Normalization of inductive vehicle detector outputs

• US 6,988,052 B2
• Filed: 04/04/2005
• Issued: 01/17/2006
• Est. Priority Date: 03/08/2002
• Status: Expired due to Fees

• Current Assignee: Inductive Signature Technologies Incorporated
• Original Assignee: Inductive Signature Technologies Incorporated
• Inventors: Hilliard, Steven R., Yerem, Geoffrey C.
• Primary Examiner(s): Raymond, Edward
• Application Number:
  US11/098,744
• Publication Number:
  US 20050182597A1
• Time in Patent Office: 288 Days
• Field of Search: 702/182, 702185-188, 340/933, 340/941, 701/1, 701/23, 701/29, 701/36, 701/121, 324/160, 324/162, 324/163, 324/179
• US Class Current: 702/182
• CPC Class Codes: G08G 1/042 using inductive or magnetic detectors

Abstract

Methods for a determining a normalized lane occupancy and for monitoring signal quality for a vehicle detection system. Such methods include, in one embodiment, measuring a speed of a vehicle with an inductive vehicle detector, measuring an on-time for the vehicle crossing a wire loop sensor of the inductive vehicle detector, determining an inductive length of the vehicle from the measured speed, and computing a normalized on-time by subtracting a longitudinal length of the wire loop sensor from the inductive length and dividing the difference by the measured speed.

Claims

1. A method for normalizing lane occupancy, said method comprising the steps of:

a) measure a speed of a vehicle with an inductive vehicle detector;

b) measure an on-time for said vehicle crossing a wire loop sensor of said inductive vehicle detector

c) determine an inductive length of said vehicle from said measured speed; and

d) compute a normalized on-time by subtracting a longitudinal length of said wire loop sensor from said inductive length and dividing the difference by said measured speed.

2. The method of claim 1 further including a step of applying a correction to said inductive vehicle detector whereby said inductive vehicle detector calculates a normalized lane occupancy.

3. The method of claim 1 further including a step of adjusting a timing and a duration of a plurality of pulses generated by said inductive vehicle detector.

4. A method for determining a normalized lane occupancy for a vehicle detection system, said method comprising the steps of:

a) measuring a speed and an inductive length of a vehicle as a function of vehicle speed, and a loop detector on-time whereby said inductive length equals said speed multiplied by said loop detector on-time;

b) subtracting a longitudinal dimension of a wire loop from said inductive length;

c) computing a normalized on-time wherein said normalized on-time equals said inductive length minus said longitudinal dimension of said inductive loop, all divided by said speed; and

d) measuring a total time corresponding to a measurement period;

whereby said normalized lane occupancy is reported as a percentage of said normalized on-time divided by said total time.