基于自适应逆控制的热壁热流逆估计研究

In order to meet with these pressing needs for the experimental measurement of hot-wall heat flux from precisely aerodynamic heating prediction, ground aerothermodynamic tests and flight experiments, hot-wall heat flux inverse estimation will be studied and developed in this item because these classic cold-wall heat flux can not shed light on dynamical thermal response of true heat shielding materials during aerodynamic heating. Due to the fact that there are existing the time-varying thermophysical properties and boundary conditions along with dynamical heating and temperature-elevating process, the fundamental study on hot-wall measurement need to be carried on by new methods and technical approaches. In this study item, a established hot-wall heat flux sensor is equivalently regarded as the controlled object with the linear or nonlinear dynamical characteristics, in which hot-wall heat flux is assumed as the control input variable and the temperature response is the output variable of the controlled object. Then, when the actual output of the object is used as the desired controlled trajectory, the adaptive inverse estimator will be designed based on the adaptive inverse control theories of linear and nonlinear dynamical systems, which make the estimated output values to fit the desired controlled trajectory and then one hot-wall heat flux inverse estimation theory and method with certain robust and higher accuracy is established. Finally, based on above inverse estimation method, one kind of hot-wall heat flux sensor and its measurement technology will be developed in these hypersonic ground aerothermodynamic tests and model flight experiments.

为了满足高超声速飞行器气动热环境预测、地面模拟气动热试验和飞行试验对热壁热流测试迫切需求，针对常规的冷壁热流测试方法无法真实反映模型材料及结构在气动加热过程中动态热响应过程的局限性，本项目拟开展面向防热材料的热壁热流逆估计研究。由于防热材料传热体在动态加热温升过程中通常涉及到难以准确预知的复杂时变热物性参数及传热边界条件，因此需要采用新的研究方法和手段，深入开展热壁热流测试基础性研究工作。本项目拟把构造的热壁热流传感器等效为具有线性/非线性动态特性的被控对象，热流输入为控制输入，温度响应为被控对象输出；然后基于线性/非线性动态系统自适应逆控制理论，把被控对象实际输出作为期望轨迹，开展自适应逆控制器设计,实现被控对象输出与期望轨迹的跟踪，建立具有鲁棒性强以及估计精确度高的热壁热流逆估计理论与方法；在此基础上，发展一种适合高超声速飞行器地面防热试验/模型飞行试验的热壁热流传感器及其测量技术。

针对常规的冷壁热流测试方法无法真实反映模型材料及结构在高超声速气动加热过程中动态热响应过程的局限性，本项目开展了面向非烧蚀型高温合金钢防热材料的热壁热流逆估计研究。本项目研究内容及途径包括：把热流传感器等效为具有线性/非线性动态特性的被控对象，热流输入为控制输入，温度响应为被控对象输出；然后基于线性/非线性动态系统自适应逆控制理论，把被控对象实际输出作为期望轨迹，开展直接和间接自适应逆控制器设计,实现被控对象输出与期望轨迹的跟踪，建立了具有鲁棒性强以及逆估计精确度高的线性动态/热壁热流逆估计理论与方法；在此基础上，分别研制出线性动态热流传感器以及非线性动态热壁热流传感器，并完成了数值仿真、标定试验与电弧风洞试验验证与考核。相关仿真与试验结果表明：1）结合线性动态热流传感器，基于PID控制的动态热流逆估计方法正向传热模型辨识误差约为0.3%，热流逆估计误差为1.3%，中低热流情况下有效测试时间大于25秒；2）结合所研制的热壁热流传感器，建立的基于直接自适应逆控制的动态热壁热流逆估计误差为5.4%，最高测试热流水平达到2.5MW/m^2，响应时间约为0.1秒；建立的基于模型预测控制的间接动态热壁热流逆估计误差为1.8%。本项目研究成果为后续开展模型飞行试验以及电弧风洞多类型非烧蚀型防热材料热壁热流测试奠定了相应测试基础。.受本项目资助发表（含录用）的学术论文共7篇，其中SCI收录2篇，EI收录4篇；已授权发明专利2项，实用新型专利1项；申请受理发明专利5项，实用新型专利1项目；已培养硕士研究生1名。.通过上述研究，项目全面完成了研究计划内容，达到了预期目标。项目直接经费预算55万元，决算35.085万元，经费执行率63.8%。