Test Rigs and Components

Hexapod Hex-25-85

FGB produces hexapods to individual specifications that allow the user to subject parts and components with realistic multiaxial loads. Thanks to the customised approach, test benches are created that are ideally suited for the respective application purpose.

The latest machine of the hexapod series by FGB now allows chassis components to be tested under realistic application conditions for the first time but with much less effort than previously. Using these highly dynamic, servo-hydraulic test benches, it is possible to reduce test times and costs compared to other methods.

X: ± 55mm, Y: ± 55mm. Z: ± 85mm

± 18 °

± 25 kN

± 9 kN

± 9 kN

X: 2,5 kNm, Y: 2,5 kNm, Z: 1,3 kNm

max. 1,9 m/s

170 m/s²

0 Hz bis 70 Hz

350 ltr./min, - 280 bar.

The requirements made of the test bench are enormous: Absolute dynamics in the shape of 17-fold gravity and extreme system precision and rigidity pose known challenges that need to be taken into account when developing hexapods. When developing and constructing these kinds of test benches, FGB falls back onto supplementary test bench equipment from our own product portfolio. For instance, the connection unit, ball joints and the error-free control are in-house developments.

Special cardan foot joints supply fully hydrostatic cylinder with oil without hoses. This means that the cylinders are not affected by the interfering hose pulsations nor the hose drag; also, the cylinders are prevented from swinging around their piston rod axis. This also allows the inertia influence of the cylinder mass to be kept low, because they can be installed close to the pivot point of the foot joint thanks to the compact cylinder joint design.

The hexapod can be operated in a force and path-regulated manner and allows impact-free switching between operating modes.

The test machine contains a hybrid force/path decoupling control so that the user can define path or force specifications for the test in every room direction of a freely definable test body coordinate system. Implementation on the individual hydraulic cylinder is carried out in the software without the user having to intervene.

The function software MOSA-Control realises the iterative duplication control, the non-linear iterative duplication control and operation of the test bench in the Pseudo-Force-Control mode. All signals refer to the test body coordinate systems defined in the basic software.


Alexandra Wierzba

phone: +49 (0) 9771 68877-584