Abstract: A method of controlling a vibrational transducer, the method comprising: tracking a temperature metric of the vibrational transducer; and controlling a drive signal for the vibrational transducer, where the drive signal is limited to a value to protect the vibrational transducer from over excursion, and where said value is a function of the tracked temperature metric.

Abstract: A method for estimating actuator parameters for an actuator, in-situ and in real-time, may include driving the actuator with a test signal imperceptible to a user of a device comprising the actuator during real-time operation of the device, measuring a voltage and a current associated with the actuator and caused by the test signal, determining one or more parameters of the actuator based on the voltage and the current, determining an actuator type of the actuator based on the one or more parameters, and controlling a playback signal to the actuator based on the actuator type.

Abstract: In accordance with embodiments of the present disclosure, a method of driving a playback waveform to an electromagnetic actuator by a transducer driving system may include operating the transducer driving system in a first mode wherein the electromagnetic actuator is driven with the playback waveform in a closed loop to form a closed-loop voltage drive system that includes a negative impedance, operating the transducer driving system in a second mode wherein the electromechanical actuator is driven with the playback waveform in an open loop, and operating a mode switch for transitioning the transducer driving system to operate between the first mode and the second mode.

Abstract: A method for determining and mitigating over-excursion of an internal mass of an under-damped electromechanical transducer may include transforming an electrical playback signal to an estimated displacement signal, based on the estimated displacement signal, determining an estimated over-excursion of the internal mass responsive to the electrical playback signal, and limiting, based on the estimated over-excursion, an electrical driving signal derived from the electrical playback signal and for driving the electromechanical transducer in order to mitigate over-excursion of the internal mass.

Abstract: A method for determining and mitigating over-excursion of an internal mass of an electromechanical transducer may include measuring a sensed signal associated with the electromechanical transducer in response to a driving signal driven to the electromechanical transducer, determining a non-linearity value based on the sensed signal, mapping the non-linearity value to a probability of over-excursion of the internal mass, and applying a gain to a signal path configured to generate the driving signal based on the probability.

Abstract: A method may include measuring an electrical parameter of an electromagnetic load having a moving mass during the absence of a driving signal actively driving the electromagnetic load, measuring a mechanical parameter of mechanical motion of a host device comprising the electromagnetic load, correlating a relationship between the mechanical parameter and the electrical parameter, and calibrating the electromagnetic load across a plurality of mechanical motion conditions based on the relationship.

Abstract: A method for minimizing post-playback oscillation during playback of a haptic playback waveform to a haptic transducer may include determining whether a frequency response of the haptic playback waveform has a notch with a notch frequency at approximately a resonant frequency of the haptic transducer and, responsive to the notch frequency differing from the resonant frequency, modifying the haptic playback waveform for playback to the haptic transducer by shifting the notch frequency to approximately the resonant frequency.

Abstract: In accordance with embodiments of the present disclosure, a method of driving a playback waveform to an electromagnetic actuator by a transducer driving system may include operating the transducer driving system in a first mode wherein the electromagnetic actuator is driven with the playback waveform in a closed loop to form a closed-loop voltage drive system that includes a negative impedance, operating the transducer driving system in a second mode wherein the electromechanical actuator is driven with the playback waveform in an open loop, and operating a mode switch for transitioning the transducer driving system to operate between the first mode and the second mode.

Abstract: A method for estimating actuator parameters for an actuator, in-situ and in real-time, may include driving the actuator with a test signal imperceptible to a user of a device comprising the actuator during real-time operation of the device, measuring a voltage and a current associated with the actuator and caused by the test signal, determining one or more parameters of the actuator based on the voltage and the current, determining an actuator type of the actuator based on the one or more parameters, and controlling a playback signal to the actuator based on the actuator type.

Abstract: A system for detecting displacement of a movable member of an electromagnetic transducer having a magnetic coil-driven linear actuator with a static member and a movable mass mechanically coupled to the static member and having a back electromotive force present across terminals of a coil of the electromagnetic transducer is provided. The system may include a resistive-inductive-capacitive sensor comprising the coil, a driver configured to drive the resistive-inductive-capacitive sensor with a driving signal, a measurement circuit communicatively coupled to the resistive-inductive-capacitive sensor and configured to measure one or more of phase information and amplitude information associated with the resistive-inductive-capacitive sensor and based on the one or more of phase information and amplitude information, determine a displacement of movable mass, wherein the displacement of the movable mass causes a change in an impedance of the resistive-inductive-capacitive sensor.

Abstract: A method may include measuring an electrical parameter of an electromagnetic load having a moving mass during the absence of a driving signal actively driving the electromagnetic load, measuring a mechanical parameter of mechanical motion of a host device comprising the electromagnetic load, correlating a relationship between the mechanical parameter and the electrical parameter, and calibrating the electromagnetic load across a plurality of mechanical motion conditions based on the relationship.

Abstract: A method for minimizing undesired movement of a moving mass of an electromagnetic load may include detecting undesired movement of the moving mass based on real-time measurements of one or more parameters associated with the electromagnetic load and, responsive to detecting undesired movement of the moving mass, affecting a signal applied to the moving mass to reduce the undesired movement.

Abstract: According to embodiments described herein, there are provided methods and apparatus for providing a driving signal to a transducer, wherein the driving signal is output by an amplifier. A method comprises receiving an indication of a voltage and a current of the driving signal; based on an electrical model of the transducer and the voltage and the current of the driving signal, estimating an estimated electrical response of the transducer representative of movement of a mass in the transducer; comparing the estimated electrical response to a desired electrical response; and controlling the driving signal based on the comparison.

Abstract: A method for minimizing settling of a moving mass of an electromagnetic load may include determining a polarity and a magnitude of a velocity of the moving mass based on real time measurements of one or more parameters associated with the electromagnetic load and based on the polarity and the magnitude of the velocity, generating a braking signal to be applied to the moving mass that opposes the polarity of the velocity.

Abstract: A method for minimizing settling of a moving mass of an electromagnetic load may include determining a polarity and a magnitude of a velocity of the moving mass based on real time measurements of one or more parameters associated with the electromagnetic load and based on the polarity and the magnitude of the velocity, generating a braking signal to be applied to the moving mass that opposes the polarity of the velocity.

Abstract: A method for minimizing post-playback oscillation during playback of a haptic playback waveform to a haptic transducer may include determining whether a frequency response of the haptic playback waveform has a notch with a notch frequency at approximately a resonant frequency of the haptic transducer and, responsive to the notch frequency differing from the resonant frequency, modifying the haptic playback waveform for playback to the haptic transducer by shifting the notch frequency to approximately the resonant frequency.

Abstract: According to embodiments described herein, there is provided methods and apparatus for providing a driving signal to a transducer, wherein the driving signal is output by an amplifier. A method comprises receiving an indication of a voltage and a current of the driving signal; based on an electrical model of the transducer and the voltage and the current of the driving signal, estimating an estimated electrical response of the transducer representative of movement of a mass in the transducer; comparing the estimated electrical response to a desired electrical response; and controlling the driving signal based on the comparison.