GPS Asset Tracker Systems GPS monitoring (in Shanghai, even the GPS in-car terminals, for example in information technology) is a GPS technology, wireless communication technology (GSM/GPRS/CDMA), image processing technology and GIS technology, people, pets, vehicles used to move a foreign technology and equipment for remote real-time monitoring.
With GPS monitor can do the following:1. Tracking and positioning
Monitoring Center to all-day 24 hour monitoring of all charged of real-time vehicle location, direction of travel, speed, to timely grasp the State of the vehicle.
2. Track playback
Monitoring Center can play back at any time within 60 days of custom vehicle history tour, track record. (Depending on the circumstances, matching trajectory burn DVD services)
3. Alarm (report)
3.1, speeding alert: when the vehicle speed exceeds the preset speed monitoring centre, timely reporting monitoring center
3.2, zone alarm (electronic fence): setting zone-wide monitoring center, traffic beyond or into a preset region to the monitoring and dispatching Center gives the corresponding alarm
3.3, stop report: to stop vehicle history records the dispatch Center can generates a report in the form of text, which describes the vehicle parking information such as location, time and driving time, and can be printed.
4. Map features
According to the viewing needs, customers can add a modified custom maps lines to better service enterprise running
5. Mileage statistics
Logging system using GPRS vehicle terminal driving and GIS geographic system on vehicle mileage statistics and reports can be generated and can be printed.
6. Vehicle information management
User-friendly management platform, providing vehicles, drivers, vehicle information such as pictures of the set, to facilitate the work of dispatchers.
7. SMS notification feature
Various alarm or status of the vehicles will be charged when necessary, to send information to managers on the phone in order to master the important State of vehicle information anytime, anywhere.
8. Vehicle remote control
Remote Monitoring Center may at any time on the vehicles fuel cut power off, lock the car features.
9. Car phone
Mobile phone can be drawn as ordinary phone calls, dispatch Center can set remote permissions on this phone, namely the barring of incoming calls, outgoing limit, can only call several phone numbers you specify.
10. Fuel consumption measurement
Real-time monitor the vehicle’s fuel consumption and generates report amount of oil or oil change graphs historical time period, then reflected out non-normal and normal consumption of oil consumption and fuel shortage phenomenon, achieving fuel consumption level management, prevent adverse events occur. (Need to mix fuel level sensor)
11. Vehicle scheduling
Scheduling staff scheduling dispatching scope painted on the vehicle or on the map, draw set automatically to the vehicle or the GPS system issued a scheduling order for all vehicles in the area, was timely response dispatch Center dispatch vehicles to determine the implementation of the orders. GPS system can also be successfully dispatch number month per vehicle.
How GPS monitoring capabilities to achieve GPS monitoring function must have the GPS Terminal, transport network and monitoring platform of the three elements, these three elements are indispensable. Through these three elements, comprising three-layer structure of the monitoring system, applied in the field of vehicle scheduling and monitoring, can provide vehicle anti-theft, anti-robbing, route monitoring and call features such as command; applications in the field of human pet tracking, can provide for the elderly, children and pet tracking, the elderly, the children encounter when emergency calls for help, and other functions. GPS monitoring and control of three elements: GPS Terminal, monitor and control platform, transport networks, etc.
GPS Terminal
GPS Terminal is GPS monitoring and control system of the front-end devices, or generally secretive installed in various vehicles carry people or pets, GPS terminal equipment is used primarily by the main CPU, a GPS module, GPRS module , I/O interface and the external circuit.
Monitoring platform
Monitoring platform is GPS monitoring of core, is remote Visual command and monitoring management platform, once in vehicles Shang installation GPS monitoring device or in people who wear has GPS monitoring device, device Shang of GPS module will real-time to will car or people of location information through wireless network sent to monitoring center, in monitoring center of electronic map Shang can see vehicles, and people or pet is located of intuitive location, monitoring center can through wireless network on vehicles, and people or pet for remote monitoring, also can on device for set, for example through issued directive set upload interval, and remote heavy Kai device,.
Transmission network
You can use GPRS or CDMA wireless communication network in wireless communication networks, SMS can also be used for data transmission.
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GPS monitoring and control system functions and features overview
GPS monitoring
(1) immediate query
When the monitoring centre immediately after the command, GPS Terminal timely upload location information vehicles, people or pets (including longitude, latitude, azimuth, speed, number of satellite and other information) and status information.
(2) remote tracking
On monitoring center monitor software of GPS Terminal for scheduled tracing settings, you can set a fixed time upload location information and status information, once successful, GPS Terminal in accordance with the instructions issued by the monitoring center requests information required to timely upload the monitoring center.
(3) emergency
When the driver, or when individuals encounter special situations for worn GPS Terminal, to the monitoring Center for help through the emergency button. Once the monitoring centers received calls for help instructions, monitoring or police assistance Center staff can provide assistance.
(4) historical track playback
History in motion playback, the system can view history information in a day where vehicles, people or pets in, walking that line. Then what is the vehicle’s status info;
Features of the GPS monitoring
Features for real-time, dynamic, two-way GPS monitoring and precise.
Application of GPS monitoring
Main application vehicle GPS monitoring scheduling monitoring industry, GPS manufacturers in recent years have also introduced a GPS monitoring device suitable for the elderly, children, and so use, there are specialized dispatching equipment developed for employees of the company, such as the recipient of the Courier industry with GPS monitoring devices, transmitting position, easy company commanding.
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Application of GPS monitoring
Vehicle Terminal
-Vehicle terminals include: control unit (CPU), the display unit (optional), GPS, GPS antenna, GSM cell phone (or other communication module), burglar alarm, etc. Major features such as alarm, navigation, call.
Wireless data-link
Wireless data transmission devices as a base station and mobile destination hub for information exchange, is an important component of vehicle scheduling system as a whole, whose options include the following: first, public network equipment: GSM, and CDMA, and CDPD (wireless public network). II, trunking communication: such as public security with 350M, 800M on cluster systems. ⅲ, conventional radio: using dedicated channels and wireless MODEM.
The monitoring center
Control center equipment including: database, Terminal/GIS Terminal, terminal business processing, front-end access equipment. Staff through mobile target monitoring system monitors all network campaigns. The key is an appropriate database, electronic maps, as well as the construction of business content and business contents closely related application software-MIS, vehicle scheduling, monitoring, information to achieve major functions such as query.
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System composition
(1) in-vehicle GPS master(2) SIM card
(3) the Communications Server
(4) The database server
(5) management software
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Vehicle positioning system
Application of GPS in vehicle management, called vehicle location system .
GPS vehicle management system features a simple description
1, real time monitoring: application of Mobile GPRS GPS vehicle management system for monitoring the data carrier, the real live monitoring of the realization of the vehicle (such as speed, direction), the monitoring frequency is 1 second level.
2, driving information management: System for vehicles traveling in the past such as data download, playback, saving the information.
3, speeding alert: Administrators individually, or set a lower bound on the speed of all vehicles, when the vehicle speed exceeds the limit, the system will prompt the speeding alarm and is followed by sound and window pop-up window prompts.
4, building their own layer: Administrators can use the text and images on the map marked on their own company and site position; can also build a road that is not on the line, better perfect the map to manage the vehicle.
5, text management: management by way of writing the text for a car or a group of vehicles dispatching information. Information sent will be preserved, for later verification.
6, speeding alarm statistics: data saved by system functions, can in hindsight be a car in one day on a day of traffic data for a certain period of time for playback, and can generate reports for, this feature can be used for evaluation.
7, lane line tracking: real-time records for single or all vehicles driving routes feature, when after the vehicle is drawing a black line on the map, administrators can visually see vehicles traveling routes.
8, zone alarm function: you can set restricted areas, as a car into monitoring alert reminder. Custom driving route, when the driver left the driving route scheduled alarm.
10, perfect admin management functions:
(1) vehicle information management can query the vehicle information, statistics, adding, deleting, modifying maintenance work.
(2) you can assign permissions to administrators, for grading, multi-level management.
(3) log management, such as login log, alarm settings, the message is sent to statistics, print, and delete
11, gas mileage statistics: through a system-supplied data-preservation functions, one day a car can be a day of a road mileage and fuel consumption over time, can generate a report for printing, this feature can be used for reference.
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GPS positioning systems for navigation
GPS navigation system of the basic principle is to measure the distance between the known location of the satellite to the user’s receiver, and multiple satellite dataYou can tell that receiver’s location. To achieve this aim, position of the satellite can be recorded according to the clock on satellite in the satellite ephemeris time found out. And user to satellite of distance is through records satellite signal spread to user by experience of time, then will its multiplied by speed get (because atmosphere ionospheric of interference, this a distance is not user and satellite Zhijian of real distance, but pseudo from (PR): Dang GPS satellite normal work Shi, will constantly to with 1 and from the into system code Yuan composition of pseudo random code (short pseudo code) Launch navigation message. GPS system using PN code in all of two, namely the C/A codes of civil and military p (Y) code. Frequency of C/A codes 1.023MHz, repeat the cycle a millisecond, code within 1 microsecond, the equivalent frequency 10.23MHz 300m;P code, repeat cycle 266.4 days, code spacing of 0.1 microseconds, equivalent to 30m. Y-codes are formed on the basis of the p-code, security will be better. Navigation message includes the satellite ephemeris, working conditions, atmospheric refraction correction clock correction, ionospheric delay correction, and other information. It solution for modulation is a signal from the satellite, launched to 50B/s modulation carrier frequency. Each navigation message contains 5 frame every frame in the main frame 6s longer. First three frames each 10 Word; repeat every 30 seconds, updated once an hour. Two frames after a total of 15000b. Telemetry main content navigation message code, the conversion code, 1th, 2, 3 blocks, the most important of the ephemeris data. When the user accepts to when a navigation message, extract the satellite time and in addition their comparative distance will be known satellites and the user, then use the navigation satellite ephemeris data message when extrapolating satellite launch message location, user location in the WGS-84 of geodetic coordinate system information such as speed will be known.
Role of visible GPS satellite navigation system part is constantly launching navigation message. However, because the user accepted for the use of clock synchronized with satellites onboard clock is not always, therefore, in addition to the three dimensional for users outside the coordinate x, y, z, also to introduce a δ t between the satellites and receivers of the time difference as unknowns, then 4 equations 4 unknowns work out. So if you want to know the location of the receiver, must receive at least 4 satellite signals.
GPS receiver can received to available Yu timing of accurate to is satisfied that seconds level of time information; for forecast future several months within satellite by Department general location of forecast star calendar; for calculation positioning Shi by required satellite coordinates of broadcasting star calendar, precision for several m to dozens of m (each satellite different, at any time changes); and GPS system information , as satellite status,.
GPS receivers on code distance measurement you can get a satellite to the receiver, because it contains receiver satellite clock errors and atmospheric propagation of error, so called pseudo. 0 a pseudo code measured is called UA code pseudorange, accuracy of about 20 meters, measured on the p-code pseudorange called p-code pseudorange, accuracy of about 2 meters.
GPS receiver for satellite signal received, decode or use other technology, modulated on a carrier of information after you remove, you can restore carrier. Strictly speaking, carrier phase should be referred to as carrier beat phase, it was received under the influence of Doppler frequency shift of the satellite signal carrier phase oscillation signal phase difference between the native and receiver. Receiver clock in General determine the epoch time of measurement, keeps track of the satellite signal, you can record the phase changes of value, but when it started observing satellite and receiver oscillators the phase of initial value is not known, the starting phase integer epoch is not aware of, that is, integer ambiguity, only in the calculation as a parameter in the data processing. High precision phase observation to mm, but the premise is to work out the whole ambiguity, so only the relative positioning, and can only be used when there is a continuous observations phase observation, to be superior to the metre-level positioning accuracy also use the phase observation only.
By positioning, GPS positioning is divided into single-point positioning and relative positioning (differential positioning). Point positioning is based on the observation data for a receiver to determine how the receiver position, it can only adopt pseudorange measurements, can be used for travel, general navigation. Relative positioning (differential positioning) is based on observation data of more than two receivers to determine the method of relative position between observation points, which can be used both pseudorange measurements with measurements can also be used for phase, geodetic measurements or engineering phase observation in relative positioning should be used.
In GPS view measurement in the contains has satellite and receiver of Bell difference, and atmospheric spread delay, and more path effect, errors, in positioning calculation Shi also to was satellite broadcasting star calendar errors of effect, in for relative positioning Shi most public errors was offset or weakened, therefore positioning precision will greatly improve, double frequency receiver can under two a frequency of observation volume offset atmospheric in the ionospheric errors of main part, in precision requirements high, receiver between distance more far Shi (atmospheric has obvious differences), should selection double frequency receiver.
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System includes three major parts
GPS positioning system consists of three parts: the space segment satellite constellation-GPS; ground control segment-ground monitoring system; user equipment part-GPS receivers for signals.
GPS satellite constellation
GPS satellite constellation and its 21 working satellites and 3 spare satellites in orbit GPS satellite constellation is recorded as (21+3) GPS constellation. 24 satellites are evenly spaced in the 6 orbital plane and orbit inclination angle is 55 degrees, each 60 degrees apart between the orbital plane, that is, tracks of the ascending node right ascension difference of 60 degrees. Various satellites each orbit plane rise angle difference in pitch between 90 degrees, a satellite on the orbit plane adjacent to appropriate satellite on the orbit planes than the West ahead of 30 degrees.
GPS satellites 20,000 kilometers altitude, when the Earth to the star’s rotation when a week, they run two weeks around the Earth, that is, when the time of 12 stars around the Earth for a week. Thus, for observers on the ground, 4 minutes earlier every day to see the same GPS satellite. Number of satellites located above the horizon varies with time and place, visible to at least 4 satellites, can meet up to 11. At the time of navigation with GPS signal, in order to settle station coordinates must be observed 4 GPS satellites, known as positioning constellation. This geometry of 4 satellites in the observation process have certain effects on positioning accuracy of position distribution. For some time somewhere, can’t even get accurate coordinates of points, this time period is called the “gap”. But this time gap is very short, not affecting most places in the world clock, high precision, male banana ㄎ spiral put in order in real time in a row June? Number of GPS satellites and the test satellite is basically the same.
Ground control system
For navigation, and GPS satellite is a dynamic known points. Ephemeris of the star’s position is based on satellite launch-that describes the parameters of the satellite motion and orbit can count. Each GPS satellite broadcast ephemeris, is provided by the ground control system. Various equipment on the satellite is functioning, and whether the satellite has been running along the orbit, are to be carried out by ground equipment monitoring and control. Ground monitoring system is another important role is to maintain the satellite-GPS at the same time standard time system. This requires monitoring satellite ground station time, find the clock error. And then injected by the ground station to satellite, satellite navigation message to user devices. GPS satellite monitoring system consists of a primary control station on the ground, three into the station and
Five monitoring stations.
GPS signal receiver
GPS signal received machine of task is: can capture to by must satellite height due angle by select of moved measuring satellite of signal, and track these satellite of run, on by received to of GPS signal for transform, and zoom and processing, to measurement out GPS signal from satellite to receiver antenna of spread time, solutions translation out GPS satellite by sent of navigation message, real-time to calculation out measuring station of three dimensional location, location, even three dimensional speed and time.
Static positioning , GPS receiver in the process of capturing and tracking GPS satellites in a fixed constant, high-precision measurement of receiver GPS signal propagation time, using the known location of GPS satellites in orbit, resolving a receiver antenna location coordinates. Dynamic positioning is a running track of moving objects using a GPS receiver. GPS signal receivers located by moving objects called vectors (such as sailing ships, aircraft of the air and walking vehicles). GPS receiver antenna on the carriers in the process of tracking GPS satellite relative motion of the Earth, receiver GPS signal status real-time motion vector of measured parameters (three dimensional position and three dimensional velocity moments).
Receiver hardware and software , and GPS data post processing package , constitute a complete GPS user equipment. Structure of GPS receiver antenna unit and receiving unit two. -Geodetic receivers , two units were divided into two separate parts, observations on the antenna elements placed in the measuring station, near the reception unit at the station in the appropriate place, with a cable to connect the two into a complete machine. Also the antenna unit and receiving unit into a whole, observed when it is placed on the measuring site.
Battery power for GPS Receiver General. Two DC power both within and outside the machine. Set if the internal battery is intended to replace the outer batteries without interrupting continuous observation. In the process of using external battery, battery automatically charge inside the machine. After the shutdown, battery power the RAM memory inside the machine to prevent data loss. In recent years, domestic introduced many kind of GPS geodetic receivers. Various types of GPS geodetic receivers when used with precise relative positioning, its dual frequency receiver accuracy of up to 5mm+1PPM. D, single frequency receiver accuracy within a certain distance of up to 10mm+2PPM. D。 For differential positioning its up to sub-meter to centimeter-level accuracy. At present, various types of GPS receiver volume are smaller, growing light in weight, easy to field investigation. Compatible GPS and GLONASS global navigation and positioning system receiver has come out.
Many types of GPS satellite receiver, depending on the model is divided into of GEODESIC, all stations, regular-, handheld, integration-based-use into car-, ship-borne, airborne, satellite, missile type.
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Use of GPS navigation systems
GPS uses are wide-ranging, including ground positioning work needs to be done, can be reached using GPS.
“The investigation, detection of land”
For example: development of forest area, hillside violation checking work. Use GPS to navigate smoothly to variation of suspicious points, and query access to cadastral map, and other relevant information directly to facilitate the study.
“Navigation: vehicle, aviation, navigation”
For example: car satellite navigation systems, in United States Japan has become quite popular, is still in its infancy in China. In the foreseeable future, all the aircraft will use the standard GPS navigation device, at the time of aircraft taking off and landing, without relying on airport navigation equipment on the ground.
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GPS positioning system signal capture
In order to obtain the receiver position, base-frequency circuit has three main tasks: capture, tracking, and navigation. Signal capture for the purpose of determining the number of satellites and satellite available to the number. In order to decide which satellites do you want to search, often using satellite search algorithms to decide which satellite has a higher chance of occurrence. In completed signal capture of program zhihou, for master to of satellite its frequency and code phase estimation errors usually are little, however because frequency and the code phase of errors are non-will value, therefore receiver must using in signal capture in the by get of information for signals tracking, this program will further improved Qian in two item estimated value of accuracy, until estimated value relative stability down Hou, only will to code phase of information and the has demodulation of navigation information bit Yuan output to Hou end of navigation module.
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Global positioning system features
(1) clock;
(2) global coverage;
(3)-dimensional fixed speed timing precision;
(4), quick time efficient:
(5) widely used multi-purpose.
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Primary use of global positioning system
(1) land application, including vehicle navigation, emergency response, observations of atmospheric physics, geophysics, exploration, engineering, measurement, monitoring, monitoring of crustal movement , municipal planning, control, and;
(2), marine applications, including real-time scheduling best voyage route determination of ocean-going vessels, vessels and navigation, Ocean rescue, the study of Bao-, hydro-geological surveying and positioning, such as sea level fluctuation monitoring of offshore platform;
(3) aviation and space applications include aircraft navigation, airborne remote sensing attitude control and orbit determination of LEO satellites, missile guidance, aviation rescue and protection detection of manned spacecraft.
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GPS usage considerations
1. cannot rely star GPS search directly at home receiving United States GPS satellite signal work, need to see the sky in outdoor places to receive satellite signals, indoor cannot receive! 2. short battery use time all car GPS battery of continuous use time is not long, due to power the car a little smoke, designers do not see any opportunity to take a long time battery standby, standby battery only do, do not plug in power generally only ~1.5 hours 40 minutes of continuous use, a different model, with a different, there will be a large difference. Be noted that auto ignition moment of launch, a large current to start, have impact burning car filled with risk of fuse is best when the car starts, do not plug on cigarette car charger, started after the connection. 3. positioning allowed GPS positioning error in the normal plane of 10-20 meters, such as weather, United States GPS policy and many other factors, sometimes more. If the map indicates the location is not very accurate in the road, possibly because signal errors caused by bad cause delay, may also be occasional deviations of map data, there may be the road is very wide, so seems GPS seems stable offset surface. 4. not star or Star Search slow search encountered no stars or Star Search slow search situations do not worry, please change location change time to try it again. Do not use one or two times, or a day or two to decide to GPS is good or bad, due to different satellite status every day, probably the same place, signal full in the morning, but signal came close in the evening.
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Factors that affect reception of satellite signals
1, United States Department of Defense SA satellite signal interference. (Satellite signal under United States control, service may be interrupted occasionally signal) 2, weather factors. Such as sunspots, inclement weather (reduced signal strength, but does not affect the positioned) 3, electrical and electromagnetic interference, under the shelter (buildings, valleys, canyons, tunnels) 4, car windscreen window film, heat insulation, metal and paper components blanked. (Reduce the intensity of the signal, but does not affect the positioning) time is not displayed properly on the GPS satellite time date-time is designed to display, GPS satellite signal received is displayed properly when no signal is not normal, it is not commonly used in electronic form, you cannot resize cannot be saved. Total of 24 satellites GPS positioning satellite positioning system distributed in 6 tracks running, mutually 120 degrees between each track point allows GPS users at any time and place can receive satellite signals to be positioned. And are independent of the effects of weather (under the influence of terrain or building blanked, which is inside or on the bus more difficult to receive satellite signals
