Study On Precision Measurement And Grinding For Radome Inner Surface

Radome is one of the key parts of the active homing guidance weapon, which is a large complicated shell solid of revolution made of hard and brittle material. Its inner surface is 3-D high-degree-power complicated surface. The machining precision of the radome directly affects the boresight precision. However, the semi-finished radome always can't meet the requirement for electromagnetic properties because of the error of the electric thickness resulted from the error of the geometric thickness and the non-uniformity of the dielectric constant of the material. In attempting to satisfy the electric index requirement of the radome, precision grinding techniques have been developed to machine the inner surface of the radome according to the electric thickness data in order to compensate the electric thickness error by altering the geometric thickness. This precision grinding for compensating electric-thickness differs greatly from the general grinding. Firstly, the machining reference surface is the actual inner surface of semi-finished radome, which is a three-dimensional complicated surface; secondly, the grinding quantities at different locations on the radome vary from each other.In this paper, according to the technical requirement of the radome, based on the analysis of parameters of electromagnetic properties, the machining principle as well as the way of determining grinding allowance has been studied. Meanwhile, the designing idea, the construction principle and the realization scheme of the equipment for precision measuring and grinding of the radome have been discussed. In addition, the whole set of precision machining scheme and the key techniques, which include the measuring principle for the inner surface, the acquisition and processing of the measuring data, the reconstruction of the inner surface and calculation of the tool path, the analysis and calibration of the performance index related to the machine tool and the machining process parameters for the inner surfaces precision grinding of the radome made of fused quartz, have been also studied. All these have enabled us to resolve the precision grinding problem of the inner surface of the radome and have filled up relevant technology gap in China.The actual inner surface is the base for precision machining, and it should be measured first, then the inner surface is reconstructed according to the measuring points to form the relative base for precision machining. Therefore, the accuracy of measuring and reconstruction of the inner surface of the radome is a key to ensuring the grinding precision. Here, the measuring method of the radome inner surface as well as the data processing method were studied, which include calculation of the measuring track, data acquisition, compensation of the measuring head's radius and regularization of the acquired data. Based on this, an algorithm was developed to...