DEVELOPMENT OF A PROTOTYPE THREE–FINGER TELEROBOTIC HAND WITH FORCE FEEDBACK FOR GRASPING MULTIFORM OBJECTS

Abstract

the demand for adaptability in dynamically changing conditions, and the desire for enhanced precision in remote operations. These factors necessitate the deployment of highly dexterous robotic hands for mechanical tasks, with humans in the loop for high-level planning and decision-making. Despite their potential in healthcare, manufacturing, space, disaster response, and agriculture, widespread adoption of telerobotic hands is limited by high costs, restricted motion, and control challenges. To address this, a prototype low-cost, 3D-printed, three-finger telerobotic hand was developed. The development process began with the conceptual design of the hand’s mechanical structure, followed by design theories to determine finger length, grasping capability, load-carrying capacity, and power requirements. A 3D CAD model was created using SolidWorks and fabricated with a 3D printer, while circuit layout of the components was developed in Fritzing. The assembled components were integrated with electronic modules and programmed in the Arduino IDE to receive servomotors control signals from a joystick-based wireless controller and transmit force-sensitive resistor (FSR) force signals to the robotic hand via Bluetooth communication. The wireless controller itself was designed for ergonomic use. It features adjustable joysticks positions for different hand sizes, signal mapping strategies, and micro-vibration motors for haptic feedback. The platform for its hardware assembly was modeled in SolidWorks and fabricated via 3D printing. The circuit layout of the components was developed in Fritzing. The assembled components were integrated with electronic modules and programmed in the Arduino IDE to transmit servomotors control signals to the robot hand and receive micro-vibration motors control signals generated from FSRs via Bluetooth communication. The hand supports four distinct ranges of motion, namely flexion, extension, abduction, and adduction, and includes fingertip FSRs to measure the force exerted on objects. Experimental results show the telerobotic hand effectively replicated human thumb, index, and middle finger movements as controlled by the joysticks. The system achieved 96.2% motion accuracy resulting from flexion (99.1%), abduction (95%), and adduction (94.5%), with minimal deviation. It attained an 87% grasping success rate with an average grasp time of 2.17 seconds. A positive correlation between measured force and vibration intensity validated the haptic feedback's effectiveness. User feedback indicated an 84% average satisfaction across responsiveness, ease of use, comfort, haptic feedback, fatigue, and task completion. The prototype successfully demonstrated its ability to replicate human finger motions and provide intuitive control with meaningful force feedback.