HeightInspect Object

The HeightInspect object is a force guide object used to move the robot to the specified direction, and detect the contacted point contacted with a specified amount of force.
image

The diagram above provides a visual representation of a HeightInspect object. Executed from a non-contact state, moves to the direction depicted by the white arrow, and stop at the contacted point.

The HeightInspect object succeeds or fails when the end conditions are met within the specified time. The HeightInspect object can apply end conditions related to force and position.

Each end condition is always applied.
When all the success conditions for each end condition are met: The HeightInspect object execution ends. The execution is determined as succeeded and proceed to the next force guide object.
When at least one of the failure conditions for each end condition is met: The HeightInspect object execution ends. The execution is determined as failed and abort the force guide sequence.

End condition
Success condition
End conditions related to force Within the specified time of Timeout, reach the force specified by ContactForceThresh in the axial direction specified by ContactOrient
End conditions related to position Satisfy the following within the specified time of Timeout.

When the height inspection method is set to be inspected by distance (Tool):

The moving distance from the force guide object start point in the axial direction specified by ContactOrient exceeds the range of DistExpected - DistExpectedTol to DistExpected + DistExpectedTol.

When the height inspection method is set to be inspected by position (Base, Local):

The position when the workpiece touches in the axial direction specified by ContactOrient in the specified coordinate system is within the range of PosExpected - PosExpectedTol to PosExpected + PosExpectedTol.

End condition
Failure condition
End conditions related to position Satisfy the following within the specified time of Timeout.

When the height inspection method is set to be inspected by distance (Tool):

The moving distance from the force guide object start point in the axial direction specified by ContactOrient exceeds DistExpected + DistCheckTol.

When the height inspection method is set to be inspected by position (Base, Local):

The position when the workpiece touches in the axial direction specified by ContactOrient in the specified coordinate system exceeds PosExpected + PosExpectedTol.

When the inspection method is set to be inspected by position (Base, Local) and the direction of operation is negative:

The position when the workpiece touches in the axial direction specified by ContactOrient in the specified coordinate system exceeds PosExpected- PosExpectedTol.

Property guidelines for HeightInspect object

Step 1. Set basic information
Set properties (Name, Description, StepID, AbortSeqOnFail) related to the basic information.

Properties
Description, setting guide
Name

This property sets names of force guide objects.

Set a particular name.

Description

This property sets descriptions about force guide objects.

Describe the operations. Set a character string.

StepID

StepID during the force guide object execution.

Set an ID.

StepID is an ID which is recorded in the log data. It helps you to understand which log data support a process.

It is applied when AutoStepID of the force guide sequence is False.

AbortSeqOnFail Set whether to abort or continue the force guide sequence when the force guide object fails.

True : Normal

End a force guide sequence.

False : Cases where the force guide sequence contains recovery operations in case of failure; cases where the sequence will be able to continue even in the event of a failure.

Step 2. Set contact direction and force control functions
Set properties (ContactOrient, ContactFirmnessF) related to the contact direction and the force control functions.

Properties
Description, setting guide
ContactOrient

Set a direction to contact.

The robot moves to the specified direction.

ContactFirmnessF Set a firmness of the force control functions.

When setting a large value:

The Force Control functions become stronger, but response to changes in force is slow.

When setting a small value:

The Force Control function will become weaker. Response to changes in force is fast; however, vibrations can easily occur.

You can check the settings of ContactOrient by a simulator. A coordinate system with grayed out except the specified direction is displayed.
However, the robot is displayed based on the current position. When you check the settings, make sure to move the robot to the position where executing the force guide object.
For details on how to check by using simulator, refer to the following manual.
"Epson RC+ 8.0 User's Guide: - Simulator - Description of Functions"

Step 3. Set the end conditions
Set properties (ContactForceThresh, Timeout) related to the end conditions.

Properties
Description, setting guide
ContactForceThresh

Set a threshold to determine a contact.

Set this to a tolerable value considering the workpiece in use.

When setting a large absolute value:

Movement speed until the robot makes contact will be fast.

When the value is too small:

Robot may not move.

Timeout

Set a time-out period of the HeightInspect object.

It fails if the specified time is passed before contacting.

Step 4. Set success conditions
Set properties (DistExpected, DistExpectedTol, PosExpected, PosExpectedTol) related to success conditions.

Properties
Description, setting guide
DistExpected

Set a reference distance to the expected point of contact from the start point of the motion.

This is the moving distance in the direction set by the HeightInspect object ContactOrient in the coordinate system set by the ForceOrient property for the HeightInspect sequence.

The inspection reference distance is distance 1 from the start point of the motion indicated by the red dot at the top of the diagram below, to the contact point represented by the red dot at the bottom.

image

If DistInspect is set as the InspectMethod for the HeightInspect sequence, it will be used as a success condition.

Teach the robot a start point of the motion that shortens the inspection reference distance as much as possible. As the force control function is slower than position control, longer inspection reference distances will result in longer cycle times.

DistExpectedTol

Set a tolerance of the reference distance to the expected point of contact from the start point of the motion.

The diagram below provides a visual representation of the DistExpectedTol property.

image

If "DistInspect" is set as the InspectMethod for the HeightInspect sequence, it will be used as a success condition.

PosExpected

Set an expected point of contact.

This is the position in the direction set by the HeightInspect object ContactOrient in the coordinate system set by the ForceOrient property for the HeightInspect sequence.

The inspection reference point is the point of contact depicted by the red dot at the top of the diagram below.

image

If "PosInspect" is set as the InspectMethod for the HeightInspect sequence, it will be used as a success condition.

PosExpectedTol

Set a tolerance for the expected point of contact.

The diagram below provides a visual representation of the PosExpectedTol property.

image

If "PosInspect" is set as the InspectMethod for the HeightInspect sequence, it will be used as a success condition.

Details on properties of HeightInspect object

  • Name Property
    This property sets a particular name that is assigned to force guide object.
    When creating the HeightInspect sequence, name is assigned automatically. Automatically assigned name is added a number after HeightInspect (e.g. HeightInspect01).
    You can change the name. Set up 16 characters at the maximum. Please use alphanumeric characters and underscores [_]. Note: The initial character cannot be a numeric character.
  • Description Property
    This property sets descriptions about force guide objects. You can set the character string up to 255 characters.
  • StepID Property
    This property sets StepID during the execution of the force guide objects.
    It is only used when AutoStepID is False.
    Value
    Minimum Value 0
    Maximum value 32767
    Default: Automatically set according to the numbers of the force guide sequence and the force guide object.
  • AbortSeqOnFail Property
    This property sets operations when force guide object fails.
    When True is specified: If the force guide object fails, the program ends the force guide sequence and proceeds to the next SPEL statement.
    When specifying False: If force guide object fails, the program proceeds to the next force guide object without ending the force guide sequence.
    Use this property when you want to continue the force guide sequence (e.g. the recovery processes are included in the force guide sequence when the force guide object fails.)
    Value
    Description
    True Abort the force guide sequence when the force guide object fails.
    False Start the next force guide sequence when the force guide object fails.
    Default: True
  • ContactOrient Property
    This property sets the direction of motion for height inspection operations in the coordinate system specified by the ForceOrient property for the force guide sequence. The robot moves to the specified direction, and when the robot contacts something, stops.
    Value
    Description
    +Fx Sets the direction of motion to the +Fx direction in the specified coordinate system.
    -Fx Sets the direction of motion to the -Fx direction in the specified coordinate system.
    +Fy Sets the direction of motion to the +Fy direction in the specified coordinate system.
    -Fy Sets the direction of motion to the -Fy direction in the specified coordinate system.
    +Fz Sets the direction of motion to the +Fz direction in the specified coordinate system.
    -Fz Sets the direction of motion to the -Fz direction in the specified coordinate system.
    Default: +Fz
  • ContactFirmnessF Property
    This property sets the firmness in relation to the force control function in the direction of motion specified by the ContactOrient property for the force guide object during the execution of the force guide object.
    The larger the ContactFirmnessF value, the stronger the force control function becomes in the direction of motion. This slows response to changes in force, but reduces vibration.
    The smaller the ContactFirmnessF value, the weaker the force control function becomes in the direction of motion. This speeds up response to changes in force, but increases vibration.
    Value
    Minimum Value 0.1
    Maximum value 10
    Default: 1.5
  • ContactForceThresh Property
    This property sets a threshold of force to determine the contact.
    If the threshold set by this property is exceeded during execution of HeightInspect object, the robot recognizes that the robot is contacted and stops the motion. Then, proceed to the next force guide object.

    • When ContactOrient is in positive direction:

      Value (unit: [N])
      Minimum Value -10
      Maximum value -0.1

      Default: -2

    • When ContactOrient is in negative direction:

      Value (unit: [N])
      Minimum Value 0.1
      Maximum value 10

      Default: 2

  • DistExpected Property
    This property sets the distance from the height inspection start point to the position to be contacted. Use this property when DistInspect is set for the InspectMethod property of the force guide sequence.
    Value (Unit: [mm])
    Minimum Value 0
    Maximum value 50
    Default: 10
  • DistExpectedTol Property
    Specify the range that is the success condition (when the operation is finished) of the distance moved from the operation start position.
    The success condition is the range of DistExpected - DistExpectedTol to DistExpected + DistExpectedTol
    Value
    Minimum Value 0.01
    Maximum value 10
    Default: 1
  • PosExpected Property
    This property sets the position to be contacted. Use when PosInspect is set for the InspectMethod property of the force guide sequence.
    Value (Unit: [mm])
    Minimum Value -2000
    Maximum value 2000
    Default: 100
  • PosExpectedTol Property
    This property sets the range that is the success condition of the contacted distance when the operation is finished.
    The success condition is the range of PosExpected - PosExpectedTol to PosExpected + PosExpectedTol
    Value
    Minimum Value 0.01
    Maximum value 10
    Default: 1
  • Timeout Property
    This property sets the time-out period of the force guide object.
    When the robot does not satisfy the conditions set by ContactForceThresh even the time specified by Timeout has passed, it determines as failure of the HeightInspect object.
    After the determination, end the force guide sequence according to AbortSeqOnFail or proceed to the next force guide object.
    Value (unit: [sec])
    Minimum Value 0.1
    Maximum value 60
    Default: 10

Details on results of HeightInspect object

  • EndStatus Result
    It is a result of the execution.
    It will be succeeded when satisfying "success conditions" described in
    HeightInspect Object
    Value
    Description
    Passed Force guide object is succeeded.
    Failed Force guide object is failed.
    NoExec Force guide object is not executed.
    Aborted Aborted during the execution of force guide object.
  • Time Result
    This is the time required for execution.
    Unit: [sec]
  • TimedOut Result
    Shows whether the time-out period set in the Timeout property was reached.
    Value
    Description
    True Reached the time-out period.
    False End before reaching to the time-out period.
  • EndForces Result
    It is force and torque when force guide object ends. Acquire values of Fx, Fy, Fz, Tx, Ty, and Tz.
    Unit: Fx, Fy, Fz [N] / Tx, Ty, Tz [N・mm]
  • EndPos Result
    Positions when the force guide object ends. Acquire values of X, Y, Z, U, V, and W.
    Unit: X, Y, Z [mm] / U, V, W [deg]
  • AvgForces Result
    Average values of force and torque during the force guide object execution. Acquire values of Fx, Fy, Fz, Tx, Ty, and Tz.
    Unit: Fx, Fy, Fz [N] / Tx, Ty, Tz [N・mm]
  • PeakForces Result
    Peak values of force and torque during the force guide object execution. The peak value is a value which absolute value is the largest. Acquire values of Fx, Fy, Fz, Tx, Ty, and Tz.
    Unit: Fx, Fy, Fz [N] / Tx, Ty, Tz [N・mm]
  • ForceCondOK Result
    Shows whether the end condtions related to force were satisfied.
    Value
    Description
    True Satisfy the end conditions related to force.
    False The end conditions related to force are not satisfied.
  • TriggeredForces Result
    It is the force and torque when satisfying the end conditions related to force. Acquire values of Fx, Fy, Fz, Tx, Ty, and Tz.
    Unit: Fx, Fy, Fz [N] / Tx, Ty, Tz [N・mm]
  • TriggeredPos Result
    Positions when satisfying the end conditions related to force. Acquire values of X, Y, Z, U, V, and W.
    Unit: X, Y, Z [mm] / U, V, W [deg]
  • PosCondOK Result
    Value
    Description
    True Satisfy the end conditions related to position.
    False The end conditions related to position are not satisfied.
  • PosLimited Result
    Shows whether the limit range related to position was exceeded.
    Value
    Description
    True Exceed the limit range related to position.
    False The limit range related to position is not exceeded.

← Adjustment Guidelines for the HeightInspect Sequence and Object Property Values →

© 2024 Seiko Epson Corp.