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chara:trouble_shooting [2021/09/28 14:58]
gail_stargazer 		chara:trouble_shooting [2021/09/28 15:02]
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  \\ The GAIN controls the gain of the feedback between the encoder and the drive velocity. A high gain means a "stiffer" response, but can lead to oscillations or fog-horning if it's too high. \\  \\ The Fn controls the maximum frequency of the servo response. A high Fn means higher frequencies are allowed through, which can mean correcting for faster problems but if too high can also lead to oscillations or fog-horning. \\  \\ The software will not make changes to either of these quickly as that is a dangerous thing to do. There is NO POINT to clicking the up or down buttons more than once every few seconds. Indeed it is bad to do so as you will confuse the software. The change between slewing and tracking is also slow for similar reasons. This is why sometimes the "wrong" thing seems to change. It is a sign that you are trying to do things too quickly. \\  \\ Slew and tracking mode work differently, mostly because the speeds are so different. \\  \\ IN SLEWING MODE \\  \\ - If the gain is too low you will overshoot the target. \\  \\ - If the gain is too high it will fog-horn. \\  \\ - If the Fn is too high it will also fog-horn, even at low gains. \\  \\ You need to have the lowest possible gain and Fn in slew mode that doesn't overshoot the target. Fn in slew mode should almost never be higher than 4. If it is, please turn it back down to 4. If you think this is a problem please let Theo know, along with a detailed explanation of what happened. \\  \\ IN TRACKING MODE \\  \\ - If the gain is too low it will keep moving between slewing and tracking. \\  \\ - If the gain is too high it will fog-horn. \\  \\ - The same goes for Fn. \\  \\ In tracking mode you want the highest gain and Fn that allows the telescope to track well without fog-horning. If it "oscillates", which you will see in the green dots of tiptilt oscillating, try turning up the gain, and also try turning down the Fn. \\  \\ Some final remarks: \\  \\ - The gain is temperature dependent, so when the temperature changes these things will change, but more so for tracking. \\  \\ - The tiptilt system almost never causes oscillations, it almost always shows you that the scope is oscillating. If the white dots are centered on tiptilt and the green dots are moving the tiptilt is doing it's job and correcting for scope motion. \\  \\ - If a drive gets disabled at the end of a slew, the gain is too low. At low gain and low velocity the encoder signal changes very slowly or doesn't change at all. After 5 secs the software interprets this as a stall and disables the drive. The tricky part is that increasing the gain to avoid this situation might make the telescope to oscillate during the next slew. So the gain should be low (4 or even 1) during slewing but higher 7 or 10 when the telescope is basically at the target position.  \\ The GAIN controls the gain of the feedback between the encoder and the drive velocity. A high gain means a "stiffer" response, but can lead to oscillations or fog-horning if it's too high. \\  \\ The Fn controls the maximum frequency of the servo response. A high Fn means higher frequencies are allowed through, which can mean correcting for faster problems but if too high can also lead to oscillations or fog-horning. \\  \\ The software will not make changes to either of these quickly as that is a dangerous thing to do. There is NO POINT to clicking the up or down buttons more than once every few seconds. Indeed it is bad to do so as you will confuse the software. The change between slewing and tracking is also slow for similar reasons. This is why sometimes the "wrong" thing seems to change. It is a sign that you are trying to do things too quickly. \\  \\ Slew and tracking mode work differently, mostly because the speeds are so different. \\  \\ IN SLEWING MODE \\  \\ - If the gain is too low you will overshoot the target. \\  \\ - If the gain is too high it will fog-horn. \\  \\ - If the Fn is too high it will also fog-horn, even at low gains. \\  \\ You need to have the lowest possible gain and Fn in slew mode that doesn't overshoot the target. Fn in slew mode should almost never be higher than 4. If it is, please turn it back down to 4. If you think this is a problem please let Theo know, along with a detailed explanation of what happened. \\  \\ IN TRACKING MODE \\  \\ - If the gain is too low it will keep moving between slewing and tracking. \\  \\ - If the gain is too high it will fog-horn. \\  \\ - The same goes for Fn. \\  \\ In tracking mode you want the highest gain and Fn that allows the telescope to track well without fog-horning. If it "oscillates", which you will see in the green dots of tiptilt oscillating, try turning up the gain, and also try turning down the Fn. \\  \\ Some final remarks: \\  \\ - The gain is temperature dependent, so when the temperature changes these things will change, but more so for tracking. \\  \\ - The tiptilt system almost never causes oscillations, it almost always shows you that the scope is oscillating. If the white dots are centered on tiptilt and the green dots are moving the tiptilt is doing it's job and correcting for scope motion. \\  \\ - If a drive gets disabled at the end of a slew, the gain is too low. At low gain and low velocity the encoder signal changes very slowly or doesn't change at all. After 5 secs the software interprets this as a stall and disables the drive. The tricky part is that increasing the gain to avoid this situation might make the telescope to oscillate during the next slew. So the gain should be low (4 or even 1) during slewing but higher 7 or 10 when the telescope is basically at the target position.
  
- \\ {{https://ssl.gstatic.com/ui/v1/icons/mail/images/cleardot.gif?direct&|external image cleardot.gif}}+==== E2 AOB Dichroic Recovery ==== 
 + 
 +{{:chara:files:beaconrecoveryinstructions.pdf|E2 AOB Dichroic Recovery Document}} 
 + 
 +==== E1 Hut and Cooler Communications Recovery ==== 
 + 
 +{{:chara:files:e1_hut_coms_recovery.pdf|E1 HuT and Cooler Communications Recovery}}  \\ 
 +{{https://ssl.gstatic.com/ui/v1/icons/mail/images/cleardot.gif?direct&|external image cleardot.gif}}
  
 ====== Dome issues ====== ====== Dome issues ======
chara/trouble_shooting.txt · Last modified: 2024/06/18 00:21 by charaobs

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