task_compliance_ctrl

This function starts task-space compliance control (Cartesian stiffness control) in the specified reference coordinate system.

To end compliance control, use release_compliance_ctrl.

Definition
DRFLEx.h within class CDRFLEx, public section (line 947)

bool task_compliance_ctrl(float fTargetStiffness[NUM_TASK],
                          COORDINATE_SYSTEM eForceReference = COORDINATE_SYSTEM_TOOL,
                          float fTargetTime = 0.f) {
    return _task_compliance_ctrl(_rbtCtrl, fTargetStiffness, eForceReference, fTargetTime);
};

Parameter

Parameter Name	Data Type	Default Value	Description
fTargetStiffness	float[6]	[3000, 3000, 3000, 200, 200, 200]	Stiffness for XYZ (translation) and Rx/Ry/Rz (rotation) Larger: stiffer (less compliant) Smaller values: softer (more compliant) Units: N/m (translation) and N·m/rad (rotation)
eForceReference	COORDINATE_SYSTEM	COORDINATE_SYSTEM_TOOL	Reference coordinate frame for stiffness control (e.g., TOOL, BASE, WORLD).
fTargetTime	float	0	Transition duration [sec] for stiffness change (range 0–1). Linear interpolation is used during the specified time.

Return

Value	Description
0	Failed
1	Success

Example A — Manual (Teach) Hand-Guiding

#include "DRFLEx.h"
using namespace DRAFramework;

int main() {
    CDRFLEx drfl;

    // Preconditions:
    // - Connection established
    // - Manual (Teach) mode active
    // - Servo power ON

    // 1) Move to a safe position before enabling compliance
    float q0[6] = { 0.0f, 0.0f, 90.0f, 0.0f, 90.0f, 0.0f };
    drfl.movej(q0, 60, 30);
    drfl.mwait();

    // 2) Define stiffness for each axis (lower = more compliant)
    float stiffness[6] = { 2500.f, 2500.f, 2500.f, 150.f, 150.f, 150.f };

    // 3) Enable compliance control in TOOL frame
    if (!drfl.task_compliance_ctrl(stiffness, COORDINATE_SYSTEM_TOOL, 0.1f)) {
        printf("Failed to start compliance control.\n");
        return -1;
    }

    printf("Compliance active. The arm can now be hand-guided safely.\n");

    // 4) Release compliance after teaching
    drfl.release_compliance_ctrl();
    printf("Compliance control released.\n");
    return 0;
}

Example B — Auto Mode (Insertion or Surface Contact Task)

// 1) Move to approach position
float p_app[NUM_TASK] = {550.f, 200.f, 150.f, 180.f, 0.f, 0.f};
drfl.movel(p_app, (float[2]){150.f, 30.f}, (float[2]){400.f, 150.f});
drfl.mwait();

// 2) Enable compliance (soft in Z and rotation)
float k_soft[NUM_TASK] = {2500.f, 2500.f, 1200.f, 100.f, 100.f, 100.f};
if (!drfl.task_compliance_ctrl(k_soft, COORDINATE_SYSTEM_TOOL, 0.2f)) {
    printf("Failed to enable compliance.\n");
}

// 3) Execute insertion motion under compliance
float p_down[NUM_TASK] = {550.f, 200.f, 90.f, 180.f, 0.f, 0.f};
drfl.movel(p_down, (float[2]){40.f, 15.f}, (float[2]){150.f, 60.f});
drfl.mwait();

// 4) Disable compliance after insertion
drfl.release_compliance_ctrl();
drfl.mwait();

// 5) Continue with precision motion
float p_final[NUM_TASK] = {550.f, 200.f, 85.f, 180.f, 0.f, 0.f};
drfl.movel(p_final, (float[2]){60.f, 20.f}, (float[2]){300.f, 120.f});
drfl.mwait();

Notes & Best Practices

• Activate compliance only during necessary operations. Disable it before executing fast or high-precision movements using release_compliance_ctrl.

• Use mwait() to ensure motion completion before switching between position and compliance control.

• Recommended stiffness values: XYZ 1500–2500, rotations 100–200.

• Use TOOL coordinate system for hand-guiding or alignment tasks.

• Use BASE coordinate system when compliance direction should follow the workspace axes.