Difference between revisions of "Granity user guide/Machine"

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(Motor parameters)
(Position feedback device)
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If limited motion range and [[Tracking error|tracking error fault]] after certain travel distance is observed, try dividing this parameter value by 4 or multiplying by 4.
 
If limited motion range and [[Tracking error|tracking error fault]] after certain travel distance is observed, try dividing this parameter value by 4 or multiplying by 4.
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If using '''SinCos''' feedback device, multiply encoder line count by the selected interpolation factor and enter it as the feedback device resolution. I.e. if SinCos encoder has 1024 lines/sincos cycles per revolution, and you are using 64X interpolation, then set FBR as 1024*64=65536 PPR.
 
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| FBI || Invert feedback direction || Set polarity of feedback device counting direction || Motor and feedback device must have same electrical positive rotation direction to make a stable servo system. If your system shows no stability (instant following error after a motor "jump"), try changing this setting.
 
| FBI || Invert feedback direction || Set polarity of feedback device counting direction || Motor and feedback device must have same electrical positive rotation direction to make a stable servo system. If your system shows no stability (instant following error after a motor "jump"), try changing this setting.

Revision as of 21:44, 3 May 2015

GranityMachine.png

The Machine tab serves following purposes:

  • Choose axis type (linear/rotary) and its scale
  • Set motor type and properties
  • Set feedback device types and properties

Parameters

Axis mechanics

Short GUI name GUI name Description How to use
AXT Axis type & units Select axis type and real world units used Choose your mechanical axis type here. AXT and AXS affect only the unit conversion of Granity parameters (such as accel/velocity limit unit conversions), no effect on drive operation.
AXS Axis scale Set axis travel per motor revolution Determine how much your axis moves per revolution and enter it here. I.e. if you have selected Linear[mm] as AXT, then calculate and enter how many millimeters axis moves per revolution. AXT and AXS affect only the unit conversion of Granity parameters (such as accel/velocity limit unit conversions), no effect on drive operation.
AXI Invert direction Set the positive direction of axis State of this checkbox determines which rotation/travel direction is positive and which negative. Change this to invert the direction of axis.

Motor parameters

Short GUI name GUI name Description How to use
MT Motor type Motor type to be driven Choose your motor type.
MPC Pole count Set motor magnetic pole count (not in DB motors) Set number of magnetic poles present in the AC/BLDC motor according to motor specifications. If not specified, see Determining motor pole count or in case of linear motor, see Configuring linear servo motor.
MCC Continuous current limit Motor continuous current limit (peak value of sine in AC/BLDC modes, not RMS) Use value from your motor data sheet or any lower value to reduce torque. If your AC/BLDC motor phase current is specified as RMS value, then multiply it with 1.41 to get peak value of sine.
MMC Peak current limit Motor peak current limit (peak value of sine in AC/BLDC modes, not RMS). Drive outputs this current to motor for max of 2 second duration and then falls back to the continuous limit (MCC). MCC will be also used if motor temperature modeling (see MTC) indicates maximum temperature.
MR Coil resistance Motor phase-to-phase winding resistance See motor data sheet and enter the value here. If unknown, see Tuning torque controller.
ML Coil inductance Motor phase-to-phase winding inductance
MTC Thermal time constant Motor thermal time constant value in seconds, used for thermal modeling of motor to avoid motor overheating with peak current (MMC) Refer to your motor data sheet for correct value.

If not available, use formula 200*motor_weight (kg) as approximate, so a 2 kg motor would get a 400 second time constant. There is no guarantee of accuracy of this method.

Position feedback device

Short GUI name GUI name Description How to use
FBD Feedback device Position feedback device type attached to the axis Choose connected device type. Use only the ones that are currently supported in the firmware. Currently only Quadrature encoder 1 is supported.
FBR Feedback device resolution Resolution of the feedback device per revolution In case of quadrature encoder choose number of lines or pulses per revolution. Make sure to enter resolution of feedback device before 4x quadrature decoding (encoder real resolution is 4 times the number of lines per revolution).

If limited motion range and tracking error fault after certain travel distance is observed, try dividing this parameter value by 4 or multiplying by 4.

If using SinCos feedback device, multiply encoder line count by the selected interpolation factor and enter it as the feedback device resolution. I.e. if SinCos encoder has 1024 lines/sincos cycles per revolution, and you are using 64X interpolation, then set FBR as 1024*64=65536 PPR.

FBI Invert feedback direction Set polarity of feedback device counting direction Motor and feedback device must have same electrical positive rotation direction to make a stable servo system. If your system shows no stability (instant following error after a motor "jump"), try changing this setting.
FBH Hall sensors Configure Hall sensors if available If motor Hall sensors are connected and wires, choose option from the list to utilize them.