Multi-loop testing controls two or more shakers on a single axis or multiple ones. Each output drives a separate shaker to more closely replicate the operational environment. Three-axis, four-post, and dual-shakers are examples of multi-loop testing.
Download Demo All Software ModulesMulti-loop control refers to a vibration test setup with multiple shakers running on the same axis or different axes. There are many ways to configure a multi-loop vibration test. The two key characteristics of a configuration are the number of shakers and the number of axes/degrees of freedom.
A multi-loop test requires one VR9500 per control loop or a VR10500 with multiple loops enabled. Each VR9500 requires the necessary VibrationVIEW software and includes one method of control. The primary VR10500 controller must drive all outputs, but the system can have stacked controllers for more than 16 inputs (up to 512).
The Sine, Random, Shock, and Field Data Replication (FDR) test modes can run 2, 3, or 4 output drive loops simultaneously, but they have different control capabilities on the VR10500.
Run a vibration test in the three linear directions simultaneously.
Three-axis testing performs vibration control on a triaxial shaker using identical or individualized test profiles. The VibrationVIEW software supports different profiles for random vibration tests, and the test systems are compatible with all servo-hydraulic and electrodynamic shakers.
3-axis Control
Synchronize two shakers with the same test profile.
Dual-loop phase control synchronizes two shakers moving on the same axis while maintaining phase through level changes. It uses 2 outputs of a VR10500; the drive and COLA outputs from one controller drive multiple shakers with the same test profile. The result is a synchronized set of shakers, ideal for full system testing of a larger device.
Dual Loop Phase Control
Control four shakers moving along the same axis.
A four-post test employs multi-loop control on four shakers moving along the same axis. Engineers often run these tests on complete vehicles. They place a shaker under each wheel and play back four field recordings from each wheel. Then, the recorded vibrations are played back simultaneously as if the vehicle was in motion.
Four-post Control
