Multi-Modal Sensor for Fingertips of Anthropomorphic Grippers

The trend of robotic manipulation in complex and unstructured environments necessitates the integration of various sensory modalities to enable accurate and adaptive grasping and control. This paper presents the design, development, and integration of a multi-modal sensor for robotic gripper, incorporating tactile sensing based on optoelectronic technology, Time of Flight (ToF) for pre-touch sensing, and Inertial Measurement Unit (IMU). Tactile sensing is fundamental for perceiving fine-grained surface textures, detecting pressure, and enabling precise object manipulation. Time-of-Flight pre-touch sensors offer proximity information with ultra-low latency, by enhancing environment interaction or anticipatory human-robot responses. IMUs provide critical motion and orientation data to track gestures and postures, as well as temperature information about grasped objects. The developed remarkably compact sensor, measuring only 12.5 × 20 mm, making it suitable for integration on the fingertip of any robotic gripper, and sensor system aims to enhance the gripper’s abilities by providing real-time feedback about object properties, pose estimation and dynamic interactions during grasping and manipulation tasks. The novel multi-modal sensor has very smaller size equivalent to human fingertip and more robust design that yields the higher sensitivity, higher flexibility and less noise. Extensive tests on its measurement capabilities evaluated sampling frequency, noise, and precision. The sensor has been successfully integrated into a commercial three-fingered gripper, demonstrating its practical application in robotic manipulation tasks.