The numerical simulation software was employed to simulate and analyze the gas concentration field in the air-mining zone under conditions of no extraction and six distinct layer positions of the gas control lane. The optimal layer position of the gas control lane in the 9# coal seam was determined and subsequently implemented in the field. The results demonstrate that the overlying rock layer in the 9# coal seam exhibits a height range of 6.86 ~ 11.26 m, while the fissure zone displays a height range of 30.11 ~ 41.31 m. When the gas control road is situated in close proximity to the working face, the gas concentration field exhibits a markedly low concentration. When the distance between the gas control lane and the return airway of the working face is 20 m and the distance from the top of the coal seam is 20 m, the gas concentration in the upper corner and the return airway is 0.35% and 0.26%, respectively. These values are close to the lowest concentration observed in the layout scheme. Additionally, the gas extraction concentration and the pure volume of the gas control lane are 23.7% and 38.3 m3 min−1, respectively. These values represent the highest concentrations observed in the various layout schemes. The application of the gas management lane in the field, based on the numerical simulation results, demonstrated a successful extraction effect, which was consistent with the numerical simulation results. This effectively managed the issue of an over-limit of gas in the upper corner of the working face of the 9# coal seam.

Land acquisition and storage strategy and optimization of urban spatial layout

This article explores the relationship between land acquisition and storage strategies and optimization of urban spatial layout. By analyzing the current situation, challenges, and strategies for high-quality development requirements of land reserves, a logical approach for the preparation of land reserve planning has been proposed. Based on the actual case of Jinan City, Shandong Province, this paper summarizes the implementation effect of land reserve planning and looks forward to the future development direction.

The Impact of Different Types of Trees on Annual Thermal Comfort in Hot Summer and Cold Winter Areas

Trees positively improve the annual thermal comfort of the built environment in tropical areas, where climate change is slight throughout the year. However, for areas with high changes in climate all year, the current studies have only explored the summer cooling performance of trees without the impact of different types of trees on annual thermal comfort, especially in cold seasons. Therefore, to quantify the impacts and scientifically guide the optimization of green space layout in hot summer and cold winter areas, this study selected Changsha City as the study area and analyzed how the annual thermal comfort is affected by evergreen trees and deciduous trees, which are two common types of trees in hot summer and cold winter areas. The analytical results indicated that the difference in the effect of deciduous and evergreen trees on outdoor thermal comfort was insignificant in summer, where the difference in the monthly mean PET for the three summer months was slight, being 0.28 °C, 0.14 °C, and 0.29 °C, respectively. However, evergreen trees greatly exacerbated winter cold compared to deciduous trees, with a monthly mean PET decrease by nearly 1.0 °C and an hourly PET reduced by up to 3.57 °C. The difference is mainly attributed to the absorption and reflection of solar radiation by the tree canopy, as well as the cooling and humidifying effect of the tree leaf. In hot summer and cold winter areas, outdoor thermal comfort is still in the “comfortable” and “slightly warm” acceptable stage despite the warming effect of deciduous trees in the spring and autumn seasons. Planting evergreen trees is an inevitable thermal mitigation choice for tropical areas. However, for the areas with high annual climate change, such as hot summer and cold winter areas in China, a change in empirical tree planting patterns and selecting deciduous trees where appropriate will improve year-round outdoor thermal comfort.

Optimization of Truck–Cargo Matching for the LTL Logistics Hub Based on Three-Dimensional Pallet Loading

This study investigates the truck–cargo matching problem in less-than-truckload (LTL) logistics hubs, focusing on optimizing the three-dimensional loading of goods onto standardized pallets and assigning these loaded pallets to a fleet of heterogeneous vehicles. A two-stage hybrid heuristic algorithm is proposed to solve this complex logistics challenge. In the first stage, a tree search algorithm based on residual space is developed to determine the optimal layout for the 3D loading of cargo onto pallets. In the second stage, a heuristic online truck–cargo matching algorithm is introduced to allocate loaded pallets to trucks while optimizing the number of trucks used and minimizing transportation costs. The algorithm operates within a rolling time horizon, allowing it to dynamically handle real-time order arrivals and time window constraints. Numerical experiments demonstrate that the proposed method achieves high pallet loading efficiency (close to 90%), near-optimal truck utilization (nearly 95%), and significant cost reductions, making it a practical solution for real-world LTL logistics operations.

Refined Identification of Urban Functional Zones Integrating Multisource Data Features: A Case Study of Lanzhou, China

Identifying urban functional zones is one of the important foundational activities for urban renewal and the development of high-quality urban areas. Efficient and accurate identification methods for urban functional zones are significant for smart city planning and industrial layout optimization. However, existing studies have not adequately considered the impact of the interactions between human activities and geographical space provision on the delineation of urban functional zones. Therefore, from the perspective of integrating the spatiotemporal characteristics of human activities with the distribution of urban functional facilities, by incorporating mobile signaling, POI (point of interest), and building outline data, we propose a multifactorial weighted kernel density model that integrates ‘human activity–land feature area–public awareness’ to delineate urban functional zones quantitatively. The results show that the urban functional zones in the central city area of Lanzhou are primarily characterized by dominant single functional zones nested within mixed functional zones, forming a spatial pattern of ‘single–mixed’ synergistic development. Mixed function zones are widely distributed in the center of Lanzhou City. However, the area accounted for a relatively small proportion, the overall degree of functional mixing is not high, and the inter-district differences are obvious. The confusion matrix showed 85% accuracy and a Kappa coefficient of 0.83.

A novel framework for automated warehouse layout generation.

Optimizing warehouse layouts is crucial due to its significant impact on efficiency and productivity. We present an AI-driven framework for automated warehouse layout generation. This framework employs constrained beam search to derive optimal layouts within given spatial parameters, adhering to all functional requirements. The feasibility of the generated layouts is verified based on criteria such as item accessibility, required minimum clearances, and aisle connectivity. A scoring function is then used to evaluate the feasible layouts considering the number of storage locations, access points, and accessibility costs. We demonstrate our method's ability to produce feasible, optimal layouts for a variety of warehouse dimensions and shapes, diverse door placements, and interconnections. This approach, currently being prepared for deployment, will enable human designers to rapidly explore and confirm options, facilitating the selection of the most appropriate layout for their use-case.

Deformation Reconstruction and Sensor Optimal Layout of Large-Span Spatial Structures Based on the Kalman Filter Method

Deformation Reconstruction and Sensor Optimal Layout of Large-Span Spatial Structures Based on the Kalman Filter Method

Full-scale test of disc cutter rotary cutting in TBM tunnelling: a case study of Mawan granite in Shenzhen, China

Understanding the distribution of cutting force provides a foundation for the design and optimization of cutterhead layout. The simulation of rotary cutting with a large cutting radius remains a challenge for laboratory tests. In this study, taking the driving condition of the Mawan Tunnel located in the Guangdong-Hong Kong-Macao Greater Bay Area as a case study, a full-scale rotary cutting platform with large cutting radius was used to investigate the rock-breaking effects. Rotary cutting with cutting depths of 1–8 mm and cutting radii of 200–1400 mm were carried out on the granite testing platform using a 19-in disc cutter. The normal force, rolling force, and side force during the cutting process were systematically monitored. Moreover, the time–frequency characteristics of the rock breaking process and the effects of cutting depth, cutting radius and stress state on the average and peak loads were investigated. The results show that the average normal force and rolling force increased with increasing cutting depth, while the side force was less affected by cutting depth through the Boltzman model analysis. The average normal force and rolling force were not significantly affected by the cutting radius, but the average side force decreased as a power function with increasing cutting radius, and showed a stable side force when the installation radius exceeded 1000 mm. The dominant frequency of the cutting force was 0–1.2 Hz, exhibiting notable low-frequency characteristics. Additionally, the ratio of peak to average (RPA) with respect to triaxial cutting force demonstrated an increase with the growth of cutting depth, while RPA in terms of side force exhibited a corresponding growth with the increasing cutting radius. In particular, the cutting force characteristics of the cutterhead obtained in this study can inform the layout of disc cutters and real-life TBM operations, thereby avoiding severe overloading of internal disc cutters.

Synchronization Optimization of Pipeline Layout and Pipe Diameter Selection in a Drip Irrigation Network System Based on the Jaya Algorithm

To address the complexity and high computational burden in the design of drip irrigation networks, the Jaya algorithm is utilized to study factors affecting project costs, including equipment and pipeline depreciation and the operation and management costs of the irrigation area. A mathematical model of synchronization optimal design of pipe layout and pipe diameter selection in a drip irrigation network system with constraints on pipe diameter, flow velocity, and pipe pressure is established. Using an irrigation district in Xinjiang, China, as an example, the Jaya algorithm optimization design program was run independently 50 times, and the relative deviation of each optimization result from the optimal solution was calculated. The results show that the annual cost per unit area o is reduced to 635.99 RMB/hm2, a 25.34% reduction compared to the original engineering program, and the investment-saving effect is obvious. The relative deviation is controlled within 3%, which shows that the algorithm has stable convergence performance and can meet the requirements of actual engineering design. The Jaya algorithm eliminates the need for parameter tuning, and it excels in cost savings, algorithm stability, and computational accuracy, making it an effective method for the single-objective optimization design of drip irrigation networks.