| 摘要 |
<p>PURPOSE:To ensure safety of operator by comparing the average speed with a limit speed, set slightly higher than the upper limit speed at each speed change stage, and actuating an emergency stop mechanism upon detection of an abnormal speed. CONSTITUTION:Neutral signals are added periodically to drive signals and brake signals, transmitted from a CPU 4 to FETs 5 or 6, thus producing a pulse train of one cycle. Voltages are measured at a rotation detecting section 14 for each neutral signal being transmitted every time when the pulse train is repeated. The measurement is carried out for a predetermined time, and an average vehicle speed is determined based on a plurality of thus measured voltages. In other words, an average vehicle speed is calculated based on actual traveling speed of a motor car and then the average vehicle speed is compared with limit speed at each speed change stage. A suitable emergency stop mechanism is actuated if an abnormal speed is detected through the comparison.</p> |
