Detection of obstruction of doors
First Claim
1. A method of testing the integrity of a sensing element for an obstruction detection system, said sensing element defining an interior space containing a fluid and being adapted to produce a detectable change in pressure in said fluid if an obstruction is encountered, said testing method comprising:
- applying to the interior space of the sensing element a predetermined change in pressure of fluid;
providing for relief of said changed pressure in a predetermined manner;
and assessing a characteristic of the manner in which said change in pressure is actually relieved to provide, in comparison with said predetermined manner, an indication of said integrity.
4 Assignments
0 Petitions
Accused Products
Abstract
Pneumatic sensing elements are provided on the leading edges of power operated vehicle doors. If an obstruction is encountered on closing the doors, the sensing elements are compressed to cause a pressure increase which is sensed and is used to open the doors. Each time the doors are opened, operation of the system is tested by applying a gas pressure pulse to the system. The pressure pulse is gradually vented through a fixed orifice. The pressure in the system produced by the pressure pulse is sensed and is applied to a controller which compares the pressure pulse information with information for known pulses for a normally operating system and for system failures caused, for example, either by a leak or by a blockage in the system.
-
Citations
16 Claims
-
1. A method of testing the integrity of a sensing element for an obstruction detection system, said sensing element defining an interior space containing a fluid and being adapted to produce a detectable change in pressure in said fluid if an obstruction is encountered, said testing method comprising:
-
applying to the interior space of the sensing element a predetermined change in pressure of fluid;
providing for relief of said changed pressure in a predetermined manner;
and assessing a characteristic of the manner in which said change in pressure is actually relieved to provide, in comparison with said predetermined manner, an indication of said integrity. - View Dependent Claims (2, 3)
-
-
4. A method of testing the integrity of a sensing element for an obstruction detection system, said sensing element defining an interior space containing a fluid and being adapted to produce a detectable change in pressure in said fluid if an obstruction is encountered, said testing method comprising:
-
introducing a small quantity of said fluid into the interior of the sensing element, to produce a predetermined pulse of increased pressure in said fluid;
providing for escape of fluid from the interior of said sensing element, to relieve said increased pressure in a predetermined manner;
measuring the rate at which pressure in the sensing element changes in response to said pressure pulse applied thereto; and
comparing said measured rate at which pressure changes with a predetermined rate of pressure change, to provide an indication of said integrity of the sensing element.
-
-
5. An obstruction detection system comprising a sensing element, said sensing element defining an interior space containing a fluid, said sensing element being adapted to cause a detectable pressure change in said fluid therein if an obstruction is encountered, and further comprising apparatus for testing the integrity of at least said sensing element, said testing apparatus comprising:
-
a device for applying a predetermined change in pressure to the interior of the sensing element, said changed pressure being arranged to be relieved in a predetermined manner; and
assessment apparatus for assessing the manner in which the pressure is actually relieved to provide, in comparison with said predetermined manner, an indication of said integrity. - View Dependent Claims (6, 7, 8, 9, 10, 11, 12, 13)
-
- 14. In combination with a pneumatically operated vehicle door system including an obstruction detecting system comprising a flexible sensing element forming a leading edge of a vehicle door and having a gas filled interior space connected through pipes to a gas pressure sensor which generates a signal in response to pressure changes in said interior space caused by said sensing element being compressed by an obstruction when said vehicle door is closing, a testing system for said obstruction detecting system including a manifold chamber connected between said pipes and said pressure sensor, an orifice providing a controlled vent to said manifold chamber, means for applying an increased pressure gas pulse to said manifold chamber when said vehicle door is opened, and means responsive to said pressure sensor when a gas pulse is applied to said manifold chamber for detecting gas leaks and blockages in said obstruction detecting system.
Specification