A review of recent advances in machining techniques of complex surfaces

Complex surfaces are widely used in aerospace, energy, and national defense industries. As one of the major means of manufacturing such as complex surfaces, the multi-axis numerical control (NC) machining technique makes much contribution. When the size of complex surfaces is large or the machining space is narrow, the multi-axis NC machining may not be a good choice because of its high cost and low dexterity. Robotic machining is a beneficial supplement to the NC machining. Since it has the advantages of large operating space, good dexterity, and easy to realize parallel machining, it is a promising technique to enhance the capability of traditional NC machining. However, whether it is the multi-axis NC machining or the robotic machining, owing to the complex geometric properties and strict machining requirements, high-efficiency and high-accuracy machining of complex surfaces has always been a great challenge and remains a cutting-edge problem in the current manufacturing field. In this paper, by surveying the machining of complex parts and large complex surfaces, the theory and technology of high-efficiency and high-accuracy machining of complex surfaces are reviewed thoroughly. Then, a series of typical applications are introduced to show the state-of-the-art on the machining of complex surfaces, especially the recently developed industrial software and equipment. Finally, the summary and prospect of the machining of complex surfaces are addressed. To the best of our knowledge, this may be the first attempt to systematically review the machining of complex surfaces by the multi-axis NC and robotic machining techniques, in order to promote the further research in related fields.