Machine safety system with mutual exclusion zone

• US 7,768,549 B2
• Filed: 06/08/2001
• Issued: 08/03/2010
• Est. Priority Date: 06/08/2001
• Status: Active Grant

• Current Assignee: Honeywell Incorporated (Honeywell International Inc.)
• Original Assignee: Honeywell International Inc.
• Inventors: Cofer, Darren Duane
• Primary Examiner(s): Czekaj; David
• Application Number:
  US09/877,362
• Publication Number:
  US 20020186299A1
• Time in Patent Office: 3,343 Days
• Field of Search: 348/82, 348/135, 348/143, 348152-156, 348/159, 348/169, 348 86- 93, 382/141, 382/145, 382/152, 382/154
• US Class Current: 348/152
• CPC Class Codes: F16P 3/142 using image capturing devices

Abstract

A safety system receives access monitoring information from sensors to detect intrusion into a mutual exclusion zone by either an operator or mechanical equipment. The border of the mutual exclusion zone is segmented into portals that allow both the operator and equipment to access a common work area such as for loading material. When intrusion into one of the portals is detected, intrusion into any other selected portals triggers a safety violation. Access to the mutual exclusion zone via the other portals is prohibited until the interior of the zone is determined to be empty again.

Claims

1. A mutual exclusion mechanism for a hazardous machine, wherein at least a portion of the machine and at least a portion of an operator can move into and out of a mutual exclusion zone during operation of the machine, but not at the same time, the mechanism comprising:

a sensor that detects a first entrance of one of the portion of the operator or the portion of the machine into the mutual exclusion zone via any of a plurality of border segments bordering the mutual exclusion zone, wherein the sensor and the mutual exclusion zone do not move with the moving portion of the machine; and

a controller that receives information from the sensor regarding the first entrance into the mutual exclusion zone, and controls the machine based on a second entrance of the portion of the operator or the portion of the machine into the mutual exclusion zone via a second segment bordering the mutual exclusion zone, wherein when a portion of the operator enters the mutual exclusion zone the controller prevents a portion of the machine from entering the mutual exclusion zone until the portion of the operator exits the mutual exclusion zone, at which time the controller allows the portion of the machine to enter the mutual exclusion zone.

2. The mutual exclusion mechanism of claim 1 wherein the sensor comprises multiple sensors.

3. The mutual exclusion mechanism of claim 1 wherein the sensor comprises a safety camera.

4. The mutual exclusion mechanism of claim 1 wherein the sensor also detects the presence of one of the portion of the operator or the portion of the machine within the mutual exclusion zone.

5. The mutual exclusion mechanism of claim 1 wherein the controller tracks multiple states of the mutual exclusion zone selected from the group consisting of safe, empty and unsafe.

6. A mutual exclusion mechanism for a hazardous machine, wherein at least a portion of the machine and at least a portion of an operator can move into and out of a mutual exclusion zone during operation of the machine, the mechanism comprising:

a sensor that detects a first entrance of one of the portion of the operator or the portion of the machine into the mutual exclusion zone via any of a plurality of border segments bordering the mutual exclusion zone, wherein the sensor and the mutual exclusion zone do not move with the moving portion of the machine;

a controller that receives information from the sensor regarding the first entrance into the mutual exclusion zone, and controls the machine based on a second entrance of the portion of the operator or the portion of the machine into the mutual exclusion zone via a second segment bordering the mutual exclusion zone; and

wherein the controller generates a trigger list of further segments bordering the mutual exclusion zone when one of the portion of the operator or the portion of the machine have entered the mutual exclusion zone via one segment.

7. The mutual exclusion mechanism of claim 6 wherein entrance by a second of the portion of the operator or the portion of the machine into a segment on the trigger list results in generation of a safety violation.

8. The mutual exclusion mechanism of claim 6 wherein some segments are on the trigger list prior to any segment being entered.

9. A mutual exclusion mechanism for a hazardous machine, wherein at least a portion of the machine and at least a portion of an operator can move into and out of a mutual exclusion zone during operation of the machine, the mechanism comprising:

a sensor that detects a first entrance of one of the portion of the operator or the portion of the machine into the mutual exclusion zone via any of a plurality of border segments bordering the mutual exclusion zone, wherein the sensor and the mutual exclusion zone do not move with the moving portion of the machine;

a controller that receives information from the sensor regarding the first entrance into the mutual exclusion zone, and controls the machine based on a second entrance of the portion of the operator or the portion of the machine into the mutual exclusion zone via a second segment bordering the mutual exclusion zone; and

wherein the sensor also detects the presence of one of the portion of the operator or the portion of the machine within the mutual exclusion zone, the controller generates a trigger list of further segments bordering the mutual exclusion zone when one of the portion of the operator and the portion of the machine have entered the mutual exclusion zone via one segment, and wherein entrance by a second of the portion of the operator or the portion of the machine into a segment on the trigger list results in generation of a safety violation.

10. A method for detecting an object entering a region of interest and controlling entry of objects into the region of interest, the method comprising:

providing a controller and a sensor;

the controller defining a border of the region of interest;

the controller defining two or more border segments of the border;

the controller identifying a set of permissible border segments through which access to the region is permissible;

the sensor sensing when a permissible segment of the border has been crossed; and

the controller determining the set of permissible border segments through which further access to the region is permissible based on which segment of the border has already been crossed.

11. The method of claim 10 wherein after the region of interest has been accessed via a border segment, the set of border segments through which further access to the region is permissible only includes the border segment through which the region of interest has already been accessed.

12. The method of claim 10 further comprising:

the controller restoring the set of permissible border segments through which access to the region of interest is permissible to its initial state when the sensor senses that the interior of the region of interest is no longer occupied.

13. The method of claim 12 wherein the sensor includes a camera and the border crossing and occupancy determinations are made using the camera.

14. A method of controlling a machine, wherein at least a portion of the machine and at least a portion of an operator can move into and out of a predefined mutual exclusion zone during operation of the machine, but not at the same time, the method comprising:

providing a controller and a sensor;

detecting with the sensor whether the portion of the operator or the portion of the machine have entered the predefined mutual exclusion zone;

if the sensor has detected that the portion of the operator or the portion of the machine has entered the mutual exclusion zone, monitoring with the sensor whether one of the portion of the operator or the portion of the machine are still in the predefined mutual exclusion zone; and

if one of the portion of the operator or the portion of the machine are still in the predefined mutual exclusion zone, controlling the machine with the controller based on the entrance of the other of the portion of the operator or the portion of the machine into the predefined mutual exclusion zone such that only one of either the portion of the operator or the portion of the machine are positioned within the predefined mutual exclusion zone at any given time, such that if a portion of the operator is in the mutual exclusion zone, the controller prevents the machine from entering the mutual exclusion zone until the portion of the operator leaves the mutual exclusion zone, at which time the controller allows the machine to enter the mutual exclusion zone.

15. A method of detecting a hazardous condition for an operator of a machine, wherein at least a portion of the machine and at least a portion of the operator can move into and out of a fixed mutual exclusion zone during operation of the machine, but not at the same time, the method comprising:

monitoring the fixed mutual exclusion zone with a sensor;

detecting with the sensor whether the portion of the operator or the portion of the machine have entered the fixed mutual exclusion zone;

if the sensor has detected that the portion of the operator or the portion of the machine has entered the fixed mutual exclusion zone, monitoring whether one of the portion of the operator or the portion of the machine are still in the fixed mutual exclusion zone; and

if one of the portion of the operator or the portion of the machine are still in the fixed mutual exclusion zone, a controller generating a signal based on the entrance of the other of the portion of the operator or the portion of the machine into the fixed mutual exclusion zone;

wherein once the portion of the operator or the portion of the machine leaves the fixed mutual exclusion zone, the other of the portion of the operator or the portion of the machine are allowed to enter the fixed mutual exclusion zone.

16. The method of claim 15 wherein the signal comprises a stop machine signal or a safety warning signal.

17. An apparatus for controlling the operation of a machine, wherein at least a portion of the machine and at least a portion of an operator can move into and out of a defined mutual exclusion zone during operation of the machine, but not at the same time, comprising:

a detector for detecting whether the portion of the operator or the portion of the machine have entered the defined mutual exclusion zone;

a controller coupled to the detector for monitoring whether one of the portion of the operator or the portion of the machine are still in the defined mutual exclusion zone, and if one of the portion of the operator or the portion of the machine are still in the mutual exclusion zone, deactivating the machine if the other of the portion of the operator or the portion of the machine enter into the defined mutual exclusion zone, wherein if the portion of the operator enters the mutual exclusion zone and then exits, the controller allows the portion of the machine to enter the mutual exclusion zone.

18. A mutual exclusion mechanism for a hazardous machine, wherein at least a portion of the machine and at least a portion of an operator can move into and out of a predefined mutual exclusion zone during operation of the machine, but not at the same time, the mechanism comprising:

a sensor that detects a first entrance of one of the portion of the operator or the portion of the machine into the predefined mutual exclusion zone; and

a controller that receives information from the sensor regarding the first entrance into the mutual exclusion zone, and deactivates the machine based on a second entrance of the portion of the operator or the portion of the machine into the mutual exclusion zone such that the machine is activated when only one of either the portion of the machine or the portion of the operator are within the predefined mutual exclusion zone.