Portable object, in particular a portable watch, equipped with a device for detecting the passage of a Kármán line, and detection method

Abstract

To provide a portable object capable of detecting with sufficient accuracy the crossing of the Karman line by a rocket.SOLUTION: A watch 2 includes a memory 4 and a detection device 6. The detection device 6 includes: an acceleration sensor 8 capable of measuring an acceleration vector of the watch in a three-dimensional coordinate frame linked to the watch; and an electronic unit 12 that is configured to be able to process measurement results supplied by the acceleration sensor. The electronic unit 12 is configured to be able to detect, solely by means of the watch on board the rocket, crossing of the Karman line by the rocket. Crossing of the Karman line by the watch is detected by the detection device on the basis of intermittent measurements performed by the acceleration sensor from take-off of the rocket until the crossing of the Karman line defined before space flight, and on the basis of at least one corresponding reference value stored in the memory.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a space-related portable object, in particular a portable timepiece (e.g. wristwatch, pocket watch) for astronauts or other individuals traveling in space using rockets or space shuttles. More specifically, the present invention relates to a portable object, in particular a portable timepiece, equipped with a detection device for detecting the passage of the Kármán line, and to a method for detecting the passage of the Kármán line. The Kármán line defines the boundary between the traditional Earth's atmosphere and space. The Kármán line is typically taken to correspond to an altitude of 100 km. However, this altitude varies according to different organizations, in particular within the range of 85 km to 110 km. The Kármán line is also the boundary within which a spacecraft must fly substantially at an orbital speed capable of maintaining an orbit around the Earth in order to maintain flight. [Background technology]

[0002] A variety of watches have been worn by astronauts on space missions. Some watches worn by astronauts are selected for their robustness and accuracy, without having any specific function for space flights or missions. However, there are other watches, particularly electronic watches, that provide specific functions that are useful for space missions. These specific functions are typically related to measuring time, such as countdowns and alarms. Summary of the Invention [Problem to be solved by the invention]

[0003] The object of the invention is to provide a portable object, in particular a portable watch, capable of detecting with sufficient accuracy the passage of the Kármán line by at least a given type of rocket (also called a type of launch vehicle in the technical field of space flight) on which the portable watch is on board, and / or by a rocket or space shuttle (hereinafter all of which will be referred to as "rocket").

[0004] In particular, one of the objects of the invention is to provide a portable item, in particular a portable watch, that allows autonomous detection of the passage of Kármán lines during a space flight, this detection being carried out in particular without receiving external communication signals, therefore without using a Global Positioning System (GPS), and without receiving signals from a rocket related to real-time data of the space flight of interest, during which the passage of Kármán lines by the rocket is intended to be detected with the aid of a portable item on board said rocket.

[0005] Another object of the invention is to provide a portable object, in particular a watch, capable of detecting its own passage through a Kármán line with sufficient accuracy, comprising relatively limited, but precise and space-saving technical means which can be easily integrated into the portable object, in particular the watch. [Means for solving the problem]

[0006] The present invention relates to a portable object that can be worn by a user, comprising a memory, a time base and a detection device formed by an acceleration sensor capable of measuring the acceleration vector of the portable object along three orthogonal axes defining a coordinate frame linked to the portable object (i.e. capable of measuring the acceleration vector of the portable object in the three-dimensional coordinate frame of the portable object), and an electronic unit configured to process the measurement results provided by the acceleration sensor. The detection device, in conjunction with a memory, is configured to be able to autonomously detect, during a space flight of a given type of rocket, the passage of a Kármán line by the portable object on board the rocket, and the Kármán line L K is the given altitude H D , or an altitude H that can be selected by the user, either directly or via another selectable spatial variable. SThe electronic unit calculates the passage of the Kármán line by the rocket from the take-off of the rocket to the Kármán line L K and measuring the acceleration vector of the portable object by the acceleration sensor until the portable object passes through a predetermined reference value stored in the memory before the takeoff or a correction factor F that is determined in advance and stored in the memory before the takeoff. C and the reference value calculated in the electronic unit by the Karman line L before the takeoff. K Altitude selected by the user for H S The predetermined reference value and the correction coefficient F C is the given altitude H D The electronic unit is configured to calculate the change in a comparative distance over time based on the intermittent measurements of the acceleration vector of the portable article and to compare this comparative distance over time with the predetermined or calculated reference value to be able to detect the passage of a Kármán line by the portable article, and thus the rocket.

[0007] The portable article according to the invention is therefore remarkable in that it is designed to be able to autonomously detect the passage of the Kármán line by said portable article on board a given type of rocket, with the only technical means required being a detection device comprising a memory, an acceleration sensor capable of measuring the components of the acceleration vector relative to said portable article in a coordinate frame linked to said portable article, and an electronic unit for processing the measurements provided by the acceleration sensor. The portable article according to the invention therefore does not require a three-axis gyrometer made by a microelectromechanical system (also called "MEMS"), which can indeed be small, but is typically not very accurate and in any case not sufficiently accurate to be able to accurately detect the change in orientation of the coordinate frame specific to said acceleration sensor during the space flight and to be able to determine the vertical component of the acceleration of the rocket's motion at any time between take-off and the passage of the Kármán line and thus to determine its altitude over time. The invention therefore makes it possible to avoid the problems associated with small gyrometers, which are relatively inaccurate and are not able to provide sufficiently accurate measurements of the angular velocity of the portable article to determine the changes in its temporary orientation and position in space, in particular its altitude. On the other hand, relatively inexpensive acceleration sensors having small dimensional configurations of the same order of magnitude can provide accurate measurements of acceleration along three axes.

[0008] In a main embodiment, the portable item is a portable watch.

[0009] In a preferred embodiment, the acceleration sensor is a Microelectromechanical System (also known by the acronym "MEMS"). Such a sensor is small enough to be easily integrated into a wristwatch. However, despite its small size, it can be very accurate. By choosing such an acceleration sensor, the predetermined reference value is also advantageously determined based on the nominal motion acceleration of the rocket. The term "motion acceleration" is understood to mean an acceleration corresponding to the time derivative of the velocity, which always defines a vector tangential to the trajectory of the rocket, and thus of the portable object, in space, i.e. a vector in the same direction as the temporary direction vector of the rocket. The term "nominal" is understood to mean a value given in the specifications of the type of rocket or of the particular rocket in question. The value is therefore a theoretical value, in the context of the present invention, in this case time-dependent, predicted for the rocket in question, resulting from the design of that rocket and the planning of the space flight with that rocket, in particular from launch to the crossing of the Kármán line. However, MEMS type accelerometers do not provide the motion acceleration, but the intrinsic acceleration, which does not make it possible to determine the motion acceleration, in particular the vertical component of such acceleration, which is primarily taken into account when determining the momentary altitude of the rocket, in the absence of sufficiently accurate data on the momentary orientation of the rocket in space. The present invention provides a remarkable approach to this problem, as will become apparent from the detailed description that follows.

[0010] In one preferred alternative embodiment, the detection device is configured such that the comparative distance is calculated based on the norm of an acceleration vector measured by the acceleration sensor and given components in the coordinate frame linked to the portable article, and the electronic unit is configured to be able to calculate these norms. More specifically, the acceleration sensor gives an acceleration vector in a native coordinate frame, but the norm of the acceleration vector is coordinate frame independent, i.e. it is invariant regardless of the spatial orientation of the coordinate frame in which this acceleration vector is given. Thus, the uncertainty of the orientation of the measurement coordinate frame in the acceleration measurement does not matter. This preferred alternative embodiment is very advantageous, since it overcomes the fact that the coordinate frame linked to the portable article, i.e. the coordinate frame defined by the acceleration sensor fixed relative to the portable article, has an orientation relative to the coordinate frame of the Earth, which orientation varies during the space flight between the launch site of the rocket and the Kármán line, in particular because the rocket does not follow a vertical linear trajectory. Also, the orientation of the portable article may change over time relative to the rocket as a result of the movement of the user wearing it.

[0011] In one advantageous alternative embodiment, the correction factor is equal to the predetermined reference value divided by the given altitude.

[0012] In a typical embodiment, the predetermined reference value is determined based on at least one theoretical function of a spatial variable associated with the rocket from take-off of the rocket to the given altitude of the Kármán line.

[0013] In an alternative general embodiment, the portable object is configured to record the passage of the Kármán line in a protected portion of its memory, such that a user of the portable object cannot write to the protected portion.

[0014] The invention further relates to a method for detecting the passage of a Kármán line by a rocket of a given type carrying a portable object according to the invention, using the portable object according to the invention as claimed in claim 1. Alternative embodiments are described in the claims dependent on this claim 1.

[0015] In the following the invention will be explained in more detail by way of example and without being limited thereto with reference to the attached drawings, in which: [Brief description of the drawings]

[0016] [Figure 1] 1 shows a schematic representation of a watch according to the invention, comprising various electronic components forming the watch; [Diagram 2] It shows the trajectory (interrupted in the figure) that a rocket follows during its flight in space, from take-off until the crossing of the Kármán line, and the various variables related to the flight along this trajectory, which relate to the method according to the invention for detecting the crossing of the Kármán line, and its implementation in a detection device for detecting the crossing of the Kármán line, according to the main embodiment of the invention. [Diagram 3] 3 shows an enlarged view, enlarged compared to FIG. 2, of the vector sum of the various accelerations involved in the method of detecting the passage of a Kármán line according to the invention. The orthogonal axes Xt and Zt are parallel to the X- and Z-axes of FIG. 2 and have their origin at a point PS(t) on the trajectory TF(x) of the rocket of interest, which defines the altitude HF(t) and horizontal distance EH(t) of the rocket over time. [Figure 4] 1 shows theoretical curves of the motion acceleration of a particular type of rocket as a function of time. [Diagram 5] 1 shows a curve illustrating the inclination angle of a rocket over time, as measured during the flight of said rocket, and a theoretical curve for this inclination angle. [Figure 6] 4 shows a curve illustrating the theoretical altitude of the rocket over time. [Figure 7]7A-7D show, according to an alternative embodiment, different messages given to the user by the watch during a flight in space, and the detection of the passage of a Kármán line by the watch of the present invention, implementing the detection method of the present invention. [Figure 8] 8A and 8B show two messages to a user of a watch that can be displayed by the watch after it detects the passage of a Kármán line, in particular after the completion of a space flight or mission, according to one alternative embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, with reference to the drawings, an embodiment of a portable object according to the present invention, which is a portable watch, and an embodiment of a method for detecting the passage of a Kármán line by such a portable object, which is a main embodiment of the present invention, will be described.

[0018] In a typical embodiment, the watch 2 comprises a memory 4 and a detection device 6, which comprises an acceleration sensor 8 capable of measuring the acceleration vector of the watch in a three-dimensional coordinate frame 10 linked to the watch 2, and an electronic processing unit 12 (hereinafter also called "electronic unit") adapted to process the measurement results provided by the acceleration sensor 8. The watch 2 further comprises an electronic control unit 14, which is adapted in particular to activate the detection device 6 in response to the actuation of an outer control member. The watch 2 comprises various outer control members, in particular two push buttons 16 and 17 and a stem crown 18. It should be noted that the watch 2 can comprise tactile control means, in particular a tactile windshield covering the display means, which are provided for example for inputting data into the watch's memory 4 and / or for controlling the display of certain data by the display means, in particular before and after a space flight or mission. In a particular alternative embodiment shown in Figure 7A, the watch 2 comprises an analog display 34 formed by hands associated with a scale, and a digital display 30 formed by an electronic display module forming the majority of the face of the watch 2. It should be noted that said hands can traditionally be used to represent time data, but can also be used to represent other things, for example to represent the current step in the detection method, to represent an event such as the crossing of the Kármán line, or to represent the correct progression or completion of a maneuver prior to a flight.

[0019] The electronic unit 12 calculates, at least for a given type of rocket, the Kármán line L K The passage of the Kármán line L can be detected by using only the portable watch 2 on board the rocket in conjunction with the acceleration sensor 8 and the memory 4. Therefore, during the space flight of the rocket, the detection is performed autonomously by the portable watch using the detection device of the portable watch. Kis the given altitude H D or user selectable altitude H, either directly or through the selection of another spatial variable S The term "given altitude" should be understood to mean an altitude that is predefined / predetermined by the watch manufacturer or any authorized person or company, and not by the user. However, if there are several given altitudes, they may be selectable by the user, i.e. the user may select one given altitude from several given altitudes.

[0020] Karman line L by rocket 22 with watch 2 on board K The passage of the acceleration vector can be detected by the detection device 6 on the basis of intermittent measurements of the acceleration vector of the watch made by the acceleration sensor 8 from the take-off of the rocket until the passage of the Kármán line and on a reference value corresponding to an altitude defined for the Kármán line. This reference value is recorded in the memory 4 of the watch before the space flight and is intended to be detected during the space flight by means of the watch on board the rocket when the rocket passes said altitude defined for the Kármán line. In the following, several alternative embodiments for defining and calculating the reference value are described. The watch comprises a time base enabling the sequential determination of the periods for performing the intermittent measurements of the acceleration vector. More generally, in the case of a portable article, the portable article comprises a time base adapted to determine the sequential periods and thus to enable the detection device to perform the intermittent measurements of the acceleration vector. In one alternative embodiment, the time base can be a unit separate from but associated with the detection device, thereby enabling in particular the intermittent activation of the acceleration sensor. In another alternative embodiment, the time base is integrated into the detection device. In one particular alternative embodiment, the time base is directly related to the acceleration sensor so that the measurement of the acceleration vector can be synchronized.

[0021] More specifically, the reference value is a predetermined reference value previously stored in the memory, or a correction coefficient F C , and the Kármán line L by the user K The altitude selected for H S The predetermined reference value and the correction factor are calculated in the electronic unit at a given altitude H D . The electronic unit 12 is arranged to be able to calculate the change in the comparative distance over time based on the intermittent measurements of the rocket's acceleration and to compare this comparative distance over time with a predetermined or calculated reference value, thereby making it possible to detect the passage of the Kármán line by the watch 2, and thus by the rocket 22. Advantageously, the reference value is recorded in the memory 4 when the watch is programmed, either "at the factory" or later, by means of a specific device arranged to provide this reference value to the watch. In a simpler alternative embodiment, the watch may be arranged to be able to input the reference value into the watch, i.e. into the memory 4, via a control member that the watch comprises.

[0022] In one advantageous alternative embodiment, the correction factor F C is the predetermined reference value at the given altitude H D It is equal to the value divided by.

[0023] In an alternative preferred embodiment, the predetermined reference value is the distance from the launch of the rocket to the Karman line L K The given altitude H corresponding to D is determined based on at least one theoretical function of spatial variables associated with the rocket.

[0024] In a first particular embodiment, the memory 4 stores a number of given altitudes H D j(j=1 to J), each of the predetermined reference values ​​being generally determined based on at least one theoretical function of spatial variables associated with the rocket of interest from launch to a corresponding given altitude H D j are each user selectable so that said comparison distance over time, calculated when the watch detects the passage of the Kármán line, can be compared to a corresponding predetermined reference value.

[0025] In a second particular embodiment, the memory 4 stores a number of given altitudes H D j (j=1 to J) C j (j=1 to J). Each correction coefficient F C j is detected automatically by the detection device or optionally by the user, who then detects the Kalman line L K The selected altitude H S , whereby the comparison distance over time, calculated when the watch detects the passage of the Kármán line, is calculated as a function of the selected correction factor and the selected altitude H S It is possible to compare the measured value with a reference value determined by

[0026] In an advantageous alternative embodiment of the second particular embodiment, the D j A plurality of predetermined reference values ​​are defined for each of the predetermined reference values, each of which is defined in a conventional manner based on at least one theoretical function of a spatial variable associated with the rocket of interest from the take-off of the rocket to a corresponding given altitude. C j are each a plurality of predetermined reference values ​​at a plurality of given altitudes H D j By virtue of the correction coefficients, the altitude of the Kármán line H, which is selectable and therefore variable, is SBy multiplying by , it is possible to obtain a reference value which can be compared in the electronic unit of the watch with a comparison distance given by the detection device during the space flight of the rocket in question, thus making it possible to detect the passage of the Kármán line by the watch and, thus, by the rocket.

[0027] In one preferred embodiment, the acceleration sensor 8 is formed by a micro-electromechanical system (MEMS).

[0028] In one preferred embodiment, when only one predetermined reference value is provided, the predetermined reference value is also determined based on the nominal motion acceleration of the rocket. When multiple reference values ​​are provided, each predetermined reference value is also determined based on a given altitude H corresponding to the Kármán line from the takeoff of the rocket. D It is based on the rocket's nominal acceleration up to 1000 rpm.

[0029] In the following, a method for detecting the passage of the Kármán line by a rocket using a watch according to the present invention is described. The following description makes it easier to understand exactly how the various variables and functions are defined and / or obtained and how they contribute in relation to the present invention. This detection method can be implemented by a watch according to the main embodiment described below.

[0030] The present invention relates to a method for determining the altitude of a rocket at a given altitude H during the space flight of the rocket. D , or the selected altitude H S , the Kármán line L of a given type of rocket 22 is defined by KThe present invention relates to a method for detecting the passage of a rocket, the detection being carried out by a portable object that can be worn by a user, the portable object being in particular a watch 2 on board the rocket and equipped with a memory 4, a time base and a detection device 6, the detection device 6 being formed by an acceleration sensor 8 and an electronic unit 12, the acceleration sensor 8 detecting a characteristic acceleration vector a of the watch in a three-dimensional coordinate frame 10 linked to the watch. M * The electronic unit 12 is configured to process the measurement results provided by the acceleration sensor 8, and the intrinsic acceleration vector a M * is the acceleration a of the motion vector of this watch in the first approximation of the rocket. * From the gravitational acceleration vector a at any instant / any time t E * minus . Note that in this text we use an asterisk (*) to denote vectors, and in figures 2 and 3 we use the traditional method of denoting vectors with arrows over the variables of interest. In general, the intrinsic acceleration vector of a watch is equal to the vector sum of the forces acting on the watch, excluding gravity, divided by its mass. That is, the intrinsic acceleration of an object is the acceleration that this object experiences with respect to an observer when it is in free fall.

[0031] The detection method includes a preliminary stage for a portable object aboard a rocket for a planned space flight, which stage includes the following preliminary steps: (A) Determine time 0 from the launch of the rocket, at least the Kármán line L K The given altitude H corresponding to D The nominal acceleration A of the rocket 22 until the passage of N(t) as a function of time t, where the nominal motion acceleration is a scalar value (norm of the nominal motion vector acceleration) with units equal to the gravity of the Earth (hence this dimensionless scalar value corresponds to the norm of the nominal motion vector acceleration divided by the norm of the gravity of the Earth, see FIG. 4). (B) A given altitude H from the takeoff of the rocket D The theoretical inclination angle θ relative to the horizontal plane for a given type of rocket as a function of time t until at least one pass of T This is the step of preparing (t) (see FIG. 5). (C) A given altitude H from the takeoff of a rocket D The theoretical flight time T of a given type of rocket until the passage of K This is a step of preparing or determining. (D) the theoretical specific acceleration A for a given type of rocket as a function of time based on said nominal kinetic acceleration and said theoretical tilt angle. PT (t), the value of which, in units equal to the gravity of the Earth, is defined by the following formula:

[0032] TIFF0007675888000001.tif14170

[0033] (E) Time 0 (t=0) corresponding to the rocket takeoff and time T corresponding to the theoretical flight time K Theoretical specific acceleration A between PT (t), or the theoretical specific acceleration minus the norm of gravitational acceleration, MT by numerical and / or mathematical means, MT The Karman line L K At a given altitude H D Dividing by this gives the correction factor F for a given type of rocket. C This is the step to determine the (F) Theoretical measurement distance D MT and / or the correction factor F CA step of recording this correction coefficient F C If applicable, the selected altitude H before the take-off of the rocket that defines the start of said space flight S Multiplied by this to get the reference distance D MR This is the step to obtain (G) activating a detection device in a watch on board the rocket prior to takeoff of the rocket.

[0034] The detection method further includes a detection stage including the following several detection steps: (H) Measurement Frequency F M The intrinsic acceleration vector of the watch in the three-dimensional coordinate frame of the watch is measured intermittently using the detection device, and the norm A of the measured intrinsic acceleration vector is calculated for each measurement result in the electronic unit. M (t n ), and norm A M (t n t) minus the norm of the acceleration of gravity, n is a time equal to n·P, where n is the number of measurements made since at least the liftoff of the rocket, incremented by one unit for each new measurement, and P is the period determined by the measurement frequency, step. (I) in the electronic unit, a step of numerically calculating a double integral over time of the norm of the characteristic acceleration vector of the watch from or at least since the take-off of the rocket, or of this norm minus the norm of the acceleration of gravity, the norm of the characteristic acceleration vector being calculated based on said norm A of the characteristic acceleration vectors measured at intervals; M (t n ) is determined based on time t m Comparison distance D for C (t m ), where m is a positive integer and each m corresponds to one of the numbers n. (J) Each comparison distance D C (t m) at the given altitude H D When using the theoretical measurement distance D MT and the selected altitude H S When using the reference distance D MR Compare with the comparison distance D C (t m ) are the theoretical measurement distances D MT or reference distance D MR recording in a memory of the portable article the detection by the detection device of a passage of the Kármán line by the portable article when the detected ΔT is greater than ΔT.

[0035] In one preferred alternative embodiment of this detection method, the acceleration sensor used to measure the intrinsic acceleration vector of the watch, and therefore typically the rocket, is a Micro-Electro-Mechanical System (MEMS) integrated in the watch.

[0036] Regarding step A), FIG. 4 shows the time from the takeoff of the rocket to the given altitude H D The nominal acceleration A for a particular rocket until it crosses the Karman line defined by N The curve for (t) is shown below. Note that the acceleration A N Providing (t) is a method of calculating the acceleration A at a plurality of successive times, particularly at discontinuous times, at least from takeoff until the passage of the given altitude. N As shown in the graph of FIG. 4, the method may include providing at least a plurality of predetermined values ​​of theoretical motion acceleration A N (t) may temporarily become negative, i.e. the rocket's speed may temporarily decrease, therefore the nominal kinetic acceleration is given with its mathematical sign and must be entered with this mathematical sign in the formula given in step D).

[0037] In one alternative embodiment, the acceleration A N (t) is the time from takeoff to at least a given altitude H DThe theoretical distance traveled by the rocket over time, at least at successive intervals, especially at intermittent intervals, until the passage of FT (t) and the acceleration A N (t) is the theoretical distance traveled by the rocket as a function of time, L FT (t) via the double derivative of this theoretical travel distance. N (t) is the theoretical altitude H of the rocket over at least a number of successive, and especially intermittent, periods of time. FT (t) and the theoretical trajectory of the rocket in space from the start to at least the passage of a given altitude z=T FT (x) (for simplicity, in the vertical plane XZ, z being the variable corresponding to the altitude, and x being the variable corresponding to the horizontal distance from the launch point of the rocket), and the nominal motion acceleration A N (t) is the mathematical and / or numerical calculation of the theoretical altitude H FT (t) and the theoretical trajectory T that this rocket will follow in space. FT (x) and, thanks to these two functions, the theoretical travel distance L FT (t) can be obtained.

[0038] With respect to step (B) of this detection method, FIG. 5 shows the theoretical inclination angle θ of the rocket of interest. T FIG. 5 shows an example of a curve of (t) as a function of time. FIG. 5 also shows the measured inclination angle θ over time during a space flight of a particular type of rocket. M This shows the curve for (t) at time T B It has been shown that a linear approximation from is relatively accurate here. B The rocket will move from time 0 to time T B The theoretical inclination angle θ T The vertical direction is traced so that (t) is 90°. Note that the theoretical tilt angle θ T(t) is the theoretical inclination angle θ at multiple successive times, particularly at intermittent times, from the launch of the rocket until at least the passage of a given altitude. T The method may involve providing at least a plurality of predetermined values ​​of (t).

[0039] Figure 2 shows the trajectory of rocket 22 at z=T F The example shown in the figure is in no way limiting the theoretical curves that can be considered, which are usually specific to each type of rocket (and in particular, for the Space Shuttle, the type of launch vehicle). The inclination angle θ(t) at time t between the direction of the rocket at time t and the horizontal plane is the angle of inclination θ(t) at the spatial position P S (t) Rocket trajectory z=T F The angle θ(t) is defined as the tangent of the angle θ(t) at the rocket's spatial position P S (t) trajectory T for horizontal distance x to F (x). This gives us the mathematical relationship tanθ(t)=dT F (x) / dx is obtained, where x=E H (t) and E H (t) is the horizontal distance of the rocket from the starting point as a function of time. Similarly, T FT (x) is the theoretical trajectory of a given type of rocket, and θ T (t) is the theoretical inclination angle of this rocket at time t, and the theoretical inclination angle θ T (t) is obtained by mathematical and / or numerical means from the mathematical relationship, tan θ T (t)=dT FT Through (x) / dx, the theoretical orbit z=T FT (x), where x=E HT (t) and E HT (t) is the theoretical horizontal distance of the rocket from the starting point as a function of time. Note that the function E HT(t) is the mathematical and / or numerical representation of the theoretical trajectory T of the rocket as a function of time. FT (x) and nominal motion acceleration A N (t), or theoretical altitude H FT (t). Thus, in one alternative embodiment, the theoretical tilt angle θ T (t) is the theoretical trajectory of the rocket in space, T FT (x) and the theoretical horizontal distance E of this rocket HT (t) is provided in step (B) of the detection method. This theoretical horizontal distance E HT (t) is the nominal motion acceleration A of the rocket as a function of time, in particular mathematically and / or numerically. N (t) and theoretical orbit z=T FT Based on (x), or instead of this theoretical orbit and theoretical altitude H FT The judgment can be made based on (t).

[0040] Theoretical flight time T K With regard to step (C) relating to, in a simplified alternative embodiment, it is possible to estimate this theoretical flight time based on at least one previous space flight with a rocket of the type of interest. In one advantageous alternative embodiment, which does not require a previous flight, the theoretical flight time T K is calculated by mathematical and numerical means as the nominal kinetic acceleration A of the rocket. N (t) and theoretical inclination angle θ T (t) is determined based on the theoretical travel distance of the rocket L T By defining (t) as a function of time, the following approach can be adopted: FT (t) and the theoretical travel distance of this rocket L T (t), i.e., the infinitesimal / singular variation in theoretical altitude, dH FT (t)=dL T (t) sinθ T (t), where dH FT(t) is the infinitesimal / single-dimensional variation of the theoretical travel distance. On the other hand, the variation dL T (t)=V N (t)dt, where V N (t) is the nominal speed of the rocket at time t, and dt is the infinitesimal / singular variation in time. If velocity is equal to the integral of acceleration with respect to time, then the nominal speed V N (t) is motion A N Based on the nominal acceleration of (t), it can be mathematically and / or numerically determined. Therefore, based on the above mathematical relationship, the theoretical altitude H FT Infinitesimal / basic variation of (t) dH FT We can define (t) as a function of given (nominal / theoretical) variables, which gives us dH FT (t)=V N (t) sinθ T (t)dt Where:

[0041] TIFF0007675888000002.tif10170

[0042] Theoretical altitude H FT (t) is the dH calculated by mathematical and / or numerical means FT (t) over time. The theoretical flight time T K To determine this, we use the formula, H FT (T)=H D is solved, where H D is a given altitude and T is a variable.

[0043] FIG. 6 shows the nominal motion acceleration A N The curve of (t) and the theoretical tilt angle θ shown in Fig. 5 T (t) curve and the theoretical height H as a function of time FT An example of the curve (t) is shown.

[0044] Steps D) and E) of this detection method have the following characteristics: These steps D) and E) determine a theoretical measurement distance D corresponding to a predetermined reference value. MT This theoretical measurement distance D is designed to enable accurate determination of MT and a comparison distance, which in the main embodiment of the invention is subsequently calculated precisely in the electronic unit of the watch, can be compared on the basis of measurements of the specific accelerations given by an acceleration sensor arranged in the watch during the space flight of the rocket carrying the watch. In this main embodiment of the watch, it is conceivable that the autonomous detection device uses as its measurement means only an acceleration sensor arranged to be able to measure the vector of the specific accelerations experienced by the watch. This method involves the determination in advance, i.e. in a preliminary step before the space flight of interest, of a fictitious theoretical distance, the theoretical measurement distance D MT It is a fictitious theoretical distance, since it does not correspond to the distance theoretically travelled by the rocket between the ground and the Kármán line, but to the theoretical distance resulting from the fact that the intrinsic acceleration of the watch is being measured. Also, taking into account the limited measuring means, a reference value is given that depends only on the norm of the intrinsic acceleration, a vector in the coordinate frame of the watch 2 given by the acceleration sensor, which is advantageously corrected by the norm of the gravitational acceleration, by subtracting it from the norm of the intrinsic acceleration and from the rocket's trajectory. The passage of the Kármán line is therefore determined on the basis of the norm of the intrinsic acceleration of the watch, and therefore usually of the rocket on which it is mounted, which norm is, as mentioned above, independent of the spatial orientation of the coordinate frame of the acceleration sensor.

[0045] This detection method takes into account that the norm of the intrinsic acceleration vector for a given acceleration of motion varies with the inclination of the rocket. In fact, this norm is subtracted from the norm of the acceleration of gravity, which does not accelerate the motion of the watch / rocket if the rocket is not oriented vertically. Figures 2 and 3 show the acceleration of motion a for the rocket.* , the measured specific acceleration a M * , and the gravitational acceleration a E * The vector relationship between the acceleration vector a(t) and the * , and the measured characteristic acceleration vector a M (t) * is the spatial position P of the rocket at time t of the space flight. S (t) corresponds to the gravitational acceleration vector a E * is always vertical and independent of the rocket's spatial position. The small centripetal acceleration experienced by the rocket as it gradually tilts is not taken into account in the relationship between the rocket's intrinsic acceleration, including such centripetal acceleration, and the rocket's kinetic acceleration, because this centripetal acceleration is small and insignificant for a rocket between the ground and the Kármán line. In this detection method, in a preliminary step before the space flight, specifically in step D, the nominal kinetic acceleration A given in steps A) and B) is calculated. N The theoretical specific acceleration A of the rocket over time t as a function of (t) PT (t) and the theoretical inclination angle θ of the rocket T Then, in step E), time 0 (t=0) corresponding to the takeoff of the rocket and time T corresponding to the theoretical flight time calculated in step C) are calculated. K Theoretical specific acceleration A between PT (t), or, advantageously, from this theoretical specific acceleration, the gravitational acceleration A E By double integral with respect to the norm of MT is calculated.

[0046] It should be noted that, in the absence of information indicating that an acceleration vector is being referred to, the description herein refers to the value of the referred acceleration (which is the length of a mathematically signed vector given as a function of the direction of motion, and which in the description herein relates only to the acceleration of motion) or to the norm of the acceleration vector (i.e., the absolute value of the length of the vector, as in the case of the intrinsic acceleration of a rocket and the acceleration of gravity). More specifically, when an acceleration is referred to, acceleration means the value of that acceleration, and when a norm of an acceleration is referred to, acceleration means the norm of the corresponding acceleration vector, i.e., the absolute value of the acceleration.

[0047] Theoretical measurement distance D MT The Karman line L K At a given altitude H D This division gives the correction factor F for a given type of rocket in the context of the detection method according to the invention. C Determine.

[0048] In step F), before the space flight, i.e. before the rocket takes off, the theoretical measurement distance D MT and / or correction factor F C is stored in the memory of the watch. C is the altitude of the Kármán line measured by the user on a wristwatch. S If it is expected that it will be possible to select the reference distance D MR In this case, it is useful to obtain the correction factor F C , the altitude H selected for the Kármán line S Multiplying by this, the reference distance D MR Calculate the reference distance D MR Here, at a given altitude H D Theoretical measurement distance D is accurately determined for MT Considering the linear approximation made based on

[0049] Steps H) to J) of this detection method concern the detection of the passage of the Kármán line during a space flight of a given type of rocket, using a wristwatch according to the invention, in particular a wristwatch according to the main embodiment. The detection device 6 of the wristwatch 2 thus measures the components of the intrinsic acceleration vector of the wristwatch along the three orthogonal axes of the three-dimensional coordinate frame defined by the acceleration sensor, at the measurement frequency F M and for each measurement, the electronic unit calculates the theoretical measurement distance D MT In the calculation of theoretical specific acceleration A PT At each measurement time t depending on whether (t) is reduced by the norm of gravitational acceleration n The norm A of this characteristic acceleration vector measured at M (t n ), or norm A M (t n ) to the gravitational acceleration A E In order to be able to perform the measurements of the acceleration vector of the watch intermittently, the watch comprises a time base arranged to enable the sequential determination of a period corresponding to a planned measurement frequency and thus to enable the detection device to control the acceleration sensor to perform the planned intermittent measurements.

[0050] Then, according to the theoretical calculations made in the previous preliminary step, the electronic unit 12 calculates the specific acceleration A of the watch on board the rocket from the take-off of the rocket. P Numerically calculate the double integral over time of the norm of (t), or advantageously this norm minus the acceleration of gravity. P The norm of (t) is generally the above norm A of the characteristic acceleration vector measured intermittently. M (t n ) is determined based on time t m Comparison distance D for C (t m), where m is a positive integer and each m corresponds to one of the numbers n. In one preferred alternative embodiment, the time t n For each measurement taken at a comparison distance D C (t n ) is calculated. Finally, each comparison distance D C (t m ) is calculated, preferably in near real time, for a given altitude H D When using the theoretical measurement distance D MT and the selected altitude H S When using the reference distance D MR It is compared with the comparison distance D C (t m ) is the theoretical measurement distance D MT and reference distance D MR It is an imaginary distance such as the time t m Comparison distance D in C (t m ) are the theoretical measurement distances D MT or reference distance D MR If the distance is greater than 100 m, the electronic unit of the detection device records in the watch's memory that the watch, and therefore the rocket, is on the Kármán line L K The rocket's takeoff is intermittent and begins before takeoff, and the measured normal acceleration norm A M (t n ) can be easily detected. In fact, as long as this norm is substantially equal to the norm of the acceleration of gravity, the electronic unit can conclude that the rocket has not yet taken off and can determine, for example, that the time of the rocket's take-off is when the norm of the measured specific acceleration exceeds a certain given limit value. P From the norm of (t) to the gravitational acceleration A EIn the main advantageous alternative embodiment using the value minus the norm of , it is advantageously possible to start calculating the integral of this specific acceleration corrected by gravity before the take-off of the rocket, taking into account that this value has no theoretical value and is practically zero in practice. The value of the integral therefore remains substantially zero before the take-off of the rocket. Note that the measurements of the specific acceleration made by the acceleration sensor are advantageously filtered to remove any parasitic noise.

[0051] In a particular implementation, in this detection method, step I) of calculating the double integral over time in the electronic unit involves: after each measurement of the intrinsic acceleration, calculating the time t n-1 and n A is the constant value of the norm of the specific acceleration for each period P between C (t n ), which involves performing double integration by increments, and the value of this constant is the norm A M (t n ) and / or norm A M (t n-1 ) for each period P, calculate the increase in velocity corresponding to the constant value or the constant value minus the norm of the acceleration of gravity, and n Estimated speed V at E (t n ) and determine the constant value A C (t n ) or this constant minus the gravitational acceleration and time t n-1 Estimated speed V at E (t n-1 ), based on the basic distance d n and determine the basic distances d1 to d2 obtained at the end of the previous measurement of the specific acceleration. n-1 The sum of the basic distance d n Adding, time t n Comparison distance D in C (t n ) It should be noted that the calculations performed in the electronic unit advantageously require relatively low computing power.

[0052] The user specifies the Kalman limit L K The corresponding altitude H S In an alternative embodiment, where the user can select the altitude H, this selection is indirect, i.e., via a control member carried by the watch, the user is allowed to select the inclination angle of the rocket corresponding to the passage of the Kármán line by this rocket. The selection of the inclination angle involves inputting an arbitrary value based on the data of the space flight of interest, or selecting a particular value from a number of suggested values ​​in a list that the watch can sequentially display. This selection is carried out based on the altitude H selected. S is given directly before the space flight of interest on a given type of rocket. S is determined as a function of the selected tilt angle, and the electronic unit 12 converts a given tilt angle to a corresponding selected altitude H S It is configured so that it can be converted to

[0053] According to an improved implementation, the detection method according to the invention includes a number of distinct given altitudes H that can be selected by the user of the watch. D j For each given altitude (j=1 to J), the theoretical measurement distance D MT Determine each theoretical measurement distance D MT j and / or the corresponding correction factor F C j is stored in the memory 4 of the portable watch, and the theoretical measurement distance D MT j or the correction factor F C j One of the following is the direct or Kármán limit altitude H S Note that this improved implementation can be implemented by selecting the Kalman line L K Selectable altitude H SIt is advantageous if the range of the theoretical measurement distance D is an extended range, for example between 80km and 110km. In this case, the plurality of predetermined altitudes includes for example a value 85km in a first part of the range of selectable altitudes between 80km and 90km, a value 95km in a second part of the range of selectable altitudes between 90km and 100km, and a value 105km in a final third part of the range of selectable altitudes between 100km and 110km. MT j and / or the corresponding correction factor F C j are predetermined and entered into the memory 4 of the watch. Each correction factor is therefore used to provide a particular reference distance which corresponds to only a part of the range of selectable altitudes, via a linear approximation based on a theoretical measured distance for a given altitude which is substantially in the middle of the relevant part of said range.

[0054] Below, a main embodiment of a watch according to the invention, which makes it possible to implement the detection method according to the invention, will be described.

[0055] In the watch 2 according to this embodiment, the detection device 6 measures the components of the intrinsic acceleration vector of the watch along the three orthogonal axes of a three-dimensional coordinate frame 10 defined by the acceleration sensor 8 and linked to the watch, at a measurement frequency F M The present invention is configured to be capable of measuring intermittently, i.e., by utilizing the detection device to measure an intrinsic acceleration vector in the coordinate frame of the watch, which is equal to the vector sum of the forces acting on the watch, excluding gravity, divided by the mass. Note that such an intrinsic acceleration vector can be provided by an acceleration sensor formed by a microelectromechanical system (MEMS), which is provided in a preferred alternative embodiment. The detection device 6 then calculates, in the electronic unit 12, the norm A of the intrinsic acceleration vector measured by the acceleration sensor 8 for each measurement. M (t n ) or norm A M (t n ) to the gravitational acceleration A Eminus the norm of t n is equal to n P, where n is the number of measurements made at least since launch, incremented by one for each successive measurement, and P is the period determined by the measurement frequency.

[0056] The electronic unit 12 also determines the specific acceleration A of the wristwatch, and therefore of the rocket. P (t), i.e., the norm A of the characteristic acceleration vector P The system is configured to be able to numerically calculate the double integral over time, at least from the take-off of the rocket, of (t), or this specific acceleration / norm minus the norm of the acceleration of gravity (assuming that the watch experiences little or no acceleration from the user, other than that induced by the rocket on the watch). P (t) is the norm A of the characteristic acceleration vector measured intermittently M (t n ) based on time t m Comparison distance D in C (t m ), where m is a positive integer and each m corresponds to the number n above. Then, the detection device 6 obtains each comparison distance D C (t m ) with a predetermined reference value stored in the memory, or a correction factor F C Altitude H selected via S , and the calculated reference value obtained for C (t m ) is greater than or equal to said predetermined reference value, these values ​​and said correction coefficients being those defined above in relation to the general embodiment of the watch.

[0057] In one advantageous alternative embodiment, said calculation of the double integral over time, which is carried out in the electronic unit 12, is carried out after each measurement of the specific acceleration at a time t n-1 andn A norm A corresponds to the norm of the characteristic acceleration vector for each period P between M (t n ) and / or norm A M (t n-1 ), a constant value A C (t n ), by performing double integration by increments to calculate the increase in velocity corresponding to the constant value or the constant value minus the norm of the acceleration of gravity for each period P, thereby obtaining the constant value A C (t n ), or the norm of gravitational acceleration and time t n-1 Estimated speed V at E (t n-1 ) minus, based on time t n Estimated speed V at E (t n ) and the basic distance d n and the basic distances d1 to d2 obtained at the end of the previous measurement of the specific acceleration are determined. n-1 The sum of the basic distance d n Adding, time t n Comparison distance D in C (t n ) is obtained.

[0058] In a particular alternative embodiment, the watch comprises visual and / or vibrational means (vibrator) and / or, optionally, sound generating means, adapted to be able to indicate the passage of the Kármán line by the watch as soon as the detection device detects the passage of the Kármán line by the watch. n Immediately after each measurement of the vector of the specific acceleration of the watch at C (t n ), the passage of the Kármán line by the watch, and therefore the rocket, can be detected in near real time.

[0059] In one alternative general embodiment, the watch is adapted to record at least the first passing of the Kármán line by the watch, and preferably each passing of the Kármán line by the watch, and is provided with display means 30 adapted to indicate, automatically and / or on command, whether a passing of the Kármán line by the watch has occurred, and preferably to indicate the number of times this event has occurred.

[0060] In one preferred alternative embodiment, the watch is arranged so that the detection of the passage of the Kármán line by the watch can be permanently recorded in the memory 4, this recording being made in a protected part 4a of the memory such that the user of the watch cannot program this protected part 4a.

[0061] 7A-7D show various messages given by the watch 2 via the digital display 30 during the space flight. By pressing the push button 16 for a long time, the user on board the rocket activates the mode of the watch for detecting the passage of the Kármán line. The watch then displays "KARMAN DET READY" (Fig. 7A), i.e. indicating that the detection device 6 is ready to detect the passage of the Kármán line by the watch 2 or the rocket. The detection device can then determine when the rocket is taking off based on the measurement of the specific acceleration of the watch. At this point, the digital display displays "KARMAN ON TK OFF" (Fig. 7B), i.e. indicating that the detection device is active and the rocket is taking off. The digital display then displays the elapsed time since take-off at a given time. For example, 125 seconds is represented by displaying "FLIGHT TM 125" (Figure 7C). Finally, as soon as the watch detects the passage of the Kármán line and thus the entry into space, the watch displays the message "U ARE IN SPACE" (Figure 7D) (where "U" stands for "YOU"), i.e. indicating that the astronaut has reached space with the rocket.

[0062] Figures 8A and 8B show examples of messages that the watch can display, in particular when it is not in the middle of at least one space mission in which it has participated as an instrument for detecting the passage of a Kármán line by a space astronaut. By simultaneously pressing the two push-buttons 16 and 17, the watch displays the message "WORN IN SPACE" (Figure 8A), i.e. that the watch has been worn in space and has passed a Kármán line, based on the data stored in its memory, preferably in a protected portion 4a formed by a non-volatile memory that can be written only once ("OTP" memory). Preferably, by subsequently pressing the push-button 17, the watch displays the number of times it has entered space, by the message "KARMAN DET NB" and said number (i.e. "2" in the example shown in Figure 8B).

[0063] It has already been mentioned that the watch can be configured to allow the input of various selectable parameters and / or variables, in particular the altitude of the Kármán limit at the time of this event, or the intended inclination angle of the rocket. This data can in particular be input via a touch screen formed in the crystal of the watch and / or by increasing the number of scrolls of a portion of the digital display 30, and via push buttons that allow the scrolling to stop at a predicted value or to start scrolling. Alternatively, the hands of the analog display 34 can be used for this purpose.

[0064] In addition, the theoretical measurement distance D MT , and the corresponding correction factor F that allows the calculated reference value to be determined. C is related to a given type of rocket (also called "launch vehicle type") as described above. In one improved embodiment, for some rocket types, the theoretical measured distance D MTand / or the corresponding correction coefficients can be entered into the memory 4 of the watch. In this case, the watch comprises means for selecting, prior to a space flight, the type of rocket of interest for the planned detection of the passage of the Kármán line. This selection means can in particular use a list containing the different types of rockets envisaged for the detection application of the watch, which list can be viewed by using a control member of the watch to scroll through the different types of rockets envisaged and selecting them using another control member.

[0065] Finally, each theoretical measurement distance D MT and the corresponding correction coefficients F C is the given altitude H D This given altitude can be an altitude measured from sea level, i.e., independent of the rocket launch site, or an altitude measured from a particular launch site.

[0066] In one sophisticated alternative embodiment, the launch site can also be selected by the user prior to the space flight via the control member and display means of the watch. Each launch site thus corresponds to one or more theoretical measured distances and one or more corresponding correction factors. In this case, the altitude H selected by the user is S is the height above sea level. For simplicity while still being accurate, the given altitude H is used to determine one or more reference values ​​in advance. D and the user-selected altitude H S In both cases where θ is used, it proves advantageous to use the altitude measured from an arbitrary launch site, i.e. the height measured above the ground at the launch point of the rocket. [Explanation of symbols]

[0067] 2 Portable items 4. Memory 4a Protected Parts 6 Detection Devices 8. Accelerometer 10 Three-dimensional coordinate frame 12 Electronic Unit 16, 17 Push button 18 Stem crown 22. Rocket 30 Display Means 34 Analog Display

Claims

1. A given altitude H for a given type of rocket D or the selected altitude H S The Karman line L defined by K A method for detecting the passage of a rocket using a portable object worn by a user and carried on board the rocket during a space flight of the rocket, comprising the steps of: the portable article comprises a memory, a time base, and a detection device; the detection device is formed by an acceleration sensor capable of measuring a characteristic acceleration vector of the portable object in a three-dimensional coordinate frame of the portable object, and an electronic unit adapted to process the measurement results provided by the acceleration sensor, The intrinsic acceleration vector of a portable object is equal to the vector sum of the forces acting on the portable object, excluding gravity, divided by the mass of the portable object, the time base is used to sequentially determine a period for making measurements of the intrinsic acceleration vector; The method includes a preliminary step for a portable object aboard a rocket for a space flight, the preliminary step comprising: At least the given altitude H from the takeoff of the rocket, which is defined as time 0. D the nominal motion acceleration A of said given type of rocket, which is a scalar value in units equal to the gravity of the Earth, as a function of time t, until the passage of N providing (t); The given altitude H from the takeoff of the rocket D The theoretical inclination angle θ of the given type of rocket relative to the horizontal plane as a function of time t until at least one pass of T providing (t); The given altitude H from the takeoff of the rocket D The theoretical flight time T of the given type of rocket until the passage of K determining or providing Based on the nominal motion acceleration and the theoretical inclination angle, a theoretical specific acceleration A for the given type of rocket as a function of time is defined in units of the gravitational force of the Earth by the following formula: PT determining (t); By numerical and / or mathematical means, the time 0 (t=0) corresponding to the take-off of the rocket and the time T corresponding to the theoretical flight time are calculated. K The theoretical specific acceleration A PT (t), or the double integral of the theoretical specific acceleration minus the norm of the gravitational acceleration, and the Kármán line L K The given altitude H D The value divided by is the correction factor F for the given type of rocket. C Define the theoretical measurement distance D MT and calculating The theoretical measurement distance D MT and / or the correction coefficient F C in the memory of the portable article, where, if applicable, in the electronic unit, before the take-off of the rocket, which defines the start of the space flight, the correction factor F C and the selected altitude H S is multiplied to obtain the reference distance D MR , and and activating said detection device of a portable article on board the rocket prior to take-off of the rocket; The detection method includes a detection step, the detection step comprising: Measurement frequency F M The detection device is used to measure the characteristic acceleration vector of the portable article intermittently, and in the electronic unit, a norm A of the measured characteristic acceleration vector is calculated for each measurement. M (t n ), or the norm A M (t n ) minus the norm of the gravitational acceleration, n is a time equal to n·P, where n is at least the number of measurements made since the liftoff of the rocket, incremented by one unit for each new measurement, and P is a period determined by said measurement frequency; In the electronic unit, a double integral is calculated numerically over time of the norm of the intrinsic acceleration vector of the portable object, or this norm minus the norm of the acceleration of gravity, at least from the take-off of the rocket, where the norm of the intrinsic acceleration vector is calculated based on the norm A of the intrinsic acceleration vectors measured at intervals. M (t n ) is determined based on time t m Comparison distance D C (t m ), where m is a positive integer and each m corresponds to one of said numbers n; Each comparison distance D C (t m ) at the given altitude H D When using the theoretical measurement distance D MT and the selected altitude H S When using the reference distance D MR and the comparison distance D C (t m ) is the theoretical measurement distance D MT or reference distance D MR and recording, by said detection device, in a memory of the portable article, the detection of the passage of the Kármán line by the portable article when the detected distance is greater than A detection method comprising:

2. The step of calculating in the electronic unit the double integral over time of the norm of the intrinsic acceleration vector of the portable article, or of this norm minus the norm of the acceleration of gravity, comprises the steps of: calculating, after each measurement of the intrinsic acceleration vector, the double integral over time of the intrinsic acceleration vector of the portable article at a time t n－1 and n A constant value A of the norm of the characteristic acceleration vector for each period P between C (t n ), which involves performing double integration by increments, This constant value is the norm A M (t n ) and / or norm A M (t n－1 ), whereby, for each period P, the increase in velocity corresponding to the constant value or the constant value minus the norm of the acceleration of gravity is calculated, and the constant value or the constant value minus the norm of the acceleration of gravity and the time t n－1 Estimated speed V E (t n－1 ) based on time t n Estimated speed V E (t n ) and the basic distance d n Decide, And the basic distance d obtained at the end of the previous measurement of the intrinsic acceleration vector 1 ~d n－1 The sum of the basic distance d n In addition, time t n Comparison distance D C (t n ) 2. The detection method according to claim 1 .

3. The theoretical flight time T K is determined in the preliminary step based on the nominal motion acceleration and the theoretical tilt angle by mathematically and / or numerically solving the following equation: Here, H D is the given altitude, time T is a variable, is 2. The detection method according to claim 1 .

4. The selected altitude H S is determined as a function of the rocket inclination angle selected for the passage of the Kármán line by this rocket, The tilt angle is imparted to the portable article prior to a space flight with the rocket.

2. The detection method according to claim 1 .

5. The theoretical measurement range is determined based on a selectable number of discrete given altitudes H D j For each given altitude (j=1 to J), Each theoretical measurement distance D MT j and / or the corresponding correction coefficients F C j is stored in the memory of the portable item and the theoretical measurement distance D MT j or a correction factor F C j It is possible to select one of the following two methods, either directly or by selecting the altitude of the Kármán limit:

2. The detection method according to claim 1 .

6. The acceleration sensor is formed by a microelectromechanical system (MEMS). The detection method according to any one of claims 1 to 5.

7. A portable item (2) that can be worn by a user, comprising a memory (4), a time base and a detection device (6), said detection device (6) being formed by an acceleration sensor (8) capable of measuring the acceleration vector of a portable object in a three-dimensional coordinate frame (10) linked to said portable object, and by an electronic unit (12) capable of processing the measurement results provided by said acceleration sensor, the time base is used to sequentially determine a period for making measurements of the acceleration vector; The detection device (6) detects, during a space flight of a given type of rocket, the Karman line L due to portable objects on board this rocket. K The device is configured to be capable of autonomously detecting the passage of The Karman line L K is the given altitude H D , or a selected altitude H, which can be selected by the user directly or by selecting another spatial variable. S , as defined by The crossing of the Karman line by a portable object is from the takeoff of the rocket to the crossing of the Karman line L K and measuring the acceleration vector of the portable object by the acceleration sensor until the object passes through a predetermined reference value stored in the memory (4) before the takeoff or a correction factor F that is previously determined and stored in the memory before the takeoff. C and the altitude H selected by the user for the Karman line prior to takeoff. S and based on a reference value calculated in the electronic unit based on The predetermined reference value and the correction coefficient F C is the given altitude H D is relative to The electronic unit is configured to calculate a change in a comparison distance over time based on the intermittent measurements of the acceleration vector of the portable object, and to compare this comparison distance over time with the predetermined reference value or the calculated reference value to detect a passage of a Kármán line by the portable object. A portable item (2).

8. the detection device (6) is configured such that the comparison distance is calculated based on a norm of an acceleration vector in the three-dimensional coordinate frame (10) measured by the acceleration sensor (8); The electronic unit (12) is adapted to be able to calculate the norm. Portable item (2) according to claim 7.

9. The correction coefficient F C is the predetermined reference value at the given altitude H D is equal to the value divided by 8. The portable item according to claim 7.

10. The predetermined reference value is the distance from the takeoff of the rocket to the Karman line L K The given altitude H D Based on at least one theoretical function of space variables related to the rocket, 8. The portable item according to claim 7.

11. The memory (4) stores a number of given altitudes H D j (j=1 to J), each of the predetermined reference values ​​is determined based on at least one theoretical function of a spatial variable relative to the rocket from liftoff to a corresponding given altitude of the rocket; Each of the given altitudes is user selectable to allow comparison over time of the comparison distances calculated when a passage of a Kármán line by a portable item is detected. Portable item (2) according to claim 7.

12. The memory (4) stores a number of given altitudes H D j (j=1 to J), Each correction factor is adjusted by the user to allow a comparison over time of the comparison distance calculated when a crossing of the Kármán line by a portable item is detected with a reference value that depends on the selected correction factor and the selected altitude. K can be selected as a function of the altitude selected for Portable item (2) according to claim 7.

13. The plurality of given altitudes H D j A plurality of predetermined reference values ​​are respectively set for each of the predetermined reference values ​​is determined based on at least one theoretical function of a space variable associated with the rocket from liftoff of the rocket to a corresponding given altitude; Each of the correction factors is equal to each of the predetermined reference values ​​divided by each of the given altitudes.

13. The portable item according to claim 12.

14. The acceleration sensor (8) is formed by a microelectromechanical system (MEMS). Portable item (2) according to any one of claims 7 to 9 and 11.

15. The acceleration sensor (8) is formed by a microelectromechanical system (MEMS), The predetermined reference value further includes the nominal motion acceleration A of the rocket. N (t) is determined based on Portable item (2) according to claim 10.

16. The acceleration sensor is formed by a microelectromechanical system (MEMS), Each predetermined reference value further includes the nominal motion acceleration A of the rocket. N (t) is determined based on 14. The portable item according to claim 12 or 13.

17. The detection device (6) uses the acceleration sensor (8) to calculate the intrinsic acceleration vector of the portable item (2) in the three-dimensional coordinate frame (10) at a measurement frequency F M The device is configured to be capable of performing intermittent measurements. This characteristic acceleration vector is equal to the vector sum of the forces acting on the portable object, excluding gravity, divided by the mass of the portable object, The detection device (6) calculates in the electronic unit (12) for each measurement the norm A of this measured characteristic acceleration vector. M (t n ), or this norm A M (t n ) minus the norm of the gravitational acceleration, t n is equal to n P, where n is the number of measurements made since at least launch of the rocket, incremented by one unit for each successive measurement, and P is the period defined by said measurement frequency; said electronic unit (12) being adapted to numerically calculate a double integral over time, at least from the lift-off of the rocket, of the norm of the intrinsic acceleration vector of the portable object, or of this norm minus the norm of the acceleration of gravity; The norm of the characteristic acceleration vector is the norm A of the characteristic acceleration vectors measured intermittently. M (t n ) is determined based on time t m Comparison distance D C (t m ), where m is a positive integer and each m corresponds to one of said numbers n; The detection device (6) detects each comparison distance D C (t m ) at the altitude H selected via the predetermined reference value stored in memory or the correction factor. S and thus the comparison distance D C (t m ) is greater than the predetermined reference value or the reference value. Portable item (2) according to claim 14.

18. The calculation of the double integral over time, which is carried out in the electronic unit, is carried out after each measurement of the characteristic acceleration vector at a time t n－1 and n A constant value A of the norm of the characteristic acceleration vector for each period P between C (t n ), which involves performing double integration by increments, This constant value is the norm A M (t n ) and / or norm A M (t n－1 ), whereby for each period P, an increase in velocity up to or equal to said constant value or said constant value minus the norm of the acceleration of gravity is calculated, The constant value A C (t n ), or the constant value minus the norm of the gravitational acceleration, and time t n－1 Estimated speed V E (t n－1 ), based on time t n Estimated speed V E (t n ) and the basic distance d n Decide, And the basic distance d obtained at the end of the previous measurement of the intrinsic acceleration vector 1 ~d n－1 The sum of the basic distance d n Adding, time t n Comparison distance D C (t n ) 18. The portable item according to claim 17.

19. comprising visual and / or vibration and / or sound generating means adapted to indicate the passage of the Kármán line by the portable item as soon as the detection device detects the passage of the Kármán line by the portable item. The portable article according to any one of claims 7 to 13.

20. the portable item (2) is configured to record at least a first passage of the Kármán line by the portable item; The portable article (2) is provided with a display means adapted to indicate, automatically and / or on command, whether or not a passage of the Kármán line has been made by the portable article. Portable item (2) according to any one of claims 7 to 13.

21. The detection of the passage of the portable object through the Kármán line can be permanently recorded in a memory; This recording is made in a protected portion of the memory (4a) to prevent the user of the portable article from programming said protected portion. Portable item (2) according to claim 20.

22. The portable item is a wristwatch. Portable item (2) according to any one of claims 7 to 13.

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