半主动三附气室空气弹簧吸振器特性分析

Characteristic Analysis of Semi-active Triple-auxiliary-chambers Air Spring Vibration Absorber

为了克服被动吸振器吸振带宽窄的局限性,利用空气弹簧的变容积-变刚度特性,采用“复合频响曲线”法的半主动控制策略,设计出一种三附加气室空气弹簧吸振器。建立无源式三附加气室空气弹簧的非线性模型,通过线性化得到空气弹簧的系统传递函数,导出空气弹簧固有频率的解析表达。基于非线性空气弹簧模型,建立了有源式空气弹簧的开环和闭环(PI控制)气动伺服模型,并经过仿真观测了其变容积-变刚度特性。实验采用FFT算法获得激励频率的估计值,基于零极点匹配法设计出无限脉冲响应(Infinite impulse response,IIR)滤波器补偿网络以校正速度传感器带宽,验证了有源式三附加气室空气弹簧的吸振特性。实验结果表明,在有源环境下,通过实时改变附加气室的工作个数,实现了空气弹簧的固有频率有级可调,并跟随激励频率,拓展工作频带,被控对象在1~10 Hz内的共振被有效消除。

To address the constrained vibration absorption bandwidth of passive shock absorbers,a novel solution is proposed in the form of a triple-auxiliary-chambers air spring vibration absorber.This design leverages the variable volume-variable stiffness properties of the air spring and employs the semi-active control strategy known as the"composite frequency response curve"method.Additionally,a nonlinear model is developed for the passive three-additional air chamber air spring,followed by the establishment of the system transfer function through linearization.Finally,an analytical expression for the natural frequency of the air spring is derived.The open-loop and closed-loop pneumatic servo models of active air springs are established using the nonlinear air spring model.Through simulation,the variable volume-stiffness characteristics are observed.In the conducted experiment,the estimated excitation frequency is acquired through the utilization of the fast Fourier transform(FFT)algorithm.Additionally,the infinite impulse response(IR)filter compensation network is devised employing the zero-pole matching technique to rectify the bandwidth of the velocity sensor.Finally,the vibration absorption characteristics of the active three-additional air chamber air spring are verified.The experimental results show that in the active environment,the natural frequency of the air spring can be incrementally adjusted by dynamically altering the quantity of supplementary air chambers.Moreover,the operational frequency range is broadened in conjunction with the excitation frequency,effectively mitigating resonance of the controlled object within the 1-10 Hz range.