| 摘要 |
PURPOSE:To efficiently reduce noise in a car room by using unbalanced inertia force and combustion vibratory excitation force of an engine to obtain a phase delay for a crank angle and using a crank angle signal, delayed by the amount of this phase delay, as a synchronous signal at the time of generating a secondary sound. CONSTITUTION:A crank angle in an engine is detected by a sensor 11, while being based on this detection signal, unbalanced inertia force in proportion to the square of an engine speed is calculated in a means 12. While a load of the engine is detected by a sensor 13, while being based on this detection signal, combustion vibratory excitation force is calculated in a means 14. Further being based on the unbalanced inertia force and the combustion vibratory excitation force, a phase delay for the crank angle is calculated in a means 15. While, a crank angle signal, delayed by the amount of the phase delay, is generated by a means 16 as a synchronized signal which is a phase reference value of secondary sound. By using the synchronous signal, a secondary sound signal is generated by a means 17 while it is output to a secondary sound source 19 in a car room by a means 18. |
