YesAX V3.1.2 - Software User Manual - 第261页

Calibration and Verification 25 -1 25 - Calibration and V erif ication The software provides a comprehensive set of guided calibration procedures. Each procedure is prompted by a dialog message that gives the instruction…

Calibration and Verification 25-1

25 - Calibration and Verification

The software provides a comprehensive set of guided calibration procedures. Each procedure is

prompted by a dialog message that gives the instructions for the adjustment and lists the current

and the target values.

All the calibration procedures are launched from the Calibrate menu in the Builder mode.

The specialized calibration board (P/N 10876) is required for all calibrations and verifications.

The board must be properly aligned before any calibration begins.

25.1 Align Calibration Board

The Align Calibration Board is the procedure that guides the user through aligning the board in

the system. Upon starting the procedure the software opens the conveyor to the width of the

calibration board (approximately 559 mm wide). You may need to do some minor adjustments (1

or 2 mm) to the conveyor width for the calibration board to fit in. After the conveyor is opened to

the correct width, place the calibration board on the conveyor from the left opening and manually

push the board towards the center of the machine. Open the front door of the machine, reach in

with your hand and pull the calibration board further to the right so that it is over the hard stops.

The right edge of the calibration board should align approximately with the right limit sensor of

the X axis.

25.2 Calibrate XY Skew

This calibration adjusts the perpendicularity of the XY stage. The calibration involves removing

the top and side cover and the use of a special adjustment jig. This is a onetime adjustment. The

procedure is performed in the factory as part of the standard calibration procedure.

25.3 Align Conveyor Rail

This Align Conveyor Rail feature aligns the conveyor rail with the X axis. The software moves

between two points along the X axis, one on the left and the other on the right.

25-2 Calibration and Verification

25.4 Calibrate Stage Linear Comp

The YesAX software compensates for mechanical imperfections of the XY camera transport

mechanism. The software employs three scaling factors for compensation: X, Y, and Skew. The

X factor compensates for any linear error on the X axis that may be caused by inaccuracies of the

X lead screw. The Y factor compensates for linear error on the Y axis and the skew factor

compensates for imperfect XY orthogonality. The Calibrate Stage Linear Comp feature

calibrates these 3 compensation factors.

25.5 Error Map XY Stage

To compensate for non-linear distortion of the XY stage, the Error Map XY Stage feature

extends the error compensation features to include error mapping. The linear error compensation

mentioned earlier uses 3 scale factors to compensate for linear errors commonly found on an XY

stage. Error mapping compensates for all remaining errors by mapping it. Typically, error

mapping, when performed correctly, can increase stage accuracy by a factor of three.

Error mapping employs a grid (for example 27 x 24) of error correction factors. It maps the

distortion of the positioning system. The error correction of any given point is determined by

using a linear formula with the data from the 3 closest correction factors.

25.6 Calibrate Camera Angle

This Calibrate Camera Angle feature calibrates the angle of the top camera to have it aligned

with the X axis. During the procedure, the stage moves left and right to have the target cross on

the calibration board appear on the left and then right side of the field of view. If the camera

angle is correct, the video cross hair should align with the target cross in both positions. To

adjust camera angle, loosen the three small mounting screws (5/64 button head) that hold the

camera PCB to the mounting bar and rotate the camera PCB.

25.7 Calibrate Camera Pixel Size

This Calibrate Camera Pixel Size feature calibrates the pixel size of the top camera. The XY

stage encoder is used as a ruler. The pixel size is determined using the following formula:

Stage movement delta in um

Pixel Size in um = -----------------------------------

Pixel delta in count

To adjust the camera pixel size, raise or lower the camera by putting washers in the camera

mount. Raising the camera increases the pixel size.