Data recording method and device

• US 5,305,214 A
• Filed: 05/21/1993
• Issued: 04/19/1994
• Est. Priority Date: 02/08/1990
• Status: Expired due to Fees

• Current Assignee: Yazaki Corporation
• Original Assignee: Yazaki Corporation
• Inventors: Komatsu, Toshio
• Primary Examiner(s): Chin, Gary
• Application Number:
  US08/064,649
• Time in Patent Office: 333 Days
• Field of Search: 364/424.01, 364/424.03, 364/424.04, 364/565, 340/438, 340/439, 360/5, 360/6, 377/20, 377/24
• US Class Current: 701/35
• CPC Class Codes: G01P 1/122 Speed recorders
• CPC Class Codes: G07C 5/085 using electronic data carriers

Abstract

A recording device records the speed data as a binary number by using a first byte and a part of a second byte, and records the sampling number as a binary number by using the remaining part of the second byte when the number of digits of the sampling number is not greater than the number of bits of the remaining part of the second byte, while recording low-order digits of the sampling number as a binary number by using all the remaining part of the second byte and recording high-order digits of the sampling number and information for indicating record of the high-order digits of the sampling number by using a third byte when the number of digits of the sampling number becomes greater than the number of bits of the remaining part of the second byte.

Claims

1. In a speed data recording method including the steps of sampling speed data to be recorded at a predetermined period, calculating a permissible error range with respect to the speed data at each sampling timing, deciding a longest straight line intersecting said permissible error range calculated, and recording a length of said straight line represented by a sampling number and the speed data at an end point of said straight line, whereby compression processing of the speed data sampled is carried out, and the speed data compressed is recorded into a recording medium;

the improvement wherein said recording step comprises the steps of;

recording said speed data as a binary number by using a first byte and a part of a second byte; and

recording said sampling number as a binary number by using the remaining part of said second byte when the number of digits of said sampling number is not greater than the number of bits of the remaining part of said second byte, while recording low-order digits of said sampling number as a binary number by using all the remaining part of said second byte and recording high-order digits of said sampling number and information for indicating record of said high-order digits of said sampling number by using a third byte when the number of digits of said sampling number becomes greater than the number of bits of the remaining part of said second byte.

2. In a speed data recording device including sampling means for sampling speed data to be recorded at a predetermined period, permissible error range calculating means for calculating a permissible error range with respect to the speed data sampled by said sampling means at each sampling timing, and recording means for deciding a longest straight line intersecting said permissible error range calculated by said permissible error range calculating means and recording a length of said straight line represented by a sampling number obtained by said sampling means and the speed data at an end point of said straight line, whereby compression processing of the speed data sampled is carried out, and the speed data compressed is recorded into a recording medium;

the improvement wherein;

said recording means records said speed data as a binary number by using a first byte and a part of a second byte, and records said sampling number as a binary number by using the remaining part of said second byte when the number of digits of said sampling number is not greater than the number of bits of the remaining part of said second byte, while recording low-order digits of said sampling number as a binary number by using all the remaining part of said second byte and recording high-order digits of said sampling number and information for indicating record of said high-order digits of said sampling number by using a third byte when the number of digits of said sampling number becomes greater than the number of bits of the remaining part of said second byte.