Stiffness and viscous coefficient characteristics for ergonomics chair design

This report presents a study of stiffness, k_s and viscous coefficient, c characteristic on a developed chair apparatus namely Pneumatic Actuated Seating System (PASS). The stiffness and viscous coefficient characteristics represents the spring and damping function respectively. These two characteristics are emulated from spring-damping model to thirty six intelligent pneumatic actuators on PASS. These attributes will facilitate in investigation of ergonomics chair design from the spring and damping effect. We have reported the design and control of the intelligent actuator in the previous paper. Note that the application of actuator on the PASS was also carried out in the recent work. In this report, we have improved the system by introducing a tilt function for reducing gaps between plates. Three subject sitting test were experimentally conducted and values for k_s and c were confirmed.