A Dynamic Spring-Charging Mechanism for Energetically Enhanced Locomotion

This dissertation focuses on the design and development of a dynamic spring-charging mechanism suitable for energetically enhanced locomotion. The mechanism employs high-speed mechanical logic, triggering a high-powered mechanical reflex that energizes the locomotion system with an undersized motor while out-of-contact with the environment. Before the actual linkage design of the mechanism is instantiated, the essential mechanism characteristics for dynamic spring-charging were investigated using a simulation framework where all physical mechanism parameters were excluded, concentrating instead on the dynamic utility of the linkage to be designed. This mechanismless simulation framework allowed us to determine the essential kinematic requirements and parameters of the to-be-designed linkage, and these kinematic requirements and parameters were used to synthesize the physical mechanism for dynamic spring-charging locomotion. Once synthesized and constructed, the mechanism was bolted to a benchtop to conduct inverted kicking experiments, affirming the outcomes from the mechanismless simulation study. Subsequently, the mechanism was mounted onto a pitch-constrained planarizing boom to perform hopping tasks while the motor receives constant torque signals, demonstrating its ability to not only offload repetitive subtasks of locomotion from conventional computer-actuator-sensor setups to mechanical processes, but enable a new capability that the standard setups alone cannot achieve: out-of-contact elastic energy accumulation & its automatic release upon contact, outputting 1.6 - 2 times the kinetic energy compared to the conventional points of comparison while maintaining a more consistent trajectory. Finally, using a purpose-built rigid body dynamic simulation framework, the effects of length scaling on the dynamic spring-charging mechanism are explored, showing that compared to conventional counterparts, the dynamic spring-charging mechanism demonstrates its superior power output regardless of scale, and the best normalized power output is found at 0.75 times the built size. By raising the robot's energetic profile without upsizing the motor, this work shows how the dynamic spring-charging mechanism for mechanical processing offers new capabilities beyond alleviating control tasks.

本论文聚焦于适用于能量增强式移动的动态储能弹簧机构（dynamic spring-charging mechanism）的设计与开发。该机构采用高速机械逻辑，触发高功率机械反射，可在与环境脱离接触的状态下，借助小型电机为移动系统赋能。在该机构的连杆机构（linkage）设计方案实体化之前，研究团队通过排除所有实体机构参数的仿真框架，对动态储能弹簧机构的核心特性展开研究，转而聚焦于待设计连杆机构的动态效用。该无实体机构仿真框架（mechanismless simulation framework）可帮助研究团队确定待设计连杆机构的核心运动学需求与参数，并基于这些运动学需求与参数构设出用于动态储能弹簧移动的实体机构。该机构构设并搭建完成后，被固定于实验台以开展反向踢动实验，验证了无实体机构仿真研究的结果。随后，该机构被安装于俯仰约束型平面悬臂以开展跳跃任务，此时电机接收恒定扭矩信号。实验结果表明，该机构不仅可将传统计算机-执行器-传感器系统中重复的移动子任务转移至机械流程中，还可实现传统单一系统无法达成的新功能：脱离接触时的弹性势能蓄积与接触时的自动释放，其输出动能为传统对照系统的1.6至2倍，同时保持更一致的运动轨迹。最后，研究团队借助定制化刚体动力学仿真框架（purpose-built rigid body dynamic simulation framework），探究了长度缩放对动态储能弹簧机构的影响。结果表明，相较于传统同类机构，无论尺寸如何缩放，该动态储能弹簧机构均展现出更优异的功率输出性能，且在原型尺寸的0.75倍时可实现最优归一化功率输出。本研究在不增大电机尺寸的前提下提升了机器人的能量性能，证明了用于机械流程的动态储能弹簧机构，除可减轻控制任务负担外，还能带来全新的功能与性能。