Tallinn University of Technology

Human-Cyber-Physical Systems or Cyber-Physical-Social Systems

The research focus of Research Laboratory for Proactive Technologies (ProLab) has traditionally been on proactive Real-time systems. Some years ago we have extended the focus so that it covers Human-Cyber-Physical Systems (H-CPS). Proactive real-time systems form an important subset of H-CPS.
H-CPS result from reinforcing physical and social processes (and/or systems) with cyber capability of computation and networking. The behavioural complexity of H-CPS is caused by (relative) autonomy of separate component systems, multiple temporal, spatial, and social constraints, unavoidable and persistent dynamic reorganisation, and required high dependability.
Researchers and designers of H-CPS attempt to mitigate behavioural complexity of H-CPS by inserting self-X properties – e.g. self-organisation, self-healing, and self-protection. Self-X properties assume the ability of run-time behaviour verification after each serious modification of the system – in order to check the integrity of the system and that the system still operates within its safety and security envelope. From mathematical point of view such systems lead to ill-posed problems renowned from attempts to control objects with time-variable structure.
We interpret proactivity as ability to initiate non-trivial changes in system’s behaviour. Proactivity can be contrasted to conventionally used term “adaptivity” that means system’s ability to respond to non-major changes in its environment. Proactivity expands the notion of proficiency to cover/manage major unpredictable requirements.

Hence, proactivity is about being anticipatory and taking care of dynamically occurring (not necessarily a priori predicted) situations. A proactive system acts to influence the joint evolution of the system itself and its environment, in order to improve the satisfaction of system’s goal functions rather than just reacts to (a priori defined) detected situations in the environment.