キャスタのトー角駆動を用いたブレーキユニットの開発とキャスタワゴンの地震応答低減

抄録

Most medical equipment with casters has a risk of tipping or moving when an earthquake occurs. In the previous study, ER brakes were used to control the seismic response reduction. However, ER brakes needed high voltage and braking property was not linear and base torque was not small, so in this study, variable toe-angle caster system is proposed. It was possible to make it simpler and more compact by using a servomotor and link mechanism, and it was possible to generate sufficient braking force to reduce the seismic response. The performance of reducing the seismic response by the controller using the instantaneous optimum control law was 48.0 %, which is equivalent to that of the ER brake. Furthermore, it was possible to reduce the seismic response by fixing the toe-angle in middle range, and the reduction rate was 51.6 %, which exceeds the control case. It was found that variable toe-angle casters are effective in reducing the seismic response of caster wagons.