METHOD OF DETECTING AND CALCULATING HEIGHT OF A JUMP

Abstract

The invention pertains to a method of detecting and calculating height of a jump performed by an individual, comprising the following steps:

A detection of a reception subsequent to the jump, this step comprising a sub-step of detecting a pressure spike of amplitude greater than a first threshold amplitude, within pressure measurements provided by a pressure sensor embedded aboard a watch worn on the wrist of the individual,

A calculation of a height of the jump by differencing a starting altitude corresponding to a last stable pressure measured before the pressure spike and a finishing altitude corresponding to a first stable pressure measured after the pressure spike via the pressure sensor, a stable pressure being defined as a pressure whose variations do not exceed 0.1 hectopascals for at least 2 seconds.

Claims

1. A method of detecting and calculating height of a jump performed by an individual, comprising the following steps: A detection of a reception subsequent to the jump, this step comprising a sub-step of detecting a pressure spike of amplitude greater than a first threshold amplitude, within pressure measurements provided by a pressure sensor embedded aboard a watch worn on the wrist of the individual, A calculation of a height of the jump by differencing a starting altitude corresponding to a last stable pressure measured before the pressure spike and a finishing altitude corresponding to a first stable pressure measured after the pressure spike via the pressure sensor, a stable pressure being defined as a pressure whose variations do not exceed 0.1 hectopascals for at least 2 seconds.

2. The method according to claim 1, in which the step of detecting a reception comprising a sub-step of detecting an acceleration spike of amplitude greater than a second threshold amplitude, on the basis of acceleration measurements provided by a three-axis accelerometer embedded aboard the watch, and a sub-step of comparing the instant associated with the acceleration spike and the instant associated with the pressure spike.

3. The method according to claim 2, in which the second threshold amplitude is greater than 2 g, where g is the acceleration of gravity at the Earth's surface.

4. The method according to claim 1, in which the first threshold amplitude is greater than 10 hectopascals.

Description

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] In a nonlimiting embodiment, the method METH according to the invention is implemented entirely by an electronic watch MT worn by an individual carrying out a jump. In a nonlimiting embodiment shown in FIG. 1, the watch MT comprises: [0023] a set of sensors CP, including an accelerometer CP_AC and a pressure sensor CP_PR (or altimeter) [0024] a memory MD for recording measurements carried out by the sensors CP. The measurements are advantageously recorded in the memory in a sliding manner, according to the FIFO (first in, first out) principle [0025] a microprocessor MP for processing the information contained in the memory MD [0026] digital or analogue display means MA, for displaying the results of the calculations carried out by the microprocessor MP [0027] mechanical, electronic or touch-based means of activation MC, of the sensors CP, of the memory MD, of the microprocessor MP and of the display means MA, making it possible to trigger the method PR.

[0028] FIG. 2 shows a curve representing the pressure PR measured by the pressure sensor CP_PR of the watch MT as a function of the time t, and in particular during four phases P.sub.1, P.sub.2, P.sub.3 and P.sub.4.

[0029] In the first phase P.sub.1, the individual is in contact with the ground. During this first phase, the pressure PR.sub.d measured by the pressure sensor CP_PR is substantially constant. This pressure makes it possible to calculate a so-called starting altitude AT.sub.d. Next, the individual takes off from the ground and rapidly goes into free fall, this corresponding to the second phase P.sub.2. Thereafter, the individual enters the water (they are received), and then swims so as to exit the water, this corresponding to the third phase P.sub.3. The beginning of the third phase P.sub.3 is recognizable by virtue of the pressure spike PC.sub.PR visible on the first curve. Finally, in a fourth phase P.sub.4, the individual exits the water and is again in contact with the ground. During this fourth phase P.sub.4, the pressure PR.sub.a measured by the pressure sensor CP_PR is substantially constant. This pressure makes it possible to calculate a so-called finishing altitude AT.sub.a.

[0030] A first step of the method METH according to the invention consists in detecting that a jump has been performed (step METH_Dr in FIG. 3). More particularly, the detection step METH_Dr comprises a first sub-step METH_Dr_PC.sub.PR consisting in detecting a pressure spike PC.sub.PR in the measurements provided by the pressure sensor CP_PR. Indeed, when a jump is performed, a pressure spike PC.sub.PR is observed at the instant corresponding to the individual's reception on the ground. When such a spike PC.sub.PR is detected, it is compared with a threshold value beyond which it is decided that the spike PC.sub.PR does indeed correspond to a reception on the ground following a jump.

[0031] In one embodiment, to confirm that this pressure spike PC.sub.PR does indeed correspond to a reception following a jump, the detection step METH_Dr also comprises a second sub-step METH_Dr_PC.sub.AC consisting in detecting an acceleration spike PC.sub.AC in the measurements provided by the accelerometer CP_AC. Such an acceleration spike PC.sub.AC ought to be logged at an instant substantially identical to that at which the pressure spike PC.sub.PR was detected. The instants corresponding to the pressure spike PC.sub.PR and to the acceleration spike PC.sub.AC are therefore compared. If the norm of the difference between these instants is less than a threshold value, for example 0.5 seconds, then it is decided that the spikes PC.sub.PR, PC.sub.AC do indeed correspond to a reception on the ground following a jump.

[0032] A second step of the method METH according to the invention consists in calculating the height Ht of the jump (step METH_Ht). Accordingly, the finishing altitude AT.sub.a is deducted from the starting altitude AT.sub.d. It is noted that the starting altitude AT.sub.d is calculated by means of the last stable pressure PR.sub.d measured before reception, that is to say the stable pressure logged during the first phase P.sub.1. The finishing altitude AT.sub.a is calculated by means of the first stable pressure PR.sub.a measured after reception, that is to say the stable pressure logged during the fourth phase P.sub.4.

[0033] Of course, the present invention is not limited to the example illustrated but is subject to diverse variants and modifications which will be apparent to the person skilled in the art.