对于步进电机的每个离散步骤使得系统的惯性使电机略微过冲（或下冲）预期的步骤角度。然后电动机振荡，或“环”直到它最终在命令位置沉淀。如果这些逐步振荡的频率位于电机的固有频率附近或接近电机的固定频率，则电机的稳定时间将增加并且可能发生振动和可听噪声。这被称为谐振，如果变得严重，它可能导致电机失去步骤甚至失速。
所有物体都具有自然，或谐振，频率在没有任何阻尼力的情况下振动。对于经典的弹簧质量系统，谐振频率是弹簧常数和质量的函数。
ω.0= resonant frequency of a spring-mass system (rad/s)
k =弹簧常数（n / m）
m = mass（kg）
For a stepper motor system, the resonant frequency is a function of the motor’s torque constant and the system inertia. (Note that the电机resonant frequency is a function of therotorinertia, but in stepper motorsystems, it’s the inertia of themotor-load combinationthat’s important.)
ω.= resonant frequency of a stepper motor system (rad/s)
K = torque constant (Nm)
J =系统（电机+负载）惯性（KGM2)
有几种方法可以减少步进电机系统中的谐振，最简单的方法通常是改变系统的惯性。用户可以通过两种方式执行此操作 - 通过在电机和负载之间添加机械阻尼器或通过adding a gearbox到系统。
Mechanical dampers for stepper motors range from simple elastomer rings that absorb and dissipate vibration energy, totuned mass dampers，这旨在匹配和对抗系统的固有频率。
Image credit: Moons’
添加变速箱提供了两个好处。首先，通过降低载荷惯量来降低总系统惯性。（回想起那个when a gearbox is used, the load inertia is divided by the正方形齿轮比）。并且当电源通过齿轮箱从电动机传输时，电机必须为给定的输出速度旋转到负载，因此电机在其自然频率或附近运行的可能性较少。
The stepper drive’s control method can also affect the amount of vibration that the motor experiences. Case in point, operating a motor withmicrostepping controlgives the benefit of smaller torque variance with each step, since the build-up and decay of current in the windings is more gradual. Even though overshooting (or undershooting) is still possible with microstepping, it will be less significant than with full-step operation, so settling time and vibrations will be lower.
图像信用：新日本广播有限公司
五相步进电机也具有比典型的2相电动机更小的台阶角。与Microstepping一样，较小的步长意味着每个步骤需要较少的电流，因此发生的任何振动都不太严重。随着更多的阶段（五个与两个）有助于输出扭矩，电机经历更低的扭矩波动，又较少，振动更少。
Image credit: Oriental Motor
From a manufacturing standpoint, a stepper motor’s tendency to vibrate can be reduced by changing the rotor inertia (through material or design changes) and by altering the size of the air gap between the motor and stator, which in turn, changes the motor’s torque stiffness. Manufacturers also offer stepper motor drivers that monitor and precisely control current in the motor windings to provide smooth operation, minimize vibrations, and avoid resonance.
Filed Under:运动控制提示
