CN206378597U - A kind of low-cost and high-precision alignment system - Google Patents

Abstract

The utility model discloses a low-cost high-precision positioning system, which is composed of a single-frequency receiver, a GPRS module and a processor control module. The single-frequency receiver acts as a user receiver to obtain satellite data; the GPRS module communicates with the base station to obtain base station data; the processor control module decodes the data sent by the single-frequency receiver and GPRS module to obtain ephemeris data and single-frequency reception Observation data of the computer, coordinate data of the base station and observation data of the base station; then calculate the offset according to these data; finally obtain the coordinates of the user according to the offset and the coordinates of the base station. The utility model adopts a single-frequency receiver to realize RTK technology; first, the price of the single-frequency receiver is low, only one tenth of that of the dual-frequency receiver, and can be widely used in the market; secondly, the power consumption of the single-frequency receiver is low, and it is suitable for embedding type equipment; the utility model has the characteristics of small size, light weight and portability, and can be installed on the drone.

Description

A low-cost high-precision positioning system

technical field

The utility model relates to the technical field of positioning, in particular to a low-cost and high-precision positioning system.

Background technique

With the advent of the Internet of Things era, high-precision positioning equipment has received more and more attention from the market. UAV remote sensing photogrammetry, UAV express delivery, driver's license test, and real-time statistics of crowd density all require high-precision positioning equipment. High-precision positioning equipment basically relies on RTK technology. RTK (Real-time kinematic) carrier phase difference technology is a difference method for real-time processing of carrier phase observations of two measurement stations, and sends the carrier phase collected by the reference station to the user receiver for difference calculation and coordinates. Existing equipment using RTK technology relies on dual-frequency receivers in hardware. However, the dual-frequency receiver has the following problems: first, the dual-frequency receiver is expensive, and it is difficult for ordinary users to afford it, so it is not suitable for promotion; secondly, the dual-frequency receiver consumes a lot of power and requires high battery power; The receiver is bulky and not easy to carry.

Utility model content

The technical problem to be solved by the utility model is that the existing equipment using RTK technology needs to rely on a dual-frequency receiver to provide a low-cost high-precision positioning system.

In order to solve the above problems, the utility model is achieved through the following technical solutions:

A low-cost high-precision positioning system, including a single-frequency receiver, a GPRS module, a processor control module and a power supply module; the single-frequency receiver is used as a user receiver to obtain satellite data; the GPRS module communicates with a base station to obtain base station data; processing The controller control module decodes the data sent by the single-frequency receiver and the GPRS module, and obtains the ephemeris data, the observation value data of the single-frequency receiver, the coordinate data of the base station, and the observation value data of the base station; and then calculates the offset according to these data After that, the coordinates of the user are obtained according to the offset and the coordinates of the base station; the power module supplies power for the single-frequency receiver, the GPRS module and the processor control module.

Especially, the single-frequency receiver communicates with the satellite through the antenna, and the single-frequency receiver is connected with the processor control module through the USB interface.

In particular, the GPRS module communicates with the base station through the antenna, and the GPRS module is connected with the processor control module through the RS232 interface.

The utility model constructs a positioning system with a single-frequency receiver, a GPRS module and a processor control module as the core. The satellite data is obtained through the single-frequency receiver, and the base station data is obtained through the GPRS module. The processor control module is based on the satellite data and the base station data. Perform differential processing, and obtain the user's location information accordingly.

Compared with the existing technology, single-frequency receivers are used to realize RTK technology; firstly, single-frequency receivers are cheap, only one-tenth of dual-frequency receivers, and can be widely used in the market; secondly, single-frequency receivers have low power consumption , suitable for embedded devices; the utility model has the characteristics of small size, light weight and portability, and can be installed on a drone.

Description of drawings

Figure 1 is a block diagram of a low-cost high-precision positioning system.

detailed description

The preferred embodiments of the present invention will be further described below in conjunction with the accompanying drawings. It should be emphasized that the present invention is not limited to the following embodiments.

A low-cost high-precision positioning system, as shown in Figure 1, consists of a single-frequency receiver, GPRS module, processor control module and power supply module. The single-frequency receiver communicates with the satellite through an antenna, and the single-frequency receiver is connected with the processor control module through a USB interface. The GPRS module communicates with the base station through another antenna, and the GPRS module is connected with the processor control module through the RS232 interface.

The single-frequency receiver is used as a user receiver to obtain satellite data. The single-frequency receiver receives data from the L1 frequency band of GPS satellites and performs corresponding calculations, and can output GPS satellite pseudo-range observation values, carrier observation values, and GPS satellite ephemeris data in the L1 frequency band. These data are sent in a fixed format.

The GPRS module is used to communicate with the base station and obtain the data of the base station. The GPRS module obtains the base station data from the base station according to information such as IP address, port number, account number and password. The base station data includes the coordinates of the base station receiver, as well as the pseudo-range observation value and carrier observation value of the base station in the L1 frequency band. Base station data has a fixed format called RTCM format.

The processor control module processes satellite data and base station data, and outputs positioning results. In this embodiment, the core of the processor control module is an ARM processor.

The processor control module receives the data sent by the single frequency receiver and the GPRS module. First decode the data of the receiver, run the decoding module, and extract the corresponding value. Then decode the base station data, run the RTCM decoding module, and resolve to the corresponding value of the base station. Run the satellite selection program to delete satellite data with large observation error, such as satellites with low altitude angle and low signal-to-noise ratio. Bring the data of the remaining stars into the difference program to obtain the offset of the user receiver relative to the base station. There is a large error in this offset, so a high-precision algorithm module is introduced to improve the accuracy of the offset. Add the offset to the base station coordinates to obtain high-precision coordinates.

The data transmitted by the single frequency receiver is divided into 2 categories. The first type is called observation value, which consists of current time, pseudorange value ρ and L1 frequency band carrier value constitute. The pseudo-range value means that the receiver calculates the distance from the satellite to the receiver by reading the data sent by the satellite. However, due to some problems in the data sent by the satellite, the measured distance value has a large error. The carrier value refers to the transmission of satellite data through electromagnetic waves. Since the frequency of electromagnetic waves is known, the circumference of the carrier is determined. The receiver can calculate the number of carrier cycles from the satellite to the receiver, and then know the distance from the satellite to the receiver. Due to the short wavelength and the precise number of cycles, the carrier observation value has high precision, but there is an integer ambiguity problem. The second type is called satellite ephemeris data. The satellite moves in real time in space. The satellite does not broadcast the real-time orbit coordinates of the satellite, but sends a set of orbit parameters. The user can calculate the current coordinates of the satellite according to the current moment.

The data transmitted by the base station is also divided into two categories. The first category is the observation value, which is the current time, the pseudo-range observation value and the carrier observation value from the base station receiver to the GPS satellite. The second category is the coordinates of the base station, which are precise coordinates with extremely high precision.

The power supply module supplies power to the single frequency receiver, GPRS module and processor control module. In this embodiment, the power supply module is connected to a DC power supply, and filters the input DC power supply to stabilize the power supply voltage to supply power to the above three modules.

The traditional high-precision positioning system needs to use a dual-frequency receiver to achieve high-precision positioning through the difference between two satellite signals. However, the high-precision positioning system of the present invention uses a combination of a single-frequency receiver and a GPRS module to achieve high-precision positioning through satellite data and The base station data is differentiated to achieve high-precision positioning. The process of differential processing of satellite data and base station data in the processor control module to obtain high-precision positioning results is similar to the process of differential processing of two satellite data to obtain high-precision positioning results. The satellite signal was replaced by a base station signal. Since the accuracy of the base station signal is far greater than that of the satellite signal, the positioning result obtained by the utility model has a higher accuracy than that achieved by the dual-frequency receiver. In addition, the invention also has the characteristics of low price, low power consumption and easy system embedding.

Claims (3)

1. A low-cost high-precision positioning system is characterized in that it comprises a single-frequency receiver, a GPRS module, a processor control module and a power supply module; The single-frequency receiver communicates with the satellite, and the output end of the single-frequency receiver is connected to the input end of the processor control module; the single-frequency receiver is used as a user receiver to obtain satellite data; The GPRS module communicates with the base station, the output end of the GPRS module is connected to the input end of the processor control module, and the GPRS module obtains the base station data; The processor control module is connected to the single-frequency receiver and the GPRS module at the same time; the processor control module performs differential processing on the satellite data sent by the single-frequency receiver and the base station data sent by the GPRS module to obtain the user's position coordinates; Power supply module The power supply module is connected with the single-frequency receiver, the GPRS module and the processor control module, and the power supply module supplies power for the single-frequency receiver, the GPRS module and the processor control module. 2. A low-cost high-precision positioning system according to claim 1, wherein the single-frequency receiver communicates with the satellite through an antenna, and the single-frequency receiver is connected with the processor control module through a USB interface. 3. a kind of low-cost high-precision positioning system according to claim 1 is characterized in that, GPRS module communicates with base station by antenna, and GPRS module is connected with processor control module by RS232 interface.