CN102621566A - Accurate positioning system for outdoor mobile robot - Google Patents

Abstract

The invention discloses an accurate positioning system for an outdoor mobile robot, which comprises a base station used for providing a charge interface for the mobile robot, wherein the base station is provided with a base station electronic control device which comprises a first power supply module used for providing a stable power supply, a first microcontroller used for concentrated processing, a charge module controlling the charge process, a first GPS module used for acquiring positioning data of the base station, and a first wireless serial communication module used for data transmission; and the mobile robot is provided with a robot electronic control device which is provided with a second power supply module used for providing a stable power supply, a second microcontroller used for concentrated processing, a second GPS module used for acquiring positioning data of the robot, a second wireless serial communication module used for data transmission, a human-computer interface used for state display and interface operations, a walking module used for walking drive, an environment sensing module used for detecting environment obstacles, and a task execution module related to specific tasks.

Description

Accurate positioning system of outdoor mobile robot

Technical Field

The invention relates to an accurate positioning system of an outdoor mobile robot, and belongs to the technical field of mobile robot positioning.

Background

At present, the robot technology is developed and applied rapidly. Industrial robots, such as welding robots, assembly robots, painting robots, etc., play an increasingly important role in industrial production sites, and have reached a satisfactory level in technology and application from automated production lines to unmanned workshops. But for service robots, it is still far behind the development of industrial robots, almost in the laboratory phase. It is feared that one of the robot-home dust collecting robots has gone into common home use and has formed an industrial scale. Even so, the technology of the household dust collection robot is not satisfactory, and the greatest difficulty is the positioning technology of the robot. Both the industry and academia are trying to overcome this problem.

Such a problem is also faced with outdoor mobile robots. Patent US6445983 discloses an autonomous navigation system, a robot system capable of switching between a visual navigation mode and a GPS navigation mode, and discloses a comprehensive application of a GPS system, a gyroscope system, and a visual system. Patent US7840352 discloses an automatic navigation system, disclosing and protecting a comprehensive system of GPS navigation, inertial navigation and visual navigation. In both patents, GPS location technology is used, but attempts are made to derive accurate location information from data output by the GPS device. However, the GPS positioning data contains unavoidable errors including systematic errors such as clock differences between the satellite and the receiver, ephemeris errors, ionospheric and tropospheric delay errors, etc., and random errors associated with the receiver itself. Therefore, the positioning accuracy of the GPS positioning data can only reach more than 10 meters based on the GPS positioning data alone, and for this reason, the automatic navigation system must include other positioning and navigation methods to compensate for the inaccuracy of the GPS positioning data.

Disclosure of Invention

The invention aims to solve the self-positioning problem of an outdoor mobile robot, and is based on the principle of differential GPS, GPS modules are respectively arranged on a base station and the mobile robot, and data fusion is carried out, so that the system positioning error is eliminated, and the purpose of accurate positioning is achieved.

The technical scheme adopted by the invention for solving the technical problems is as follows:

the accurate positioning system of the outdoor mobile robot comprises a base station for providing a charging interface for the mobile robot, wherein the base station is provided with a base station electronic control device, and the base station electronic control device comprises a first power supply module for providing a stable power supply, a first microcontroller for performing centralized processing and a charging module for controlling a charging process; the mobile robot set up the electronic control device of robot, the electronic control device of robot set up the second power module that provides stable power, carry out the second microcontroller of centralized processing, the human-computer interface who carries out state display and interface operation carries out walking drive's walking module, carries out the environmental perception module that environmental barrier detected and the task execution module relevant with concrete task, its characterized in that: the base station electronic control device also comprises a first GPS module for acquiring the positioning data of the base station and a first wireless serial communication module for data transmission; the robot electronic control device is also provided with a second GPS module for acquiring robot positioning data and a second wireless serial communication module for data transmission, and the second microcontroller is provided with a differential positioning algorithm.

The first GPS module is connected with the first microcontroller, and the first microcontroller is connected with the first wireless serial communication module; the first GPS module obtains positioning data of a base station and outputs the positioning data to the first microcontroller, and the first microcontroller sends the positioning data to the second wireless serial communication module through the first wireless serial communication module.

The second GPS module is connected with the second microcontroller, and the second microcontroller is connected with the second wireless serial communication module; the second GPS module obtains robot positioning data and outputs the robot positioning data to the second microcontroller; meanwhile, the second wireless serial communication module transmits the received base station positioning data to the second microcontroller.

The first wireless serial communication module is provided with the same parameters as the second wireless serial communication module and can carry out data transmission with the second wireless serial communication module.

The differential positioning algorithm comprises the following steps:

s1: when the mobile robot is at the position of the base station, the second microcontroller records the base station positioning data (E) obtained by the first GPS module through the second wireless serial communication module_b，N_b) And at the same time, the second microcontroller records the robot positioning data (E) obtained by the second GPS module_r，N_r)；

S2: the mobile robot leaves the base station to start working, the position measurement is carried out at intervals of unit time, and the second GPS module obtains real-time robot positioning data (e)_r，n_r) And sending the data to the second microcontroller, and simultaneously receiving the real-time base station positioning data (e) obtained by the first GPS module by the second microcontroller through the second wireless serial communication module_b，n_b)；

S3: the second microcontroller calculates the offset of the mobile robot relative to the base station: longitude offset Δ e ═ e (e)_r-E_r)-(e_b-E_b) Latitude deviation Δ n ═ n (n)_r-N_r)-(n_b-N_b)；

S4: the second microcontroller calculates the moving distance of the mobile robot relative to the base station: warp yarn moving distance Δ x ═ Δ e · R · cosN_bThe weft movement distance Δ y is Δ n · R, and R is the average radius of the equator of the earth.

Drawings

FIG. 1 is a system schematic;

FIG. 2 is a functional block diagram of the base station electronic control apparatus;

fig. 3 is a functional block diagram of the robot electronic control device.

Detailed Description

The invention is further described below with reference to the accompanying drawings.

Referring to fig. 1-3, the accurate positioning system of outdoor mobile robot includes a base station 14 for providing a charging interface for a mobile robot 15, the base station 14 is provided with a base station electronic control device, the base station electronic control device includes a first power module 1 for providing a stable power supply, a first microcontroller 2 for performing centralized processing and a charging module 5 for controlling a charging process, and further includes a first GPS module 3 for acquiring positioning data of the base station, and a first wireless serial communication module 4 for performing data transmission.

The mobile robot 15 set up the electronic control device of the robot, the electronic control device of the robot set up and provide the second power module 6 of the steady power, carry on the second microcontroller 7 of the centralized processing, carry on the human-computer interface 13 of state display and interface operation, walk the walking module 11 of the drive, carry on the environment perception module 12 that the environmental barrier measures and task execution module 10 relevant with concrete task, still set up and obtain the second GPS module 8 of the robot positioning data, carry on the second wireless serial communication module 9 of data transmission, the second microcontroller 7 set up the differential positioning algorithm. The task execution module 10, the walking module 11, the environment perception module 12 and the human-computer interface 13 are connected with the second micro controller 7 for centralized control.

The first wireless serial communication module 4 sets the same parameters as the second wireless serial communication module 9, and can perform data transmission with the second wireless serial communication module 9.

The first GPS module 3 is connected to the first microcontroller 2, and the first microcontroller 2 is connected to the first wireless serial communication module 4; the first GPS module 3 obtains base station positioning data and outputs the base station positioning data to the first microcontroller 2, the first microcontroller 2 sends the base station positioning data to the second wireless serial communication module 9 through the first wireless serial communication module 4, and the second wireless serial communication module 9 transmits the received base station positioning data to the second microcontroller 7.

The second GPS module 8 is connected to the second microcontroller 7, and the second microcontroller 7 is connected to the second wireless serial communication module 9; the second GPS module 8 obtains robot positioning data and outputs the robot positioning data to the second microcontroller 7.

And the second microcontroller 7 executes the differential positioning algorithm, and performs data fusion on the base station positioning data and the robot positioning data to obtain accurate positioning data. The differential positioning algorithm comprises the following steps:

s1: when the mobile robot 15 is located at the base station 14, the second microcontroller 7 records the base station positioning data (E) obtained by the first GPS module 3 through the second wireless serial communication module 9_b，N_b) Meanwhile, the second microcontroller 7 records the robot positioning data obtained by the second GPS module 8 (E)_r，N_r)；

S2: the mobile robot 15 leaves the base station 14 to start working, and performs position measurement every unit time, and the second GPS module 8 obtains real-time robot positioning data (e)_r，n_r) And sends it to the second microcontroller 7, and at the same time, the second microcontroller 7 receives the real-time base station positioning data (e) obtained by the first GPS module 3 through the second wireless serial communication module 9_b，n_b)；

S3: the second microcontroller 7 calculates the offset of the mobile robot 15 with respect to the base station 14: longitude offset Δ e ═ e (e)_r-E_r)-(e_b-E_b) Latitude deviation Δ n ═ n (n)_r-N_r)-(n_b-N_b)；

S4: the second microcontroller 7 calculates the moving distance of the mobile robot 15 relative to the base station 14: warp yarn moving distance Δ x ═ Δ e · R · cosN_bThe weft movement distance Δ y is Δ n · R, and R is the average radius of the equator of the earth.

Positioning data of base station for step S1 (E)_b，N_b) Which can be respectively expressed as:

base station longitude $E_b=E_b^T+d{E}_{\mathrm{sys},b},$

Base station latitude $N_b=N_b^T+d{N}_{\mathrm{sys},b}.$

Wherein,

is the true longitude and latitude, dE, of the base station 14_sys，b，dN_sys，bMeasuring longitude and latitude for said first GPS module 3The self random error of the first GPS module 3 has a small value, unmeasurable cause, which is not considered here.

And the robot positioning data of step S1 (E)_r，N_r) Respectively is as follows:

base station longitude $E_r=E_r^T+d{E}_{\mathrm{sys},r}$

Base station latitude $N_r=N_r^T+d{N}_{\mathrm{sys},r}$

Wherein,

is the true longitude and latitude of the base station 14, andsame, dE_sys，r， dN_sys，rThe systematic errors of longitude and latitude are measured for the second GPS module 8, while the random error of the second GPS module 8 itself has a small value, which is not a measurable cause, and is not considered here.

For the real-time base station positioning data in step S2 (e)_b，n_b) Respectively is as follows:

base station longitude $e_b=E_b^T+d{e}_{\mathrm{sys},b}$

Base station latitude $n_b=N_b^T+d{n}_{\mathrm{sys},b}.$

Wherein, de_sys，b，dn_sys，bReal-time system errors in longitude and latitude are measured for said first GPS module 3.

And the real-time robot positioning data of step S2 (e)_r，n_r) Respectively is as follows:

base station longitude $e_r=e_r^T+d{e}_{\mathrm{sys},r}$

Base station latitude $n_r=n_r^T+d{n}_{\mathrm{sys},r}.$

Wherein,

is the true longitude and latitude of the position of the mobile robot 15, d_esys，r，dn_sys，rReal-time system errors in longitude and latitude are measured for the second GPS module 8.

In step S3, the offset of the mobile robot 15 from the base station 14 is calculated:

longitude offset <math><mrow> <mi>&Delta;e</mi> <mo>=</mo> <mrow> <mo>(</mo> <msub> <mi>e</mi> <mi>r</mi> </msub> <mo>-</mo> <msub> <mi>E</mi> <mi>r</mi> </msub> <mo>)</mo> </mrow> <mo>-</mo> <mrow> <mo>(</mo> <msub> <mi>e</mi> <mi>b</mi> </msub> <mo>-</mo> <msub> <mi>E</mi> <mi>b</mi> </msub> <mo>)</mo> </mrow> </mrow></math>

$=(e_r^T+d{e}_{\mathrm{sys},r}-E_r^T-d{E}_{\mathrm{sys},r})-(E_b^T+d{e}_{\mathrm{sys},b}-E_b^T-d{E}_{\mathrm{sys},b})$

$=(e_r^T-E_r^T)+(d{e}_{\mathrm{sys},r}-d{E}_{\mathrm{sys},r})-(d{e}_{\mathrm{sys},b}-d{E}_{\mathrm{sys},b})$

$=(e_r^T-E_r^T)+(d{e}_{\mathrm{sys},r}-d{e}_{\mathrm{sys},b})-(d{E}_{\mathrm{sys},r}-d{E}_{\mathrm{sys},b})$

Latitude deviation <math><mrow> <mi>&Delta;n</mi> <mo>=</mo> <mrow> <mo>(</mo> <msub> <mi>n</mi> <mi>r</mi> </msub> <mo>-</mo> <msub> <mi>N</mi> <mi>r</mi> </msub> <mo>)</mo> </mrow> <mo>-</mo> <mrow> <mo>(</mo> <msub> <mi>n</mi> <mi>b</mi> </msub> <mo>-</mo> <msub> <mi>N</mi> <mi>b</mi> </msub> <mo>)</mo> </mrow> </mrow></math>

$=(n_r^T+d{n}_{\mathrm{sys},r}-N_r^T-d{N}_{\mathrm{sys},r})-(N_b^T+d{n}_{\mathrm{sys},b}-N_b^T-d{N}_{\mathrm{sys},b})$

$=(n_r^T-N_r^T)+(d{n}_{\mathrm{sys},r}-d{N}_{\mathrm{sys},r})-(d{n}_{\mathrm{sys},b}-d{N}_{\mathrm{sys},b})$

$=(n_r^T-N_r^T)+(d{n}_{\mathrm{sys},r}-d{n}_{\mathrm{sys},b})-(d{N}_{\mathrm{sys},r}-d{N}_{\mathrm{sys},b})$

Since the system errors of the first GPS module 3 and the second GPS module 8 are the same at the same point in time, therefore,

de_sys，r＝de_sys，b，dE_sys，r＝dE_sys，b，dn_sys，r＝dn_sys，b，dN_sys，r＝dN_sys，b。

to obtain finally <math><mrow> <mi>&Delta;e</mi> <mrow> <mo>(</mo> <msub> <mi>e</mi> <mi>r</mi> </msub> <mo>-</mo> <msub> <mi>E</mi> <mi>r</mi> </msub> <mo>)</mo> </mrow> <mo>-</mo> <mrow> <mo>(</mo> <msub> <mi>e</mi> <mi>b</mi> </msub> <mo>-</mo> <msub> <mi>E</mi> <mi>b</mi> </msub> <mo>)</mo> </mrow> </mrow></math>

$=e_r^T-E_r^T$ (or

<math><mrow> <mi>&Delta;n</mi> <mo>=</mo> <mrow> <mo>(</mo> <msub> <mi>n</mi> <mi>r</mi> </msub> <mo>-</mo> <msub> <mi>N</mi> <mi>r</mi> </msub> <mo>)</mo> </mrow> <mo>-</mo> <mrow> <mo>(</mo> <msub> <mi>n</mi> <mi>b</mi> </msub> <mo>-</mo> <msub> <mi>N</mi> <mi>b</mi> </msub> <mo>)</mo> </mrow> </mrow></math>

$=n_r^T-N_r^T$ (or

The moving distance of the mobile robot 15 relative to the base station 14 can be obtained in step S4. Wherein the latitude data in the longitude moving distance delta x adopts the latitude N obtained by the base station_bLatitude N_bInherently with systematic errors, but in said step S4 with R. cosN_bUsed as a constant, has a limited effect on accuracy.

In conclusion, the real moving distance of the mobile robot obtained by the differential positioning algorithm removes the system error in measurement, only retains a small part of random errors, and provides an accurate solution for positioning and navigation of the outdoor mobile robot.

Claims (5)

1. The accurate positioning system of the outdoor mobile robot comprises a base station for providing a charging interface for the mobile robot, wherein the base station is provided with a base station electronic control device, and the base station electronic control device comprises a first power supply module for providing a stable power supply, a first microcontroller for performing centralized processing and a charging module for controlling a charging process; the mobile robot set up the electronic control device of robot, the electronic control device of robot set up the second power module that provides stable power, carry out the second microcontroller of centralized processing, the human-computer interface who carries out state display and interface operation carries out walking drive's walking module, carries out the environmental perception module that environmental barrier detected and the task execution module relevant with concrete task, its characterized in that: the base station electronic control device also comprises a first GPS module for acquiring the positioning data of the base station and a first wireless serial communication module for data transmission; the robot electronic control device is also provided with a second GPS module for acquiring robot positioning data and a second wireless serial communication module for data transmission, and the second microcontroller is provided with a differential positioning algorithm.

2. The accurate positioning system of an outdoor mobile robot of claim 1, characterized in that: the first GPS module is connected with the first microcontroller, and the first microcontroller is connected with the first wireless serial communication module; the first GPS module obtains positioning data of a base station and outputs the positioning data to the first microcontroller, and the first microcontroller sends the positioning data to the second wireless serial communication module through the first wireless serial communication module.

3. The accurate positioning system of an outdoor mobile robot of claim 1, characterized in that: the second GPS module is connected with the second microcontroller, and the second microcontroller is connected with the second wireless serial communication module; the second GPS module obtains robot positioning data and outputs the robot positioning data to the second microcontroller; meanwhile, the second wireless serial communication module transmits the received base station positioning data to the second microcontroller.

4. The accurate positioning system of an outdoor mobile robot according to claim 2 or 3, characterized in that: the first wireless serial communication module is provided with the same parameters as the second wireless serial communication module and can carry out data transmission with the second wireless serial communication module.

5. The accurate positioning system of an outdoor mobile robot of claim 1, characterized in that: the differential positioning algorithm comprises the following steps:

s1: when the mobile robot is at the position of the base station, the second microcontroller records the base station positioning data (E) obtained by the first GPS module through the second wireless serial communication module_b，N_b) And at the same time, the second microcontroller records the robot positioning data (E) obtained by the second GPS module_r，N_r)；

S2: the mobile robot leaves the base station to start working, the position measurement is carried out at intervals of unit time, and the second GPS module obtains real-time robot positioning data (e)_r，n_r) And sending the data to the second microcontroller, and simultaneously receiving the real-time base station positioning data (e) obtained by the first GPS module by the second microcontroller through the second wireless serial communication module_b，n_b)；

S3: the second microcontroller calculates the offset of the mobile robot relative to the base station: longitude offset Δ e ═ e (e)_r-E_r)-(e_b-E_b) Latitude deviation Δ n ═ n (n)_r-N_r)-(n_b-N_b)；

S4: the second microcontroller calculates the moving distance of the mobile robot relative to the base station: warp yarn moving distance Δ x ═ Δ e · R · cosN_bThe weft movement distance Δ y is Δ n · R, and R is the average radius of the equator of the earth.

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