How to achieve the stability of high-speed start stop of servo motors?

In the control of servo motors, the stability of high-speed start stop is mainly affected by the design of the speed curve.
The speed control of servo motors can generally be analogized to a spring mass damper (SD) system. To improve the stability of the system, it is necessary to minimize the damping and stiffness changes of the system at different speeds.

During the start and stop process, the speed change of the motor should be as smooth as possible to avoid sudden changes. This is because the output torque of the motor is directly proportional to the derivative of speed. If there is a sudden change in speed, the torque will also change, which may lead to a decrease in system stability.

There is a method called "5th degree curve acceleration", whose basic idea is to divide the entire acceleration process into several stages, each stage's velocity change is carried out with a constant acceleration, and the acceleration of each stage also conforms to a specific order (such as the first stage is negative, the second stage is zero, and the third stage is positive).

This method can make the torque changes experienced by the motor smoother throughout the entire process, improving the stability of the system. However, the actual effectiveness of this method also depends on specific system parameters and application scenarios. For example, if the stiffness and damping ratio of the system is very large, the effect of this method may not be significant. In practical applications, it may be necessary to optimize the design of the speed curve based on the actual parameters and application requirements of the system.