Improved S curve acceleration and deceleration control method based on trigonometric function

Abstract

The invention relates to an improved S curve acceleration and deceleration control method based on a trigonometric function and belongs to the motion control field. According to the method, a curve isdivided into stages according to different motion characteristics, in the planning process, whether each stage exists is discussed through parameter restriction and actual situations to acquire the operation time of each stage, and a displacement curve after planning is acquired. On the basis of acceleration and deceleration of a traditional S curve, the acceleration and deceleration control method based on the trigonometric function is introduced, acceleration and deceleration continuity can be effectively guaranteed, and impact on numerical control equipment is reduced to the maximum degree.

Description

Technical field: [0001] The invention relates to an improved S-curve acceleration and deceleration control method based on trigonometric functions, belonging to the field of motion control. Background technique: [0002] Acceleration and deceleration control is the key technology in the CNC system. A good acceleration and deceleration control method can effectively avoid the impact, loss of step or vibration during the movement of the CNC equipment, improve the processing accuracy and display quality, and realize the speed of the CNC machine tool. Response, reach the specified speed in a short time, shorten the acceleration and deceleration time, and improve the production efficiency. [0003] At present, the commonly used acceleration and deceleration control methods in CNC systems include: linear acceleration and deceleration, exponential acceleration and deceleration, trigonometric function acceleration and deceleration, and S-shaped acceleration and deceleration. The linear ac...

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Problems solved by technology

The linear acceleration and deceleration algorithm is simple and time-consuming, but the acceleration curve is discontinuous, there is a sudden change in speed, and various vibrations and noises are prone to occur, which will cause flexible impact on the movement of CNC equipment. It is suitable for low-speed and low-cost applications that do not require high movement accuracy CNC system

The smoothness of the exponential acceleration and deceleration algorithm is better than that of the linear acceleration and deceleration algorithm, and the motion accuracy is high, but the acceleration and deceleration starting point and end point of the acceleration and deceleration have sudden changes in acceleration and deceleration, and there is also a flexible impact

Trigonometric function acceleration and deceleration mainly uses the sinusoidal curve between 0-π to construct the velocity curve, and then realizes the continuous derivation of acceleration and jerk, so as to achieve the purpose of smooth and smooth transition, but because the current trigonometric function acceleration and deceleration is guaranteed The speed line type cannot give full play to the performance of the jerk and the maximum allowable value of the acceleration of the CNC equipment, causing the speed to fail to reach the expected value in a short time and distance

Some scholars also use trigonometric functions to construct acceleration and jerk curves, and obtain velocity and displacement curves through integrals. There is also the problem that the performance of CNC equipment cannot be fully utilized in order to ensure the line shape of trigonometric functions.

S-shaped curve acceleration and deceleration has the advantages of continuous acceleration curve and smooth speed curve, which is suitable for high-speed and high-precision machining field applications. However, the current S-curve still has a step change in jerk. On the rising and falling edges of the step change, Cause vibration and shock to the feeding system of CNC equipment, affecting the smooth operation

[0004] Chinese patent document (Application No. 201310095677.3) discloses a trigonometric function second-order continuous derivable acceleration and deceleration algorithm for CNC machine tools. Combining the advantages of the general S-shaped acceleration and deceleration curve algorithm, an improved trigonometric function algorithm is proposed, but In this solution, when the jerk is processed, the jerk is directly reduced from the maximum jerk to 0 in the form of a trigonometric function, and there is a large impact from the beginning, and the jerk is not maintained when it reaches the maximum value, the acceleration efficiency is low, and it takes a long time

The trigonometric function has better ability in the continuity of the curve, but it cannot give full play to the performance of the maximum acceleration and jerk of the CNC equipment, and the execution efficiency is low

The S curve has good speed smoothness, but the jerk is discontinuous, which has vibration and impact on the feeding system of CNC equipment.

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