A system configured for monitoring the operation status of an electric machine; a mobile phone therefor and server-based system using the same. The system includes a portable unit, adapted for free movement around the electric machine; an airborne acoustics sensor, adapted for measuring acoustic data produced by the electric machine at a first position in a path of the free movement; a magnetic field sensor, adapted for measuring magnetic field data produced by the electric machine at a second position in the path of the free movement; and a processing unit, adapted for calculating the operation status of the electric machine based on the acoustic data from the airborne acoustics sensor and the magnetic field data from the magnetic field sensor; wherein: the airborne acoustics sensor and the magnetic field sensor are integrated with the portable unit.

In an angular velocity sensor, when a width of a detection frequency band is set to f1 [Hz], a resonance frequency in a first rotational vibration mode in which a base portion rotates and vibrates around a detection axis with respect to fixing units in association with the deformation of beam portions is set to f2 [Hz], a detuning frequency is set to f3 [Hz], and a resonance frequency in a second rotational vibration mode, having a phase opposite to that of the first rotational vibration mode, in which the base portion rotates and vibrates around the detection axis with respect to the fixing units in association with the deformation of the beam portions is set to f4, a relation of f1<f2<f3<f4 or a relation of f1<f2<f4<f3 is satisfied.

In an angular velocity sensor, when a width of a detection frequency band is set to f1 [Hz], a resonance frequency in a first rotational vibration mode in which a base portion rotates and vibrates around a detection axis with respect to fixing units in association with the deformation of beam portions is set to f2 [Hz], a detuning frequency is set to f3 [Hz], and a resonance frequency in a second rotational vibration mode, having a phase opposite to that of the first rotational vibration mode, in which the base portion rotates and vibrates around the detection axis with respect to the fixing units in association with the deformation of the beam portions is set to f4, a relation of f1<f2<f3<f4 or a relation of f1<f2<f4<f3 is satisfied.

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 angular velocity sensor includes fixing units, a base portion, beam portions that support the base portion with respect to the fixing units, driving vibrating arms connected to the base portion, and detection vibrating arms connected to the base portion. When a width of a detection frequency band is set to f1 [Hz], a resonance frequency in a rotational vibration mode in which the base portion rotates and vibrates around a detection axis with respect to the fixing units in association with the deformation of the beam portions is set to f2 [Hz], and a detuning frequency is set to f3 [Hz], the relation of f1<f2<f3 is satisfied.

A mixer nozzle assembly for mixing fluid introduced into a tank having a tank volume therein. The mixer nozzle assembly includes a stationary body and a rotatable body mounted on the stationary body for rotation about an axis in a predetermined direction. The fluid flows through the stationary body to the rotatable body and exits into the tank volume via one or more outlet apertures, thereby causing the rotatable body to rotate in the predetermined direction about the axis. The mixer nozzle assembly also includes a governor subassembly for controlling a speed of rotation of the rotatable body in the predetermined direction about the axis.

A mixer nozzle assembly for mixing fluid introduced into a tank having a tank volume therein. The mixer nozzle assembly includes a stationary body and a rotatable body mounted on the stationary body for rotation about an axis in a predetermined direction. The fluid flows through the stationary body to the rotatable body and exits into the tank volume via one or more outlet apertures, thereby causing the rotatable body to rotate in the predetermined direction about the axis. The mixer nozzle assembly also includes a governor subassembly for controlling a speed of rotation of the rotatable body in the predetermined direction about the axis.

Systems, methods, devices and computer-readable storage mediums are disclosed for device state estimation under pedestrian motion with swinging limb. In some implementations, a method comprises: determining, by a device, that the device is attached to a swinging limb based on a sensor signal; determining, by the device, a rotational velocity component due to the swinging limb based on the sensor signal and limb parameters; estimating, by the device, device velocity; and determining, by the device, user velocity based on the device velocity and the rotational velocity component.

An inertial measurement unit includes: a sensor unit including an inertial sensor, a case accommodating the inertial sensor, and a first fixing part having the case fixed thereto; an elastic member having a first elastic member mainly damping a vibration at a predetermined frequency in a first direction and a second elastic member mainly damping a vibration at a predetermined frequency in a second direction that is different from the first direction; a second fixing part where the sensor unit and the elastic member are arranged; and a fixing member fixing the sensor unit and the elastic member to the second fixing part.

An inertial measurement unit includes: a sensor unit including an inertial sensor, a case accommodating the inertial sensor, and a first fixing part having the case fixed thereto; an elastic member having a first elastic member mainly damping a vibration at a predetermined frequency in a first direction and a second elastic member mainly damping a vibration at a predetermined frequency in a second direction that is different from the first direction; a second fixing part where the sensor unit and the elastic member are arranged; and a fixing member fixing the sensor unit and the elastic member to the second fixing part.