| With the rapid development of science and technology,optical surfaces with complex microstructures are increasingly used in a range of scientific and technological fields such as aerospace,communications,medicine,military and so on.These surfaces usually have some complex topographies that need high processing requirement and long processing time.Obviously,the conventional machining and processing methods have been difficult to meet the growing demand.The fast tool servo(FTS)processing technology with own high frequency response and high efficiency,can well solve the core problems for complex surface processing.At present,the processing strokes of FTS are relatively short in domestic.Based on this situation,the paper attempts to develop a FTS device with a large working stroke,and conduct related tests.The main contents are expressed as follow:1.According to the design requirements of the large stroke,the paper will choose own mode of motion from the comparison of the four driving modes and the two guiding structures.So “the voice coil motor + aerostatic guide” route was selected.From the stress analysis point of view,the inertia force,cutting force and friction force are calculated to complete the selection of the voice coil motor.Mathematical modeling of the FTS device gets transfer function,and tests response simulation.2.Porous restrictors was tried to use as aerostatic guide.Permeability of the porous material and whether it was within the scope of the air hammer phenomenon were tested by experiment.According to the design requirements and the actual situation,a rectangular closed structure of aerostatic slider was selected and a mathematical model was established.On account of the derivation of the model,the bearing capacity and stiffness of the aerostatic slider were obtained,and the best working operating position was selected.3.The control system for the FTS comprised the PMAC controller,Elmo drive and RENISHAW scale.The parameter setting of the driver and the PID setting of thecontroller,and relevant response tests were completed.4.A high-precision MTI capacitive sensor was used to build a test platform.The positioning,stability and work frequency response of the FTS was tested.Processing experiment platform was set up to make a sector microstructured surface.The experimental results verified that the FTS device has a large working stroke to process micro features. |
