HORSE Prototype System
The HORSE prottype system implements the HORSE framework. It covers dynamic actor allocation to work cells, direct robot control and human actor instruction, closed-loop local event processing and near-real-time global event processing. It specifies the operational deployment of a cyber-physical system that adopts the framework in manufacturing production lines. The HORSE framework consists of several software components that can be grouped into three main groups: the core components, the interfaces, and the case-specific ones (see HFW supporting document. The first group contains the cyber components responsible for management of the whole manufacturing process, the MPMS – Manufacturing Process Management System and for execution of tasks in the work cell, the HTS - Hybrid Task Supervisor. They can be successfully used regardless of the actual scope of the use case. The interfaces contain both the HORSE middleware, which is essential to communication between the components of the framework, and the interfaces connecting the framework to other systems e.g. the Bosch infrastructure or ROS components. Finally, the case-specific components provide functionalities required by concrete applications. Those may involve robot control, trajectory planning, augmented reality etc. Their development is usually driven by a specific use-case; however, they can be adapted to similar scenarios with minimal effort.
Therefore, each HORSE deployment includes the MPMS (level 3) and the middleware (level 2). The first one is necessary to define, execute and monitor the process. The second one, the middleware provides communication capabilities for the heterogeneous components of the framework. Depending on the realized scenario the HTS can be also used to trigger and synchronize tasks on the level of individual work cells.
The case specific components may be adapted and used in different scenarios if they fit the requirements. Although reusing the existing software is strongly recommended, new components can be integrated as well, as long as they are connected to the messaging middleware of HORSE.
At the bottom of the HORSE functional hierarchy, that is built on the IEC functional hierarchy (which is another industry standard that we adopted like RAMI), lay the agents that execute the production tasks being any kind of maching (robotic arms, AGVs or other production machinery, sensors and things that are necessary for controlling and monitoring the production and humans).
HORSE functional hierarchy
More detailed description of the HORSE Prototype System
High level description of the system
The design, enactment and monitoring of manufacturing processes is realized by a Manufacturing Process Management System (MPMS), based on typical Business Process Management Systems (BPMS, mostly applied in the administrative domain). The MPMS covers the global functionality of the HORSE system. The abstraction layers are realized with a cyber-physical middleware, necessary to connect all different technologies. The Hybrid Task Supervisor (HTS) software is responsible for designing the detailed steps of a manufacturing task (covering the design phase) and synchronizing the activities of the agents of the team that perform the task.
These three software systems are the backbone of the HORSE system, able to support the manufacturing operations in an enterprise.
The Manufacturing Process Management System (MPMS) covers the global design and global execution layers of the HORSE logical architecture (see the below figure). Its functionalities are:
- the design of process and agent models,
- orchestrating the global execution of the manufacturing process by selecting the next task in the process to be executed for an order, selecting the right agent(s) to perform this task, and delevering work items to the worklist of these agents
- monitoring production execution.
Such a system was realized in the HORSE project as an extension of Camunda BPM, an open-source workflow management platform.
Database Management software is used for implementation of the data stores of the architecture (Process/Agent Data). In HORSE we used PostgreSQL Server, it can be any other database system.
Middleware to connect the various systems of HORSE
In HORSE, a Websocket-based message bus was used based on the OSGi (Open Services Gateway initiative) specification. OSGi is a modular system architecture and a service platform for the Java programming language that implements a complete and dynamic component model for general module interconnection. It also provides a universal publish-subscribe messaging bus for communication among system modules. Furthermore, tailored-made OSGi Applications can be used, as software packages that offer powerful and sophisticated component management and interoperability, as well as context-aware assistance of agents (workers, robots) on the production floor in the execution of their tasks.
Hybrid Task Supervisor software
The role of such a software is to configure and synchronize execution steps by agents. Typically, state machines can offer the detailed execution of robotic steps. FlexBE is such a system and was used in HORSE project. It features OSGi plugins to existing OSGi nodes, ROS (Robot Operating System) integration to robots and interfaces to industrial equipment.
Hardware interface software
The Robot Operating System (ROS) is a commonly used, open-source, meta-operating system for robots and provides functionality such as hardware abstraction, low-level device control, implementation of commonly used functionality, message-passing between processes, and package management. Within ROS environment, several applications can be used: ROS MoveIt! for force feedback control to enable more precise handling (gripping, placing, etc.) of objects; ROS Kinetic for simple operating system functionality and the interfacing between the above mentioned ROS applications and the robot. These were used in HORSE as well.
- Technology-specific robotics interfaces. Depending on the type and brand of robots that a manufacturing organization utilizes, various5 software platforms can be used for hardware interfacing.
- OPC UA is used as the interface to advertise and invoke robotic services.
- Other software packages that are normally used in manufacturing environments with advanced robots are: software for advanced robot motion planning6. To provide the processing power required by such software, a parallel computing platform and application programming interface model is required. Such a high-performance processing platforms enables real-time 3D projections.
- Software to support augmented reality.
The Hardware (bottom) layer is composed of :
- Robotics in various forms, ranging from multi-axial arms to collaborative robotics, also referred to as cobots.
- Autonomous guided vehicles (AGV) that can transport materials, products and tools in and around the factory, without human intervention.
- Handheld devices, such as smartphones, to provide information to the operator and allow for tracking of manufacturing tasks performed by humans.
- Operator augmentation devices, such as virtual reality devices, to provide information to the operator in a topical and interactable manner.
- Other automated (non-configurable) devices, such as conveyor belts, which (horizontally) transport products
- Sensors, measuring temperature, weight, etc, and cameras
- Computers, that host of all the software modules to run a CPS.
Technical characteristics of HORSE Framework
The HORSE Framework promotes a modular solution with clearly defined functional elements and interfaces. The key characteristics of HORSE framework of interest to developers, integrators and service providers are:
Clear interfaces that allow replacement of modules and integration of new ones:
- OSGi plugins to the existing OSGi nodes;
- New ROS components;
- Modules based on other technologies;
A scalable messaging middleware that
- is based on a widely accepted communication protocol (WebSocket)
- is exchanging well-structured JSON formatted messages
- permits encryption of the payload or the entire communication channel
- offers reusable components (messaging agents) in Java (OSGi) and Python
- features bridges to ROS and OSGi
- supports prioritisation of the messages
- Web services standards simplifies integration to manufacturing technology, making the HORSE System suitable for factories with existing and heterogeneous robotic solutions.
HORSE Framework Prototype system value for SMEs
The HORSE framework addresses SMEs challenges in an integrated way. HORSE covers both the global level of manufacturing processes (at the factory or production line level) and the local level of individual manufacturing activities (within specific work cells). It addresses both the set-up of processes and functions at these levels, and the real-time execution of processes and activities.
|HORSE framework is customizable and modular; not only it provides important tools which can be adapted to the specific needs of each SME, but new and legacy hardware and software is able to be integrated and used within the framework.|
The principles of flexibility and standardisation provide the following benefits:
- HORSE framework enables and simplifies adoption of robotic manufacturing solutions for SMEs.
- Compliance with international standards and best practices notation (RAMI, OSGi, ROS, OPC-UA, etc. ) ensures applicability to any discrete or batch production facility.
- The modular design supports adaptation to different situations and a variety of challenges faced by manufacturing industry SMEs – not every SME context requires the full HORSE framework; production resources can easily be added, deleted or updated.
- Seamless integration between HORSE System modules and openness to external technology (such as robotic platforms and sensors) makes Industry 4.0 technologies removes development barriers and reduces relative costs.
- The explicit manufacturing process management approach (at the global level of the HORSE System) allows for high levels of flexibility in manufacturing process design, thereby opening ways for easy re-use of manufacturing activities and underlying manufacturing infrastructure, and evolution towards mass-customization of products.
- The dynamic allocation of production resources (such as workers and robots) in manufacturing processes is a strong basis for improved process efficiency, leading to shorter throughput times of manufacturing processes and higher resource utilization.
- The provided high-level overview of the status of the manufacturing process at the production line level and manufacturing activities at the work cell level ensures that the operational management of manufacturing facilities has an up-to-date view of the real-time status of businesses.