出汗假人系统特征方程与稳定性判定

采用实验方法,通过出汗假人皮肤表面温度和湿润度的单位阶跃响应,求得系统的结构参数阻尼比ξ和自然振荡频率ωn,判定该出汗假人系统的稳定性。实验结果表明:假人皮肤表面温度控制过程的阻尼比ξ为0.804,说明皮肤表面温度控制系统为欠阻尼二阶系统,振荡过程为衰减振荡,且自然振荡频率ωn为0.004 6,温度控制过程平稳性较好;假人出汗控制过程的阻尼比ξ为0.643,说明出汗控制系统也为欠阻尼二阶系统,振荡过程为衰减振荡,自然振荡频率ωn为0.002 8,出汗控制过程平稳性也很好。

Characteristic equation and stability determination of sweating manikin

The two parameters(damping ratio ξ and nature surge frequency ω_n) of the system are obtained through the step response curve of sweating manikin.According to the values of ξ and ω_n,the stability of sweating manikin system can be determined.The experimental results show that in the control process of manikin surface skin temperature,when ξ is 0.804,it illustrates that this control system is an underdamping second-order system.The surge process is attenuation.When the nature surge frequency ω_n equals to(0.004 6),the stability of this control process is very good.In the control process of manikin surface wetness,when ξ is 0.643,it illustrates that this control system is also an underdamping second-order system.The surge process is attenuation,too.When the nature surge frequency ω_n equals to(0.002 8),the stability of this control process is also very good.