A ship's speed meter for measuring a speed relative to the water of a ship 10, the ship's speed meter including a wave transmitter 1 for emitting a sound wave toward a sea bottom 20, a wave receiver 2 for detecting a plurality of reflected waves, which are reflected waves of the sound wave having been emitted from the wave transmitter 1, reflected by a plurality of reflecting objects 30 positioned at different water depths, and an arithmetic processing unit 4 for calculating a ship's speed relative to the water of the ship 10 based on a frequency difference of the sound wave and the reflected wave. The arithmetic processing unit 4 obtains a change rate of a current velocity in a water depth direction by obtaining current velocities at a plurality of different water depths based on a frequency difference between the sound wave and the plurality of reflected waves, and calculates a current velocity at a water depth at which the change rate is smaller than or equal to a threshold value as the ship's speed relative to the water of the ship 10.

Examples of systems and methods for locating movable objects such as carts (e.g., shopping carts) are disclosed. Such systems and methods can use dead reckoning techniques to estimate the current position of the movable object. Various techniques for improving accuracy of position estimates are disclosed, including compensation for various error sources involving the use of magnetometer and accelerometer, and using vibration analysis to derive wheel rotation rates. Also disclosed are various techniques to utilize characteristics of the operating environment in conjunction with or in lieu of dead reckoning techniques, including characteristic of environment such as ground texture, availability of signals from radio frequency (RF) transmitters including precision fix sources. Such systems and methods can be applied in both indoor and outdoor settings and in retail or warehouse settings.

An inertial sensor unit includes a first board on which a plurality of inertial sensor modules are mounted, and a second board on which a processing circuit configured to process signals from a plurality of inertial sensor modules is mounted.

An inertial sensor unit includes a first board on which a plurality of inertial sensor modules are mounted, and a second board on which a processing circuit configured to process signals from a plurality of inertial sensor modules is mounted.

A speed monitoring device and a passenger conveying device. The speed monitoring device includes a transmission rotor disposed on a shaft side surface of a shaft of which the speed is to be measured and rotating with rotation of the shaft of which the speed is to be measured; an encoder having an input shaft, the input shaft of the encoder being connected to the transmission rotor and rotating with rotation of the transmission rotor; and a mounting bracket for securing the transmission rotor and the encoder to a position where they are to be mounted.

A speed monitoring device and a passenger conveying device. The speed monitoring device includes a transmission rotor disposed on a shaft side surface of a shaft of which the speed is to be measured and rotating with rotation of the shaft of which the speed is to be measured; an encoder having an input shaft, the input shaft of the encoder being connected to the transmission rotor and rotating with rotation of the transmission rotor; and a mounting bracket for securing the transmission rotor and the encoder to a position where they are to be mounted.

An approach to determining vehicle usage makes use of a sensor that provides a vibration signal associated with the vehicle, and that vibration signal is used to infer usage. Usage can include distance traveled, optionally associated with particular ranges of speed or road type. In a calibration phase, auxiliary measurements, for instance based on GPS signals, are used to determine a relationship between the vibration signal and usage. In a monitoring phase, the determined relationship is used to infer usage from the vibration signal.

An approach to determining vehicle usage makes use of a sensor that provides a vibration signal associated with the vehicle, and that vibration signal is used to infer usage. Usage can include distance traveled, optionally associated with particular ranges of speed or road type. In a calibration phase, auxiliary measurements, for instance based on GPS signals, are used to determine a relationship between the vibration signal and usage. In a monitoring phase, the determined relationship is used to infer usage from the vibration signal.

An inertial force sensor includes: an acceleration detection element; a temperature sensor that detects an ambient temperature of the acceleration detection element; a bridge circuit that processes an output signal from the acceleration detection element; an AD converter that converts an analog signal output from the bridge circuit into a digital signal, and outputs the digital signal; a calculation circuit that performs calculation on the output signal from the AD converter; and a storage that stores correction data for correcting a variation in the output signal from the AD converter due to a temperature change. The correction data are coefficients of a formula expressed by a calibration curve that is a quadratic or higher-degree curve, and the storage stores, as the correction data, the coefficients of the calibration curve of each of a plurality of patterns that differ between a predetermined temperature or more and less than the predetermined temperature.

An inertial force sensor includes: an acceleration detection element; a temperature sensor that detects an ambient temperature of the acceleration detection element; a bridge circuit that processes an output signal from the acceleration detection element; an AD converter that converts an analog signal output from the bridge circuit into a digital signal, and outputs the digital signal; a calculation circuit that performs calculation on the output signal from the AD converter; and a storage that stores correction data for correcting a variation in the output signal from the AD converter due to a temperature change. The correction data are coefficients of a formula expressed by a calibration curve that is a quadratic or higher-degree curve, and the storage stores, as the correction data, the coefficients of the calibration curve of each of a plurality of patterns that differ between a predetermined temperature or more and less than the predetermined temperature.