Trust between Cooperating Technical Systems
Walter Bamberger · mediaTUM – the media and publications repository of the Technical University Munich (Technical University Munich) · 2014
Researchers from the social sciences and economics consider trust a requirement for successful cooperation between people.It helps to judge the risk in situations, in which a person has the choice to rely on another one.In the future, technical systems will face similar situations.Assume for example that, at a large logistics centre, a robot should reload goods of a ship in cooperation.In the beginning, it must find the right partner out of a set of diverse other robots.To do this selection efficiently without exaggerated security mechanisms, the robot needs trust.Here I consider trust a mechanism, which estimates the certainty of the outcome of the partner's actions.This dissertation formalises trust between technical systems to set the theoretical foundation for the above idea.It reviews the socio-scientific and technical literature and identifies generic requirements for the mechanism trust.Based on the requirements and further considerations, it presents a conceptual, implementation-independent framework.This new framework, called the Enfident Model, incorporates various facets of trust in form of submodels.Amongst others, it regards the temporal development of cooperation, the dependency on the task and bargaining, time-varying behaviour of the cooperation partner, learning from experiences, logical constraints of the present situation, and transfer learning to handle unknown situations.With these manifold features described on a conceptual level, the Enfident Model captures existing trust procedures and is suitable for designing new ones.The theoretical part is complemented with algorithms for prototyping trust in individual applications.These algorithms use statistical relational learning to combine logic, learning, clustering and statistics for trust development.They work on a relational dynamic Bayesian network.Since trust is a social phenomenon, the evaluation features a virtual society of vehicles.These systems cooperate by exchanging information in a vehicular network.They use a trust algorithm to distinguish correct from incorrect information.The simulation shows that the identified trust requirements and the Enfident Model lead to intuitive and consistent results.Competence: p(O)p * (O) Expertise:O performs his tasks perfectly.O has the skills important for that task.Justice:O pays attention to laws and moral principles.Prototype-ness:O represents the group as a whole.Consistency: p(O)p s (O)Predictability, dependability: O behaves as he did before in similar situations.O behaves reliably and uniformly.Honesty, integrity:O speaks as he really thinks.Promise fulfilment:O does what he promises.Discreetness:O can keep confidences. Similarity: p(P)p(O)O has the same goals or moral values as I have. Empathy: p(o(P))p(P)Understanding: O sees me as I am.Receptivity:O understands my ideas.Acceptance: p(o(P))p(O)O takes me as I am and stands by me.Benevolence:O can relate myself positively to himself.Loyalty:O protects me