Based on the friction model describing the Stribeck effect, in the partially lubricated state, the increase in the sliding speed causes the lubricating film to become thicker and thicker, and the decrease in the number of solid-solid contacts leads to a decrease in friction. In the partially lubricated state, the speed increases and the friction also decreases, although the cause of the drop is completely different from the cause of the critical lubrication state. The reduction in friction caused by an increase in speed is called negative slope friction or Stribeckeffect. Existing problems and research prospects In summary, in order to solve the problem of machine positioning accuracy and tracking accuracy affected by friction, the current research on friction model and compensation technology has made fruitful progress, but still can be perceived. The main issues are as follows. Lack of accurate friction models. The friction characteristics need to be further analyzed to make the established model more intuitive, to more accurately describe the static and dynamic characteristics of the friction, and to facilitate compensation control. The selection of the control atmosphere and the selection of the inlet position for the mesh belt type electric resistance furnace are summarized in practice, and are applied to the design of the electric resistance furnace. The furnace designed according to this method is normally used in dozens of enterprises all over the country. The atmosphere is controllable, the flow in the furnace is reasonable, the furnace is clean, the atmosphere saving effect is obvious, the workpiece color is bright, and the carbon concentration of the workpiece after carburization is evenly distributed. . The heat treatment quality of the products is stable and has produced good social benefits. Because the furnace is clean, the carbon black in the furnace is reduced, and the life of the oxygen probe and the radiant tube, which are important components of the resistance furnace, is doubled. (Finish) Valve Core,Hydraulic Valve Core,Core For Hydraulic Valve,Machining Core For Hydraulic Valve Ningbo MHC Machinery CO LTD , https://www.mhcvacuumparts.com
Research on Compensation Control in CNC Servo Feeding Device
For the former, the parameters of the friction model are obtained by off-line identification and remain unchanged during the control process; for the latter, the parameters are determined by line iterative estimation and are variable during the control process. From the perspective of the commonly used friction model, the common compensation control method based on the table feed servo system has the following five aspects. The advantage of using Coulomb friction model to compensate based on Coulomb friction + viscous model is that the model is simple and easy to implement. However, since the friction model is a static friction model, the nonlinear characteristics of friction at zero speed cannot be described, and its control effect is limited. Therefore, the model is generally not directly applied to the compensation scheme.