Calc Oblong Hole Center Poses and Axis Lengths

Function

This Procedure calculates the longitudinal axis and radii of the oblong hole and outputs the pose of the oblong hole’s center in the camera reference frame.

Usage Scenario

This Procedure is usually used in measurement scenarios for large workpieces. Usually, the Extract Planar Point Clouds Procedure is used before this Procedure to obtain the planar point cloud, and the Transform Poses to Custom Frame Procedure follows this Procedure to obtain the pose in the base reference frame.

Input and Output

../../../../_images/calc_oblong_hole_center_poses_and_diameter.png

Parameter Tuning

Detect and Measure Oblong Hole

ROI:
Parameter description: This parameter is used to set an ROI and read the center pose and size information of the oblong hole.
Tuning recommendation: Please select an ROI in the Measurement Mode, and set an accurate ROI.

Hint

When selecting an ROI, please make the selection frame as close to the oblong hole as possible. An inaccurate ROI will affect the accuracy of the measured oblong hole.

  • Center X/Y: The coordinates of the oblong hole’s center.

  • Width: The width of the oblong hole (l in the figure below).

  • Height: The height of the oblong hole (b in the figure below).

  • Angle: Set the rotation angle of the ROI selection frame. When the oblong hole is in a horizontal or vertical direction, you do not need to set this parameter.

../../../../_images/oblong_hole.png

Extract 3D Points in Cylinder

Hint

When this Procedure is executed, the point cloud will be converted from the camera reference frame to the point’s reference frame. The following parameters are used to set the range of the Z coordinates in the point’s reference frame.

Min Z Value:
Parameter description: This parameter specifies the minimum value (unit: m) of the Z coordinate in the point’s reference frame. The smaller the value, more points will be extracted.
Default value: -0.0005 m
Max Z Value:
Parameter description: This parameter specifies the maximum value (unit: m) of the Z coordinate in the point’s reference frame. The larger the value, more points will be extracted.
Default value: 0.0005 m

Tuning Example

Angle

This parameter is used to set the rotation angle of the ROI selection frame. In the actual large workpiece measurement scenarios, the oblong holes may be in varied directions, and the ROI selection frame can only be in the horizontal or vertical direction. You will need to set the Angle if the oblong hole is not in the horizontal or vertical direction to make the ROI selection frame as close to the oblong hole as possible.

The figure below shows the effect before and after the Angle is adjusted. The orange frame represents the ROI selection frame.

../../../../_images/adjust_angle.png