Miniature Peristaltic Pump-Driven Compliant Underactuated Robotic Gripper with Sensorless Force Control
Description
Traditional pneumatic underactuated grippers mostly rely on external air compressors for air supply, which suffer from bulky size, poor portability, and low integration, thus limiting their application on mobile and lightweight robotic platforms. To explore potential solutions to these issues, this paper proposes a Peristaltic pump-driven compliant Underactuated force-controlled robotic Grasping (PUG) system. Specifically, first a force-controlled underactuated gripper driven by a miniature peristaltic pump is designed and fabricated, without requiring an external air compressor as the power source. Second, three connection configurations between the double-acting cylinder and the peristaltic pump are designed, and their actuation characteristics are comparatively evaluated through experiments, from which a preferable pneumatic scheme is selected. Finally, a control strategy combining a single-stage pressure-rise model with feedforward–proportional-integral (PI) control is proposed, providing a feasible solution for force control of the underactuated gripper without requiring fingertip-mounted force sensors. Experimental results show that the system achieves a force control nonlinearity error of 4.3%, an average force tracking error of 0.15 N, and an average grasping range perception error of 2.69 mm. Adaptive grasping experiments on regular, irregular, fragile, and miniature objects preliminarily validate the system's versatility and non-destructive grasping capability. Compared with conventional air-compressor-driven schemes, the proposed system offers certain advantages in terms of mass and volume, and may serve as a technical reference for the development of lightweight and highly integrated grippers.