中文摘要：

针对超精密定位平台的高精度要求，以及气浮轴承的刚度和阻尼相对于气膜厚度的变化存在明显的非线性特性．在分析超精度气浮定位平台的基础上，建立了气浮定位平台直线运动的数学模型和基于滑模控制器（SMC）的系统控制模型，并进行了参数分析和实验研究．结果表明：气浮刚度的增大和阻尼的存在有利于改善平台的定位精度，SMC具有较好的鲁棒性，在受外界干扰较大且存在较大非线性情况下，定位平台仍能达到较好的定位精度．

英文摘要：

For the request of ultra-precision of the positioning stage with air-thrust bearings and the outstanding nonlinearity of the stiffness coefficient and damp varying with ＂the air gap, the mathematic models of the linear motion stage with air-thrush bearing and the system control model with sliding mode controller （SMC） are established. The analysis of the parameters is carried out too. The results show that the increasing of stiffness coefficient and the existence of the damp are in favor of the im provement of the positioning accuracy, and the SMC employs good robust; the stage system can reach high positioning precision even though there are stronger disturbance and higher nonlinearity in the system.