Delay‐incorporating observability and predictability analysis of safety‐critical continuous‐time systems

Abstract

The authors suggest a framework for human-automation interaction in safety-critical continuous systems under shared control and consider continuous-time linear time-invariant (LTI) dynamics to formalise our physical models mathematically. Their goal is to determine whether or not a given user-interface provides the information required for a certain task, under the assumption that the user does not have access to any information beyond what is provided in the display. They identify observability-based conditions under which a user-interface provides the user with necessary information to accomplish a given task, formulated as a subset of the state space. They, therefore formulate the novel delay-incorporating user-observable subspace, and the delay-incorporating user-predictable subspace and compare them with the space spanned by the combination of the states which create the task. They assume the user is a special type of observer, with capabilities corresponding to different levels of knowledge regarding the current user's input and its derivatives. In addition, they consider that state reconstruction and prediction incorporate a processing delay. IntroductionAs interfaces and their underlying systems become more complex, information beyond what is contained in the interface may not be accessible. We aim to identify tools that assess the correctness of a user-interface for a given task, an especially relevant problem in systems for which intuition and simulation may not be enough to assure that an interface is effective. While in many systems, such as a human-driven car, the user has access to information beyond what is simply contained in the interface, we focus here solely on information contained in the interface, for example, a remotely controlled car or a pilot performing a task in high altitude.Human-factors researchers have frequently pointed out the importance of incorporating human-factors into traditional control theory, which can result in better human-automation interaction [1, 2]. Many researchers have suggested frameworks for humanautomation interaction in order to come up with more effective interaction between the elements of the system [1-3]. Attaining situation awareness (SA) is a human-factor concept which is known to be necessary for the user to have correct interaction with the automation [4,5]. Attaining SA includes three levels of processing the information, (i) perception of the information, (ii) comprehension of the information and (iii) projection or prediction of the information [4,6]. Lack of SA can lead to a faulty control action by the operator because of bad decisions. As we have already assumed that the display is the only source of information for the user, it has to be designed to allow the user perceive, comprehend and predict the desired information to attain correct SA. Hence, the display design procedure requires a careful selection and clear presentation of the information for the user to perform the desired tasks correctly.Some examples which are available in the literatu...

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“…The block of the closed-loop system under shared control by et al [53]. updated policy A Vision for Safety in 2017 [62]: it encourages regularization entities on the definition and documentation of Operational Design Domains (ODD) for each automated driving system of the vehicle.…”

“…A new model is proposed by combining the model of the classical control theory block diagram of Kleinman et al [47] with the SA-based block diagram of Eskandari et al [53], as shown in Fig. 4.…”

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