RAIV (Redundant Array of Independent Victors)

[Rapt0r9]

Well, I was considering setting up a relay to select which motor the victor would be assigned to. By using a spike, we can cut the number of victors that we need in half, thus helping to reduce the weight of the robot. The spike can also serve as protection to prevent both victors from outputting voltage to the motor at once.

I was reading up on the dashboard packet structure earlier today and I think that we should defiantly be able to write something that will give the drivers feedback as to why the bot is responding awkwardly. We have always tried to integrate a laptop into our controller to use with dashboard, but we never got around to it.

[Al Skierkiewicz]

Originally Posted by Rapt0r9

Well, I was considering setting up a relay to select which motor the victor would be assigned to. By using a spike, we can cut the number of victors that we need in half, thus helping to reduce the weight of the robot. The spike can also serve as protection to prevent both victors from outputting voltage to the motor at once.

A few things will get in your way on this implementation. The first and foremost, the Spike is only rated for 20 amps. This rating is determined not only by the fuse but by the ratings of the contacts used on the internal relays. If allowed under the rules (and I do not believe under the current rulebook this would be allowed) a stalled FP, or Chalupa motor would turn a Spike into ash in a matter of a few minutes. Certain failure modes of the Victors would produce a dead short on the output, so just wiring in parallel would also cause more harm than good. Finally, custom circuits (i.e. a high current relay) are not allowed, under the rules, to be placed between the Victor and motor nor is a custom circuit allowed to directly control a motor.
Some teams have problems with Victors yet most do not. I could spend a few hours talking about Victor failures but essentially all failures can be reduced to just two causes. 1. Foreign material in the Victor causes internal shorts. Keep metal shavings, gear debris and drill dust out of electronics. 2. Excessive and repeated currents at 100 amps or above caused by drive train design, loose or intermittant elctrical connections, lack of calibration in multimotor systems and improper driving technique. This abuse causes extreme internal heat in the active devices resulting in electrical failure.
I would spend more time trying to deduce which failure mode is causing your Victors to die and correct the problem at the beginning of robot construction. If you have a correctable problem and ignore it, you will reach a point where your backup to the backup will also fail leaving you with a non-functional robot. Murphy says this will occur in the last match on Einstein on Saturday afternoon. I would rather have a functional robot and a medal than three dead Victors.

[Rapt0r9]

In the past we have had problems with cables coming loose from the Victors and Spikes. This has cost us a couple matches and this idea would primarily be in place to prevent this from occurring. It looks like using a spike wouldn't work as Kevin mentioned, but I am still considering using the motor diagnostics, even if it is just for feedback to the drivers.

I was also considering setting up a DPDT switch on the robot and using that to switch the connection of the motor to the victors. Basically the common leads would go to the motor's positive and negative lines and the victors would be connected to the throw leads. The switch can then be actuated by an electrical soleoid which would throw the switch. It is kind of a jimmy rigged relay, but it is a physical relay, so the victors would never be outputting to each other, or to the motor at the same time.

[Al Skierkiewicz]

Again, current rules do not allow custom circuits between the motors and the output of a Victor. Switches must be considered as a custom circuit in my opinion when used in this way. Electrical solenoids are also not allowed under the current rules. I am hoping that this rule will change in the future by having a few solenoids provided as part of the kit.

[MrForbes]

Originally Posted by Rapt0r9

In the past we have had problems with cables coming loose from the Victors and Spikes. This has cost us a couple matches and this idea would primarily be in place to prevent this from occurring.

It seems to me that adding MORE wiring connections is not the best way to solve problems caused by faulty wiring connections.

[EricH]

Originally Posted by squirrel

It seems to me that adding MORE wiring connections is not the best way to solve problems caused by faulty wiring connections.

I concur. Make sure that your PWMs and power wires are secure. Check before every match if you need to. Come up with some way of securing connections before looking into other methods.