Abstract:
An active vibration noise control apparatus uses an adaptive control process, which predicts rear road wheel noise canceling sounds by correcting a front road wheel reference signal or a rear road wheel reference signal with a corrective filter, based on different characteristics of front road wheel suspensions and rear road wheel suspensions.
Abstract:
An ANC apparatus using so-called adaptive control is provided with a cancellation sound output means which outputs front wheel cancellation sound that cancels front wheel vibration noise due to front wheel vibration at a position to be silenced on the basis of a front wheel reference signal, and outputs rear wheel cancellation sound that cancels rear wheel vibration noise due to predicted rear wheel vibration at the position to be silenced on the basis of a rear wheel reference signal, and a turning state detection means which detects a turning state of a vehicle. When a difference in travel trajectory between a front wheel and a rear wheel is detected on the basis of the turning state, the cancellation sound output means suppresses the output of the rear wheel cancellation sound.
Abstract:
An active sound control apparatus includes a delay circuit for delaying the output of a frequency component of a sound effect by delaying an engine rotation frequency signal representative of an engine rotation frequency [Hz], a delay circuit for delaying the output of an amplitude component of the sound effect by delaying an engine rotation frequency change signal representative of an engine rotation frequency change [Hz/second], and delay circuits for delaying the output of all components of the sound effect by delaying a control signal for controlling the outputs of speakers.
Abstract:
A subtractor subtracts an echo canceling signal from a canceling error signal to estimate the resonant noise to be silenced at a position of a microphone, and outputs a first basic signal representing the estimated resonant noise as an input signal supplied to a controller. In the controller, a delay filter generates a second basic signal by delaying the first basic signal by a time value. The controller generates a control signal based on the first basic signal and the second basic signal.
Abstract:
A vehicular sound effect generating apparatus has a controller for determining whether a transmission on a vehicle is a manual transmission or an automatic transmission based on whether a clutch signal is generated or not, and automatically changing weighting gain characteristics as acoustic correcting characteristics stored in a sound pressure adjuster depending on the determined transmission. The vehicular sound effect generating apparatus generates a sound effect in a vehicle cabin depending on the manual transmission or the automatic transmission.
Abstract:
An active noise/vibration/sound control system for a vehicle has an ANC (active noise control apparatus), an AVC (active vibration control apparatus), and an ASC (active sound control apparatus). To prevent the ANC, the AVC, and the ASC from interfering with each other and hence to prevent vehicle cabin environment of vibrations, noise, and sound from being impaired, activation and inactivation of the ANC, the AVC, and the ASC are controlled or their control characteristics are controlled in relation to each other by a weighting variable calculator as a coordination controller, depending on an engine rotation frequency and a frequency change which are representative of a running state of the vehicle as detected by an engine rotation frequency detector and a frequency change detector that serve as a running state detector.
Abstract:
A control characteristics changing unit reads, from an EEPROM, various control parameters in an ANC electronic controller, which correspond to specification information acquired from ECUs. The control characteristics changing unit then outputs control parameters, depending on changed specification information among the read control parameters, as change signals Sm1 through Sm6 to a basic signal generating unit, reference signal generating units, filter coefficient updating units, corrective signal generating units, switches, and variable-gain amplifiers, respectively.
Abstract:
An active noise control system prevents a continuous muffled sound from being generated as an abnormal sound under a high sound pressure from a speaker when a microphone as a sound detector is covered, and reduces noise immediately when the microphone is uncovered. A first threshold value as an upper limit value and a second threshold value as a lower limit value are provided for the filter coefficient of an adaptive notch filter. When the filter coefficient is greater than the first threshold value, a control sound is faded out according to a forgetting process. When the filter coefficient is smaller than the second threshold value, an adaptive control process is resumed. Even if the microphone is covered, the filter coefficient does not exceed the first threshold value as the upper limit value.
Abstract:
An active noise control device detects composite vibration of a vibration transmitting route to which both vibration of a rotating body caused by generation or transmission of drive force of a vehicle and vibration of a wheel generated by contact between the wheel and a road surface are transmitted. A first reference signal for defining a reference waveform of a canceling sound for canceling vibration noise in a vehicle interior is generated based on the composite vibration. The component of the canceling sound for canceling vibration noise of the rotating body is removed from the first reference signal to generate a second reference signal for defining a reference waveform of the canceling sound for canceling vibration noise of the wheel. The canceling sound is outputted based on the second reference signal.
Abstract:
In an acoustic control system an operation range of an active type noise control device (an ANC device) and an operation range of an active type effect sound control device (an ASC device) are exchanged in accordance with the number of working cylinders of an engine.