Design and Analysis of a Multimode Sarrus-Derived Mechanism for Enhancing Robot Adaptability

Robot adaptability in complex terrains remains a crucial challenge. To address this, we introduce a novel class of spatial 8R mechanisms derived from the Sarrus linkage and further develop a multimode Sarrus-derived mechanism (MSDM) to enhance robotic adaptability. The mechanism exhibits six distinct motion modes: two with multiple configurations, two with multiple branches, and two with both. Notably, local degrees-of-freedom (DOFs) enable postoverturning self-recovery capability, while continuous parallelogram motion of limbs improves terrain adaptability. First, the motion modes of the MSDM are identified, and their kinematic properties are characterized. Second, a mechanical design is carried out, leading to two trunk-oriented application schemes. Finally, a prototype is fabricated and integrated into a wheeled robot, demonstrating the mechanism's feasibility. This work offers a novel paradigm for enhancing robot adaptability via reconfigurable mechanisms.