Hi! I just built the AR4 and I can't calibrate any of the joints. If I hit Auto Calibrate, visually it calibrates fine, but log says Auto Calibration Failed a few seconds after I hit it, despite it finishing the sequence. Similar things are happening on all joints individually.
If I stop for example J3 from jogging, I get no errors and the joint doesn't recover or position itself correctly after that so it loses the position similar to open loop behavior, despite it supposedly being in closed loop.
It behaves in the same way across 3 pcs running windows 10 and windows 11.
The log doesn't indicate what is actually wrong unfortunately, and I can't do any serial monitoring as far as I know since the teensy needs to be communicating with the AR4 software.
If I run the program "test encoders" everything seems to be working. But if I power the drivers/motors then I get no readings from J3 encoder while running test encoders. J3 also has very jerky motion when jogging.
What's wrong here and how do I fix it?
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The VIN or 5v terminal is correct.
@chris-annin yes. Encoders work like expected if motor drivers aren't powered. J3 encoder goes out when they're powered.
@chris-annin It does calibrate normally in motion regardless of if encoders are active or not, but I get error messages about failed calibration.
It sounds like there may be a few issues going on here and they may or may not be related. Lets start with the calibration. When you autocalibrate and it says calibration failed are there any related messages In the error log? can you calibrate any joint individually - if you click calibrate J1 will that joint calibrate by itself? When you run the program for check calibration does the value for J1 toggle from 0 to 1 when you depress the J1 limit switch?
I get no additional errors in the log.
Each joint fails individually when calibrating individually. Though they complete their movements so visually it looks like it's working.
All limit switches work as intended, going from 0 to 1 when depressed.
When the autocalibration finishes and you get the failed message what position is the robot arm in? After auto calibrating is there a message in the "last response from controller" field on the settings tab? also you mentioned in your email that there seem to be issues when the drivers are powered on but not when they are powered off. When you run the check limit switches program are the drivers powered on or off? is there a difference in the response from the check limit switches program when the drivers are powered on vs powered off?
Hello Olaf & Chris,
I just finished building my arm and I get the same 'calibration failed' once I updated to AR4 HMI interface V1.2
Calibrating in V1.1 works fine and I get a calibration successful message.
I suspect there might be an issue in the code somewhere?
In addition I can jog the robot and everything works as expected until I start to use the Rx, Ry, Rz, Tx, Ty, Tz, and Trx, Try, Trz jogs. The robot starts moving in crazy positions or just says 'position out of reach'. any ideas what could be causing this? I have not done a fine tune on the arm yet but it is pretty close.
Cheers,
J
I ran the exe file on another PC and was able to replicate the issue getting calibration failed. Doing a little research it looks like opening a serial connection with the timeout parameter (which I added in V1.2) can cause issues with the response message which was triggering the failed alarm. I have uploaded V1.3 to the downloads page. Please give that a try. I apologize for this issue.
Calibration was successful with 1.3, issue with J3 was a loose pulley due to no key being inserted. Thanks for the quick update Chris! You're a star.
Only issue now is this probably abnormal offset on J5? Having issues with getting the limit switch to trigger reliably and getting the offset smaller. Can't really get further than this.
@olof-ogland can you email me a quick video of your robot performing a J5 single axis calibration, I would like to get a look at how it behaves and what angles its going to.
The new V1.3 calibrated successfully for me. Thanks Chris.
