Among others, off-road motorcycles are subject to changes in road surface conditions depending on weather conditions, and the influence of riding operation on their behavior is significant. Therefore, for consistent evaluation of handling stability, it is effective to quantitatively understand the amount of riding operation and vehicle behavior through data measurement.
However, when riding off-road motorcycles, the impact on the vehicle is large, and there are problems with the impact resistance of the measurement equipment.
There is also a high risk of damage to sensors due to entrapment of mud or stones, etc. Therefore, when using high-precision sensors, it is necessary to proceed with careful operational verification. In particular, since off-road motorcycles are designed to be lightweight, measurement equipment for them must be lightweight as well and compact enough to avoid possible large impact on the vehicle's dynamic characteristics.
Due to such strict requirements for data measurement, there have been few reports on vehicle behavior because measurement and analysis have not been sufficiently conducted.
Therefore, in this study, we focused on the measurement and analysis of vehicle attitude caused by riding operation, which is a typical vehicle behavior, with the measurement equipment mounted in such a way that it does not interfere with riding operation while meeting the measurement requirements. Because straight driving is relatively common on the course in general and the influence of riding operation is relatively small during straight driving, we focused on the pitch angle as the vehicle attitude.
The pitch angle is estimated by using (1) suspension deformation using a potentiometer and (2) an inertial sensor. First, we decided to use the inexpensive method (1), which is also used in the study by Yagi et al (1). Next, we conducted (2).
As a result, we were able to estimate the pitch angle, which is the vehicle attitude due to riding operation on motocross and cross-country courses, and confirm the vehicle behavior. From these results, it was found that the vehicle behavior caused by riding operation during off-road motorcycle driving can be quantitatively demonstrated.