Application of the run length encoding algorithm to the fabrication of non-rotationally symmetric surfaces

When a non-rotationally symmetric surface with complex shape is machined in diamond turning machine, Fast Tool Servo(FTS) can be an effective means of fabricating non-rotationally symmetric components. But the size of geometric data describing the surface becomes very large because the depth of cut varies in θ direction as the spindle rotates. Since the FTS controller has a limited capacity of memory, it is very difficult to transfer the data file at one time. The method of splitting the data file into several ones and transferring them to the machine controller by rotary buffer, was undesirable when we have a small amount of memory and there is no more remaining cycle time in FTS controller. In this paper, we propose the method of compressing the large size geometric data file into the smaller ones by run length encoding algorithm. Also, through this algorithm, we can recover the original data file by decompressing the encoded file.