Abstract: Piezoelectric sensor controllers may facilitate detection and identification of various potential fault states with parameter measurements. In an illustrative embodiment of a piezoelectric-based sensor having response-parameter-based fault diagnosis, the sensor includes a piezoelectric transducer and a controller. The controller drives the piezoelectric transducer to generate bursts of acoustic energy and, based on a response of the piezoelectric transducer to said driving, identifies a corresponding transducer state from a set of potential states including multiple transducer fault states.

Abstract: A sensor device coupled to a communication interface bus, the sensor device enters a low power mode in which some operations of the sensor device are suspended when the sensor device receives insufficient power over the bus, thereby significantly reducing the likelihood that digital components of the sensor device will need to be reset due to an under-voltage condition.

Abstract: A sensor device coupled to a communication interface bus, the sensor device includes: a current source having a first terminal operable to receive a supply current, a second terminal operable to provide a supply current, and a control terminal, wherein an operating voltage is supplied by a current through the current source; a voltage clamp having a first terminal coupled to the second terminal of the current source, a second terminal coupled to a power supply terminal, and an output terminal operable to provide a current sense signal; and a control circuit having an input terminal coupled to the output terminal of the voltage clamp and an output terminal coupled to the control terminal of the current source operable to provide an adjustment signal responsive to the current sense signal, wherein the current source is configured to adjust the current through the current source responsive to the adjustment signal.

Abstract: Piezoelectric sensor controllers may facilitate detection and identification of various potential fault states with novel parameter measurements. In an illustrative embodiment of a piezoelectric-based sensor having a shorted-reverberation based resonant frequency measurement, the sensor includes a piezoelectric transducer that provides residual reverberation after being driven. The sensor further includes a controller that provides a low impedance path for the piezoelectric transducer during the residual reverberation and that measures current through the low impedance path to determine a resonant frequency of the piezoelectric transducer.

Abstract: One implementation of a sensing method includes: correlating a receive signal with a first channel waveform template to obtain a first channel correlation signal in which first channel echoes would be represented as peaks; correlating the receive signal with a second channel waveform template to obtain a second channel correlation signal in which second channel echoes would be represented as peaks; and varying the first channel waveform template and the second channel waveform template based on time elapsed from a measurement start time. A sensor array implementation includes: multiple acoustic transducers that operate concurrently to send acoustic bursts in different frequency channels, each of the multiple acoustic transducers configured to use the foregoing method.

Abstract: Various sensors, sensor controllers, and sensor control methods are provided with model-based sideband balancing. In one illustrative embodiment, a controller for a piezoelectric transducer includes a transmitter, a receiver, and a processing circuit coupled to the transmitter and receiver. The processing circuit performs calibration and echo detection, the calibration including: sensing the piezoelectric transducer's phase response as a function of frequency; deriving equivalent circuit parameters for the piezoelectric transducer from the phase response; and determining a sideband imbalance based on one or more of the equivalent circuit parameters. Once the sideband imbalance is identified, the processing circuit may perform echo-detection processing that accounts for the sideband imbalance.

Abstract: Sensors, sensor controllers, and sensor control methods may employ an echo-magnification technique to improve threshold-based echo detection. In one illustrative embodiment, a sensor controller includes: a transmitter, a receiver, and a processing circuit coupled to the transmitter and to the receiver. The transmitter drives a piezoelectric element to generate acoustic bursts. The receiver senses a response of the piezoelectric element to echoes of each acoustic burst. The processing circuit is operable to apply echo-detection processing to the response by: identifying an interval of the response representing at least a portion of a potential echo; deriving a modified response from the response by selectively magnifying the response during said interval; and using the modified response to detect an echo.

Abstract: In one form, a method for acoustic distance measurement includes generating an acoustic signal with an acoustic transducer at a first time. A pulse is detected with the acoustic transducer in response to the acoustic signal encountering an obstacle within a predetermined distance. Detecting the pulse includes detecting a second time relative to the first time when a magnitude of the pulse rises above a predetermined threshold, and detecting a peak magnitude of the pulse. A correction ratio is determined as a ratio of the predetermined threshold to the peak magnitude of the pulse. A correction time is determined in response to the correction ratio. A corrected time-of-flight is determined by adjusting the second time by the compensation time.

Abstract: Embodiments include devices, system and processes for facilitating ultra-short range detection of obstacles using a PAS sensor. A process may include obtaining a correlation of at least two characteristics of a transducer; determining a given transmission frequency and selecting a reverberation time desired for the transducer; obtaining a damping ratio corresponding to the selected reverberation time; generating a ranging signal command; generating a damping signal command; and outputting each of the ranging signal command and the damping signal command. The ranging signal command may instruct a PAS sensor to drive the transducer to output a ranging signal at the given transmission frequency, at a transmission amplitude, and at a transmission phase and the damping signal command results in a dampening, at the damping ratio, of transducer reverberations arising from the ranging signal. The damping ratio may be between thirty percent (30%) and eighty percent (80%) of the transmission amplitude.

Abstract: In one form, an acoustic distance measuring circuit includes a transmitter amplifier, an acoustic transducer, and a sensing circuit. The sensing circuit includes an input adapted to be coupled to the acoustic transducer, a first correlation output for providing a chirp tail correlation signal, and a second output for providing a full chirp correlation signal. The sensing circuit provides the chirp tail correlation signal in response to correlating a chirp tail signal pattern with a received signal, and provides a full chirp correlation signal in response to correlating a full chirp signal pattern with the received signal. Further, the acoustic distance measuring circuit includes a controller adapted to be coupled to the sensing circuit that has a first input for receiving the chirp tail correlation signal and the full chirp correlation signal for determining a short range time of flight signal and a long range time of flight signal.

Abstract: The various embodiments of the present disclosure are directed to devices, system and processes for detecting saturation of a received signal in a PAS system. A process may include detecting, in a received signal and during a measurement interval, one or more correlated signal levels. Based on one or more results of the detecting, the process may include identifying in a correlated output signal portions of the received signal which exceed a given magnitude threshold during the measurement interval and providing the correlated output signal to an electronic control unit (ECU). A magnitude detector outputs the correlated output signal. A saturation detector determines whether the received signal is saturated during a portion of a measurement interval. When the received signal is saturated, a saturation signal is generated and provided on a delayed basis to the ECU such that it is provided substantially contemporaneously with the correlated output signal.

Abstract: An obstacle monitoring system includes a transducer that receives an ultrasonic echo from an obstacle and generates a signal based on the echo. The system further includes a controller coupled to the transducer that is calibrated based on a frequency response of the transducer and a coupling circuit. The system further includes circuitry generating a damping current, controlled by the controller, that reduces or eliminates reverberation of the transducer.

Abstract: Various sensors, sensor controllers, and sensor control methods are provided with model-based sideband balancing. In one illustrative embodiment, a controller for a piezoelectric transducer includes a transmitter, a receiver, and a processing circuit coupled to the transmitter and receiver. The processing circuit performs calibration and echo detection, the calibration including: sensing the piezoelectric transducer's phase response as a function of frequency; deriving equivalent circuit parameters for the piezoelectric transducer from the phase response; and determining a sideband imbalance based on one or more of the equivalent circuit parameters. Once the sideband imbalance is identified, the processing circuit may perform echo-detection processing that accounts for the sideband imbalance.

Abstract: Sensors, sensor controllers, and sensor control methods may employ an echo- magnification technique to improve threshold-based echo detection. In one illustrative embodiment, a sensor controller includes: a transmitter, a receiver, and a processing circuit coupled to the transmitter and to the receiver. The transmitter drives a piezoelectric element to generate acoustic bursts. The receiver senses a response of the piezoelectric element to echoes of each acoustic burst. The processing circuit is operable to apply echo-detection processing to the response by: identifying an interval of the response representing at least a portion of a potential echo; deriving a modified response from the response by selectively magnifying the response during said interval; and using the modified response to detect an echo.

Abstract: A semi-differential signaling technique as well as bus devices and communication systems that exploit this technique to enhance the performance of the DSI3 bus. In one embodiment, there is provided a DSI3 master device that can be coupled to a DSI3 slave device via a bus having at least a power supply conductor, a power return conductor, and a signal conductor. The master device includes: a power supply node and a power return node that respectively connect to the power supply conductor and the power return conductor to supply power to the slave device; a signal node that connects to the signal conductor; and a driver that drives the signal node relative to a reference voltage midway between voltages of the power supply node and the power return node.

Abstract: Sensors may employ a constant false alarm rate (CFAR) screening process in combination with edge-based echo detection. In one illustrative embodiment, a sensor controller includes: a transmitter, a receiver, and a processing circuit coupled to the transmitter and to the receiver. The transmitter drives a piezoelectric element to generate acoustic bursts. The receiver senses a response of the piezoelectric element to echoes of each acoustic burst. The processing circuit is operable to apply echo-detection processing to the response by: determining a derivative signal from the response; and detecting an echo based at least in part on a peak in the derivative signal indicating a rising and/or falling edge in the response. Signaling to the electronic control unit may specify a time of flight associated with each edge.

Abstract: Disclosed DSI3 slave devices may enhance the data rate of the DSI3 bus using modified nibble encoding, pulse shaping, spectral shaping, and/or message preambles to provide chip time and level tracking. In one embodiment, there is provided a communications method that includes: converting a binary data stream into a ternary unipolar non-return-to-zero level channel signal; and driving the channel signal as an electrical current on a signal conductor. The converting uses an encoder that maps binary nibbles to a set of ternary triplets, each triplet in the set having an average level between 2/3 and 4/3 inclusive, and each triplet including at least one internal transition between levels.

Abstract: Piezoelectric sensor controllers may facilitate detection and identification of various potential fault states including noise-induced sensor blindness. In one illustrative embodiment, a sensor controller includes: a transmitter to drive a piezoelectric element during actuation intervals to generate acoustic bursts; a receiver to sense a response of the piezoelectric element to echoes of each acoustic burst, the receiver including a front-end amplifier; a processing circuit coupled to the transmitter and to the receiver, the processing circuit operable to apply echo-detection processing to said response; and a blindness detector to detect saturation of the front-end amplifier during or prior to the measurement intervals.

Abstract: In one form, an acoustic distance measuring circuit includes a frequency generator, a transmitter amplifier, an acoustic transducer, and a sensing circuit. The sensing circuit includes an input adapted to be coupled to the acoustic transducer, for receiving an input signal. The sensing circuit provides an in-phase portion and a quadrature portion of the input signal to a filter. The sensing circuit filters the in-phase portion and the quadrature portion and calculates a phase of the input signal in response to the filtered in-phase and quadrature portions. The sensing circuit determines a frequency slope of the input signal in response to calculating the phase and provides the frequency slope of the input signal to an output.

Abstract: Composite burst signaling to provide robust multi-channel sensor array performance in systems for parking assistance, blind spot monitoring, and driver assistance. An illustrative method embodiment includes driving an acoustic transducer to send composite acoustic bursts. Each composite acoustic burst includes multiple individual bursts associated with respective frequency bands, the frequency band arrangement providing a source-specific burst signature. The method further includes receiving self-generated echo signals responsive to the composite acoustic bursts from the transducer and potentially including extra echoes responsive to acoustic bursts from other sources; categorizing received echo signals by source based on the burst signature; and using the self-generated echoes exclusive of the extra echoes to determine a distance or time of flight from the transducer.