Method for verifying detection of the passage of a Kármán line by a user-carryable object, in particular a wristwatch

Abstract

To provide a validation method for detection of passage of a Karman line by a portable article.SOLUTION: The verification method relates to verification on detection of passage of a Karman line by a portable article (2) embarked in a rocket, and the portable article comprises: an acceleration sensor (8) capable of measuring acceleration of the portable article; and an electronic unit for processing the acceleration measurements made so as to detect passage of the Karman line by the portable article. The validation method comprises: calculating at least one confidence index related to the measurements made by the portable article for at least one variable being a function of force applied to the portable article; verifying whether at least one condition given to the at least one confidence index is met, so as to validate or not a detection of the passage of the Karman line by the portable article and therefore by the rocket. The present invention further relates to the portable article, in particular a watch, designed to be able to implement a detecting method and a validation method of passage of the Karman line according to the present invention.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an object, in particular a portable watch, for space applications, that can be carried by a user, said user being an astronaut or other individual traveling in space using a rocket or a space shuttle (hereinafter generally referred to as "rocket"). More specifically, the present invention relates to a method for verifying the detection of the passage of a Kármán line by such a portable object, said portable object being equipped for this purpose with an autonomous detection device and said method being implemented by said portable object.

[0002] The Kármán line defines the boundary between the traditional Earth atmosphere and space. It is typically taken to correspond to an altitude of 100 km. However, this altitude varies for different organizations, especially within the range of 85 km to 110 km. The Kármán line is also the boundary above which a spacecraft must fly at an orbital speed that allows it to maintain an orbit around the Earth in order to maintain flight. [Background technology]

[0003] 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]

[0004] The invention aims to provide a method for verifying the detection of the passage of a Kármán line by a portable object, in particular a portable watch, that can be carried by a user, both detection and verification being performed by the portable object on the basis of measurements performed by the portable object during a detection phase of the detection method implemented by the portable object. Such detection is therefore intended to be performed autonomously by the portable object during said detection phase of the detection method implemented by the portable object, and thus without the use of real-time communication either between the portable object and the rocket or between an external system, in particular one or more satellites providing position information in space. The invention further relates to such a portable object that can be carried by a user. [Means for solving the problem]

[0005] In particular, the portable article is intended to comprise a detection device formed by an acceleration sensor, a time base and an electronic unit, the detection device being adapted to measure the acceleration experienced by the portable article during a detection phase of a detection process / method implemented by the portable article and to be able to process the acceleration measurements made in the electronic unit, thereby enabling the detection of the passage of a Kármán line by the portable article on the basis of a predefined reference value, or a reference value calculated as a function of a predefined correction factor, and on the basis of an altitude selected by the user for the Kármán line within a given range of values, in particular within the range of 85-110 km. By "predefined" it should be understood to mean that the data of interest are recorded on the portable article before the detection phase of the detection process / method.

[0006] A portable object such as a watch cannot incorporate a sophisticated inertial navigation system, comprising an acceleration sensor designed to precisely measure the acceleration along the three axes of the coordinate frame of the portable object, and an angular velocity sensor (gyrometer) designed to precisely measure the angular velocity along said three axes, allowing to precisely determine the position of the portable object in a fixed coordinate frame. Furthermore, the cost of a precise inertial navigation system is very high. Therefore, in a preferred embodiment, the portable object according to the invention is characterized in that it is designed to be able to autonomously detect the passage of a Karman line by a portable object on board a given type of rocket, with the only technical means required being an acceleration sensor capable of measuring the components of the acceleration vector relative to the portable object in a coordinate frame linked to the portable object, a memory containing said predetermined or calculated reference values, and an electronic unit arranged to process the measurement results given by said acceleration sensor. Thus, the portable article does not require a gyrometer to detect the passage of the Kármán line, which can of course be small and formed by a microelectromechanical system (also called "MEMS"), but which is typically not very accurate and in any case not accurate enough to allow accurate detection of the change in the orientation of the coordinate frame specific to said acceleration sensor during the space flight 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 to determine its altitude over time. This preferred embodiment therefore avoids the problems associated with small gyrometers, which are relatively inaccurate in measurements requiring the detection of the passage of the Kármán line and therefore cannot give sufficiently accurate measurements of the angular velocity of the portable article to accurately determine its temporal orientation and its changes in position in space, in particular its altitude. On the other hand, relatively inexpensive 3D acceleration sensors of small dimensional configurations of the same order of magnitude can give accurate acceleration measurements along three axes.

[0007] In a preferred alternative embodiment, the method for detecting the passage of the Kármán line is arranged to calculate a comparison distance based on the norms of the acceleration vectors measured by the acceleration sensor, said electronic unit being arranged to calculate these norms and to perform a double integration over time of the norm of the acceleration vectors measured intermittently, or advantageously this norm minus the acceleration of gravity in the case of MEMS type accelerometers, to obtain a virtual comparison distance which is compared to said predetermined or calculated reference value. Although the acceleration sensor provides an acceleration vector in a native coordinate frame, 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, so that the uncertainty of the orientation of the coordinate frame of measurement for the acceleration measurements is not an issue. This preferred alternative embodiment is highly advantageous in order to overcome 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 Earth's coordinate frame that is variable during the space flight between the launch site and the Kármán line of the rocket, in particular because the rocket does not follow a vertical linear trajectory, and the orientation of the portable article may change over time relative to the rocket as a result of the movements of the user wearing the portable article, in particular in the case of a wristwatch.

[0008] During the development of a portable object and a method for detecting the passage of a Kármán line by a portable object, using as the only measurement in the detection phase of the detection method discontinuous measurements of the acceleration vector of the portable object and based on the calculation of the norm of the measured acceleration vector, the inventors realized that such a method may, in certain concrete circumstances, give erroneous results, in particular detecting a passage of a Kármán line when it has not occurred. This is called a "false positive". This is problematic for portable objects, in particular for portable watches whose purpose is to indicate exceptional events to the user, for example an entry into space. It is therefore desirable to find a way to determine the likelihood that the portable object will autonomously detect the passage of a Kármán line in the detection phase, and to be able to activate or deactivate such detection.

[0009] Among the situations where the considered detection method, and in particular this preferred alternative embodiment, may give rise to erroneous results are those where the portable object experiences a series of sudden accelerations, for example a series of impacts in short intervals. This may occur in several voluntary or involuntary situations, or when playing sports such as tennis or table tennis while wearing the portable watch designed for the space application of interest on the wrist. Other activities, such as running, may also give rise to erroneous detections, even if the portable watch worn on the user's wrist does not experience strong impacts. Also, acrobatic maneuvers in aircraft are prone to "false positive results", as are rides on certain attractions in amusement parks where the wearer experiences relatively large accelerations, as in the case of "roller coasters". Certain other situations may also lead to erroneous detection of the passage of the Karman line in the context of the present invention, for example when the portable watch is placed inside a device (e.g. a clothes dryer or a salad spinner) that exerts a large central force on the object placed inside it. The present invention therefore aims to provide a means for detecting at least a certain number of cases where the detection of a Kármán line passage is uncertain, unlikely or unlikely to occur, and for overriding such false detections.

[0010] In order to achieve the above object, the present invention relates to a method for verifying the detection of a passage of a Kármán line, defined by a given altitude, by a portable object portable by a user, said portable object comprising a detection device formed by an acceleration sensor, a time base and an electronic unit, said detection device being adapted to measure the accelerations experienced by said portable object during a detection phase of the method for detecting the passage of a Kármán line implemented by said portable object and to process said acceleration measurements in said electronic unit, thereby enabling the detection of the passage of a Kármán line by said portable object based on said acceleration measurements and on data recorded on said portable object before said detection phase of said detection method. The verification method utilizes sequential measurements made by said portable object during said detection phase of said detection method for at least one variable dependent on at least one force applied to said portable object. The verification method is executed by an electronic unit which calculates at least one confidence index associated with the sequential measurements and checks whether at least one condition for the at least one confidence index is fulfilled in order to validate or invalidate the detection of the passage of the Kármán line by the portable article.

[0011] In one advantageous alternative embodiment, the acceleration centre measures an intrinsic acceleration vector of the portable object in the coordinate frame of the portable watch, the acceleration value being the norm of the intrinsic acceleration vector minus the norm of the acceleration of gravity, the intrinsic acceleration vector of the portable object being equal to the vector sum of the forces experienced by the portable object excluding gravity divided by the mass of the portable object.

[0012] In a preferred alternative embodiment, the portable item further comprises an angular velocity sensor (gyrometer), the reliability index being determined by a function given to measurements of angular velocity made, preferably intermittently, by said angular velocity sensor, advantageously formed by a microelectromechanical system (MEMS).

[0013] The present invention will now be described in more detail by way of example with reference to the accompanying drawings, in which: [Brief description of the drawings]

[0014] [Figure 1] 1 shows a schematic diagram of a watch according to one preferred embodiment of the present invention; [Diagram 2] We show the trajectory TF(X) that the rocket will follow during its flight in space, from takeoff to the passage of the Kármán line LK, and the various variables associated with the flight along this trajectory and the method for detecting the passage of the Kármán line. [Diagram 3] It shows an enlarged view, enlarged compared to FIG. 2, of the vector sum of the various accelerations involved in the advantageous detection method. This method makes it possible to measure the specific acceleration of the watch. The orthogonal axes Xt and Zt are parallel to the X-axis and Z-axis of FIG. 2 and have their origin at a point PS(t) on the trajectory TF(x) of the rocket of interest. This point PS(t) defines the altitude HF(t). [Figure 4] Illustrates the theoretical curves of motion acceleration for a particular type of rocket as a function of time. [Diagram 5] 3 shows a theoretical curve of the rocket's inclination angle over time. [Figure 6] 1 shows a theoretical curve of the altitude of a rocket over time, which defines the theoretical flight time from take-off of the rocket to crossing the Karman line. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] In the following, with reference to the drawings, an advantageous embodiment of the watch according to the invention, an advantageous method for detecting the passage of a Kármán line by the watch according to the invention, and a method for verifying the detection of the passage of a Kármán line according to the invention will be described.

[0016] The watch 2 comprises a memory 4, a time base and a detection and verification 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"), which is particularly adapted to process the measurement results provided by the acceleration sensor 8. The watch 2 further comprises an electronic control unit 14, which is particularly adapted to activate the detection and verification 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 arranged on the case 20 at the outside of the case 20. It should be noted that the watch may comprise tactile control means, in particular a tactile crystal covering the display means, such tactile control means being provided, for example, for inputting data into the memory 4 of the watch and / or for controlling the display of certain data by the display means, in particular before or after a space flight or mission. In a particular alternative embodiment, the watch comprises an analogue display formed by hands associated with a scale and a digital display formed by an electronic display module defining the majority of the face of the watch.

[0017] The electronic unit 12, in conjunction with the acceleration sensor 8 and the memory 4, calculates, at least for a given type of rocket, the Kármán line L, using only the wristwatches 2 on board this rocket. KThe detection is therefore carried out autonomously by a detection device included in the detection and verification device 6 of the watch during the detection phase of the detection method implemented by the watch. K is the given altitude H D or an altitude H that can be selected by the user directly or via the selection of another spatial variable within a given range of values, in particular within the range of 85 to 110 km S The term "given altitude" should be understood to mean an altitude that is predefined / predetermined not by the user but by the watch manufacturer or by any authorized person or company.

[0018] Using a portable watch 2 on board the rocket, the rocket is measured at a given altitude H D or the selected altitude H S or for a given type of rocket 22, the Kármán line L K An advantageous method for detecting the passage of the timepiece is that the acceleration sensor 8 detects the acceleration vector a M * It is assumed that the electronic unit 12 is configured to measure the intrinsic acceleration vector a M * is the acceleration vector a of the watch at any instant / any time t, as a first approximation of the rocket. * from gravitational acceleration vector a E * minus the mass of the object. Note that 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. The intrinsic acceleration vector of a watch is equal to the vector sum of the forces experienced by the watch, with the exception of gravity, divided by its mass. That is, the intrinsic acceleration of an object is the acceleration that this object experiences relative to an observer when in free fall.

[0019] The detection method includes a preliminary stage, prior to the deployment of the portable object on board a rocket for a planned space flight, which includes the following preliminary steps: A) Determine time 0 by finding at least one Karman line L from the launch of the rocket. 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 acceleration) with units equal to the gravity of the Earth (hence this dimensionless scalar value corresponds to the norm of the vector of the nominal motion acceleration divided by the norm of the gravity of the Earth). B) A given altitude H from the launch 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). C) A given altitude H from the launch of the rocket D The theoretical flight time T for 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 inclination angle. PT (t), the value of which is a theoretical specific acceleration, in units equal to the Earth's gravity, defined by the formula:

[0020] TIFF0007663739000001.tif15170

[0021] E) Time 0 (t=0) corresponding to the rocket's 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, MTby 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 C A 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, the reference distance D MR This is the step to obtain

[0022] Thereafter, the detection method includes a detection stage which includes several detection steps: G) Activating the detection device of the watch on board the rocket prior to take-off of the rocket. 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 the take-off of the rocket or at least from 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.

[0023] The term "kinetic acceleration" is understood to mean the acceleration corresponding to the time derivative of the velocity, which always defines a vector tangential to the trajectory of the rocket, and therefore of the portable object, in space, i.e. a vector collinear with the rocket's temporal direction vector. The term "nominal" is understood to mean a value given in the specifications of the rocket type or of the particular rocket in question, which is therefore a theoretical value, in the context of the 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.

[0024] 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.

[0025] Regarding step A), as shown in the graph in Figure 4, the theoretical motion acceleration A N (t) can be negative temporarily, i.e. the rocket's speed can decrease temporarily. Therefore, the nominal kinetic acceleration is given with its mathematical sign and needs to be substituted with this mathematical sign in the formula given in step D).

[0026] With respect to step B) of this detection method, FIG. 5 shows the theoretical inclination angle θ of the rocket of interest as a function of time. T The figure shows an example of a curve for time T(t). B This rocket will continue to fly at time 0 and time T B Between them, the theoretical inclination angle θ T Follow the vertical direction so that (t) is 90°.

[0027] 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 It is defined by the tangent at (x), where the variable x is a function of time.

[0028] Theoretical flight time T KWith regard to step C) relating to, in a simplified alternative embodiment, it is possible to estimate this theoretical flight time on the basis of at least one previous space flight with a rocket of the type of interest. In one advantageous alternative embodiment, 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) should be used as the basis for 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 is dH FT (t)=dL T (t) sinθ T (t), where dH FT (t) is the infinitesimal / single-dimensional variation in 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 / unitary variation in time. Considering that velocity is equal to the integral of acceleration with respect to time, the nominal speed V N (t) is the nominal motion acceleration A N (t) can be mathematically and / or numerically determined. Therefore, based on the above mathematical relationship, the theoretical altitude H FT Infinitesimal / single-dimensional variation of (t) dH FT We can define (t) as a function of the given (nominal / theoretical) variables, which gives us: dH FT (t)=V N (t) sinθ T (t)·dt Where:

[0029] TIFF0007663739000002.tif16170

[0030] 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, the formula, H FT (T)=H D is solved, where H D is a given altitude and T is a variable.

[0031] 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.

[0032] 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 MT and a comparison distance, which is then precisely calculated in the electronic unit of the watch, can be compared on the basis of measurements of the intrinsic accelerations given by an acceleration sensor 8 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 a measurement means for detecting the passage of its Kármán line, only an acceleration sensor arranged to be able to measure the vector of intrinsic 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 MTIt is a fictitious theoretical distance, since it corresponds not 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 norm of the intrinsic acceleration, a reference value that depends only on the rocket's trajectory, is given, a vector in the coordinate frame of the watch 2 given by the acceleration sensor, which is advantageously corrected by the norm of the acceleration of gravity, this correction being carried out by subtracting the norm of the acceleration of gravity from the norm of the intrinsic acceleration. The passage of the Kármán line is therefore intended to be 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.

[0033] 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 minus the norm of the acceleration of gravity will 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 a 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 vertically oriented and is independent of the rocket's position in space. Note that the small centripetal acceleration experienced by the rocket as it tilts gradually is not taken into account in the relationship between the rocket's intrinsic acceleration, which includes this 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.

[0034] 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

[0035] Although the detection of the passage of the Kármán line by a wristwatch, which for the reasons described in the summary of the invention is advantageously adapted to implement the above detection method, is reliable as long as the detection device is activated during the space flight, preferably shortly before take-off, this detection method nevertheless has the major challenges mentioned above. In fact, the above-described advantageous detection method uses a 3D accelerometer, advantageously of MEMS type, as the only sensor it comprises to detect the passage of the Kármán line. However, such detection can give erroneous results in certain circumstances.

[0036] In general, the method for verifying the detection of the passage of the Kármán line defined by the predetermined altitude is implemented by a portable article by a user and is configured to measure the acceleration of the portable article during a detection phase of the method for detecting the passage of the Kármán line implemented by the portable article and to process these acceleration measurements in an electronic unit to enable the detection of the passage of the Kármán line by the portable article based on these acceleration measurements and on data recorded in the portable article before the detection phase of the detection method. According to one general implementation, the method for verifying the detection of the passage of the Kármán line utilizes sequential measurements made by the portable article during the detection phase of the method for at least one variable dependent on at least one force applied to the portable article. The verification method is executed by an electronic unit, which calculates at least one confidence index related to the sequential measurements and checks whether at least one given condition for the at least one confidence index is fulfilled to validate or invalidate the detection of the passage of the Kármán line by the portable article.

[0037] In the following, three specific confidence indices are described, whereby the detection of the passage of the Kármán line by the watch can be enabled or disabled using conditions, each of which is given for at least one of said confidence indices that are checked during the verification process.

[0038] The first confidence index C1(N) is determined by the following function:

[0039] TIFF0007663739000003.tif18170

[0040] N is the number of acceleration measurements taken during the detection phase of the detection method of interest, and A j is the acceleration value provided by the acceleration sensor during the j-th acceleration measurement or calculated in the electronic unit on the basis of this j-th acceleration measurement, where j=1 to N. The value L1 is the acceleration value Aj is the given limit of

[0041] This delta function gives the value "1" if the corresponding condition is true / fulfilled and the value "0" if the condition is false / not fulfilled. C1(N) therefore has a value between "0" and "1". The closer the value of the function C1(N) is to "1", the greater the confidence in detecting the passage of the Kármán line.

[0042] The second confidence index C2(N) is determined by the following function:

[0043] TIFF0007663739000004.tif18170

[0044] N is the number of acceleration measurements taken during the detection phase of the detection method of interest, and V q is the value A j It is the velocity obtained by numerically integrating over time the acceleration determined by (j=1 to q). The value L2 is a given limit for said velocity. C2(N) also has a value between "0" and "1". The closer the value of the function C2(N) is to "1", the greater the confidence.

[0045] In particular, after q successive measurements made at a frequency F equal to 1 / P, the velocity V q Incremental integration can be used to determine the velocity V q is the increase in velocity over the time interval q P when these q successive measurements are taken. Thus, the velocity V q is given by the following formula:

[0046] TIFF0007663739000005.tif18170

[0047] The third confidence index C3(M) is determined by the following function:

[0048] TIFF0007663739000006.tif17170

[0049] M is the number of angular measurement measurements made by the angular velocity sensor (gyrometer) incorporated for this purpose in the watch during the detection phase of the detection method of interest. k is the value of the acceleration given by the angular velocity sensor during the k-th angular velocity measurement or calculated based on the k-th (k=1 to M) measurement. The value L3 is the value W k The function C3(M) takes values ​​between "0" and "1". The closer the value of the function C3(M) is to "1", the greater the confidence in detecting the passage of the Kármán line.

[0050] It should be noted that, according to three basic alternative embodiments, the verification method according to the invention is related to a single confidence index of the three confidence indexes and to a corresponding given condition that is verified at least after the detection of the passage of the Kármán line by the watch. In this basic alternative embodiment related to the third confidence index, the angular velocity sensor 10 is also integrated in the watch and associated with the detection device to form a detection and verification device capable of implementing said verification process. The given condition checks whether the third confidence index C3(M) is greater than a reference value R2 chosen in the range "0.5" to "1". In one preferred alternative embodiment, the reference value R2 is chosen in the range "0.7" to "0.9" (boundaries included). In a particular case, the value L3 is 200 rad / s and the reference value R2 is 0.8.

[0051] In one advantageous alternative embodiment, to be more secure, the verification method is related to a first and a second confidence index and also to the same given condition for these first and second confidence indexes. In a particular case, this same given condition is a condition for the average of the first and second confidence indexes. This same condition checks whether said average is greater than a first reference value R1, chosen within the range "0.5" to "1". In one preferred alternative embodiment, the first reference value R1 is chosen within the range "0.7" to "0.9" (boundaries included). In the particular case where the rocket is of a particular given type, the value L1 is chosen within the range "0.7" to "0.9", bounds included. ... 2 where the value L2 is 1000 m / s and the reference value R1 is 0.8.

[0052] In a particular alternative embodiment, particularly related to the advantageous detection method described above, the acceleration sensor 8 measures the intrinsic acceleration vector of the portable object in the coordinate frame of the watch, said acceleration value A j is the norm of the intrinsic acceleration vector minus the norm of the gravitational acceleration, such that this intrinsic acceleration vector is obtained during the j-th acceleration measurement. Note that the intrinsic acceleration vector of the watch is equal to the vector sum of the forces experienced by the watch, excluding gravity, divided by its mass. In this case, the acceleration sensor is a microelectromechanical system (MEMS).

[0053] In one advantageous alternative embodiment, the verification method is related to three confidence indices and at least one given condition is related to these three confidence indices. In one advantageous alternative embodiment, the verification method is related to three confidence indices and provides a first given condition related to the first and second confidence indices and a second given condition related to the third confidence indices. Thus, as long as these two given conditions are fulfilled, verification of the detection of the passage of the Kármán line is obtained. In a particular case, the first condition is identical to the condition for the average of the first and second confidence indices and the second condition is identical to the condition in the basic alternative embodiment related to the third confidence indices, also given above. Thanks to this preferred alternative embodiment, it is possible to eliminate erroneous results (false positive results) in all of the particular situations listed in the invention summary, in particular for the axial projection 115.

[0054] In a preferred alternative embodiment, the angular velocity sensor is formed by a microelectromechanical system (MEMS). In the summary of the invention, it was mentioned that MEMS-type angular velocity sensors are not precise and are not suitable for correctly detecting the passage of the Kármán line. The invention does not ignore this. However, the inventors have found that such angular velocity sensors can nevertheless provide data that is precise enough to be used in the method for verifying the detection of the passage of the Kármán line according to the invention. The passage of the Kármán line is therefore intended to be detected without a gyrometer measurement, the detection in this case being subsequently verified with a gyrometer measurement. The accuracy of the gyrometer here is relatively unimportant when verifying such a detection by eliminating false positives in situations with relatively high central forces.

[0055] The invention further relates to a portable article for space applications, in particular a portable watch 2, portable and portable, which comprises a detection device formed by an acceleration sensor 8, a time base and an electronic unit 12, which is adapted to measure, preferably intermittently, the acceleration of the portable article by means of the acceleration sensor 8. The detection device is adapted to autonomously detect, during a space flight of a rocket, a passage of a Kármán line, defined by a given altitude, by the portable article, by processing in the electronic unit at least the acceleration measurements made during the space flight. The detection device then forms part of a detection and verification device 6, which is also adapted to implement a method for verifying the detection of the passage of a Kármán line according to the invention.

[0056] In a preferred embodiment, the portable object, in particular the watch 2, further comprises an angular velocity sensor 10, which is associated to the detection device so as to implement a verification method according to a preferred alternative embodiment. The electronic unit 12 is also adapted to implement a method for verifying the detection of the passage of the Kármán line by the watch, which verification method makes use of a confidence index related to the angular velocity, in particular a third confidence index and a given condition related thereto. In this way, the detection device has been developed within the scope of the invention so as to also be a device for detecting each detection. More specifically, the device 6 comprises a part for the actual detection of the passage of the Kármán line and a part for the verification of such a detection, these two parts sharing hardware resources, in particular the electronic unit. The device 6 is therefore a device for detecting the passage of the Kármán line and also for verifying each detection. An angular velocity sensor is not provided and therefore not used in the detection part specifically designed to detect the passage of the Kármán line. However, in the part verifying each detection, an angular velocity sensor 10 is advantageously provided.

[0057] In one advantageous alternative embodiment, the angular rate sensor 10 is formed from a micro-electromechanical system (MEMS). [Explanation of symbols]

[0058] 2 Portable items 4. Memory 6. Detection and Verification Devices 8. Accelerometer 10 Angular velocity sensor 12 Electronic Unit 16, 17 Push button 18 Stem crown 20 cases

Claims

1. 1. A method for verifying detection of a passage of a Kármán line, defined by a predetermined altitude, by a portable object that can be carried by a user, comprising: said portable article comprising a detection device formed by an acceleration sensor, a time base and an electronic unit; the detection device is adapted to measure accelerations experienced by the portable article during a detection phase of a method for detecting the passage of a Kármán line implemented by the portable article, and to process these acceleration measurements in the electronic unit, This allows detection of the passage of a Kármán line by the portable object based on the measurements of their acceleration and on data recorded on the portable object prior to the detection step of the method for detection, the verification method utilizing sequential measurements made by the hand-held article during the detection step of the method for detecting, for at least one variable dependent on at least one force applied to the hand-held article; The verification method is performed by an electronic unit, The electronic unit calculates at least one confidence index associated with the sequential measurements and checks whether at least one condition for the at least one confidence index is fulfilled to validate or invalidate the detection of the passage of the Kármán line by the portable item. A method comprising:

2. The confidence index is determined by the following function: where is the number of acceleration measurements taken, C1(N) is the confidence index for N measurements, A j is the acceleration value provided by the acceleration sensor during the j-th acceleration measurement or calculated in the electronic unit on the basis of this j-th (j=1 to N) acceleration measurement, L1 is the acceleration value A j is a given limit on The delta function gives a value of "1" if the corresponding condition is true, and a value of "0" if the condition is false, so C1(N) will have a value between "0" and "1".

2. The method of claim 1 .

3. the confidence index is a first confidence index; The function is a first function, the given condition is a first given condition, said electronic unit furthermore calculates a second confidence index determined by a second function applied to said acceleration measurements and verifies said first given condition if said first given condition is also related to the second confidence index, and verifies a second given condition otherwise, to enable or disable detection of the passage of a Kármán line by said portable object; The second confidence index is determined by the following function: C2(N) is the second confidence index for the N acceleration measurements taken, its value being between "0" and "1"; V q is the value A j is the velocity obtained by numerically integrating over time the acceleration determined by (j=1 to q), The value L2 is a limit given to the speed 3. The method of claim 2 .

4. The first given condition is related to the first confidence index and the second confidence index, and the processing of the acceleration measurements performed by the electronic unit results in N K after obtaining the acceleration measurement results, verifying at least that the portable article has passed the Kármán line, to validate or invalidate this result, the first given condition is a condition on an average of the first confidence index and the second confidence index; This condition is met if the average is greater than a first reference value R1, which is chosen within the range of "0.5" to "1" (boundaries included).

4. The method according to claim 3 .

5. the acceleration sensor measures a characteristic acceleration vector of the portable object in the coordinate frame of the portable watch; The acceleration value A j is the norm of the intrinsic acceleration vector obtained during the j-th acceleration measurement minus the norm of the gravitational acceleration, The intrinsic acceleration vector of the portable item is equal to the vector sum of the forces acting on the portable item, excluding gravity, divided by the mass of the portable item. The method according to any one of claims 2 to 4.

6. The acceleration sensor is formed by a microelectromechanical system (MEMS).

6. The method of claim 5 .

7. The portable article further includes an angular velocity sensor; The confidence index is determined by a function given to the angular velocity measurements made by the angular velocity sensor during the detection phase of the method for detecting.

2. The method of claim 1 .

8. The confidence index is determined by the following function: where C(M) is the confidence index for the M angular velocity measurements taken, W k is the value of the angular velocity provided by the angular velocity sensor during the k-th angular velocity measurement or calculated in the electronic unit based on the k-th (k=1 to M) measurement, The value L3 is the value W k is the given limit of The delta function gives a value of "1" if the corresponding condition is true, and a value of "0" if the condition is false, so C3(M) has a value between "0" and "1".

8. The method of claim 7.

9. The given condition is satisfied if the confidence index is greater than a reference value R2, selected within the range of "0.5" to "1" (boundaries included).

9. The method of claim 8.

10. The portable article further includes an angular velocity sensor; The verification method includes calculating another confidence index, determined by a given function for the angular velocity measurements made by the angular velocity sensor during the detection phase of the method for detection, and verifying at least one condition given for the other confidence index to validate or invalidate the detection of the passage of the Kármán line by the portable object. The method according to any one of claims 2 to 4.

11. The confidence index is determined by the following function: where C(M) is an additional confidence index for the M angular velocity measurements taken, W k is the value of the angular velocity provided by the angular velocity sensor during the k-th angular velocity measurement or calculated in the electronic unit based on the k-th (k=1 to M) measurement, The value L3 is the value W k is the given limit of The delta function gives a value of "1" if the corresponding condition is true, and a value of "0" if the condition is false, so C3(M) has a value between "0" and "1".

11. The method of claim 10.

12. The given condition for the additional confidence index is met if the additional confidence index is greater than a second reference value R2, selected within the range of "0.5" to "1" (boundaries included).

12. The method of claim 11 .

13. The angular velocity sensor is formed by a microelectromechanical system (MEMS). The method according to any one of claims 7 to 9.

14. Said portable object (2) is capable of being carried by a user and comprises a detection device formed by an acceleration sensor (8), a time base and an electronic unit (12), The detection device is configured to measure the acceleration of the portable item using the acceleration sensor (8), the detection device is adapted to autonomously detect, during a space flight of a rocket, a passage of the portable article through a Kármán line, defined by a given altitude, by processing in the electronic unit at least acceleration measurements made during the space flight; said detection device forming part of a detection and verification device (6), This detection and verification device (6) is also adapted to be able to implement the method according to any one of claims 1 to 4. A portable item (2).

15. The acceleration sensor (8) is formed by a microelectromechanical system (MEMS). Portable item (2) according to claim 14.

16. The detection and verification device (6) further comprises an angular velocity sensor (10), The electronic unit (12) is adapted to be able to implement the method according to any one of claims 7 to 9. Portable item (2) according to claim 14.

17. The detection and verification device (6) further comprises an angular velocity sensor (10), The electronic unit (12) is adapted to be able to implement the method according to any one of claims 7 to 9. Portable item (2) according to claim 15.

18. The angular velocity sensor is formed by a microelectromechanical system (MEMS).

17. Portable item (2) according to claim 16.

19. The angular velocity sensor is formed by a microelectromechanical system (MEMS).

18. Portable item (2) according to claim 17.

20. It is a portable watch (2). Portable item (2) according to claim 14.

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