ikin_norm

This function performs inverse kinematics with normalization applied to the resulting joint angles. It calculates the joint position corresponding to the given TCP pose (fSourcePos) and adjusts the output to remain within normalized joint limits, ensuring consistent solutions across different configurations.

Definition
DRFLEx.h within class CDRFLEx, public section (line 669)

LPINVERSE_KINEMATIC_RESPONSE ikin_norm(
    float fSourcePos[NUM_TASK],
    unsigned char iSolutionSpace,
    COORDINATE_SYSTEM eTargetRef,
    unsigned char iRefPosOpt
) {
    return _ikin_norm(_rbtCtrl, fSourcePos, iSolutionSpace, eTargetRef, iRefPosOpt);
};

Parameter

Parameter Name	Data Type	Default Value	Description
fSourcePos	float[6]		Target TCP position in task space (x, y, z, Rx, Ry, Rz).
iSolutionSpace	unsigned char		Solution space index (0–7) selecting one of eight valid IK configurations.
eTargetRef	COORDINATE_SYSTEM	COORDINATE_SYSTEM_BASE	Reference coordinate system for the TCP.
iRefPosOpt	unsigned char		Reference pose option used by the normalized IK solver (e.g., to constrain solutions within a specified configuration neighborhood).

Return

Value	Description
LPINVERSE_KINEMATIC_RESPONSE	Normalized inverse-kinematics response structure containing the calculated and normalized joint positions. Refer to the definition of the structure in the Structures section.

Example

float tcp_pose[6] = { 500.0f, 400.0f, 300.0f, 180.0f, 0.0f, 90.0f };
LPINVERSE_KINEMATIC_RESPONSE res = drfl.ikin_norm(tcp_pose, 1, COORDINATE_SYSTEM_BASE, 0);

float q_normalized[6] = {0};
for (int i = 0; i < 6; ++i)
    q_normalized[i] = res->_fJoint[i];   // normalized joint angles

drfl.movej(q_normalized, 50, 20);

In this example, the target TCP pose tcp_pose is solved for solution space 1 in the BASE frame. The resulting joint angles are normalized (e.g., within ±π range) to prevent discontinuities. This is useful when performing continuous path motions or calibration that require consistent joint states.