A method of calibrating a crank arm-mounted power meter includes receiving an angle measurement from a first sensor disposed on a crank arm, the angle measurement corresponding to an angular orientation of the crank arm. A predicted load measurement is then calculated based on the angle measurement and weight data for the crank assembly including the crank arm and stored in memory. A load measurement corresponding to a load on the crank arm is obtained and a zero offset value is then calculated by determining a difference between the predicted load measurement and the load measurement. Power calculation logic for determining power applied to the crank arm is then updated using the zero offset value.

A method for determining a cogging torque may include applying a substantially constant rotation torque to an output shaft of a motor without electrically energizing the motor; detecting, an angle of rotation of the output shaft of the motor at each of a plurality of angles of rotation; calculating an angular acceleration of the motor at each of the plurality of angles of rotation by second order differentiating the angle of rotation; calculating a measured torque value at each of the plurality of angles of rotation by multiplying the angular acceleration by a moment of inertia of a rotor in the motor; obtaining a measured torque waveform of the measured torque value at each of the plurality of angles of rotation as a function of the plurality of angles of rotation; and calculating a cogging torque waveform based on a frequency of the measured torque waveform.

A method includes obtaining an image of a feature machined in a component with an imaging device, determining, by a computing device, a quality of the feature in the component based on the image of the feature, and storing, by the computing device, an indication of the quality of the feature in combination with a unique identifier for the feature in a non-transitory computer-readable medium.

In order to easily and accurately measure the cogging torque of an electric motor, the present invention includes a dynamometer connected to an electric motor, a torque sensor adapted to measure the torque of the electric motor, and a cogging torque measurement motor for measuring the cogging torque of the electric motor, and is configured such that when measuring the cogging torque of the electric motor, the electric motor, the dynamometer, and the cogging torque measurement motor are connected.

In order to easily and accurately measure the cogging torque of an electric motor, the present invention includes a dynamometer connected to an electric motor, a torque sensor adapted to measure the torque of the electric motor, and a cogging torque measurement motor for measuring the cogging torque of the electric motor, and is configured such that when measuring the cogging torque of the electric motor, the electric motor, the dynamometer, and the cogging torque measurement motor are connected.

Techniques are described for collecting sensor data associated with a wheelchair and, based on the sensor data, determining metric(s) for a user of the wheelchair. Sensor(s) attached to, or in proximity to, the wheelchair may collect sensor data describing the wheelchair and/or its component(s), such as location, velocity, acceleration, direction of movement, orientations (e.g., pitch, yaw, roll), angular velocity of wheels, angular acceleration of wheels, and so forth. The sensor data may be analyzed to determine (e.g., fitness) metrics such as a caloric burn rate, a metabolic burn rate, and/or power expenditure of the user while the user is employing the wheelchair to exercise or otherwise move. The metric(s) and/or sensor data may be presented to the user through a user interface on a smartphone, tablet computer, wearable computer, or other device, to enable the user to monitor fitness metric(s) during use of the wheelchair.

The purpose of the present invention is to provide a device for controlling a dynamometer of a test system, wherein the device is capable of controlling shaft torque to a prescribed target torque while minimizing low-frequency-range resonance caused by viscous drag of a test piece. This test system is provided with a dynamometer joined to an engine via a coupling shaft, an inverter for supplying electric power to the dynamometer, a shaft torque meter for detecting the shaft torque produced in the coupling shaft, and a dynamometer-controlling device 6 for generating a torque-current command signal T2 that is sent to the inverter and is generated on the basis of a shaft torque detection signal T12 from the shaft torque meter. The dynamometer-controlling device 6 is provided with an integrator 62 for integrating the difference between the shaft torque detection signal 12 and a shaft torque command signal T12ref, and a phase lead compensator 63 for accepting an output signal from the integrator 62 as an input and performing a phase lead compensation process that uses constants (a1, b1) that are dependent on the viscous drag of the test piece. An output signal from the phase lead compensator 63 is used to generate the torque-current command signal T2.

A power meter for a bicycle includes a body having a torque input section and a torque output section, the body configured to transmit power between the torque input section and the torque output section. The power meter also includes an electronic device having one or more antennae configured to communicate a signal wirelessly.

A power measurement device, which may be mounted to an inside area of a crank arm, includes processing circuitry within a housing. The processing circuitry is coupled with strain gauges mounted on the crank arm, and produces a power value that is wireless transmitted to a separate display that may receive and display power measurements. The housing may include a mounted portion and a cantilever portion where the mounted portion houses the processing circuitry and the cantilever portion houses batteries supply energy for the processing circuitry and other features.

An oarlock-installation for a boat in which an oarlock is mounted on an upright pin for angular displacement about the pin during rowing of the boat, the oarlock-installation comprising a mechanism for deriving measurements of angular displacement of the oarlock from a datum angle about the pin during the rowing, a mechanism for deriving measurements of force exerted on the oarlock during the rowing, and a mechanism for deriving measurement of rowing power from the measurements of force and the measurements of angular displacement. The rowing-boat oarlock-installation may also comprises a power module, attached to the oarlock, which is responsive to rowing of the rowing-boat to derive force measurements in accordance with rowing forces exerted on the power module during the rowing.