While many advancements have been made in the development of template models for describing upright-trunk locomotion, the majority of the effort has been focused on the stance phase. In this paper, we develop a new compact dynamic model as a first step toward a fully unified locomotion template model (ULT-model) of an upright-trunk forward hopping system, which will also require a unified control law in the next step. We demonstrate that all locomotion subfunctions are enabled by adding just a point foot mass and a parallel leg actuator to the well-known trunk SLIP model and that a stable limit cycle can be achieved. This brings us closer toward the ultimate goal of enabling closed-loop dynamics for anchor matching and thus achieving simple, efficient, robust and stable upright-trunk gait control, as observed in biological systems.

翻译：尽管在描述直立躯干运动的模板模型开发方面已取得诸多进展，但大部分研究集中在支撑阶段。本文首次提出一种新型紧凑动力学模型，作为直立躯干前向跳跃系统完全统一运动模板模型（ULT-模型）的第一步，后续还需建立统一控制律。我们证明，仅在著名的躯干SLIP模型基础上增加点足质量和平行腿部执行器，即可实现所有运动子功能，并达到稳定极限环。这使我们更接近最终目标：实现锚点匹配的闭环动力学，从而获得如生物系统般简单、高效、鲁棒且稳定的直立躯干步态控制。