共查询到20条相似文献,搜索用时 15 毫秒
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V. B. Larin 《International Applied Mechanics》2005,41(4):441-448
A nonholonomic model of a wheeled robot with one steering wheel is considered. The model accounts for dynamic effects. The motion-planning problem for this model is solved by reducing it to a linear two-point boundary-value problem__________Translated from Prikladnaya Mekhanika, Vol. 41, No. 4, pp. 117–125, April 2005. 相似文献
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《基于设计的结构力学与机械力学》2013,41(3):413-432
Abstract The article deals with the design and properties of generalized predictive control (GPC) for path control of redundant parallel robots. Redundant parallel classification means redundant number of actuators, i.e., more actuators than degrees of freedom of the robot. Control of such structures suffers from several new control problems like potential inconsistency of steady state positions or nonuniqueness of control actions. The article explains classical direct derivation of GPC and its modification based on square root two-step design of control actions for solving the control problems. As an example for verification of algorithms, a prototype of a planar redundant parallel robot is used. Both design approaches are compared and several possibilities of extensions are presented for taking into consideration additional requirements, like smooth course of actuators or fulfillment of the anti-backlash condition. 相似文献
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K. KOJIMA T. KODAMA N. KANEKO M. KAWAHARA 《International Journal of Computational Fluid Dynamics》2013,27(1-2):193-200
A numerical thermal management system for the ground structure is presented. The system consists of two parts, i.e. the identification analysis of thermal conductivity and the thermal control analysis for the ground. The former is carried out by using the nonlinear least squares method and the latter is based on the optimal control theory. The formulations of these methods are presented and they are applied to an actual putting green in a golf course. Reasonable thermal conductivity of the ground is identified by parameter estimation and the ground temperature is theoretically controlled as illustrated by numerical examples. 相似文献
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机敏柔性梁的振动主动控制 总被引:1,自引:0,他引:1
提出了用于机敏结构中振动主动控制的仿人控制算法,对压电阻尼技术进行了理论和实验研究,给出了传感器,执行器和受控结构之间的关系,用PZT作执行元件实现了柔性梁振动主动控制系统,给出了实验结果。 相似文献
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William Prager 《基于设计的结构力学与机械力学》2013,41(1):71-90
ABSTRACT Examples are presented to show that optimal designs may have unexpected properties that require particularly careful formulation of problems of structural optimization. 相似文献
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模型不确定压电柔性结构的多目标振动控制 总被引:1,自引:0,他引:1
以压电柔性结构为对象,考虑其被控模态参数的不确定性和因剔除残余模态所引起的动态不确定性,建立了结构的不确定线性分式模型;根据不确定模型设计了一个对结构进行振动控制的动态输出反馈控制器,使闭环系统满足鲁棒稳定、扰动抑制、极点配置约束及控制输入约束等性能要求;并利用线性矩阵不等式,将具有多个性能要求的振动控制问题转化为具有线性矩阵不等式约束和线性目标函数的凸优化问题。最后以简支压电柔性梁为例,设计了一个融合多性能指标的动态输出反馈非同位控制器,并给出了仿真结果。 相似文献
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Joint Stiffness Control of a Two-Link Flexible Arm 总被引:1,自引:0,他引:1
In this study, results are presented for the control of impactinduced transient oscillations on a two-link flexible arm by varying thestiffness of an elbow actuator. Case studies were conducted to determinethe effectiveness of the control method as various arm parameters suchas payload, length, elbow angle, and elbow stiffness changed. Theresults of selected cases were then verified experimentally anddemonstrated that the suggested controller was effective, robust, andquite insensitive to parameter variations. 相似文献
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斜拉索附加带刚度阻尼器的参数优化分析 总被引:1,自引:0,他引:1
斜拉索的风雨振动及其控制是目前国内外研究的热点问题之一.其中,阻尼器减振技术得到了广泛的应用,但是,对于阻尼器的一些非理想因素如阻尼器刚度的影响,尚缺乏研究.本文对斜拉索附加带刚度的阻尼器的模态阻尼比进行了分析,通过分析复频率的变化,在阻尼器安装点距拉索锚固点长度与拉索长度之比远远小于1的假设下,得到了考虑刚度影响的拉索阻尼器的模态阻尼比的近似解析解.该近似解析解与数值计算得到的精确解对比吻合良好.对于斜拉索减振,与忽略刚度影响的阻尼器类似,带刚度的阻尼器同样存在着通用设计优化曲线.阻尼器所带有的刚度将显著的减小拉索-阻尼器系统所能获得的最大模态阻尼比,而所对应的阻尼器最优阻尼值将增大. 相似文献
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采用最优跟踪控制方法对柔性机械臂线性化主动控制中的时滞问题进行研究。首先采用一种积分变换,将包含时滞项的动力学方程转换成形式上不包含时滞项的标准形式,然后根据最优跟踪控制理论设计控制律。在每一步控制律的计算中,不但包含有当前步的状态反馈,而且包含有前若干步控制的线性组合。文中还给出了一个模态坐标的提取方法。仿真结果显示,若对时滞不处理,控制系统会在很小时滞量时出现发散;当控制系统中的时滞量不大时,本文的线性化时滞控制设计能够取得较好的控制效果;当系统存在较大时滞量时,线性化时滞控制设计的有效范围是有限的。 相似文献
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Modern space vehicles structure requisites are getting more and more stringent and complex as mission tasks become more sophisticated. This leads to the necessity of developing analysis methods that take into account structure flexibility and the need of reducing manoeuvre time as much as possible. In this work, a method based on the Hamilton Principle in its weak mixed form is developed, in which co-ordinates derivatives do not appear, but only their virtual variations. The proposed formulation is able to take into account system flexibility and saturation constraints on control torques and forces. A non-linear variational condition is obtained, which can be solved by means of a time-finite-element technique to give the minimum-time solutions of the control problem. The solutions for slewing manoeuvres are given, along with a new solution of the distributed optimal control problem. 相似文献
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Multicriterion structural optimization problems stated as minimization of the maximum of a set of weighted criteria are considered. Interpretation of the min-max problem as a simple minimization problem for an upper bound on the criteria leads to a formulation that is convenient for analysis of problems with global as well as local objectives. The method is demonstrated on multipurpose design of a vibrating cantilever, on design of a 相似文献
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A nonlinear adaptive vibration absorber to control the vibrations offlexible structures is investigated. The absorber is based on thesaturation phenomenon associated with dynamical systems possessingquadratic nonlinearities and a two-to-one internal resonance. Thetechnique is implemented by coupling a second-order controller with thestructure through a sensor and an actuator. Energy is exchanged betweenthe structure and the controller and, near resonance, the structure'sresponse saturates to a small value.Experimental results are presented for the control of a rectangularplate and a cantilever beam using piezoelectric ceramics andmagnetostrictive alloys as actuators. The control technique isimplemented using a digital signal processing board and a modelingsoftware. The control strategy is made adaptive by incorporating anefficient frequency-measurement technique. This is validated bysuccessfully testing the control strategy for a nonconventionalproblem, where nonlinear effects hinder the application of thenonadaptive controller. 相似文献