Abstract: A control system for cleaning and monitoring a sensor assembly disposed externally on a vehicle is provided and includes a contaminant detection/identification sub-system that measures a resonant frequency of the sensor assembly to detect contaminants disposed on an exposed surface of the sensor assembly. A cleaning sub-system is provided and includes cleaning modes that expel the contaminants from the exposed surface of the sensor assembly. A temperature monitoring device monitors a temperature of an actuator disposed in the sensor assembly and a fault detection device detects faults in the sensor assembly.

Abstract: Lens cleaning systems, drivers and methods to detect faults or degradation in a lens cleaning system, including a controller to control a lens transducer drive signal frequency to vibrate the lens in a frequency range of interest and measure frequency response values according to driver feedback signals, and to compare the measured frequency response values to baseline frequency response values for a healthy system, and to selectively determine the existence of a fault or degradation in the lens cleaning system according to dissimilarities between the measured frequency response values and the baseline frequency response values.

Abstract: An apparatus for mitigating contamination of an optical device comprises an open-topped, closed-sided, and closed-bottomed housing cup partially defining a protected volume to enclose the optical device. A housing cap encloses a top of the housing cup and partially defines the protected volume. The housing cap includes a top collar having an open central aperture. A top cover laterally spans the central aperture of the top collar. An interface structure circumscribes the top cover to suspend the top cover downwardly into the housing cup from the top collar. The interface structure prevents direct contact between the top cover and the top collar.

Abstract: An example fault detection circuit includes: a positive sequence voltage calculator to calculate a positive sequence voltage value for a three-phase motor; a positive sequence current calculator to calculate a positive sequence current value for the three-phase motor; an interpolator to calculate an expected negative sequence voltage value based on the positive sequence voltage value, the positive sequence current value, and measured characteristics of the three-phase motor; a negative sequence voltage calculator to calculate a measured negative sequence voltage value for the three-phase motor; and a fault detector to detect that a winding fault exists in the three-phase motor when a difference between the expected negative sequence voltage value and the measured negative sequence voltage value satisfies a threshold.

Abstract: In described examples, one or more devices include: apparatus including a lens element and a transducer to vibrate the lens element at an operating frequency when operating in an activated state; and controller circuitry. The controller circuitry is arranged to measure an impedance of the apparatus, to determine an estimated temperature of the apparatus in response to the measured impedance, to compare the estimated temperature against a temperature threshold for delineating an operating temperature range of the apparatus, and to toggle an activation state of the transducer in response to comparing the estimated temperature against the temperature threshold.

Abstract: A lens structure system. The system comprises a lens structure and a multi-segmented transducer coupled to the lens structure. The multi-segmented transducer comprises a plurality of segments. For each segment in the plurality of segments, there also is a first conductor and a second conductor electrically coupled to the segment.

Abstract: An apparatus for mitigating contamination of an optical device comprises an open-topped, closed-sided, and closed-bottomed housing cup partially defining a protected volume to enclose the optical device. A housing cap encloses a top of the housing cup and partially defines the protected volume. The housing cap includes a top collar having an open central aperture. The top collar includes at least one drain channel extending longitudinally downward into a top collar top surface and extending across the top collar top surface laterally outward from the central aperture. A top cover laterally spans the central aperture of the top collar. An interface structure circumscribes the top cover to suspend the top cover downwardly into the housing cup from the top collar. The interface structure prevents direct contact between the top cover and the top collar.

Abstract: Methods and apparatus for using two stage ultrasonic lens cleaning for water removal are disclosed. An 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. A signal generator can generate a first signal including a first frequency to be coupled with the ultrasonic transducer mechanically coupled to the surface, and can generate a second signal including a second frequency to be coupled with the ultrasonic transducer mechanically coupled to the surface. Switching circuitry can activate the ultrasonic transducer at the first frequency to reduce the droplet from a first size to a second size, and to activate the ultrasonic transducer at the second frequency to reduce the droplet from the second size to a third size.

Abstract: An apparatus for mitigating contamination of an optical device comprises an open-topped, closed-sided, and closed-bottomed housing cup partially defining a protected volume to enclose the optical device. A housing cap encloses a top of the housing cup and partially defines the protected volume. The housing cap includes a top collar having an open central aperture. A top cover laterally spans the central aperture of the top collar. An interface structure circumscribes the top cover to suspend the top cover downwardly into the housing cup from the top collar. The interface structure prevents direct contact between the top cover and the top collar.

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: Systems, apparatus and methods are presented for sensing or estimating a tilt angle, in which a current flowing in an eccentric mass motor is sensed, and a detector circuit assesses the amplitude of a synchronous component of the motor current and provides an output signal or value indicating a tilt angle relative to a gravitational axis at least partially according to the amplitude of the synchronous component of the motor current.

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: An example fault detection circuit includes: a positive sequence voltage calculator to calculate a positive sequence voltage value for a three-phase motor; a positive sequence current calculator to calculate a positive sequence current value for the three-phase motor; an interpolator to calculate an expected negative sequence voltage value based on the positive sequence voltage value, the positive sequence current value, and measured characteristics of the three-phase motor; a negative sequence voltage calculator to calculate a measured negative sequence voltage value for the three-phase motor; and a fault detector to detect that a winding fault exists in the three-phase motor when a difference between the expected negative sequence voltage value and the measured negative sequence voltage value satisfies a threshold.

Abstract: Motor winding fault detection circuits and methods to detect motor winding faults are disclosed. An example fault detection circuit includes a positive sequence voltage calculator to calculate a positive sequence voltage value for a three-phase motor; a positive sequence current calculator to calculate a positive sequence current value for the three-phase motor; an interpolator to calculate an expected negative sequence voltage value based on the positive sequence voltage value, the positive sequence current value, and measured characteristics of the three-phase motor; a negative sequence voltage calculator to calculate a measured negative sequence voltage value for the three-phase motor; and a fault detector to detect that a winding fault exists in the three-phase motor when a difference between the expected negative sequence voltage value and the measured negative sequence voltage value satisfies a threshold.

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.

Abstract: Methods and apparatus for electrostatic control of expelled material for lens cleaners are disclosed. In certain described examples, an apparatus can expel fluid by atomization from a central area of the surface using an ultrasonic transducer mechanically coupled to the surface. A first electrode can be arranged relative to the central area of the surface. A second electrode can be located in a peripheral area relative to the central area of the surface, in which a voltage can be applied between the first and second electrodes to attract atomized fluid at the peripheral area.

Abstract: Disclosed examples include ultrasonic lens cleaning systems and driver circuits to clean a lens using four or more transducer segments mechanically coupled to the lens, in which the driver circuit provides phase shifted oscillating signals to the transducer segments to generate a mechanical traveling wave rotating around the center axis of the lens to vibrate the lens for improved ultrasonic cleaning.

Abstract: In described examples, a transducer vibrates a lens element at a first frequency and a different second frequency. Controller circuitry selects one of a cleaning mode and a heating mode in response to an estimated temperature of the lens element. The controller circuitry activates the transducer to vibrate the lens element at the first frequency in response to the controller circuitry selecting the cleaning mode. The controller circuitry activates the transducer to vibrate the lens element at the second frequency in response to the controller circuitry selecting the heating mode.

Abstract: In described examples, a transducer vibrates a lens element in a heating mode and a cleaning mode. Controller circuitry activates the transducer in the heating mode in response to an estimated temperature, and activates the transducer in the cleaning mode after the transducer is activated in the heating mode.