Abstract: A motor control system for a permanent magnet synchronous motor (PMSM) uses two linear Hall devices to produce a first signal indicative of a strength of a first magnetic field component produced by a set of rotor magnets and to simultaneously produce a second signal indicative of a strength of second magnetic field component produced by the rotor magnets that is approximately orthogonal to the first magnetic field component. An angular position and angular velocity of the rotor is calculated based on the first signal and the second signal. A plurality of phase signals is produced based on the calculated angular position and angular velocity. Current in a plurality of field windings of the motor is controlled using the plurality of phase signals.

Abstract: Mechanical vibration may be sensed by a remotely located ultrasonic sensor. An ultrasonic wave may be transmitted from a transmitter to a vibrating surface, in which the transmitter is separated from the vibrating surface by a distance. A reflected portion of the ultrasonic wave that is reflected from the vibrating surface may be received by a receiver that is also separated from the vibrating surface by a distance. A measure of phase shift amplitude in the reflected portion of the ultrasonic wave may be determined and converted into an amplitude of a vibration of the vibrating surface.

Abstract: Disclosed examples include heart rate monitor systems and methods to estimate a patient heart rate or rate of another pulsed signal, in which rate hypotheses or states, are identified for a current time window according to digital sample values of the pulsed signal for a current sample time window, and a rate change value is computed for potential rate transitions between states of the current and previous time windows. Transition pair branch metric values are computed as a function of the rate change value and a frequency domain amplitude of the corresponding rate hypothesis for the current time window, and the pulsed signal rate estimate is determined according to a maximum path metric computed according to the branch metric value and a corresponding path metric value for the previous time window.

Abstract: A method of controlling an electric motor (motor) includes providing a processor having an associated memory storing a stator resistance (Rs) estimation (RSE) algorithm that is programmed to implement the RSE algorithm to execute steps including injecting a current waveform at an arbitrary frame of reference into the stator using a field-oriented-control (FOC) motor controller including an Id controller and an Iq controller, and measuring current and voltage values from the motor responsive to the injecting. The measured current and voltage values are then transformed into transformed current and voltage values in a d/q coordinate system. The transformed current and voltage values are low pass filtered to generate filtered d/q current and voltage values, and a value for Rs is estimated from the filtered d/q current and voltage values. The arbitrary frame of reference can be a time-varying frame of reference.

Abstract: Methods and apparatus for ultrasonic lens cleaner using configurable filter banks are disclosed. In certain described examples, the methods and apparatus can expel fluid from a droplet on an optical surface using an ultrasonic transducer mechanically coupled to the optical surface and having first and second resonant frequency bands.

Abstract: A method of regenerative braking includes providing an electric motor including at least one stator and a rotor, a speed of the rotor, a motor controller that regulates a current level in the stator winding, a power inverter which controls an energy flow to the stator terminal, and an energy storage system (ESS) which exchanges energy with the motor. A battery management circuit is between the power inverter and the ESS, and a processor has an associated memory storing a regenerative braking (RB) algorithm. The RB algorithm during braking causes the motor controller to execute determining an RB torque value from the rotor speed that maximizes regenerative braking current, and the power inverter is used to redirect the RB current to maximize a power transfer from the motor to the ESS.

Abstract: Low speed and high speed estimates of rotor angle and speed relative to the stator are received from a low speed estimator and a high speed estimator, respectively. LS_?_EST and a subset of torque-controlling I_Q trajectory curve (“IQTC”) parameter values appropriate to low speed rotor operation are selected for rotor speeds below a low speed threshold value ?_LOW_THRS. HS_?_EST and a subset of IQTC curve parameter values appropriate to high speed rotor operation are selected for rotor speeds above a high speed threshold value ?_HIGH_THRS. LS_?_EST and the low speed subset of IQTC parameter values remain selected for rotor speeds less than ?_HIGH_THRS after accelerating to a rotor speed greater than ?_LOW_THRS. HS_?_EST and the subset of high speed IQTC parameter values remain selected for rotor speeds greater than ?_LOW_THRS after decelerating to a rotor speed less than ?_HIGH_THRS.

Abstract: In described examples, a method for detecting voice activity includes: receiving a first input signal containing noise; sampling the first input signal to form noise samples; determining a first value corresponding to the noise samples; subsequently receiving a second input signal; sampling the second input signal to form second signal samples; determining a second value corresponding to the second signal samples; forming a ratio of the second value to the first value; comparing the ratio to a predetermined threshold value; and responsive to the comparing, indicating whether voice activity is detected in the second input signal.

Abstract: A method of determining angular position (?) of a rotor of an N-phase permanent magnet motor (PMM). A processor having an associated stored angular position determination (APD) algorithm is programmed to implement the algorithm to cause an associated motor controller to execute steps including forcing one vector at a time a phase vector set of current or voltage vectors to stator terminals of windings for the N-phases a positive and negative magnitude vector, wherein the vector magnitude is sufficiently small to not move the rotor, and a time duration for the forcing current or voltage vectors is essentially constant. The resulting stator current or voltage levels are measured for each current or voltage vector. An N-dimension current vector or voltage vector is generated from superposition of the resulting stator current levels or resulting stator voltage levels. The N-dimension current vector or voltage vector is used to determine angular position.

Abstract: A method of ultrasound flow metering includes applying a first and second pulse train to an ultrasound transducer pair (T1, T2) positioned for coupling ultrasonic waves therebetween. Responsive to the first pulse train applied to T1, T1 transmits an ultrasonic wave received as received ultrasonic wave (R12) by T2 after propagating through fluid in a pipe. Responsive to the second pulse train applied to T2, T2 transmits an ultrasonic wave received as received ultrasonic wave by (R21) T1 after propagating through the fluid. During the pulse trains, R12 and R21 build up in amplitude to provide excitation portions. The pulse trains are terminated, so that R12 and R21 decay as a damped free oscillation. Windowing is applied to R12 and R21 to generate windowed portions. A signal delay between t12 and t21 (?TOF) is calculated using only windowed portions, and a fluid flow is calculated from the ?TOF.

Abstract: In described examples of methods and control systems to control a position and/or velocity of a machine, control circuitry is coupled to receive and dither a control signal, and to compute a control output value according to the dithered control signal and a control function. An inverter is coupled to the control circuitry, to control the position and/or velocity according to the control output value.

Abstract: Disclosed examples include heart rate monitor systems and methods to estimate a patient heart rate or rate of another pulsed signal, in which rate hypotheses or states, are identified for a current time window according to digital sample values of the pulsed signal for a current sample time window, and a rate change value is computed for potential rate transitions between states of the current and previous time windows. Transition pair branch metric values are computed as a function of the rate change value and a frequency domain amplitude of the corresponding rate hypothesis for the current time window, and the pulsed signal rate estimate is determined according to a maximum path metric computed according to the branch metric value and a corresponding path metric value for the previous time window.

Abstract: A method for heart rate measurement in a photoplethysmograph (PPG) heart rate monitor device is provided that includes performing motion compensation on a PPG signal wherein a motion compensated PPG signal PPGaccX is generated with reference to an X-axis acceleration signal, a motion compensated PPG signal PPGaccY is generated with reference to a Y-axis acceleration signal, and a motion compensated PPG signal PPGaccZ is generated with reference to a Z-axis acceleration signal, combining PPGaccX, PPGaccY, and PPGaccZ to generate a final motion compensated PPG signal, wherein a first weight is applied PPGaccX, a second weight is applied to PPGaccY, and a third weight is applied to PPGaccZ, performing a single Fourier Transform (FT) on the final motion compensated PPG signal to generate a frequency domain PPG signal; and estimating a heart rate based on the frequency domain PPG signal.

Abstract: A method of regenerative braking includes providing an electric motor including at least one stator and a rotor, a speed of the rotor, a motor controller that regulates a current level in the stator winding, a power inverter which controls an energy flow to the stator terminal, and an energy storage system (ESS) which exchanges energy with the motor. A battery management circuit is between the power inverter and the ESS, and a processor has an associated memory storing a regenerative braking (RB) algorithm. The RB algorithm during braking causes the motor controller to execute determining an RB torque value from the rotor speed that maximizes regenerative braking current, and the power inverter is used to redirect the RB current to maximize a power transfer from the motor to the ESS.

Abstract: An oscillatory system comprises: a target member; a transducer coupled to the target member; and circuitry for applying a voltage to the transducer for imparting a vibrational force to the target member.

Abstract: A method of determining angular position (0) of a rotor of an N-phase permanent magnet motor (PMM). A processor having an associated stored angular position determination (APD) algorithm is programmed to implement the algorithm to cause an associated motor controller to execute steps including forcing one vector at a time a phase vector set of current or voltage vectors to stator terminals of windings for the N-phases a positive and negative magnitude vector, wherein the vector magnitude is sufficiently small to not move the rotor, and a time duration for the forcing current or voltage vectors is essentially constant. The resulting stator current or voltage levels are measured for each current or voltage vector. An N-dimension current vector or voltage vector is generated from superposition of the resulting stator current levels or resulting stator voltage levels. The N-dimension current vector or voltage vector is used to determine angular position.

Abstract: An example method includes: receiving a test phrase; comparing feature vectors of the test phrase to contents of a first database to generate a first score; comparing the feature vectors of the test phrase to contents of a second database to generate a second score; comparing feature vectors of the contents of the second database to the contents of the first database to generate a third score; comparing the feature vectors of the contents of the second database to a model of the test phrase to generate a fourth score; determining a first difference score based on a difference between the first and second scores; determining a second difference score based on a difference between the third and fourth scores; and generating a difference confidence score based on a lesser of the first and second difference scores.

Abstract: A controller for driving a motor includes a multiphase driver, an analog-to-digital converter (ADC), impedance estimation circuitry, and fault detection circuitry. The multiphase driver is configured to generate drive signals for energizing each motor phase winding. The ADC is configured to digitize voltage and current from each motor phase winding. The impedance estimation circuitry is configured to determine a phasor value for the digitized voltages and for the digitized currents at a predetermined harmonic frequency, and to determine a sequence impedance value based on the phasor values. The fault detection circuitry is configured to identify a fault in the windings of the motor based on the sequence impedance value.

Abstract: An apparatus includes a mass detection circuit coupled to a surface covered with a plurality of electrodes. The mass detection circuit is configured to detect a mass of a first droplet present on the surface. The apparatus further includes a transducer circuit coupled to a transducer, which is coupled to the surface and form a lens unit. The transducer circuit configured to excite a first vibration of the surface at a resonant frequency to form a high displacement region on the surface. The apparatus also includes a voltage excitation circuit coupled to the plurality of electrodes. In response to the detection of the mass of the first droplet, the voltage excitation circuit is configured to apply a sequence of differential voltages on one or more consecutive electrodes which moves the first droplet to the high displacement region.

Abstract: Methods and apparatus for surface wetting control are disclosed. In certain described examples, an apparatus can expel fluid from a droplet on a surface using a transducer mechanically coupled to the surface. A first area of the surface can have a first wettability for the fluid, and a second area of the surface can have a second wettability for the fluid. The first wettability of the first area of the surface can be greater than the second wettability of the second area of the surface. The first area and the second area can be arranged in a patterned arrangement.