Development and testing of load- and motion-decoupled actuator structures using nonlinear, model-based control algorithms

• Applicant: Professor Dr.-Ing. Jürgen Weber
• Subject Area: Engineering Design, Machine Elements, Product Development ; Automation, Mechatronics, Control Systems, Intelligent Technical Systems, Robotics
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 441872331

The aim is to develop and test robust independent metering control systems for efficient use in mobile work machines in terms of functional and economic industrial suitability. Current trends, such as automation and assistance yield in higher requirements for accuracy, controllability and operating characteristics of electro-hydraulic drives.A key challenge is the tuning of the control systems regarding energy efficiency, performance and robustness, especially under changing environmental variables. Using internal and cross-regeneration-modes, regenerative loads can be utilized and the primary power of the pump can be reduced. Due to process interactions and the complex kinematic structures of mobile machines, there are abrupt changes in load and speed. A soft transition between different recovery modes is the basis for an energy efficient machine operation.Using standardized, individual 2-way cartridge valve technology, instead of highly specialized directional valves, versatile potentials in terms of flexibility can be used on component as well as on system level. Seat valves with proportional characteristic allow volume flow control and additional functions such as load holding.Simulation based investigations provide information about requirements at component and functional level. Novel control concepts will be developed or existing methods from robotics can be adapted to the requirements of mobile construction machines. For this purpose, a two-step approach is proposed. First of all the algorithms will be developed and tested in a software in the loop environment (SiL) using a model of the virtual machine prototypes. In the second step, the developed algorithms are to be transferred and tested on a machine-level control hardware. The control device exchanges information with a real-time machine model in a hardware in the loop environment (HIL). The results of the simulation and development steps are transferred to the overall machine level. Finally an energetic and functional optimization of the overall machine system and its operating behaviour is conducted. After deriving appropriate criteria (performance indicators) a performance assessment is carried out.

• DFG Programme: Research Grants (Transfer Project)
• Application Partner: Liebherr Hydraulikbagger GmbH; Liebherr Machines Bulle SA