Development of the Compact and Light Wheel Forces and Moments Sensor for Motorcycles

Owing to the recent developments in sensors with reduced size and weight, it is now possible to install sensors on a body of a motorcycle to monitor its behavior during running. The analysis of maneuverability and stability has been performed based on the data resulted from measurements by these sensors. The tire forces and moments is an important measurement item in maneuverability and stability studies. However, the tire forces and moments is difficult to measure directly, therefore, it is a common practice to measure the force and the moment acting on the center of the wheel. The measuring device is called a wheel forces and moments sensor, and it is widely used for cars. The development of a wheel forces and moments sensor for motorcycles has difficulty particular to motorcycles. First, motorcycles run with their bodies largely banked, which restricts positioning the sensors. Second, motorcycles are lighter than cars, and a wheel forces and moments sensor may affect the motion of motorcycle. The object of this study is to develop a compact and light wheel forces and moments sensor that minimizes the effect of the sensor on the motion of the motorcycle. First, we will explain the basic mechanism of the sensor. Then, we will demonstrate how the size of the device was reduced and divided into components to meet the constraints on the positioning of the sensor. We will also show the development of a light and high strength wheel forces and moments sensor. Lastly, we will report the results of the measurement of the actual driving test after verifying the measurement accuracy in chassis dynamo testing.