伺服阀固有频率的估算

PEN

位置控制总是以90度的相位滞后开始。 位置是速度的积分。 积分增加了90度的相位滞后。

阀门额定值是乐观的。 额定值应在-0 db和不超过45度的相位滞后进行。 135度的相位滞后并不差，但只考虑了阀门和积分速度。 由于气缸和负载，存在相位滞后。 由于控制器及其输入和输出延迟，存在相位滞后。 大多数Bode图仅用于液压缸和负载。 必须考虑液压缸和负载相位滞后。 通常前馈有助于补偿相位滞后。


Position control always starts with 90 degrees of phase lag. The position is the integral of velocity.  The integral adds 90 degrees of phase lag.

The valve ratings are optimistic.  The ratings should be done at -0 db and no more than 45-degree phase lag.  135 degrees of phase lag is not bad but only the valve and integrating velocity have been considered.  There is phase lag due to the cylinder and load.  There is phase lag due to the controller and its input and output delays. Most of the Bode plots have been only for the hydraulic cylinder and load.  The hydraulic cylinder and load phase lag must be considered.  Normally feed forwards will help compensate for phase lag.

back2049

PEN 发表于 2019-8-30 10:45
位置控制总是以90度的相位滞后开始。 位置是速度的积分。 积分增加了90度的相位滞后。

阀门额定值是乐观 ...

伺服阀的相位误差对油缸动态控制的相位差影响有多大？
液压油有压缩性也会造成滞后

PEN

back2049 发表于 2019-8-30 13:16
伺服阀的相位误差对油缸动态控制的相位差影响有多大？
液压油有压缩性也会造成滞后

这就是我所说的气缸和负载的相位延迟。

气缸和负载的相位延迟与每个频率下阀门的相位延迟相加。 还必须添加控制器相位延迟。 在100HZ下延迟1毫秒是36度。

That is what I meant by the phase delay from the cylinder and load.

The phase delay for the cylinder and load is added to the phase delay of the valve at each frequency.  The controller phase delay must also be added.  A delay of 1 millisecond at 100HZ is 36 degrees.