An apparatus for measuring velocities of projectiles launched from firearms is disclosed. The apparatus includes a stationary clamp arm and a movable clamp arm works in concert with the stationary clamp arm for clamping the apparatus to a firearm. A thumb screw is employed to secure the movable clamp arm and the stationary clamp arm to the firearm. A sensor module, which is integrated to the stationary clamp, includes a first and second sensor coils, a first magnet adjacent to the first sensor coil, and a second magnet adjacent to the second sensor coil.

The present disclosure relates to a system for verification of the speed of crosshead travel in a materials testing device. A linear displacement device is mounted on the crosshead of the materials testing device. The linear displacement device measures the displacement of the crosshead during the test. A timer interval counter measures the time of travel of the crosshead during the test. This measurements allow for accurate calculation of the speed of the crosshead travel.

The present disclosure relates to a system for verification of the speed of crosshead travel in a materials testing device. A linear displacement device is mounted on the crosshead of the materials testing device. The linear displacement device measures the displacement of the crosshead during the test. A timer interval counter measures the time of travel of the crosshead during the test. This measurements allow for accurate calculation of the speed of the crosshead travel.

A conversion section converts a change in signal information outputted from a vibration detector provided on a structural body from the change in the function of time into the change in the function of the distance between a moving object that moves on the structural body and the vibration detector. An attenuation characteristic calculation section calculates an attenuation characteristic of the structural body based on the signal information so converted as to represent the change in the function of the distance.

A conversion section converts a change in signal information outputted from a vibration detector provided on a structural body from the change in the function of time into the change in the function of the distance between a moving object that moves on the structural body and the vibration detector. An attenuation characteristic calculation section calculates an attenuation characteristic of the structural body based on the signal information so converted as to represent the change in the function of the distance.

A muzzle-mounted chronograph for measuring velocities of projectiles launched from firearms. The chronograph includes a sensor module and a controller. The sensor module includes a first and second coils and a device for applying a stable magnetic field to the first and second coils. The controller determines a velocity of a projectile passing by the first and second coils based on detected variations in magnetic fields at the first and second coils.

A muzzle-mounted chronograph for measuring velocities of projectiles launched from firearms. The chronograph includes a sensor module and a controller. The sensor module includes a first and second coils and a device for applying a stable magnetic field to the first and second coils. The controller determines a velocity of a projectile passing by the first and second coils based on detected variations in magnetic fields at the first and second coils.

In an exercise support device of the present invention, acceleration signals in three axis directions including vertical, longitudinal, and lateral directions corresponding to the motion of a user performing exercise of cyclically moving feet are obtained, and a first maximum value in one cycle of a foot movement in the vertical acceleration signal is obtained. Subsequently, a search is made for first and second change points related to foot landing and takeoff motions in a composite acceleration signal obtained by combining acceleration signals in at least two axis directions, in forward and backward directions of the time point of a second maximum value of the composite acceleration signal, within the cycle. Then, a time period between the first and second change points is obtained as a change point interval, and a foot landing period while exercising is calculated based on the first maximum value and the change point interval.

In an exercise support device of the present invention, acceleration signals in three axis directions including vertical, longitudinal, and lateral directions corresponding to the motion of a user performing exercise of cyclically moving feet are obtained, and a first maximum value in one cycle of a foot movement in the vertical acceleration signal is obtained. Subsequently, a search is made for first and second change points related to foot landing and takeoff motions in a composite acceleration signal obtained by combining acceleration signals in at least two axis directions, in forward and backward directions of the time point of a second maximum value of the composite acceleration signal, within the cycle. Then, a time period between the first and second change points is obtained as a change point interval, and a foot landing period while exercising is calculated based on the first maximum value and the change point interval.

Embodiments of the present disclosure provide a method and device for detecting a speed of an obstacle, a computer device, and a storage medium. The method includes: calculating at least two real-time speeds corresponding to the obstacle by using a multi-frame difference algorithm according to multi-frame data acquired by a sensor in a preset time window; calculating at least two speed statistic values corresponding to the obstacle according to the at least two real-time speeds; mapping each of the at least two speed statistic values to a corresponding static probability according to a mapping relationship between speed statistic values and static probabilities, to obtain at least two static probabilities; and fusing the at least two static probabilities to obtain a fused static probability of the obstacle, and determining the speed of the obstacle according to the fused static probability.