Michael Vistein

The Robotics API: An object-oriented framework for modeling industrial robotics applications

During the last two decades, software development has evolved continuously into an engineering discipline with systematic use of methods and tools to model and implement software. For example, object-oriented analysis and design is structuring software models according to real-life objects of the problem domain and their relations. However, the industrial robotics domain is still dominated by old-style, imperative robot programming languages, making software development difficult and expensive. For this reason, we introduce the object-oriented Robotics Application Programming Interface (Robotics API) for developing software for industrial robotic applications. The Robotics API offers an abstract, extensible domain model and provides common functionality, which can be easily used by application developers. The advantages of the Robotics API are illustrated with an application example.

Hiding real-time: A new approach for the software development of industrial robots

The application of industrial robots is strongly limited by the use of old-style robot programming languages. Due to these languages, the development of robotic software is a complex and expensive task requiring technical expertise and time. Hence, the use of industrial robots is often not a question of technical feasibility but of economic efficiency. This paper introduces a new architectural approach making available modern concepts of software engineering for industrial robots. The core idea is to hide the real-time critical robot control from application developers. Instead, common functionality is provided by a generic and extensible application programming interface and can be easily used. Hence, this approach can lead to an industrialization of software development for industrial robotics.

Interfacing industrial robots using Realtime Primitives

Today, most industrial robots are interfaced using text-based programming languages. These languages offer the possibility to declare robotic-specific data types, to specify simple motions, and to interact with tools and sensors via I/O operations. While tailored to the underlying robot controller, they usually only offer a fixed and controller-specific set of possible instructions. The specification of complex motions, the synchronization of cooperating robots and the advanced use of sensors is often very difficult or not even feasible. To overcome these limitations, this paper presents a generic and extensible interface for industrial robots, the Realtime Primitives Interface, as part of a larger software architecture. It allows a flexible specification of complex control instructions and can facilitate the development of sustainable robot controllers. The advantages of this approach are illustrated with several examples.

Flexible and continuous execution of real-time critical robotic tasks

Today, industrial robots are usually programmed using specialised programming languages, different for every robot manufacturer. These languages provide good usability, because they are tailored to the functionality traditionally offered by robots. However, these languages are reaching their limits with the growing integration of sensors or multiple robot systems. Therefore, we propose an architecture based on the separation of application control and the execution of real-time robotic tasks. This article describes a flexible and extensible interface for the specification and continuous execution of robotic tasks.

An Abstract Specification Language for Static Program Analysis

Static program analysers typically come with a set of hard-coded checks, leaving little room for the user to add additional properties. In this work, we present a uniform approach to enable the specification of new static analysis checks in a concise manner. In particular, we present our GPSL/GXSL language to define new control flow checks. The language is closely related to CTL specifications that are combined with XPath queries. Moreover, we provide a number of specifications as implemented in our tool Goanna, and report on our experiences of adding new checks.

A backward-oriented approach for offline programming of complex manufacturing tasks

The automation of production processes with large process variability and a low batch size can be very difficult and non-economic. Using the example of manufacturing carbon-fibre-reinforced polymers (CFRP) which represents a complex, currently hardly automated process, we present a backward-oriented approach for offline programming of complex manufacturing tasks. We focus on an automatic process definition which is supported by expert knowledge where required. Due to domain specific software modules, user interaction is intuitive and tailored to CFRP experts. This leads to significant time-savings compared to currently used teach-in approaches. Moreover, we introduce an extensible offline programming platform which is able to meet the high requirements of CFRP manufacturing.

Managing extensibility and maintainability of industrial robotics software

As neither the set of robotics devices nor the operations they can execute is fixed, a software framework for robotics should be extensible. Moreover, as the environment the robots work in changes, the application controlling them must be easily adaptable to changing requirements. When this can be achieved at run-time, it leads to a continuous evolution of robotics software. This paper presents an object-oriented software framework, the Java-based Robotics API, that facilitates extensibility with code reuse. By integrating the framework into the dynamic module system OSGi, it is possible to continuously evolve a robotics application (including its real-time capable parts).

Instantaneous switching between real-time commands for continuous execution of complex robotic tasks

An application program for one or even several industrial robots usually consists of a number of disjoint commands, with each command controlling the robot to perform a certain task like motions or tool interactions. Sometimes it is desirable to be able to switch from one such command to another command with time guarantees for the switching progress, e.g. for blending one motion into another. In this paper we propose an approach to achieve this with two separate commands, where the second command can be created while the first is already being executed.

Towards Multi-functional Robot-based Automation Systems

Multi-functional robot cells will play an important role in smart factories of the future. Equipped with flexible toolings, teams of robots will be able to realize manufacturing processes with growing complexity. However, to efficiently support small batch sizes and a multitude of process variants, powerful software tools are required. This paper illustrates the challenges that developers face in multi-functional robot cells, using the example of CFRP production. The vision of a new programming environment for such future flexible automation systems is sketched.

On Structure and Distribution of Software for Mobile Manipulators

Complex robot applications or the cooperation of multiple mobile robots are use cases of increasing popularity where software distribution becomes important. When developing mobile robot systems and applications, software structure and distribution has to be considered on various levels, with effects on the organization and exchange of data. With respect to structure and distribution, this work proposes to distinguish between real-time level, system level and application level. Ways of structuring the software, as well as advantages and disadvantages of distribution on each level are analyzed. Moreover, examples are given how this structure and distribution can be realized in the robotics frameworks OROCOS, ROS and the Robotics API. The results are demonstrated using a case study of two cooperating KUKA youBots handing over a work-piece while in motion, which is shown both in simulation and in a real world setup.