Difference between revisions of "Axis Setup Procedure"

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== Introduction==
+
{{Languages|Axis_Setup_Procedure}}
This series of slides will explain how to create and set an axis in the softMC controller. For that you will need:
+
The steps below explain how to create and define an axis in the softMC controller.  
  
* Running softMC (either a real, or virtual)
+
The following are required:
* User interface (Control.Studio)
+
* Running softMC (actual or simulated)
 +
* User interface (ControlStudio)
  
== Step #1: declare axis ==
 
 
In the first line of CONFIG.PRG file write the number of axes that will be in use:
 
  
 +
== Step 1: Declare Axis ==
 +
In the first line of CONFIG.PRG file specify the number of axes that will be in use:
 
<pre>
 
<pre>
 
Sys.Naxes = <number>
 
Sys.Naxes = <number>
Line 17: Line 17:
 
</pre>
 
</pre>
  
 
+
Send the CONFIG.PRG file to softMC and run it by issuing these two lines from terminal window:
Send this file to MC and run it by issuing these two lines from terminal window:
 
 
<pre>
 
<pre>
 
send config.prg
 
send config.prg
Line 24: Line 23:
 
</pre>
 
</pre>
  
Now you have your axes defined, it is easily to check issuing this command from terminal window:
+
Now you have your axes defined, it is easy to check by issuing this command from terminal window:
 
<pre>
 
<pre>
 
->?axislist
 
->?axislist
Line 30: Line 29:
 
</pre>
 
</pre>
  
== Step#2: Setting user friendly axis name ==
+
== Step 2: Define Meaningful Axis Name ==
 
+
System default axis names are not very user friendly (a1,a2,a3, etc.).
System default axis name are not very user friendly (a1,a2,a3, )  
+
It is a good practice to give them more meaningful names. This is done in CONFIG.PRG file only, by assigning a new name to each axis (no double-quotes) to [[MC-Basic:axis.AXISNAME|<axis>.AxisName]] property.
It is a good practice to rename them into something more meaningful. This is done in CONFIG.PRG file only , assigning to each axis now name (no double quotes sign) to [[MC-Basic:axis.AXISNAME|<axis>.AxisName]] property.
 
 
 
 
 
 
 
 
<pre>
 
<pre>
 
Sys.Naxes = <number>
 
Sys.Naxes = <number>
Line 43: Line 38:
 
a1.AxisName = Xaxis
 
a1.AxisName = Xaxis
 
a2.AxisName = Lift
 
a2.AxisName = Lift
….
+
 +
End Program
 +
</pre>
 +
 
 +
== Step 3: Prepare General Axis Setup ==
 +
To setup system axes, a setup program must be prepared. Let’s call it SETUP.PRG.<br/>
 +
'''Note''':<br/>
 +
* To access (write to) an axis property, the axis needs to be attached.
 +
* For some properties, the axis needs to be disabled.
 +
 
 +
'''SETUP.PRG'''
 +
<pre>
 +
Program
 +
Call SetAxis(a1)
 +
Call SetAxis(a2)
 +
 
End Program
 
End Program
 +
 +
Sub SetAxis(ax as generic axis)
 +
With ax
 +
Attach
 +
En = 0
 +
 +
<stuff goes here>
 +
 +
Detach
 +
End With
 +
End Sub
 +
 
</pre>
 
</pre>
 +
 +
==Step 4: Position Units Definition==
 +
[[Image:GearMotor.png|GearMotor.png]]
 +
 +
[[MC-Basic:axis.POSITIONFACTOR|<axis>.PositionFactor]] defines the position units that will be used in all position variables of the specified axis  (pcmd, pfb, etc.). It consists of the following:
 +
 +
* Motor encoder resolution seen through the motion bus (See EtherCAT, SERCOS, CanOPEN). How many counts are there in one motor revolution - stored in pos_units global variable (for each axis differently).
 +
* Gear ratio (M:N) and/or the pitch of the linear screw  (mm/rev).
 +
 +
:*Rotary axes:
 +
::For position in degrees PositionFactor is:PFAC = Pos_Units *(M/N)/360
 +
 +
:*Linear axes:
 +
::For position in millimeters PositionFactor is:PFAC = Pos_Units)/MPITCH
 +
 +
[[Image:LinMotor.png|LinMotor.png]]
 +
 +
See Motion Bus setup for pos_units and MPITCH setup
 +
 +
==Step 5: Direction of Movement ==
 +
Positive direction of drive's position increments does not have to match the desired positive direction of user axis (Upwards, Left-Right, Counterclockwise). Therefore <axis>.direction flag is to be used:
 +
<pre>
 +
<axis>.Direction = {1|-1}
 +
</pre>
 +
 +
Value of '''-1''' indicates direction inversion.
 +
 +
==Step 6: Velocity, Acceleration, Jerk Units ==
 +
Velocity/acceleration/jerk units do not have to match position units. Units can be user-defined. For all the derivative units (velocity, acceleration, jerk), the default time scale is in milliseconds; therefore scaling is needed.
 +
 +
To use position units per second for velocity, the following must be defined:
 +
<pre>
 +
<axis>.VelocityFactor = <axis>.PositionFactor/1000
 +
</pre>
 +
In this case if the user sets the position in millimeters the velocity will be '''mm/sec'''
 +
 +
To define velocity in '''RPM''' of the motor:
 +
<pre>
 +
<axis>.VelocityFactor = Pos_Units /1000/60
 +
</pre>
 +
 +
Acceleration and jerk units are the same; their default values are expressed in velocity and acceleration units per milliseconds. Thus, in order to set them per seconds, they need to be set as:
 +
<pre>
 +
<axis>.AccelerationFactor = <axis>. VelocityFactor /1000
 +
<axis>.JerkFactor        = <axis>. AccelerationFactor /1000
 +
</pre>
 +
 +
==Step 7: Units Summary==
 +
Position, velocity, acceleration and jerk units are set by:
 +
<pre>
 +
<axis>.PositionFactor = …
 +
<axis>.Direction = …
 +
<axis>.VelocityFactor = …
 +
<axis>.AccelerationFactor = …
 +
<axis>.JerkFactor = …
 +
</pre>
 +
 +
==Step 8: Position Limits==
 +
Setting  position range of an axis.
 +
Setting maximum position:
 +
<axis>.Pmax = … and enabling /disabling it: <axis>.PmaxEn = {0|1}
 +
Setting minimum position:
 +
<axis>.Pmin = … and enabling /disabling it: <axis>.PminEn = {0|1}
 +
Setting the axis type:
 +
<axis>.AxisType = 0 ‘ For linear axes
 +
<axis>.AxisType = 1 ‘ For rotary axes
 +
For rotary axes rollover can be defined:
 +
Enabling/Disabling it:
 +
<axis>.PositionRollOverEnable  = {0|1}
 +
Setting the whole range:
 +
<axis>. PositionRollOver
 +
Setting the low value:
 +
<axis>. PositionRollOverMin
 +
 +
Note: If the enable flag is not set, the corresponding value does not need to be set.
 +
 +
[[Image:Axis-PLIM.PNG|500px]]
 +
 +
==Step 9: Motion Bus Units ==
 +
Depending on the type of motion bus (EtherCAT, SERCOS, CANopen) and drive used, several parameters are available for the user to adjust (but are not necessarily needed):
 +
 +
If micro-interpolation is turned on in the drive, the velocity sent to drive must be properly scaled; this is done with (for counts per ms):
 +
<pre>
 +
<axis>.MotionBusVelocityScale = 0
 +
<axis>.MotionBusVelocityBase = 1
 +
</pre>
 +
If a limited drive’s position range is used (other then integer 32 bits):
 +
<pre>
 +
<axis>.CountMin = <drive min position value>
 +
<axis>.CountMax = <drive max position value>
 +
</pre>
 +
 +
==Step 10: Motion Parameters==
 +
Motion parameters are grouped into velocity, acceleration and jerk values. All have maximum values for overall limitations, and motion-default values that are used when motion is executed.
 +
 +
{| class="wikitable" margin-left: 10px; color: red; border-style: solid; border-width: 3px"
 +
| Motion default value is:
 +
| [[MC-Basic:element.VELOCITYCRUISE|'''<axis>.VelocityCruise''']]
 +
|}
 +
 +
Velocity is set according to maximum axis physical limit (drives/motor capabilities and mechanical limitations):
 +
  <axis>.Vmax
 +
 +
{| class="wikitable" margin-left: 10px; color: red; border-style: solid; border-width: 3px"
 +
| Motion default values are:
 +
| [[MC-Basic:element.ACCELERATION|'''<axis>.Acceleration''']] <br> [[MC-Basic:element.DECELERATION|'''<axis>.Deceleration''' ]]
 +
|}
 +
Acceleration is set according to maximum axis physical limits (Max drive/motor current, axis load) in user units:
 +
  <axis>.Amax
 +
  <axis>.Dmax
 +
 +
{| class="wikitable" margin-left: 10px; color: red; border-style: solid; border-width: 3px"
 +
| Motion default value is:
 +
| [[MC-Basic:element.JERK|'''<axis>.Jerk''']]
 +
|}
 +
Jerk  is the third time-derivation of position, if smooth profiles are used it needs to be defined a good rule of thumb is to set J=BW*A, where J – jerk, A – acceleration, BW- control Bandwidth (Hz).
 +
  <axis>.JerkMax
 +
 +
==Step 11: Safety Parameters==
 +
Maximum allowed position error (PE). PE is defined as a difference between the position command and position feedback. Due to communication delay of the motion bus and processing time of the drive (micro-interpolation) position command of the several samples before the current is compared to the currently obtained position feedback of the drive:
 +
  <axis>.PositionErrorMax – max allowed position error during in user units.
 +
  <axis>.PositionErrorDelay – number of samples used for delay computation.
 +
 +
Velocity (Runaway) Protection, the feedback velocity of the motor is checked every sample (recommended to be set to 120% of the <axis>.VelocityMax)
 +
  <axis>.VelocityOverSpeed
 +
 +
Sanity Threshold, as a final protection against unintentional jumps (recommended to be set to 1000% of <axis>.VelocityMax):
 +
  <axis>.VelocitySafetyLimit
 +
 +
Torque Error – only if axis dynamic model is turned on
 +
  <axis>.TorqueMaxError
 +
 +
==Step 12: Smoothness==
 +
 +
Different profile types are available, ranging from very smooth S-curves (Trapezoidal Acceleration, Sine Acceleration) to less smooth but faster Trapezoidal Velocity, to totally edgy profiles (Constant Velocity) by setting these two parameters:
 +
:<axis>.Smooth defined automatic (0-100) or manual smoothing (-1)
 +
:<axis>.PrfType specifies profile more precisely (Trapezoidal Velocity, Trapezoidal Acceleration, Sine Acceleration)
 +
 +
==Step 13: Axis Setup - Complete Example: the SetAxis Subroutine==
 +
 +
<pre>
 +
sub SetRotAxis(ax as generic axis, byval minval as double , byval maxval as double)
 +
  with ax
 +
    attach
 +
      En = 0
 +
      AxisType = 1
 +
      PositionFactor = pos_unit/360
 +
      VelocityFactor = PositionFactor /1000
 +
      AccelerationFactor = VelocityFactor /1000
 +
      Jerkfactor = AccelerationFactor /1000
 +
      VelocityMax = 1000
 +
      AccelerationMax = 10000
 +
      DecelerationMax= 10000
 +
      JerkMax = 20*amax
 +
      VelocityCruise = 0.5*VelocityMax
 +
      Acceleration = AccelerationMax
 +
      Deceleration = DecelerationMax
 +
      Jerk = JerkMax
 +
      PrfType = -1
 +
      Smooth = -1
 +
      VelocityOverspeed = 1.2*VelocityMax
 +
      VelocitySafetyLimit = 10*VelocityMax
 +
      PositionErrorDelay = 2
 +
      PositionErrorMax  = 1
 +
      PositionMax = maxval
 +
      PositionMin = minval
 +
      PositionMaxEn = 1
 +
      PositionMinEn = 1
 +
      PositionRolloverEnable = 0
 +
  detach
 +
  end with
 +
end sub
 +
</pre>
 +
==Step 14: Motion Bus EtherCAT Example ==
 +
 +
Position Units
 +
:First read the motor encoder resolution (MENCRES – SDO:0x20F1:0)
 +
::MENCRES      =  EC_SDO_READ(<addr>,0x20f1,0)
 +
 +
Then set (value of 1) the configured number of motor shaft revolutions and number of driving shaft revolutions. The gear ratio is calculated by the following:
 +
:Fieldbus CANopen Gear Motor Shaft Scaling  (FBGMS – SDO0x2091:0)
 +
:Fieldbus CANopen Gear Driving Shaft Scaling (FBGDS – SDO0x2091:1)
 +
::gear ratio = FBGMS / FBGDS
 +
 +
==Step 15: Extra - Dynamic Model ==
 +
 +
Torque Scaling
 +
:<axis>.TorqueFactor – according to the Motor KT parameter
 +
 +
Limits
 +
:<axis>.TorqueMax – maximum motor torque
 +
 +
Dynamic Model  Parameters
 +
:axis.DYNAMICMODEL[..] = <…>

Latest revision as of 09:38, 13 September 2017

Language: English  • 中文(简体)‎

The steps below explain how to create and define an axis in the softMC controller.

The following are required:

  • Running softMC (actual or simulated)
  • User interface (ControlStudio)


Step 1: Declare Axis

In the first line of CONFIG.PRG file specify the number of axes that will be in use:

Sys.Naxes = <number>
…
Program
…
End Program

Send the CONFIG.PRG file to softMC and run it by issuing these two lines from terminal window:

send config.prg
reset all

Now you have your axes defined, it is easy to check by issuing this command from terminal window:

->?axislist
A1,A2,A3,A4,A5,A6,A7,A8,A9,A10,A11,A12,A13,A14,A15,A16,A17

Step 2: Define Meaningful Axis Name

System default axis names are not very user friendly (a1,a2,a3, etc.). It is a good practice to give them more meaningful names. This is done in CONFIG.PRG file only, by assigning a new name to each axis (no double-quotes) to <axis>.AxisName property.

Sys.Naxes = <number>
…
Program
	a1.AxisName = Xaxis
	a2.AxisName = Lift
…
End Program

Step 3: Prepare General Axis Setup

To setup system axes, a setup program must be prepared. Let’s call it SETUP.PRG.
Note:

  • To access (write to) an axis property, the axis needs to be attached.
  • For some properties, the axis needs to be disabled.

SETUP.PRG

Program
	Call SetAxis(a1)
	Call SetAxis(a2)	
	…
End Program

Sub SetAxis(ax as generic axis)
With ax
	Attach
		En = 0
		…
		<stuff goes here>
		…
	Detach
End With
End Sub

Step 4: Position Units Definition

GearMotor.png

<axis>.PositionFactor defines the position units that will be used in all position variables of the specified axis (pcmd, pfb, etc.). It consists of the following:

  • Motor encoder resolution seen through the motion bus (See EtherCAT, SERCOS, CanOPEN). How many counts are there in one motor revolution - stored in pos_units global variable (for each axis differently).
  • Gear ratio (M:N) and/or the pitch of the linear screw (mm/rev).
  • Rotary axes:
For position in degrees PositionFactor is:PFAC = Pos_Units *(M/N)/360
  • Linear axes:
For position in millimeters PositionFactor is:PFAC = Pos_Units)/MPITCH

LinMotor.png

See Motion Bus setup for pos_units and MPITCH setup

Step 5: Direction of Movement

Positive direction of drive's position increments does not have to match the desired positive direction of user axis (Upwards, Left-Right, Counterclockwise). Therefore <axis>.direction flag is to be used:

<axis>.Direction = {1|-1}

Value of -1 indicates direction inversion.

Step 6: Velocity, Acceleration, Jerk Units

Velocity/acceleration/jerk units do not have to match position units. Units can be user-defined. For all the derivative units (velocity, acceleration, jerk), the default time scale is in milliseconds; therefore scaling is needed.

To use position units per second for velocity, the following must be defined:

<axis>.VelocityFactor = <axis>.PositionFactor/1000

In this case if the user sets the position in millimeters the velocity will be mm/sec

To define velocity in RPM of the motor:

<axis>.VelocityFactor = Pos_Units /1000/60

Acceleration and jerk units are the same; their default values are expressed in velocity and acceleration units per milliseconds. Thus, in order to set them per seconds, they need to be set as:

<axis>.AccelerationFactor = <axis>. VelocityFactor /1000
<axis>.JerkFactor        = <axis>. AccelerationFactor /1000

Step 7: Units Summary

Position, velocity, acceleration and jerk units are set by:

<axis>.PositionFactor = …
<axis>.Direction = …
<axis>.VelocityFactor = …
<axis>.AccelerationFactor = …
<axis>.JerkFactor = …

Step 8: Position Limits

Setting position range of an axis. Setting maximum position:

<axis>.Pmax = … and enabling /disabling it: <axis>.PmaxEn = {0|1}

Setting minimum position:

<axis>.Pmin = … and enabling /disabling it: <axis>.PminEn = {0|1}

Setting the axis type:

<axis>.AxisType = 0 ‘ For linear axes
<axis>.AxisType = 1 ‘ For rotary axes

For rotary axes rollover can be defined: Enabling/Disabling it:

<axis>.PositionRollOverEnable  = {0|1}

Setting the whole range:

<axis>. PositionRollOver

Setting the low value:

<axis>. PositionRollOverMin

Note: If the enable flag is not set, the corresponding value does not need to be set.

Axis-PLIM.PNG

Step 9: Motion Bus Units

Depending on the type of motion bus (EtherCAT, SERCOS, CANopen) and drive used, several parameters are available for the user to adjust (but are not necessarily needed):

If micro-interpolation is turned on in the drive, the velocity sent to drive must be properly scaled; this is done with (for counts per ms):

<axis>.MotionBusVelocityScale = 0
<axis>.MotionBusVelocityBase = 1

If a limited drive’s position range is used (other then integer 32 bits):

<axis>.CountMin = <drive min position value>
<axis>.CountMax = <drive max position value>

Step 10: Motion Parameters

Motion parameters are grouped into velocity, acceleration and jerk values. All have maximum values for overall limitations, and motion-default values that are used when motion is executed.

Motion default value is: <axis>.VelocityCruise

Velocity is set according to maximum axis physical limit (drives/motor capabilities and mechanical limitations):

 <axis>.Vmax 
Motion default values are: <axis>.Acceleration
<axis>.Deceleration

Acceleration is set according to maximum axis physical limits (Max drive/motor current, axis load) in user units:

 <axis>.Amax
 <axis>.Dmax
Motion default value is: <axis>.Jerk

Jerk is the third time-derivation of position, if smooth profiles are used it needs to be defined a good rule of thumb is to set J=BW*A, where J – jerk, A – acceleration, BW- control Bandwidth (Hz).

 <axis>.JerkMax

Step 11: Safety Parameters

Maximum allowed position error (PE). PE is defined as a difference between the position command and position feedback. Due to communication delay of the motion bus and processing time of the drive (micro-interpolation) position command of the several samples before the current is compared to the currently obtained position feedback of the drive:

 <axis>.PositionErrorMax – max allowed position error during in user units.
 <axis>.PositionErrorDelay – number of samples used for delay computation.

Velocity (Runaway) Protection, the feedback velocity of the motor is checked every sample (recommended to be set to 120% of the <axis>.VelocityMax)

 <axis>.VelocityOverSpeed

Sanity Threshold, as a final protection against unintentional jumps (recommended to be set to 1000% of <axis>.VelocityMax):

 <axis>.VelocitySafetyLimit

Torque Error – only if axis dynamic model is turned on

 <axis>.TorqueMaxError

Step 12: Smoothness

Different profile types are available, ranging from very smooth S-curves (Trapezoidal Acceleration, Sine Acceleration) to less smooth but faster Trapezoidal Velocity, to totally edgy profiles (Constant Velocity) by setting these two parameters:

<axis>.Smooth defined automatic (0-100) or manual smoothing (-1)
<axis>.PrfType specifies profile more precisely (Trapezoidal Velocity, Trapezoidal Acceleration, Sine Acceleration)

Step 13: Axis Setup - Complete Example: the SetAxis Subroutine

sub SetRotAxis(ax as generic axis, byval minval as double , byval maxval as double)
  with ax
    attach
      En = 0
      AxisType = 1
      PositionFactor = pos_unit/360
      VelocityFactor = PositionFactor /1000
      AccelerationFactor = VelocityFactor /1000
      Jerkfactor = AccelerationFactor /1000
      VelocityMax = 1000
      AccelerationMax = 10000
      DecelerationMax= 10000
      JerkMax = 20*amax
      VelocityCruise = 0.5*VelocityMax
      Acceleration = AccelerationMax 
      Deceleration = DecelerationMax
      Jerk = JerkMax 
      PrfType = -1
      Smooth = -1
      VelocityOverspeed = 1.2*VelocityMax
      VelocitySafetyLimit = 10*VelocityMax
      PositionErrorDelay = 2
      PositionErrorMax  = 1
      PositionMax = maxval
      PositionMin = minval
      PositionMaxEn = 1
      PositionMinEn = 1
      PositionRolloverEnable = 0
   detach
  end with
end sub

Step 14: Motion Bus EtherCAT Example

Position Units

First read the motor encoder resolution (MENCRES – SDO:0x20F1:0)
MENCRES = EC_SDO_READ(<addr>,0x20f1,0)

Then set (value of 1) the configured number of motor shaft revolutions and number of driving shaft revolutions. The gear ratio is calculated by the following:

Fieldbus CANopen Gear Motor Shaft Scaling (FBGMS – SDO0x2091:0)
Fieldbus CANopen Gear Driving Shaft Scaling (FBGDS – SDO0x2091:1)
gear ratio = FBGMS / FBGDS

Step 15: Extra - Dynamic Model

Torque Scaling

<axis>.TorqueFactor – according to the Motor KT parameter

Limits

<axis>.TorqueMax – maximum motor torque

Dynamic Model Parameters

axis.DYNAMICMODEL[..] = <…>