The present disclosure relates to the estimation of a velocity of a first object using accelerometer signals, indicating an acceleration of the first object and/or a second object coupled to a first object. To this end, a characteristic frequency in the accelerometer signal spectrum may be determined, preferably by applying a parametric model or by performing a spectrum analysis, and used as a basis to estimate the velocity of the first object based on the determined characteristic frequency. The characteristic frequency may be determined by identifying the frequency having the maximum spectral amplitude or by identifying the fundamental frequency or a particular harmonic in the spectrum.

The present disclosure relates to the estimation of a velocity of a first object using accelerometer signals, indicating an acceleration of the first object and/or a second object coupled to a first object. To this end, a characteristic frequency in the accelerometer signal spectrum may be determined, preferably by applying a parametric model or by performing a spectrum analysis, and used as a basis to estimate the velocity of the first object based on the determined characteristic frequency. The characteristic frequency may be determined by identifying the frequency having the maximum spectral amplitude or by identifying the fundamental frequency or a particular harmonic in the spectrum.

A human-powered vehicle control device includes an electronic controller that controls a motor. The motor assists in propulsion of a human-powered vehicle including a transmission configured to change, in steps, a first ratio of a rotational speed of a drive wheel to a rotational speed of a rotary body to which human drive force is input. The controller controls the motor in a first control state if the first ratio is changed by only one step during a predetermined period or a signal is received for changing the first ratio by one step during the predetermined period. The controller controls the motor in a second control state that differs from the first control state if the first ratio is changed by at least two steps during the predetermined period or a signal is received for changing the first ratio by at least two steps during the predetermined period.

The present disclosure relates to a system for detecting characteristics of a moving element. The system may include a tubular housing having a tubular first portion having a first end and a second end, with the first end forming an input port and the second end forming an output port. A source of wireless electromagnetic energy projects a wireless electromagnetic energy signal, travelling in a first direction, into the input port and through an interior area defined by the tubular first portion. A signal processing subsystem detects at least one characteristic of the signal after the signal is reflected back to the first end after having interacted with the element as the element moves past the output port of the housing.

The present disclosure relates to a system for detecting characteristics of a moving element. The system may include a tubular housing having a tubular first portion having a first end and a second end, with the first end forming an input port and the second end forming an output port. A source of wireless electromagnetic energy projects a wireless electromagnetic energy signal, travelling in a first direction, into the input port and through an interior area defined by the tubular first portion. A signal processing subsystem detects at least one characteristic of the signal after the signal is reflected back to the first end after having interacted with the element as the element moves past the output port of the housing.

Techniques are provided which may be implemented using various methods and/or apparatuses in a mobile GNSS device to compensate for arm swing. An example of an method for compensating for arm swing according to the disclosure includes determining an arm swing signal, such that the arm swing signal is approximately sinusoidal with a period of approximately T seconds, determining a position signal measurement period, receiving a plurality of positioning signals at intervals corresponding to the position signal measurement period, and determining current position information based on the plurality of positioning signals.

Techniques are provided which may be implemented using various methods and/or apparatuses in a mobile GNSS device to compensate for arm swing. An example of an method for compensating for arm swing according to the disclosure includes determining an arm swing signal, such that the arm swing signal is approximately sinusoidal with a period of approximately T seconds, determining a position signal measurement period, receiving a plurality of positioning signals at intervals corresponding to the position signal measurement period, and determining current position information based on the plurality of positioning signals.

A system and method for measuring motion properties of a movable object, such as a sporting device, wherein the movable object has an embedded magnetized unit creating a magnetic field. A measurement device, having a first magnetic field sensor positioned a known distance away from a second magnetic field sensor, is positioned in the vicinity of the movable object's trajectory, whereby the first and second magnetic field sensors output signals when the movable object passes within their respective proximities. A control module, that is responsive to the output signals created by the magnetic field sensors, is configured to record the times of output signal events. The control module is further configured to calculate motion properties, such as the speed and rate of spin, of the movable object based upon the recorded times of various sensor output events and the known distance between the first and second magnetic field sensors.

A system and method for measuring motion properties of a movable object, such as a sporting device, wherein the movable object has an embedded magnetized unit creating a magnetic field. A measurement device, having a first magnetic field sensor positioned a known distance away from a second magnetic field sensor, is positioned in the vicinity of the movable object's trajectory, whereby the first and second magnetic field sensors output signals when the movable object passes within their respective proximities. A control module, that is responsive to the output signals created by the magnetic field sensors, is configured to record the times of output signal events. The control module is further configured to calculate motion properties, such as the speed and rate of spin, of the movable object based upon the recorded times of various sensor output events and the known distance between the first and second magnetic field sensors.

A method, system, and apparatus for determining the location of a tool traveling down a wellbore by measuring a first borehole magnetic anomaly with respect to time at two known locations on a tool, comparing the time difference between the two measurements, then calculating the velocity of the tool based on the comparison, then further calculating the distance traveled by the tool in the wellbore based on the velocity calculation, then executing a series of commands at a predetermined location in the wellbore.