Speed independent system for obtaining preselected numbers of samples from object moving along fixed path

• US 4,441,196 A
• Filed: 02/28/1980
• Issued: 04/03/1984
• Est. Priority Date: 02/28/1980
• Status: Expired due to Term

• Current Assignee: Servo Corporation of America
• Original Assignee: Servo Corporation of America
• Inventors: Sanville, W. Woodward
• Primary Examiner(s): Thomas, James D.
• Assistant Examiner(s): Williams, Jr., Archie E.
• Application Number:
  US06/125,487
• Time in Patent Office: 1,496 Days
• Field of Search: 235/92 T, 235/92 FQ, 235/92 TC, 235/92 DN, 235/92 DM, 235/92 CP, 235/92 AE, 340/146.3 K, 340/23, 340/47, 340/670, 364/111, 364/561, 364/569, 364/174, 364/178, 364/179, 364/565, 364/438, 364/426, 324/160, 324/161, 324/166, 324/178, 368/6, 368/8, 368/89, 368/2, 368/108, 368/111, 246/169 D, 246/169 R, 246/169 S, 246/169 A, 246/247, 246/255, 246/316, 246/182 A, 246/182 R, 246/182 B, 73/1 D, 73/488, 73/510, 73/518, 250/359.1, 250/221.1, 250/222.1, 250/223, 377/44, 377/9, 377/20, 328/5
• US Class Current: 377/9
• CPC Class Codes: B61K 9/06 by detecting or indicating heat radiation from overheated axles
• CPC Class Codes: G04F 5/00 Apparatus for producing preselected time intervals for use as timing standards generating clock signals for electric digital computers G06F1/04

Abstract

A speed independent system is used for obtaining a preselected number of samples from an object moving along a fixed path, such as a railroad train passing through a sensing zone along the section of track. The sensing zone is defined by a pair of wheel sensors. Upstream of the sensing zone a third sensor is positioned. The distance between the third sensor and the closer of the pair of sensors comprises a reference distance which is the length of the sensing zone multiplied by a known multiple. The time for the train to pass through the reference distance is obtained and then divided by a divisor comprising the product of the known multiple and the desired number of samples to obtain a single interval. During the time the train passes through the sensing zone consecutive intervals are counted off to obtain the desired number of samples.

Claims

1. A method for obtaining a predetermined number of data samples of equal time intervals from an object passing through a sensing zone independent of the speed at which the object passes through the sensing zone by dividing the time in which the object passes through the sensing zone into said predetermined number of equal time intervals regardless of the speed of the object and samping the object during each of the intervals, said method comprising the steps of:

(a) establishing a first reference distance upstream of said sensing zone which is a known multiple of the length of said sensing zone;

(b) measuring the time required for the object to pass through said reference distance;

(c) dividing the aforementioned time by a divisor comprising the product of said known multiple and the predetermined number whereby to obtain a single time interval;

(d) consecutively counting off single time intervals during the time said object passes through the sensing zone; and

,

(e) obtaining a data sample from said object during each of said single intervals whereby to obtain said predetermined number of data samples regardless of the speed of the object.

2. The method in accordance with claim 1 including the further step of establishing another reference distance downstream of said sensing zone.

3. The method in accordance with claim 1 wherein said reference distance is established immediately upstream and adjacent to said sensing zone.

4. The method in accordance with claim 3 including the further steps of establishing another reference distance equal to said first reference distance downstream of said sensing zone.

11. The method in accordance with claim 2 wherein said other reference distance is equal to the first reference distance.

5. A system for obtaining a predetermined number of data samples from an object passing through a sensing zone by dividing the time in which the object passes through the sensing zone into a predetermined number of equi-timed intervals and sampling the object during each of the intervals comprising:

first and second sensors in the path of motion of said object defining the beginning and end of said sensing zone;

data sampling means adapted to obtain data from said object when said object is in said sensing zone;

sensing means positioned upstream of said sensing zone for defining a reference zone distance in the path of motion of said object, the length of said reference zone distance being a known multiple of the length of said sensing zone distance;

first timer means connected to said sensing means to determine the time required for said object to traverse said reference distance and to generate a number value output indicative of said time;

divider means connected to said first timer and adapted to divide said number value by the product of said predetermined number and known multiple to obtain a time interval value; and

,

second timer means connected to said first and second sensors and to the output of said divider to generate a signal to said data sampling means for each elapsed time interval as the object moves through said sensing zone whereby said data sampling means may obtain said predetermined number of data samples from said object as said object moves through said sensing zone.

6. The system in accordance with claim 5 further comprising a third sensor and wherein said sensing means comprises said third sensor and one of said first and second sensors.

7. The system in accordance with claim 5 further comprising a clock pulse generator and said first timer means comprises a counter for counting pulses from said generator.

8. The system in accordance with claim 6 wherein said second timer means comprises a second counter for counting pulses from said generator.

9. The system in accordance with claim 5 further comprising additional sensing means downstream of said sensing zone for defining a second reference zone distance in the path of motion of said object, said second reference being said known multiple of the length of said sensing zone distance.

10. The system in accordance with claim 5 wherein said object comprises a railroad car wheel and said first and second sensors comprise wheel sensors.