Ultrasonic passenger detection

• US 8,791,839 B2
• Filed: 05/13/2009
• Issued: 07/29/2014
• Est. Priority Date: 06/05/2008
• Status: Active Grant

• Current Assignee: Wabtec Holding Corp (Westinghouse Air Brake Technologies Corporation)
• Original Assignee: Wabtec Holding Corp (Westinghouse Air Brake Technologies Corporation)
• Inventors: Citta, James W., Urman, Robert
• Primary Examiner(s): Wu, Daniel
• Assistant Examiner(s): Tang, Son M
• Application Number:
  US12/992,319
• Publication Number:
  US 20110132093A1
• Time in Patent Office: 1,903 Days
• Field of Search: 340/518, 340/528, 340/545.1, 340/552, 340/561, 340/943, 736/32, 367/93, 367/95
• US Class Current: 340/943
• CPC Class Codes: E05F 2015/433 using reflection from the obstruction
• CPC Class Codes: E05Y 2900/506 for buses
• CPC Class Codes: E05Y 2900/51 for railway cars or mass transit vehicles
• CPC Class Codes: G01S 15/04 Systems determining presence of a target
• CPC Class Codes: G01S 7/52006 with provision for compensating the effects of temperature
• CPC Class Codes: G01S 7/527 Extracting wanted echo signals Doppler systems G01S15/50

Abstract

A method and apparatus of recognizing the presence of a passenger in front of a door of a transit vehicle comprises directing an ultrasound transmitter/receiver at a volume of space adjacent the door, emitting an ultrasound pulse into the empty volume, recording and integrating intensity of the echoes and storing the integrated value as a standard value, repeatedly emitting an ultrasound pulse into the volume, and comparing the integrated values to the standard value.

Claims

1. A method of recognizing the presence of a passenger in front of a door of a transit vehicle comprising the steps of:

at preset multiple positions of the door as it is opening or closing directing an ultrasound transmitter/receiver at a volume of space adjacent the door and generally directed at the floor in front of the door;

emitting an ultrasound pulse via the transmitter/receiver into said volume of space while the space is not occupied by a passenger;

recording the ultrasound echoes from objects in the volume of space for at least one response period;

integrating intensity of said echoes during at least a fixed portion of the at least one response period and storing the integrated values as standard values;

repeatedly at preset multiple positions of the door as it is opening or closing emitting an ultrasound pulse via the transmitter/receiver into said volume of space, recording the ultrasound echoes, and integrating the intensity of said echoes during said fixed period; and

repeatedly comparing the integrated values to the stored standard value such that when the integrated value differs from the standard value for each preset position by a given amount, a passenger is deemed to have entered the volume of space adjacent the door.

2. The method according to claim 1, wherein multiple ultrasound transmitter/receivers are directed at the volume of space adjacent the door and generally directed at the floor, and summing the integrated echoes received at each transmitter/receiver.

3. The method according to claim 1, wherein the at least one response period is insufficiently long for an echo to be received from the floor.

4. The method according to claim 1, wherein multiple separate response periods are recorded and integrated to establish standard values for each response period.

5. The method according to claim 1, wherein multiple response periods, at least one sufficiently long enough to receive an echo from the floor and one insufficiently long to receive an echo from the floor are recorded and integrated to establish standard values for each response period.

6. A system for recognizing the presence of a passenger adjacent a door of a transit vehicle comprising:

an ultrasound transmitter/receiver directed at a volume of space adjacent said door and generally directed at the floor near the door;

a controller for triggering an ultrasound pulse via the transmitter/receiver into said volume of space at preset multiple positions of the door as it is opening or closing while the space is not occupied by a passenger and recording the ultrasound echoes from objects in the volume of space for at least one response period and integrating the intensity of the echoes during at least a fixed portion of the at least one response period and storing the integrated values as standard values;

said controller programmed to repeatedly emit an ultrasound pulse via the transmitter/receiver into said volume of space adjacent the door, to record the ultrasound echoes, and to integrate the intensity of said echoes during said fixed period; and

said controller further programmed to repeatedly compare the integrated values to standard values for each preset position.

7. A system according to claim 6 comprising multiple ultrasound transmitter/receivers directed at the volume of space adjacent the door generally directed at the floor and wherein the integrated echoes of all transmitter/receivers are summed.

8. The system according to claim 6, wherein the at least one response period is insufficiently long for an echo to be received from the floor.

9. The system according to claim 6, wherein multiple separate response periods are recorded and integrated to establish standard values for each response period.

10. The system according to claim 6, wherein multiple response periods, at least one sufficiently long enough to receive an echo from the floor and one insufficiently long to receive an echo from the floor, are recorded and integrated to establish standard values for each response period.