• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    The general field of the invention is that of devices for measuring an inertia parameter. The device according to the invention comprises a first sensor (20) of the electromechanical microsystem type operating at a first frequency and a second cold atom device type sensor operating at a second frequency lower than the first measurement frequency. The device according to the invention further comprises a comparison electronics comprising: first computing means operating at the second frequency and calculating, from a first measurement from the first sensor and a second measurement from the second sensor, a bias between said first measure and said second measure and; second computing means operating at the first frequency, and calculating measurements of said inertia parameter, each of said calculated measurements being equal to a first measurement from the first corrected sensor of said bias. This type of device is well suited to the realization of inertial units.
    公开号:FR3031187A1
    申请号:FR1403026
    申请日:2014-12-30
    公开日:2016-07-01
    发明作者:Sylvain Schwartz；Matthieu Dupont-Nivet
    申请人:Thales SA；
    IPC主号:
    专利说明:

    [0001] FIELD OF THE INVENTION The field of the invention is that of inertial navigation. The purpose of an inertial unit is to provide the angular velocity and acceleration information of a moving vehicle. The preferred field of application is aeronautics.
    [0002] An inertial unit therefore includes gyrometers and accelerometers to ensure the necessary measurements. There are currently two categories of inertial units, depending on the required levels of performance and space requirements. High-end inertial units are generally based on optical gyrometers. They have the disadvantage of having a size that can be important, even prohibitive for some applications. Inertial units based on micro-electromechanical sensors, also called "MEMS", acronym meaning "Micro Electro Mechanical Systems", are significantly smaller in size compared to optical technologies. However, these sensors have significant levels of bias drift. Typically, the drift is of the order of degree per hour for the best MEMS gyrometers, which limits their applications to the areas of bass and average performance. Further information on this type of MEMS can be found in the publication "Performance of MEMS inertial sensors" by Kourepenis et al, published in IEEE PLANS April 1998. Highly stable inertial sensors over the long term have been developed in recent years using Atomic interferometry techniques with laser cooled atoms. It is now possible to make this type of sensor in a small footprint. The atoms are then trapped in the vicinity of a substrate or "atomic chip" throughout the detection cycle. An architecture of this type potentially has, compared to sensors using cold atoms in free fall, the advantages of a great compactness. However, the cold atomic sensors have a reduced level of bandwidth, typically of the order of the hertz. Indeed, the measurement accuracy depends on the separation time of the cold atoms which can hardly be reduced without affecting the accuracy of the measurement. However, for some applications, this measurement rate is too low. In the publication "Hybridizing matter-wave and classical accelerometers" by Lautier et al, published in Applied Physics Letters 1054141410 (2014), the hybridization of an accelerometer and an atomic gravimeter has been proposed. In the hybridization described, the accelerometer is used to slave the reflecting mirror of an atomic gravimeter operating by interferometry. This arrangement makes it possible to obtain both a high measurement accuracy and a larger bandwidth than that of a non-controlled gravimeter. However, this application is limited to gravimetry with free falling atoms and can not easily be applied to the measurement of other inertial parameters. Moreover, this device remains a laboratory device. Finally, this device has the disadvantage of slaving the complex system of a cold atomic sensor.
    [0003] The device for measuring an inertial parameter according to the invention is also a hybrid device that combines both a microelectromechanical sensor and a cold on-chip sensor. However, it can be applied to all types of MEMS and cold atom sensors as this device is not dedicated to a particular parameter or technology. By combining measurements of the same inertial parameter made by two sensors of different nature, one obtains both the precision of the cold atom systems and the bandwidth of the MEMS sensors. More specifically, the subject of the invention is a device 25 for measuring an inertia parameter comprising a first sensor for measuring said inertia parameter, said first sensor being an electromechanical microsystem operating at a first frequency, characterized in that said measuring device comprises: a second sensor for measuring said inertia parameter, said second sensor being a cold-atom device operating at a second measurement frequency lower than the first measurement frequency, and; a comparison electronics comprising: first computing means operating at the second measurement frequency and calculating, from a first measurement from the first sensor and a second measurement from the second sensor, a bias between said first measure and said second measure and; second computing means operating at the first measurement frequency, and calculating measurements of said inertia parameter, each of said calculated measurements being equal to a first measurement from the first corrected sensor of said bias. Advantageously, the bias correction is an electronic correction performed by the second calculation means. Advantageously, bias correction is achieved by modifying one or more physical parameters of the first sensor. Advantageously, the physical parameters are the voltages of the control electrodes of the electromechanical microsystem. Advantageously, the physical parameter is the temperature of the electromechanical microsystem.
    [0004] Advantageously, the second sensor comprises an electronic chip comprising parallel conductive wires and means for powering said conductor wires, the cloud of cold atoms necessary for the measurement being disposed in the vicinity of said electronic chip, the conductive wires and their feeding means being arranged to create the electromagnetic fields necessary for the superposition of internal states of the atoms, their separation and their recombination. Advantageously, the first sensor is implanted on said electronic chip.
    [0005] Advantageously, the electronic chip is arranged to measure at least one second inertia parameter. Advantageously, the inertia parameter is either an acceleration or a rotational speed. The invention also relates to an inertial unit 30 comprising three accelerometers arranged to measure acceleration in three non-coplanar space directions and three gyrometers arranged to measure the speed of rotation in three directions of space not coplanar. At least one of the accelerometers or one of the gyrometers of said inertial unit is a device for measuring an inertia parameter as described above.
    [0006] Advantageously, the three accelerometers and the three gyrometers are devices for measuring an inertia parameter as described above.
    [0007] The invention will be better understood and other advantages will become apparent on reading the description which will follow given by way of nonlimiting example and with reference to the appended figures among which: FIG. 1 represents the block diagram of a measuring device of a inertia parameter according to the invention comprising two inertia sensors; FIG. 2 represents a view of an implantation of the two inertia sensors on the same electronic chip. By way of example, FIG. 1 represents the block diagram of a device for measuring an inertia parameter according to the invention. In this figure, the devices are shown boxed and the arrows represent the direction of transmission of the information. The measuring device essentially comprises: a first sensor of the electromechanical microsystem type measuring said inertia parameter. This sensor operates at a first frequency F1 and we note M1 (t) the measurements from this sensor as a function of time t; a second cold atom device sensor also measuring said inertia parameter. This sensor operates at a second measurement frequency F2 lower than the first measurement frequency F1.
    [0008] Typically, F2 is of the order of Hertz. M2 (t) measures the measurements from this sensor as a function of time t; - A comparison electronics that has two functions. Its first function is to compare at a rate that is that of the second frequency, the measurements from the first and the second sensor. Its second function is to calculate a measurement of the inertia parameter at the first frequency. It is known that, by nature, the cold atom devices give measures of great stability. Therefore, at an instant of measurement, the measure M2 (to) is considered an exact measure of the parameter. Generally, the first sensor being less precise than the second, its measurement M1 (to) at this instant to is different from M2 (to). We call B (to) the bias that exists between these two measures and we have the simple relation: M2 (to) = M1 (to) + B (to) Between this first measurement made at time to and the next measurement 5 realized by the second sensor, a period of time T2 which is worth 1 / F2 flows. With a measurement rate at 1 Hertz, T2 is 1 second. During this period T2, even if the first sensor drifts, its bias remains practically constant. Thus, it can be considered that at any time t chosen between to and to + T2, the measurement from the first sensor is accurate provided that it is corrected for bias B (to). We can then write, by noting MvRA1E (t) the exact measurement at time t: MvRAIE (t) = M1 (t) + B (to) Thus, the knowledge of the bias at the frequency F2 allows, from the measurement made by the first sensor to know the true measurement at the frequency F1 which can be much larger than the frequency F2 and which is limited only by the characteristics of the MEMS sensor. Bias correction can be done electronically. The bias between the two sensors is periodically calculated and taken into account in the calculation of the final measurement. It can also be obtained by modifying one or more physical parameters of the first sensor. It is thus possible to act on the voltages of the control electrodes of the electromechanical microsystem or to regulate its temperature so as to reduce the bias to near zero.
    [0009] The cold atom device may be of different natures. However, it is interesting to focus on compact architectures, for example with trapped atoms, in particular on electronic chips that allow the integration of the MEMS sensor on the same electronic chip.
    [0010] A cold atomic sensor of this type comprises a central part consisting of a vacuum chamber, all the walls of which are transparent, except the upper wall which consists of a chip on which conductor wires have been deposited. This chip 10 is shown in the perspective view of FIG. 2. In the case of FIG. 2, the measured inertial parameter is the acceleration whose direction is symbolized by four chevrons in FIG. 2. In this version, the Electronic chip 303 1 1 8 7 6 also includes the MEMS sensor 20 which is in this case an accelerometer. The measurement atoms, initially in the gaseous phase at ambient temperature in the chamber, are trapped and cooled with six laser beams arranged symmetrically two by two on three axes perpendicular two by two combined with a field gradient. magnetic generated by external magnetic coils. The six laser beams are arranged symmetrically on three perpendicular axes. The set of laser beams and magnetic coils is called three-dimensional magneto-optical trap or "3D PMO". At the end of the cooling and trapping phase, the atoms are transferred into a purely magnetic conservative trap created in the vicinity of the conductive wires of the chip 10 and prepared in an internal state, for example 11>. At the end of this phase, the atoms are situated at an initial spatial position above the electronic chip 10. As seen in FIG. 2, the electronic chip 10 comprises at least a first central conducting wire 11 used as the main trapping wire, a second conductive wire 12 perpendicular to the first wire and used as a secondary trapping wire, two lateral waveguides 13 parallel to each other, parallel to the secondary trapping wire 12 and arranged symmetrically with respect thereto. this. The atomic cloud 15 is located above the first conductive wire 11, said first conductor wire being traversed by a first current and generating a magnetostatic field, the first waveguide 13 being traversed by a second current modulated at a magnetic current. second microwave frequency generating a second microwave field and the second waveguide 13 being traversed by a third current modulated at a third microwave frequency, generating a third microwave field. This arrangement makes it possible to separate and recombine magnetically the atomic cloud. The separation-recombination method is detailed below. In a first step, the atoms are transferred in an equal weight superposition of the internal states 11> and 12>, by a pulse of short duration called pulse 7c / 2 combining a microwave field and a radiofrequency field generated, for example, by the conductive lines 13 of the chip 10. Each atom is then in a resulting intermediate state noted (11> + 12>) / '12.
    [0011] In a second step, the atoms are separated into two wave packets associated with internal states 11> and 12>, thanks to a microwave potential MW depending on the internal state. It is this atomic separation phase which is shown in FIG. 2. The microwave field used for the separation is generated by the two coplanar waveguides or CPW 13. The separation is in the direction of the acceleration so as to be as sensitive as possible. The separation distance s of the atoms is of the order of one or more tens of micrometers. Separation during a time Ts causes a phase shift between the two wave packets related to the local acceleration. In a third step, the atoms are recombined by the suppression of the applied microwave fields. The phase shift is then converted to a population difference between the internal states by means of a second pulse "7r / 2".
    [0012] The atomic cloud is detected using the absorption imaging technique of measuring with a CCD camera the absorption of a quasi-resonant laser beam by the atomic cloud. Optical spectroscopy thus gives access to the populations of the two internal states, thus to the desired phase shift. Alternatively, the populations of the two internal states can be measured by fluorescence using photodiodes. Finally, the acceleration is calculated, which is then compared to that obtained by the MEMS accelerometer. The device according to the invention combining two types of sensors 25 makes it possible to measure accelerations and speeds of rotation at a large measurement rate and with a high accuracy. An inertial unit has three acceleration sensors and three rotation sensors. An inertial unit can be made from this type of measuring device, either totally or partially. One of the advantages of the cold electrode sensors on an electronic chip is that, not only is it possible to integrate on the same chip one or more MEMS but it is also possible to measure with the same chip different inertia parameters according to the electromagnetic fields generated in the conductive wires. This considerably simplifies the construction of the inertial unit 35.
    [0013] The industrial applications of this inertial unit concern in particular devices requiring precision inertial guidance in environments where the "GPS", acronym for "Global Positioning System" may be absent for relatively long times, of the order of several tens of minutes. Such lack of GPS may be accidental due, for example, to poor reception or intentional, the GPS signal is then scrambled.
    权利要求:
    Claims (11)
    [0001]
    REVENDICATIONS1. Device for measuring an inertia parameter comprising a first measurement sensor (20) of said inertia parameter, said first sensor being an electromechanical microsystem operating at a first frequency, characterized in that said measuring device 5 comprises: a second sensor for measuring said inertia parameter, said second sensor being a cold atom device operating at a second measurement frequency lower than the first measurement frequency, and; A comparison electronics comprising: first computing means operating at the second measurement frequency and calculating, from a first measurement from the first sensor and a second measurement from the second sensor, a bias between said first measurement and said second measure and; Second computing means operating at the first measurement frequency, and calculating measurements of said inertia parameter, each of said calculated measurements being equal to a first measurement from the first corrected sensor of said bias. 20
    [0002]
    2. Device for measuring an inertia parameter according to claim 1, characterized in that the bias correction is an electronic correction performed by the second calculation means.
    [0003]
    3. Device for measuring an inertia parameter according to claim 1, characterized in that the bias correction is obtained by a modification of one or more physical parameters of the first sensor.
    [0004]
    4. A device for measuring an inertia parameter according to claim 3, characterized in that the physical parameters are the voltages of the control electrodes of the electromechanical microsystem. 3031187 10
    [0005]
    5. Device for measuring an inertial parameter according to claim 3, characterized in that the physical parameter is the temperature of the electromechanical microsystem.
    [0006]
    6. Device for measuring an inertia parameter according to one of the preceding claims, characterized in that the second sensor comprises an electronic chip (10) having parallel conductive son (12, 13) and feeding means said conductive son, the cloud of cold atoms necessary for the measurement being disposed in the vicinity of said electronic chip, the conductive son and their supply means being arranged to create the electromagnetic fields necessary for the superposition of internal states atoms, their separation and their recombination.
    [0007]
    7. Device for measuring an inertia parameter according to claim 6, characterized in that the first sensor (20) is implanted on said electronic chip.
    [0008]
    8. Device for measuring an inertia parameter according to claim 6, characterized in that the electronic chip is arranged to measure at least one second inertia parameter.
    [0009]
    9. Device for measuring an inertia parameter according to one of the preceding claims, characterized in that the inertia parameter is either an acceleration or a rotational speed.
    [0010]
    10. Inertial unit comprising three accelerometers arranged to measure the acceleration in three non-coplanar space directions and three gyrometers arranged to measure the speed of rotation in three non-coplanar space directions, characterized in that that at least one of the accelerometers or one of the gyrometers of said inertial unit is a device for measuring an inertia parameter according to one of the preceding claims. 3031187 11
    [0011]
    11. Inertial unit according to claim 10, characterized in that the three accelerometers and the three gyrometers are devices for measuring an inertia parameter according to one of claims 1 to 9.
    类似技术:
    公开号 | 公开日 | 专利标题
    Lautier et al.2014|Hybridizing matter-wave and classical accelerometers
    Dutta et al.2016|Continuous cold-atom inertial sensor with 1 nrad/sec rotation stability
    WO2016107806A1|2016-07-07|Hybrid inertia sensor employing cold atoms and mems and associated inertial platform
    EP2199742B1|2020-04-22|Matter-wave gyrometric and accelerometric sensor integrated on an atomic chip
    FR3048085B1|2019-07-19|ACCELEROMETER OF MAGNETIC LEVITATION WITH HIGH PRECISION
    EP2791620B1|2015-10-28|Measurement by means of atom interferometry
    Fang et al.2016|Metrology with atom interferometry: inertial sensors from laboratory to field applications
    FR2551552A1|1985-03-08|ANGULAR SPEED DETECTOR USING TWO VIBRANT ACCELEROMETERS FIXED TO A PARRALLELOGRAM
    WO2007002327A1|2007-01-04|Method for combining continuous and discontinuous inertial instrument measurements and inertial navigation system using the same
    FR2531481A1|1984-02-10|TRANSDUCER AND METHOD FOR DETECTING THE ANGULAR POSITION OF THE BODY OF A MEASUREMENT INSTRUMENT AND OF SURVEY CONTROL IN RELATION TO A REFERENCE POSITION
    EP3436779B1|2020-09-23|Device for measuring rotation, associated method and inertial navigation unit
    FR2939899A1|2010-06-18|INTEGRATED MATTER WAVE GRAVIMETER ON ATOMIC CHIP
    WO2018154254A1|2018-08-30|Hybrid inertial measurement system and method using a light pulse cold atom interferometer
    US9227840B2|2016-01-05|Micro-electro mechanical apparatus with PN-junction
    FR2478319A1|1981-09-18|LASER ROTATION SPEED SENSOR IN RING
    FR3021120A1|2015-11-20|GRAVIMETER WITH WAVES OF MATERIAL WITH MAGNETIC FIELD MICROWAVE SEPARATION
    WO2017093166A1|2017-06-08|Inertial navigation system with improved accuracy
    FR2951820A1|2011-04-29|METHOD AND DEVICE FOR LONG-TERM NAVIGATION
    WO2020084272A1|2020-04-30|Multi-axis atom interferometer system and method
    FR2729755A1|1996-07-26|Ring laser gyroscope with phase error correction
    FR2826446A1|2002-12-27|Gyrometer/accelerometer inertial value atomic interferometer having vacuum ballistic trajectory laser beam transmitting/separating trajectories and detecting recombined level with successive burst alternate directions
    WO2015044580A1|2015-04-02|Interferometric system with multiaxial optical fibre and method for processing an interferometric signal in such a system
    EP2267408B1|2012-06-06|Stabilised solid-state gyrolaser
    FR2877430A1|2006-05-05|Inertial magnitude measuring method for measuring speed of rotation, involves emitting puff of slow moving atoms from source along constant direction and opposite to direction, during presence of gravitational field
    Gao et al.2016|Improvement of atom interferometer by rejecting typical noise sources
    同族专利:
    公开号 | 公开日
    WO2016107806A1|2016-07-07|
    FR3031187B1|2017-10-20|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    US20100149541A1|2008-12-17|2010-06-17|Lockheed Martin Corporation|Performance of an Atom Interferometric Device through Complementary Filtering|
    EP2629303A1|2012-02-17|2013-08-21|Honeywell International Inc.|Atom interferometer with adaptive launch direction and/or position|
    EP2679953A1|2012-06-27|2014-01-01|Honeywell International Inc.|Closed loop atomic inertial sensor|
    WO2014145233A1|2013-03-15|2014-09-18|Johnson David M S|Ring architecture for sequential operation of an atomic gyroscope|
    FR2939884B1|2008-12-16|2012-07-27|Thales Sa|ATOMIC CHIP INTEGRATED MATERIAL WAVE GYROMETER AND ACCELEROMETER|
    FR2975218B1|2011-05-10|2013-05-17|Thales Sa|ATOMIC COOLING AND TRAPPING DEVICE|
    US20130152680A1|2011-12-15|2013-06-20|Honeywell International Inc.|Atom-based accelerometer|FR3060114B1|2016-12-13|2019-05-17|Commissariat A L'energie Atomique Et Aux Energies Alternatives|NAVIGATION ASSISTANCE METHOD, COMPUTER PROGRAM PRODUCT, AND INERTIAL NAVIGATION CENTER|
    WO2019134755A1|2018-01-08|2019-07-11|Siemens Aktiengesellschaft|Multi-axis sensor device|
    US11255672B2|2019-10-28|2022-02-22|Honeywell International Inc.|System having an extended life high performance sensor|
    法律状态:
    2015-11-23| PLFP| Fee payment|Year of fee payment: 2 |
    2016-07-01| PLSC| Publication of the preliminary search report|Effective date: 20160701 |
    2016-11-28| PLFP| Fee payment|Year of fee payment: 3 |
    2017-11-27| PLFP| Fee payment|Year of fee payment: 4 |
    2019-11-28| PLFP| Fee payment|Year of fee payment: 6 |
    2020-11-25| PLFP| Fee payment|Year of fee payment: 7 |
    2021-11-25| PLFP| Fee payment|Year of fee payment: 8 |
    优先权:
    申请号 | 申请日 | 专利标题
    FR1403026A|FR3031187B1|2014-12-30|2014-12-30|COLD ATOMIC HYBRID INERTIA SENSOR AND MEMS AND ASSOCIATED INERTIAL PLANT|FR1403026A| FR3031187B1|2014-12-30|2014-12-30|COLD ATOMIC HYBRID INERTIA SENSOR AND MEMS AND ASSOCIATED INERTIAL PLANT|
    PCT/EP2015/081115| WO2016107806A1|2014-12-30|2015-12-23|Hybrid inertia sensor employing cold atoms and mems and associated inertial platform|
    [返回顶部]