Simultaneous estimation of sensor locations during thermal property parameter estimation

摘要

The temperature dependent thermal properties of a material may be evaluated from transient temperature histories using nonlinear parameter estimation techniques. The usual approach is to minimize the sum of the spuared errors between measured and calculated temperatures at specific locations in the body. The location of the temperature sensors in the material is usually considererd as known and fixed during parameter estimation computations. In fact, sensor locations are never known exactly; location errors on the order of the sensor dimensions are intrinsic to most instrumentation proedures. Sensor ocation errors are especially significant when estimating the thermal properties of low diffusivity materials which can sustain large temperature gradients during testing. In this paper, a parameter estimation formation is presented which allows for the direct inclusion of sensor position into the primary parameter estimation procedure. It is demonstrated that this procedure can lead to increased accuracy in estimated thermal properties. A mathematical outline of the procedure is given and its implementation is illustrated through numerical examples characteristic of light-weight, temperature cernamic insulations during transient heating.