An integrated control and structural design approach for mesh reflector deployable space antennas

An integrated control and structural design approach for mesh reflector deployable space antennas is presented in this paper. The coupled relationship of the antenna structure, deployment trajectory, and control system is discussed, and then the integrated design model is proposed. A multi-objective function is set to simultaneously minimize the antenna mass, the impact on antenna, and the energy dissipation of control system. The cross section areas of links, Bezier control points, and controller gain parameters are selected as the design variables. With the eigenfrequency, rigidity, stability, rapidity and accuracy constraints, the optimal integrated design is achieved. The highly nonlinear characteristic of this problem is discussed and corresponding solving strategy and methodology are described. Experiments are carried out to verify the rationality and validity of the structural analysis models and the control algorithm. Numerical simulations demonstrate the feasibility of the proposed design method.     

Task-specific optimal simultaneous kinematic, dynamic, and controldesign of high-performance robotic systems

A task-specific optimal simultaneous kinematic, dynamic and control design approach is proposed for high-performance computer-controlled machines, such as robots. This mechatronics design approach is based on the trajectory pattern method and a fundamentally new design philosophy that such machines, in general, and ultrahigh-performance machines, in particular, must only be designed to perform a class or classes of motions effectively. In the proposed approach, given the structure of the manipulator, its kinematic, dynamic, and control parameters are optimized simultaneously with the parameters that describe a selected trajectory pattern with which the desired class(es) of task(s) can best be performed. In one example, a weighted sum of the norms of the higher harmonics appearing in the actuating torques and the integral of the position and velocity tracking errors are used to form the optimality criterion. The selected optimality criterion should yield a system that is optimally designed to accurately follow the specified trajectory at high speed. Other objective functions can be readily formulated to synthesize systems for optimal performance. Based on the developed design methodology, a two-degrees-of-freedom robot manipulator with a closed-loop chain is optimally designed and constructed for point-to-point motions. The preliminary results of experiments indicate that the robot can, in fact, execute point-to-point motions rapidly and with minimal residual vibration. The potentials of the developed method and its implementation for generally defined motion patterns are discussed     

SAR Sensor Trajectory Deviations: Fourier Domain Formulation and Extended Scene Simulation of Raw Signal

Synthetic aperture radar (SAR) raw signal simulation is a useful tool for SAR system design, mission planning, processing algorithm testing, and inversion algorithm design. A two-dimensional (2-D) Fourier domain SAR raw signal simulator, exploiting the efficiency of fast Fourier transform algorithms, has been presented some years ago and is able to generate the raw signal corresponding to extended scenes. However, it cannot account for the effects of sensor trajectory deviations with respect to the nominal straight-line path. This paper explores the possibility of extending the efficient Fourier domain simulation approach to the case of sensor trajectory deviations, which is more realistic for airborne SAR systems. We first of all obtain a general and compact Fourier domain formulation of the SAR raw signal in the presence of arbitrary trajectory deviations, and show that in this general case no efficient simulation scheme can be devised. However, we demonstrate that, if a narrow beam and slow trajectory deviation assumption is made, a full 2-D Fourier domain simulation can be used. This approach can be applied only to some SAR systems and/or trajectory deviations, but it has the advantage that processing time is practically not increased with respect to the nominal trajectory case. The validity limits of the approach are analytically evaluated. Some simulation results are finally presented in order to verify the effectiveness of the proposed simulation scheme. In another paper, which is the second part of this work, it will be shown that the narrow beam–slow deviation assumption can be relaxed, at the expense of computation efficiency, if a one-dimensional azimuth Fourier domain processing followed by a range time-domain integration is used.     

星光导航成像的气动光学效应影响研究

给出了针对吸气式高超声速飞行器（ABHV）的飞推一体化参考轨迹,分析了其对星光导航成像影响。基于吸气式高超声速飞行器强耦合特性,结合星光成像导航技术特点,以飞推耦合度最小为优化指标,考虑ABHV的攻角、燃油当量比、攻角变化率和隔离段激波串位置等多约束特性,采用一种多约束最优化方法,得到了适合星光导航应用的参考轨迹,并分析了该轨迹下星光成像性能退化情况,进一步挖掘了发动机稳定工作和飞行器高精度打击等具有核心竞争力的总体性能指标的潜力。以某型ABHV为例,在精确的仿真模型基础上,进行了仿真分析,仿真结果表明,该方法有效、可靠。     

Design approaches and performance criteria for integrated voice/data switching

This paper examines some of the fundamental problems associated with the design and performance of integrated systems and networks that switch both voice and data. Specifically, the need for an integrated approach to the switching and transmission of voice and data is explored and alternative design considerations are discussed. One approach, described in detail, utilizes a distributed architecture to implement variable width channel allocations for the dynamic union of voice and data. Key performance criteria which aid the systems designer in evaluating the merits of a proposed unified design are identified. Examples are illustrated and supportive material is provided by a comprehensive bibliography.     

基于MP-WFRFT的多维联合调制卫星隐蔽通信研究

为进一步提高卫星信号的隐蔽性能,该文结合加权分数阶傅里叶变换(WFRFT)的星座混淆特性与混沌映射轨迹的抗截获特性,提出一种基于物理层安全的双极化卫星联合调制方案。借鉴“相位扰码”思想和“联合设计”理念,通过扩展4-WFRFT加权项参数,增加了卫星信号处理的多样性,在此基础上嵌入Logistic映射加密,提高了信息破解的难度。建立双极化卫星混沌安全传输系统模型,提出基于MP-WFRFT一体多维的组合隐蔽新概念,探索双极化卫星信号星座优化设计和裂变融合机理。仿真结果验证了所提方案的有效性。     

Teaching control system design through mechatronics: academic and industrial perspectives

The present approach to teaching control system design as a stand-alone course offered late in the undergraduate curriculum, with little discussion of hardware, implementation, or integration through design, is ineffective in preparing students for engineering practice. Control systems must be integrated into the design from the beginning and not be simply after-thought add-ons. Based on the authors' extensive experience teaching mechatronics to university students and professional engineers, an integrated mechatronic approach to teaching controls is proposed. This approach will seriously address the deficiencies in the present-day skills of working professionals, as observed by the authors in teaching professional engineering workshops. These deficiencies are a direct result of how we presently teach controls and related topics.     

局域跟踪的测速雷达网量测融合弹道解算

 组网测速雷达覆盖地域较广,火箭飞行初始段,只有局域雷达网捕获目标,没有足够速度量测,无法独立解算弹道.本文利用测速雷达精度较低的角度量测,以交会方法先获得初步的目标位置估计作为伪定位量测,利用无迹卡尔曼滤波(UKF)将其与高精度速度量测融合对弹道进行估计.蒙特卡罗仿真表明,该方法可以弥补角度量测的精度,获得满足精度要求的弹道估计.     

Development and hybrid force/position control of a compliant rescue manipulator

Performing search and rescue tasks in the ruins after disasters demand rescue robots with slender and compliant structure to accommodate the complicated configurations under debris. This paper presents the structural design and system composition of a novel tendon-sheath actuated compliant rescue manipulator with slender and flexible body. The proposed robot can drill into the narrow space where rescuers and traditional rigid robots cannot get in because of size limitation or toxic environment. The self-sensing calibration, dynamic modeling, and hybrid force/position control trajectory of the compliant gripper with integrated position and force monitoring capabilities are analyzed and discussed. With the aim of regulating the gripper displacement and clamping force during operation, a hybrid force/position control strategy is proposed based on a cascaded proportional-integral-derivative (PID) controller and a fuzzy sliding mode controller (FSMC). Experimental setups mainly consisting of servo motor, tendon sheath transmission components, compliant gripper, and real-time control system are established to calibrate the strain gauge sensors and identify the dynamic model parameters. Further experimental investigations involving force tracking experiments, position tracking experiments, and object grasping experiments are carried out. The experimental results demonstrate the effectiveness of the developed self-sensing approach and control strategies during rescue operation.     

传感器区域中基于网格的穿越轨迹算法研究

采用网格技术,并结合标签设定路由机制,提出一种搜索目标穿越轨迹的数值近似优化算法。该算法可使智能目标在起点至终点的轨迹长度不大于约束阈值的前提下实现近似最优穿越。分析和试验结果表明,算法能有效的搜索到满足约束条件的近似最佳轨迹,同时可以通过增加网格阶数来提高轨迹精确度。     

多小区协作无人机通信感知一体化系统的资源分配

在通信感知一体化系统中,由于通信与感知两者的目的并不完全一致,这使得通信和感知之间的性能折中问题尤为关键。本文研究多小区协作联网无人机网络的通信感知一体化问题,其中基站作为通信感知收发器与无人机用户通信,同时估计感知目标的位置。基于此,联合优化多个基站协作发射功率控制以及无人机用户的轨迹来平衡感知和通信性能,在满足无人机用户的信干噪比需求和感知目标定位的克拉美罗下界需求基础上,最小化基站的能量消耗。该问题是一个非凸优化问题,通常难以直接进行求解。为解决该问题,本文提出基于交替优化的联合基站功率控制与无人机轨迹优化方案,分别利用半正定松弛技术和连续凸近似技术对基站功率控制和无人机轨迹进行优化设计。最后,实验仿真结果验证了所提联合优化方案的性能。      

多功能综合射频系统的发展与关键技术

基于综合电子系统的演化过程,分析了发展多功能综合射频系统(MFIRFS)的必要性。在分析软件无线电技术的基础上,指出软件无线电技术是实现多功能综合射频系统的有效途径,并给出了多功能综合射频系统的设计框图。最后,讨论了为实现多功能综合射频系统必须首先研究的共用信号、共用孔径以及其它关键技术。     

Multihop data gathering in wireless sensor networks with a mobile sink

Network performance can be improved by using a mobile sink (MS) to collect sensed data in a wireless sensor network. In this paper, we design an efficient trajectory for MS, collecting data from sensor nodes in a multihop fashion, with the aim of prolonging the network lifetime. Considering event‐driven applications, we present an approach to jointly determine the optimal trajectory for MS and data paths and transmission rates from source nodes to MS, without considering any rendezvous points. In these applications, an MS is supposed to harvest the data from source nodes in a given time‐slot. We first show that this problem is in form of a mixed integer nonlinear programming model, which is NP‐hard. Then, to achieve an approximate solution, we divide the mentioned problem into 2 simple subproblems. In fact, after determining an approximate zone for the trajectory of MS, the optimal data paths and transmission rates from source nodes to the MS are obtained through a mathematical optimization model. Finally, to illustrate the efficiency of the proposed approach, we compare the performance of our algorithm to an rendezvous point–based and also the state‐of‐the‐art approach in different scenarios.     

A novel instantaneous power control strategy and analytic model forintegrated rectifier/inverter systems

This paper is concerned with the design and implementation of an integrated pulse width modulation (PWM) rectifier/inverter for three-phase induction motor drives. Two identical PWM converters are used to serve as power regulator with unity power factor and servo motor drive using field-oriented control, respectively. A new input-output instantaneous power balancing approach is proposed to improve the dynamic response of input power regulation during output load change in order to minimize the DC-link capacitance. By using the synchronous rotating-frame current regulators, both the input and output currents of the integrated system are characterized with fast current response and low harmonic distortion. The effects of the dynamic response using different input power control methods are compared and the systematic design and analysis of the proposed method are also presented. Theoretical results of the analysis are verified experimentally     

Design of 48 V Voltage regulator modules with a novel integrated magnetics

The push-pull forward topology with the current-doubler and synchronous rectifier is a suitable approach for high-input voltage regulator modules (VRMs) used to supply high-performance microprocessors. In order to improve efficiency and reduce size, this paper proposes an improved push-pull forward converter with a novel integrated magnetics. All the magnetic components including input filter inductor, step-down transformer and output filter inductors are integrated into a single EI or EE core. This topology is essentially the modified push-pull converter with the built-in input filter and the coupled-inductor current doubler rectifier. The proposed integrated magnetic structure features a simple core structure, a small leakage inductance and low winding and core losses. A design is given for a 48-V VRM with a 1.2-V and 70-A output, and its experimental results show that the proposed approach can offer a great improvement in efficiency.     

Simple-structure integrated coherent transceiver with novelcounter-receiving heterodyne detection scheme

A novel counter-receiving heterodyne detection (CRHD) scheme for a four-section integrated coherent transceiver for access networks is proposed. Error free detection at 100 Mbit/s is achieved with the CRHD scheme. This scheme leads to the relaxation of the design requirements of integrated coherent transceivers and facilitates duplex transmissions with coherent transceivers. A novel full-duplex transmission approach is also proposed and experimentally demonstrated     

An Integrated Framework for the Design and Optimization of SOC Test Solutions

We propose an integrated framework for the design of SOC test solutions, which includes a set of algorithms for early design space exploration as well as extensive optimization for the final solution. The framework deals with test scheduling, test access mechanism design, test sets selection, and test resource placement. Our approach minimizes the test application time and the cost of the test access mechanism while considering constraints on tests and power consumption. The main feature of our approach is that it provides an integrated design environment to treat several different tasks at the same time, which were traditionally dealt with as separate problems. We have made an implementation of the proposed heuristic used for the early design space exploration and an implementation based on Simulated Annealing for the extensive optimization. Experiments on several benchmarks and industrial designs show the usefulness and efficiency of our approach.     

Frequency-domain modeling of integrated electromagnetic power passives by a generalized two-conductor transmission structure

This work treats the modeling of integrated electromagnetic power passives for integrated power electronics modules by using a distributed conductive structure approach. The distributed L-C cell is chosen as the basis for modeling. This work presents the modeling of an L-C cell through the proposed generalized transmission structure theory that can be applied to both balanced and unbalanced current distributions. The load characteristics of a generalized transmission structure are investigated. The proposed theory has been extended to cascaded structures as well. The calculation results correlate well with the impedance measurement results. Some practical design issues are also discussed.     

A novel heuristic simulation‐optimization method for critical infrastructure in smart transportation systems

A simulation‐based optimization is a decision‐making tool that helps in identifying an optimal solution or a design for a system. An optimal solution and design are more meaningful if they enhance a smart system with sensing, computing, and monitoring capabilities with improved efficiency. In situations where testing the physical prototype is difficult, a computer‐based simulation and its optimization processes are helpful in providing low‐cost, speedy and lesser time‐ and resource‐consuming solutions. In this work, a comparative analysis of the proposed heuristic simulation‐optimization method for improving quality‐of‐service (QoS) is performed with generalized integrated optimization (a simulation approach based on genetic algorithms with evolutionary simulated annealing strategies having simplex search). In the proposed approach, feature‐based local (group) and global (network) formation processes are integrated with Internet of Things (IoT) based solutions for finding the optimum performance. Further, the simulated annealing method is applied for finding local and global optimum values supporting minimum traffic conditions. A small‐scale network of 50 to 100 nodes shows that genetic simulation optimization with multicriteria and multidimensional features performs better as compared to other simulation‐optimization approaches. Further, a minimum of 3.4% and a maximum of 16.2% improvement is observed in faster route identification for small‐scale IoT networks with simulation‐optimization constraints integrated model as compared to the traditional method. The proposed approach improves the critical infrastructure monitoring performance as compared to the generalized simulation‐optimization process in complex transportation scenarios with heavy traffic conditions. The communicational and computational‐cost complexities are least for the proposed approach.