In our country the national long-term science and technology development plan (2006-2020) "the major high-end CNC machine tools and basic manufacturing equipment, special as one of 16 major national science and technology projects, clearly put forward the goal of development of China's high-end CNC machine tools. High-end CNC machine tools of the development and application of computer numerical control (CNC) system put forward higher requirements, the high speed and high precision motion control becomes the key technology of the modern computer numerical control (CNC) system, has been widespread concern at home and abroad, and from the theory to the practical application of a lot of research and practice, have effectively promoted the technology progress of high-end CNC machine tools.
Acceleration and deceleration Technology
The goal of NC machining is to achieve high speed, high precision and high efficiency. How to guarantee under the condition of stable movement of the machine tool to achieve a transition time is the shortest for optimal target and deceleration control law, so that the machine can meet the requirement of the high-speed machining of acceleration and deceleration characteristics, is the key problem in the acceleration and deceleration of the. Before the acceleration and deceleration control scheme is usually of acceleration and deceleration and acceleration and deceleration control two: before and deceleration control is generally located in the interpolation, the interpolation preprocessing, acceleration and deceleration control is programmed feed rate; after deceleration control usually before interpolation, servo controller, control the movement axis feed speed. After the acceleration and deceleration control no need to calculate the deceleration point, the algorithm is relatively simple, but if the servo gain of each moving axis is different, it is easy to cause a large trajectory profile error, and affect the accuracy of motion. Therefore, the main application of the pre acceleration and deceleration control technology. Acceleration and deceleration control method can induction for traditional acceleration deceleration control method and flexible acceleration and deceleration method: traditional acceleration deceleration control method with trapezoid acceleration deceleration method and exponential acceleration and deceleration control method method; flexible acceleration and deceleration method with trigonometric function and deceleration method and S-curve acceleration and deceleration method and polynomial acceleration and deceleration method etc.. The traditional trapezoidal and exponential acceleration and deceleration due to the existence of the acceleration of the mutation and affect the stability of the movement, flexible acceleration and deceleration due to the acceleration of the continuous, in the high speed machining of much attention.
