| 摘要: | 本論文提出一個方法來設計實現一台大型人形機器人的下半身。本論文是以高度130公分之人形機器人為最終的設計目標，所完成之下半身的高度及重量分別為89公分及47公斤。共有12個自由度，左右腳各有6個自由度，其中髖關節、膝關節及踝關節分別有3個、1個及2個自由度。本論文使用直流無刷馬達與減速機來讓各個關節具有較大的扭力輸出。在機器人機構的設計上，主要有兩項：(1)骨骼設計和(2)緩衝設計。在骨骼設計中，位於大腿骨的部分有往內彎折些許角度，這個彎折的角度並不是人類特有而是生物演化而成，經統計彎折的角度平均約為6度，這樣的角度可以讓人類的重心偏移較為迅速，用於人形機器人設計上能讓行走的穩定度更高。在緩衝設計中，在大腿機構和小腿機構之間加上氣壓棒來做為緩衝以及輔助扭矩的設計。在蹲下時，氣壓棒會有向上的推力來幫忙緩衝向下的扭矩，其可以避免突然過大的力道會造成減速機的損壞；在站立時，氣壓棒會有向上的推力來幫忙輔助向上的扭矩，其可以減少馬達所要承受的負載。由實驗結果可知，本論文所實現的大型雙足機器人可呈現重心偏移、起立及蹲下等動作。
In this thesis, a method is proposed to design and implement a lower body mechanism of an adult-sized biped robot. The final objective is to build up a humanoid robot with 130 cm tall. Its high and weight of the implemented lower body is 89 cm and 47 kg, respectively. There are 12 degrees of freedom (DOFs) for the biped robot and 6 DOFs for each leg. For each leg, there are 3 DOFs, 1 DOFs, and 2 DOFs in the hip joint, the knee joint, and the ankle joint, respectively. One DC brushless motor with one decelerator are combined to increase its torque of each joint. In the mechanical design of robot, there are two main parts: (1) skeleton design and (2) cushion design. In the skeleton design, the bone of thigh bends inward a few angles. The bending angle is not unique for humans but biological evolution. Statistically, the averaged of bending angle is around 6 degrees, which can make center of mass shift fast when the human walks. In the cushion design, the gas spring is used for the buffer and the auxiliary torque between thigh and shank mechanism. When the robot squats, the gas spring, which has upward thrust to reduce downward torque, can avoid sudden excessive force to cause decelerator damage. Also, when the robot stands up, the gas spring can reduce the load of motors. Some experimental results are presented to illustrate the implemented adult-sized biped robot could do some movements of weight shiftting, standing up, and squating. |
