| Profile grinding is widely used in the machining of profile curve parts,such as all kinds of precision complex moulds and cutting tools.In order to meet the requirements of higher precision in rapid processing profile curve parts,it becomes an important research subject to improve the machining accuracy and efficiency of profile grinding.As an effective method,machining error detection and compensation has been used in the traditional optical profile machine to improve machining accuracy.But there are still some problems to be solved,such as low efficiency,lack of stability,bad compensation effect,etc.Therefore,an in-suit method to detect profile error in profile grinding was studied in this paper.Researches and experiments of online error detection and compensation were discussed.The main contents and results are as follows:(1)The dynamic image acquisition in profile grinding was proposed.The principle of profile grinding based on machine vision was introduced.The vision measuring system was designed and calibrated.At the same time,the factors of process which affect the image quality including vibration,spark and cuttings were analyzed.An optimized design of vision measuring system was proposed,which was testified to be capable of obtaining highquality dynamic images during processing.(2)In-situ methods to measure grinding wheel profile and workpiece profile were put forward.The principle of in-situ profile detection based on machine vision was introduced.The methods for detecting grinding wheel profile and workpiece profile were presented respectively.Furthermore,profile measurement experiments were designed and conducted.The results proved the accuracy of the proposed in-situ profile measurement method.(3)A new online error detection method based on global image was put forward.The principle and implementation of online error detection were introduced.The algorithm efficiency was studied and improved.Grinding processing experiments were designed and the results proved that the variation of machining error can be detected accurately by this online error detection method.(4)A novel online error compensation method was proposed.The principle and implementation of error compensation based on virtual axis technique was presented.The simulation tests were carried out to select optimized parameters of the compensation.Experiments of online error compensation were executed and the results showed that the proposed error compensation method could effectively reduce machining error.Finally,an error separation based online error compensation algorithm was proposed for further improving the machining accuracy of profile grinding. |
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