The development and application of high-end CNC machine tools have put forward higher requirements for CNC systems. Among them, high-speed and high-precision motion control has become the key technology of modern CNC systems. It has received widespread attention at home and abroad, and a lot of research has been carried out from theoretical methods to practical applications. Practice has effectively promoted the technological progress of high-end CNC machine tools.
The goal of CNC machining is to achieve high speed, high precision and high efficiency machining. How to ensure the optimal acceleration and deceleration control law aiming at the shortest transition process time under the premise of smooth movement of the machine tool, so that the machine tool has the acceleration and deceleration characteristics that meet the requirements of high-speed machining, is the key problem of acceleration and deceleration research.
There are two types of acceleration and deceleration control schemes: pre-acceleration and deceleration control and post-acceleration and deceleration control: the pre-acceleration and deceleration control is generally located before interpolation and after interpolation preprocessing. The object of the acceleration and deceleration control is the commanded feed rate; the post-acceleration and deceleration control is usually After the interpolator and before the servo controller, control the feed speed of each motion axis, etc. The post-acceleration and deceleration control does not need to calculate the deceleration point, the algorithm is relatively simple, but if the servo gain of each motion axis is different, it is easy to cause a large trajectory contour error and affect the motion accuracy.
Therefore, the current main application of acceleration and deceleration control technology. The acceleration and deceleration control methods can be summarized as traditional acceleration and deceleration methods and flexible acceleration and deceleration methods: traditional acceleration and deceleration methods include trapezoidal acceleration and deceleration methods and exponential acceleration and deceleration methods; flexible acceleration and deceleration methods include trigonometric acceleration and deceleration methods, S curve acceleration and deceleration methods And polynomial acceleration and deceleration methods. Traditional trapezoidal and exponential acceleration and deceleration affect the smoothness of motion due to the sudden change of acceleration. Flexible acceleration and deceleration are attracting more attention in high-speed machining due to the continuous acceleration.