Proceedings of the Institution of Mechanical Engineers Part G-Journal of Aerospace Engineering最新文献_第4页

Deep reinforcement learning-based reactive trajectory planning method for UAVs 基于深度强化学习的无人飞行器反应式轨迹规划方法

IF 1.1 4区工程技术

Proceedings of the Institution of Mechanical Engineers Part G-Journal of Aerospace Engineering Pub Date : 2024-05-07 DOI: 10.1177/09544100241252233

Lijia Cao, Lin Wang, Yang Liu, Weihong Xu, Chuang Geng

{"title":"Deep reinforcement learning-based reactive trajectory planning method for UAVs","authors":"Lijia Cao, Lin Wang, Yang Liu, Weihong Xu, Chuang Geng","doi":"10.1177/09544100241252233","DOIUrl":"https://doi.org/10.1177/09544100241252233","url":null,"abstract":"In order to improve the ability of avoiding dynamic threats during the flight of unmanned aerial vehicles (UAVs), a deep reinforcement learning-based reactive trajectory planning method is proposed in this paper. Firstly, a constrained Rapidly-exploring Random Tree-Connect algorithm (C-RRT-Connect) is proposed as the basic algorithm of reactive trajectory planning to globally plan for avoiding static obstacles in the environment. The C-RRT-Connect algorithm introduces the idea of target attraction to constrain the optimal growth point in the RRT-Connect algorithm. Then, based on the global trajectory, the local optimization is carried out according to the dynamic threats detected by the UAV during the flight. According to the real-time relative state between the UAV and the detected dynamic threat, the reaction sampling points and directional coefficients for avoiding the corresponding dynamic threat are generated online via the action network trained with the depth deterministic policy gradient algorithm (DDPG). And then the local trajectory is adjusted to modify the flight trajectory of the UAV to achieve reactive obstacle avoidance. The simulation experiment firstly compares the global trajectory planning performance of C-RRT-Connect and RRT-Connect in static environment, and secondly compares the local trajectory planning performance of DDPG algorithm and the artificial potential field method in dynamic environment. The experimental results show that in static environment, C-RRT-Connect algorithm has faster searching speed, less invalid samples and higher searching trajectory quality than RRT-Connect algorithm; In a dynamic environment, DDPG algorithm reduces the average running time by about 26% compared with the artificial potential field method, and has a stronger ability to evade dynamic threats in real time.","PeriodicalId":54566,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part G-Journal of Aerospace Engineering","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140936438","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effects of rotational speed on transient cooling performance of nozzle spray with liquid nitrogen in a rotor-stator cavity 转速对转子-定子腔内液氮喷嘴喷雾瞬态冷却性能的影响

IF 1.1 4区工程技术

Proceedings of the Institution of Mechanical Engineers Part G-Journal of Aerospace Engineering Pub Date : 2024-05-07 DOI: 10.1177/09544100241251504

Xuesen Yang, Wei Zhao, Binglong Zhang, Sanqun Ren, Xiaorong Xiang, Qingjun Zhao

{"title":"Effects of rotational speed on transient cooling performance of nozzle spray with liquid nitrogen in a rotor-stator cavity","authors":"Xuesen Yang, Wei Zhao, Binglong Zhang, Sanqun Ren, Xiaorong Xiang, Qingjun Zhao","doi":"10.1177/09544100241251504","DOIUrl":"https://doi.org/10.1177/09544100241251504","url":null,"abstract":"This paper presents the results of an experimental investigation into the cooling performance of a rotor-stator cavity with liquid nitrogen spraying. The experiments were conducted under varying rotational Reynolds numbers ranging from 1.70 × 106 to 5.12 × 106. The effects of rotational speed on temperature drop rate are studied and compared in detail, as well as the heat transfer coefficient distribution. Sufficient data, such as heat flux, injection rate, and injection pressure, were collected to provide a basis for further study in explaining the spray and evaporation over the cavity. It was found that the cooling performance of the rotating disc is strongly affected by the rotational speed. The short-term period exhibits a peak cooling rate of 14°C/s, in contrast to the sustained cooling rate during the spray process at rotational speeds of 500r/min, which amounts to 0.9°C/s. The occurrence of cavitation and evaporation within the nozzle results in a reduction of flow coefficient and fluctuation of the injection differential pressure. The transient cooling performance is well-explained by the temperature changes and cooling-down time under different rotational speeds. The analysis of the heat transfer coefficient is further enhanced through an evaluation of the convective and conductive heat transfer rates using a one-dimensional theoretical approach. The average temperature of the disc is expected to decrease by 100°C within a time frame no longer than 120 s. Additionally, after a duration of 120 s, the average heat transfer rate on the cold side is anticipated to surpass 8000 W/(m·K).","PeriodicalId":54566,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part G-Journal of Aerospace Engineering","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140936245","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Influence of combinational distortion generator geometrical parameters on the steady and dynamic components of the total pressure distortion 组合失真发生器几何参数对总压力失真稳定和动态分量的影响

IF 1.1 4区工程技术

Proceedings of the Institution of Mechanical Engineers Part G-Journal of Aerospace Engineering Pub Date : 2024-05-02 DOI: 10.1177/09544100241248875

Enbo Sun, Haideng Zhang, Yun Wu, Lifu Zhang

{"title":"Influence of combinational distortion generator geometrical parameters on the steady and dynamic components of the total pressure distortion","authors":"Enbo Sun, Haideng Zhang, Yun Wu, Lifu Zhang","doi":"10.1177/09544100241248875","DOIUrl":"https://doi.org/10.1177/09544100241248875","url":null,"abstract":"To construct a method for designing a total pressure distortion generator with adjustable, steady, and dynamic components, we experimentally investigated the influences of combinational distortion generator geometrical parameters on the steady and dynamic components of the total pressure distortion based on an indraft wind tunnel. Different types of annular plates and cylindrical rods were installed upstream of a traditional baffle total pressure distortion generator; the total pressure distortion was then measured using rotatable total pressure rakes. The installation of cylindrical rods upstream of the baffle plate could maximally reduce the ratio of steady and dynamic components of total pressure distortion by 30%. Increasing the number and height of the rods, as well as the axial distance between the rod and baffle plate, were effective methods of reducing the steady components of total pressure distortion. Similarly, changing the geometrical parameters of the annular plate was also an effective method for adjusting the ratio of steady and dynamic components of total pressure distortion. The ratio of the steady and dynamic components of total pressure distortion first experienced a decrease and then increased variance law with the increase in the height and circumferential scale of the annular plate. During this procedure, the steady and dynamic components ratio of total pressure distortion could be maximally reduced by 24% and maximally increased by 20%.","PeriodicalId":54566,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part G-Journal of Aerospace Engineering","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140838362","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Output feedback control for hypersonic flight vehicles via distributed high-gain observer 通过分布式高增益观测器实现高超音速飞行器的输出反馈控制

IF 1.1 4区工程技术

Proceedings of the Institution of Mechanical Engineers Part G-Journal of Aerospace Engineering Pub Date : 2024-05-02 DOI: 10.1177/09544100241249346

Yuehui Ji, Jingwei Jiang, Junjie Liu, Qiang Gao

{"title":"Output feedback control for hypersonic flight vehicles via distributed high-gain observer","authors":"Yuehui Ji, Jingwei Jiang, Junjie Liu, Qiang Gao","doi":"10.1177/09544100241249346","DOIUrl":"https://doi.org/10.1177/09544100241249346","url":null,"abstract":"During the hypersonic flight process of rigid hypersonic flight vehicles (HFVs), the flight-path angle and angle of attack are usually small and sensitive to flight condition variation, the accurate measurements are difficult, subsequently the formulation of states observers is an urgent issue. A distributed high-gain observer is proposed to reconstruct the admissible system state dynamics based on limited measured output. First, a distributed observer is proposed for the cascade strict-feedback system to ensure the global convergence of the state estimation errors between the estimated state in each local observer and system states, for the prescribed system initial values. Second, the distributed high-gain observer-based nonlinear control is investigated on the longitudinal dynamics of HFVs with partial measurable states. The rigid body system dynamic is divided into the altitude subsystem and the velocity subsystem. In the altitude subsystem, the proposed distributed high-gain observer is formulated to exact estimate the flight-path angle and angle of attack, and then the back-stepping design is proposed for constructing the controllers. The nonlinear dynamic inversion controller is introduced to accomplish the velocity tracking. Finally, simulation examples are served to verify that the proposed output feedback control possesses the superior properties of high tracking performance, fast convergence of state estimation error and easy-implementation.","PeriodicalId":54566,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part G-Journal of Aerospace Engineering","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140838777","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effects of non-uniformity in thickness and volume fraction of nanofillers on the flutter characteristics of nanocomposite cantilever trapezoidal plates 纳米填料厚度和体积分数不均匀对纳米复合材料悬臂梯形板飘动特性的影响

IF 1.1 4区工程技术

Proceedings of the Institution of Mechanical Engineers Part G-Journal of Aerospace Engineering Pub Date : 2024-05-02 DOI: 10.1177/09544100241248196

Keivan Torabi, Hassan Afshari, Farhad Haji Aboutalebi

{"title":"Effects of non-uniformity in thickness and volume fraction of nanofillers on the flutter characteristics of nanocomposite cantilever trapezoidal plates","authors":"Keivan Torabi, Hassan Afshari, Farhad Haji Aboutalebi","doi":"10.1177/09544100241248196","DOIUrl":"https://doi.org/10.1177/09544100241248196","url":null,"abstract":"The aim of this work is to investigate the flutter characteristics of nanocomposite cantilever trapezoidal plates with non-uniform thickness enriched with either carbon nanotubes (CNTs), graphene nanoplatelets (GNPs), or graphene oxide powders (GOPs) which are distributed functionally graded (FG) in the axial direction. It is assumed that the thickness of the plate and the volume fraction of the nanofillers vary in one direction from the wider clamped edge of the plate to the outer narrower free one. The modeling of the plate is done using the first-order shear deformation theory (FSDT) and the aerodynamic pressure generated by the aerodynamic pressure is modeled using the linear approximation of the piston theory. The material properties of the plate are calculated using the mixing rule (ROM) and the Halpin–Tsai model. The governing equations and boundary conditions at the clamped and free edges of the plate are derived via Hamilton’s principle. An approximate solution is applied using the differential quadrature method (DQM) to calculate the natural frequencies and the damping ratios of the plate. Numerical examples show that it is possible to find an optimal thickness variation profile that provides the greatest aeroelastic stability. It is concluded that by considering the same value for the mass fractions of the nanofillers, the highest aeroelastic stability can be attained by utilizing the GNPs as the reinforcers. It is found that to attain further improvement in aeroelastic stability, most nanofillers should be distributed near the clamped edge and away from the outer free edge.","PeriodicalId":54566,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part G-Journal of Aerospace Engineering","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140838504","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A collaborative navigation integrity augmentation method with optimal dynamic partner selection 优化动态伙伴选择的协作导航完整性增强方法

IF 1.1 4区工程技术

Proceedings of the Institution of Mechanical Engineers Part G-Journal of Aerospace Engineering Pub Date : 2024-04-30 DOI: 10.1177/09544100241249625

Rong Wang, Xin Chen, Zhi Xiong, Huiyuan Zhang, Jianye Liu, Xiaoyi Chen

{"title":"A collaborative navigation integrity augmentation method with optimal dynamic partner selection","authors":"Rong Wang, Xin Chen, Zhi Xiong, Huiyuan Zhang, Jianye Liu, Xiaoyi Chen","doi":"10.1177/09544100241249625","DOIUrl":"https://doi.org/10.1177/09544100241249625","url":null,"abstract":"The collaboration among swarmed aircraft can provide additional observation to improve the integrity of its onboard navigation systems. But due to the limitation on relative communicating and measuring burdens, adopting all the observations between aircraft in the swarm is inefficient. The geometry of the collaborated partners is a key factor that influences the effectiveness of the navigation integrity augmentation, which needs to be optimized in collaborative integrity augmented navigation. In this paper, the integrity augmented navigation method for aerial swarm based on collaborative partner optimization is proposed. The geometry constructed by the GNSS satellites and the cooperative partners in the aerial swarm are analyzed dynamically, and the augmented integrity protection levels with different collaborative relationships are predicted to distinguish the partner essential for navigation integrity augmentation. Then the collaborative partner makes a key contribution to integrity augmentation adopted in collaborative navigation integrity monitoring, improving the efficiency of the collaborative navigation. The simulation results indicate the effectiveness of the proposed cooperative partnership optimization strategy, as well as the superiority of the proposed method compared with the traditional independent integrity framework in improving the integrity protection level and fault detection capacity.","PeriodicalId":54566,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part G-Journal of Aerospace Engineering","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140838360","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Velocity-free fixed-time attitude tracking fault-tolerant control for rigid spacecraft based on the homogeneity method 基于同质性方法的刚性航天器无速度固定时间姿态跟踪容错控制

IF 1.1 4区工程技术

Proceedings of the Institution of Mechanical Engineers Part G-Journal of Aerospace Engineering Pub Date : 2024-04-27 DOI: 10.1177/09544100241249882

Zheng Yin, Zhang He, Wang Yan

引用次数: 0

Coupling optimization design of configuration and swept-bowed effects in highly loaded subsonic compressor tandem cascades with tip clearance 高负载亚音速压缩机串联级联中的配置和扫掠效应的耦合优化设计（带顶端间隙

IF 1.1 4区工程技术

Proceedings of the Institution of Mechanical Engineers Part G-Journal of Aerospace Engineering Pub Date : 2024-04-20 DOI: 10.1177/09544100241248195

Xiaochen Mao, Yingchen Jiao, Hao Cheng, Botao Zhang, Bo Liu

{"title":"Coupling optimization design of configuration and swept-bowed effects in highly loaded subsonic compressor tandem cascades with tip clearance","authors":"Xiaochen Mao, Yingchen Jiao, Hao Cheng, Botao Zhang, Bo Liu","doi":"10.1177/09544100241248195","DOIUrl":"https://doi.org/10.1177/09544100241248195","url":null,"abstract":"The coupling optimization design for swept-bowed effects and configuration of tandem cascade is conducted in a highly loaded subsonic compressor tandem cascade, in which the novelty lies in considering the spanwise distribution of configuration parameters and exploring the coupling relationship between them and swept-bowed design. Research results show that, compared with the original one, the loss coefficient of the optimal tandem cascade is decreased by 38.7% at the 4° incidence angle and the range of available incidence angle expands by 25%. For the distribution of the configuration parameters, parameters at the hub are significantly different from those near the tip, which confirms the tandem blade design in compressors is complex and needs to consider 3D flow effect. Forward swept and positive bowed design are beneficial for reducing loss at tip and alleviating the blockage, which cannot be achieved by the optimization only for configuration parameters. In terms of the weak coupling relationship between configuration parameters distribution and swept-bowed effects, the former should be considered first in practical engineering.","PeriodicalId":54566,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part G-Journal of Aerospace Engineering","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140628650","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Inverse dynamics based aerodynamic, gyroscopic, and rotor effects’ compensation in constrained trajectory synthesis for multi-copters 多旋翼飞行器受限轨迹合成中基于反动力学的气动、陀螺和旋翼效应补偿

IF 1.1 4区工程技术

Proceedings of the Institution of Mechanical Engineers Part G-Journal of Aerospace Engineering Pub Date : 2024-04-03 DOI: 10.1177/09544100241244816

Tsung-Liang Liu, Kamesh Subbarao

引用次数: 0

Novel integrated guidance and control design for a three-stage satellite carrier using model-free adaptive control 利用无模型自适应控制为三级卫星运载器设计新颖的综合制导和控制装置

IF 1.1 4区工程技术

Proceedings of the Institution of Mechanical Engineers Part G-Journal of Aerospace Engineering Pub Date : 2024-03-27 DOI: 10.1177/09544100221107507

Mohammadreza Yaseri, Alireza Basohbat Novinzadeh

引用次数: 0