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Methods for motion control with a coupled suspension systems of automobile have been proposed and their effectiveness has been shown by the previous studies. However, it is not easy to couple hydraulic dampers because it requires designing and manufacturing complex pipelines. Recently, the electromagnetic damper, which is composed of an electric motor, a ball screw, and a nut, was proposed. The electromagnetic damper has high responsiveness, controllability, and energy saving performance, and it has been reported they improved ride comfort and drivability. The electromagnetic damper has various function depending on the electric circuit connected to its electric motor and can be connected to each other more easily than that by hydraulic dampers.

This study proposes a method for presenting maneuver request information of accelerator pedal to a driver via the accelerator pedal itself. By applying periodic force like vibration on an accelerator pedal, information is transferred to the driver without displacing the accelerator pedal. In this study, the authors focus on a saw-tooth wave as the periodic force. When the saw-tooth-waved force is applied on the accelerator pedal, a human driver feels as if the accelerator pedal is knocked by someone periodically. In addition, information about the quantity of requested maneuver can be transferred by the amplitude of the saw-tooth wave. Based on these facts, the saw-tooth wave is modified and optimized empirically with ten human drivers so that the information of direction is transferred most reliably. In addition, the relationship between the amplitude of the saw-tooth wave and requested quantity of the pedal maneuver that the drivers feel is formulated.

This study focuses on the scene that a vehicle overtakes a pedestrian in a narrow road in an urban area and proposes the safety index that shows the appropriate driving behavior in the target scene. Moreover, this study evaluates the validity of the index by experiments. In the target scenes, drivers need to drive carefully, preparing for the latent risk that the pedestrians may start crossing the roads suddenly. In other word, the vehicles must reduce the speed in order to be ready to avoid accidental contacts with pedestrians in case the pedestrians start crossing the road suddenly. However, according to the pedestrian model proposed by the authors in the previous study, the crossing angles of pedestrians are unpredictable. Therefore, the drivers must drive with such speed that the vehicle can avoid an accidental contact by braking even if the pedestrian start crossing the road at any angle.