乌贼游动机理及其在仿生水下机器人上的应用

Swimming Mechanism of Squid/Cuttlefish and Its Application to Biomimetic Underwater Robots

针对大多数机器鱼未采用弹性机制来提高能量利用效率和耐压能力低等的不足,对拥有高超游动能力,具有耐压结构的乌贼进行研究。分析乌贼喷射和鳍波动推进的游动机理,给出喷射推力、喷射和整周期流体推进效率方程。乌贼复合游动方式的优点是高速性和低速性均很好,能瞬时改变游动方向,噪声低,以及即使喷射速度低于周围流体速度,也能产生推力。为深入说明乌贼游动机理,研究乌贼外套膜和鳍这两套运动系统的肌肉性静水骨骼结构及其动作原理。肌肉性骨骼不但具有支撑躯体,进行动作和输出力的作用,还具有良好的耐压能力。大多数乌贼体内没有充气组织,外套膜腔内外静压平衡,进一步提高了它们的耐压能力。乌贼动作时,弹性机制能够减少能量消耗,提高能量利用效率。若能将乌贼的游动方式、肌肉组织结构和弹性机制等特点应用到仿生水下机器人上,将使其更加高效、灵活和耐压。

According to the shortcomings of most robot fish, such as not incorporating elastic mechanism to improve energy efficiency and poor pressure resistance capability, squid/cuttlefish, which have excellent swimming capability and pressure-resistant structure, are studied. Swimming mechanism of squid/cuttlefish jetting and fin undulating propulsion is analyzed, and the equations of jet thrust, propulsive efficiency of jetting period and whole hydrodynamic propulsion cycle are given. The advantages of squid/cuttlefish compound swimming are good performance at both high and low speeds, being capable of changing swimming direction immediately, low noise, and that thrust can be generated even if jet velocity is slower than that of the surrounding fluid. In order to explain swimming mechanism in depth, the muscle arrangements and functions of mantle and fin muscular hydrostats, the two locomotory systems, are studied. The muscular hydrostats not only serve to the skeleton support of body, to carry out movement and to generate force, but also have considerable pressure-resistant capability. The hydrostatic pressure in and out of the mantle of most squid/cuttlefish is equal due to no gas filled tissue in their body, which improves their pressure-resistant capability further. During the movement, energetic efficiency is improved because energy is saved by the elastic spring mechanism. If the characteristics of swimming mechanism, muscular and elastic mechanism could be applied to biomimetic underwater robot, the robot would be more efficient, flexible and pressure-resistant.