Positioning method, device and system

A positioning method, comprising:

• 101. obtaining, by a positioning server, location service information of APs in a set of APs to be measured, wherein the set of APs to be measured comprises at least three APs, and the location service information comprises an identifier of an AP, a measured received signal strength indicator RSSI value, and a measured signal propagation duration value;
• 102. obtaining, by the positioning server, their respective calculated RSSI values of all APs in the set of APs to be measured at all coordinates in a preset propagation model signal graph according to the preset propagation model signal graph, calculating and comparing quadratic sums of differences between the calculated RSSI values of all APs in the set of APs to be measured at all coordinates and the three corresponding measured RSSI values of the APs, and using the coordinate corresponding to a minimum quadratic sum as a first coordinate of the terminal;
• 103. selecting, by the positioning server according to a preset rule, any unmeasured AP in the set of APs to be measured, and calculating a calculated signal propagation duration value of propagation from the unmeasured AP to the first coordinate in the propagation model signal graph according to a distance from the unmeasured AP to the first coordinate in the preset propagation model signal graph;
• 104. determining that signals of the unmeasured AP are not affected by reflection if an absolute value of a difference between a calculated signal propagation duration value of the unmeasured AP and the measured signal propagation duration value of the unmeasured AP is not greater than a preset threshold, and determining, by the positioning server according to the identifiers of the APs, whether all APs in the set of APs to be measured have been measured;
• 105. performing 103 and 104 repeatedly if any AP in the set of APs to be measured has still not been measured;
• and
• 106. using the first coordinate as a location coordinate of the terminal if all APs in the set of APs to be measured have been measured, thereby positioning the terminal.

A positioning device, comprising:

• a first obtaining unit, configured to obtain location service information of APs in a set of APs to be measured, wherein the set of APs to be measured comprises at least three APs, and the location service information comprises an identifier of an AP, a measured received signal strength indicator RSSI value, and signal propagation time information;
• a calculating unit, configured to select three APs to be measured in the set of APs to be measured according to a preset rule, and calculate a first coordinate of a terminal according to signal propagation time information of the three APs to be measured;
• a second obtaining unit, configured to obtain a calculated RSSI value of any unmeasured AP in the three APs to be measured at the first coordinate according to a preset propagation model signal graph;
• a first determining unit, configured to determine whether the calculated RSSI value of the unmeasured AP is smaller than a difference between a measured RSSI value of the unmeasured AP and a preset threshold, so as to determine whether signals of the unmeasured AP are not affected by reflection;
• a second determining unit, configured to determine, according to the identifiers of the APs, whether all the three APs to be measured have been measured if the first determining unit determines that the calculated RSSI value of the unmeasured AP is not smaller than the difference between the measured RSSI value of the unmeasured AP and the preset threshold and that the signals of the unmeasured AP are not affected by reflection;
• and
• a positioning unit, configured to determine the first coordinate as a location coordinate of the terminal if the second determining unit determines that all the three APs to be measured have been measured, thereby positioning the terminal.

A positioning device, comprising:

• an obtaining unit, configured to obtain location service information of APs in a set of APs to be measured, wherein the set of APs to be measured comprises at least three APs, and the location service information comprises an identifier of an AP, a measured received signal strength indicator RSSI value, and a measured signal propagation duration value;
• a calculating and comparing unit, configured to obtain their respective calculated RSSI values of all APs in the set of APs to be measured at all coordinates in a preset propagation model signal graph according to the preset propagation model signal graph, calculate and compare quadratic sums of differences between the calculated RSSI values of all APs in the set of APs to be measured at all coordinates and the three corresponding measured RSSI values of the APs, and use the coordinate corresponding to a minimum quadratic sum as a first coordinate of the terminal;
• a calculating unit, configured to select, according to a preset rule, any unmeasured AP in the set of APs to be measured, and calculate a calculated signal propagation duration value of propagating a signal from the unmeasured AP to the first coordinate in the propagation model signal graph according to a distance from the unmeasured AP to the first coordinate in the preset propagation model signal graph;
• a first determining unit, configured to determine whether an absolute value of a difference between the calculated signal propagation duration value of the unmeasured AP and the measured signal propagation duration value of the unmeasured AP is greater than a preset threshold, so as to determine whether signals of the unmeasured AP are not affected by reflection;
• a second determining unit, configured to determine, according to the identifiers of the APs, whether all the APs in the set of APs to be measured have been measured if the first determining unit determines that the absolute value of the difference between the calculated signal propagation duration value of the unmeasured AP and the measured signal propagation duration value of the unmeasured AP is not greater than the preset threshold and that the signals of the unmeasured AP are not affected by reflection;
• and
• a positioning unit, configured to determine the first coordinate as a location coordinate of the terminal if the second determining unit determines that all the APs in the set of APs to be measured have been measured, thereby positioning the terminal.

A positioning system, comprising at least three APs and a positioning device, wherein

• the positioning device is configured to obtain location service information of APs in a set of APs to be measured, wherein the set of APs to be measured comprises at least three APs, and the location service information comprises an identifier of an AP, a measured received signal strength indicator RSSI value, and signal propagation time information;
• select three APs to be measured in the set of APs to be measured according to a preset rule, and calculate a first coordinate of a terminal according to signal propagation time information of the three APs to be measured;
• obtain a calculated RSSI value of any unmeasured AP in the three APs to be measured at the first coordinate according to a preset propagation model signal graph;
• determine whether the calculated RSSI value of the unmeasured AP is smaller than a difference between a measured RSSI value of the unmeasured AP and a preset threshold, so as to determine whether signals of the unmeasured AP are not affected by reflection;
• determine, according to the identifiers of the APs, whether all the three APs to be measured have been measured if the first determining unit determines that the calculated RSSI value of the unmeasured AP is not smaller than the difference between the measured RSSI value of the unmeasured AP and the preset threshold and that the signals of the unmeasured AP are not affected by reflection;
• and determine the first coordinate as a location coordinate of the terminal if the second determining unit determines that all the three APs to be measured have been measured, thereby positioning the terminal;
• or
• the positioning device is configured to obtain location service information of APs in a set of APs to be measured, wherein the set of APs to be measured comprises at least three APs, and the location service information comprises an identifier of an AP, a measured received signal strength indicator RSSI value, and a measured signal propagation duration value;
• obtain their respective calculated RSSI values of all APs in the set of APs to be measured at all coordinates in a preset propagation model signal graph according to the preset propagation model signal graph, calculate and compare quadratic sums of differences between the calculated RSSI values of all APs in the set of APs to be measured at all coordinates and the three corresponding measured RSSI values of the APs, and use the coordinate corresponding to a minimum quadratic sum as a first coordinate of the terminal;
• select, according to a preset rule, any unmeasured AP in the set of APs to be measured, and calculate a calculated signal propagation duration value of propagating a signal from the unmeasured AP to the first coordinate in the propagation model signal graph according to a distance from the unmeasured AP to the first coordinate in the preset propagation model signal graph;
• determine whether an absolute value of a difference between the calculated signal propagation duration value of the unmeasured AP and the measured signal propagation duration value of the unmeasured AP is greater than a preset threshold, so as to determine whether signals of the unmeasured AP are not affected by reflection;
• determine, according to the identifiers of the APs, whether all the APs in the set of APs to be measured have been measured if the first determining unit determines that the absolute value of the difference between the calculated signal propagation duration value of the unmeasured AP and the measured signal propagation duration value of the unmeasured AP is not greater than the preset threshold and that the signals of the unmeasured AP are not affected by reflection;
• and determine the first coordinate as a location coordinate of the terminal if the second determining unit determines that all the APs in the set of APs to be measured have been measured, thereby positioning the terminal.