An encoder includes a code disc and a processor communicatively coupled with the code disc. The code disc is configured to rotate along with a rotating object and includes a plurality of fan teeth extending radially. One of the plurality of fan teeth is different from other ones of the plurality of fan teeth, and the other ones of the fan teeth are same to each other. A first portion of a detection signal that is generated in one rotation of the code disc, corresponding to the one of the plurality of fan teeth, is different from a second portion of the detection signal, corresponding to each of the other ones of the fan teeth. The processor is configured to detect the rotation of the code disc to obtain the detection signal and a rotation parameter of the rotating object based on the detection signal.

Methods and systems for testing a sensor of a propeller blade angle position feedback system are described. A sensor signal is received from a sensor at a known position relative to a feedback device, the feedback comprising a ring and at least one pair of position markers spaced from one another around a circumference thereof, the sensor configured for successively detecting passage of the position markers as the feedback device rotates at a known rotational speed and an axial distance between the sensor and the feedback device varies. From the sensor signal a measured position of the sensor relative to the feedback device and a measured rotational speed of the feedback device are determined. The measured position and the measured rotational speed are compared to the known position and the known rotational speed to determine a sensor accuracy.

Systems and techniques to facilitate generating and/or encoding rotational data associated with a mechanical element are presented. A sensor system can measure rotational speed data and phase data associated with a mechanical element that rotates. The sensor system can also encode the rotational speed data and phase data into a digital data packet. Furthermore, the sensor system can transmit the digital data packet associated with the rotational speed data and phase data to one or more sensor devices in communication with the sensor system.

Systems and techniques to facilitate generating and/or encoding rotational data associated with a mechanical element are presented. A sensor system can measure rotational speed data and phase data associated with a mechanical element that rotates. The sensor system can also encode the rotational speed data and phase data into a digital data packet. Furthermore, the sensor system can transmit the digital data packet associated with the rotational speed data and phase data to one or more sensor devices in communication with the sensor system.

A measurement of the rotation speed of an object is made using a time-of-flight sensor configured to detect a passing of one or more of elements of the object through a given position. The time-of-flight sensor is further mounted on a one-person vehicle configured to protect the one-person vehicle against collisions through the making a time-of-flight measurement of a relative speed between the one-person vehicle and an obstacle.

The present disclosure is directed to systems and methods for estimating machine rotation state. The rotation state can include the rotation speed and/or angle as the machine rotates. In some implementations, an estimating machine rotation state system can receive image data, timestamped consecutively, from camera devices of a machine. The estimating machine rotation state system can generate optical flow vectors for the pixels of the image data and determine the hue and intensity of the pixels based on the optical flow vectors. Using the hues, intensities, and timestamps of the image data, the estimating machine rotation state system can generate an intensity plot over time. The estimating rotation states system can then determine a rotation speed of the machine based on the intensity plot. The estimating rotation states system can also determine a rotation angle of the machine by integrating the intensity plot over time.

An encoder includes a measurement target and circuitry. The measurement target includes an absolute pattern and is rotatable. The circuitry is configured to generate, via a processing scheme, a signal representing an absolute position of the measurement target based on the absolute pattern. The circuitry is configured to detect, based on the absolute pattern, whether the measurement target rotates or not. The circuitry is configured to change the processing scheme based on whether the measurement target rotates or not.

Apparatus and associated methods relate to optically determining rotation frequency of a rotatable member using a Fabry-Perot cavity formed between a mirror and a movable reflective mirror. A cavity dimension between the mirror and a movable reflective mirror changes in response to movement of the movable reflective mirror. The movable reflective mirror is bonded to a magneto-strictive material having a thickness dimension that changes in response to changes in a magnetic field. A magnet generates the magnetic field, which changes in response to rotation of the rotatable member.

A hub is provided for a human-powered vehicle. The hub comprises a hub axle, a hub body, a sprocket support structure, a detected part and a rotation detection sensor. The hub axle has a center axis. The hub body is rotatably disposed around the center axis. The sprocket support structure is rotatably disposed around the center axis to transmit a driving force to the hub body while rotating in a driving rotational direction around the center axis. The detected part is provided to the sprocket support structure. The rotation detection sensor is configured to detect the detected part to detect rotation of the sprocket support structure around the center axis and being disposed in the hub body.

The present disclosure is directed to systems and methods for estimating machine rotation state. The rotation state can include the rotation speed and/or angle as the machine rotates. In some implementations, an estimating machine rotation state system can receive image data, timestamped consecutively, from camera devices of a machine. The estimating machine rotation state system can generate optical flow vectors for the pixels of the image data and determine the hue and intensity of the pixels based on the optical flow vectors. Using the hues, intensities, and timestamps of the image data, the estimating machine rotation state system can generate an intensity plot over time. The estimating rotation states system can then determine a rotation speed of the machine based on the intensity plot. The estimating rotation states system can also determine a rotation angle of the machine by integrating the intensity plot over time.