In order to eliminate the instability of the system caused by the large mismatch between the load inertia and the motor inertia, the following measures can be taken:

1. The first is to improve the stiffness of the mechanical system. (For example, increasing the torsional stiffness of the coupling can increase the frequency of oscillation of the response, while reducing the amplitude of the oscillation)

2. Secondly, use a suitable deceleration mechanism (such as reduction box, synchronous pulley deceleration, etc.) to reduce the mismatch between the load inertia and the motor inertia to the lower limit as much as possible.

3. When the above measures are ineffective, the method of increasing the motor inertia can be adopted to reduce the mismatch between the load inertia and the motor inertia to the lower limit as much as possible. Increasing the moment of inertia of the motor can significantly reduce the resonance amplitude at the resonance point and improve the stability of the servo system. However, it should be noted that the size and cost of the motor generally increase with the increase of the rated torque. Therefore, when selecting a motor with a larger motor inertia for a reasonable inertia ratio, the same torque rating can be selected, but only the inertia is larger. of the motor. In this way, the volume and cost of the motor can be avoided.

4. Another solution is to use a high-level servo drive system that takes into account the amount of twist of the connecting shaft. This system requires the position feedback of the motor body and the position feedback of the load end to form a fully closed-loop system. Such a system can have a faster and more stable transient response.