Positioning system and method thereof

Abstract

The invention provides a positioning system. In one embodiment, the positioning system comprises a Global Navigation Satellite System (GNSS) module, a dead reckoning module, a Geographic Information System (GIS) module, and an calculating module. The GNSS module generates a first positioning data according to satellite communication. The dead reckoning module estimates a second positioning data according to a sensor's measurement data, the first positioning data, and a feedback positioning data of a previous epoch. The GIS module fits the first positioning data to a map to generate a third positioning data taken as a final output of the positioning system. The calculating module integrates the third positioning data and the second positioning data according to predetermined weights to obtain the feedback positioning data of a current epoch, which is recursively fed back to the dead reckoning module for a next estimation.

1 . A positioning system, comprising:
 a Global Navigation Satellite System (GNSS) module, generating a first positioning data according to satellite communication;   a dead reckoning module, estimating a second positioning data according to a measurement data, the first positioning data, and a feedback positioning data of a previous epoch;   a Geographic Information System (GIS) module, fitting the first positioning data to a map to generate a third positioning data taken as a final output of the positioning system; and   a calculating module, deriving the feedback positioning data of a current epoch from the third positioning data and the second positioning data according to predetermined weights, wherein the feedback positioning data is recursively fed back to the dead reckoning module for a next estimation.   
     
     
         2 . The positioning system as claimed in  claim 1 , wherein the GNSS module further comprises:
 a GNSS baseband processor, generating a GNSS measurement data according to satellite communication; and   a first Kalman filter, coupled to the GNSS baseband processor, generating the first positioning data according to the GNSS measurement data.   
     
     
         3 . The positioning system as claimed in  claim 1 , wherein the dead reckoning module further comprises:
 a dead reckoning sensor, generating the measurement data of the current epoch; and   a second Kalman filter, coupled to the dead reckoning sensor, comprising:
 a time propagation module, estimating a fourth positioning data of the current epoch according to the feedback positioning data of the previous epoch and the measurement data of the current epoch; and 
 a measurement update module, estimating the second positioning data of the current epoch according to the fourth positioning data of the current epoch and the first positioning data of the current epoch. 
   
     
     
         4 . The positioning system as claimed in  claim 3 , wherein the GIS module generates the third positioning data according to the fourth positioning data and the calculating module directly outputs the third positioning data as the feedback positioning data when the first positioning data is unavailable. 
     
     
         5 . The positioning system as claimed in  claim 3 , wherein the GNSS module comprises a first Kalman filter generating the first positioning data according to the fourth positioning data and a GNSS measurement data generated by a GNSS baseband processor. 
     
     
         6 . The positioning system as claimed in  claim 5 , wherein the first Kalman filter generates the first positioning data according to only the fourth positioning data and the calculating module directly outputs the third positioning data as the feedback positioning data when the GNSS measurement data is unavailable. 
     
     
         7 . The positioning system as claimed in  claim 1 , wherein the first positioning data comprises a position data, a velocity data, and a time data. 
     
     
         8 . The positioning system as claimed in  claim 3 , wherein the dead reckoning sensor is the integration of at least a linear movement sensor measuring a linear movement to generate the measurement data and an angular movement sensor measuring an angular movement to generate the measurement data. 
     
     
         9 . A positioning system, comprising:
 a Global Navigation Satellite System (GNSS) module, generating a first positioning data according to satellite communication;   a dead reckoning module, estimating a second positioning data according to a measurement data, the first positioning data, and a feedback positioning data of a previous epoch;   a calculating module, deriving a third positioning data from the first positioning data and the second positioning data according to predetermined weights; and   a GIS module, fitting the third positioning data to a map to generate the feedback positioning data of a current epoch, which is taken as a final output of the positioning system and recursively fed back to the dead reckoning module for a next estimation.   
     
     
         10 . The positioning system as claimed in  claim 9 , wherein the GNSS module further comprises:
 a GNSS baseband processor, generating a GNSS measurement data according to satellite communication; and   a first Kalman filter, coupled to the GNSS baseband processor, generating the first positioning data according to the GNSS measurement data.   
     
     
         11 . The positioning system as claimed in  claim 9 , wherein the dead reckoning module further comprises:
 a dead reckoning sensor, generating the measurement data of the current epoch; and   a second Kalman filter, coupled to the dead reckoning sensor, comprising:
 a time propagation module, estimating a fourth positioning data of the current epoch according to the feedback positioning data of the previous epoch and the measurement data of the current epoch; and 
 a measurement update module, estimating the second positioning data of the current epoch according to the fourth positioning data of the current epoch and the first positioning data of the current epoch. 
   
     
     
         12 . The positioning system as claimed in  claim 11 , wherein the GIS module generates the feedback positioning data according to the fourth positioning data when the first positioning data is unavailable and the third positioning data is erroneous. 
     
     
         13 . The positioning system as claimed in  claim 11 , wherein the GNSS module comprises a first Kalman filter generating the first positioning data according to the fourth positioning data and a GNSS measurement data generated by a GNSS baseband processor. 
     
     
         14 . The positioning system as claimed in  claim 13 , wherein the first Kalman filter generates the first positioning data according to only the fourth positioning data and the calculating module directly outputs the first positioning data as the third positioning data when the GNSS measurement data is unavailable. 
     
     
         15 . The positioning system as claimed in  claim 9 , wherein the first positioning data comprises a position data, a velocity data, and a time data. 
     
     
         16 . The positioning system as claimed in  claim 11 , wherein the dead reckoning sensor is the integration of at least a linear movement sensor measuring a linear movement to generate the measurement data and an angular movement sensor measuring an angular movement to generate the measurement data. 
     
     
         17 . A positioning system, comprising:
 a Global Navigation Satellite System (GNSS) baseband processor, generating a GNSS measurement data according to satellite communication;   a dead reckoning sensor, generating a measurement data;   a Kalman filter, estimating a first positioning data according to the sensor's measurement data, the GNSS measurement data, and a second positioning data of a previous epoch; and   a Geographic Information System (GIS) module, fitting the first positioning data to a map to generate the second positioning data of a current epoch, which is taken as a final output of the positioning system and recursively fed back to the Kalman filter for a next estimation.   
     
     
         18 . The positioning system as claimed in  claim 17 , wherein the Kalman filter further comprises:
 a time propagation module, estimating a third positioning data of the current epoch according to the second positioning data of the previous epoch, and the measurement data of the current epoch; and   a measurement update module, estimating the second positioning data of the current epoch according to the third positioning data of the current epoch and the GNSS measurement data of the current epoch.   
     
     
         19 . The positioning system as claimed in  claim 18 , wherein the GIS module generates the second positioning data according to the third positioning data when the GNSS measurement data is unavailable. 
     
     
         20 . The positioning system as claimed in  claim 17 , wherein the GNSS measurement data comprises a position data, a velocity data, a attitude data, and a time data. 
     
     
         21 . The positioning system as claimed in  claim 17 , wherein the dead reckoning sensor is the integration of at least a linear movement sensor measuring a linear movement to generate the measurement data and an angular measurement sensor measuring an angular movement to generate the movement data. 
     
     
         22 . A method of positioning, comprising:
 generating a GNSS measurement data with a Global Navigation Satellite System (GNSS) baseband processor according to satellite communication;   generating a measurement data with a dead reckoning sensor;   deriving a first positioning data from the sensor's measurement data, the GNSS measurement data, and a feedback positioning data of a previous epoch when the first positioning data is available;   fitting the first positioning data to a map with a geographic information system to generate a second positioning data of a current epoch, which is taken as a final output of the positioning system; and   recursively feeding the second positioning data back as the feedback positioning data for derivation of the first positioning data of a next epoch.   
     
     
         23 . The method as claimed in  claim 22 , further comprising deriving the first positioning data from the sensor's measurement data and the feedback positioning data of the previous epoch when the first positioning data is unavailable. 
     
     
         24 . The method as claimed in  claim 22 , wherein the derivation of the first positioning data is implemented with a single Kalman filter. 
     
     
         25 . The method as claimed in  claim 22 , wherein the derivation of the first positioning data comprising:
 estimating a third positioning data according to the GNSS measurement data with a first Kalman filter;   estimating a fourth positioning data according to the sensor's measurement data and the feedback positioning data of the previous epoch with a second Kalman filter; and   deriving the first positioning data from the third positioning data and the fourth positioning data according to predetermined weights.