Portable GPS type distance/speed meter capable of selectively using doppler speed measuring method

• US 6,388,613 B1
• Filed: 03/29/2000
• Issued: 05/14/2002
• Est. Priority Date: 03/30/1999
• Status: Expired due to Fees

• Current Assignee: Morita Digital LLC (Intellectual Ventures LLC)
• Original Assignee: Seiko Instruments Incorporated (Seiko Group)
• Inventors: Sakumoto, Kazumi, Odagiri, Hiroshi, Nagatsuma, Hideaki
• Primary Examiner(s): Blum, Theodore M.
• Application Number:
  US09/537,941
• Time in Patent Office: 776 Days
• Field of Search: 342/357.08, 701/213, 482/8
• US Class Current: 342/357.42
• CPC Class Codes: G01C 21/20 Instruments for performing navigational calculations G01C21/24, G01C21/26 take precedence
• CPC Class Codes: G01P 3/50 for measuring linear speed G01P3/56 takes precedence
• CPC Class Codes: G01S 19/39 the satellite radio beacon positioning system transmitting time-stamped messages, e.g. GPS [Global Positioning System], GLONASS [Global Orbiting Navigation Satellite System] or GALILEO
• CPC Class Codes: G01S 19/52 Determining velocity

Abstract

A portable type distance/speed meter is designed for measuring a travel distance and a travel speed when a user walks, or runs, while realizing a correct average speed calculation in response to GPS electromagnetic waves receiving conditions. The portable type distance/speed meter is arranged by: a GPS (Global Positioning System) receiver for receiving GPS electromagnetic waves transmitted from GPS satellites to acquire positioning data from the received GPS electromagnetic waves; first distance calculating means for calculating a travel distance of a user as a first distance based upon a difference between positional information contained in the positioning data which are acquired at two positions; timer means for measuring travel time of the user over the first distance; first speed calculating means for calculating a travel speed of the user as a first speed based upon both the first distance calculated by the first distance calculating means and the travel time measured by the timer means; abnormal value detecting means for detecting an abnormal value of the first speed calculated by the first speed calculating means; average speed calculating means for calculating an average travel speed of, the user based upon the first speed calculated by the first speed calculating means in the case that the abnormal value of the first speed is not detected by the abnormal value detecting means; and distance accumulating means for accumulating the first distance calculated by the first distance calculating means so as to calculate an accumulated distance in the case that the abnormal value of the first speed is not detected by the abnormal value detecting means.

Claims

1. A portable distance/speed meter that may be carried by a user, comprising:

a GPS (Global Positioning System) receiver for receiving GPS electromagnetic waves transmitted from GPS satellites and acquiring positioning data from the received GPS electromagnetic waves;

first distance calculating means for calculating a travel distance of the user between two different positions as a first distance based upon a difference between positional information contained in the positioning data acquired at the two positions;

timer means for measuring travel time of the user over the first distance;

first speed calculating means for calculating a travel speed of the user as a first speed based upon both the first distance calculated by the first distance calculating means and the travel time measured by the timer means;

abnormal value detecting means for detecting an abnormal value of the first speed calculated by the first speed calculating means, the abnormal value being a calculated speed value larger than that which the user can travel;

average speed calculating means for calculating an average travel speed of the user based upon first speed values calculated by the first speed calculating means excluding abnormal values of the first speed detected by the abnormal value detecting means; and

distance accumulating means for accumulating the first distance calculated by the first distance calculating means so as to calculate an accumulated distance excluding first distance values corresponding to abnormal values of the first speed detected by the abnormal value detecting means.

3. A portable distance/speed meter as claimed in claim 1 or claim 2;

wherein the abnormal value detecting means compares a present speed value of the first speed with a preceding speed value thereof, which are calculated by the first speed calculating means, and detects the first speed as being an abnormal value when the first speed corresponding to the present speed value varies by more than a predetermined amount from the first speed corresponding to the preceding speed value.

2. A portable distance/speed meter that may be carried by a user, comprising:

a GPS (Global Positioning System) receiver for receiving GPS electromagnetic waves transmitted from GPS satellites and acquiring positioning data from the received GPS electromagnetic waves;

first distance calculating means for calculating a travel distance of the user between two different positions as a first distance based upon a difference between positional information contained in the positioning data acquired at the two positions;

second speed calculating means for calculating a travel speed of the user as a second speed based upon Doppler shift frequency information contained in the positioning data;

timer means for measuring a first travel time of the user over the first distance and a second travel time of the user at the second speed;

first speed calculating means for calculating a travel speed of the user as a first speed based upon both the first distance calculated by the first distance calculating means and the first travel time measured by the timer means;

second distance calculating means for calculating a travel distance of the user as a second distance based upon both the second speed calculated by the second speed calculating means and the second travel time measured by the timer means;

abnormal value detecting means for detecting an abnormal value of the first speed calculated by the first speed calculating means, the abnormal value being a calculated speed value larger than that which the user can travel;

speed selecting means for selecting the first speed when the abnormal value of the first speed is not detected by the abnormal value detecting means, and for selecting the second speed when the abnormal value of the first speed is detected by the abnormal value detecting means;

distance selecting means for selecting the first distance when the abnormal value of the first speed is not detected by the abnormal value detecting means, and for selecting the second distance when the abnormal value of said first speed is detected by the abnormal value detecting means;

average speed calculating means for calculating an average travel speed of the user by employing the selected one of the first speed and the second speed selected by the speed selecting means; and

distance accumulating means for calculating an accumulated distance by employing the selected one of the first distance and the second distance selected by the distance selecting means.

4. A portable distance/speed meter that may be carried by a user, comprising:

a GPS (Global Positioning System) receiver for receiving GPS electromagnetic waves transmitted from GPS satellites and acquiring positioning data from the received GPS electromagnetic waves;

a first distance calculating circuit for calculating a travel distance of the user between two different positions as a first distance based upon a difference between positional information contained in the positioning data acquired at the two positions;

a timer for measuring travel time of the user over the first distance;

a first speed calculating circuit for calculating a travel speed of the user as a first speed based upon both the first distance calculated by the first distance calculating circuit and the travel time measured by the timer;

an abnormal value detecting circuit for detecting an abnormal value of the first speed calculated by the first speed calculating circuit, the abnormal value being a calculated speed value larger than that which the user can travel;

an average speed calculating circuit for calculating an average travel speed of the user based upon first speed values calculated by the first speed calculating circuit excluding abnormal value of the first speed detected by the abnormal value detecting circuit; and

a distance accumulating circuit for accumulating the first distance calculated by the first distance calculating circuit so as to calculate an accumulated distance excluding first distance values corresponding to abnormal values of the first speed detected by the abnormal value detecting circuit.

5. A portable distance/speed meter according to claim 4;

wherein the abnormal value detecting circuit compares a present first speed value with a preceding calculated first speed value and determines that the present first speed value is an abnormal value when it varies from the preceding first speed value by more than a predetermined amount.

6. A portable distance/speed meter that may be carried by a user, comprising:

a GPS (Global Positioning System) receiver for receiving GPS electromagnetic waves transmitted from GPS satellites and acquiring positioning data from the received GPS electromagnetic waves;

a first distance calculating circuit for calculating a travel distance of the user between two different positions as a first distance based upon a difference between positional information contained in the positioning data acquired at the two positions;

a second speed calculating circuit for calculating a travel speed of the user as a second speed based upon Doppler shift frequency information contained in the positioning data;

a timer for measuring a first travel time of the user over the first distance and a second travel time of the user at the second speed;

a first speed calculating circuit for calculating a travel speed of the user as a first speed based upon both the first distance calculated by the first distance calculating circuit and the first travel time measured by the timer;

a second distance calculating circuit for calculating a travel distance of the user as a second distance based upon both the second speed calculated by the second speed calculating circuit and the second travel time measured, by the timer;

an abnormal value detecting circuit for detecting an abnormal value of the first speed calculated by the first speed calculating circuit, the abnormal value being a calculated speed value larger than that which the user can travel;

a speed selecting circuit for selecting the first speed when the abnormal value of the first speed is not detected by the abnormal value detecting circuit, and for selecting the second speed when the abnormal value of the first speed is detected by the abnormal value detecting circuit;

a distance selecting circuit for selecting the first distance when the abnormal value of the first speed is not detected by the abnormal value detecting circuit, and for selecting the second distance when the abnormal value of the first speed is detected by the abnormal value detecting circuit;

an average speed calculating circuit for calculating an average travel speed of the user by employing the selected one of the first speed and the second speed selected by the speed selecting circuit; and

a distance accumulating circuit for calculating an accumulated distance by employing the selected one of the first distance and the second distance selected by the distance selecting circuit.

7. A portable distance/speed meter according to claim 6;

wherein the abnormal value detecting circuit compares a present first speed value with a preceding calculated first speed value and determines that the present first speed value is an abnormal value when it varies from the preceding first speed value by more than a predetermined amount.

8. A portable distance/speed meter comprising:

a receiver for receiving GPS signals and acquiring positioning data therefrom; and

a processing circuit for processing the positioning data to determine a first distance value traveled by a user between two locations corresponding to sequentially received GPS signals, calculating a speed of the user while traveling between the two locations by a first method comprising an arithmetic method based on the positioning data corresponding to the two locations and a traveling time of the user between the two locations and a second method comprising a Doppler shift frequency method, determining abnormal values comprising speed values calculated by the first method which vary from a preceding calculated speed value by more than a predetermined amount, substituting speed values calculated by the second method for abnormal values, and calculating at least one of an accumulated distance traveled by the user by adding first distance values and an average speed of the user by adding calculated speed values and taking into account substituted speed values in determining the accumulated distance or average speed.

9. A portable distance/speed meter according to claim 8;

wherein the processing circuit calculates an average speed of the user by averaging speed values calculated based on first distance values, and excluding abnormal values of the calculated speed.