一种稳健的窄带反馈型主动噪声控制系统

传统窄带反馈型主动噪声控制系统采用并型自适应滤波器结构,用于合成参考信号时,仍存在参考信号合成质量较差、 滤波器权值的初值设置难度高、应对非平稳窄带噪声的能力不足等问题。 为解决以上问题,通过引入高效的串并型自适应滤波 器结构来合成参考信号,提出新型的窄带反馈型主动噪声控制系统,改善参考信号合成质量,进而提升系统的整体降噪性能。 新型系统不仅有效解决了传统系统存在的参考信号合成质量较差的问题,还降低了滤波器权值的初值设置复杂度,同时还提升 了系统应对非平稳窄带噪声的能力。 实验结果表明,新型系统较传统系统的前后两部分的降噪量分别提升了 7. 89 和 9. 18 dB。 仿真和实验结果共同验证了提出的系统较传统系统具有更强的稳健性和降噪性能。     

基于Matlab的车辆主动悬挂控制研究

建立了一个具有六自由度的客车横向振动力学模型及动力学运动方程,运用线性二次型最优控制方法,用MATLAB软件编写程序并计算出最优反馈矩阵K,并用Simulink进行了仿真计算及分析.结果表明采用主动悬挂技术可以有效改善车辆的横向振动性能.     

Combined MIMO adaptive and decentralized controllers for broadband active noise and vibration control

Model errors in multiple-input multiple-output adaptive controllers for reduction of broadband noise and vibrations may lead to unstable systems or increased error signals. In this paper, a combination of high-authority control (HAC) and low-authority control (LAC) is considered for improved performance in case of such model errors. A digital implementation of a control system is presented in which the HAC (adaptive MIMO control) is implemented on a CPU and in which the LAC (decentralized control) is implemented on a high-speed Field Programmable Gate Array. Experimental results are given which demonstrate that the HAC/LAC combination leads to performance advantages in terms of stabilization under parametric uncertainties and reduction of the error signal.     

Modified-filtered-u LMS algorithm for active noise control and its application to a short acoustic duct

This paper presents a new adaptive algorithm for active noise control (ANC) that can be effectively applicable to a short acoustic duct, such as the intake system of an automobile engine, where the stability and fast convergence of the ANC system is particularly important. The new algorithm, called the modified-filtered-u LMS algorithm (MFU-LMS), is developed based on the recursive filtered-u LMS algorithm (FU-LMS) incorporating the simple hyper-stable adaptive recursive filter (SHARF) to ensure the control stability and the variable step size to enhance the convergence rate. The MFU-LMS algorithm is implemented by purely experimental ways, and is applied to active control of noise in a short acoustic duct, and is validated using two experimental cases of which the primary noise sources are a sinusoidal signal embedded in white noise and a chirp signal. The experimental results demonstrate that the proposed MFU-LMS algorithm gives a considerably better performance than other conventional algorithms, such as the filtered-x LMS (FX-LMS) and the FU-LMS algorithms.     

一种含次级通道在线辨识的窄带主动噪声控制系统

分析了噪声危害设备产生的谐波噪声,特别是以500 Hz或600 Hz以下的低频成分为对象,介绍了主动噪声控制(ANC)技术的原理、意义及发展现状。在实际声学场所,由于控制系统易受初级噪声功率、残余噪声幅值等因素影响而不稳定。在分析控制系统收敛条件的基础上,通过对系统误差引入一个比例因子从而改进系统模型,并以一维管道为实验平台,基于高速数字信号处理器(DSP)设计了含次级通道在线辨识的主动噪声控制器。实验结果表明,在250 Hz左右的频段上能够达到16 dB的降噪效果。     

Fuzzy chaos control for vehicle lateral dynamics based on active suspension system

The existing research of the active suspension system（ASS） mainly focuses on the different evaluation indexes and control strategies. Among the different components, the nonlinear characteristics of practical systems and control are usually not considered for vehicle lateral dynamics. But the vehicle model has some shortages on tyre model with side-slip angle, road adhesion coefficient, vertical load and velocity. In this paper, the nonlinear dynamic model of lateral system is considered and also the adaptive neural network of tire is introduced. By nonlinear analysis methods, such as the bifurcation diagram and Lyapunov exponent, it has shown that the lateral dynamics exhibits complicated motions with the forward speed. Then, a fuzzy control method is applied to the lateral system aiming to convert chaos into periodic motion using the linear-state feedback of an available lateral force with changing tire load. Finally, the rapid control prototyping is built to conduct the real vehicle test. By comparison of time response diagram, phase portraits and Lyapunov exponents at different work conditions, the results on step input and S-shaped road indicate that the slip angle and yaw velocity of lateral dynamics enter into stable domain and the results of test are consistent to the simulation and verified the correctness of simulation. And the Lyapunov exponents of the closed-loop system are becoming from positive to negative. This research proposes a fuzzy control method which has sufficient suppress chaotic motions as an effective active suspension system.     

一种低复杂度快速收敛的窄带主动噪声控制系统

传统窄带主动噪声控制( ANC)系统的计算负荷与窄带噪声频带数量正相关,而且其收敛速度和降噪效果存在此消彼 长的关系。 为解决以上问题,首先基于滤波误差技术简化窄带 ANC 模型,使系统计算量与窄带噪声频带数量相互独立。 然后 通过自适应混合参数将两个简化的窄带 ANC 系统进行并行凸组合,其中一个系统拥有最快的收敛速度,另一个系统拥有较低 的稳态误差。 提出的系统不仅降低了传统窄带 ANC 系统的计算复杂度,而且在不牺牲降噪性能的情况下提升了系统收敛速 度。 实验结果表明,提出系统在不牺牲稳态误差的基础上,收敛时间缩短了 78% ,有效提升了系统收敛性能。     

基于EMD与响度的有源噪声控制系统

为了提高有源噪声控制系统的降噪效果,提出了基于经验模态分解( empirical mode decomposition,EMD)和响度的控制系统.该系统首先采用EMD方法对噪声源进行自适应分解,并对分解后的各个固有模态函数(intrinsic mode function,IMF)分量的响度进行计算,然后根据各个分量的响度大小进行残差滤波器的设计.与基于A计权曲线设计的残差滤波器相比,该方法所设计滤波器能更好地抑制响度较小的信号频率成分.对有源噪声控制系统的降噪效果进行了仿真,结果表明,所提出的控制系统比传统滤波-X LMS(filtered-X least mean square)方法和采用基于A计权残差滤波器的系统降噪效果更好.     

Lateral vehicle control based on active flight control technology

In this paper, a lateral vehicle control using the concept of control configured vehicle (CCV) is presented. The control objectives for the lateral dynamics of a vehicle include the ability to follow a chosen variable without significant motion change in other specified variables. The analysis techniques for decoupling of the aircraft motions are utilized to develop vehicle lateral control with advanced mode. Vehicle lateral dynamic is determined to have the steering input and control torque input. The additional vehicle modes are also defined to using CCV concept. We use right eigenstructure assignment techniques and command generator tracker to design a control law for an lateral vehicle dynamics. The desired eigenvectors are chosen to achieve the desired decoupling (i.e., lateral direction speed and yaw rate). The command generator tracker is used to ensure steady-state tracking of the driver’s command. Finally, the developed design is utilized by using the lateral vehicle dynamic with four wheel.     

Active noise control using a distributed mode flat panel loudspeaker

A flat panel distributed mode loudspeaker (DML) has many advantages over traditional cone speakers in terms of its weight, size, and durability. However, its frequency response is uneven and complex, thus bringing its suitability for active noise control (ANC) under question. This paper presents experimental results demonstrating the effective use of panel DML speakers in an ANC application. Both feedback and feedforward control techniques are considered. Effective feedback control with a flat panel speaker could open up a whole range of new noise control applications and has many advantages over feedforward control. The paper develops a new control algorithm to attenuate tonal noise of a known frequency by feedback control. However, due to the uneven response of the speakers, feedback control is found to be only moderately effective even for this narrow-band application. Feedforward control proves to be most capable for the flat panel speaker. Using feedforward control, the sound pressure level can be significantly reduced in close proximity to an error microphone. The paper demonstrates an interesting application of the flat panel in which the panel is placed in the path of sound and effectively used to block sound transmission using feedforward control. This is a new approach to active noise control enabled by the use of flat panels and can be used to prevent sound from entering into an enclosure in the first place rather than the traditional approach of attempting to cancel sound after it enters the enclosure.     

A novel technique for optimal integration of active steering and differential braking with estimation to improve vehicle directional stability

This study deals with the enhancement of directional stability of vehicle which turns with high speeds on various road conditions using integrated active steering and differential braking systems. In this respect, the minimum usage of intentional asymmetric braking force to compensate the drawbacks of active steering control with small reduction of vehicle longitudinal speed is desired. To this aim, a new optimal multivariable controller is analytically developed for integrated steering and braking systems based on the prediction of vehicle nonlinear responses. A fuzzy programming extracted from the nonlinear phase plane analysis is also used for managing the two control inputs in various driving conditions. With the proposed fuzzy programming, the weight factors of the control inputs are automatically tuned and softly changed. In order to simulate a real-world control system, some required information about the system states and parameters which cannot be directly measured, are estimated using the Unscented Kalman Filter (UKF). Finally, simulations studies are carried out using a validated vehicle model to show the effectiveness of the proposed integrated control system in the presence of model uncertainties and estimation errors.     

Robust absolute stability analysis for interval nonlinear active disturbance rejection based control system

Active disturbance rejection control (ADRC) is a relatively new, quite different but very practical control technology, which shows much promise in replacement of proportion-integration-differentiation (PID) with unmistakable advantage in performance and practicality. This paper mainly concerns with the robust absolute stability of the ADRC based control system with parameter perturbations of the plant, i.e., ADRC based interval control system. Firstly, the system is transformed into a perturbed indirect Lurie system. Then, the Popov criterion and its robust version are presented and some new methods are developed to analyze the (robust) absolute stability for the interval control system. Furthermore, an example is presented to illustrate (robust) absolute stability analysis via the above methods, which verifies the convenience and practicability of these methods and shows the strong stability robustness of ADRC in the presence of parametric uncertainties.     

主动噪声控制技术及其在车内噪声控制中的应用

主动噪声控制是集声学、自适应控制及数字信号处理等技术为一体的高新技术,已成为国内外噪声控制界的研究热点。基于主动噪声控制的Swinbanks多极子系统理论,证明了主动噪声控制技术适合于低频．1k的理论依据。阐述了决定主动噪声控制效果的决定因素及在车内噪声控制中应用的发展过程,并指出当前研究中需解决的问题和今后的研究方向。     

车辆悬架主动控制系统发展现状和趋势

悬架系统是车辆主要减振机构,对改变车辆性能有很大作用.悬架系统的主动控制技术能大大改善悬架系统的作用,介绍了主动悬架技术以及其发展现状.并对主动悬架系统的发展前景作了预测分析.     

Simulation on a car interior aerodynamic noise control based on statistical energy analysis

How to simulate interior aerodynamic noise accurately is an important question of a car interior noise reduction. The unsteady aerodynamic pressure on body surfaces is proved to be the key effect factor of car interior aerodynamic noise control in high frequency on high speed. In this paper, a detail statistical energy analysis (SEA) model is built. And the vibra-acoustic power inputs are loaded on the model for the valid result of car interior noise analysis. The model is the solid foundation for further optimization on car interior noise control. After the most sensitive subsystems for the power contribution to car interior noise are pointed by SEA comprehensive analysis, the sound pressure level of car interior aerodynamic noise can be reduced by improving their sound and damping characteristics. The further vehicle testing results show that it is available to improve the interior acoustic performance by using detailed SEA model, which comprised by more than 80 subsystems, with the unsteady aerodynamic pressure calculation on body surfaces and the materials improvement of sound/damping properties. It is able to acquire more than 2 dB reduction on the central frequency in the spectrum over 800 Hz. The proposed optimization method can be looked as a reference of car interior aerodynamic noise control by the detail SEA model integrated unsteady computational fluid dynamics (CFD) and sensitivity analysis of acoustic contribution.     

轨道除沙机试验样机控制系统的开发与研究

针对我国沙害地区埋沙铁路干线的紧急疏通问题,在具有集沙、刮沙、传沙及扬沙等功能的液压轨道除沙机试验样机的机械结构和液压系统原理设计基础上,对PLC控制系统原理图进行了设计.通过在安装有模拟器(GX-Developer)的计算机上编程与调试,验证了该样机控制原理的可行性,为开发轨道除沙机提供了理论与实施基础.     

The stability of active balancing control using influence coefficients for a variable rotor system

High-speed rotating machines can be very sensitive to rotating mass unbalance that is a major source of harmful vibration for many types of rotating machinery. A balancing procedure is therefore needed for all high-speed rotating systems. To save the time and cost of off-line balancing, many researchers have developed on-line balancing devices and methods. In this paper, an active balancing device, which is of an electro-magnetic type, has been developed and an active balancing method using the influence coefficient method is proposed. The stability of active balancing control is studied in this paper. A stable condition for active balancing control is derived by estimating the errors of influencing coefficients. A gain scheduling control using influence coefficients of the standard model is proposed when the dynamic characteristics of a rotor system are changed. The stability of the balancing method is verified by experiments.     

电梯水平振动主动控制实验系统及仿真

介绍了电梯水平振动主动控制实验系统。导出了实验系统的振动微分方程和数学模型；在MATLAB／SIMULINK环境下仿真了实验系统的水平位移和加速度响应以及基于LQR最优控制的主动控制策略。仿真结果表明，该实验系统对电梯水平振动主动控制和其它方面的研究是可行的。     

神经网络-遗传算法在振动控制系统中的应用

分析了欧拉-伯努利梁的振动特性,提出了将遗传算法及神经网络应用于欧拉-伯努利梁振动主动控制的新方法.该方法利用遗传算法在线计算控制力,利用神经网络模拟粱的动力特性,代替梁进行动力分析.系统充分发挥了遗传算法及神经网络各自的特点,是非常具有发展前途的新型的控制系统.