Plug-and-Produce: Demonstrator Platform for Decentralized and Interoperable Fluid Power Components
Current trends in manufacturing, such as mass customization, shortening of product life cycles, efficient maintenance, higher functionality and reliability of machines, all result in an increasing complexity of automation lines and the demand for frequent reconfigurations. This high versatility poses the requirement for interoperable components and self-organizing fluid power systems. A proof of feasability of such “Plug-and-Produce” solutions is realized on a demonstrator platform for a pneumatic and a hydraulic reference system, respectively.
Setup of the Demontration Platform
The pneumatic reference system represents a handling system, which comprises a valve terminal, pneumatic cylinders for multi-axial movement and a gripper for picking and placing objects. Moreover, a mass flow sensor, pressure sensors and limit switches provide sensory information. The hydraulic reference system represents a linear hydraulic system consisting of a hydraulic aggregate for the power supply, as well as a 4/3-way directional control valve for controlling a hydraulic cylinder. A second hydraulic cylinder is used to provide a load force for the main cylinder. The state of the hydraulic system is observed by pressure and position sensors. For both reference systems, functional units are defined which combine active and passive components to manageable units, while components are easily accessible and exchangeable. Furthermore, each functional unit is each equipped with single-board-computers to provide connectivity and edge computing capabilities.
Forming IIoT-Components
In contrast to classical systems, which are organized in hierarchical and centralized structures, decentralized systems consist of loosely coupled collaborating IIoT components. Individual components offer encapsulated functionalities (services), which can easily be used by other system participants to solve tasks in a flexible way. These IIoT-components, consists of the real object and a corresponding virtual representation. The latter comprises aspects of self-description, services and basic communication and consequently enables interoperability. A concept that covers these aspects of consistent virtual representation is the Asset Administration Shell (AAS). By use of standards for self-description and service-oriented implementation of functions, AASs are generated for each functional unit in the reference systems in order to act as interface for the coordination of joint tasks.
Automated commissioning in a Distributed System
On the basis of the IIoT components an assisted and, where possible, fully automated commissioning process could be developed. Semantic information and interaction models allow the participants in the distributed system to gather information on adjacent components and on the overall system they are embedded in. Using the commissioning steps and requirements incorporated in the AAS of each functional unit, a commissioning sequence can be automatically derived for the distributed system. Finally, the autmated comissioning allows for a more efficient and fault free reconfiguration which, in addition, is independent from the experience of the operator.