Disclosure of Invention
The invention provides a micro-electromechanical gyroscope calibration device and method and an unmanned aerial vehicle navigation system, which are used for correcting precision deviation of a micro-electromechanical gyroscope and improving reliability and accuracy of motion attitude estimation of the navigation system.
In a first aspect, an embodiment of the present invention provides a calibration apparatus for a micro-electromechanical MEMS gyroscope, where the calibration apparatus includes:
the system comprises an MEMS gyroscope, a main controller, a GPS processing module and at least three GPS antennas;
wherein the at least three GPS antennas are positioned on the sports equipment and are not positioned on the same straight line; the at least three GPS antennas are all connected with the GPS processing module; the MEMS gyroscope and the GPS processing module are electrically connected with the main controller; the at least three GPS antennas are used for acquiring position data of the sports equipment at a plurality of time points and sending the position data to the main controller through the GPS processing module; the MEMS gyroscope is used for acquiring real-time attitude data of the motion equipment at a plurality of time points and sending the real-time attitude data to the main controller; the main controller is used for calculating theoretical attitude data of the motion equipment according to the position data of the motion equipment and calibrating the MEMS gyroscope according to the theoretical attitude data and the real-time attitude data at the same time point.
In a second aspect, an embodiment of the present invention further provides a calibration method for a micro-electromechanical MEMS gyroscope, which is executed by the calibration apparatus for a micro-electromechanical MEMS gyroscope, and includes:
the at least three GPS antennas collect position data of the sports equipment at a plurality of time points and send the position data to the main controller through the GPS processing module;
the MEMS gyroscope is used for acquiring real-time attitude data of the motion equipment at a plurality of time points and sending the real-time attitude data to the main controller;
and the main controller calculates theoretical attitude data of the motion equipment according to the position data of the motion equipment and calibrates the MEMS gyroscope according to the theoretical attitude data and the real-time attitude data at the same time point.
In a third aspect, an embodiment of the present invention further provides an unmanned aerial vehicle navigation system, including:
a drone and the microelectromechanical MEMS gyroscope calibration apparatus of the first aspect;
the at least three GPS antennas of the MEMS gyroscope calibration device are located on the unmanned aerial vehicle.
According to the invention, the GPS antenna and the GPS processing module are introduced, the theoretical attitude data is calculated by utilizing the position data collected by the GPS antenna, and the error caused by the null shift of the MEMS gyroscope is corrected according to the real-time attitude data collected by the MEMS gyroscope, so that the reliability and the accuracy of the motion attitude estimation of the navigation system are improved.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.
Example one
Fig. 1 is a schematic diagram of a MEMS gyroscope calibration apparatus according to an embodiment of the present invention, where the MEMS gyroscope calibration apparatus includes aMEMS gyroscope 101, amain controller 102, aGPS processing module 103, and at least threeGPS antennas 104.
Wherein at least threeGPS antennas 104 are located on a sports device (not shown in fig. 1) and are not co-located on a straight line. The sports equipment is the sports equipment needing navigation, such as a unmanned aerial vehicle. The reason why the at least threeGPS antennas 104 are not located on the same straight line is that at least three pieces of position data containing various information need to be collected to calculate the theoretical attitude data. Because oneGPS antenna 104 can determine the position coordinates of only one point, the attitude of the aircraft can be determined only by acquiring the position coordinates of three or more points, and the three points are not collinear and coincident. Assuming all (at least 3) of theGPS antennas 104 on the aircraft are on the aircraft axis, the position coordinates collected by theseGPS antennas 104 will only determine the position and orientation of the aircraft axis, and when the aircraft rolls around the axis, the angle at which the aircraft rolls cannot be determined from these position coordinates, and the MEMS cannot be effectively calibrated. When the number of theGPS antennas 104 is 3, twoGPS antennas 104 may be respectively installed on two side wings of the main body of the unmanned aerial vehicle, and then oneGPS antenna 104 is installed on the tail wing of the unmanned aerial vehicle. ThreeGPS antennas 104 are exemplarily provided in fig. 1, which is not a limitation to the embodiment of the present invention, and in other embodiments, the number ofGPS antennas 104 may be specifically set according to actual requirements. At least threeGPS antennas 104 are connected with theGPS processing module 103; theMEMS gyroscope 101 and theGPS processing module 103 are electrically connected to themain controller 102. The at least threeGPS antennas 104 are used for acquiring position data of the sports equipment at a plurality of time points, and sending the position data to themain controller 102 through theGPS processing module 103.
TheGPS antenna 104 is provided with a sampling period, and acquires position data of the mobile device once in each sampling period, and then obtains high-precision position data by using a Real-time kinematic (RTK) method. The RTK method refers to the positioning of theGPS antenna 104 by the satellites being corrected by other reference systems (e.g., ground base stations) so that the acquired position data is more accurate.
TheGPS processing module 103 is configured to receive position data collected by at least threeGPS antennas 104, perform filtering, positioning, conversion processing, and packetize the data and send the data to themain controller 102.
TheMEMS gyroscope 101 is used for acquiring real-time attitude data of the motion device at multiple time points and sending the data to themain controller 102.
Themain controller 102 is configured to calculate theoretical attitude data of the motion device according to the position data of the motion device, and calibrate theMEMS gyroscope 101 according to the theoretical attitude data and the real-time attitude data at the same time point.
The real-time attitude data and the theoretical attitude data comprise a pitch angle, a yaw angle and a roll angle of the motion equipment.
The MEMS gyroscope calibration device provided by the embodiment of the invention adopts at least three GPS antennas to collect position data, then utilizes an RTK method to perform auxiliary correction on the obtained position data to improve the accuracy, the position data is processed by the GPS processing module and then is sent to the main controller, the main controller converts the position data into theoretical attitude data and calibrates the error caused by null shift of the MEMS gyroscope according to the real-time attitude data of the same time point provided by the MEMS gyroscope, and the accuracy and the reliability of a navigation system of the motion equipment are improved.
Themain controller 102 is provided with a calibration period, and themain controller 102 calculates theoretical attitude data of the motion device according to the position data of the motion device in the calibration period, and calibrates theMEMS gyroscope 101 according to the theoretical attitude data and the real-time attitude data at the same time point.
The calibration period can be set according to needs, the time can be long or short, and the MEMS gyroscope error can be corrected in time without influencing the navigation of the motion equipment.
The at least threeGPS antennas 104 collect the position data of the sports device at a plurality of points in time all the way through the operation of the sports device.
Because theGPS processing module 103 is independent and has an independent microprocessor to acquire and process signals and send the signals to themain controller 102, the amount of computation of the acquisition and processing of GPS signals is enormous, and the results are acquired and processed independently by the microprocessor of theGPS processing module 103 and then sent to themain controller 102, thereby greatly saving the computational load of themain controller 102. Therefore, theGPS processing module 103 and theGPS antenna 104 are a set of systems operating independently, and always acquire signals once power is supplied, without themain controller 102 controlling sampling and signal processing thereof by any enable signal.
In addition, theGPS processing module 103 generally has a necessary start time, and generally, the time required for the first start (commonly referred to as cold start) is as long as 10s, and the start interruption (hot start) also requires about 1s, so that the GPS keeps running at the moment, and the start time can be greatly reduced.
Themaster controller 102 also includes a MEMS data register and a GPS data register;
the MEMS data register is used for storing real-time attitude data of the motion equipment at a plurality of time points and corresponding time point information, which are acquired by the MEMSgyroscope 101;
the GPS data register is used to store the position data of the sports equipment at a plurality of time points collected by at least threeGPS antennas 104 and corresponding time point information.
Themaster controller 102 is also used to correct for signal acquisition time delays of the at least threeGPS antennas 104.
The delay of the signal acquisition time of theGPS antenna 104 is caused by the inconsistency of the start response time of theGPS antenna 104, which is related to factors such as the clock accuracy of the GPS itself, and the inconsistency of the sampling time points of each GPS antenna causes an error in the theoretical attitude data obtained by subsequent calculation, and if the GPS sampling error is not corrected by an algorithm, the error is brought into the calibration of theMEMS gyroscope 101, so that the deviation of theMEMS gyroscope 101 cannot be eliminated. Themain controller 102 corrects the delay error by analyzing and calculating a plurality of groups of continuously collected position data, and avoids influencing the correction of the subsequent error of theMEMS gyroscope 101.
According to the embodiment of the invention, at least 3 GPS antennae are arranged on the sports equipment, and the position data acquired by the GPS antennae are corrected in an auxiliary manner by an RTK (real-time kinematic) method, so that the accuracy is improved. The position data are processed by the GPS processing module and then sent to the main controller, the main controller carries out algorithm correction on time delay of the position data collected by the GPS, then theoretical attitude data of the motion equipment are obtained through calculation, and errors caused by null shift of the MEMS gyroscope are calibrated according to real-time attitude data recorded by the MEMS gyroscope at the same time point, so that the reliability and the accuracy of motion attitude estimation of the navigation system are improved, and the application range of the MEMS gyroscope is expanded.
Example two
Fig. 2 is a flowchart of a calibration method of a micro-electromechanical MEMS gyroscope according to a second embodiment of the present invention, where the calibration method is executed by a calibration apparatus of a micro-electromechanical MEMS gyroscope according to the first embodiment, and the calibration method includes:
s101, collecting position data of the movement equipment at a plurality of time points by at least three GPS antennas, improving accuracy by the aid of RTK method auxiliary correction, and sending the position data to a main controller through a GPS processing module;
s102, the MEMS gyroscope collects real-time attitude data of the motion equipment at a plurality of time points and sends the real-time attitude data to the main controller;
s103, the main controller calculates theoretical attitude data of the motion equipment according to the position data of the motion equipment, and calibrates the MEMS gyroscope according to the theoretical attitude data and the real-time attitude data of the same time point.
Before the main controller calculates theoretical attitude data of the motion device according to the position data of the motion device and calibrates the MEMS gyroscope according to the theoretical attitude data and the real-time attitude data at the same time point, the method further includes:
the master controller corrects the signal acquisition time delays of at least three GPS antennas.
The specific correction principle is as follows:
taking three GPS antennas as an example, the three GPS antennas are respectively arranged on three points A, B and C of the machine body (the three points are not collinear and are not superposed), and the sampling periods of the three GPS antennas are t;
at the moment of starting up, 3GPS antennas 104 start to collect signals, and at this time, it is assumed that themain controller 102 first receives a signal a, and simultaneously, a timer (accurate to 1ms) of themain controller 102 is cleared to zero, and the signals respectively pass through Δ t1And Δ t2The signals of B and C are received after a time, so that the delays of B and C are respectively determined to be Deltat1And Δ t2;
Further assume that in the nth sampling period (n)>3) the acquired coordinate vectors A, B, C are (x) respectively1,y1,z1),(x2,y2,z2),(x3,y3,z3) In the (n-1) th sampling period, the collected coordinate vectors A ', B ' and C ' are respectively (x)1',y1',z1'),(x2',y2',z2'),(x3',y3',z3'at n +1 sampling cycle, the collected coordinate vectors A', B ', C' are respectively (x)1'',y1'',z1''),(x2'',y2'',z2''),(x3'',y3'',z3'');
Since the sampling period t < ═ 0.1S, during this very short time, three points A, B, C on a normally flying aircraft can be considered approximately as uniform linear motion or stationary,
taking point B as an example, the velocity vector of point B is V from the nth-1 st moment to the nth moment2=(x2-x2',y2-y2',z2-z2')/t
And, at n to n +1 times, the velocity vector of point B remains unchanged,
and due to the acquisition delay delta t of the point B1Therefore, after correction, the coordinate vector of the point B at the time n +1 is B1''=B''-V2*△t1=(x2'',y2'',z2'')-(x2-x2',y2-y2',z2-z2')/t*△t1
Similarly, the position coordinates of the point C may be corrected.
The main controller calculates theoretical attitude data of the motion equipment according to the position data of the motion equipment, and calibrates the MEMS gyroscope according to the theoretical attitude data and the real-time attitude data of the same time point, and the method comprises the following steps:
s113, the main controller calculates theoretical attitude data of the motion equipment according to the position data of the motion equipment;
s123, the main controller calculates attitude deviation according to theoretical attitude data and real-time attitude data of the same time point;
and S133, calibrating the MEMS gyroscope by the main controller according to the average value of the attitude deviations of the plurality of time points.
The calibration method of the micro-electromechanical MEMS gyroscope provided by the embodiment of the invention is implemented by adopting the calibration device of the micro-electromechanical MEMS gyroscope in the first embodiment, the method comprises the steps of processing position data acquired by a GPS antenna through a GPS processing module, sending the position data to a main controller to obtain theoretical attitude data of motion equipment through calculation, carrying out attitude deviation calculation on the theoretical attitude data and real-time attitude data acquired by the MEMS gyroscope at the same time through the main controller, and calibrating the MEMS gyroscope according to the average value of the attitude deviations at a plurality of time points. The method effectively corrects the error of the MEMS gyroscope caused by null shift in the motion process, and improves the accuracy and reliability of the measurement of the navigation system of the motion equipment.
EXAMPLE III
A drone navigation system comprising:
an unmanned aerial vehicle and a micro-electromechanical system (MEMS) gyroscope calibration device in the first embodiment;
at least three GPS antennas of the MEMS gyroscope calibration device are positioned on the unmanned aerial vehicle.
The unmanned aerial vehicle navigation system provided by the embodiment of the invention adopts the micro-electromechanical MEMS gyroscope calibration device in the first embodiment, errors caused by null shift of the MEMS gyroscope are accumulated continuously along with time, and are a main source of the unmanned aerial vehicle navigation system errors.
It is to be noted that the foregoing is only illustrative of the preferred embodiments of the present invention and the technical principles employed. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail by the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the present invention, and the scope of the present invention is determined by the scope of the appended claims.