Slide Gate Anti-Slam Project
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Synopsis
The objective of this project is to provide logic and instrumentation that will eliminate the slamming of the gates that occurs during high fish traffic.
Pictures
Pictures
Current Project Status
Troy 08:15, 27 November 2007 (PST) Overall this project has proven to be very successful. The 2007 season ended with zero gate failures. There were a few minor problems that are captured in the following article.
Snake River Slide Gate 2007 Season Summary.pdf
Troy 09:31, 4 January 2007 (PST) The descrete sensor have proven to work well on GOJ's slide gates. Conduit installation is being done by COE employees and sensor and supplies have been ordered for the installation of 3 sensors per gate. The logic is complete for GOJ (PV and PLC) and has been test in the lab and on the gates at the NMFS shop. The analog sensor have been tested and the results are listed in the 'issues' section.
The 3 sensor logic has proven to be a success. The basic concept of the logic is to move a different T/O (Travel Open time) to the T/O timer under specific conditions. The sensors are mounted behind and below the gate and pick up a flag that is attached to the gate. Sensor 1 is the sensor closest to the gate and Sensor 3 is the furthest from the gate. The following are the basic 'rules' for the logic.
3 Sensor Sequence
- If the gate is closing and a second RTO (Request To Open) is received and only Sensor 1 is on the PLC will send a secondary T/O time to the T/O timer.
- If the gate is closing and a second RTO (Request To Open) is received and Sensor 1 and 2 are on the PLC will send a tertiary T/O time to the T/O timer.
- If the gate is closing and a second RTO (Request To Open) is received and all 3 sensors are on the PLC will send a quaternary T/O time to the T/O timer.
The sensors also are used to determine if the gate is stuck open or closed. There is logic in place to alert site personnel that there is a problem with either the gate or the sensors. Gate issues will hopefully be addressed by site personnel and sensor issue will hopefully be passed on to PSMFC and addressed by PSMFC.
With the help of Jim Simmonson (NMFS) the gates have had a flag added, a mounting bracket for the sensor added, a UHMW cover with a pass through for the flag added and a hinged safety cover added. Jeff (NMFS) added a mounting bracket for a field junction box.
Two types of instrumentation are being tested.
Issues
Troy 09:44, 4 January 2007 (PST)The analog sensor was tested yesterday using a cylinder from GRJ. The cylinder has a 24 inch stroke. When the PLC logic is configured such that it uses similar logic to that of the 3 sensor discrete logic it does eliminate a majority of the double slams.
- If the gate is 0 to 6" open and a second RTO (Request To Open) is received send the normal T/O (Travel Open time) to the T/O timer.
- If the gate is 6 to 12" open and a second RTO is received send a secondary T/O to the T/O timer.
- If the gate is 12 to 18" open and a second RTO is received send a tertiary T/O to the T/O timer.
- if the gate is 18 to 24" open and a second RTO is received send a quaternary T/O to the T/O timer.
Testing in the this configuration was promising enough to attempt different logic (it appeared to be slow but still worked).
New logic was tried-
- If the gate is traveling open and the value of the analog sensor was greater than x invoke a 'soft open'.
- if the gate is traveling closed and the value of the analog sensor is less than y invoke a 'soft close'.
Testing revealed that the optimum x was value that represent 10 inches or less and y was a value that represent 19 inches or more.. The problem arose when the previous RTO did not cause that gate to travel past the y value. This resulted in the gate slamming open and then 'soft closing' the entire way.
Conclusion: While a nice instrument it can be replaced by 3 sensors at 1/2 the cost with no moving parts and no changes to the PLC rack configuration.
Recommendations for Future Enhancements
Troy 08:03, 27 November 2007 (PST) Move the sensors for E Gate at GRJ to the other side of the gate. This will place the sensors closer to the flag and hopefully eliminate erroneous 'Gate Trouble' alarms. There are currently plans to coordinate with NFMS to do the change this winter.
Journal
Troy 13:12, 3 October 2007 (PDT)Completed the season at LMJ without a gate failure. The site biologist is extremely please and could not re-call hearing a gate slam all season long.
Installed a 2nd SOL on GRJ's sample gate to eliminate the slamming of that gate. PLC programed to treat the sample gate in the same manner as a slide gate in that it has a soft close and soft open.
Troy 14:31, 8 May 2007 (PDT)Documented over 1900 secondary T/O used on A gate at GRJ out of ~10K diversion during a 3-4 day period in the middle of the peak run. Several Tertiary and Quaternary T/O times used as well. The Secondary could arguably be considered the most valuable as far as saving wear and tear on the gate because the gate is traveling the furthest distance when this condition is true.
Troy 11:12, 15 February 2007 (PST) GOJ's gates installed and tested. GRJ's gates rebuilt by Jim Simonson and tested. These gates are ready to be returned and installed.
Troy 08:17, 10 January 2007 (PST)GOJ gates complete and are being returned to GOJ for install.
Troy 09:56, 7 December 2006 (PST)Three sensor logic proven to be a success on GOJ's B gate at NMFS Pasco shop. SOP started for setting up a gate with 3 sensors. The basic concept of 3 sensors is to get a rough idea of where the gate is while it is traveling closed. With the help of Jim Simonson of NMFS a flag was added to the gate so that the sensors could be mounted in a dry environment behind the gate. The flag transitions through the bulkhead that the shocks are mounted to. As the gate is traveling closed the PLC is monitoring the state of the sensors. If a Request To Open(RTO) is received while the gate is traveling closed the PLC will move a new travel open time to the travel open timer depending on how many sensors are on. If all three sensors are on a very short time will be moved to the travel open timer. This time is referred to as the quaternary travel open time. If sensors 1 and 2 are on but 3 is off this means the gate has traveled a little further closed so a tertiary travel open time will be moved to the travel open timer. If only sensor 1 is on and 2 and 3 are off a secondary travel open time will be moved to the travel open timer. If all 3 sensors are off the normal travel open time will be moved to the travel open timer. Failure logic has been installed that will remove the sensors from the logic if a sensor is stuck on or missed for more than three complete cycles. A complete cycle constitutes the shutdown timer timing out. If a failure occurs the normal travel open time will be in place for all RTO's, leaving the gate operating like it has in the past. A light will be lit to notify site personnel who will hopefully notify PSMFC. When M4 is in place and the PLCs are upgraded to SLC505's with Ethernet, Web Ports will be added so that we can receive emails of failures.
Troy 12:55, 6 November 2006 (PST)A meeting between the COE, NMFS and PSMFC resulted in the agreement that the GOJ and GRJ gates would be delivered to NMFS Pasco shop for possible sensor research/installation. This meeting took place 10/25/06
A sensor has been added to A Separator gate at LMJ and has been working for ~3 months. Efforts are being made to refine the programming so that it will work at other sites.
Meeting Minutes
LINKS
Pertinent links
