Cause it makes flywheel shooters easier and you can’t on a Jag. Now if your lift is underpowered, slap a second motor on and slave the Talon to your primary. You couldn’t use the onboard PID on the Jag anyways if you were planning on driving a system with more than one motor. Setting P, then D, then I while closed loop is live would be pretty terrifying. On the fly gain schedule switching and single frame parameter setting.The PID on the Jag was nigh useless without feedforward and anti-windup. PIDF with automatic and triggerable integral anti-windup.You had to poll the Jag and you could only get feedback for the closed loop mode you were in. Unsolicited position and velocity feedback.The Talon firmware solves SO many problems with using advanced features on the Jag: I skimmed the software manual, and I would like to buy a Mountain Dew or beverage of choice for the people behind the firmware. If you really want the details checkout the Talon user’s guide and Talon software ref manual at…Īlso the FRC screensteps page has lots of good info… This season’s CAN implementation really is a new type of animal. boot-loaders for all new CAN nodes gracefully handle bad firmware files, losing power/CAN in middle of flash, flashing wrong product firmware, etc… The roboRIO web-based configuration will tell you when you have multiple CAN nodes with the same devID and will let you fix it without isolating one CAN node. With the new lightening tab in the DS you can grab the CAN bus utilization (%) and error counts. With the terminating resistor built into the roboRIO and PDP there is no risk of manually soldering resistors or hand-crimping them and not being sure they are actually in-circuit. With weidmuller connectors, there is no risk of bad crimps or bad connectors. With the Talon SRX specifically, we took the lessons learnt from seasons past to make the CAN use-case a lot more robust and painless. I’ll readily admit the using CAN before this year was rather more complicated, since you needed to make up the correct RJ11 cables, terminate the bus correctly, make up a (correct) serial-RJ11 adapter, and (shudder) deal with BDC Comm for assigning IDs and testing. Now that all the the assignment happens on the roboRIO webpage, I think it’s only a little more complicated than wiring up a dozen PWMs to the correct ports. And you have to assign the correct ID to any Talon you have to replace for some reason. The only mandatory complication with CAN is that you initially have to assign a unique address to each Talon, PDP, and PCM on the CAN bus. To be fair, most of those complications you mention are completely optional. If you use PWM though, I think you CAN (pun intended) get those functionalities, but with a little more work. With CAN you can configure it to take speed commands (RPM), distance commands (Rotations), Percentages (-1.0 - 1.0), and others. With PWM you just give it a -1.0 - 1.0 value. So, using CAN on Jaguar or Talon SRX to use this has some benefits.ĬAN is definitely more complicated than PWM, which is extremely simple. In fact, I’d argue that if there wasn’t an advantage of using closed loop control via CAN, the smart folks at Cross the Road Electronics wouldn’t have made the Talon SRX. On Jaguar, this now happens at 1 kHz.Īdvantage 1 (above) gets reduced every time more processing power, memory, etc. The motor controller reads the sensor (directly), performs the PID computation, and updates the output to the motor. The loop rate of the PID on the motor controller can be higher since there is no communication delay.Less processing run on the main robot controller means more cycles for other things.The idea behind supporting closed loop control via CAN was to have the sensor (encoder, potentiometer, limit switch, etc.) directly connected to the motor controller so that the processing power of the CPU (MCU) within the motor controller could be harnessed to do the control loop (PID). One object or two - not much of a big difference from programming standpoint. So, if you have to have an encoder anyway, then really the CAN mode Jaguar is not much better in terms of what it can do.
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