Positioning system and control method thereof

• US 8,249,797 B2
• Filed: 08/30/2007
• Issued: 08/21/2012
• Est. Priority Date: 08/31/2006
• Status: Active Grant

• Current Assignee: MiTAC International Corporation (MiTAC Holdings Corp.)
• Original Assignee: MiTAC International Corporation (MiTAC Holdings Corp.)
• Inventors: Chuang, Chung-Hsien
• Primary Examiner(s): Tarcza, Thomas
• Assistant Examiner(s): MURSHED, NAGI M
• Application Number:
  US11/847,705
• Publication Number:
  US 20080059066A1
• Time in Patent Office: 1,818 Days
• Field of Search: 701/1, 701/200, 701/207, 701/213, 701/214, 701/300, 340/988, 340/995.1, 340/995.12, 340/995.25, 340/995.28, 342/350, 342/352, 342/357.01, 342/357.02, 342/357.06, 342/357.09, 342/357.1, 342/357.12, 342/357.13, 342/357.17, 342/358.08
• US Class Current: 701/213
• CPC Class Codes: G01S 19/37 Hardware or software details of the signal processing chain

Abstract

A positioning system includes a positioning module, an application program, a control program, a first transmission interface, a second transmission interface and a switch module. The positioning module is for providing positioning information. The application program is for controlling the positioning module to receive the positioning information from the positioning module. The control program is for controlling the positioning module to receive the positioning information from the positioning module when the application program is shutdown. The application program receives the positioning information through the first transmission interface. The control program receives the positioning information through the second transmission interface. The switch module can be selectively switched to decide whether the positioning module is controlled by the application program or the control program to receive the positioning information.

Claims

1. A positioning system, comprising:

a positioning module being in communication with at least one satellite, said positioning module receiving positioning information including ephemeris data;

a switch module coupled to said positioning module and having a pair of outputs for switching said positioning information between said pair of outputs;

a first transmission interface coupled to a first of said pair of outputs of said switch module;

a second transmission interface coupled to a second of said pair of outputs of said switch module; and

a central processor coupled to said first transmission interface for transmitting said positioning information received through said first transmission interface to a navigation application program responsive to said switch module coupling said positioning information to said first output, and said second transmission interface for transmitting said positioning information received from said second transmission interface to a control program responsive to said switch module coupling said positioning information to said second output;

wherein when the navigation application program is inactive, the control program controls the positioning module to receive the positioning information including the ephemeris data timely from the satellite through the positioning module;

wherein when the navigation application program is enabled, the control program is set into an inactive mode or an active mode, and the navigation application program receives the positioning information including the ephemeris data from the satellite through the positioning module, wherein said control program drives said positioning module into the inactive mode, if the intensity of a satellite signal received by said positioning module is lower than a predetermined value.

2. The positioning system of claim 1, wherein said positioning module is a global positioning system (GPS) module.

3. The positioning system of claim 1, wherein said first transmission interface and said second transmission interface are universal asynchronous receiver transmitter (UART) interfaces.

4. The positioning system of claim 1, wherein said switch module switches to said first state or said second state based on priority settings of said navigation application program and said control program.

5. The positioning system of claim 1, wherein said switch module switches to said first state or said second state based on a signal from a general-purpose I/O (GPIO) port of said central processor.

6. The positioning system of claim 1, wherein said control program is set into the inactive mode, if the power of said positioning system is low.

7. The positioning system of claim 1, wherein said control program is set into the inactive mode, if said positioning module has received sufficient positioning information.

8. The positioning system of claim 1, wherein said control program is set into the inactive mode, if the intensity of the satellite signal received by said positioning module is lower than the predetermined value.

9. A control method for a positioning system, comprising the steps of:

providing said positioning system having a navigation application and a control program;

starting said control program of said positioning system when said navigation program of said positioning system is inactive;

using said control program of said positioning system to control a positioning module, the positioning module being in communication with at least one satellite to receive positioning information therefrom, said positioning information including ephemeris data; and

setting said control program into an inactive mode or an active mode, responsive to said navigation application program being started so as to enable the positioning module to be in communication with the satellite for receiving said positioning information including said ephemeris data, wherein said control program is executed according to a procedure comprising the steps of;

(a) detecting whether or not a first serial port is in use, wherein said first serial port is provided for said navigation application program to access a positioning module;

if yes, then said control program is set into the inactive mode, or else go to Step (b);

(b) detecting whether or not there is sufficient power;

if yes, go to Step (c), or else said control program is set into the inactive mode;

(c) opening a second serial port which is provided for said control program to access said positioning module to receive said positioning information;

(d) detecting whether or not sufficient ephemeris data is received;

if yes, then close said second serial port to set said control program into the inactive mode, or else go to Step (e); and

(e) detecting whether or not the an intensity of a satellite signal received by said positioning module is lower than a predetermined value;

if yes, then close said second serial port to set said control program into the inactive mode.

10. A positioning system, comprising:

a central processor having a multi-threading architecture;

a positioning module being in communication with at least one satellite and receiving positioning information therefrom;

said positioning information including ephemeris data;

a serial port coupled to said positioning module;

a navigation application program controlling said positioning module through said a serial port; and

a control program controlling said positioning module through said serial port while said navigation application program is terminated;

wherein said central processor transmits said positioning information received through said multi-threading architecture to said navigation application program or said control program responsive to said multi-threading architecture coupling said positioning information to said serial port;

wherein when the navigation application program is inactive, the control program controls the positioning module to receive the positioning information including ephemeris data timely from the satellite through the positioning module;

wherein when the navigation application program is enabled, the control program is set into an inactive mode or an active mode, and the navigation application program receives the positioning information including the ephemeris data from the satellite through the positioning module, wherein said control program drives said positioning module into the inactive mode, if the intensity of a satellite signal received by said positioning module is lower than a predetermined value.