In this paper, we propose an on-board diagnosis method for the embedded system based on the model-based diagnosis. We introduce the qualitative model for the embedded system by transforming the continuous dynamics of components into the discrete state transition system which is represented in the circuit called a synchronous Boolean tree (SBT). The SBT is a network of the (temporal) propositional operations with latches. The faults of components are reduced to the stuck-at faults in SBT. We present a many-value tableau method for the SBT diagnosis, which allows the efficient search for the faulty parts by propagating the observed anomaly through the SBT.
This paper introduces a modeling and design for opening-and-closing speed control of an elevator door using ILQ design method with frequency-shaping function (FSILQ). A door opening-and-closing control system is designed by applying this method to a very low order reduced model. High performance of the resulting control system is obtained through proper modeling, simulation and repetitive experiments. It is confirmed that an inevitable vibration of the door speed due to model uncertainty can be suppressed by proper shaping of the frequency response of the closed loop transfer function from noise to output. The resulting control system is evaluated by applying ramp inputs as well as step inputs. As a result, the proposed control system has been verified to show robustness for a wide range of weight of door panels.
We participated in NTCIR QAC-1, QAC-2, and QAC-3, which were evaluation workshops for answering questions held by the National Institute of Informatics of Japan and studied question-answering systems for contextual questions. Contextual questions are defined as a series of questions with contexts. For example, the first question is “What is the capital of Japan?” and the one succeeding is related to the first such as “What was it called in ancient times?”. Contextual question-answering can be considered interactive. This paper describes our system for contextual questions. Our question-answering system used numerous effective methods to answer questions. We used a method of connecting question sentences to handle contextual questions. We also used a method of using multiple documents to obtain more accurate answers. We confirmed that these methods were effective in the experiments. Our question-answering system obtained the second best accuracy in QAC-1 and the best accuracy in both QAC-2 and QAC-3 for contextual question answering. It is thus a high-performance system.
A data-driven model-free design method of PID gains based on falsification is examined for a mixed sensitivity control problem. The PID gains that do not satisfy the specification can be falsified effectively by using many sinusoidal responses by our previous method, but they are not falsified well by a single response. Therefore, it requires many experiments in order to obtain good results. In this paper, we propose to generate a set of fictitious responses by filtering a single response with many bandpass filters, and to use them for falsification. The PID gains can be falsified effectively by this new method.