US 12,392,683 B2
Safety apparatus for one degree of freedom electrodynamic shaker
James Q. Zhuge, Palo Alto, CA (US); Michael Nichols, Charlotte, NC (US); and Weijie Zhao, Los Gatos, CA (US)
Assigned to Sentek Dynamics Inc., Santa Clara, CA (US)
Filed by Sentek Dynamics Inc., Santa Clara, CA (US)
Filed on Jul. 13, 2023, as Appl. No. 18/221,827.
Prior Publication US 2025/0020536 A1, Jan. 16, 2025
Int. Cl. G01M 7/02 (2006.01); G01B 11/26 (2006.01)
CPC G01M 7/022 (2013.01) [G01B 11/26 (2013.01); G01B 2210/58 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A safety system for a single axis electrodynamic shaker having an armature designed for variable amounts of vibration with a single degree of freedom movement along an axis comprising:
a control loop including a support table and test unit connected to the shaker armature, a controller generating a drive signal to the shaker adjusting shaker vibration, an amplifier connected to receive the drive signal for exciting the shaker upon amplification, the controller receiving an input from the shaker representing shaker vibrational motion;
a plurality of displacement sensors outside of the control loop and remote from the support table and test unit, the sensors measuring dynamic linear displacement quantities of the test unit and reporting displacements and their derived quantities to the controller;
a detection signalling mechanism in the controller to compare if the displacements or their derived quantities are over the preset limits based upon displacement quantities reported from the sensors; and
an alarming or shutdown mechanism to ramp down the drive signal of the controller based on the detection signal.