Michio Yanagisawa

Development of slit-type pressure differentiator using an isothermal chamber

Recently, measurement of the differentiated value of pressure has become necessary to realize precise control of pneumatic apparatuses. This paper proposes a pressure differentiator that contains a slit-type laminar flow element and an isothermal chamber. The underlying principle and the design method for the sensor are detailed. Then, simulations and experiments are conducted. The results verify the effectiveness of the proposed sensor and its potential in future applications.

Application of minor feedback of flow rate to pressure spring system

In this paper, the quick response laminar flow sensor (QFS), which is newly developed by our research group, is applied to measure and feedback the output flow rate by a spool type servo valve, and the quick flow control loop up to 20 Hz is realized. By this system, affection by the nonlinearity of the spool type servo valve is compensated. Then, the quick flow control loop is adapted to the pressure control in a pressure tank, as constituting a cascade pressure control system. Finally, the cascade pressure control system is applied to the pressure spring system. Better performance, especially lower energy consumption result is presented in this research.