Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : March 17, 2021 - March 18, 2021
In recent years, various problems have become apparent in Japan's transportation system, such as high dependence on automobiles, environmental pollution problems caused by automobile exhaust, and restrictions on mobility for the elderly due to the aging of the population. Personal mobility vehicles (PMV) are expected to solve these problems, and their development is underway. PMVs are characterized by the fact that the mass ratio of the vehicle to the mass of the driver is small, and the force exerted on the vehicle by the driver has a large effect on the vehicle's motion. This means that the force exerted on the vehicle by the driver has a large effect on the vehicle's motion. Therefore, there is a risk of the vehicle tipping over under driving conditions where the force exerted by the driver on the vehicle increases, such as during emergency braking or sudden turns. In order to design a safe PMV, it is very important to consider the dynamic characteristics of the driver, rather than focusing only on the vehicle motion. Currently, most of the driver models used in the safety evaluation of PMV are either body center-of-gravity models or rigid-body link models, and their control systems are usually constructed as passive systems such as spring-damper systems defined by constant terms. In reality, humans actively control their bodies by intention. In evaluating the dynamic characteristics of PMV, it is necessary to use a driver model on PMV that reflects human intentions, but such a model does not currently exist.
In this study, with the goal of constructing a driver model that reflects human intentions, we focused on the joint moment as a parameter to understand the human intentions. We developed a system for estimating the joint moment of a driver while riding a standing PMV, and evaluated the dynamic characteristics of the driver while riding the vehicle by conducting vehicle driving experiments on healthy adult males.
As a result, it was found that the driver controlled the speed of his own body center of gravity before braking in order to stabilize his posture during emergency braking. In addition to that, by evaluating the magnitude of the load on the joints, it was confirmed that the load on the joints was reduced in driving with intention compared with that in driving without intention.
