Development of System for Study on Human Recognition Influenced by Changing Button-push Sensation

Abstract

Recently, physical buttons that can be operated with a small amount of force are used to operate information devices. Some of them can involve user’s recognition of completing their operation easily. An example of such attempt is the button with nonlinearity in the relationship between stroke and reaction force. There, however, is not enough quantitative evaluation between the sensation of pushing and the perception of operation through buttons yet. The purpose of this study is to quantitatively evaluate the relationship between the sensation of pushing a button and the easiness of operation recognition. In this article, an experimental apparatus fabricated for the quantitative evaluation is introduced. It consists of a voice coil motor as an actuator, a leaf spring that limits the movement direction to the vertical direction, a displacement sensor, a force sensor and a key top. In this experimental apparatus, vertical displacement and force can be controlled. Therefore, kinesthetic sensation during pushing a physical button can be simulated. For the simulation, the force and displacement should be controlled according to the pushing action. To build the controller, parameters such as drive part mass of the experimental apparatus, the leaf spring constant, and the thrust constant of the voice coil motor were identified.