Position measuring system, position measuring unit, and position measuring method

• US 6,236,356 B1
• Filed: 03/31/1999
• Issued: 05/22/2001
• Est. Priority Date: 04/03/1998
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Hayashi, Nobuyuki
• Primary Examiner(s): Gregory, Bernarr E.
• Application Number:
  US09/283,085
• Time in Patent Office: 783 Days
• Field of Search: 342/357-1-3, 244/3.14
• US Class Current: 342/357.34
• 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 19/51 Relative positioning
• CPC Class Codes: G01S 5/0072 Transmission between mobile stations, e.g. anti-collision systems

Abstract

In a first position measuring unit, a selecting portion selects radio waves containing available position measured information from a plurality of satellites through an antenna. A communicating portion communicates with a second position measuring unit. The first and second position measuring units select radio waves that can be shared therewith. The first and second position measuring units measure their positions using the same set of the selected radio waves. Measured results of the second position measuring unit are transmitted to the first position measuring unit. A calculating portion of the first position measuring unit calculates a relative distance between the first and second position measuring units corresponding to the difference between the measured results of the first and second position measuring units.

Claims

1. A position measuring system for measuring a relative position between first and second receiving units using position measured information received from a plurality of satellites, comprising:

first and second position measuring means included in said first and second receiving units, respectively, for measuring respective first and second current positions of said first and second position measuring means using said position measured information received from a same set of satellites selected from said plurality of satellites, wherein

said first and second receiving units search for available satellites and communicate with each other a result of this search, based on said result said same set of satellites is selected and an error message is output when said same set of satellites cannot be selected, and

wherein said relative position between said first and second receiving units is obtained by calculating differences between said results measured by said first and second position measuring means.

2. A position measuring unit for measuring a distance from a remote position measuring unit using position measured information received from a plurality of satellites, comprising:

communicating means for enabling communication with said remote position measuring unit, wherein said remote position measuring unit includes first position measuring means,

second position measuring means for measuring said distance from said remote position measuring unit using said positioned measured information received from a same set of satellites selected from said plurality of satellites, wherein

said first position measuring means of said remote position measuring unit and said second position measuring means of said position measuring unit search for available satellites and communicate with each other using said communicating means a result of this search, based on said result said same set of satellites is selected and an error message is output when said same set of satellites cannot be selected; and

distance calculating means for calculating said distance from said remote position measuring unit by calculating differences between measurements determined by said first and second position measuring means shared by a communication between said position measuring unit and said remote position measuring unit using said communicating means.