# Pneumatic–Cable-Hybrid-Driven Multi-Mechanism End Effector and Cross-Surface Validation

## TL;DR

This paper introduces a hybrid-driven end effector for wall-climbing robots that adapts to both rough and smooth surfaces, enabling stable adhesion and movement.

## Contribution

A novel pneumatic–cable-hybrid-driven end effector with multi-mechanism adhesion for cross-surface adaptability in wall-climbing robots.

## Key findings

- The end effector combines claw-based interlocking and vacuum suction for reliable adhesion on rough and smooth surfaces.
- A cable-driven adjustment mechanism improves stability and load capacity under varying surface conditions.
- The system enables seamless switching between adhesion modes, supporting continuous mobility on diverse surfaces.

## Abstract

Wall-climbing robots are increasingly required for applications in aerospace, high-altitude operations, and complex environmental monitoring, where they must maintain reliable adhesion and continuous mobility across surfaces with rapidly changing material properties and roughness. Achieving these demands requires lightweight systems with end effectors that integrate multi-surface adaptability and load-carrying capacity. Current single adhesion mechanisms are typically effective only under specific wall conditions, making it challenging to achieve stable, continuous adhesion and detachment on surfaces with significantly different roughness. To address this limitation, we propose a flexible, multi-mechanism coupled end effector driven by a pneumatic–cable hybrid system, integrating two complementary adhesion mechanisms—claw-based interlocking and vacuum suction—into a unified flexible structure. First, we develop the overall structural framework of the end effector and conduct finite element simulations to analyze key structural parameters of the telescopic cavity. We then establish a contact force model between the claw and vertical rough surfaces to clarify the interlocking adhesion mechanism and determine critical geometric parameters. Based on these analyses, a cable-driven adjustment mechanism is introduced to enable dynamic self-adaptation and assist with load-bearing during adhesion, enhancing the stability and load-carrying capacity under varying wall conditions. On rough surfaces, the end effector achieves reliable adhesion through claw interlocking, while on smooth surfaces, it maintains stable attachment through vacuum suction. Furthermore, it supports seamless switching between adhesion modes on different surfaces. When integrated into a wall-climbing robot, the system enables stable adhesion and detachment on both rough and smooth surfaces, providing a feasible solution for the lightweight, integrated design of end effectors for multi-surface adaptive wall-climbing robots.