Abstract
In this paper, based on a very simple physical principle, a simple and convenient speed sensor for a gasoline engine used is developed. The sensor has several favorable features, i.e. small, light, taking little space, sufficient accurate and handling easy in control operation, especially, easy and low-cost in produce. Moreover, the sensor with the same principle and structure is also applicable to a general gasoline engine. The experimental results with an actual in a portable unmanned helicopter (PUH) have sufficiently demonstrated the effectiveness and practicability of the sensor for the application of PUH control.
