Processing Control On Complex Parametric Curve And Surface And Condition Monitor

In the modern equipment manufacturing, the key technique is numeric control, which determines the machine manufacturing level of a country. One of the key techniques in numeric control is interpolation, and the chord deviation of curve and surface in interpolation displays the core technology. This dissertation intends to work on the theory and application on this problem.In the process of component finishing in numeric control, the chord deviation in interpolation is scale with surface roughness of the component finishing. Due to the complexity of chord deviation calculation, we propose the chord deviation control algorithm in complex parameter curve manufacturing. It indirectly controls the chord deviation in the way of employing arc-length error, coordinate values and first order derivative in the interpolation points. The arc-length error in the interpolation points is calculated by the Simpson Formula, and the coordinate values and first-order derivative in the points are achieved by interpolation algorithm, as a result the calculation does not increase too much. This paper discusses the error of the algorithm, and uses simulation results of Nurs curve to testify that this algorithm can achieve accuracy of the chord deviation as 2.587 83×10-6mm under the assumption that the calculation of single interpolation is no bigger than 300μs.The chord derivation is the key factor in the surface quality of component finishing. Combination of the algorithm proposed in this paper and the parameter surface high accuracy cutting tool trajectory algorithm with the error compensation can control the chord deviation in a certain range with the satisfaction of real-time. It reaches the predetermined accuracy in the component finishing, and the nature of it is to improve the component quality by changing the feed speed in real-time. In the process of calculating the chord derivation, many necessary data are already there in applying the parameter surface high accuracy cutting tool trajectory algorithm with error compensation, and do not need to compute again. It just requires simple calculation for the arc-length error in the interpolation points and gets the chord deviation. No increase of computation appears since it does not need to directly calculate second order derivation for the chord deviation. Meanwhile, this algorithm is suitable for the various parameter curve interpolation and chord deviation control in the interpolation points with continuous first order derivation and existing second order deviation.Screw gear is used to producing with screw gear NC machine. Due to the high price and low utilization ratio when employing special equipment, it's not suitable for single screw gear or small batch. Based on this, we focus on producing the screw gear with five-axis NC machine, and develop NC processing system based on the TDNC-H8 which is an open NC system. This new system has the function of cutting simulation in real-time, and this function employs the algorithm of Slice method. It computes faster and has higher accuracy compared with former screw gear simulation algorithm.Based on the signal sampled type, sampling method, signal analysis, state identification, monitoring and diagnosis, this paper studies on the sampling analysis and implementation of the unstable signal of rotating parts. We also propose a fault extraction technique based on order analysis and a state identification method of AR model, and implement experiments under Linux. This paper applies the above algorithm and monitoring & analysis on TDNC-H8, which is a five-axis NC Spiral bevel gear manufacturing system developed by Tianjin University. The results show that the proposed methods can greatly promote the manufacturing technology on curves and surfaces.