CENTER FINDER MENU SCREENS


CENTER FINDER MENU SCREENS

1. CENTER FINDER MENU SCREEN

Center Finder is a motion option that allows you to find the center of a two-dimensional symmetric shape such as a circle, hexagon, or triangle. The found center can be used as a reference point. You might use it for position recording incremental positions from the center of a chuck, for example.

Table 1.  Center Finder Menu Items

ITEM

DESCRIPTION

Position Register

This item allows you to select which position register you want to use. When you select a different position register, the x, y, z, w, p, and r positions will display the content of the selected position register.

Motion Frame

This item allows you to select which motion frame you want to use for the contact search motions. There are six selections:

  • World: Robot world frame

  • Tool: Robot current tool frame

  • user: Current $MNUFRAME

  • World + Z: Robot world frame + Z direction offset *

  • Tool + Z: Robot $MNUTOOL frame + Z direction offset *

  • User + Z: Current $MNUFRAME + Z direction offset *

Plane Axis

This item allows you to select which axis will function as the Plane Axis. The Plane Axis is the axis normal to the plan that contains the shape. There are six selections:

  • X Axis

  • Y Axis

  • Z Axis

  • —X Axis

  • —Y Axis

  • —Z Axis

Search Type

This item allows you to set the type of search that Center

Finder will perform. There are seven selections:

  • Collet Chuck: chuck without fingers

  • Three Finger Chuck: chuck with three fingers

  • Four Finger Chuck: chuck with four fingers

  • Shape: Any symmetric shape, such as circle, hexagon, oval, or rectangle

  • X: Center of two points in plane X axis **

  • Y: Center of two points in plane Y axis **

  • Z: Center of two points in plane Z axis **

Motion Setup

This item displays whether Motion Setup is complete or incomplete for Center Finder. You must set up motion for your environment the first time you use Center Finder.

Orientation Setup

This item displays whether Orientation Setup is complete or incomplete for Center Finder. Orientation Setup is optional. It allows you to adjust the robot so the tool is perpendicular to the plane that contains the geometry.


2. CENTER FINDER MOTION SETUP SCREEN

Table 2.  Center Finder Motion SETUP Menu

ITEM

DESCRIPTION

Points on Plane

This item specifies the number of searches for the shape. For x axis, y axis, and z axis search types, this setting is ignored.

Motion Speed

This item specifies the normal motion speed when the robot is looking for the contact.

Search Speed

This item specifies the contact searching speed when the robot is moving back from a contact position to a search position.

Search Distance

This item specifies the maximum amount of distance the contact search motion will travel. If the robot does not detect a contact within the search distance, an error will be posted.

Learn Distance

Units: mm

Range: 0.5 – 10.0

Default: 5.0

For“TOS All Axes” method only, there is a short motion before each search to identify dynamic torque values. Learn Distance is the distance in millimeters of this short motion, the direction is determined at the time of the motion.

Learn Speed

Units: mm/sec

Range: 1.0 – 75.0

Default: 10.0

For“TOS All Axes” method only, this is the speed of the learning motion before each search.

Convergence Error

This item specifies the iteration convergence criteria. If the current iteration is within the specified error, the center position is found.

Do Z Check

This item allows you to set the Do Z Check flag. If the flag is set to TRUE, you can run Z direction for the chuck. If the flag is set to FALSE, you cannot execute Z_MOVE.

Orientation Angle

This item specifies the maximum allowable orientation change for setting up the orientation of the tool to be perpendicular to the chuck surface.

Sensitivity Tolerance

This item allows you to set the sensitivity tolerance for the Torque Observer Sensor (TOS). The lower the number is, the more sensitive the TOS will be.

Warning

Be careful when changing this number. Changing the sensitivity tolerance might cause a false detection. This could injure personnel or damage equipment.

Torque Threshold

This item allows you to set the percentage of torque the robot will put out before it detects a contact.

Sensor Type

Values: TOS Wrist , I/O, TOS & I/O, or TOS All Axes

Default: TOS All Axes

This item indicates the kind of sensor used with TCP calibration. The three modes are:

  • TOS Wrist (Torque Observer Sensor on Wrist) - The contact torque will be monitored, and only the observed torque will be used to determine the contact position. When TOS Wrist is selected, no I/O connection is required for contact detection.

  • I/O - The specific I/O will be monitored and only the state of this input will be used to determine the contact position. Center Finder uses either DI or RDI.

  • TOS & I/O - Both torque and I/O will be monitored, and the first one to be detected will be used to determine the contact position. If the Sensor Type is set to TOS, you do not need to set up I/O.

  • TOS All Axes (Torque Observer Sensor, All Axes) - The contact torque will be monitored on all robot axes, and only the observed torque will be used to determine the contact position. This is the default value. When TOS All Axes is sected, no I/O connection is required for contact detection.

Detection Port Type

Values: RDI, DI, WDI, WSI

Default: DI

This item allows you to select RDI, DI, WDI, or WSI (wire stick-out input port) for the contact detection port.

Detection Port Number

Default: 0

This item allows you to select the I/O port number for the contact detection port.

Sensor Enable Port Type

Values: RDO, DOUT, WDO, WSO

Default: DOUT

This item allows you to set the sensor enable port type to RDO, DOUT, WDO, or WSO This is optional. If your I/O detection port needs to be enable before it can do contact detection, you have to set up this port.

Sensor Enable Port Number

Default: 0

This item allows you to set the digital output port number for the circuit enable port.


3. TROUBLESHOOTING CENTER FINDER

Table 3.  Troubleshooting Information

ERROR SOLUTION

Robot does not make contact with the part

  • Increase the search distance in the Center Finder Motion Setup menu if the robot is moving along a correct search direction.

  • Re-teach the search start position so it is closer to the part.

Robot does not make solid contact with the part and returns to the search start position prematurely.

Display the Center Finder system setup sub-menu and change the Sensitivity Tolerance to a larger number.

Excessive vibration when robot is returning from the contact position back to the search start positions.

Display the Center Finder system setup sub-menu and reduce the motion speed.

Center Finder does not have enough information to determine the center and reports a "Cannot Converge" error.

Increase the number of points on the shape.