Goal-Oriented Control Systems (GOCS): Disturbance, Uncertainty and Constraints

Control systems play a central role in automation and modern industry. By using feedback, control systems are designed to regulate system outputs around a reference setpoint or track a reference trajectory, despite disturbances and variations due to its operational environment; for example, an aircraft follows a specified speed and altitude despite gust, wind and changes typical of an aircraft (e.g. number of passengers). Performance specifications for control systems are typically defined to quantify their behaviours in terms of the defined reference. The analysis and design tools/methods across the entire area of control engineering are mainly developed and built upon these specifications. With the demand for ever increasing levels of automation, we are moving towards goal-oriented operation, where what a system needs to achieve is specified at a high level (e.g. in terms of economic or mission requirements), rather than how it is to be achieved (e.g. through defining a setpoint or trajectory). The goal-oriented operation improves the operation process, offers new opportunities for technological advances and reduces operational costs. A Goal-Oriented Control System (GOCS) is essential to enable this type of operation. Another significant difference in GOCS is the influence of disturbance/uncertainties on design specifications. Traditionally a central role of a control system is to attenuate the influence of external disturbance/uncertainties because they always divert the system away from a reference. However, certain disturbance may be good for the system operation in terms of a high-level goal. For example, changes in raw material or environment may make a chemical process more profitable so they should not be rejected; a favourable change of wind condition should be exploited, rather than rejected in an emergency landing as it helps the aircraft to glide longer, providing a larger safe margin in performing forced landing.
In current control system design, constraints (e.g. physical, operational, legal) are often considered explicitly or implicitly through generating appropriate references. However, as the system specifications will be defined at a high level in goal-oriented operation and the control system must work out how to achieve the specifications/goals, constraints must be specified very carefully in order to meet safety and other requirements. Some constraints are difficult to represent in the specifications or to take into account constraints within current control design.

This Fellowship will develop analysis and design tools for goal-oriented control systems, build up a unified framework for the next generation of control systems in performance specifications, constraint representation and problem formulating, investigate its performance and other properties in the presence of disturbance, uncertainties and constraints, and benchmark their applications. Temporal logic will be used to represent high level specifications and a wide range of complex constraints. By combining temporal logic with rich representation of dynamic systems in control engineering, it aims to develop a complete new analysis and design framework for GOCS that involves both rich dynamics and complex specifications in performance and constraints, and to provide analysis tools for the propagation of information errors, environmental disturbances and dynamic uncertainties into the high level performance specifications and fulfilment of constraints, and the interplay of these terms with a feedback strategy and controlled dynamics. The Fellowship programme is developed and built upon the Fellow's internationally leading work in disturbance observer-based control, model predictive control and autonomous vehicles in the last 25 years. The successful completion of the Fellowship will open a new field of goal-oriented control systems, transform control engineering and unlock the potential of moving from low levels to high levels of automation

Economy
Goal-oriented operation is regarded widely as the next step within Control Engineering for a wide range of applications across industrial sectors (aerospace, automotive, chemical engineering, manufacture and healthcare). It opens many new opportunities: increasing levels of automation; allowing the specification of a high-level goal and taking advantage of new opportunities (e.g. the favourable changes of environment and operation condition). Therefore, it brings enormous opportunities for improving efficiency, productivity, safety, and reliability, and creating new products and services that are impossible without high level of automation (e.g. driverless cars, drone, automated healthcare for elderly people living at home, farming automation). Fellowship outcomes will help to increase UK competitiveness across industrial sectors. The knowledge and skills of analysis and design of goal-oriented control systems are largely transferable across application domains. The UK government has identified four Grand Challenges in its Industrial Strategy: AI and Data; Ageing Society; Clean Growth; and Future of Mobility. It is obvious that goal-oriented operation relates and contributes to all of them.

Society
Our society is facing a number of global challenges (e.g. food security, climate changes). It is crucial for the UK to contribute and even take a leading role in addressing these challenges for humanity and our planet. Information enabled high level automation advocated in this proposal would contribute to addressing many challenges; for example, food security (e.g. remote sensing enabled automatic treatment, precision agriculture), and affordable, reliable, sustainable energy (e.g. smart microgrid). The societal impact is illustrated by the Fellowship's selected case studies. In the automatic search for hazard substance release, the control system not only keeps the first responders out of harm but also reduces the risk to the public by quickly finding sources of contamination. It is also important for environmental protection. The autonomous driving case study aims to develop performance guaranteed autonomous vehicles that can achieve high level specified goals under all the disturbances, environment uncertainties and (physical and legal) constraints with properties rigorously established by the analysis and design tools developed in this proposal. This would significantly improve the level of safety in deploying them in a public environment.

Knowledge
A framework and a significant amount of new knowledge about goal-oriented control systems will be generated including their applicability, limits and the insights between different types of design methodology and their relationships with other relevant methods. The research agenda of goal-oriented control systems will be put forward at the end of the Fellowship, which will transform future research directions in control engineering, computer science and applications domains where automation is beneficial (e.g. automotive, aerospace, electrical, energy).

People
PhDs and RAs working on this project will benefit from its interdisciplinary nature, working at the interface of control, computation, information and dynamics. Researchers will gain skills in, for instance, optimisation based control, hybrid dynamic systems and multilayer systems, and a deep understanding of their research area combined with a broad understanding of the context in which their research sits. The Fellowship will further equip the team with new skills in coping with challenges arising in an ever connected world. Crucially the Programme would develop a pipeline of highly-skilled young researchers working on the next generation of control systems. New concepts and use cases developed in this research would be incorporated into teaching materials in both MSc and undergraduate teaching.