Analysis of the gait generation principle by a simulated quadruped model with a CPG incorporating vestibular modulation
Analysis of the gait generation principle by a simulated quadruped model with a CPG incorporating vestibular modulation
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DOI：
10.1007/s00422-013-0572-4
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发表时间：
2013-12-01
影响因子：
1.9
通讯作者：
Fukui, Takahiro
中科院分区：
文献类型：
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作者：
Fukuoka, Yasuhiro;Habu, Yasushi;Fukui, Takahiro
本研究旨在了解四足模型中步态生成的原理。简单地通过观察由大脑、神经、肌肉等组成的复杂动物的运动很难确定步态产生的本质。因此，我们建立了一个简化了神经系统和机构的平面四足动物模型，以观察其步态仿真。该模型配备了一个数学的中央模式发生器（CPG），由四个耦合的神经振荡器，基本上产生小跑模式。该模型还包含对CPG的感觉反馈，测量身体倾斜（前庭调制）。除了中速小跑外，这会自发地引起低速时的非程序性横向行走，跑步时的横向疾驰。这是因为身体振荡在低速时表现出每条腿频率的双峰，在中速时没有峰值（小振荡），而在跑步时表现出单峰。身体振荡通过反馈自主地调整神经振荡器之间的相位差。我们假设由CPG产生的四条腿的振荡和根据当前速度变化的身体振荡与变化的相位差沿着同步，以在运动期间通过经由前庭调制的姿势适应来保持平衡，从而产生每个步态。我们成功地确定了一个简单的原则，即使没有大脑控制，复杂的腿部机制或灵活的躯干，也可以解释从步行到小跑再到飞奔的步态转变。
This study aims to understand the principles of gait generation in a quadrupedal model. It is difficult to determine the essence of gait generation simply by observation of the movement of complicated animals composed of brains, nerves, muscles, etc. Therefore, we build a planar quadruped model with simplified nervous system and mechanisms, in order to observe its gaits under simulation. The model is equipped with a mathematical central pattern generator (CPG), consisting of four coupled neural oscillators, basically producing a trot pattern. The model also contains sensory feedback to the CPG, measuring the body tilt (vestibular modulation). This spontaneously gives rise to an unprogrammed lateral walk at low speeds, a transverse gallop while running, in addition to trotting at a medium speed. This is because the body oscillation exhibits a double peak per leg frequency at low speeds, no peak (little oscillation) at medium speeds, and a single peak while running. The body oscillation autonomously adjusts the phase differences between the neural oscillators via the feedback. We assume that the oscillations of the four legs produced by the CPG and the body oscillation varying according to the current speed are synchronized along with the varied phase differences to keep balance during locomotion through postural adaptation via the vestibular modulation, resulting in each gait. We succeeded in determining a single simple principle that accounts for gait transition from walking to trotting to galloping, even without brain control, complicated leg mechanisms, or a flexible trunk.