FGB produces hexapods to individual specifications that allow the user to subject parts and components with realistic multiaxial loads. Due to the customised design, test benches are created that are ideally suited for the respective application purpose.
The concept presented here interprets the FGB hexapod topic in a completely new way. This allows us to meet the increasingly stringent dynamics and flexibility requirements – without compromising on accuracy – as best as possible. In principle, the hexapod is suitable for various test scenarios with 6 levels of freedom.
Platform paths: [X,Y,Z]
Z ± 150 mm, X± 150 mm, Y ± 150 mm
Platform angle: [X,Y,Z]
Single force on the platform: [Z]
Single force on the platform: [X]
Single force on the platform: [Y]
Single torques on the platform: [MX,MY,MZ]
ca. 40 kNm
Platform speed: [Z] continuous excitation / sine
Platform speed: [Z] briefly via store / sine
Platform acceleration: [Z] briefly via store / sine
Work frequency max:
0 – 30 Hz
Pressure oil supply:
750 ltr./min. – 280 bar
Path / force
To meet the high requirements relating to dynamics coupled with optimum overall rigidity and the lowest possible inertia of the hexapod system, FGB has developed special cardanic foot joints that supply the 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 high-performance standard of our hexapods is the result of the innovative details of the test bench.
The hexapod can be operated in a force and path-regulated manner and allows impact-free switching between operating modes. Also, the extensive test software package contains an iterative control mode in which heavily non-linear material behaviour is considered.
The hexapod 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.