set_user_cart_coord (3-point, Manual Mode)

This section explains how to use set_user_cart_coord2 during Manual (Teach) operations. It defines a user coordinate system using the 3-point method, where the user specifies three poses: origin, X-direction, and Y-plane points.

This method defines both position and orientation of the work frame based on real surface data.

Typical usage

• Create a user frame aligned to a workpiece surface.

• Define a frame tilted or rotated relative to BASE.

• Use for welding jigs, assembly tables, or camera calibration.

Note

• Inputs: fTargetPos[3][NUM_TASK] (O, Xp, Yp) and fTargetOrg[3].

• Orientation is automatically computed and normalized.

• Must be done carefully to avoid collinear point selection.

• Reference (eTargetRef) usually set to COORDINATE_SYSTEM_BASE.

Example: Define a Workpiece Frame with 3 Physical Points

#include "DRFLEx.h"
#include <thread>
using namespace DRAFramework;

int main() {
    CDRFLEx drfl;

    float points[3][NUM_TASK];
    float origin[3];

    printf("Teaching USER frame using 3 physical points...\n");

    // Step 1. Record origin (corner of workpiece)
    auto pO = drfl.get_current_posx(COORDINATE_SYSTEM_BASE);
    memcpy(points[0], pO, sizeof(float)*NUM_TASK);
    origin[0] = pO->_fX; origin[1] = pO->_fY; origin[2] = pO->_fZ;

    // Step 2. Move +X and record
    drfl.jog(JOG_AXIS_TASK_X, MOVE_REFERENCE_BASE, 5.0f);
    std::this_thread::sleep_for(std::chrono::milliseconds(600));
    drfl.stop(STOP_TYPE_SLOW);
    auto pX = drfl.get_current_posx(COORDINATE_SYSTEM_BASE);
    memcpy(points[1], pX, sizeof(float)*NUM_TASK);

    // Step 3. Move +Y and record
    drfl.jog(JOG_AXIS_TASK_Y, MOVE_REFERENCE_BASE, 5.0f);
    std::this_thread::sleep_for(std::chrono::milliseconds(600));
    drfl.stop(STOP_TYPE_SLOW);
    auto pY = drfl.get_current_posx(COORDINATE_SYSTEM_BASE);
    memcpy(points[2], pY, sizeof(float)*NUM_TASK);

    // Step 4. Register user frame based on 3-point calibration
    int user_id = drfl.set_user_cart_coord(points, origin, COORDINATE_SYSTEM_BASE);

    printf("USER%d frame successfully defined using 3-point method.\n", user_id);

    return 0;
}

Tips

• Ensure the three points are not collinear and represent the actual plane.

• Best for slanted surfaces or tilted fixtures.

• Combine with calc_coord for pre-verification.

• Use coord_transform to validate alignment.