O v e r v i e w
A newly designed aircraft must be thoroughly tested before it can be flown. Hydraulic stress testing is a common technique for checking the strength and flexibility of wings, fuselage, propellers, and entire airframes. Tens or even hundreds of hydraulic actuators push and pull at an airframe to test for failures and materials fatigue that might occur under flight conditions. Strain is measured at hundreds of points to qualify test results.
P r o b l e m
To simulate actual test conditions, each actuator must be controlled independently yet synchronously with all of the other actuators. Actuator force must be updated many times per second to simulate dives and turns. To avoid destroying expensive prototypes, limit checks must be used to cut power to the actuators in case force or travel maximums are exceeded.
O v e r v i e w
Automobiles, trucks and railroadengines require on-road testing to verify their design. Characterizing a variety of parameters can lead to better and more efficient vehicles. Often the electronic circuitry used to control the engine can be improved for better economy.
P r o b l e m
A mobile system with high reliability is needed to withstand road test conditions and still provide accurate measurements. Electronic noise introduced by the operating vehicle must not adversely affect measurements. Large amounts of data must be stored for subsequent analysis in the lab.