Abstract: A sensor subsystem is disclosed. The sensor subsystem includes a sensor coupled to an interface circuit. The sensor may generate a fine sensor signal and a coarse sensor signal based on a rotation of the sensor. The interface circuit may generate first and second absolute angle values based on the fine and coarse sensor signals, respectively. The interface circuit may additionally generate an output angle value using a difference between the first and second absolute angle values.

Abstract: Measurement systems, methods for operating an angular sensor interface, and angular sensor interfaces. The measurement system includes a position sensor, a signal processor, and a propagation delay compensation filter. The position sensor is configured to generate analog signals. The signal processor is configured to generate position signals from the analog signals. The propagation delay compensation filter is configured to generate low-pass filtered position signals from the position signals, and calculate speed signals from the low-pass filtered position signals. The propagation delay compensation filter is further configured to generate low-pass filtered speed signals from the speed signals, and calculate acceleration signals from the low-pass filtered speed signals. The propagation delay compensation filter is further configured to generate low-pass filtered acceleration signals from the acceleration signals.

Abstract: Some embodiments are directed to a computer-implemented method of determining encrypted computation parameters for carrying out an encrypted computation on noisy ciphertexts. A computation graph is divided into multiple subgraphs, defined by a type and by instantiation parameters for the type. Respective sets of encrypted computation parameters are defined for the respective types. An optimization of the encrypted computation parameters is performed to minimize a computational cost of carrying out the encrypted computation according to the encrypted computation parameters. The encrypted computation parameters are constrained to satisfy a noise constraint on ciphertext noise while carrying out the encrypted computation. The noise constraint is based on respective noise constraints for respective subgraphs, defined by a noise constraint function for the type that takes at least the encrypted computation parameters for the type and the instantiation parameters of the subgraph as input.

Abstract: An inductive sensor may track an angle of a movable element. In some cases, it is desirable to operate the inductive sensor using battery power so that turns are tracked properly even when power is lost. The disclosed inductive sensor includes circuitry to conserve power, such as a non-resonant driver that allows for fast measurements without wasting energy and a difference encoder that can estimate the angle within a range without the need for digitization and complicated processing.

Abstract: An inductive position sensor can include a first target coil, included in a target, and including a first outer lobe that has a size based on a first shift ratio of a harmonic period of a receiver coil, and a first inner lobe having a size based on a second shift ratio of the harmonic period where the harmonic period corresponds with a harmonic and the first shift ratio is different from the second shift ratio. The inductive position sensor also include a second target coil including a second outer lobe having a size based on the second shift ratio, and a second inner lobe having a size based on the first shift ratio.

Abstract: A method for determining authenticity of a document is provided that includes receiving, by an electronic device, an image of a document, assigning a label to the image, and obtaining vectors for each image in a subset of images. Each image is of a document and is assigned the same label as the received image. Moreover, the method includes encoding the received image into a vector, calculating a distance between the vector of the received image and each obtained vector, comparing each of the calculated distances against a threshold distance, and calculating a number of the calculated distances that are less than or equal to the threshold distance. In response to determining the calculated number is at least equal to a required number, the document in the received image is determined to be authentic. Otherwise, the received image requires manual review.

Abstract: An inductive sensor may track an angle of a movable element. In some cases, it is desirable to operate the inductive sensor using battery power so that turns are tracked properly even when power is lost. The disclosed inductive sensor includes circuitry to conserve power, such as a non-resonant driver that allows for fast measurements without wasting energy and a difference encoder that can estimate the angle within a range without the need for digitization and complicated processing.

Abstract: A receiver coil of an inductive angular position sensor can have circuit features that become smaller than reasonable for high resolution measurement designs. This is especially true when multiple receiver coils are used, such as in a three-phase configuration, and when each of the multiple receiver coils is in a twisted loop configuration. The disclosed inductive angular position sensor utilizes different spatial frequencies for a rotor coil and the receiver coils. For example, the spatial frequency of the receiver coils may be kept smaller than the rotor coil. In this condition, the fundamental frequency of the angular position sensor is shifted to the least common multiple of the spatial frequencies, making the angular resolution of the inductive angular position sensor high, while the circuit features of the receiver coils are maintained at a reasonable size.

Abstract: A receiver coil of an inductive angular position sensor can have circuit features that become smaller than reasonable for high resolution measurement designs. This is especially true when multiple receiver coils are used, such as in a three-phase configuration, and when each of the multiple receiver coils is in a twisted loop configuration. The disclosed inductive angular position sensor utilizes different spatial frequencies for a rotor coil and the receiver coils. For example, the spatial frequency of the receiver coils may be kept smaller than the rotor coil. In this condition, the fundamental frequency of the angular position sensor is shifted to the least common multiple of the spatial frequencies, making the angular resolution of the inductive angular position sensor high, while the circuit features of the receiver coils are maintained at a reasonable size.

Abstract: Various embodiments provide a filter for propagation delay compensation and interpolation in encoder digital signal processing. The filter can include a first low pass filter configured to reduce noise of a digital input comprising a measured angular position; a first differentiator configured to receive a filtered digital input and to calculate a speed from a difference in time of the measured angular position and a previous angular position; a second low pass filter configured to reduce noise from the speed; a second differentiator configured to receive a filtered speed and to calculate acceleration using a difference in time of the filtered speed and a previous speed; a third low pass filter configured to reduce noise of the acceleration; and a delay compensator configured to receive the filtered digit input, the filtered speed, and a filtered acceleration, and to calculate a propagation delay compensated digital output.

Abstract: An inductive position sensor subsystem is disclosed. The inductive position sensor includes a fine rotor located on a first printed circuit board, and a metallic coarse rotor including a metal support to which the first printed circuit board is coupled. The inductive position sensor also includes a fine sensor receiver and a coarse sensor receiver that generate respective pluralities of sensor signals based on the rotation of the fine rotor and the metallic coarse rotor. The fine sensor receiver and the coarse sensor receiver are located on a second printed circuit board separate from the first printed circuit board.

Abstract: In at least one aspect, an inductive position sensor comprising a target. The inductive position sensor can include a stator including an excitation coil being inductively coupled to the target, and a receiver coil including a first loop connected in series with a second loop, and inductively coupled with the target such that a receiver coil voltage is generated at the receiver coil. The second loop can be offset, on the stator and relative to the first loop, by a portion of a harmonic period corresponding with a harmonic for nullification in the receiver coil voltage. The inductive position sensor can include a control unit configured to receive a plurality of receiver coil voltages including the receiver coil voltage, the control unit configured to generate an angular position signal based on the plurality of receiver coil voltages.

Abstract: A receiver coil of an inductive angular position sensor can have circuit features that become smaller than reasonable for high resolution measurement designs. This is especially true when multiple receiver coils are used, such as in a three-phase configuration, and when each of the multiple receiver coils is in a twisted loop configuration. The disclosed inductive angular position sensor utilizes different spatial frequencies for a rotor coil and the receiver coils. For example, the spatial frequency of the receiver coils may be kept smaller than the rotor coil. In this condition, the fundamental frequency of the angular position sensor is shifted to the least common multiple of the spatial frequencies, making the angular resolution of the inductive angular position sensor high, while the circuit features of the receiver coils are maintained at a reasonable size.

Abstract: An inductive sensor may track an angle of a movable element. In some cases, it is desirable to operate the inductive sensor using battery power so that turns are tracked properly even when power is lost. The disclosed inductive sensor includes circuitry to conserve power, such as a non-resonant driver that allows for fast measurements without wasting energy and a difference encoder that can estimate the angle within a range without the need for digitization and complicated processing.

Abstract: Various embodiments provide a filter for propagation delay compensation and interpolation in encoder digital signal processing. The filter can include a first low pass filter configured to reduce noise of a digital input comprising a measured angular position; a first differentiator configured to receive a filtered digital input and to calculate a speed from a difference in time of the measured angular position and a previous angular position; a second low pass filter configured to reduce noise from the speed; a second differentiator configured to receive a filtered speed and to calculate acceleration using a difference in time of the filtered speed and a previous speed; a third low pass filter configured to reduce noise of the acceleration; and a delay compensator configured to receive the filtered digit input, the filtered speed, and a filtered acceleration, and to calculate a propagation delay compensated digital output.

Abstract: A vernier sensor including a coarse sensor and a fine sensor may require calibration to ensure accurate position measurements. Calibration may include determining coefficients for harmonics that can be added to the coarse sensor output and the fine sensor output to reduce harmonic distortion. The disclosure describes using the offset and variance of a difference signal as the basis for calibration. This approach is possible at least because the frequencies of the coarse sensor and fine sensor can be selected to reduce the complexity of these calculations.

Abstract: A method of host-directed illumination for verifying the validity of biometric data of a user is provided that includes capturing biometric data from a user with an authentication device during authentication and directing illumination of the biometric data from a host authentication system during the capturing operation. Moreover, the method includes comparing illumination characteristics of the captured biometric data against illumination characteristics expected to result from the directing operation, and determining that the user is a live user when the illumination characteristics of the captured biometric data match the illumination characteristics expected to result from the directing operation.

Abstract: A skimmer apparatus comprising: a buoyant horizontal structure, a pocket-shaped net, a guide element longer than the buoyant horizontal structure and associated to the said buoyant horizontal structure, at least two ends of the buoyant horizontal structure are coupled to at least two parallel expanders, the ends of the at least two parallel expanders being attached to the pocket-shaped net (20).

Abstract: Various embodiments provide a filter for propagation delay compensation and interpolation in encoder digital signal processing. The filter can include a first low pass filter configured to reduce noise of a digital input comprising a measured angular position; a first differentiator configured to receive a filtered digital input and to calculate a speed from a difference in time of the measured angular position and a previous angular position; a second low pass filter configured to reduce noise from the speed; a second differentiator configured to receive a filtered speed and to calculate acceleration using a difference in time of the filtered speed and a previous speed; a third low pass filter configured to reduce noise of the acceleration; and a delay compensator configured to receive the filtered digit input, the filtered speed, and a filtered acceleration, and to calculate a propagation delay compensated digital output.

Abstract: A receiver coil of an inductive angular position sensor can have circuit features that become smaller than reasonable for high resolution measurement designs. This is especially true when multiple receiver coils are used, such as in a three-phase configuration, and when each of the multiple receiver coils is in a twisted loop configuration. The disclosed inductive angular position sensor utilizes different spatial frequencies for a rotor coil and the receiver coils. For example, the spatial frequency of the receiver coils may be kept smaller than the rotor coil. In this condition, the fundamental frequency of the angular position sensor is shifted to the least common multiple of the spatial frequencies, making the angular resolution of the inductive angular position sensor high, while the circuit features of the receiver coils are maintained at a reasonable size.