四足哺乳动物疾驰机理若干问题

Based on the reasonable simplification of the mechanical model of bionic cheetah, the model of multi-elastic spine joint and virtual equivalent quadruped bionic cheetah is proposed. In order to provide mechanical theory for the research of mechanism of cheetah gallop gait and the realization of gallop gait in bionic cheetah robot, the research of the coupled model of the real forelimb, hindlimb and multi-elastic spine, also the real four-limb and multi-elastic spine bionic mechanical cheetah model is proceed. the movement procedure of cheetah gallop gait is divided into different section , and explained in successive-Poincare theory, so as to discuss the iteration convergence criteria of the successive Poincare map in transition gait and stable periodic gallop gait. On account of the solution set of successive-Poincare map, the discussion and planning of cheetah gallop gait is proceed, in order to provide effective method for stability analysis, allocation and optimization of joint drive energy and mechanism of cheetah gallop gait. The stability requirement and criterion in different segment of cheetah gallop gait. Introduce the geometric moment invariants to describe the steady state of the centroid,the movement of various components and the mechanical moment of force and energy moment are utilized to describe the energy distribution and energy-driven demand, and to achieve optimization of drive and energy distribution. The key parts of the experimental apparatus of the bionic cheetah are utilized to validate the theoretical mechanism or provide an analytical basis.

对仿生猎豹的机构学模型进行合理简化，提出多脊柱弹性关节-等效虚拟四足仿生猎豹机构学模型。研究猎豹真实前、后腿与具有多脊柱弹性关节的躯干耦联模型，将等效虚拟腿变换为真实四足-多脊柱关节猎豹机构学模型，为猎豹疾驰机理研究和仿生猎豹机器人疾驰步态运动实现提供机构学理论。将猎豹疾驰步态运动过程中的每一步幅按时间序列级联，用序列庞加莱映射描述，研究过渡步态和稳定周期性疾驰步态的序列庞加莱映射迭代收敛准则，基于序列庞加莱映射解集进行猎豹疾驰步态分析与规划，为猎豹疾驰步态稳定性分析、关节驱动能量的分配与优化、以及猎豹高速疾驰奔跑机理等研究提供有效方法。研究猎豹疾驰步态不同阶段相步态稳定性条件与准则。引入几何矩不变量描述质心的稳定状态，并且用各构件运动与受力的运动矩和力学矩、能量矩等描述系统的能量分布与能量驱动需求，实现驱动与能量分布优化。设计仿生机构的实验装置，对机理研究及相关分析进行验证或提供依据。

疾驰步态是四足哺乳动物及仿生四足机器人研究领域的重要组成部分，而猎豹是陆地上奔跑速度最快的四足哺乳动物，具有超高的奔跑速度和超强的爆发力，因此猎豹的生理学特点、身体结构和奔跑方式受到了国内外学者越来越多的关注。本项目通过对猎豹和马的骨骼肌结构进行合理的抽象和简化，分别建立了刚性躯干和四条无质量弹簧腿模型（BSL）、具有躯干关节和四条无质量弹簧腿的仿生动力学模型（BDM）和具有躯干关节和关节腿的仿生动力学模型（BDML）三种能够实现疾驰步态的被动动力学模型；分别提出了基于粒子群优化算法、基于牛顿拉夫逊方法的搜索方法和基于四阶龙格库塔方法的数值积分方法的庞加莱不动点搜索方法来实现稳定的疾驰步态；对比研究了猎豹和马的疾驰步态的内在疾驰机理，并同时对两类疾驰步态进行了无量纲模型的构建和综合性能分析；提出了猎豹疾驰步态稳定性准则和疾驰步态不稳定度的概念，基于稳定性准则提出了基于被动动力学模型和主动动力学模型的稳定性控制策略；基于猎豹在疾驰步态中所呈现出的躯干运动特点及其多关节协调机理，构建了具有仿生弹性脊椎关节的四足疾驰机器人实体样机，并通过实验对关键疾驰机理和稳定性准则进行了实验验证。本项目对不同类型四足哺乳动物疾驰步态的运动特点及疾驰机理进行深入分析，深入研究了猎豹疾驰步态的稳定性、超高爆发力和超高奔跑速度的机理，对仿生猎豹机器人实现高速疾驰步态提供重要的理论与实现依据。