Quote:
Originally Posted by Daniel_LaFleur
Dr Joe,
The Jags aren't as fragile as some put them out to be. Here in FIRST we tend to ABUSE speed controllers rather than use them.
That being said, there are a few areas where the Jags need to be made better:
1> CAN control -- The Can-bus and its related connectors tend to be ... touchy. A better positive lock and more robust pin setup would help things immensly.
2> Failure reporting -- The Jag has plenty of processing power. It needs to report exactly what the failure is, not just a flashing LED, so that our control system may deal with said failure.
3> For some reason the Jag seems to be a swarf magnet. Possibly adding a filter to the air intakes would help.
4> Protection from reverse power and reversed input/output. At least create connections that are physically different so that you cannot reverse input and outout wires ... and somehow protext from reversed input power (I havent looked at the schematic to determine an easy one here).
All this being said ... with proper care and feeding ... Jags are a good speed controller and they offer many benifits that the Victors do not.
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As I stated earlier, I tend to agree that the Jaguars are not well suited to our uses. I find their over-current protection to be overly touchy, but not so touchy that I would dismiss repeated shutdowns without at least analyzing the performance of the system.
In general I don't like my electronics 'helping me' unless I specifically ask them to, including a fixed, sensitive over-current shutdown. As a feature I think it's excellent, but it should be configurable, or at least something that can be enabled or disabled by jumper/CAN.
In my (bad) experience, the Jaguars are no more swarf loving than Victors, and I mean that in that our Victors tend to blow up from swarf (I'm really amused by that word) as often as our Jags. In general I think teams might just be getting worse about swarfing (seriously, it's fun to say) around the controllers.
I would like to see a variety of improvements to the CAN system, including better failure reporting, and an internal software switchable terminator, or even just a jumper we could put in place on the Jag(s) at the end of the line to terminate it. I actually don't have much a problem with the existing physical interface, other than that I seem to have a terrible track record with crimping.
Reverse power protection is a pet project of many people, even I'm toying with it, it's really difficult problem given the currents and voltage we're dealing with here.
Bottom line, the Jags have potential, and we do use them primarily for drive systems (because of the internal encoder support -- which I'm on the fence about) but that is all, I find they are not as robust as Victors, and I find they are
not sufficiently polished... yet, but they're rapidly getting there. I think a lot of their 'great features' are as of yet under developed and are more novelty than useful tool.
Also, swarf. Swarfing swarf. (Really, try to say it out loud with a straight face)
Matt