What are force-torque sensors and how do they benefit manipulation tasks?

• A. Sensors measure ambient light to adjust camera exposure.
• B. Sensors measure forces and moments at the end effector, enabling tactile feedback, compliant control, and contact-aware manipulation.
• C. Sensors measure temperature at gripper.
• D. Sensors measure battery state.

Answer: (B)

The key idea is that force-torque sensors measure the forces and moments acting at the robot’s end effector, giving the system direct tactile feedback during manipulation. By capturing six components—three forces and three torques—the robot can sense how it is contacting and interacting with objects, surfaces, or other agents.

This tactile information enables compliant or impedance/admittance control, where the robot adjusts its stiffness and motion in response to external forces rather than forcing a rigid path. That makes manipulation safer and more reliable, especially when handling delicate parts, assembling with tight tolerances, or interacting with humans and uncertain environments. The robot can detect when contact occurs, estimate contact conditions, and adapt grip strength, trajectory, or insertion motions accordingly, improving accuracy and reducing the risk of damage.

Force-torque sensing is typically placed at the wrist or inside the gripper, continuously providing data that the control system uses to refine motion in real time. The other options describe sensors that measure ambient light, temperature, or battery state, which do not provide the tactile, contact-aware information needed for robust manipulation.