ikin (Manual Mode)

This section explains how to use ikin during Manual (Teach) operations. This function computes the inverse kinematics (IK) solution for a given target pose. It converts a desired Cartesian position and orientation [X, Y, Z, Rx, Ry, Rz] into the corresponding joint angles [J1 … J6], allowing users to verify or simulate reachable configurations before actual motion execution.

Typical usage

  • Calculate joint angles for a desired TCP pose without moving the robot.

  • Validate whether a target position is kinematically reachable.

  • Compare multiple IK solutions (solution spaces) for collision-free teaching.

  • Generate approach or backup poses numerically during calibration.

Note

  • This function does not move the robot; it only performs mathematical IK computation.

  • For direct motion, use movej or movel with the calculated result.

Example: Compute joint angles for a target pose

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

int main() {
    CDRFLEx drfl;

    // Preconditions:
    // - Connection established (open_connection)
    // - Manual (Teach) mode active

    // Step 1. Define a target pose (in BASE frame)
    float targetPose[NUM_TASK] = {400.0f, 0.0f, 300.0f, 180.0f, 0.0f, 180.0f};

    // Step 2. Select solution space (0: default / elbow-down)
    unsigned char solSpace = 0;

    // Step 3. Perform inverse kinematics calculation
    LPROBOT_POSE pJoints = drfl.ikin(targetPose, solSpace, COORDINATE_SYSTEM_BASE);

    // Step 4. Print the computed joint values
    if (pJoints) {
        printf("[IK Result] J1=%.3f  J2=%.3f  J3=%.3f  J4=%.3f  J5=%.3f  J6=%.3f\n",
               pJoints->_fX, pJoints->_fY, pJoints->_fZ,
               pJoints->_fRx, pJoints->_fRy, pJoints->_fRz);
    } else {
        printf("[IK Result] Target pose not reachable.\n");
    }

    return 0;
}

In this example, a target Cartesian pose is defined in the BASE frame, and ikin is used to compute the joint angles that achieve that pose. This allows the operator to test reachability or prepare motion commands offline without physically moving the robot arm.

Tips

  • Use for offline pose verification or alternative configuration testing.

  • If no solution is found, check for singularities or unreachable workspace limits.

  • Compare with fkin to confirm pose consistency between forward and inverse models.

  • Record multiple IK solutions (different iSolutionSpace) to select the optimal path for constrained environments.