抄録
An inverted pendulum vehicle controlled by the movement of the driver’s center of gravity (COG), such as Winglet or Segway is one of the Personal Mobility Vehicles (PMV). PMV is sometimes expected to be used in pedestrian spaces. When a driver brakes suddenly, the driver has to move the COG behind largely and has the potential to lose his balance according to the characteristics of the vehicle control. Therefore, we aim to achieve the vehicle control that is friendly to the driver in emergency. In the previous study, the coupling model of the vehicle and a human is built using Multibody Dynamics and the way to brake an inverted pendulum vehicle automatically is proposed using that model. In this study, we carried out three experiments to decide the timing of the automatic braking system defined as TTC[s] (Time To Collision). First, we carried out two experiments about stopping distance when a driver brakes suddenly or when the automatic brake is operated and compared these results. As the result, it was found that stopping distance is shorter when the automatic brake is operated than when a driver brakes suddenly. In addition, we derived TTC1 (= 0.443 + 0.2323/x) of an inverted pendulum vehicle from the experiment about stopping distance when a driver brakes suddenly. x is relative velocity between the vehicle and the obstacle. Next, we carried out the experiment to identify the reaction of the driver. As the result, it was found that most people tend to brake suddenly when the distance between the vehicle and the obstacle is under 2.5[m]. Finally, we proposed the safety system using TTC and the distance. If the distance between the vehicle and the obstacle is under 2.5[m], when TTC reaches TTC1, the automatic brake is operated.
