Diamond Tool Grinding Pressure Of Adaptive Control Technology

Natural diamond cutter is one of important tools for Single Point Diamond Cutting and relative researches. Because of brittleness and other special characters, diamond cutter is apt to be cracked or worn in the form of thermo-chemistry wearing and diffusion wearing in high temperature environment. It is very difficult to grind natural diamond cutters with high precision requirements. According to experience of cutter grinding, normal pressing force applied on the grinding surface is one of important factors to affect tool's blade quality. And in the process of diamond tool grinding, the force is required to be small and to be kept very steady. Thus, the control of small steady pressing force is the key technology to get high quality diamond tool and is also the main goal which this thesis aimed at.The main factors, which causing the fluctuation of pressing force in the control system of diamond cutter grind, are analyzed based on "small pressing force steady control" first. Considering the periodical character of the disturbing forces in grinding, the applicability of negative and positive vibration isolation to control low frequency and high frequency disturbing forces is analyzed respectively. Pressing force controlling model is established based on vibration theory, processes and results that disturbing force and positive controlling displacement affect to the model are analyzed respectively and simultaneously. The applying conditions of positive and negative vibration isolator are also deduced.In order to restrain the high frequency disturbing force, a flexible force adjusting platform with ellipse flexure in its symmetry structure is designed as a negative vibration isolator. Structure parameters of the platform are calculated by means of material mechanics theory, and its static and dynamic performances are calculated and simulated using Finite Element Methods in ANSYS Software and tested by static loading experiments and dynamic vibration experiments. Both simulations and experiments show that the stage has good static and dynamic performances and can be used as negative vibration isolator in normal pressure controlling system.In order to enhance the capability of low frequency isolation of the system, adaptive controlling algorithm of Predictive Functional Control is adopted in positive vibration isolator, so as to meet the needs of real time control and the control robustness, and then the displacements controlled are corrected by Iterative Learning Control algorithm according to the periodical characters of disturbing force in diamond tool grinding process. The stability and robustness of control algorithms are proved mathematically and the simulation are carried by Matlab software, and the final force is testified in general controlling experimental system. The results of the test experiments reveal that the force control system has good control capability for disturbing force in rang of 20～160 Hz, and the amount of force decline is more than 30%. The performance of experiment device, however, is hard to be improved because of too low responding velocity of the motion stage and too long sampling period of control system, which should be substituted or improved with more powerful component and apparatus in the real application.