Abstract: Embodiments described herein provide an audio device and a method of operating the audio device. The audio device comprises at least one surface, a first surface transducer positioned to excite first modes of oscillation in a first surface of the at least one surface, and a second surface transducer positioned to excite second modes of oscillation in a second surface of the at least one surface, wherein the first modes of oscillation are of a higher frequency than the second modes of oscillation.

Abstract: A system includes a sequencer that divides a reference waveform into reference sequences, a sequence adjuster, and a model that models non-linearities of a haptic rendering signal chain that includes a haptic transducer load and a driver to the load. For each reference sequence: the sequence adjuster transforms the reference sequence into a test sequence using one or more parameters (e.g., changes reference sequence amplitude and/or period), the model generates an output in response to the test sequence, an error signal is generated that measures a difference between the output and the reference sequence, and if the error signal is above a threshold the parameters are adjusted based on the error signal. These operations are repeated until the error signal is below the threshold in which case the test sequence becomes a selected sequence, which is then sent to the haptic rendering signal chain.

Abstract: Embodiments described herein provide an audio device and a method of operating the audio device. The audio device comprises at least one surface, a first surface transducer positioned to excite first modes of oscillation in a first surface of the at least one surface, and a second surface transducer positioned to excite second modes of oscillation in a second surface of the at least one surface, wherein the first modes of oscillation are of a higher frequency than the second modes of oscillation.

Abstract: A method for controlling one or more parameters of an amplifier system may include receiving an indication of a physical quantity associated with the amplifier system, determining one or more parameters of the amplifier system in response to the indication, and causing the amplifier system to operate in accordance with the one or more parameters.

Abstract: A system may include a vibrating surface, a first mechanical transducer mechanically coupled to the vibrating surface, a second mechanical transducer mechanically coupled to the vibrating surface at a location different than that of the first mechanical transducer, a first signal path for driving the first mechanical transducer, wherein the first signal path comprises a first amplifier and a first filter having a first frequency response, a second signal path for driving the second mechanical transducer, wherein the second signal path comprises a second amplifier and a second filter having a second frequency response, and a control subsystem.

Abstract: A bass enhancement may be applied to improve the perception of low-frequency sounds by a user of an electronic device. A distortion function may be applied to the audio signal that results in creation of higher frequency content related to the low-frequency sounds. This higher frequency content may be interpreted by a listener's ear in a similar manner as the low-frequency sounds. The distortion function may be a Sigmoid function. Bass enhancements may also include scaling of the audio signal prior to distortion, adaptation of the distortion, or gap band filtering prior to the distortion.

Abstract: A system may include an electromagnetic load capable of generating a haptic event and a haptic processor configured to receive at least one first parameter indicative of a desired perception of the haptic event to a user of a device comprising the electromagnetic load, receive at least one second parameter indicative of one or more characteristics of the device, and process the at least one first parameter and the at least one second parameter to generate a driving signal to the electromagnetic load in order to produce the desired perception to the user despite variances in the device that cause an actual perception of the haptic event to vary from the desired perception.

Abstract: The application describes techniques for adaptively setting a threshold that will be used to determine the gain applied to a haptics signal.

Abstract: A method for determining a direct current impedance of a transducer may include receiving an input signal indicative of an electrical power consumed by the transducer and calculating, by a thermal model of the transducer, the direct current impedance based on the electrical power.

Abstract: A system includes a sequencer that divides a reference waveform into reference sequences, a sequence adjuster, and a model that models non-linearities of a haptic rendering signal chain that includes a haptic transducer load and a driver to the load. For each reference sequence: the sequence adjuster transforms the reference sequence into a test sequence using one or more parameters (e.g., changes reference sequence amplitude and/or period), the model generates an output in response to the test sequence, an error signal is generated that measures a difference between the output and the reference sequence, and if the error signal is above a threshold the parameters are adjusted based on the error signal. These operations are repeated until the error signal is below the threshold in which case the test sequence becomes a selected sequence, which is then sent to the haptic rendering signal chain.

Abstract: A method for identifying a mechanical impedance of an electromagnetic load may include generating a waveform signal for driving an electromagnetic load, the waveform signal comprising a first tone at a first driving frequency and a second tone at a second driving frequency. The method may also include during driving of the electromagnetic load by the waveform signal or a signal derived therefrom, receiving a current signal representative of a current associated with the electromagnetic load and a back electromotive force signal representative of a back electromotive force associated with the electromagnetic load.

Abstract: A system may include a signal generator configured to generate a raw waveform signal and a modeling subsystem configured to implement a discrete time model of an electromagnetic load that emulates a virtual electromagnetic load and further configured to modify the raw waveform signal to generate a waveform signal for driving the electromagnetic load by modifying the virtual electromagnetic load to have a desired characteristic, applying the discrete time model to the raw waveform signal to generate the waveform signal for driving the electromagnetic load, and applying the waveform signal to the electromagnetic load.

Abstract: A system for performing force sensing with an electromagnetic load may include a signal generator configured to generate a signal for driving an electromagnetic load and a processing subsystem configured to monitor at least one operating parameter of the electromagnetic load and determine a force applied to the electromagnetic load based on a variation of the at least one operating parameter.

Abstract: A method for identifying a mechanical impedance of an electromagnetic load may include generating a waveform signal for driving an electromagnetic load and, during driving of the electromagnetic load by the waveform signal or a signal derived therefrom, receiving a current signal representative of a current associated with the electromagnetic load and a back electromotive force signal representative of a back electromotive force associated with the electromagnetic load. The method may also include implementing an adaptive filter to identify parameters of the mechanical impedance of the electromagnetic load, wherein an input of a coefficient control for adapting coefficients of the adaptive filter is a first signal derived from the back electromotive force signal and a target of the coefficient control for adapting coefficients of the adaptive filter is a second signal derived from the current signal.

Abstract: A system for estimating parameters of an electromagnetic load may include an input for receiving an input excitation signal to the electromagnetic load, a broadband content estimator that identifies at least one portion of the input excitation signal having broadband content, and a parameter estimator that uses the at least one portion of the input excitation signal to estimate and output one or more parameters of the electromagnetic load.

Abstract: A system for thermally protecting an amplifier driving a capacitive load may include a low-pass filter configured to filter, with a variable cutoff frequency, an input signal to generate a filtered input signal, wherein the amplifier is configured to receive the filtered input signal and amplify the filtered input signal to generate a driving signal to the capacitive load and a controller configured to receive a real-time estimate of a temperature associated with the amplifier and vary the variable cutoff frequency as a function of the temperature.

Abstract: A system may include an input configured to receive a first signal representative of a second signal to be driven to an amplifier input of an amplifier, processing circuitry configured to process the first signal in order to generate the second signal from the first signal such that the processing circuitry limits a current driven by the amplifier to an output load of the amplifier, and an output configured to drive the second signal to the amplifier input.

Abstract: A method for identifying a mechanical impedance of an electromagnetic load may include generating a waveform signal for driving an electromagnetic load, the waveform signal comprising a first tone at a first driving frequency and a second tone at a second driving frequency. The method may also include during driving of the electromagnetic load by the waveform signal or a signal derived therefrom, receiving a current signal representative of a current associated with the electromagnetic load and a back electromotive force signal representative of a back electromotive force associated with the electromagnetic load.

Abstract: A system for vaporizing and optionally decomposing a reagent, such as aqueous ammonia or urea, which is useful for NOx reduction, includes a cyclonic decomposition duct, wherein the duct at its inlet end is connected to an air inlet port and a reagent injection lance. The air inlet port is in a tangential orientation to the central axis of the duct. The system further includes a metering valve for controlling the reagent injection rate. A method for vaporizing and optionally decomposing a reagent includes providing a cyclonic decomposition duct which is connected to an air inlet port and an injection lance, introducing hot gas through the air inlet port in a tangential orientation to the central axis of the duct, injecting the reagent axially through the injection lance into the duct; and adjusting the reagent injection rate through a metering valve.

Abstract: A system may include a vibrating surface, a first mechanical transducer mechanically coupled to the vibrating surface, a second mechanical transducer mechanically coupled to the vibrating surface at a location different than that of the first mechanical transducer, a first signal path for driving the first mechanical transducer, wherein the first signal path comprises a first amplifier and a first filter having a first frequency response, a second signal path for driving the second mechanical transducer, wherein the second signal path comprises a second amplifier and a second filter having a second frequency response, and a control subsystem.