The Monte Carlo Approach to State Estimation for Linear Dynamical Systems with State-Dependent Measurement Noise

This paper is concerned with the state estimation of linear dynamical systems with state-dependent measurement noise. The minimum variance estimate of the state is obtained as the weighted mean of the outputs of Kalman filters parameterized by the state-dependent measurement noise sequences. The usual calculation for this estimate, however, becomes impractical since a very large amount of outputs of Kalman filters is required. Therefore, we regard the set of all the state-dependent measurement noise sequences as a population. Then, we evaluate the minimum variance estimate on the basis of a relatively small number of outputs of Kalman filters, parameterized by the state-dependent measurement noise sequences sampled at random from the population. The convergence of the algorithm is established. Then, by an approximation of a sampling procedure with a fast convergence property, a feasible sampling procedure is determined and a practical algorithm is designed. This policy of design leads to an efficient algorithm. Digital simulation results show a good performance of the proposed algorithm

スイテイオヨビセイギョモンダイニタイスルモンテカルロホウテキアプローチ

京都大学0048新制・課程博士工学博士甲第1746号工博第459号新制||工||343(附属図書館)4837UT51-51-K19京都大学大学院工学研究科精密工学専攻(主査)教授 明石 一, 教授 清野 武, 教授 岩井 壮介学位規則第5条第1項該当Kyoto UniversityDA

Fault-tolerant automobile steering based on diversity of steer-by-wire, braking and acceleration

Steer-by-wire (SBW) systems, which have no mechanical linkage between the steering wheel and front wheels, are expected to improve vehicle safety through better steering capability. SBW system failures, however, can cause hazardous driving situations. This paper introduces fault-tolerant architecture based on diversified steering mechanisms consisting of SBW backed up with steering by braking and acceleration during SBW failures. These backup steering functions are chosen according to driver's intention of deceleration and acceleration. A loss of SBW function during front-obstacle avoidance on a straight highway is investigated by driving simulator experiments. The results show that the driver can maneuver the vehicle by the steering wheel during the SBW failures. Both cost and volume increase by excessive redundancy within SBW is avoided by the diversified design, thus facilitating SBW application on new-generation vehicles