期刊文献+
共找到360篇文章
< 1 2 18 >
每页显示 20 50 100
Adaptive fault-tolerant control of heavy lift launch vehicle via differential algebraic observer 被引量:2
1
作者 ZHAO Dang-jun JIANG Bing-yan 《Journal of Central South University》 SCIE EI CAS 2013年第8期2142-2150,共9页
A novel adaptive fault-tolerant control scheme in the differential algebraic framework was proposed for attitude control of a heavy lift launch vehicle (HLLV). By using purely mathematical transformations, the decou... A novel adaptive fault-tolerant control scheme in the differential algebraic framework was proposed for attitude control of a heavy lift launch vehicle (HLLV). By using purely mathematical transformations, the decoupled input-output representations of HLLV were derived, rendering three decoupled second-order systems, i.e., pitch, yaw and roll channels. Based on a new type of numerical differentiator, a differential algebraic observer (DAO) was proposed for estimating the system states and the generalized disturbances, including various disturbances and additive fault torques. Driven by DAOs, three improved proportional-integral- differential (PID) controllers with disturbance compensation were designed for pitch, yaw and roll control. All signals in the closed-loop system were guaranteed to be ultimately uniformly bounded by utilization of Lyapunov's indirect method. The convincing numerical simulations indicate that the proposed control scheme is successful in achieving high performance in the presence of parametric perturbations, external disturbances, noisy corruptions, and actuator faults. 展开更多
关键词 fault-tolerant control heavy lifting launch vehicle uniformly ultimately bounded attitude control differential algebra numerical differentiation
在线阅读 下载PDF
Feed-Forward-Like Decoupling Control in Coagulation Bath of Carbon Fiber Precursor
2
作者 徐峰 任立红 《Journal of Donghua University(English Edition)》 EI CAS 2014年第2期155-159,共5页
The coagulation bath system of carbon fiber precursor is a complicated and multivariable coupling system. Based on the model of industrial production,the full dynamic decoupling control of the coagulation bath system ... The coagulation bath system of carbon fiber precursor is a complicated and multivariable coupling system. Based on the model of industrial production,the full dynamic decoupling control of the coagulation bath system of carbon fiber precursor is achieved in combination with multivariable feed-forward-like decoupling and proportional-integral-differential( PID) control. Compared with the conventional PID decoupling control,the experiment results show that the proposed method has a better control effect. The use of the controller can achieve complete decoupling of three parameters from coagulation bath system. The method should have great applications. 展开更多
关键词 coagulation bath system feed-forward-like decoupling proponional-integral-differentialt PID) control multivariable coupling
在线阅读 下载PDF
Lax-Oleinik-Type Formulas and Efficient Algorithms for Certain High-Dimensional Optimal Control Problems
3
作者 Paula Chen Jerome Darbon Tingwei Meng 《Communications on Applied Mathematics and Computation》 EI 2024年第2期1428-1471,共44页
Two of the main challenges in optimal control are solving problems with state-dependent running costs and developing efficient numerical solvers that are computationally tractable in high dimensions.In this paper,we p... Two of the main challenges in optimal control are solving problems with state-dependent running costs and developing efficient numerical solvers that are computationally tractable in high dimensions.In this paper,we provide analytical solutions to certain optimal control problems whose running cost depends on the state variable and with constraints on the control.We also provide Lax-Oleinik-type representation formulas for the corresponding Hamilton-Jacobi partial differential equations with state-dependent Hamiltonians.Additionally,we present an efficient,grid-free numerical solver based on our representation formulas,which is shown to scale linearly with the state dimension,and thus,to overcome the curse of dimensionality.Using existing optimization methods and the min-plus technique,we extend our numerical solvers to address more general classes of convex and nonconvex initial costs.We demonstrate the capabilities of our numerical solvers using implementations on a central processing unit(CPU)and a field-programmable gate array(FPGA).In several cases,our FPGA implementation obtains over a 10 times speedup compared to the CPU,which demonstrates the promising performance boosts FPGAs can achieve.Our numerical results show that our solvers have the potential to serve as a building block for solving broader classes of high-dimensional optimal control problems in real-time. 展开更多
关键词 Optimal control Hamilton-Jacobi partial differential equations Grid-free numerical methods High dimensions Field-programmable gate arrays(FPGAs)
在线阅读 下载PDF
Nonlinear feedback synchronisation control between fractional-order and integer-order chaotic systems 被引量:7
4
作者 贾立新 戴浩 惠萌 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第11期194-199,共6页
This paper focuses on the synchronisation between fractional-order and integer-order chaotic systems. Based on Lyapunov stability theory and numerical differentiation, a nonlinear feedback controller is obtained to ac... This paper focuses on the synchronisation between fractional-order and integer-order chaotic systems. Based on Lyapunov stability theory and numerical differentiation, a nonlinear feedback controller is obtained to achieve the synchronisation between fractional-order and integer-order chaotic systems. Numerical simulation results are presented to illustrate the effectiveness of this method. 展开更多
关键词 chaos synchronisation fractional-order chaotic system nonlinear feedback control numerical differentiation
在线阅读 下载PDF
Local Bifurcation Analysis of a Delayed Fractional-order Dynamic Model of Dual Congestion Control Algorithms 被引量:6
5
作者 Min Xiao Guoping Jiang +1 位作者 Jinde Cao Weixing Zheng 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2017年第2期361-369,共9页
In this paper, we propose a delayed fractional-order congestion control model which is more accurate than the original integer-order model when depicting the dual congestion control algorithms. The presence of fractio... In this paper, we propose a delayed fractional-order congestion control model which is more accurate than the original integer-order model when depicting the dual congestion control algorithms. The presence of fractional orders requires the use of suitable criteria which usually make the analytical work so harder. Based on the stability theorems on delayed fractionalorder differential equations, we study the issue of the stability and bifurcations for such a model by choosing the communication delay as the bifurcation parameter. By analyzing the associated characteristic equation, some explicit conditions for the local stability of the equilibrium are given for the delayed fractionalorder model of congestion control algorithms. Moreover, the Hopf bifurcation conditions for general delayed fractional-order systems are proposed. The existence of Hopf bifurcations at the equilibrium is established. The critical values of the delay are identified, where the Hopf bifurcations occur and a family of oscillations bifurcate from the equilibrium. Same as the delay, the fractional order normally plays an important role in the dynamics of delayed fractional-order systems. It is found that the critical value of Hopf bifurcations is crucially dependent on the fractional order. Finally, numerical simulations are carried out to illustrate the main results. © 2017 Chinese Association of Automation. 展开更多
关键词 ALGEBRA Bifurcation (mathematics) Congestion control (communication) Convergence of numerical methods differential equations Stability
在线阅读 下载PDF
Medical Grabbing Servo System with Friction Compensation Based on the Differential Evolution Algorithm 被引量:4
6
作者 Yeming Zhang Kaimin Li +2 位作者 Meng Xu Junlei Liu Hongwei Yue 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2021年第6期316-330,共15页
This paper introduces a pneumatic finger cylinder servo control system for medical grabbing.First,according to the physical structure of the proportional directional valve and the pneumatic cylinder,the state equation... This paper introduces a pneumatic finger cylinder servo control system for medical grabbing.First,according to the physical structure of the proportional directional valve and the pneumatic cylinder,the state equation of the gas in the servo system was obtained.The Stribeck friction compensation model of a pneumatic finger cylinder controlled by a proportional valve was established and the experimental platform built.To allow the system output to bet-ter track the change in the input signal,the flow-gain compensation method was adopted.On this basis,a friction compensation control strategy based on a differential evolution algorithm was proposed and applied to the position control system of a pneumatic finger cylinder.Finally,the strategy was compared with the traditional proportional derivative(PD)strategy and that with friction compensation.The experimental results showed that the position accuracy of the finger cylinder position control system can be improved by using the friction compensation strategy based on the differential evolution algorithm to optimize the PD parameters. 展开更多
关键词 Position control Friction compensation differential evolution Parameter optimization
在线阅读 下载PDF
ADRC based control for a class of input time delay systems 被引量:6
7
作者 Dongyang Zhang Xiaolan Yao +1 位作者 Qinghe Wu Zhuoyue Song 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2017年第6期1210-1220,共11页
This paper is concerned with the control design and the theoretical analysis for a class of input time-delay systems with stable, critical stable or unstable poles. In order to overcome the time delay, a novel feed-fo... This paper is concerned with the control design and the theoretical analysis for a class of input time-delay systems with stable, critical stable or unstable poles. In order to overcome the time delay, a novel feed-forward compensation active disturbance rejection control(FFC-ADRC) approach is proposed. It combines advantages of the Smith predictor and the traditional active disturbance rejection control(ADRC). The tracking differentiator(TD) is designed to predict the control signal, which adds an anticipatory control to the control signal and allows a higher observer bandwidth to obtain better disturbance rejection. The modified extended state observer(ESO) is designed to estimate both system states and the total disturbances(internal disturbance, uncertainties and delayed disturbance). Then the Lyapunov theory and the theory of the input-output stability are applied to prove the asymptotic stability of the closed-loop control system. Finally, numerical simulations show the effectiveness and practicality of the proposed design. 展开更多
关键词 time-delay system feed-forward compensation active disturbance rejection control(FFC-ADRC) tracking differentiator(TD) Lyapunov theory bound-input-bound-output(BIBO) stability
在线阅读 下载PDF
A MAXIMUM PRINCIPLE APPROACH TO STOCHASTIC H_2/H_∞ CONTROL WITH RANDOM JUMPS
8
作者 张启侠 孙启良 《Acta Mathematica Scientia》 SCIE CSCD 2015年第2期348-358,共11页
A necessary maximum principle is given for nonzero-sum stochastic Oltterential games with random jumps. The result is applied to solve the H2/H∞ control problem of stochastic systems with random jumps. A necessary an... A necessary maximum principle is given for nonzero-sum stochastic Oltterential games with random jumps. The result is applied to solve the H2/H∞ control problem of stochastic systems with random jumps. A necessary and sufficient condition for the existence of a unique solution to the H2/H∞ control problem is derived. The resulting solution is given by the solution of an uncontrolled forward backward stochastic differential equation with random jumps. 展开更多
关键词 Nonzero-sum stochastic differential games maximum principle Poisson process stochastic H2/H∞ control forward backward stochastic differential equations
在线阅读 下载PDF
Some Equivalence Transform Methods for Simulating Models in Control Systems
9
作者 Degui, Liu 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 1993年第4期32-42,共11页
In this paper two classes of equivalence transform methods for solving ordinary differential equations are proposed. One class of method is the equivalence integral transform method for special differential algebraic ... In this paper two classes of equivalence transform methods for solving ordinary differential equations are proposed. One class of method is the equivalence integral transform method for special differential algebraic problems. The advantage of this class of method is such that the amount of work calculating one integration with parameters becomes that of two interpolations, when the system of nonlinear equations is solved on the right hand side function. The other class of method is the equivalence substitution method for avoiding calculating derivative on the right hand side function. In order to avoid calculation derivatives, two equivalence substitution methods are proposed here. The application instances of some special effect of the equivalence substitution methods are given. 展开更多
关键词 ALGEBRA Calculations Computer simulation control systems differential equations Integration Interpolation Mathematical models Mathematical transformations Nonlinear equations numerical methods
在线阅读 下载PDF
A Mixed Real-time Algorithm for the Forward Kinematics of Stewart Parallel Manipulator
10
作者 王孙安 万亚民 《Journal of Electronic Science and Technology of China》 2006年第2期173-180,共8页
Aimed at the real-time forward kinematics solving problem of Stewart parallel manipulator in the control course, a mixed algorithm combining immune evolutionary algorithm and numerical iterative scheme is proposed. Fi... Aimed at the real-time forward kinematics solving problem of Stewart parallel manipulator in the control course, a mixed algorithm combining immune evolutionary algorithm and numerical iterative scheme is proposed. Firstly taking advantage of simpleness of inverse kinematics, the forward kinematics is transformed to an optimal problem. Immune evolutionary algorithm is employed to find approximate solution of this optimal problem in manipulator's workspace. Then using above solution as iterative initialization, a speedy numerical iterative scheme is proposed to get more precise solution. In the manipulator running course, the iteration initialization can be selected as the last period position and orientation. Because the initialization is closed to correct solution, solving precision is high and speed is rapid enough to satisfy real-time requirement. This mixed forward kinematics algorithm is applied to real Stewart parallel manipulator in the real-time control course. The examination result shows that the algorithm is very efficient and practical. 展开更多
关键词 stewart parallel manipulator forward kinematics immune evolutionary algorithm numerical iterative scheme real-time control
在线阅读 下载PDF
一种新型3-RRPU并联机构的运动学及鲁棒控制研究
11
作者 韩秀英 李旭莹 +1 位作者 凌金博 杨琨 《机电工程》 CAS 北大核心 2024年第8期1464-1471,共8页
针对现有的三平移并联机构大多正解不唯一、较难实现精确稳定运动控制的问题,提出了一种新的3-RRPU型三平移并联机构,同时研究了机构的运动学、动力学及轨迹跟踪控制方法。首先,运用螺旋理论分析了该机构三平移的原理,进行了驱动输入的... 针对现有的三平移并联机构大多正解不唯一、较难实现精确稳定运动控制的问题,提出了一种新的3-RRPU型三平移并联机构,同时研究了机构的运动学、动力学及轨迹跟踪控制方法。首先,运用螺旋理论分析了该机构三平移的原理,进行了驱动输入的选取与论证,对机构平台奇异性、驱动奇异性和支链奇异性进行了分析;其次,运用运动学理论建立了运动学模型,推导了位置正、逆解析解;再次,运用拉格朗日动力学理论建立了机构操作空间的刚体动力学模型;最后,提出了一种基于非线性反馈解耦的自适应滑模轨迹跟踪控制方法,以证明其控制稳定性,并基于动力学模型对空间轨迹跟踪精度和控制力矩进行了仿真分析。研究结果表明:3-RRPU并联机构的位置正解在一般位形下具有唯一性,机构的平台奇异位形和驱动奇异位形少且无支链奇异。该轨迹控制方法可使机构在载荷20 kg、速度0.18 m/s、加速度0.12 m/s 2下,实现0.002 m以内的高精度复杂轨迹跟踪;基于Sigmoid函数的轨迹控制方法还能有效削弱控制力矩的抖振,为实现工业领域高速、高精度、高性能的三平移运动提供了新方法。 展开更多
关键词 三平移并联机构 位置正解 奇异性 螺旋理论 非线性反馈解耦 自适应滑模轨迹跟踪控制方法 机构操作空间
在线阅读 下载PDF
IF-ZVVCD与SMO的PMSM无位置传感器全速域复合控制
12
作者 毛天龙 李萍 +1 位作者 赵峰 刘国忠 《机床与液压》 北大核心 2024年第16期40-48,54,共10页
针对永磁同步电机(PMSM)全速域无位置传感器控制中,零低速阶段的高频注入法会引起转矩脉动、噪声等问题,提出一种IF控制结合零电压矢量电流微分法(ZVVCD)实现电机零低速运行,并与改进滑模观测器法复合达到全速域无位置传感器控制目标。... 针对永磁同步电机(PMSM)全速域无位置传感器控制中,零低速阶段的高频注入法会引起转矩脉动、噪声等问题,提出一种IF控制结合零电压矢量电流微分法(ZVVCD)实现电机零低速运行,并与改进滑模观测器法复合达到全速域无位置传感器控制目标。在零低速阶段,IF控制法启动电机并在低速切换为ZVVCD,减小转速波动,提高控制精度;在中高速阶段,利用连续光滑的Sigmoid函数及扩展卡尔曼滤波器改进滑模观测器,减少系统抖振,提高转速稳定性;在转速过渡阶段,设计斜率可调的加权切换函数实现零低速与中高速控制方法的平滑切换。实验结果表明:所提复合控制策略能够实现PMSM全速域无位置传感器控制,消除转矩脉动,转子转速与位置信息辨识准确,系统动态响应快、稳态性能好。 展开更多
关键词 永磁同步电机 IF控制 零电压矢量电流微分法 改进滑模观测器法 无位置传感器复合控制
在线阅读 下载PDF
大断面大压差远程控制平衡风门技术研究 被引量:3
13
作者 段思恭 彭然 +1 位作者 李伟 张浪 《中国矿业》 北大核心 2024年第5期127-135,共9页
随着煤矿开采逐渐向深部延伸,平衡风门作为重要的通风设施在井下的应用越来越广泛。然而,当大断面风门两侧存在较大压差时,会导致一系列问题,容易使风门受到破坏。为解决这一问题,对平衡风门进行了重新设计,增加了抗变形、三维可调节、... 随着煤矿开采逐渐向深部延伸,平衡风门作为重要的通风设施在井下的应用越来越广泛。然而,当大断面风门两侧存在较大压差时,会导致一系列问题,容易使风门受到破坏。为解决这一问题,对平衡风门进行了重新设计,增加了抗变形、三维可调节、就地智能控制和远程解锁短路排烟等功能。研究结果显示,在外形尺寸不变的情况下,新设计的风门自重减轻了约50%,但其强度得到增强,能够适应巷道变形量达到200mm。通过有限元分析对门扇、门框、迎风面等三个部件进行数值模拟计算,发现在16000N载荷下,门扇出现了局部失效,且最大位移发生在距离合页轴最远端的门扇受载荷面上。当巷道四周受到压力使门框产生最大变形量达到200mm后,风门仍能继续承受3000N的压力,未出现失效情况。当井下风压达到1000Pa时,最大位移出现在左门扇受载荷面的右下角位置,出现了局部失效,但并不影响风门的使用。经现场试验验证,平衡风门在一定矿压和大风压的情况下,正常使用且满足调风需求。研究结果表明,这种具备远程自动控制功能的大断面大压差的新型平衡风门能够提高风门的稳定性,确保通风系统的高效稳定运行。 展开更多
关键词 大断面大压差巷道 巷道变形 矿井通风 远程控制 数值模拟
在线阅读 下载PDF
对接机构动力学建模与电子差动捕获缓冲研究
14
作者 张冰肖 王博洋 +2 位作者 刘铸永 刘璟龙 时军委 《宇航学报》 CSCD 北大核心 2024年第12期1910-1921,共12页
针对空间对接机构智能化和轻量化的需求,借鉴机械式对接机构差动缓冲的思想,提出一种电子差动式捕获缓冲控制算法。首先根据单向递推组集方法,考虑对接机构间接触碰撞,建立了对接机构捕获缓冲过程的多体动力学模型。其次采用3组参数分别... 针对空间对接机构智能化和轻量化的需求,借鉴机械式对接机构差动缓冲的思想,提出一种电子差动式捕获缓冲控制算法。首先根据单向递推组集方法,考虑对接机构间接触碰撞,建立了对接机构捕获缓冲过程的多体动力学模型。其次采用3组参数分别对6个直线驱动机构的位移进行控制,调节对接环的纵向、横向滚转、偏航俯仰3类捕获缓冲性能,实现了3类对接性能的解耦控制。对主动控制式对接机构的捕获缓冲过程进行动力学-控制仿真,仿真结果表明该控制算法能很好地完成对接任务,并具有不同方向捕获缓冲性能解耦、对系统频响要求低等优良特性,为新一代对接机构的控制设计提供理论基础和技术支撑。 展开更多
关键词 对接机构 多体动力学 递推组集方法 接触碰撞 差动式控制
在线阅读 下载PDF
低成本惯性多冗余导航控制一体机设计
15
作者 牛志朝 任磊 +1 位作者 贺韬 崔孟楠 《电子技术应用》 2024年第2期102-106,共5页
为了智能体的精确定位和定姿,实现其稳定运动控制,设计了一种低成本多惯性冗余导航控制一体机,给出了设计方法。稳压电路的开关电源MP2482DN和线性电源JW29300U-3.3V为一体机提供稳定5 V和3.3 V的较大功率电源;控制器STM32H7的SPI采用... 为了智能体的精确定位和定姿,实现其稳定运动控制,设计了一种低成本多惯性冗余导航控制一体机,给出了设计方法。稳压电路的开关电源MP2482DN和线性电源JW29300U-3.3V为一体机提供稳定5 V和3.3 V的较大功率电源;控制器STM32H7的SPI采用星形拓扑总线与3片六轴惯性芯片BMI088通信,2路TTL串口与差分卫星定位板双向通信,实现智能体定位和定姿;控制器STM32F4的CAN总线接口与智能体底盘双向通信,实现其运动控制,1路TTL串口实现与控制器STM32H7的双向通信;两控制器的网络接口与上位机组成无线局域网,实现数据交换和状态监控。整个系统具有功耗低、体积小、成本低、接口丰富的特点。 展开更多
关键词 惯性多冗余 定位和定姿 导航控制一体 低成本
在线阅读 下载PDF
锚点位置对大跨度斜拉桥成桥线形的影响
16
作者 邢龙飞 苑仁安 韩若愚 《铁道建筑》 北大核心 2024年第11期63-67,共5页
为研究大跨度斜拉桥由名义锚点转化为实际锚点位置时的线形变化,首先从力的三要素出发,分析斜拉索设计过程中由于锚点位置转变导致桥梁线形偏差的原因,然后结合工程算例对不同试验工况下锚点位置转变引起的线形偏差进行计算分析。结果表... 为研究大跨度斜拉桥由名义锚点转化为实际锚点位置时的线形变化,首先从力的三要素出发,分析斜拉索设计过程中由于锚点位置转变导致桥梁线形偏差的原因,然后结合工程算例对不同试验工况下锚点位置转变引起的线形偏差进行计算分析。结果表明:在斜拉索设计时须充分考虑梁端锚点预偏与锚垫板厚度对斜拉索实际锚点和下料长度的影响,否则斜拉索可能会出现设计不合理的问题,导致实际锚点位置的成桥线形发生较大偏差。 展开更多
关键词 斜拉桥 锚点位置 数值模拟 斜拉索设计 成桥线形 施工控制
在线阅读 下载PDF
基于电磁式惯性作动器的四面固支板前馈补偿线性自抗扰振动主动控制 被引量:1
17
作者 纪中琦 李生权 +2 位作者 李娟 张禄进 童忻炜 《陕西科技大学学报》 北大核心 2024年第4期160-166,共7页
针对基于电磁式惯性作动器的四面固支板振动系统中存在的由相位滞后、功率放大器等模拟器件、数据采集卡的采样时间等因素导致的时间延迟,本文提出了一种基于跟踪微分器(Tracking Differentiator, TD)的前馈补偿自抗扰控制方法.首先,利... 针对基于电磁式惯性作动器的四面固支板振动系统中存在的由相位滞后、功率放大器等模拟器件、数据采集卡的采样时间等因素导致的时间延迟,本文提出了一种基于跟踪微分器(Tracking Differentiator, TD)的前馈补偿自抗扰控制方法.首先,利用振动理论和电磁感应原理,建立了基于惯性作动器四面固支板的振动模型;其次,利用跟踪微分器获得输入信号的跟踪信号及其微分信号,以实现相位超前功能,并根据控制信号与系统输出同步的原则设计了扩张状态观测器(Extended State Observer, ESO)来估计系统状态和总干扰.最后,搭建了一套基于NI PCIe采集系统的振动控制平台,验证所提出的振动主动控制策略的控制性能.开展了传统三阶-线性自抗扰控制、预测估计器的线性自抗扰控制和所提的振动控制策略的对比试验,结果表明了所提的基于TD的前馈补偿自抗扰控制器具有最佳的抗扰和振动抑制性能. 展开更多
关键词 电磁式惯性作动器 四面固支板 跟踪微分器 扩张状态观测器 前馈补偿自抗扰控制
在线阅读 下载PDF
Linear Quadratic Optimal Control for Systems Governed by First-Order Hyperbolic Partial Differential Equations
18
作者 XUE Xiaomin XU Juanjuan ZHANG Huanshui 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2024年第1期230-252,共23页
This paper focuses on linear-quadratic(LQ)optimal control for a class of systems governed by first-order hyperbolic partial differential equations(PDEs).Different from most of the previous works,an approach of discret... This paper focuses on linear-quadratic(LQ)optimal control for a class of systems governed by first-order hyperbolic partial differential equations(PDEs).Different from most of the previous works,an approach of discretization-then-continuousization is proposed in this paper to cope with the infinite-dimensional nature of PDE systems.The contributions of this paper consist of the following aspects:(1)The differential Riccati equations and the solvability condition of the LQ optimal control problems are obtained via the discretization-then-continuousization method.(2)A numerical calculation way of the differential Riccati equations and a practical design way of the optimal controller are proposed.Meanwhile,the relationship between the optimal costate and the optimal state is established by solving a set of forward and backward partial difference equations(FBPDEs).(3)The correctness of the method used in this paper is verified by a complementary continuous method and the comparative analysis with the existing operator results is presented.It is shown that the proposed results not only contain the classic results of the standard LQ control problem of systems governed by ordinary differential equations as a special case,but also support the existing operator results and give a more convenient form of computation. 展开更多
关键词 Discretization-then-continuousization method first-order hyperbolic partial differential equations forward and backward partial difference equations linear quadratic optimal control.
原文传递
基于差分无人机的三维建模及精度分析
19
作者 黄越鹏 李燕婷 +1 位作者 宁黎平 张江华 《青海科技》 2024年第5期77-86,共10页
近年来,随着无人机技术愈发成熟,基于无人机的倾斜摄影测量技术在构建数字城市、数字校园、数字园区等数字化三维地图中得到广泛应用。该研究采用具备RTK实时差分定位技术的四旋翼无人机,搭载D-OP3000高精度五镜头相机,对某大学校园进... 近年来,随着无人机技术愈发成熟,基于无人机的倾斜摄影测量技术在构建数字城市、数字校园、数字园区等数字化三维地图中得到广泛应用。该研究采用具备RTK实时差分定位技术的四旋翼无人机,搭载D-OP3000高精度五镜头相机,对某大学校园进行倾斜影像数据采集;利用RTK-GNSS静态控制测量技术在研究区内采集检查点及像控点的坐标数据。通过Smart3D建模软件进行免像控点和加入像控点两次独立的实景三维建模,并基于检查点数据进行精度分析,其中免像控点模型的3D平面与高程中误差分别为0.0645 m和0.0856 m,加入像控点的模型3D平面与高程中误差分别为0.0630 m和0.0751 m。研究表明,在免像控的条件下,模型依然具有较高的精度水平,并且可以大幅度节约人工和时间成本。 展开更多
关键词 倾斜摄影测量 免像控实景三维 实时差分定位 精度对比分析
在线阅读 下载PDF
高速公路软土路基路桥过渡段差异沉降研究 被引量:2
20
作者 王刚 《山东交通科技》 2024年第1期14-17,共4页
以山东省某高速公路软土路基路桥过渡段为研究对象,基于Midas有限元软件,分析软基路桥过渡段处治前后沉降量变化规律,并研究回填材料、高压旋喷桩对软基路桥过渡段沉降控制效果,探讨高压旋喷桩的位置参数、尺寸参数对沉降量的影响。不... 以山东省某高速公路软土路基路桥过渡段为研究对象,基于Midas有限元软件,分析软基路桥过渡段处治前后沉降量变化规律,并研究回填材料、高压旋喷桩对软基路桥过渡段沉降控制效果,探讨高压旋喷桩的位置参数、尺寸参数对沉降量的影响。不进行处治时,填料区的沉降变形曲线呈“V”形,沉降量先增大后减小,距桥台台背4.5 m时,沉降量达到最大值0.11 m;随距路基中心线距离的增大,路基表面沉降量在不断减小。换填法使得填料区的最大沉降量距桥台台背距离在逐渐变大,换填效果随刚度的增加在逐渐减弱,且当填料刚度增大5倍时,填料区的沉降量普遍小于软土区沉降量。喷射注浆法的沉降控制效果较稳定,沉降量随桩长的增大不断减小,当桩间距从1 m增加到1.5 m时,5 m桩长填料区最大沉降量增大了25%。 展开更多
关键词 路桥过渡段 数值模拟 软土路基 差异沉降 沉降控制措施
在线阅读 下载PDF
上一页 1 2 18 下一页 到第
使用帮助 返回顶部