CN202383295U

CN202383295U - GPS navigation positioning receiver

Info

Publication number: CN202383295U
Application number: CN2011204564683U
Authority: CN
Inventors: 高法钦
Original assignee: Zhejiang Sci Tech University ZSTU
Current assignee: Zhejiang Sci Tech University ZSTU; Zhejiang University of Science and Technology ZUST
Priority date: 2011-11-17
Filing date: 2011-11-17
Publication date: 2012-08-15
Anticipated expiration: 2021-11-17

Abstract

Disclosed is a GPS navigation positioning receiver, capable of presenting positioning result and rapidly carrying out repositioning even if the star is lost. The GPS navigation positioning receiver comprises an antenna, an amplifier, an RF front circuit, a baseband signal processing circuit, and a positioning display circuit which are sequentially connected, wherein the baseband signal processing circuit comprises a tracking-capture module, a synchronization and navigation message extraction module, a star-selection calculating module, an observed quantity calculating module, an error correction module, and a navigation positioning resolving module; the tracking-capture module is connected with an auxiliary information module; and the auxiliary information module comprises an inertia measuring unit. The inertia measuring unit can correctly convey the speed and other information of a receiver to the tracking-capture module, thereby making the tracking-capture module rapidly re-capture GPS signals for rapid repositioning and improving the positioning precision and continuity of the complete system. The GPS navigation positioning receiver is applicable to all the occasions that require navigation positioning.

Description

The GPS navigation location receiver

Technical field

The utility model relates to a kind of navigator fix equipment, especially relates to a kind of GPS navigation location receiver.

Background technology

Global position system be a kind of be the radio navigation system on basis with the satellite, round-the-clock, uninterrupted, high precision, real-time navigation positioning service can be provided for all kinds of carriers of land, sea, air.At present; Using the widest global position system is GPS of USA; Be penetrated into the every field of national economy and daily life, like sail, urban traffic control, commercial logistics management, the navigation of boats and ships ocean, when precision receives, geodetic surveying, precision agriculture etc.

The wrong situation of star or location appears losing in GPS easily under the situation such as high-speed mobile.It is the patent documentation of CN1708696A that State Intellectual Property Office of the People's Republic of China discloses publication number on Dec 14th, 2005; Title is the GPS receiver; This document discloses a kind of GPS receiver with an omnidirectional antenna and a directional antenna; It is configured to obtain one first gps signal from the output of said directional antenna separately; Perhaps combine with the output of said omnidirectional antenna and obtain one first gps signal, and obtain one second gps signal from the output of said omnidirectional antenna separately from the output of this directional antenna.The weak point of this scheme is, when owing to moving when the star problem occurring losing, is difficult to provide positioning result and reorientates.

Summary of the invention

The utility model mainly is to solve existing in prior technology GPS receiver to occur losing the deficiency that star can not in time provide accurate positioning result again owing to moving, and a kind of GPS navigation location receiver that still can provide positioning result and reorientate rapidly behind the star of losing is provided.

The utility model mainly is able to solve through following technical proposals to above-mentioned technical matters: a kind of GPS navigation location receiver; Comprise the antenna, amplifier, RF front-end circuit, base band signal process circuit and the locating and displaying circuit that connect successively; Said base band signal process circuit comprises tracking and trapping module, synchronously and the navigation message extraction module, select star computing module, observed quantity computing module, error correction module and navigator fix to resolve module; Said catching with tracking module is connected with the supplementary module, and said supplementary module comprises Inertial Measurement Unit.Inertial Measurement Unit can accurately pass to the information such as speed of receiver and catch and tracking module, catches with tracking module and catches gps signal fast again according to information such as speed, thereby can reorientate rapidly.Adopt Inertial Measurement Unit assistant GPS navigation positioning receiver can improve its location sensitivity and anti-jamming capacity, and can improve the bearing accuracy and the continuity of total system.

As preferably; Said tracking and trapping module comprise first multiplier and second multiplier; The output terminal of said first multiplier connects first Discr. and second Discr.; The output terminal of said second multiplier connects first Discr. and second Discr., and the output terminal of said first Discr. and second Discr. all is connected with loop filter, and said loop filter also connects local code generative circuit and local carrier generative circuit respectively; Said local code generative circuit is connected with said second multiplier with said first multiplier; Said local carrier generative circuit is connected with second multiplier with said first multiplier, and said first multiplier is connected with RF front-end circuit with said second multiplier, and Inertial Measurement Unit is connected with said local carrier generative circuit.

As preferably, said supplementary module also comprises interconnective almanac data module and Doppler frequency estimation module, and said Inertial Measurement Unit is connected with said almanac data module, and said almanac data module is connected with said local carrier generation module.

As preferably, said loop filter is an adaptive Kalman filter.

As preferably, said first Discr. and second Discr. all comprise four-quadrant arc tangent Discr. and dot product type phase detector.Under the condition of feeble signal, adopt four-quadrant arc tangent phase detector as the loop Discr.; And under the condition of high s/n ratio, adopt dot product type phase detector as the loop Discr..

The beneficial effect that the utility model brings is, that the GPS navigation location receiver adopts is open, based on the universal integrated circuit chip of FPGA+DSP structure, can conveniently do 2 exploitations or with the other system combination so that improve performance; Can when losing star, provide positioning result and reorientating rapidly through Inertial Measurement Unit, the bearing accuracy in the time of can improving normal receipts star.

Description of drawings

Fig. 1 is a kind of module diagram of the utility model;

Fig. 2 is the module diagram of a kind of base band signal process circuit of the utility model;

Fig. 3 is that a kind of of the utility model catches and the tracking module structural representation;

Among the figure: 1, antenna, 2, the low-noise factor amplifier, 3, RF front-end circuit, 4, the base band signal process circuit, 5, the locating and displaying circuit; 41, tracking and trapping module, 42, synchronously and the navigation message extraction module, 43, select the star computing module, 44, the observed quantity computing module; 45, error correction module, 46, navigator fix resolves module, 101, first multiplier, 102, second multiplier; 103, first Discr., 104, second Discr., 105, loop filter, 106, the local carrier generative circuit; 107, local code generative circuit, 108, the almanac data module, 109, the Doppler frequency estimation module, 110, Inertial Measurement Unit.

Embodiment

Pass through embodiment below, and combine accompanying drawing, do further bright specifically the technical scheme of the utility model.

Embodiment: a kind of GPS navigation location receiver of present embodiment, as shown in Figure 1, comprise the antenna 1, low-noise factor amplifier 2, RF front-end circuit 3, base band signal process circuit 4 and the locating and displaying circuit 5 that connect successively.As shown in Figure 2, the base band signal process circuit comprises to be followed the tracks of with trapping module 41, synchronous and navigation message extraction module 42, selects star computing module 43, observed quantity computing module 44, error correction module 45 and navigator fix to resolve module 46.As shown in Figure 3; Tracking and trapping module comprise first multiplier 101 and second multiplier 102; The output terminal that the output terminal of first multiplier connects first Discr. 103 and second Discr., 104, the second multipliers connects first Discr. and second Discr., and the output terminal of first Discr. and second Discr. all is connected with loop filter 105; Loop filter also connects local code generative circuit 107 and local carrier generative circuit 106 respectively; The local code generative circuit is connected with second multiplier with first multiplier, and the local carrier generative circuit is connected with second multiplier with first multiplier, and first multiplier is connected with RF front-end circuit with second multiplier.Tracking and trapping module are connected with the supplementary module, and the supplementary module comprises Inertial Measurement Unit 110, Doppler frequency estimation module 109 and the almanac data module 108 that connects successively, and Inertial Measurement Unit is connected with the local carrier generative circuit.

Loop filter is an adaptive Kalman filter.First Discr. and second Discr. all comprise four-quadrant arc tangent Discr. and two kinds of Discr.s of dot product type phase detector.

That the GPS navigation location receiver of present embodiment adopts is open, based on the universal integrated circuit chip of FPGA+DSP structure, can do 2 exploitations easily or with other system in combination so that improve performance; In the inner micro electro mechanical inertia measurement mechanism unit (IMU) that embeds low-cost, low precision of GPS receiver; Can provide positioning result by IMU when losing star; And the assistant GPS receiver module is so that improve its speed of catching gps signal again and sensitivity; Thereby improve the bearing accuracy and the continuity of total system, adopt the GPS positioning result to estimate and proofread and correct the device error of IMU when normally receiving star, improve its bearing accuracy.

The receiver local decode need one with receive signal with the local carrier and the pseudo-code of homophase frequently; But because the influence of factors such as Doppler effect; The frequency and the pseudo-code phase of actual reception signal have uncertainty, and therefore, acquisition procedure is the two-dimensional search process (searching carrier more than 40 time of pseudo-code phase space and frequency space; The pseudo-code chip is searched for more than 1000 time), badly influence the real-time of location and the reliability of operation of receiver.

For addressing this problem, this patent adopts IMU assisting navigation receiver acquisition, dwindles the search volume; Improve acquisition speed: the almanac data of storing before utilizing extracts and predicts satellite velocities with least square method, and the movement velocity of the exportable receiver of IMU, therefore; Can calculate the speed of related movement between receiver and the satellite; Can calculate the change of frequency that causes because of relative motion according to Doppler's principle is Doppler frequency, and joins in pseudo-code and the carrier wave NCO circuit, revises local pseudo-code phase and local carrier frequency; Dwindled the hunting zone, the control capture circuit is realized catching fast.

Even receiver clock exists ± 1 minute error, site error to be ± 100Km, utilize the precision of ephemeris or the satellite motion Doppler frequency that the satellite almanac data is estimated in the week still to be superior to ± 150Hz; In the auxiliary DVB of little inertial navigation IMU, the estimated accuracy that the Doppler shift that the carrier dynamic causes changes is superior to 2Hz (be unlikely and cause the signal losing lock), and the frequency resolution of catching is ± 500Hz.It is thus clear that this patent is suggested plans and can be realized high catching fast under dynamically.

By preceding said; The Doppler shift variation range is bigger; This just requires the GPS receiver tracking loop circuit to have the bandwidth of broad, and reducing dynamic response error, but this can cause loop filter bandwidth to increase; Weakened the GPS receiver and considered the ability of removing noise, the tracking error that noise causes when serious also can make the dropout of catching.For addressing this problem, adopt IMU assistant GPS track loop in this patent.Because the estimated accuracy that the Doppler shift that the auxiliary carrier dynamic down of little inertial navigation IMU causes changes is less than 2Hz; Be lower than the track loop bandwidth, can prevent the satellite-signal losing lock, therefore; This scheme can be eliminated the Doppler frequency that relative motion is introduced between satellite and carrier, eliminates dynamic response error.

The closed loop combination can be revised the inner parameter of IMU; Make the navigation error of IMU remain at less level; Shortcoming be the state of element in the middle of continuous adjustment, system stability is poor, difficult realization the on engineering; Wave filter fault or metrical information can cause when having than mistake the mistake of IMU is proofreaied and correct, and system reliability is reduced.In order to overcome this drawback; The closed loop assembled scheme of this patent design GPS receiver module and IMU unit: the clocking error model is a state equation between first order filtering employing carrier movement model and corresponding GNSS star station; With pseudorange, pseudorange rates is observed quantity; Select open loop approach for use so that the stability and the reliability of the system of assurance; Second level filtering adopts the ins error propagation model simplified and device error model as system state equation, and as observed quantity, the mode that adopts closed-loop corrected inertial navigation is to reduce ins error with the difference of the measured value of pseudorange, pseudorange rates and IMU estimated value; Reduce and to lose IMU cell location error growth rate behind the star, thereby reduce combined system because of losing star, being disturbed the positioning error when causing satellite data unavailable.This scheme advantage is: it is closed-loop corrected whether (1) can freely determine to adopt time filtering to carry out according to receipts star situation, and do not influence the stability of system; (2) the navigational parameter error of IMU remains at less level; Positioning error when the positioning error when (3) closed loop is lost star is lost star than open loop is significantly little.

Under this assembled scheme, the angle increment that IMU measures, speed increment carry out the inertial navigation navigation calculation through after the error compensation; Satellite-signal carries out acquisition and tracking through the radio-frequency front-end amplification and after sampling, and when successful tracking signal, resolves information such as obtaining pseudorange, pseudorange rates.Then; The navigational parameter of IMU output and pseudorange, pseudorange rates etc. are inputed to the integrated navigation Kalman filter carry out optimal estimation; Estimate to obtain navigator fix output result's (position, speed etc.) on the one hand; Estimate on the other hand to obtain IMU device error, this error estimate is fed back to the IMU unit go to proofread and correct IMU device error, and; To feed back to receiver according to the velocity information of ephemeris velocity information and IMU and go assisted GNSS signal capture and tracking, so that keep the stable of track loop.

The velocity error of revising inertial navigation adopts pulse feedback to proofread and correct, and the velocity error that promptly obtains with system estimation feeds back to the instant correcting module of speed in the IMU inertial navigation layout equation, proofreaies and correct corresponding speed increment (directly from speed increment, deduct and get final product).

The Attitude Calculation flow process is generally following:

(1) presses certain intervals to gyro output sampling;

(2) calculate the angle (angle increment) that each gyro turns in a certain short period t according to sampled value;

(3) ask for the rotation resultant vector and upgrade hypercomplex number.

In superincumbent (2) step, deduct the error angle estimating to obtain (through after the coordinate conversion), will realize correction that gyro is exported so, thereby proofread and correct attitude error if will calculate angle increment (angle that gyro turns over).

Specific embodiment described herein only is that the utility model spirit is illustrated.The utility model person of ordinary skill in the field can make various modifications or replenishes or adopt similar mode to substitute described specific embodiment, but can't depart from the spirit of the utility model or surmount the defined scope of appended claims.

Although this paper has used tracking and terms such as trapping module, Inertial Measurement Unit morely, do not get rid of the possibility of using other term.Using these terms only is in order to describe and explain the essence of the utility model more easily; It all is contrary with the utility model spirit being construed to any additional restriction to them.

Claims

1. GPS navigation location receiver; Comprise the antenna, amplifier, RF front-end circuit, base band signal process circuit and the locating and displaying circuit that connect successively; It is characterized in that; Said base band signal process circuit comprises tracking and trapping module and synchronous and navigation message extraction module, and said catching with tracking module is connected with the supplementary module, and said supplementary module comprises Inertial Measurement Unit.

2. GPS navigation location receiver according to claim 1; It is characterized in that; Said tracking and trapping module comprise first multiplier and second multiplier; The output terminal of said first multiplier connects first Discr. and second Discr.; The output terminal of said second multiplier connects first Discr. and second Discr., and the output terminal of said first Discr. and second Discr. all is connected with loop filter, and said loop filter also connects local code generative circuit and local carrier generative circuit respectively; Said local code generative circuit is connected with said second multiplier with said first multiplier; Said local carrier generative circuit is connected with second multiplier with said first multiplier, and said first multiplier is connected with RF front-end circuit with said second multiplier, and Inertial Measurement Unit is connected with said local carrier generative circuit.

3. GPS navigation location receiver according to claim 2 is characterized in that, said loop filter is an adaptive Kalman filter.

4. GPS navigation location receiver according to claim 2 is characterized in that, said first Discr. and second Discr. all comprise four-quadrant arc tangent Discr. and dot product type phase detector.

5. GPS navigation location receiver according to claim 3 is characterized in that, said first Discr. and second Discr. all comprise four-quadrant arc tangent Discr. and dot product type phase detector.