1. A hydraulic flow control valve, comprising:
a spool, and
a flow rate setting adjustment device comprising a rotary control, a spool stop, and a flow rate setting indicator, the flow rate setting adjustment device configured to adjust a flow rate setting of the hydraulic flow control valve by adjusting the amount of travel allowed for the spool in response to axial position adjustment of the spool stop caused by screw-type movement of the rotary control, the flow rate setting adjustment device comprising a flow rate setting indicator arranged for screw-type movement with the rotary control to indicate the flow rate setting upon axial position adjustment of the spool stop caused by screw-type movement of the rotary control.
2. The hydraulic flow control valve of claim 1, wherein the flow rate setting indicator comprises a yieldable detent and screw-type movement stops formed on the rotary control and spaced helically apart from one another for contact with the yieldable detent to stop screw-type movement of the rotary control, each screw-type movement stop corresponding to a predetermined flow rate setting for the hydraulic flow control valve.
3. The hydraulic flow control valve of claim 2, wherein each screw-type movement stop is located in a helical groove of a generally cylindrical side wall of the rotary control, the helical groove receiving the yieldable detent.
4. The hydraulic flow control valve of claim 3, wherein each screw-type movement stop is a recess configured to receive the yieldable detent and formed in the helical groove.
5. The hydraulic flow control valve of claim 3, wherein the helical groove comprises a first closed end and a second closed end spaced helically from the first closed end, and each of the first and second closed ends is arranged to contact the yieldable detent to prevent screw-type movement of the rotary control beyond that closed end.
6. The hydraulic flow control valve of claim 2, comprising a valve housing in which the spool is positioned for movement, wherein the flow rate setting adjustment device comprises a body appended to the valve housing, the spool stop extends through the body into the valve housing, the rotary control is fixed to the spool stop and threaded to the body for screw-type movement of the rotary control relative to the body to move the spool stop axially relative to the body, and the detent is appended to the valve housing and comprises a spring-biased pin extending radially toward a generally cylindrical side wall of the rotary control on which the screw-type movement stops are formed.
7. The hydraulic flow control valve of claim 6, wherein the rotary control comprises an end wall from which the side wall extends axially, the end wall is threaded to the spool stop, the side wall is threaded to the body, and the flow rate setting adjustment device comprises a lock attached to the spool stop and in contact with the end wall to prevent movement of the spool stop relative to the control.
8. The hydraulic flow control valve of claim 1, wherein the flow rate setting indicator comprises visual indicia on the rotary control.
9. The hydraulic flow control valve of claim 1, wherein the flow rate setting indicator is configured to provide tactile feedback upon a flow rate setting adjustment.
10. The hydraulic flow control valve of claim 1, wherein the flow rate setting adjustment device comprises a rotation limiter for limiting screw-type movement of the rotary control.
11. The hydraulic flow control valve of claim 10, wherein the rotation limiter limits screw-type movement of the rotary control to no more than one revolution.
12. The hydraulic flow control valve of claim 1, wherein the spool stop is attached to the rotary control in a manner that will allow movement of the spool stop relative to the rotary control for calibration of the hydraulic flow control valve.
13. The hydraulic flow control valve of claim 12, wherein the flow rate setting adjustment device comprises a lock, the rotary control and the spool stop are threaded to one another, and the lock is arranged to prevent relative rotation between the rotary control and the spool stop.
14. A hydraulic flow control valve, comprising:
a spool, and
a flow rate setting adjustment device comprising a spool stop and a rotary control, the flow rate setting adjustment device configured to adjust a flow rate setting of the hydraulic flow control valve by adjusting the amount of travel allowed for the spool in response to axial position adjustment of the spool stop caused by screw-type movement of the rotary control, the rotary control comprising a multi-start thread.
15. The hydraulic flow control valve of claim 14, wherein the flow rate setting adjustment device comprises a body comprising a multi-start thread cooperating with the multi-start thread of the rotary control.
16. The hydraulic flow control valve of claim 15, wherein each multi-start thread comprises four helical thread elements.
17. The hydraulic flow control valve of claim 15, wherein the spool stop extends through the body, and a generally cylindrical side wall of the rotary control comprises the multi-start thread of the rotary control and surrounds the body for engagement between the multi-start thread of the rotary control and the multi-start thread of the body.
18. A hydraulic flow control valve, comprising:
a spool, and
a flow rate setting adjustment device comprising a rotary control and a stop arrangement, the flow rate setting adjustment device configured to adjust a flow rate setting of the hydraulic flow control valve by adjusting the amount of travel allowed for the spool in response to screw-type movement of the rotary control between predetermined helically-spaced stop points established by the stop arrangement.
19. The hydraulic flow control valve of claim 18, wherein the stop arrangement comprises a yieldable detent and helically-spaced rotation stops formed on the rotary control to receive the yieldable detent, each rotation stop corresponding to a predetermined flow rate setting.
20. The hydraulic flow control valve of claim 18, wherein the rotary control comprises a multi-start thread.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method of controlling the operation of elevator doors for an elevator cab, the method comprising:
acquiring video data comprised of individual frames;
detecting a position of the elevator doors based on the acquired video data;
determining a distance between the elevator doors based on the detected position of the elevator doors; and
controlling the operation of the elevator doors based, at least in part, on the determined distance between the elevator doors.
2. The method of claim 1, wherein detecting the position of the elevator doors based on the acquired video data includes:
applying a line-based method, a mark-based method, or a combination thereof to detect the position of the elevator doors.
3. The method of claim 2, wherein detecting the position of the elevator doors based on the line-based method further includes:
detecting edges within each frame of acquired video data; and
detecting straight lines based on the detected edges.
4. The method of claim 3, wherein detecting the position of the elevator doors based on the line-based method further includes:
omitting detected straight lines occurring at angles outside an expected range of angles; and
merging the remaining straight lines occurring within The expected range of angles into merged lines.
5. The method of claim 4, wherein detecting the position of the elevator doors based on the line-based method further includes:
determining, based on the location of the merged lines, a left-most and right-most edge of the elevator doors that define the position of the elevator doors.
6. The method of claim 2, wherein detecting the position of the elevator doors based on the mark-based method further includes:
detecting a mark positioned on each of the elevator doors; and
determining based on the detected mark the position of the elevator doors.
7. The method of claim I, further comprising:
determining a current state associated with the elevator doors based on the determined distance between the elevator doors in successive frames of the video data; and
controlling the operation of the elevator doors based, in addition, on the determined state of the elevator doors.
8. The method of claim 1, further comprising:
detecting the presence of a person approaching or exiting the elevator cab based on detected locations of the person in successive frames of the video data.
9. The method of claim 8, wherein detecting the presence of a person approaching or exiting the elevator cab based on detected locations of the person in successive frames of the video data includes:
assigning a first timestamp to each pixel within a first frame of video data;
detecting differences in pixels in a second or subsequent frame of video data;
assigning a second timestamp to pixels indicating differences between the first frame of video data and the second or subsequent frame of video data; and
assigning a direction of travel based on a gradient between the timestamps in which the assigned direction points from the earlier-in-time timestamp to the later-in-time timestamp.
10. The method of claim 9, further comprising:
detecting a person approaching or exiting the elevator car,
wherein controlling the state of the elevator doors includes changing the state of the elevator doors from a door closing state to a door opening state based, at least in part, on the detection of the person approaching or exiting the elevator cab.
11. The method of claim 1, wherein controlling the elevator door operation includes controlling a state of the elevator doors and a speed associated with the elevator doors during opening andor closing of the elevator doors, and wherein the speed of the elevator doors is controlled based, at least in part, on the determined distance between the elevator doors.
12. A system for controlling elevator door operation based on video data, the system comprising:
at least one video detector configured to acquire and transmit video data in the form of a plurality of images;
a video recognition system operably connected to receive the video data from the at least one video detector, wherein the video recognition system is operable to:
detect a position of the elevator doors based on the acquired video data; and
determine a distance between the doors based on the detected position of the elevator doors for each of the plurality of frames; and
an elevator controller operably connected to receive the distance data determined by the video recognition system, wherein the elevator controller is configured to control the operation of the elevator doors based, at least in part, on the determined distance between the elevator doors.
13. The system of claim 12, wherein the video recognition system is configured to detect the position of the elevator doors by employing a line-based method, a mark-based method, or a combination thereof.
14. The system of claim 12, wherein the elevator controller is configured to control a speed associated with an opening andor closing of the elevator doors based, at least in part, on the distance determined by the video recognition system.
15. The system of claim 12, wherein the elevator controller is configured to determine a current state associated with the elevator doors based on the distance determined in successive frames of the video data.
16. The system of claim 15, wherein the elevator controller is configured to control a length of time the elevator doors are maintained in an opened or closed state based on the determined state of the elevator doors.
17. The system of claim 12, wherein the video recognition system is operable to detect the presence of a person approaching or exiting an elevator cab.
18. The system of claim 17, wherein the video recognition system is further operable to detect a direction associated with the detected person based on successive frames of video data.
19. The system of claim 18, wherein the elevator controller is configured to control the operation of the elevator doors based, at least in part, on the detected presence of a person approaching or exiting the elevator cab.
20. A video recognition system comprising:
means for receiving video data captured by a video detector;
means for detecting doorframe edges of elevator doors within a field of view of the video detector based on the video data;
means for determining a distance between the elevator doors based on the detected doorframe edges; and
means for generating an output based on the determined distance between the elevator doors.
21. The video recognition system of claim 20, wherein the means for detecting the position of the elevator doors includes:
an edge detector that is configured to detect edges within the received video data;
a line detector that is configured to detect straight lines within the detected edges;
a line selector that is configured to select one or more of the detected straight lines occurring within a range of allowable angles;
a line merger that is configured to merge discontinuous portions of the selected straight lines; and
a door edge detector that is configured to select from the merged, straight lines one or more lines representing the doorframe edges of the elevator doors.
22. The video recognition system of claim 20, wherein the means for determining a distance between the elevator doors based on the detected doorframe edges includes:
a distance determining device that is configured to determine the distance between the detected doorframe edges based on a number of pixels located between the detected doorframe edges.