CN1888930A - Adaptive self-monitoring device and method based on indoor positioning - Google Patents

Abstract

One orientation ministrant method and terminal of the GPS technology is particular a self-suit and self-determination inspection equipment and method based indoor orientation using for goal GPS and inspection technology field. It relates to communicate module, sensor, CPU, interface, crystal, electrical source, and so on. The control inspection module and electrical source manage module connect with each other by interface signal line. The whole terminal connects to the center control port through CDMA1X chain line to solve the technology problem of the adjustment of self-suit alarm door limit and system error worked by the CDMA+ GPSONE indoor orientation. This uses to goods inspection system and self-suit initialize to the longitude, latitude and alarm door limit by the self-determination estimation pattern to the least probability to false alarm and leak alarm, and solves the system error worked by the CDMA+ GPSONE indoor orientation.

Description

Adaptive self-monitoring device and method based on indoor positioning

Technical field

The present invention relates to a kind of GPS (Global Positiong System) Global Positioning System (GPS) technology; Specifically, design belongs to the adaptive self-monitoring device and the method based on indoor positioning in moving target global location and monitoring technique field based on the method and the terminal thereof of the positioning service of GPSOne, cdma base station, Internet, CDMA 1X.

Background technology

The GPSOne location technology combines the advantage of GPS location and network assistance location, has solved the not high and excessive difficult problem of power consumption of sensitivity of GPS indoor positioning.In the outdoor GPS locator meams of taking, bearing accuracy can compare favourably with traditional GPS locating terminal, indoor owing to be subjected to the difference of network signal, take the locator meams of advanced forward link range of triangle location AFLT preferably the time at signal, bearing accuracy can reach 5-50 rice, when advanced forward link range of triangle location AFLT can not realize locating, then automatically switch to the locator meams of cellular cell location cell ID.Because the influence that cellular cell location cell ID is distributed by cdma base station is bigger, bearing accuracy may reach 500-1000 rice.

In the locating and monitoring field, present common way is to carry out location positioning by monitor terminal, then with reporting position Surveillance center, carries out position calculation by Surveillance center, realizes the monitoring of equipment.Because indoor positioning is subjected to effect of signals bigger, there is bigger systematic error in bearing accuracy, and these information are uncertain for Surveillance center, so have bigger false-alarm and false dismissal situation in monitoring; And if position data at every turn and report, needing a large amount of Internet resources of waste, use cost is too high, therefore by autonomous positioning and judge being necessary very much that SOT state of termination shows.

Summary of the invention

In order to overcome above-mentioned weak point, fundamental purpose of the present invention aims to provide a kind of adaptive self-monitoring device and method based on indoor positioning, the present invention is by the detailed explanation for false-alarm, false dismissal, theory has been proved this a pair of conflicting technical parameter, and by analysis for the mathematical distribution of locator data, the join probability opinion this to parameter regulation of contradiction to optimal ratio; And by adaptive algorithm, constantly the real-time update data parameters has well solved because the systematic error that the CDMA+GPSONE indoor positioning causes; The method and the thinking of this analysis have ubiquity, also are suitable for the adaptive self-monitoring device and the method based on indoor positioning of analyses such as other positioning error probability.

The technical problem to be solved in the present invention is: solve charging circuit hardware design problem; House dog switch controlling Design problem when will the solution state switching; Solve mathematical reasoning and demonstration problem that false-alarm, false dismissal probability are applied to positioning system; Solve adaptive reference standard longitude and latitude adjustment technology problem; Solve adjustment of adaptive alarm thresholding and because the relevant technologies problems such as systematic error that the CDMA+GPSONE indoor positioning causes.

The technical solution adopted for the present invention to solve the technical problems is: this device is made up of parts such as communication module, memory module, sensor, switch, CPU, interface, crystal oscillator and power supplys, it also comprises: control monitoring modular and power management module, interconnect by interface signal line therebetween, whole terminal interconnects by CDMA1X link and center control port, wherein:

The control monitoring modular is made up of memory module, RS232 serial ports, control module CPU, communication module, crystal oscillator and observation circuit etc., the input/output port of memory module and RS232 serial ports is connected with the I/O mouth of control module CPU respectively, the input/output port of control module CPU is connected with the I/O mouth of communication module respectively, the output port of crystal oscillator and observation circuit is connected with the input port of control module CPU respectively, and the output port of communication module is connected with the input port of antenna;

Power management module is made up of charging circuit, battery and power supply etc., and the input port of charging circuit is connected with external direct-flow input signal line, and the output port of charging circuit is connected with the input port of battery and power supply respectively.

The input/output port of the control module CPU of described adaptive self-monitoring device based on indoor positioning or be connected with the I/O mouth of watchdog chip, the output terminal of control module CPU is connected with the input end of a house dog on-off circuit of watchdog chip after via switch, another output terminal of control module CPU is connected with hello dog input pin via the feeding-dog signal line, and the output pin that resets of watchdog chip is connected with the resetting pin of control module CPU.

The control module CPU pin 1 of the house dog on-off circuit of described adaptive self-monitoring device based on indoor positioning interconnects with the pin 7 of watchdog chip; The pin 6 of one tunnel and watchdog chip of control module CPU pin 2 interconnects, and another road is via resistance R 213 back ground connection; Control module CPU pin 3 is connected with optocoupler pipe pin 1 via resistance R 210 backs; Optocoupler pipe pin 2 ground connection, optocoupler pipe pin 3 is connected with the pin 8 of watchdog chip, and optocoupler pipe pin 4 is connected with the pin 1 of watchdog chip via resistance R 211 backs; Pin 3 ground connection of watchdog chip; The pin 2 of watchdog chip connects power supply.

The power supply of described adaptive self-monitoring device based on indoor positioning is connected with the port of power module, battery, digital control circuit and communication module respectively, wherein:

Direct current input 12V1A signal divides two-way to export, and one the tunnel via being connected with an input end of digital control circuit behind power module 6V output A and the power module output 3.3V; Another road is connected with the input end of power module output 3.3V via behind power module 6V output B and the battery circuit; Another output terminal of power module 6V output A is connected with an input end of communication module after exporting 4.2V via power module.

The pin 1 of the battery circuit U101 module of described adaptive self-monitoring device based on indoor positioning is connected with the DC voltage input signal cable;

Pin 5 is connected with the charging control switch signal wire;

A road of pin 3 is connected another road ground connection via resistance R 111 back with the charging control switch signal wire;

A road of pin 2 has four tunnel output signals after inductance L 101, first via feedback is connected with pin 4 via resistance R 104, the second the tunnel is connected with the output port of battery voltage detection via schottky diode D104 and resistance R 105 backs, Third Road is via capacitor C 106 back ground connection, and the four the tunnel via capacitor C 105 back ground connection; Another road of pin 2 via schottky diode D103 after ground connection;

Pin 4 a road via resistance R 103 back ground connection, there are two tunnel output signals on another road after via resistance R 104, the first via is divided into two-way again after via schottky diode D104 and resistance R 105, one the tunnel via being connected with the cell voltage output signal line behind the schottky diode D105, another road via switch and battery after ground connection, the extension line between switch and battery is the battery voltage detection signal wire; The second the tunnel via capacitor C 105 back ground connection.

A kind of adaptive self method for supervising based on indoor positioning, this method arrive optimal ratio by the analysis join probability opinion of locator data mathematical distribution with false-alarm, this parameter regulation to contradiction of false dismissal probability; And by adaptive algorithm, constantly the real-time update data parameters reaches the systematic error that the solution indoor positioning causes; This method comprises: the initial longitude and latitude setting of monitored device; Initial alarm threshold setting; Current mean bias monitoring; Current positioning error monitoring and adaptively changing alarm threshold; Its concrete job step is:

Step 1. initialization

At first carry out the system module initialization, obtain locator data, get average and this locator data is write terminal inner flash memory FLASH after locating 30 times continuously, be set to the initialization longitude and latitude of terminal by CDMA/GPSONE module serial ports output;

Step 2. locating and monitoring

The initialized output signal of system module is divided into two-way, and one the tunnel for entering comparison module, and positioning result is compared with alarm threshold; Another road enters locating module, monitor terminal was located once according to client's the every fixed interval of the demand time, the data that obtain after at every turn locating are kept among the flash memory FLASH, and calculate these data with the distance between the initialization longitude and latitude by 2 range formulas;

Step 3. relatively

The output signal of comparison module is divided into two-way, and one the tunnel reports center module for entering, and after calculated distance surpasses alarm threshold, thinks that then monitored article have moved certain scope and reported the center;

Another road enters the alarm threshold module, when calculated distance does not exceed alarm threshold, thinks that then monitored article are not for moving, obtain last workaday positioning result, self-adaptation change alarm threshold, then terminal standby dormancy, if there is not dispatch from foreign news agency, real-time clock RTC then is set regularly, close house dog, enter sleep pattern, after real-time clock RTC look-at-me, enter real-time clock RTC and interrupt waking up again, open house dog, enter locating module again, up to locate next time;

If dispatch from foreign news agency is arranged, real-time clock RTC then is set regularly, after real-time clock RTC look-at-me, enter locating module more again;

Step 4. moves and reports the center

Movable signal enters and reports the output signal of center module to be divided into two-way, and one the tunnel is no dispatch from foreign news agency, real-time clock RTC then is set regularly, close house dog, enter sleep pattern, in real-time clock RTC, have no progeny again, enter real-time clock RTC and interrupt waking up, open house dog, enter locating module again;

If dispatch from foreign news agency is arranged, real-time clock RTC then is set regularly, after real-time clock RTC look-at-me, enter locating module more again;

Step 5. is provided with the self-adaptive initial longitude and latitude

To be every day a time unit, carry out the adjustment of initialization longitude and latitude;

If alarm condition did not take place the same day, the longitude and latitude data that will preserve the same day are added up, and calculate the mean value E of this day N positioning result, this E is replaced former E, promptly calculate the initialization longitude and latitude make new advances and replace originally,, reach the adjustment of self-adaptive initial longitude and latitude to upgrade this every day;

Step 6. is provided with the adaptive alarm thresholding

To be every day a unit, carry out the adjustment of adaptive alarm thresholding;

If alarm condition did not take place the same day, the longitude and latitude data that will preserve the same day are added up, and calculate this day N positioning result standard deviation sigma, this standard deviation sigma is replaced former σ, the alarm threshold value that calculating makes new advances is also replaced originally, to upgrade this, reaches the adjustment of adaptive alarm thresholding every day.

The alarm threshold of described adaptive self method for supervising based on indoor positioning is for by calculating the numerical value that obtains corresponding alarm threshold, and its concrete calculation procedure is:

If step 1. normal distribution

O is the initial point of two-dimensional coordinate with the terminal permanent datum, supposes that the terminal positioning result belongs to normal distribution with respect to the coordinate X and the Y of initial point, and both are independent, and variance is respectively σ _x, σ _yThen its joint probability density function is:

$f(x,y)=\frac{1}{2\mathrm{\π}{\mathrm{\σ}}_x{\mathrm{\σ}}_y}{e}^{-\frac{x^2{{\mathrm{\σ}}_y}^2+y^2{{\mathrm{\σ}}_x}^2}{2{{\mathrm{\σ}}^2}_x{{\mathrm{\σ}}^2}_y}}$

Step 2. is if positioning result exceeds radius

If positioning result exceeds the circle that radius is R, then false-alarm has taken place in expression, and its probability calculation formula is:

Wherein: establish σ _xThe standard deviation of expression longitude, σ _yThe standard deviation of expression latitude is got σ _x=200, σ _y=120, R is an alarm threshold;

The concrete calculation procedure of the false dismissal probability of described adaptive self method for supervising based on indoor positioning is:

If step 1. normal distribution

Represent that with an O average of two-dimentional normal distribution, left side radius are the circle expression false dismissal scope of R, in case test point drops on this zone, just false dismissal has taken place in expression;

Step 2. computing formula

The computing formula of its probability is as follows:

$\mathrm{func}\left(d\right):=\left[{\∫}_{-R}^R{\∫}_{-\sqrt{R^2-x^2}}^{\sqrt{R^2-x^2}}\frac{{1-e}^{\left[\frac{{{\mathrm{\σ}}_x}^2{y}^2+{(x-d)}^2-{{\mathrm{\σ}}_y}^2}{-2-{{\mathrm{\σ}}_x}^2-{{\mathrm{\σ}}_y}^2}\right]}}{2-\mathrm{\π}{-\mathrm{\σ}}_x{-\mathrm{\σ}}_y}\mathrm{dydx}\right]$

Wherein, R represents alarm threshold, and d represents measuring distance, σ _xExpression longitude standard deviation, σ _yExpression latitude standard deviation.

The invention has the beneficial effects as follows: this product is applied in the goods monitoring system, voltage stabilizing trickle charging circuit pattern wherein and sleep state house dog switch mode can greatly reduce the power consumption to the power requirement of system power supply and saving total system, and product can be worked long hours.Inner by being new pioneering invention for the autonomous judgment model of false-alarm false dismissal minimum probability and self-adaptive initial longitude and latitude and alarm threshold, the effect of the GPSONE indoor positioning data processing by the later stage has been obtained improving greatly, make by after the GPSONE indoor positioning, autonomous monitoring, the judgement of whether moving a segment distance becomes possibility, well solved because the systematic error that the CDMA+GPSONE indoor positioning causes, the method and the thinking of this analysis have ubiquity, also are suitable for analysis situations such as other positioning error probability; The effect of this method is very obvious, will bring the significantly raising of location technology stability, accuracy.

Description of drawings

The present invention is further described below in conjunction with description of drawings and embodiment.

Accompanying drawing 1 is one-piece construction block scheme of the present invention;

Accompanying drawing 2 is power module block scheme of the present invention;

Accompanying drawing 3 is battery charger schematic diagram of the present invention;

Accompanying drawing 4 is constant voltage trickle charging circuit schematic diagram of the present invention;

Accompanying drawing 5 is house dog of the present invention and reset circuit block scheme;

Accompanying drawing 6 is house dog switch designs circuit theory diagrams of the present invention;

Accompanying drawing 7 is an adaptive self method for supervising program flow diagram of the present invention;

Accompanying drawing 8 calculates synoptic diagram for false-alarm probability of the present invention;

Accompanying drawing 9 calculates synoptic diagram for false dismissal probability of the present invention;

The drawing reference numeral explanation:

The 1-memory module;

The 2-RS232 serial ports;

3-control module CPU 301-house dog switch;

The 4-communication module; The 302-output pin that resets;

The 5-crystal oscillator; 303-feeds the dog input pin;

The 6-observation circuit; 304-optocoupler pipe;

The 7-charging circuit; The input of 701-DC voltage;

The 8-battery; The 702-charging control switch;

The 9-power supply; The 703-U101 module;

10-controls monitoring modular; The output of 704-cell voltage;

The 11-antenna; The 705-battery voltage detection;

The 12-switch;

The 13-resetting pin;

14-feeds dog;

The 20-power management; 101-direct current input 12V1A

The 30-watchdog chip; 102-power module 6V exports A;

The 40-initialization; 103-power module 6V exports B;

41-relatively; 104-power module output 3.3V;

The 42-alarm threshold; 105-power module output 4.2V;

The 43-sleep pattern; The 106-digital control circuit;

44-interrupts waking up;

45-is provided with RTC regularly;

The 46-location;

47-reports the center;

Embodiment:

See also shown in the accompanying drawing 1,2,3,4,5,6,7,8,9, the present invention is made up of parts such as communication module, memory module, sensor, switch, CPU, interface, crystal oscillator and power supplys, it also comprises: control monitoring modular (10) and power management (20) module, interconnect by interface signal line therebetween, whole terminal interconnects by CDMA1X link and center control port, wherein:

Control monitoring modular (10) is by memory module (1), RS232 serial ports (2), control module CPU (3), communication module (4), crystal oscillator (5) and observation circuit compositions such as (6), the input/output port of memory module (1) and RS232 serial ports (2) is connected with the I/O mouth of control module CPU (3) respectively, the input/output port of control module CPU (3) is connected with the I/O mouth of communication module (4) respectively, the output port of crystal oscillator (5) and observation circuit (6) is connected with the input port of control module CPU (3) respectively, and the output port of communication module (4) is connected with the input port of antenna (11);

Power management (20) module is made up of charging circuit (7), battery (8) and power supply (9) etc., the input port of charging circuit (7) is connected with external direct-flow input signal line, and the output port of charging circuit (7) is connected with the input port of battery (8) with power supply (9) respectively.

See also shown in the accompanying drawing 5, the input/output port of the control module CPU (3) of described adaptive self-monitoring device based on indoor positioning or be connected with the I/O mouth of watchdog chip (30), the output terminal of control module CPU (3) is connected with the input end of house dog switch (a 301) circuit of watchdog chip (30) via switch (12) back, another output terminal of control module CPU (3) is connected with hello dog input pin (303) via feeding dog (14) signal wire, and the output pin that resets (302) of watchdog chip (30) is connected with the resetting pin (13) of control module CPU (3).

See also shown in the accompanying drawing 6, control module CPU (3) pin 1 of house dog switch (301) circuit of described adaptive self-monitoring device based on indoor positioning interconnects with the pin 7 of watchdog chip (30); The pin 6 of one tunnel and watchdog chip (30) of control module CPU (3) pin 2 interconnects, and another road is via resistance R 213 back ground connection; Control module CPU (3) pin 3 is connected with optocoupler pipe (304) pin 1 via resistance R 210 backs; Optocoupler pipe (304) pin 2 ground connection, optocoupler pipe (304) pin 3 is connected with the pin 8 of watchdog chip (30), and optocoupler pipe (304) pin 4 is connected with the pin 1 of watchdog chip (30) via resistance R 211 backs; Pin 3 ground connection of watchdog chip (30); The pin 2 of watchdog chip (30) connects power supply.

See also shown in the accompanying drawing 2, the power supply of described adaptive self-monitoring device based on indoor positioning is connected with power module, battery (8), digital control circuit (106) and the port of communication module (4) respectively, wherein:

Direct current input 12V1A (101) signal divides two-way output, and one the tunnel exports 3.3V (104) back via power module 6V output A (102) with power module is connected with an input end of digital control circuit (106); Another road is connected with a input end that power module is exported 3.3V (104) after via power module 6V output B (103) and battery (8) circuit; Another output terminal of power module 6V output A (102) is exported 4.2V (105) back via power module and is connected with an input end of communication module (4).

See also shown in the accompanying drawing 3, the pin 1 of battery (8) circuit U 101 modules (703) of described adaptive self-monitoring device based on indoor positioning is connected with DC voltage input (701) signal wire;

Pin 5 is connected with charging control switch (702) signal wire;

A road of pin 3 is connected another road ground connection via resistance R 111 back with charging control switch (702) signal wire;

A road of pin 2 has four tunnel output signals after inductance L 101, first via feedback is connected with pin 4 via resistance R 104, the second the tunnel is connected with the output port of battery voltage detection (705) via schottky diode D104 and resistance R 105 backs, Third Road is via capacitor C 106 back ground connection, and the four the tunnel via capacitor C 105 back ground connection; Another road of pin 2 via schottky diode D103 after ground connection;

Pin 4 a road via resistance R 103 back ground connection, there are two tunnel output signals on another road after via resistance R 104, the first via is divided into two-way again after via schottky diode D104 and resistance R 105, one the tunnel via being connected with cell voltage output (704) signal wire behind the schottky diode D105, another road is via switch and battery (8) back ground connection, and the extension line between switch and battery (8) is battery voltage detection (a 705) signal wire; The second the tunnel via capacitor C 105 back ground connection.

See also shown in the accompanying drawing 7, a kind of adaptive self method for supervising based on indoor positioning is characterized in that: this method arrives optimal ratio by the analysis join probability opinion of locator data mathematical distribution with false-alarm, this parameter regulation to contradiction of false dismissal probability; And by adaptive algorithm, constantly the real-time update data parameters reaches the systematic error that the solution indoor positioning causes; This method comprises: the initial longitude and latitude setting of monitored device; Initial alarm threshold setting; Current mean bias monitoring; Current positioning error monitoring and adaptively changing alarm threshold; Its concrete job step is:

Step 1. initialization (40)

At first carry out system module initialization (40), obtain locator data, get average and this locator data is write terminal inner flash memory FLASH after locating 30 times continuously, be set to the initialization longitude and latitude of terminal by CDMA/GPSONE module serial ports output;

Step 2. locating and monitoring

The output signal of system module initialization (40) is divided into two-way, and one the tunnel for entering comparison (41) module, and positioning result is compared with alarm threshold; Another road enters location (46) module, monitor terminal was located once according to client's the every fixed interval of the demand time, the data that obtain after at every turn locating are kept among the flash memory FLASH, and calculate these data with the distance between the initialization longitude and latitude by 2 range formulas;

Step 3. is (41) relatively

Relatively the output signal of (41) module is divided into two-way, and one the tunnel reports center (47) module for entering, when calculated distance above behind the alarm threshold, think that then monitored article have moved certain scope and reported center (47);

Another road enters alarm threshold (42) module, when calculated distance does not exceed alarm threshold, think that then monitored article are not for moving, obtain last workaday positioning result, self-adaptation change alarm threshold (42), then terminal standby dormancy, if there is not dispatch from foreign news agency, real-time clock RTC then is set regularly, close house dog, enter sleep pattern (43), after real-time clock RTC look-at-me, enter real-time clock RTC and interrupt waking (44) up again, open house dog, enter location (46) module again, up to locate next time;

If dispatch from foreign news agency is arranged, real-time clock RTC regularly (45) then is set, after real-time clock RTC look-at-me, enter location (46) module more again;

Step 4. moves and reports center (47)

Movable signal enters and reports the output signal of center (47) module to be divided into two-way, one the tunnel is no dispatch from foreign news agency, real-time clock RTC then is set regularly, close house dog, enter sleep pattern (43), in real-time clock RTC, have no progeny again, enter real-time clock RTC and interrupt waking up (44), open house dog, enter location (46) module again;

If dispatch from foreign news agency is arranged, real-time clock RTC regularly (45) then is set, after real-time clock RTC look-at-me, enter location (46) module more again;

Step 5. is provided with the self-adaptive initial longitude and latitude

To be every day a time unit, carry out the adjustment of initialization longitude and latitude;

If alarm condition did not take place the same day, the longitude and latitude data that will preserve the same day are added up, and calculate the mean value E of this day N positioning result, this E is replaced former E, promptly calculate the initialization longitude and latitude make new advances and replace originally,, reach the adjustment of self-adaptive initial longitude and latitude to upgrade this every day;

Step 6. is provided with the adaptive alarm thresholding

To be every day a unit, carry out the adjustment of adaptive alarm thresholding;

If alarm condition did not take place the same day, the longitude and latitude data that will preserve the same day are added up, and calculate this day N positioning result standard deviation sigma, this standard deviation sigma is replaced former σ, the alarm threshold value that calculating makes new advances is also replaced originally, to upgrade this, reaches the adjustment of adaptive alarm thresholding every day.

See also shown in the accompanying drawing 8, the alarm threshold of described adaptive self method for supervising based on indoor positioning is for by calculating the numerical value that obtains corresponding alarm threshold, and its concrete calculation procedure is:

If step 1. normal distribution

O is the initial point of two-dimensional coordinate with the terminal permanent datum, supposes that the terminal positioning result belongs to normal distribution with respect to the coordinate X and the Y of initial point, and both are independent, and variance is respectively σ _x, σ _yThen its joint probability density function is:

$f(x,y)=\frac{1}{2\mathrm{\&pi;}{\mathrm{\&sigma;}}_x{\mathrm{\&sigma;}}_y}{e}^{\frac{x^2{{\mathrm{\&sigma;}}_{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="A20061002901600321.png,A20061002901600381.png"\; state="\{\{state\}\}">y</figure-callout>}}}^2+{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="A20061002901600321.png,A20061002901600381.png"\; state="\{\{state\}\}">y</figure-callout>}}^2{{\mathrm{\&sigma;}}_x}^2}{2{\mathrm{\&sigma;}}^2{{\mathrm{\&sigma;}}^2}_y}}$

Step 2. is if positioning result exceeds radius

If positioning result exceeds the circle that radius is R, then false-alarm has taken place in expression, and its probability calculation formula is:

Wherein: establish σ _xThe standard deviation of expression longitude, σ _yThe standard deviation of expression latitude is got σ _x=200, σ _y=120, R is an alarm threshold;

See also shown in the accompanying drawing 9, described adaptive self method for supervising based on indoor positioning is characterized in that: the concrete calculation procedure of described false dismissal probability is:

If step 1. normal distribution

Represent that with an O average of two-dimentional normal distribution, left side radius are the circle expression false dismissal scope of R, in case test point drops on this zone, just false dismissal has taken place in expression;

Step 2. computing formula

The computing formula of its probability is as follows:

$\mathrm{fu}\left(d\right):=\left[{\&Integral;}_{-R}^R{\&Integral;}_{-\sqrt{R^2-x^2}}^{\sqrt{R^2-x^2}}\frac{{1\&CenterDot;e}^{\left[\frac{{{\mathrm{\&sigma;}}_x}^2{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="A20061002901600321.png,A20061002901600381.png"\; state="\{\{state\}\}">y</figure-callout>}}^2+{(x-d)}^2\&CenterDot;{{\mathrm{\&sigma;}}_y}^2}{-2\&CenterDot;{{\mathrm{\&sigma;}}_x}^2\&CenterDot;{{\mathrm{\&sigma;}}_y}^2}\right]}}{2\&CenterDot;\mathrm{\&pi;}{\&CenterDot;\mathrm{\&sigma;}}_x{\&CenterDot;\mathrm{\&sigma;}}_y}\mathrm{dydx}\right]$

Wherein, R represents alarm threshold, and d represents measuring distance, σ _xExpression longitude standard deviation, σ _yExpression latitude standard deviation.

Hardware system of the present invention comprises:

Monitor terminal mainly is made up of embedded type CPU, storer, cdma communication and locating module, power management module, interface module and monitoring and sensing module.Whole terminal is finished and has been judged whether that independently there is function in dispatch from foreign news agency, if any then entering the DC operation state, to the internal cell charging, connects by the concentricity maintenance of CDMA1X link simultaneously, by the center control terminal; Then do not enter sleep state as having, and wake up automatically, position judgement every the regular hour.Whether locator value and the initialization longitude and latitude spacing judged surmount alarm threshold, then do not enter sleep state once more as having, if any then connecting the center at once and reporting to the police.

Of the present invention discharge and recharge the design comprise:

Because battery capacity is bigger, can need if use power management chip to charge

Will more powerful input power supply and work long hours and to influence battery life, therefore use U101 LM2596 chip by feedback precision resistance R103 and the output of R104 regulation voltage, determine whether that by adjusting R111 resistance and CPU I/O mouth pin needing to turn-off this charging chip (opens charging management chip all the time as welding 0 Ohmage; As not welding resistance, then think and control this charging chip) by CPU, D103 is that 1N5822 schottky diode, L101 are that power inductance, C105 are that alminium electrolytic condenser, C106 are chip ceramic capacitor, and these 4 devices design for the noise that reduces charging voltage output.Constant voltage is output as 6.33V, and behind D104 1N5822 schottky diode, according to the family curve of this diode, charging current is about 0.3V by the voltage drop of this diode.Therefore voltage is 6.03V before the power resistor of 1 ohm of 2W of R105.Because designing and calculating 4 joint Ni-MH battery ceiling voltages are about 6V, therefore the Ni-MH battery original state is about 1 * 4V, can get charging current according to circuit formula (internal resistance of cell is ignored) this moment and be (6.03-4)/1A ≈ 2A, rising along with voltage after the battery charge, charging current will constantly reduce, reach until battery and to be about about 6V, charging current is less than 50mA.The design of rear end D105 1N5822 schottky diode is in order to prevent that the back terminal voltage from causing that electric current is counter irritates when the DC operation greater than preceding terminal voltage.When total system did not have dispatch from foreign news agency, charging voltage became 0, and cell voltage is not greater than back-end circuit voltage (rear end has under the dispatch from foreign news agency situation, and initial voltage is 0) at this moment, and battery is then powered to the back-end by D105 1N5822 schottky diode.Thereby reached the purpose that autonomous switching enters battery operated state.

House dog of the present invention and reset circuit design content comprise:

When terminal detects no direct supply and uses internal cell when work, can enter sleep state.This state is a low power consumpting state, need close and feed the dog program, because house dog does not have feeding-dog signal can allow CPU restart, therefore need close watchdog module earlier before entering sleep state.Specific design is as follows:

SWDOG is the last I/O mouth of CPU, is used for controlling switch/MR of house dog.When SWDOG was high level, U203 was that optocoupler TLP opens, at this moment/MR and/the WDO conducting, the dog that opens the door has just been opened, if system's program fleet, the WDI pin does not have the level saltus step.The chip U200 that resets is that MAX706N will give cpu reset by the RST pin.When terminal need enter sleep state, the SWDOG pin transferred low level to, and this moment, the U203 optocoupler was closed ,/MR and/WDO disconnects, this moment, house dog was just closed.After terminal entered sleep state, the WDI pin did not have the level saltus step, and U200 just can not cause to CPU and reset.

The CDMA of the present invention location and the design of communicating by letter:

CDMA/GPSONE positioning and communicating module connects by the UART mouth with CPU, finishes the transmitting-receiving between the data.

On the hardware platform of charging and complete function such as power saving, the adaptive algorithm by the advanced person with finish the autonomous positioning monitoring function.

Correlation machine of the present invention moves the notion of false-alarm false dismissal:

1) machine moves

Machine moves and refers to, and machine has departed from the normal position.Machine is installed on certain position, if certain finds machine not on this position in detecting, monitor terminal will send the warning message that machine moves so.

2) false-alarm

If positioning performance is fine, there is not positioning error, so, in theory, if machine is in certain position always, monitor terminal should not reported the machine mobile status.But in fact, even machine is on certain position always, because positioning error, the locator data that monitor terminal obtains also might depart from the normal position scope, and this situation is called false-alarm (wrong report).The size of mistake alarm probability depends on system accuracy and these two parameters of alarm threshold.

3) false dismissal

Equally, if there is not positioning error, in theory, machine is even be moved one meter, and terminal also can be sent machine mobile alarm information.But in fact, because positioning error is bigger, even machine has been moved a segment distance, monitor terminal also might can't detect, and this situation is called false dismissal (failing to report).The size of false dismissal probability depends on these three parameters of system accuracy, alarm threshold and displacement.After having set alarm threshold, terminal has moved a segment distance, but because positioning result does not exceed the alarm threshold scope, but physical end has shifted out the distance of regulation, and then this situation just is judged to false dismissal.False dismissal probability and mistake alarm probability are the parameters of a pair of contradiction.Reduce the mistake alarm probability, must increase alarm threshold; Increase alarm threshold, increased false dismissal probability again.

Determining of alarm threshold of the present invention:

Move judgement in order to carry out machine, except obtaining initial longitude and latitude (reference point coordinate), also must determine alarm threshold.According to the positioning performance of reality test, under different false-alarm probabilities, can be by calculating the numerical value that obtains corresponding alarm threshold.

O is the initial point of two-dimensional coordinate with the terminal permanent datum, supposes that the terminal positioning result belongs to normal distribution with respect to the coordinate X and the Y of initial point, and both are independent, and variance is respectively σ _x, σ _yIts joint probability density function is:

$f(x,y)=\frac{1}{2\mathrm{\&pi;}{\mathrm{\&sigma;}}_x{\mathrm{\&sigma;}}_y}{e}^{-\frac{x^2{{\mathrm{\&sigma;}}_{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="A20061002901600321.png,A20061002901600381.png"\; state="\{\{state\}\}">y</figure-callout>}}}^2+{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="A20061002901600321.png,A20061002901600381.png"\; state="\{\{state\}\}">y</figure-callout>}}^2{{\mathrm{\&sigma;}}_x}^2}{2{{\mathrm{\&sigma;}}^2}_x{{\mathrm{\&sigma;}}^2}_y}}$

Referring to Fig. 8, if positioning result exceeds the circle that radius is R (R is an alarm threshold), just false-alarm has taken place in expression, and its probability calculation formula is:

Wherein, establish σ _xThe standard deviation of expression longitude, σ _yThe standard deviation of expression latitude.Get σ _x=200, σ _y=120

The standard deviation of longitude and latitude (rice)	σ x＝200，σ y＝120
						Alarm threshold (rice)	100	200	300	400	500
False-alarm probability	81.4％	45.4％	18.7％	6.1％	1.6％

By icon as seen, along with the increasing of alarm threshold, false-alarm probability constantly reduces.If the false-alarm probability that allows is below 2%, chooses suitable alarm threshold so and should be set to 500 meters.

Pay special attention to: the numerical value of above-mentioned false-alarm probability is based on basic inference and obtains, only as the reference of practical application.Consider following problem in practice possibly:

1, the aforementioned calculation result supposes that the longitude of positioning result, latitude numerical value all belong to normal distribution, and both are independent; This is that a kind of of actual conditions is similar to;

2, the aforementioned calculation result is based on that measured data statistical value in the Galileo company obtains, and other local numerical value may be different therewith, and therefore surveying probability may be variant with The above results;

3, The above results is based on and obtains under the situation of desirable initialization longitude and latitude, can not obtain desirable initialization longitude and latitude numerical value fully in the reality, and therefore surveying probability may be variant slightly with The above results

False dismissal probability of the present invention is calculated:

The performance of measurement system except considering false-alarm probability, also must be considered false dismissal probability.

Under current positioning performance condition, given comparison threshold, the false dismissal probability difference under different distances.It can obtain by calculating, and computation process is as follows.

Referring to Fig. 2, some O represents the average of two-dimentional normal distribution, and the left side radius is the circle of R

Expression false dismissal scope.In case test point drops on this zone, just false dismissal has taken place in expression, and the computing formula of its probability is as follows:

$\mathrm{fu}\left(d\right):=\left[{\&Integral;}_{-R}^R{\&Integral;}_{-\sqrt{R^2-x^2}}^{\sqrt{R^2-x^2}}\frac{{1\&CenterDot;e}^{\left[\frac{{{\mathrm{\&sigma;}}_x}^2{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="A20061002901600321.png,A20061002901600381.png"\; state="\{\{state\}\}">y</figure-callout>}}^2+{(x-d)}^2-{{\mathrm{\&sigma;}}_y}^2}{-2-{{\mathrm{\&sigma;}}_x}^2-{{\mathrm{\&sigma;}}_y}^2}\right]}}{2-\mathrm{\&pi;}{-\mathrm{\&sigma;}}_x{-\mathrm{\&sigma;}}_y}\mathrm{dydx}\right]$

Wherein, R represents alarm threshold, and d represents measuring distance, σ _xExpression longitude standard deviation, σ _yExpression latitude standard deviation.

Calculate the false dismissal probability of different measuring distances under given alarm threshold condition, the result is as follows:

The standard deviation of longitude and latitude (rice)	σ x＝200，σ y=120 (Galileo measured results)
						Alarm threshold R (rice)	500
Measuring distance d (rice)	100	200	300	400	500
						False dismissal probability P	16.5％	11.6％	6.5％	2.8％	0.99％

By chart as can be seen, along with continuing to increase of measuring distance, false dismissal probability is constantly dwindled.Can judge that when displacement was 500 meters, the probability of false dismissal was less than 1%.This terminal of explanation of reporting to the police surely to physical location to have exceeded 500 meters of standard longitudes and latitudes far away.

Pay special attention to: the numerical value of above-mentioned false dismissal probability is based on some basic inferences and obtains, only as the reference of practical application.May consider following problem in practice:

1, the aforementioned calculation result supposes that the longitude of positioning result, latitude numerical value all belong to normal distribution, and both are independent; This is that a kind of of actual conditions is similar to;

2, the aforementioned calculation result is based on that measured data statistical value in the Galileo company obtains, and other local numerical value may be different therewith, and therefore surveying probability may be variant with The above results;

3, The above results is based on and obtains under the situation of desirable initialization longitude and latitude, can not obtain desirable initialization longitude and latitude numerical value fully in the reality, and therefore surveying probability may be variant slightly with The above results

According to client's requirement, in conjunction with the bearing accuracy of GPSONE, acceptable false-alarm probability, false dismissal probability and displacement are determined an alarm threshold.

1. the initial longitude and latitude setting of monitored terminal

Obtain locator data by CDMA/GPSONE module serial ports output, get average and this locator data is write terminal inner FLASH after locating 30 times continuously, be set to the initialization longitude and latitude of terminal.

2. locating and monitoring

Monitor terminal was located once according to client's the every fixed interval of the demand time, the data that obtain after at every turn locating is kept at FLASH dashes, and calculate these data with the distance between the initialization longitude and latitude by 2 range formulas.

After calculated distance surpasses alarm threshold, think that then monitored article have moved certain scope and reported the center; If do not exceed alarm threshold, then the terminal standby dormancy is up to locate next time.

3. the self-adaptive initial longitude and latitude is provided with

To be every day a time unit, carry out the adjustment of initialization longitude and latitude.

If alarm condition did not take place the same day, the longitude and latitude data that will preserve the same day are added up.Calculate the mean value E of this day N positioning result, this E is replaced former E, promptly calculate the initialization longitude and latitude make new advances and replace originally,, reach the adjustment of self-adaptive initial longitude and latitude to upgrade this every day.

4. adaptive alarm threshold setting

To be every day a unit, carry out the adjustment of adaptive alarm thresholding.

If alarm condition did not take place the same day, the longitude and latitude data that will preserve the same day are added up.Calculate this day N positioning result standard deviation sigma, this standard deviation sigma is replaced former σ, calculate the alarm threshold value make new advances and replace originally,, reach the adjustment of adaptive alarm thresholding to upgrade this every day.

Illustrate: the data in this invention produce down for client's specific demand, and verify through actual product.Wherein the invention of self-adaptive initial longitude and latitude and adaptive alarm thresholding is for the decline of false-alarm false dismissal probability of the monitoring series products effect that improves significantly, and algorithm wherein is of universal significance.Can select for use different calculation of parameter to go out different numerical value along with different needs, reach adaptive setting.

Protection explanation of the present invention:

This product now begins to be applied in the goods monitoring system, voltage stabilizing trickle charging circuit pattern wherein and sleep state house dog switch mode can greatly reduce the power consumption to the power requirement of system power supply and saving total system, and product can be worked long hours.Inner by being new pioneering invention for the autonomous judgment model of false-alarm false dismissal minimum probability and self-adaptive initial longitude and latitude and alarm threshold, the effect of the GPSONE indoor positioning data processing by the later stage has been obtained improving greatly, make by after the GPSONE indoor positioning, autonomous monitoring, the judgement of whether moving a segment distance becomes possibility.

The specific embodiment of the present invention:

Embodiment based on the autonomous device monitoring technique of indoor positioning is as follows:

1) the initial longitude and latitude setting of monitored device;

2) initial alarm threshold setting;

3) current mean bias is monitored;

4) current positioning error is monitored;

5) adaptively changing alarm threshold.

Claims (8)

1, a kind of adaptive self-monitoring device based on indoor positioning, this device has communication module, memory module, sensor, switch, CPU, interface, crystal oscillator and power supply, it is characterized in that comprising: control monitoring modular (10) and power management (20) module, interconnect by interface signal line therebetween, whole terminal interconnects by CDMA1X link and center control port, wherein:

Control monitoring modular (10) is by memory module (1), RS232 serial ports (2), control module CPU (3), communication module (4), crystal oscillator (5) and observation circuit (6) are formed, the input/output port of memory module (1) and RS232 serial ports (2) is connected with the I/O mouth of control module CPU (3) respectively, the input/output port of control module CPU (3) is connected with the I/O mouth of communication module (4) respectively, the output port of crystal oscillator (5) and observation circuit (6) is connected with the input port of control module CPU (3) respectively, and the output port of communication module (4) is connected with the input port of antenna (11);

Power management (20) module is made up of charging circuit (7), battery (8) and power supply (9), the input port of charging circuit (7) is connected with external direct-flow input signal line, and the output port of charging circuit (7) is connected with the input port of battery (8) with power supply (9) respectively.

2, adaptive self-monitoring device based on indoor positioning according to claim 1, it is characterized in that: the input/output port of described control module CPU (3) or be connected with the I/O mouth of watchdog chip (30), the output terminal of control module CPU (3) is connected with the input end of house dog switch (a 301) circuit of watchdog chip (30) via switch (12) back, another output terminal of control module CPU (3) is connected with hello dog input pin (303) via feeding dog (14) signal wire, and the output pin that resets (302) of watchdog chip (30) is connected with the resetting pin (13) of control module CPU (3).

3, the adaptive self-monitoring device based on indoor positioning according to claim 2 is characterized in that: control module CPU (3) pin 1 of described house dog switch (301) circuit interconnects with the pin 7 of watchdog chip (30); The pin 6 of one tunnel and watchdog chip (30) of control module CPU (3) pin 2 interconnects, and another road is via resistance R 213 back ground connection; Control module CPU (3) pin 3 is connected with optocoupler pipe (304) pin 1 via resistance R 210 backs; Optocoupler pipe (304) pin 2 ground connection, optocoupler pipe (304) pin 3 is connected with the pin 8 of watchdog chip (30), and optocoupler pipe (304) pin 4 is connected with the pin 1 of watchdog chip (30) via resistance R 211 backs; Pin 3 ground connection of watchdog chip (30); The pin 2 of watchdog chip (30) connects power supply.

4, the adaptive self-monitoring device based on indoor positioning according to claim 1 is characterized in that: described power supply is connected with power module, battery (8), digital control circuit (106) and the port of communication module (4) respectively, wherein:

Direct current input 12V1A (101) signal divides two-way output, and one the tunnel exports 3.3V (104) back via power module 6V output A (102) with power module is connected with an input end of digital control circuit (106); Another road is connected with a input end that power module is exported 3.3V (104) after via power module 6V output B (103) and battery (8) circuit; Another output terminal of power module 6V output A (102) is exported 4.2V (105) back via power module and is connected with an input end of communication module (4).

5, the adaptive self-monitoring device based on indoor positioning according to claim 4 is characterized in that: the pin 1 of described battery (8) circuit U 101 modules (703) is connected with DC voltage input (701) signal wire;

Pin 5 is connected with charging control switch (702) signal wire;

A road of pin 3 is connected another road ground connection via resistance R 111 back with charging control switch (702) signal wire;

A road of pin 2 has four tunnel output signals after inductance L 101, first via feedback is connected with pin 4 via resistance R 104, the second the tunnel is connected with the output port of battery voltage detection (705) via schottky diode D104 and resistance R 105 backs, Third Road is via capacitor C 106 back ground connection, and the four the tunnel via capacitor C 105 back ground connection; Another road of pin 2 via schottky diode D103 after ground connection;

Pin 4 a road via resistance R 103 back ground connection, there are two tunnel output signals on another road after via resistance R 104, the first via is divided into two-way again after via schottky diode D104 and resistance R 105, one the tunnel via being connected with cell voltage output (704) signal wire behind the schottky diode D105, another road is via switch and battery (8) back ground connection, and the extension line between switch and battery (8) is battery voltage detection (a 705) signal wire; The second the tunnel via capacitor C 105 back ground connection.

6, a kind of adaptive self method for supervising based on indoor positioning is characterized in that: this method arrives optimal ratio by the analysis join probability opinion of locator data mathematical distribution with false-alarm, this parameter regulation to contradiction of false dismissal probability; And by adaptive algorithm, constantly the real-time update data parameters reaches the systematic error that the solution indoor positioning causes; This method comprises: the initial longitude and latitude setting of monitored device; Initial alarm threshold setting; Current mean bias monitoring; Current positioning error monitoring and adaptively changing alarm threshold; Its concrete job step is:

Step 1. initialization (40)

At first carry out system module initialization (40), obtain locator data, get average and this locator data is write terminal inner flash memory FLASH after locating 30 times continuously, be set to the initialization longitude and latitude of terminal by CDMA/GPSONE module serial ports output;

Step 2. locating and monitoring

The output signal of system module initialization (40) is divided into two-way, and one the tunnel for entering comparison (41) module, and positioning result is compared with alarm threshold; Another road enters location (46) module, monitor terminal was located once according to client's the every fixed interval of the demand time, the data that obtain after at every turn locating are kept among the flash memory FLASH, and calculate these data with the distance between the initialization longitude and latitude by 2 range formulas;

Step 3. is (41) relatively

Relatively the output signal of (41) module is divided into two-way, and one the tunnel reports center (47) module for entering, when calculated distance above behind the alarm threshold, think that then monitored article have moved certain scope and reported center (47);

Another road enters alarm threshold (42) module, when calculated distance does not exceed alarm threshold, think that then monitored article are not for moving, obtain last workaday positioning result, self-adaptation change alarm threshold (42), then terminal standby dormancy, if there is not dispatch from foreign news agency, real-time clock RTC then is set regularly, close house dog, enter sleep pattern (43), after real-time clock RTC look-at-me, enter real-time clock RTC and interrupt waking (44) up again, open house dog, enter location (46) module again, up to locate next time;

If dispatch from foreign news agency is arranged, real-time clock RTC regularly (45) then is set, after real-time clock RTC look-at-me, enter location (46) module more again;

Step 4. moves and reports center (47)

Movable signal enters and reports the output signal of center (47) module to be divided into two-way, one the tunnel is no dispatch from foreign news agency, real-time clock RTC then is set regularly, close house dog, enter sleep pattern (43), in real-time clock RTC, have no progeny again, enter real-time clock RTC and interrupt waking up (44), open house dog, enter location (46) module again;

If dispatch from foreign news agency is arranged, real-time clock RTC regularly (45) then is set, after real-time clock RTC look-at-me, enter location (46) module more again;

Step 5. is provided with the self-adaptive initial longitude and latitude

To be every day a time unit, carry out the adjustment of initialization longitude and latitude;

If alarm condition did not take place the same day, the longitude and latitude data that will preserve the same day are added up, and calculate the mean value E of this day N positioning result, this E is replaced former E, promptly calculate the initialization longitude and latitude make new advances and replace originally,, reach the adjustment of self-adaptive initial longitude and latitude to upgrade this every day;

Step 6. is provided with the adaptive alarm thresholding

To be every day a unit, carry out the adjustment of adaptive alarm thresholding;

If alarm condition did not take place the same day, the longitude and latitude data that will preserve the same day are added up, and calculate this day N positioning result standard deviation sigma, this standard deviation sigma is replaced former σ, the alarm threshold value that calculating makes new advances is also replaced originally, to upgrade this, reaches the adjustment of adaptive alarm thresholding every day.

7, the adaptive self method for supervising based on indoor positioning according to claim 6 is characterized in that: described alarm threshold is for obtaining the numerical value of corresponding alarm threshold by calculating, its concrete calculation procedure is:

If step 1. normal distribution

O is the initial point of two-dimensional coordinate with the terminal permanent datum, supposes that the terminal positioning result belongs to normal distribution with respect to the coordinate X and the Y of initial point, and both are independent, and variance is respectively σ _x, σ _yThen its joint probability density function is:

$f(x,y)=\frac{1}{2{\mathrm{\&pi;\&sigma;}}_x{\mathrm{\&sigma;}}_y}{e}^{-\frac{x^2{{\mathrm{\&sigma;}}_y}^2+y^2{{\mathrm{\&sigma;}}_x}^2}{2{{\mathrm{\&sigma;}}^2}_x{{\mathrm{\&sigma;}}^2}_y}}$

Step 2. is if positioning result exceeds radius

If positioning result exceeds the circle that radius is R, then false-alarm has taken place in expression, and its probability calculation formula is:

$1c\left(R\right):={[1-{\&Integral;}_{-R}^R{\&Integral;}_{-\sqrt{R^2-x^2}}^{\sqrt{R^2-x^2}}\frac{1\&CenterDot;e^{\left(\frac{{{\mathrm{\&sigma;}}_x}^2{y}^2+x^2{{\&CenterDot;\mathrm{\&sigma;}}_y}^2}{-2{{\&CenterDot;\mathrm{\&sigma;}}_x}^2{{\&CenterDot;\mathrm{\&sigma;}}_y}^2}\right)}}{2{\&CenterDot;\mathrm{\&pi;}\&CenterDot;\mathrm{\&sigma;}}_x{\&CenterDot;\mathrm{\&sigma;}}_y}\mathrm{dy\; dx}]}^1$

Wherein: establish σ _xThe standard deviation of expression longitude, σ _yThe standard deviation of expression latitude is got σ _x=200, σ _y=120, R is an alarm threshold;

8, the adaptive self method for supervising based on indoor positioning according to claim 6, it is characterized in that: the concrete calculation procedure of described false dismissal probability is:

If step 1. normal distribution

Represent that with an O average of two-dimentional normal distribution, left side radius are the circle expression false dismissal scope of R, in case test point drops on this zone, just false dismissal has taken place in expression;

Step 2. computing formula

The computing formula of its probability is as follows:

$\mathrm{func}\left(d\right)=\left[{\&Integral;}_{-R}^R{\&Integral;}_{-\sqrt{R^2-x^2}}^{\sqrt{R^2-x^2}}\frac{1-e^{\left[\frac{{{\mathrm{\&sigma;}}_x}^2{y}^2+{(x-d)}^2{{\&CenterDot;\mathrm{\&sigma;}}_y}^2}{-2{{\&CenterDot;\mathrm{\&sigma;}}_x}^2{{\&CenterDot;\mathrm{\&sigma;}}_y}^2}\right]}}{2\&CenterDot;x{\&CenterDot;\mathrm{\&sigma;}}_x{\&CenterDot;\mathrm{\&sigma;}}_y}\mathrm{dy\; dx}\right]$

Wherein, R represents alarm threshold, and d represents measuring distance, σ _xExpression longitude standard deviation, σ _yExpression latitude standard deviation.

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