Unmanned aerial vehicle positioning system and positioning method
阅读说明：本技术 一种无人机定位系统和定位方法 (Unmanned aerial vehicle positioning system and positioning method ) 是由 江玲 袁火平 于兴旺 于 2020-06-22 设计创作，主要内容包括：本发明公开了一种无人机定位系统和定位方法,能够在隧道或者洞穴中等卫星信号很差的地方进行定位导航。无人机上携带有无信息的标签,无人机在飞行过程中在相应位置贴上标签,贴标签的同时赋予标签位置信息并将此处标签的位置信息返回给系统以便于后续定位导航。本发明的优点在于：可以隧道或者洞穴中等卫星信号很差的地方实现自动定位导航,保障了人身安全,实现了精准导航。(The invention discloses an unmanned aerial vehicle positioning system and a positioning method, which can perform positioning navigation in places with poor satellite signals, such as tunnels or caves. Carry the label of no information on the unmanned aerial vehicle, unmanned aerial vehicle pastes the label in relevant position at the flight in-process, gives label positional information and returns the positional information of here label for the system so that follow-up location navigation when labelling. The invention has the advantages that: the method can realize automatic positioning navigation in places with poor satellite signals, such as tunnels or caves, ensures personal safety and realizes accurate navigation.)
1. The utility model provides an unmanned aerial vehicle positioning system, includes unmanned aerial vehicle, its characterized in that:
the wireless unit comprises a module with a flight function, a radio frequency read-write module, an edge calculation module, a database, a satellite positioning module, a signal system, an obstacle avoidance module, an image identification module and an automatic electronic tag pasting module;
the automatic electronic tag sticking module can carry and install an electronic tag.
The electronic tag carries unique identification information;
the radio frequency read-write module is used for receiving verification information transmitted by the electronic tag based on UWB technology and transmitting the information to the edge calculation module; the database is used for storing coordinate position information corresponding to the electronic tags;
the edge calculation module is used for searching the position coordinate information of the corresponding electronic tag in the database and calculating the real-time position of the unmanned aerial vehicle;
the satellite positioning module is used for positioning the initial position of the unmanned aerial vehicle and positioning the coordinate position of the electronic tag at the initial moment;
the obstacle avoidance module and the image identification module are used for planning the flight path of the unmanned aerial vehicle and selecting the position of the electronic tag.
2. The radio frequency identification-based unmanned aerial vehicle positioning system of claim 1, wherein the number of the electronic tags is greater than or equal to three, and the signal ranges of at least three electronic tags cover the real-time coordinate position of the unmanned aerial vehicle at any time.
3. Unmanned aerial vehicle positioning method applied to any preceding claim, characterized by comprising the following steps:
(1) by utilizing a satellite positioning technology, fixedly installing three or more electronic tags with known position coordinates manually or by an unmanned aerial vehicle in advance, and acquiring the coordinate position of the unmanned aerial vehicle;
(2) when the unmanned aerial vehicle flies into the signal range of the electronic tag, the magnetic field in the identification area of the radio frequency read-write module enables the electronic tag to generate induction current, and the chip of the electronic tag transmits a signal to the radio frequency read-write module;
(3) after the radio frequency read-write module receives three or more electronic tag signals, the signal intensity, the absolute time difference of signal receiving and sending and the corresponding electronic tag information are input to the edge calculation module;
(4) the edge calculation module accesses a database to obtain coordinate position information of a corresponding electronic tag;
(5) after receiving the electronic tag coordinate position information of the database, the edge calculation module obtains the coordinate position of the unmanned aerial vehicle by using a TDOA (time difference of arrival) positioning method;
(6) judging whether the signal intensity of the electronic tag is attenuated to a threshold value, selecting a proper position by using the obstacle avoidance module and the image identification module, controlling the unmanned aerial vehicle to fly and support, installing a new electronic tag at the current unmanned aerial vehicle position, and recording the identity identification information and the coordinate position information of the electronic tag into a database.
4. The method for locating the unmanned aerial vehicle as claimed in claim 3, wherein the TDOA locating method is implemented by calculating an absolute time difference distance from the radio frequency read-write module to each two electronic tags, then solving an equation set by fitting a least square method, and selecting a solution closest to a last-time position of the unmanned aerial vehicle as a current-time coordinate position of the unmanned aerial vehicle, and the calculating method is as follows:
wherein i and j are electronic tag numbers and i is not equal to j, tiThe time difference from the sending of a signal to the receiving of the ith electronic tag signal is given to the radio frequency read-write module, and c is the speed of light; (x)i，yi，zi) Is the fixed coordinate position of the ith electronic tag.
Technical Field
The invention relates to a positioning system and a positioning method, and belongs to the technical field of unmanned aerial vehicles.
Background
At present, most of home and abroad positioning systems are based on satellite navigation systems, such as a common GPS system, and the adopted positioning technology is usually time difference of arrival (TDOA) positioning technology, which can effectively reduce the influence of obstacles on positioning accuracy. However, in places with weak satellite signals, such as tunnels or caves, the navigation system is not accurately positioned, so several technologies, such as manual detection and positioning, semi-automatic instrument detection and positioning, are often adopted in these special environments, wherein the manual detection only has two to three hours of detection time due to the daily operation of the tunnels, which results in short manual detection lines; semi-automatization's instrument detects owing to just need pre-buried detection sensor when tunnel production, erects special communications facilities simultaneously and just can go on when tunnel operation, and pre-buried sensor survival rate is not very high, and some places are unsafe when installing the sensor moreover, may hurt the people.
The common unmanned aerial vehicle positioning system uses the label for auxiliary positioning, for example, the patent CN106197422B is based on a pasted auxiliary two-dimensional label, and a camera is used for image processing of the label to realize positioning of the unmanned aerial vehicle. Patent CN110632937A is to locate the drone by placing detection tags equidistantly on the oil pipeline. Patent CN110446159A realizes positioning of the drone by combining a label pasted in advance with an auxiliary vision system. The same situation that requires presetting 8 anchor points also exists in patent CN108445914 that uses TDOA location technology to locate the drone. At present, no unmanned aerial vehicle can fly and automatically label in order to assist the system of oneself location at the same time, realizes the unmanned aerial vehicle in the real sense and independently fixes a position the flight under the complex environment.
Disclosure of Invention
Therefore, an object of the present invention is to overcome the above-mentioned drawbacks of the prior art, and to provide a positioning system and a positioning method for an unmanned aerial vehicle, which can perform positioning and navigation in a tunnel or a cave where satellite signals are poor. Carry the electronic tags who does not have information on the unmanned aerial vehicle, unmanned aerial vehicle pastes electronic tags in corresponding position in flight process, gives electronic tags positional information and feeds back this electronic tags's positional information to the system so that follow-up location navigation when pasting electronic tags. This unmanned aerial vehicle positioning system includes unmanned aerial vehicle.
The unmanned aerial vehicle comprises a module with a flight function, a radio frequency read-write module, an edge calculation module, a database, a satellite positioning module, a signal system, an obstacle avoidance module, an image identification module and an automatic electronic tag pasting module.
The automatic electronic tag pasting module can carry and install an electronic tag and can carry and install the electronic tag;
the electronic tag carries unique identification information;
the radio frequency read-write module is used for receiving verification information transmitted by the electronic tag based on UWB technology and transmitting the information to the edge calculation module;
the database is used for storing coordinate position information corresponding to the electronic tags;
the edge calculation module is used for searching the position coordinate information of the corresponding electronic tag in the database and calculating the real-time position of the unmanned aerial vehicle; furthermore, the algorithm contained in the module needs to meet the calculation capability of analyzing multiple paths of signals simultaneously;
the satellite positioning module is used for positioning the initial position of the unmanned aerial vehicle and positioning the coordinate position of the electronic tag at the initial moment;
the obstacle avoidance module and the image identification module are used for planning the flight path of the unmanned aerial vehicle and selecting the position of an electronic tag to be installed.
The number of the electronic tags is more than or equal to three, and the signal range of at least three electronic tags at any moment covers the real-time coordinate position of the unmanned aerial vehicle.
The unmanned aerial vehicle positioning method specifically comprises the following steps:
(1) three or more electronic tags with known position coordinates are fixedly installed manually or in advance by an unmanned aerial vehicle by utilizing a satellite positioning technology so as to obtain the initial coordinate position of the unmanned aerial vehicle;
(2) after the unmanned aerial vehicle flies into the signal range of the electronic tag, the radio frequency read-write module identifies the magnetic field in the area to enable the electronic tag to generate induction current, and the chip of the electronic tag transmits a signal to the radio frequency read-write module;
(3) after the radio frequency read-write module receives three or more electronic tag signals, the signal intensity, the absolute time difference of signal receiving and sending and the corresponding electronic tag information are input to the edge calculation module;
(4) the edge calculation module accesses a database to obtain coordinate position information of a corresponding electronic tag;
(5) after receiving the electronic tag coordinate position information of the database, the edge calculation module obtains the coordinate position of the unmanned aerial vehicle by using a TDOA (time difference of arrival) positioning method;
(6) judging whether the signal intensity of the electronic tag is attenuated to a threshold value, selecting a proper position by using the obstacle avoidance module and the image identification module, controlling the unmanned aerial vehicle to fly and support, installing a new electronic tag at the current unmanned aerial vehicle position, and recording the identity identification information and the coordinate position information of the electronic tag into a database.
The TDOA positioning method comprises the steps of calculating the absolute time difference distance from a radio frequency read-write module to every two electronic tags, then solving an equation set by adopting least square fitting, selecting a solution closest to a last moment position of an unmanned aerial vehicle as a current moment coordinate position of the unmanned aerial vehicle, and adopting the following calculation method:
wherein i and j are electronic tag numbers and i is not equal to j, tiThe time difference from the sending of a signal to the receiving of the ith electronic tag signal is given to the radio frequency read-write module, and c is the speed of light; (x)i，yi，zi) Is the fixed coordinate position of the ith electronic tag.
Has the advantages that:
the invention reduces the positioning precision error by the TDOA positioning technology, simultaneously can select a proper position to be additionally provided with the positioning electronic tag according to the positioning precision requirement and the planning of the flight path, improves the positioning precision, realizes automatic positioning navigation in places with poor satellite signals, such as tunnels or caves, and the like, ensures the personal safety and realizes precise navigation.
Drawings
Fig. 1 is a schematic structural diagram of an unmanned aerial vehicle and an electronic tag according to the present invention; wherein, 1 is the electronic tags who has installed, 2 is unmanned aerial vehicle, 3 are the electronic tags position that need newly install, and the ring is electronic tags signal coverage.
Fig. 2 is a flowchart of a positioning method according to an embodiment of the present invention.
Detailed Description
The technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without inventive effort based on the embodiments of the present invention, are within the scope of the present invention. The specific technical scheme is as follows:
the invention discloses an unmanned aerial vehicle positioning system and a positioning method, which can perform positioning navigation in places with poor satellite signals, such as tunnels or caves. Carry the electronic tags who does not have information on the unmanned aerial vehicle, unmanned aerial vehicle pastes electronic tags at relevant position in flight process, gives electronic tags positional information and returns the positional information of this place electronic tags for the system so that follow-up location navigation when pasting electronic tags. With reference to fig. 1, the drone positioning system includes a drone and an electronic tag.
The unmanned aerial vehicle comprises a module with a flight function, a radio frequency read-write module, an edge calculation module, a database, a satellite positioning module, a signal system, an obstacle avoidance module, an image identification module and an automatic electronic tag pasting module.
The automatic electronic tag pasting module can carry and install an electronic tag and can carry and install the electronic tag;
the electronic tag carries unique identification information;
the radio frequency read-write module is used for receiving verification information transmitted by the electronic tag based on UWB technology and transmitting the information to the edge calculation module;
the database is used for storing coordinate position information corresponding to the electronic tags;
the edge calculation module is used for searching the position coordinate information of the corresponding electronic tag in the database and calculating the real-time position of the unmanned aerial vehicle; furthermore, the algorithm contained in the module needs to meet the calculation capability of analyzing multiple paths of signals simultaneously;
the satellite positioning module is used for positioning the initial position of the unmanned aerial vehicle and positioning the coordinate position of the electronic tag at the initial moment;
the obstacle avoidance module and the image identification module are used for planning the flight path of the unmanned aerial vehicle and selecting the position of an electronic tag to be installed.
The number of the electronic tags is more than or equal to three, and the signal range of at least three electronic tags at any moment covers the real-time coordinate position of the unmanned aerial vehicle.
With reference to fig. 2, the positioning method for the unmanned aerial vehicle specifically includes the following steps:
(1) at the initial moment, three or more than three electronic tags with known position coordinates are fixedly installed in advance in a place near a tunnel or cave where the attenuation of a GPS signal is close to a threshold value in a manual mode by utilizing a satellite positioning technology, the electronic tag information is stored in an unmanned database, and an unmanned aerial vehicle positions the initial coordinate position through the GPS;
(2) the unmanned aerial vehicle takes off and flies towards a target position to enter a tunnel or cave by utilizing the obstacle avoidance module and the image identification module according to a path planning program;
(3) after the unmanned aerial vehicle enters the cave or the tunnel, judging whether the GPS signal intensity is attenuated to a threshold value, if so, performing the step (4); if not, returning to the step (2) until the flight reaches the designated position or the flight task is completed;
(4) the unmanned aerial vehicle radio frequency read-write module transmits UWB signals according to a certain interval time, after flying through the signal range of the electronic tag, the radio frequency read-write module identifies the magnetic field in the area to enable the electronic tag to generate induction current, and the chip of the electronic tag transmits the signals to the radio frequency read-write module;
(5) after the radio frequency read-write module receives three or more electronic tag signals, the signal intensity, the absolute time difference of signal receiving and sending and the corresponding electronic tag information are input to the edge calculation module;
(6) the edge calculation module accesses a database to obtain coordinate position information of a corresponding electronic tag;
(7) after receiving the electronic tag coordinate position information of the database, the edge calculation module rejects unreasonable data, retains at least three electronic tag coordinate position information, and obtains the coordinate position of the unmanned aerial vehicle by using a TDOA (time difference of arrival) positioning method;
(8) judging whether the signal intensity of the electronic tag is attenuated to a threshold value, if so, selecting a proper position within the range of the signal intensity threshold value of the electronic tag by using an obstacle avoidance module and an image recognition module, controlling the unmanned aerial vehicle to fly and support, installing a new electronic tag on the current position of the unmanned aerial vehicle, and recording the identity recognition information and the coordinate position information of the electronic tag into a database; if not, returning to the step (2) until the flight reaches the designated position or the flight task is completed.
The TDOA positioning method comprises the steps of calculating the absolute time difference distance from a radio frequency read-write module to every two electronic tags, then solving an equation set by adopting least square fitting, selecting a solution closest to a last moment position of an unmanned aerial vehicle as a current moment coordinate position of the unmanned aerial vehicle, and adopting the following calculation method:
wherein i and j are electronic tag numbers and i is not equal to j, tiThe time difference from the sending of a signal to the receiving of the ith electronic tag signal is given to the radio frequency read-write module, and c is the speed of light; (x)i，yi，zi) Is the fixed coordinate position of the ith electronic tag.
According to the invention, the unmanned aerial vehicle can be attached with the electronic tag in the flying process, so that automatic positioning and navigation can be realized in places with poor satellite signals, such as tunnels or caves, the personal safety is ensured, and the efficiency is improved. In particular, to ensure the positioning accuracy, the number of electronic tags in the signal range is usually required to be much greater than three.
The present invention is not limited to the embodiments described above, and it will be apparent to a person skilled in the art that any modifications or variations to the embodiments of the present invention described above are possible without departing from the scope of protection of the embodiments of the present invention and the appended claims, which are given by way of illustration only and are not intended to limit the invention in any way.