基于有限字长考虑的采样系统最优控制器实现

提出了有限字长约束下采样控制器最优实现的新的有效算法：将最优实现问题演化为非线性规划问题,从而可以利用现有的优化技术来求解。理论推导和数值实例表明：该算法计算简便,所得的最优实现结果较已有研究结果有更大的稳定界和更短的稳定字长。     

有限字长数字控制器的一种极点灵敏度优化结构

研究了有限字长数字控制器的一种最优实现,主要考虑了系统的主导极点相对于控制器实现的灵敏度。通过定义该灵敏度,并分析它与实现所在坐标系的关系,得到了最小化该测度的一类结构。     

设计有限字长FIR数字滤波器的蚂蚁算法

蚂蚁算法(AA)是一种模拟蚂蚁觅食时建立蚁巢到食物最短路径的新型启发式优化算法.本文通过改进蚂蚁算法,取消了蚂蚁算法原型的禁忌表,将其应用于有限字长FIR数字滤波器的优化设计,并在最小最大(MM)、最小平方(LS)和纹波约束最小平方(PCLS)优化准则下,在通带和阻带施加适当的约束条件,建立相应的优化模型,给出了设计的详细实现步骤.该算法不仅程序实现简单,而且具有通用性强、本质并行的优点.仿真结果表明了该算法的优越性和通用性.     

有限字长影响下定点滤波器的稳定性分析

针对飞控软件的精度测试,结合实际研究了有限字长影响下定点数字滤波器的稳定性,分析了乘积舍入与补码溢出对系统的非线性影响,给出系统舍入稳定与溢出稳定的定义,获得了系数量化、乘积舍入以及补码溢出等误差共同影响下有限精度系统舍入稳定且溢出稳定的充分条件。     

一种基于数字AGC的定点字长控制算法研究与实现

对数字信号处理中定点计算字长保留问题进行了研究.首先分析了定点计算中截短量化噪声、保留字长与信噪比损失的关系;而后针对信号定点处理中的多次字长截短问题,给出一种基于数字AGC的字长截短控制算法,并在FPGA硬件平台上对算法进行了验证.理论分析和验证结果表明,该算法能够适应输入信号的变化,保证处理流程中的有效量化位数与量化信噪比.     

小波变换硬件实现中有限字长效应的分析

对小波变换硬件实现有限字长的产生和影响进行分析,并提出解决方法。对JPEG2000压缩编码标准中5／3和9／7小波变换,提出采用分数逼近小数的方法实现,比较小数系数和分数系数的变换结果,证明采用分数格式可以在有效的降低硬件实现复杂性的同时,提供相近的变换结果;通过扩大原始信号(左移若干比特)和对中间结果进行合理舍入的方法减小硬件实现中有限字长对变换精度的影响。     

Z变换和Δ变换的有限字长特性研究

计算机的有限字长对数字控制器的实现有重要影响。本文介绍了△变换及其δ算子的数字控制器的实现方法,证明了δ算子实现方法在系数有限字长表示、运算中对舍入及截尾误差的影响;有限字长非线性因素对极限环振荡的影响等方面,都优于常用的z变换及其q算子的数字控制器实现方法。本文还提供了某型飞机的数字控制器在z变换和△变换下的不同有限字长特性的数字仿真。     

Z变换和△变换的有限字长特性研究

计算机的有限字长对数字控制器的实现有重要影响.本文介绍了△变换及其δ算子的数字控制器的实现方法,证明了δ算子实现方法在系数有限字长表示、运算中对舍入及截尾误差的影响;有限字长非线性因素对极限环振荡的影响等方面,都优于常用的z变换及其q算子的数字控制器实现方法.本文还提供了某型飞机的数字控制器在z变换和△变换下的不同有限字长特性的数字仿真.     

机载SAR天线稳定平台的DSP数字控制器设计

机载SAR(airborne Synthetic Aperture Radar,合成孔径雷达)中,用三轴稳定平台隔离载机的姿态变化及机械振动来稳定天线波束指向是关键的运动补偿技术之一。本文提出用TMS320LF2407DSP芯片设计机载SAR三轴陀螺稳定平台的数字控制器,介绍了机载SAR对稳定平台的要求和TMS329LF2407DSP芯片用于运动控制器设计的优点,给出了控制系统的原理方框图、数学模型和DSP数字控制器结构图。     

Two approaches based on pole sensitivity and stability radius measures for finite precision digital controller realizations

This paper compares the two approaches based on pole sensitivity and the complex stability radius measures, respectively, for optimizing the closed-loop stability robustness of digital controllers with respect to finite word length (FWL) errors in fixed-point implementation. Design details and related optimization procedures are derived for the two methods. The two measures, although derived from different motivations, can both be regarded as lower-bound measures of a true but computationally intractable FWL stability measure in some senses. An example is used to verify the theoretical analysis and to illustrate the two designs for determining optimal FWL controller realizations.     

Kolmogorov-Chaitin Complexity of Digital Controller Implementations

The complexity of linear, fixed-point arithmetic digital controllers is investigated from a Kolmogorov-Chaitin perspective. Based on the idea of Kolmogorov-Chaitin complexity, practical measures of complexity are developed for state-space realizations, parallel and cascade realizations, and for a newly proposed generalized implicit state-space realization. The complexity of solutions to a restricted complexity controller benchmark problem is investigated using this measure. The results show that from a Kolmogorov-Chaitin viewpoint, higher-order controllers with a shorter word-length may have lower complexity and better performance, than lower-order controllers with longer word-length.     

Comparative study on optimizing closed-loop stability bounds of finite-precision controller structures with shift and delta operators

The paper analyzes the sensitivity of closed-loop stability with respect to (w.r.t.) finite word length (FWL) effects in the implementation of the controller coefficients using both the shift and delta operator parameterizations. A unified approach is established to optimize a closed-loop stability lower bound for FWL controller structures. This provides a general framework to compare the FWL closed-loop stability characteristics of the controller structures based on the shift and delta operators, respectively. Two numerical examples are given, and the simulation results show that the optimal FWL controller realizations with the delta operator have better closed-loop stability margins than those with the shift operator.     

一种具有通用结构的数字式实时控制器的研究

介绍一种具有通用结构的实时控制器的硬件和软件结构,利用这种结构设计的分级并行式数字式位置控制系统在机器人位置控制中的应用。用实时中断与查询技术相结合的方式处理与硬件直接相关的实时控制问题。系统中以 ＰＣ为上位机,下位机为高性能单片机,由双端口ＲＡＭ构成的共享存储区作为上、下位机实时通信的通道。     

On the stability radius of a Schur polynomial

The robust Schur stability of a polynomial with uncertain coefficients will be investigated. The stability hypersphere for such polynomials will be determined in terms of Tshebyshev Polynomials.     

A Riccati equation approach to maximizing the stability radius of a linear system by state feedback under structured stochastic Lipschitzian perturbations

The object of this paper is to maximize the stability radius of a linear state space system by state feedback under Lipschitzian structured stochastic perturbations. The supermanl achievable stability radius is characterized via the resolution of a parametrized Riccati equation and a matrix inequality. The dependence on the parameters is investigated and the limiting behaviour is examined. An example illustrating the results is treated at the end of the paper.     

On the stability radius of control systems with interval plants and first‐order controllers

This paper considers the stability radius problem of control systems with interval plants and first‐order controllers. The nominal plant P₀(s) used for the controller design is the centre of the interval plant. Under the condition that a lead controller C(s) stabilizes P₀(s), the stability radius of the closed‐loop system is determined in terms of the eigenvalues of four frequency‐independent matrices of the form H⁻¹_{β, i}H_{γ, i}, where both H_{β, i} and H_{γ, i} are Hurwitz‐like matrices. Copyright © 2000 John Wiley & Sons, Ltd.     

The asymptotic behavior of the stability radius for a singularly perturbed linear system

In this paper we study the asymptotic behavior of the stability radius of a singularly perturbed system when the small parameter ε tends to zero. It is proved that for such systems the stability radius tends to the min(r₁,r₂), where r₁ is the inverse of the H_∞-norm of the reduced slow model and r₂ is the stability radius of the boundary layer system. © 1998 John Wiley & Sons, Ltd.