Stability analysis and control of adhesive forces of bio-inspired spines
In this paper, a mechanical model of a compliant spiny toe inspired by the features of Serica orientalis Motschulsky's tarsal system is proposed. The contact forces of the compliant spine are obtained by considering the contact asperities as random curves, and the stability of the spine adhesion system is analyzed. A single spiny toe is fabricated via fast prototyping. The adhesive forces and displacements of the spine mechanism are measured with a homebuilt apparatus using displacement-control method under different compressive deformations. The testing results verify the theoretical model analysis. A force control system of the single compliant spine mechanism structure is also prosed. The system consists of four elastic spring damping subsystems in order to control the interferences and achieve stability in attachment state. The state-feedback control strategy is applied to optimize the control parameters for the original system. The simulation results show that the steady state of the spine system can be improved with the optimized feedback algorithm.