Abstract:

For improving the comprehensive driving performance in the gastrointestinal (GI) tract, a new type of petal-shaped capsule robot is proposed. The convergent wedge-like gap is formed between each surface of the four eccentric tiles and the inner pipe wall, which changes the liquid flow path around each of the four convergent wedge-like gaps and generates multiple wedge effects. Based on Couette flow theory and Newton inner friction law, a fluid dynamics model of the petal-shaped capsule robot is derived. According to the analytical solution of swimming speed, hydrodynamic pressure and fluid resistance torsion moment, the comprehensive performance of the petal-shaped capsule robot are investigated. Theoretical and experimental results show that both fluid dynamic pressure and swimming speed of the petal-shaped capsule robot are improved greatly, and fluid resistance torsion moment is reduced significantly. The petal-shaped capsule robot possesses a better comprehensive performance, achieving the non-contact drive and complete suspension in the middle of the pipe, shorter diagnosis time, more weaken fluid resistance torsion moment and safer drive in the GI tract, the petal-shaped capsule robot has a promising application prospect in the GI diagnosis.

Key words: comprehensive performance, fluid resistance torsion moment, multiple wedge effects, petal-shaped capsule robot