A rotation detection device to solve the above-described problems includes: accelerometers installed to be spaced apart from each other at predetermined pitches around a rotating shaft of a rotary machine, the accelerometers detecting rotation vibration of the rotary machine and outputting vibration signals; and a signal processing unit that acquires the vibration signals from the accelerometers. The signal processing unit includes: an installation information acquisition means for acquiring installation radii of the accelerometers with respect to the rotating shaft; an analysis processing means for acquiring frequency responses and coherences for the vibration signals; a determination means for determining whether or not the coherences are greater than a predetermined threshold value; and a rotation period calculation means for calculating a rotation period of the rotating shaft from the frequency, the phase difference, the predetermined pitch, and the installation radii.

A monitoring device of a main spindle rotation speed in a machine tool displays a variation state of the rotation speed by a rotation speed variation unit using a display unit in the machine tool. The monitoring device includes a variation value setting unit, a drawing unit, a first display unit, and a settable range calculating unit. The settable range calculating unit is configured to calculate a settable range of a variation amplitude and a variation cycle based on a calculation formula. The calculation formula includes the variation cycle, a difference between a first rotation speed and a second rotation speed at mutually different timings among the rotation speeds varied relative to a reference rotation speed, an inertia of a rotating body, a rated output of a motor that drives a main spindle, and a usage proportion to the rated output of the motor.

A monitoring device of a main spindle rotation speed in a machine tool displays a variation state of the rotation speed by a rotation speed variation unit using a display unit in the machine tool. The monitoring device includes a variation value setting unit, a drawing unit, a first display unit, and a settable range calculating unit. The settable range calculating unit is configured to calculate a settable range of a variation amplitude and a variation cycle based on a calculation formula. The calculation formula includes the variation cycle, a difference between a first rotation speed and a second rotation speed at mutually different timings among the rotation speeds varied relative to a reference rotation speed, an inertia of a rotating body, a rated output of a motor that drives a main spindle, and a usage proportion to the rated output of the motor.

A monitoring device of a main spindle rotation speed in a machine tool displays a variation state of the rotation speed by a rotation speed variation unit using a display unit in the machine tool. The monitoring device includes a drawing unit, a variation position display unit, and a reduction effect index display unit. The drawing unit is configured to display a variation diagram that illustrates a relationship between a variation amplitude and a variation cycle of the rotation speed. The reduction effect index display unit is configured to display a reduction effect index on the variation diagram. The reduction effect index represents a reduction effect of chatter vibration. The reduction effect index is calculated based on a speed ratio that is a ratio of a rotation speed of one rotation before to a rotation speed at an identical rotation position of the main spindle at any given timing.

A monitoring device of a main spindle rotation speed in a machine tool displays a variation state of the rotation speed by a rotation speed variation unit using a display unit in the machine tool. The monitoring device includes a drawing unit, a variation position display unit, and a reduction effect index display unit. The drawing unit is configured to display a variation diagram that illustrates a relationship between a variation amplitude and a variation cycle of the rotation speed. The reduction effect index display unit is configured to display a reduction effect index on the variation diagram. The reduction effect index represents a reduction effect of chatter vibration. The reduction effect index is calculated based on a speed ratio that is a ratio of a rotation speed of one rotation before to a rotation speed at an identical rotation position of the main spindle at any given timing.

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.

Provided is a method of estimating a speed of a vehicle includes obtaining time domain acoustic data from an acoustic storage apparatus when the vehicle passes over a horizontally grooved road; calculating frequency domain acoustic data from the time domain acoustic data by using Fourier transformation; calculating, from the frequency domain acoustic data, a resonance frequency of sound generated between tires of the vehicle and horizontal groovings in the road; and estimating the speed when the vehicle passes over the horizontally grooved road by multiplying the resonance frequency by an interval of the horizontal groovings.

Provided is a method of estimating a speed of a vehicle includes obtaining time domain acoustic data from an acoustic storage apparatus when the vehicle passes over a horizontally grooved road; calculating frequency domain acoustic data from the time domain acoustic data by using Fourier transformation; calculating, from the frequency domain acoustic data, a resonance frequency of sound generated between tires of the vehicle and horizontal groovings in the road; and estimating the speed when the vehicle passes over the horizontally grooved road by multiplying the resonance frequency by an interval of the horizontal groovings.

A measurement system and a measurement method using the same are provided. Firstly, a measurement system is provided. The measurement system comprises a film, a sensor and a movement information calculator, wherein the film has a patterned structure layer, and the sensor is electrically isolated from and selectively in contact with the film. Then, the sensor directly contacts the patterned structure layer and generates a sensing signal during relative movement process between the sensor and the film. Then, the movement information calculator obtains at least one of a relative movement amount and a relative movement speed during the relative movement process according to the sensing signal.

A measurement system and a measurement method using the same are provided. Firstly, a measurement system is provided. The measurement system comprises a film, a sensor and a movement information calculator, wherein the film has a patterned structure layer, and the sensor is electrically isolated from and selectively in contact with the film. Then, the sensor directly contacts the patterned structure layer and generates a sensing signal during relative movement process between the sensor and the film. Then, the movement information calculator obtains at least one of a relative movement amount and a relative movement speed during the relative movement process according to the sensing signal.