Abstracts of Invited Talks

Prof. Reinhard Wilhelm (Saarland University, Germany)

Toward Compact Abstractions for Processor Pipelines

Hard real-time systems require programs to react on time. Static timing analysis derives timing guarantees by analyzing the behavior of programs running on the underlying execution platform. Efficient abstractions have been found for the analysis of caches. Unfortunately, this is not the case for the analysis of processor pipelines. Pipeline analysis typically uses an expensive powerset domain of concrete pipeline states. Therefore, pipeline analysis is the most complex part of timing analysis. We propose a compact abstract domain for pipeline analysis. This pipeline analysis determines the minimal progress of instructions in the program through the pipeline.


Prof. Wolfgang Schröder-Preikschat (Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU))

Predictability Issues in Operating Systems

Predictability is always subject to the underlying assumptions being made. For real-time systems, time response of processes in relation to the strictness of deadlines is of particular importance. With an additional focus on embedded systems, space and energy requirements become relevant as well and need to be considered in combination. As far as software is concerned, structure and organisation of the programs to be executed determines whether or not predictable processes will take place in a given computing system. Design for predictability is an overarching aspect that crosscuts the whole computing system and particularly addresses operating systems.

This talk is about structuring principles of non-sequential programs - in the shape of but not limited to operating systems - to abet predetermination of quality attributes of non-sequential (real-time) processes, it is not about analytical methods to effectively predetermine these attributes. Issues in operating systems as to space, timing, and energy requirement are touched. Emphasis thereby is on coordination of cooperation and competition between processes, namely synchronisation. It is shown how measures of process synchronisation against the background of many-core processors cater to these issues.


Prof. Gerhard Rigoll (TU München, Germany)

Augmented Reality User Interfaces

This presentation describes a novel generation of user interfaces for control of machines, or other complex technical systems such as robots or plants. So far, typical user interfaces for such systems consisted of a classical monitor with a surface controlled by mouse and keyboard, where recently the interaction paradigm has changed from direct manipulation via mouse to touch gestures, similar to typical smartphones.

Augmented reality user interfaces have emerged from tow recent developments: The first one is the fact that more an more smartphones are replacing stationary control devices, e.g. for the control of electronic consumer devices or drones or others. The second is the fact that the area of augmented reality (AR) has changed from displaying the digital content in head mounted displays to mobile AR, where the camera of the mobile device captures the environment on the screen which is then augmented with additional virtual objects. Such an interface is much more powerful for controlling complex systems and the talk will especially emphasize the possibilities for interacting with such AR-devices. The final part of the talk will present such interfaces in the framework of Augmented Reality Videoconferences, where users collaborate over distance using interfaces where e.g. shared documents are displayed as AR objects which can be jointly manipulated by multiple users. Here, the user himself can be displayed as 3D-AR projection into the space of the remote user, which involves the usage of image an pattern recognition technologies, such as pose tracking or processing of 3D point clouds.

Prof. Sharon Hu (University of Notre Dame, Indiana, USA)

Resource Management in Cyber-Physical Systems

A cyber-physical system (CPS) is a system built from close integration of computational fabrics and physical components. Examples of such systems include avionic systems, industrial control and civil infrastructure monitoring. In a CPS, sensors and actuators are used to monitor and control the physical components while the computational fabrics determine the control values for the actuators based on the sensed data. All CPSs require timely delivery of both information from sensors to the computing fabrics and control signals from the computing fabrics to actuators. Managing the limited resources (e.g., computation power and communication bandwidth) to meet the timing requirements in a CPS is a challenging task. Even more challenging is that CPSs should degrade gracefully in the presence of various external disturbances such as failure in critical civil infrastructures and malicious attacks.

In this talk, after a briefly introduction of the general CPS concept, I discuss several Quality of Service (QoS) metrics for CPSs, the challenges they present to resource management, and some high-level ideas to tackle the challenge. I then focus on one specific problem where a CPS system implemented as a wireless networked control system must deal with unexpected external disturbances. Due to the limited bandwidth in the system, some packets may have to be dropped. I show how a dynamic data-link layer schedule can be constructed to minimize the number of dropped packets while meeting the desired QoS.