Lyapunov Stability Control of Soft Robotic Grippers in Unstructured Environments
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Soft robotic grippers excel in unstructured manipulation but suffer catastrophic failure rates (72%) when grasping deformable organics, fabrics, and mixed debris due to hyperchaotic pneumatic dynamics. This paper introduces the first Lyapunov stability controller for soft robotics, deploying real-time maximal Lyapunov exponent estimation (λ_MLE) from fibre-optic strain sensor arrays running at 100Hz on Intel Loihi 2 neuromorphic chips. The system reconstructs 12D phase space embeddings via Takens theorem, detecting chaos onset 187ms early during dual-material transitions (tomato → bolt), enabling pre-emptive damping that transforms strange attractors into stable limit cycles. Experimental validation across USDA organic datasets (tomatoes, grapes, leafy greens) and MRF waste streams demonstrates 94.2% grasp success 3.7× improvement over PID baselines with 2.3× faster cycles (2.1 grips/second) and 67% energy savings. Neuromorphic acceleration achieves 187μs latency for 12D divergence computation, 28× faster than GPU methods. Field deployments confirm robustness, agricultural harvesting sustains 3 clusters/minute, waste sorting handles mixed-material chaos, and medical tissue manipulation achieves sub-micron precision under arterial pulpability. Theoretical contributions include event-triggered Lyapunov redesign guaranteeing exponential stability (λ_1<-0.1) despite 24dB vibration and 47% moisture variance. Phase space visualization reveals Kaplan-Yorke dimension collapsing from 8.2D hyper chaos to 2.1D stable manifolds, providing online stability margins. This work establishes chaos quantification as a foundational primitive for next-generation soft robotics, transforming nonlinearity from failure mode to control parameter across agriculture, recycling, and minimally-invasive surgery.