共查询到20条相似文献,搜索用时 609 毫秒
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应变式称重传感器的非线性校正 总被引:1,自引:0,他引:1
因受自身材质、工艺的限制以及外界环境影响,应变式称重传感器输入—输出特性存在非线性误差,影响系统测量精度,需要对其进行非线性校正。采用曲线拟合法建立传感器逆模型,并存储于单片机中用于非线性校正,结合外围硬件电路完成对被测数据的采集与实时处理。设计完成的测量系统具有一定的环境自适应性和智能化特点。实验结果表明,校正后系统的非线性和零点漂移得到明显改善,同时软、硬件相结合的设计方式具有较高的应用价值。 相似文献
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基于二元多项式拟合法的压力传感器输入信号重构 总被引:1,自引:1,他引:0
为了同时解决压力传感器输出特性的非线性和温度漂移问题,提出利用二元多项式根据传感器输出信号及其内部温度来重构被测压力.给出了被测压力重构模型的具体形式,以传感器静态特性标定试验数据为依据,利用最小二乘法求解模型系数矩阵,利用单点最大拟合误差、误差平方和模型阶次三项指标进行模型择优.基于重构模型给出了测量电路检测精度估算方法.本方法在传感器静态特性标定数据范围内得到了便于工程计算的一致表达式,同时解决了传感器的非线性和温度漂移两个主要问题,计算所用数据量大大小于插值法.某型硅谐振压力传感器的应用验证了本方法的合理性和有效性. 相似文献
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针对低轨道运行的编队卫星在非线性项作用下,伴随卫星运行的相对运动轨道发生偏移的情况,传统的李亚普诺夫方法能较好地控制轨道的初始偏移,使系统达到李亚普诺夫大范围一致稳定,但长期项误差震荡较大.本文提出了一种多回路结构的卫星轨道保持的控制方法,内回路选取使系统满足李亚普诺夫大范围一致稳定的控制律,外回路选取LQR线性状态调节器.此内外回路调节器能更好地抑制环绕卫星相对于基准轨道的误差漂移,更好地稳定编队队形.最后,数值仿真结果验证了此方法比传统的李亚普诺夫方法具有使编队更稳定的效果. 相似文献
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在污水生化处理过程中,存在着多变量耦合、强非线性、参数时变、大滞后等特点,面对这些特点,传感器故障频发,从而导致生化过程无法得到有效优化和诊断.为此,本文在结合动态数据特性的基础上提出了一种基于变分贝叶斯混合因子的动态故障诊断方法,同时,利用混合因子的在线调整实现了诊断模型的半自适应化.该方法能够捕捉到污水处理过程的强非线性和动态性,从而可有效降低故障诊断的误报率和漏报率.通过在国际水协会的BSM1模型上的模拟研究,充分表明所提出的策略可以显著提高故障诊断能力,精确地检测传感器的突变和漂移故障,甚至定位故障所发生的根本原因. 相似文献
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S. O. Degertekin 《Structural and Multidisciplinary Optimization》2007,34(4):347-359
In this article, two algorithms are presented for the optimum design of geometrically nonlinear steel space frames that are
based on simulated annealing and genetic algorithm. The design algorithms obtain minimum weight frames by selecting suitable
sections from a standard set of steel sections such as the American Institute of Steel Construction (AISC) wide-flange shapes.
Stress constraints of AISC Load and Resistance Factor Design (LRFD) and AISC Allowable Stress Design (ASD) specifications,
maximum (lateral displacement) and interstorey drift constraints, and also size constraints for columns were imposed on frames.
The algorithms were applied to the optimum design of three space frame structures, which have a very small amount of nonlinearity.
The unconstrained form of objective function was applied in both optimum design algorithms, and constant penalty factors were
used instead of gradually increasing ones. Although genetic algorithm took much less time to converge, the comparisons showed
that the simulated annealing algorithm yielded better designs together with AISC-LRFD code specification. 相似文献
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高精度压力传感器是航空领域应用非常广泛的传感器,常处于严苛的工作环境.为使压力传感器在特殊的测试环境中保持高测量精度,传感器的性能设计成为研究关键.合理的信号调理电路以及正确的误差校准原理,将显著提高传感器性能.通过在传感器的信号调理电路中使用可编程模拟信号调节器,对桥式压力敏感元件的温度漂移误差及非线性误差进行实时修正,使压力传感器实现了智能化自校准,有效提升了压力传感器的精度和环境适应性. 相似文献
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漂移管是离子迁移谱(IMS)检测仪的核心部件,设计优劣直接影响IMS仪器的性能。离子在漂移管中的运动十分复杂,受电场及气流、温湿度、压强等多种环境因素的影响。为了研究离子在漂移管中的迁移过程,为IMS漂移管的设计和优化提供指导,本文建立了一种基于SIMION/SDS的多物理场仿真方法,综合考虑了电场、气流、温度及压强等因素的影响,模拟离子在漂移管中的运动。选择IMS标准剂进行实验测试,将仿真结果与实测的离子迁移谱图进行对比分析,验证该仿真方法的正确性。结果表明,漂移管的多物理场仿真方法能够有效地模拟多环境因素影响下离子在漂移管中的迁移情况,对漂移管的设计优化有着重要的意义。 相似文献
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针对重现概念漂移检测中的概念表征和分类器选择问题,提出了一种适用于含重现概念漂移的数据流分类的算法——基于主要特征抽取的概念聚类和预测算法(Conceptual clustering and prediction through main feature extraction, MFCCP)。MFCCP通过计算不同批次样本的主要特征及影响因子的差异度以识别重复出现的概念,为每个概念维持且及时更新一个分类器,并依据Hoeffding不等式选择最合适的分类器对当前样本集实施分类,以
提高对概念漂移的反应能力。在3个数据集上的实验表明:MFCCP在含重现概念漂移的数据集上的分类准确率,对概念漂移的反应能力及对概念漂移检测的准确率均明显优于其他4种
对比算法,且MFCCP也适用于对不含重现概念漂移的数据流进行分类。 相似文献
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高精度传感器弹性元件应变梯度的非线性误差分析 总被引:1,自引:0,他引:1
定量地分析了弹性元件应变梯度产生的非线性误差,通过分析计算表明弹性元件粘贴区的应变梯度是应变式高精度传感器非线性误差产生的主要因素之一。 相似文献
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Decentralized intelligent tracking control for uncertain high‐order stochastic nonlinear strong interconnected systems in drift and diffusion terms
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Wen‐Jie Si 《国际强度与非线性控制杂志
》2018,28(7):2780-2805
》2018,28(7):2780-2805
This paper focuses mainly on decentralized intelligent tracking control for a class of high‐order stochastic nonlinear systems with unknown strong interconnected nonlinearity in the drift and diffusion terms. For the control of uncertain high‐order nonlinear systems, the approximation capability of RBF neural networks is utilized to deal with the difficulties caused by completely unknown system dynamics and stochastic disturbances, and only one adaptive parameter is constructed to overcome the overparameterization problem. Then, to address the problem from high‐order strong interconnected nonlinearities in the drift and diffusion terms with full states of the overall system, by using the monotonically increasing property of the bounding functions, the variable separation technique is achieved. Lastly, based on the Lyapunov stability theory, a decentralized adaptive neural control method is proposed to reduce the number of online adaptive learning parameters. It is shown that, for bounded initial conditions, the designed controller can ensure the semiglobally uniformly ultimate boundedness of the solution of the closed‐loop system and make the tracking errors eventually converge to a small neighborhood around the origin. Two simulation examples including a practical example are used to further illustrate the effectiveness of the design method. 相似文献
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为提高对海上遇险目标的搜索效率,在搜救行动开始前需要对搜索目标的位置进行预测.在获得遇险目标的最后告知位置后,计算漂流轨迹可以预测搜救力量展开搜索时险目标的实际位置.通过计算各环境因素带来的漂移速度分量,进行矢量合成后可以得到遇险目标的漂移速度.对搜索目标遇险后的漂移轨迹进行预测,以此划定搜索区域. 相似文献
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传统模拟积分器由于运放和积分电容的不理想,存在着零点漂移、非线性误差以及泄漏等问题。而当积分时间不断增加时,积分漂移随之线性增加,并成为影响积分输出精度的重要因素之一。对此设计了自适应智能型积分器。主要思想:利用积分器前一次的漂移斜率来扣除本次的积分值,以达到减小漂移的目的。 相似文献
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Mean-square performance bounds are derived for smoothing and prediction problems associated with the broad class of nonlinear dynamic systems which, when modeled by Ito differential equations, contain drift (·dt) coefficients which are, to within a uniformly Lipschitz residual, jointly linear in the system state and externally applied control. Included in this paper are lower bounds on the error covariance attainable by any smoother or any predictor, including the optimum, and upper bounds on the performance of some simple, implementable predictors reminiscent of the designs which are optimal in the linear case. The lower bounds on smoothing and prediction performance are established using measure-transformation techniques to relate a version of the nonlinear problem to its linearization. The upper bound on prediction performance is constructed by a direct analysis of the estimation error. All the bounds hold for correlated system and observation noises. All are rigorously derived and independent of control or control law. In each case, the computational effort is comparable to that for the corresponding optimum linear smoothing or prediction problem. The bounds converge with vanishing nonlinearity (vanishing Lipschitz constants) to the known optimum performance for the limiting linear system. Consequently, the bounds are asymptotically tight and the simple designs studied are asymptotically optimal with vanishing nonlinearity. 相似文献
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Adaptive stabilization of uncertain nonholonomic systems by state and output feedback 总被引:3,自引:0,他引:3
In this paper, adaptive state feedback and output feedback control strategies are presented for a class of nonholonomic systems in chained form with drift nonlinearity and parametric uncertainties. Both control laws are developed using state scaling and backstepping techniques. In particular, novel adaptive switching is proposed to overcome the uncontrollablity problem associated with x0(t0)=0. Observer-based output feedback design is developed when only partial system states are measurable, and a filtered observer rather than the traditional linear observer is used to handle the technical problem due to the presence of unavailable states in the regressor matrix. The proposed control strategies can steer the system globally converge to the origin, while the estimated parameters maintain bounded. 相似文献