A torque detector detects a torsional torque between a first shaft and a second shaft based on a torsional displacement of an elastic member coaxially connecting the first shaft and the second shaft. The torque detector includes a magnetic flux generation unit and a magnetic sensor. The magnetic flux generation unit rotates with rotation of the first shaft and includes a first pole and a second pole into and out of which lines of magnetic force enter and exit. The magnetic sensor rotates with rotation of the second shaft and includes a detection surface for detecting a magnetic flux or a magnetic flux density. The first pole and the second pole are arranged to face each other across the magnetic sensor.

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 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.

A method of adjusting the closing force of a door coupled to a door closer assembly having a bias element. The method includes determining the kinetic energy of the door without using the weight or other dimensions of the door. The determined kinetic energy is used to adjust the closing force of an electro-mechanical door closer that includes a spring and a motor. The door includes the use of one, some of, or all of an accelerometer, an angular position sensor, a time to close, a breaking torque, and a controller to identify values of acceleration, velocity, and/or position of the door. The identified values are provided to the controller, which is configured to calculate the kinetic energy of the door. The calculated kinetic energy is used to determine the closing velocity of the door closure to ensure proper operation of the door at the point of installation.

Provided is a dynamometer-system dynamo control device that can appropriately suppress the occurrence of resonance phenomena and can realize a no-load state, even in a case where an engine the inertia of which is unknown is connected. The dynamometer system comprises a dynamometer and a shaft torque meter. A dynamo control device 6 in the dynamometer system generates a torque current command signal on the basis of a torque detection signal and a torque command signal. The dynamo control device 6 comprises: a gain calculation unit 62 that multiplies the difference between the torque command signal and the torque detection signal by gain wATR and then by Ki; an integration operation unit 63 that integrates the output signal of the gain calculation unit 62; a high-pass filter 64 characterized by a response frequency wHPF; and a torque current command signal generation unit 65 that generates a torque current command signal by superimposing, onto the output signal of the integration operation unit 63, an output signal obtained by inputting the torque detection signal to the high-pass filter 64.

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 a printed circuit board (PCB) having a substrate and at least one strain measurement device which may be attached to the PCB.

A bicycle (10) includes a frame (25) having a bottom bracket (40), a crankset (35) attached to the bottom bracket (40), a pedal (50) coupled to the crankset (35) and operable to propel the bicycle (10) in response to a force acting on the pedal (50). The bicycle further includes a first bicycle component acted upon by the pedal (50) in response to the force, a second bicycle component coupled and responsive to the first bicycle component, and a power vector sensor (85) coupled to and positioned between the first bicycle component and the second bicycle component, and the power vector sensor (85) includes a sensor element (100) to sense a force transferred from the first bicycle component to the second bicycle component and indicative of the force acting on the pedal (50).

Provided is a dynamometer-system dynamo control device that can appropriately suppress the occurrence of resonance phenomena and can realize a no-load state, even in a case where an engine the inertia of which is unknown is connected. The dynamometer system comprises a dynamometer and a shaft torque meter. A dynamo control device 6 in the dynamometer system generates a torque current command signal on the basis of a torque detection signal and a torque command signal. The dynamo control device 6 comprises: a gain calculation unit 62 that multiplies the difference between the torque command signal and the torque detection signal by gain wATR and then by Ki; an integration operation unit 63 that integrates the output signal of the gain calculation unit 62; a high-pass filter 64 characterized by a response frequency wHPF; and a torque current command signal generation unit 65 that generates a torque current command signal by superimposing, onto the output signal of the integration operation unit 63, an output signal obtained by inputting the torque detection signal to the high-pass filter 64.