CN101738621A

CN101738621A - Method for rectifying GPS positioning accuracy by motion sensor

Info

Publication number: CN101738621A
Application number: CN200910220179A
Authority: CN
Inventors: 徐永锋
Original assignee: Shenyang Chenxun Simcom Technology Co Ltd
Current assignee: Shenyang Chenxun Simcom Technology Co Ltd
Priority date: 2009-11-26
Filing date: 2009-11-26
Publication date: 2010-06-16

Abstract

The invention discloses a method for rectifying GPS positioning accuracy by a motion sensor. The method comprises the following steps: the motion sensor is adopted to assist in rectifying GPS positioning data and the motion sensor and a GPS tracking device are used to synchronously collect data; then motion direction is determined by acceleration data output by the motion sensor; coordinate data output by a GPS receiving module is screened according to the motion direction; the coordinate data featuring obvious wander is removed; finally mean value of the rest data is reported as the final result. With the method adopted, possibility of data wader can be reduced and positioning accuracy can be maximally reduced in a short span of time.

Description

A kind of method of utilizing motion sensor correction GPS bearing accuracy

Technical field

The present invention relates to GPS tracing and positioning technology, particularly a kind of method of utilizing motion sensor correction GPS bearing accuracy.

Background technology

" regularly report " is the mode of operation commonly used of GPS tracing and positioning equipment, promptly sends once report every several minutes (generally can be set to interval time 5 minutes, 10 minutes etc.), and interval time is longer.Under this mode of operation, the GPS batch (-type) is opened, and is far short of what is expected when its bearing accuracy is opened than GPS is normal, tends to take place bigger position location drift.

When GPS often opened, the GPS positional information can reach per second and upgrade once, therefore can remain the precision of data.And the mode of restarting after closing is divided into usually:

Cold start-up (receiver loses satellite parametric reduction, and parameter that has perhaps existed and real satellite parameter differ too much, can't work, and needs search of satellite again, stored parameter).

Startup temperature (have some satellites out of touch in the parameter that has searched, need to replenish again).

Three kinds of patterns of warm start (satellite that has searched and the actual satellite that can get in touch do not have to change substantially).

During practical application, adopt warm start or startup temperature usually, be warm start＜15 second the start-up time of general GPS receiver, startup temperature＜60 second, cold start-up＜2 minute, and that GPS starts the initial locator data precision that obtains in back is relatively poor, along with the increase of time, bearing accuracy just can progressively improve.

In the practical application, tracing and positioning equipment is in the persistent movement usually, and in normal on-mode, GPS receiving system itself can be made the judgement of movement tendency according to the front and back data, improves precision.Regularly report pattern, the information that receives after restarting is not because of there being other data can reference, and precision own is relatively poor, adding receiving equipment is in and moves, need the more time of cost to carry out data accumulative total, correction, though the opening time is long more, the locator data of obtaining is accurate more.But also very high in the practical application to the time requirement that reports, can not wait guarantee bearing accuracy for a long time, therefore can only weigh the advantages and disadvantages, carry out balance between the two in precision and time, caused the position excursion of certain probability.Therefore, should manage to reject GPS location drift data, to improve the bearing accuracy of GPS tracing and positioning equipment.

Motion sensor also is " three dimension acceleration sensor ", before and after detecting, about, the variation of acceleration on 3 directions up and down, (z) accekeration of direction is represented the size of acceleration on this direction respectively for x, y can to provide 3 respectively.Should with in only use x, the y diaxon as shown in Figure 2, can be judged the direction of motion of carrier according to its output data.

Summary of the invention

The object of the present invention is to provide a kind of method of utilizing motion sensor correction GPS bearing accuracy.

Technical scheme of the present invention is: the GPS tracing equipment of band motion sensor is when regularly detecting the present position, allow GPS and motion sensor synchronous acquisition data, determine the direction of motion of equipment then according to the output of motion sensor, direction of motion is the data of standard screening GPS receiver module output according to this again, obviously drift takes place in rejecting, and the mean value of getting remaining data again is as reported data.

Only use motion sensor x among the present invention, the status data of y diaxon (accekeration).

Method of the present invention can reduce the possibility of data-bias, but improves locating accuracy within a short period of time to greatest extent.For example, each location is got 5 data continuously, if the represented point of these 5 data can be linked to be a straight line or smooth curve, represent that then data are continuous, undergo mutation as middle certain point, not in straight line or curve ranges that other points couple together, represent that then drift has taken place these data, directly reject.And then the mean value of getting those remaining position datas reports as net result.

Description of drawings

Fig. 1 is hardware platform required for the present invention (the GPS tracing equipment of band motion sensor)

Fig. 2 is a motion sensor direction of motion area schematic

Fig. 3 is the process flow diagram of specific embodiment

Embodiment

The formation of the GPS tracing equipment of this example: direction of motion detection module (10) (mainly forming), GPRS sending module (2), GPS receiver module (3) and main control chip (5) and storer (6) by the monolithic control chip (4) of motion sensor (1) and low-power consumption.

That direction of motion detection module motion sensor uses is the three dimension acceleration sensor MMA7260QT of Freescale (Freescale), should with in only use X, Y bidimensional, measurement range is positive and negative 1.5~6g，(1g＝9。8m/s)。With the microcontroller MC9S08Q of Freescale,, convert the analog quantity of the reflection acceleration magnitude of MMA7260QT output between the 0-255 digital value by the A/D change-over circuit in the microcontroller.The scope of two dimension output valve can be judged the direction of motion of carrier in two-dimensional space as shown in Figure 2 in view of the above.Its

The GPRS sending module is based on radio frequency chip RPF08155B, support four frequency ranges of 850/900/1800/1900MHz, GSM900 partly is 4 classes, and GSM1800 partly is 1 class, and GPRS partly is category-B class 10GPRS transfer table (supporting CS1, CS2, CS3, CS4).

The GPS receiver module uses the GSC3f/LPx chip of SiRFstarIII framework, frequency of operation: L1,1575.42MHz supports 20 port numbers.

Main control chip uses Lian Fake (MTK) the MT6223 baseband processing chip based on the ARM7 kernel, highest frequency reaches 52MHz, the storer that is used is the MCP storage chip TV00570002CDGB of TOSHIBA, and this chip has comprised the NOR Flash of 4MByte static RAM (SRAM) and 16MByte.

Concrete implementing procedure of the present invention now is described as follows as shown in Figure 3:

Step 110: regularly report pattern, timing arrives, the beginning positioning action;

Step 120: start GPS receiver module (3) and direction of motion detection module simultaneously, press per second frequency once, continuous acquisition n data (value of n can determine according to actual effect, considers the actual computation ability of actual request for utilization and terminal platform, and the n value is between 5 ~ 20) separately.Get n=5 in the present embodiment, i.e. the status data of 5 GPS position datas of continuous acquisition and 5 motion sensors, write store (6);

Step 140: these 5 status datas that relatively collect earlier from motion sensor (1), see whether these group data all point to same direction; If be not to point to same direction, variation has taken place in the direction of motion that is illustrated in GPS tracing equipment in the data acquisition, gives up this group data, returns step 120 and gathers again; If all point to same direction, then enter next step;

Step 150: after knowing the direction of motion of GPS tracing equipment by the output data of analyzing motion sensor, connect into a line by calculating those 5 GPS position datas that will collect again, suppose that direction of motion is X+, then this line should be smooth curve or the straight line in X+ direction 90 degree fan sections, obviously protrude in this curve or straight line as certain data in this group gps data, then these data are abnormal datas, are rejected;

Step 160: and then get the mean value of remaining GPS position data, with this mean value as the GPS position data that finally reports;

Step 170:, will send through the GPS position data of revising by GPRS sending module (2), closing movement direction detection module (10), GPS receiver module (3), GPRS sending module (2) are waited for Location Request next time then.

Claims

1. method of utilizing motion sensor correction GPS bearing accuracy, its GPS tracing equipment that is characterised in that the band motion sensor is when regularly detecting the present position, determine the direction of motion of equipment earlier according to the output of motion sensor, direction is the data of standard screening GPS receiver module output according to this again, obviously drift takes place in rejecting, and the mean value of getting remaining data again is as reported data.

2. a kind of method of utilizing motion sensor correction GPS bearing accuracy according to claim 1 is characterized in that GPS and motion sensor synchronous acquisition data.

3. a kind of method of utilizing motion sensor correction GPS bearing accuracy according to claim 1 is characterized in that only using motion sensor x, the status data of y diaxon (accekeration).

4. a kind of method of utilizing motion sensor correction GPS bearing accuracy according to claim 1 is characterized in that the GPS tracing equipment comprises the acceleration detection module, mainly is made up of the monolithic control chip of acceleration transducer and low-power consumption; The GPRS sending module, GPS receiver module, main control chip and storer.