High-speed impedance matching based on muscle characteristic and its application for improving maneuverability of power assist valve

In this paper, we report the development of a power-assisted valve for fire engines. In Japan, the number of fire fighters is decreasing year by year; therefore, it is important to reduce the amount of labor involved in firefighting. Although the development of an automatic system is possible in strictly technical terms, firefighting regulations in Japan require that the valve be operated by hand. In this study, we aim to develop a power-assisted system that can be controlled in accordance with the intent of the operator. First, we confirm a relationship between the impedance parameters and valve opening time. From this relationship, we propose a method for predicting the valve opening time based on the initial value of the operation torque. Evaluating this method, we found that the average operation torque and average tracking error are improved by a factor of two. Second, we reduce prediction error by using a real-time prediction method. While a prediction method based on initial torque can adjust parameters only once, the proposed real-time prediction method can update parameters continuously. As a result, the evaluation score of the method improved from 0.55 to 0.35, and average prediction error was improved from 295ms to 205ms.