A novel rigid-soft gripper for safe and reliable object handling

This research paper proposes a novel robotic gripper that combines rigid and soft components. The challenge of developing robotic grippers that can safely handle a wide variety of objects and remain stable, especially under harsh vibration, is addressed. The gripper uses a main rigid structure for maintaining the stiffness of the robot hand and soft pads under air pressurization for handling the softly and flexibly the objects. The proposed design capitalizes on the advantages of both rigid and soft grippers, by using rigid clamps to achieve robust gripping movements. Simultaneously, exploiting the soft pads' deformation to generate gripping force, this integration not only has high reliability but also guarantees safety in gripping objects. The novel concept, design, and fabrication of the gripper are introduced. Then, the gripper's ability was validated through mathematical modeling, analysis, and experiments. In particular, the geometrical kinematics of the rigid mechanism and deformation of the soft element is mathematical modeled and numerical simulation. Subsequently, the effective gripping size and contact force are analyzed. Experiments are conducted to verify the accuracy of the mathematical model and simulations, as well as to assess the capabilities of the proposed gripper design. The gripping experiment validates that the gripper can securely grasp a diverse range of objects while ensuring stability during subsequent movements, even under intense high-frequency vibration conditions. This gripper design can be applied for handling a wide range of objects with varying sizes, masses, fragility, and placement positions, specially when the gripping process necessitates both safe interaction and high reliability.