Experimental study on human-machine interaction for dynamical balancing control based on a building block type device with parallel two-wheeled vehicles

Body balance is crucial for people to smoothly conduct everyday life. This capability can be divided into two types: static and dynamical. The one-leg balance test with eyes closed is a common test method for the former. But a test for the latter remains undeveloped, and the establishment of the testing method, as well as the training one, is expected. Thus, in this research, we designed and built a building block type device with parallel two-wheeled vehicles, and evaluated human-machine interaction for dynamical balancing control through riding experiments with many subjects. In these experiments that employed the device with a lower level of automatic control, the subjects typically lost their balance immediately. Through trial and error, their ability improved. All eventually and successfully rode continuously after training that varied greatly among individuals. Analysis with an indicator shows that their tendencies can objectively be characterized. From experiments in which the angle between the directions of the rider´s feet and the device wheels was altered to 0, 45, or 90 degrees, we further clarified that similarity exists in their training processes, but the difficulty of riding the device decreased in the order of 0, 45, and 90 degrees. Based on our obtained results, we discuss whether the machine developed in this research has potential as a measurement and training device for human dynamical balancing capability, which will be an important theme in the neural engineering field.