This paper presents a new fault-tolerant control system (FTCS) against actuator failures. The proposed FTCS is based on a hybrid of static and dynamic redundancies. The redundancy-mode is selected appropriately by only a switching logic which is designed from the control performance. Hence, no fault detector is utilized. For all switched modes, a unity high-gain feedback controller with a parallel feedforward compensator is introduced to attain the stabilization and the asymptotic tracking. Because the controller has high robustness with respect to uncertainties, the FTCS can cope with variations in dynamics that is caused by the failure. In this paper, several simulation results for the connected vehicles are shown to confirm the effectiveness of the FTCS.
The paper proposes a rear-end collision warning system for drivers, where the collision risk is adaptively set from driving signals. The system employs the inverse of the time-to-collision with a constant relative acceleration as the risk and the one-class support vector machine as the anomaly detector. The system also utilizes brake sequences for outliers detection. When a brake sequence has a low likelihood with respect to trained hidden Markov models, the driving data during the sequence are removed from the training dataset. This data selection is confirmed to increase the robustness of the system by computer simulations.
We have proposed Flexible Mono-tread mobile Track (FMT) as a mobile mechanism on rough terrain for rescue activity, environmental investigation and planetary explorer, etc. Generally speaking, one has to teleoperate robots under invisible condition. In order to operate the robots skillfully, it is necessary to detect not only condition around the robots and its position but also posture of the robots at any time. Since flexed posture of FMT decides turning radius and direction, it is important to know its posture. FMT has vertebral structure composed of vertebrae as rigid body and intervertebral disks made by flexible devices such as rubber cylinder and spring. Since the intervertebral disks flex in three dimension, traditional sensors such as potentiometers, rotary encoders and range finders can hardly use for measurement of its deformation. The purpose of the paper, therefore, is to measure flexed posture of FMT using a novel flexible displacement sensor. We prove that the flexed posture of FMT with five intervertebral disks can be detected through experiment.