Greetings all; I now have a nominally 180 degree cam on the BS-1 home switch.
And I have jerk it out by the roots accel's set, like 3000. Got the new scope hooked to the pwmgens outputs so I can get an idea of how hard the driver is hitting the motor. And I have found with this driver, that I can turn it either direction hard enough to turn an input on solidly for several seconds without accumulating enough error to stop it, and I am getting someplace as that is 1800 degrees/minute on the dro. About 10x faster than I started with 2 hours ago. But the accel's are glacial! Setting the job slider to 1800 an pressing the jog key, it takes all of 5 seconds for the pwmgen to reach 100% on for output. Take my finger off the key, and it coasts for 5-7 seconds, but the motor is doing exactly what the pwmgen is telling it to do, the pwmgen gradually decays toward a 0% duty cycle, it is not dropping to zero the instant I lift my finger, which IMO, it should. Initiate a home operation from halfway around the dial, and it hits about a 50% pwmdrive in 3 or 4 seconds, then sails by the switch about 45 degrees before the pwm decays to zero and then reverses direction, and it slowly oscillates, hunting for the switch running past it with a decreasing run by until it finally switches to LATCH_VEL after 4 or 5 cycles, finds the switch one last time, then drives to HOME_OFFSET about 4 degrees away, settling on something in the area of .0150 degrees of error, not enough to run the motor & leaving the pwmgen at 8% or so. Where is the lowpass filter? I have no limiters other than the pid_a.maxoutput currently set at 800 so its out of the way. The only thing I see as odd in the pid_a config is that in order to get a near null error at cruising speed, it takes an FF1 param in the 22.5 range. # Axis A #******************** [AXIS_A] MAX_VELOCITY = 30.000 MAX_ACCELERATION = 3000.00 [JOINT_3] TYPE = ANGULAR HOME = 0.0 #HOME_SEQUENCE = 3 HOME_SEARCH_VEL = 20 HOME_LATCH_VEL = -3.0 HOME_FINAL_VEL = 10 HOME_OFFSET = 4.498500 # is a servo, with real encoder and does not lose home! #VOLATILE_HOME = 0 FERROR = 2.50 MIN_FERROR = 0.250 MAX_VELOCITY = 30.000 MAX_ACCELERATION = 3000.00 P = 2000 I = 0.0250 D = 0.0250 FF0 = 0 FF1 = 22.65 FF2 = 0.005 BIAS = 0 DEADBAND = 0.00015 BACKLASH = .001 MAX_OUTPUT = 800.0000 IDB_AMOUNT = 9.5 SERVO_SCALE = 666.6666666666667 PWMGEN_TYPE = 2 #********** This is a position servo, joint_3-vel-cmd is not connected. joint_3-position-command shows exactly the extremely slow response I am observing at the pwmgen's, with a slow curve leading to a straight ramp, take finger off key and it rounds off to a final value. Slowly...... Call me puzzled, frustrated, dumb even. Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) If we desire respect for the law, we must first make the law respectable. - Louis D. Brandeis Genes Web page <http://geneslinuxbox.net:6309/gene> _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
