Method for controlling a navigation device and navigation device implementing the same

• US 6,694,276 B2
• Filed: 06/26/2001
• Issued: 02/17/2004
• Est. Priority Date: 07/04/2000
• Status: Expired due to Fees

• Current Assignee: Asulab SA (The Swatch Group AG)
• Original Assignee: Asulab SA (The Swatch Group AG)
• Inventors: Kim, Thien, Farine, Pierre-André, Piccini, Fanel
• Primary Examiner(s): Barlow, John
• Assistant Examiner(s): LE, JOHN H
• Application Number:
  US09/892,421
• Publication Number:
  US 20020004708A1
• Time in Patent Office: 966 Days
• Field of Search: 702/85, 702/94, 702/95, 702/96, 702/97, 702/149, 702/150, 702/158, 701/119, 701/120, 701/121, 701/122, 701/213, 701/214, 701/216, 701/217, 324/357.12, 375/200, 375/311, 375/316
• US Class Current: 702/94
• CPC Class Codes: G01C 21/20 Instruments for performing navigational calculations G01C21/24, G01C21/26 take precedence
• CPC Class Codes: G01S 19/14 specially adapted for specific applications
• CPC Class Codes: G01S 19/34 Power consumption

Abstract

There is described a method for controlling a navigation device, such as a satellite navigation device like a GPS, GLONASS, GALILEO or other receiver, and a navigation device allowing this control method to be implemented. According to the invention, the operation of the navigation device is adjusted as a function of a measurement of the velocity (v) of the navigation device for the purpose of saving energy. In particular, the operating frequency (f_ck) of the processing unit (18) with which the navigation device is fitted is adjusted to a plurality of so-called reduced operating frequencies (f_ck2, f_ck3, f_ck4, f_ck5) lower than the normal operating frequency (f_ck1) as a function of the value of the velocity measurement (v). The invention is intended in particular to allow a navigation device to be integrated in a portable object of small volume powered by a battery or a rechargeable accumulator, such as a timepiece.

Claims

1. A method for controlling a navigation device, powered by a battery or a rechargeable accumulator, the navigational device including:

receiving means for receiving navigation signals;

processing means for processing said navigation signals and for generating a position, velocity and time measurement based on said navigation signals, said processing means including a processing unit arranged to operate at a first normal operating frequency; and

clock means for generating said normal operating frequency, wherein the control method includes the following steps;

determining the velocity measurement of said navigation device from said navigation signals; and

adjusting the operating frequency of said processing unit to a plurality of reduced operating frequencies lower than said normal operating frequency as a function of the value of said velocity measurement.

2. The control method according to claim 1, wherein the step of adjustment of the operating frequency of said processing unit is achieved by adjusting a division factor of said clock means.

3. The control method according to claim 1, wherein the operating frequency of said processing unit is adjusted to said normal operating frequency when the value of said velocity measurement is higher than a determined limit value.

4. The control method according to claim 1, wherein each operating frequency is associated with a determined range of velocity values.

5. The control method according to claim 4, wherein the operating frequency of said processing unit is adjusted directly or gradually and sequentially to one of said operating frequencies according to whether the value of said velocity measurement is situated in one or the other of said determined ranges of velocity values.

6. A navigation device, powered by a battery or a rechargeable accumulator, comprising:

receiving means for receiving navigation signals;

processing means for processing said navigation signals and for generating a position, velocity and time measurement based on said navigation signals, said processing means including a processing unit arranged to operate at a first normal operating frequency; and

clock means for generating said normal operating frequency,

wherein said navigation device further comprises means for adjusting the operating frequency of said processing unit generated by said clock means to a plurality of reduced operating frequencies lower than said normal operating frequency as a function of the value of said velocity measurement.

7. The navigation device according to claim 6, further comprising means for adjusting a division factor of said clock means as a function of the value of said velocity measurement.

8. The navigation device according to claim 6, further comprising attitude detecting means for automatically re-adjusting the operating frequency of said processing unit to said normal operating frequency.

9. The navigation device according to claim 8, wherein said attitude detecting means for automatically re-adjusting the operating frequency of said processing unit includes a movement or acceleration sensor.

10. The navigation device according to claim 6, being included in a time piece.

11. A method for controlling a navigation device powered by a battery or a rechargeable accumulator, the navigational device comprising:

receiving means for receiving navigation signals;

processing means for processing said navigation signals and for generating a position, velocity and time measurements said processing means including a processing unit arranged to operate at a first normal operating frequency; and

clock means for generating said normal operating frequency, wherein this control method includes the following steps;

measuring the velocity of said navigation device; and

adjusting the operating frequency of said processing unit to a plurality of reduced operating frequencies lower than said normal operating frequency as a function of the value of said velocity measurement

the operating frequency of said processing unit being adjusted to said normal operating frequency while the value of said velocity measurement is higher than a determined limit value.

12. The control method according to claim 11, wherein each operating frequency is associated with a determined range of velocity values.

13. The control method according to claim 12, wherein the operating frequency of said processing unit is adjusted directly or gradually and sequentially to one of said operating frequencies according to whether the value of said velocity measurement is situated in one or the other of said determined ranges of velocity values.

14. A navigation device powered by a battery or a rechargeable accumulator, comprising:

receiving means for receiving navigation signals;

processing means for processing said navigation signals and for generating a position, velocity and time measurement based on said navigation signals, said processing means including a processing unit arranged to operate at a first normal operating frequency; and

clock means for generating said normal operating frequency,

wherein said navigation device further comprises means for adjusting the operating frequency of said processing unit generated by said clock means to a plurality of reduced operating frequencies lower than said normal operating frequency as a function of the value of said velocity measurement,

and wherein said adjusting means adjust the operating frequency of said processing unit to said normal operating frequency while the value of said velocity measurement is higher than a determined limit value.