A device of or attached to a roller body determines a rotational frequency of the roller body (or other object) rotating about an axis of rotation includes an acceleration sensor that detects an acceleration signal of an acceleration in a first direction extending in a radial or tangential direction to the axis of rotation of the roller body; and an electronic processing unit and configured to low-pass and high-pass, particularly adaptively high-pass filter, the detected acceleration signal, perform a derivation, with respect to time, of the filtered signal, optimize the signal with a subsequent absolute-amount generation and with moving averaging, and ascertain a frequency of the filtered acceleration signal, which corresponds to the rotational frequency of the roller body.

A device of or attached to a roller body determines a rotational frequency of the roller body (or other object) rotating about an axis of rotation includes an acceleration sensor that detects an acceleration signal of an acceleration in a first direction extending in a radial or tangential direction to the axis of rotation of the roller body; and an electronic processing unit and configured to low-pass and high-pass, particularly adaptively high-pass filter, the detected acceleration signal, perform a derivation, with respect to time, of the filtered signal, optimize the signal with a subsequent absolute-amount generation and with moving averaging, and ascertain a frequency of the filtered acceleration signal, which corresponds to the rotational frequency of the roller body.

A system and method for estimating a velocity of a vehicle, including obtaining readings of at least one inertial sensor that is attached to the vehicle, calculating a time difference between a time when an irregularity is sensed in a first location of the vehicle and a time when the irregularity is sensed in a second location of the vehicle, and calculating the velocity of the vehicle based on the time difference.

A system and method for estimating a velocity of a vehicle, including obtaining readings of at least one inertial sensor that is attached to the vehicle, calculating a time difference between a time when an irregularity is sensed in a first location of the vehicle and a time when the irregularity is sensed in a second location of the vehicle, and calculating the velocity of the vehicle based on the time difference.

A monitoring system for a speed determination system in an aircraft is disclosed. A method, which may be implemented by a computer program, of monitoring a speed determination system for an aircraft is also disclosed. The speed determination system includes a first speed measurement system and a second speed measurement system and the second speed measurement system is associated with a predetermined behaviour characteristic. The monitoring system includes a processor arranged to receive speed data provided by the speed determination system and to perform a correspondence determination process comprising processing the received speed data to determine whether a correspondence condition is satisfied, the correspondence condition having a correspondence between the received speed data and the predetermined behaviour characteristic of the second speed measurement system. In response to determining that the correspondence condition is satisfied, determine that the first speed measurement system is in an error condition.

A movable member coupled to a displacement detector via a void is disposed with respect to a fixed member to which a coil is fixed. By disposing the coil in a closed loop magnetic circuit including a permanent magnet, the movable-side member, and the fixed member, a Lorentz force for moving the movable-side member in the axial direction is generated.

A movable member coupled to a displacement detector via a void is disposed with respect to a fixed member to which a coil is fixed. By disposing the coil in a closed loop magnetic circuit including a permanent magnet, the movable-side member, and the fixed member, a Lorentz force for moving the movable-side member in the axial direction is generated.

Disclosed are a portable surface characteristics measurement device and a control method thereof. The portable surface characteristics measurement device includes: a roughness sensor configured to convert a signal sensed from a surface of an object during movement of the portable surface characteristics measurement device on the surface of the object into an electric vibration signal; a movement measurement sensor configured to measure a movement physical quantity of the portable surface characteristics measurement device; and a processor configured to change a sampling interval depending on the measured movement physical quantity, and sample the vibration signal in real time, wherein the processor is configured to perform Fourier transform on the sampled vibration signal, and identify a peak frequency band shown in the Fourier-transformed vibration signal as surface roughness information of the object.

Disclosed are a portable surface characteristics measurement device and a control method thereof. The portable surface characteristics measurement device includes: a roughness sensor configured to convert a signal sensed from a surface of an object during movement of the portable surface characteristics measurement device on the surface of the object into an electric vibration signal; a movement measurement sensor configured to measure a movement physical quantity of the portable surface characteristics measurement device; and a processor configured to change a sampling interval depending on the measured movement physical quantity, and sample the vibration signal in real time, wherein the processor is configured to perform Fourier transform on the sampled vibration signal, and identify a peak frequency band shown in the Fourier-transformed vibration signal as surface roughness information of the object.

Driving behavior for a particular driver may be gathered and analyzed over a time period, such as a year or a duration of the driver's employment at a particular employer. The driving behavior is received by a server from a positioning device as multiple streams of position data at different time stretches throughout the time period, each stream of position data associated with a route of a plurality of routes driven by at least one vehicle. The server generates speed data from the streams of position data and compares the speed data to retrieved speed limit data for those routes. The server generates a report with at least a speeding percentage value corresponding to how often the driver was speeding while driving during the time period. The report is then sent to the driver's computing device.