This paper presents a trajectory generation algorithm for a three-dimensional (3D) biped robot that can adjust the center of mass (CoM) according to the environment. We adopt a new abstract model that supports vertical motion and rotation. Differing from traditional abstract models, the proposed full centroid dynamics inverted pendulum model fully considers the robot’s movement and rotation. Unlike the zero moment point (ZMP), which only ensures the feet do not flip over, we also propose a new additional stability criterion, named zero frictional moment point (ZFMP), guaranteeing no yaw rotation while walking. Next, a nonlinear model predictive control is designed to generate the CoM trajectory, torso rotational angle, and adaptive footholds to induce various biped gaits. A full-dynamics 3D humanoid robot is simulated to test the proposed method while steering, walking underneath a low door, and walking with disturbances.

中文翻译：

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三维变质心高度双足行走采用新模型和非线性模型预测控制

本文提出了一种三维（3D）双足机器人的轨迹生成算法，可以根据环境调整质心（CoM）。我们采用了一种新的抽象模型，支持垂直运动和旋转。与传统的抽象模型不同，所提出的全质心动力学倒立摆模型充分考虑了机器人的运动和旋转。与仅确保脚不翻转的零力矩点（ZMP）不同，我们还提出了一种新的附加稳定性准则，称为零摩擦力矩点（ZFMP），保证行走时不会偏航旋转。接下来，设计非线性模型预测控制来生成 CoM 轨迹、躯干旋转角度和自适应立足点，以诱导各种两足步态。对全动态 3D 人形机器人进行了仿真，以在转向、在低门下行走以及在干扰下行走时测试所提出的方法。