Abstract: Mechanisms to realize lightweight rotational joints having passive, high torque braking in one or more degrees of freedom are presented herein. In addition, robotic systems incorporating one or more rotational joints with passive, high torque braking as described herein are also presented. Each degree of freedom includes a spring element to preload the braking assembly to maintain high torque braking. The force generated by the spring is multiplied to a much larger force applied to the braking elements by a lever structure and an eccentric mechanism. A human user manually displaces the spring element and effectively reduces braking torque to a desired amount. In a further aspect, a two degree of freedom mechanical shoulder joint and brake device is disposed in a structural path between the harness assembly of an upper body support system and a surface of a working environment.

Abstract: Methods and system to partially support the weight of a human user engaged in task performance at ground level are presented herein. An upper body support system includes multiple degrees of freedom to adapt the physical geometry of the support system to meet the demands of the task at hand. Each degree of freedom of the upper body support system is passively controlled by the human user from a convenient user interface. In some embodiments, each end-effector of the support system is positioned and fixed in three degrees of freedom over a relatively large workspace by manually controlling the brake torque of two rotational joints and the state of a locking mechanism of a linear joint. In another aspect, an end-effector is removeably attached to the support system with a quick-change coupler. In some embodiments, a swivel joint mechanism compensates for misalignment with the work environment.

Abstract: Mechanisms to realize lightweight rotational joints having independently adjustable compliance in one or more degrees of freedom are presented herein. In addition, robotic systems incorporating one or more compliant rotational joints as described herein are also presented. In some embodiments, a robotic structure includes a member having adjustable rotational compliance. One or more compliance elements are arranged around a rotational joint. The position of the one or more compliance elements relative to the rotational joint is adjusted to change the overall joint compliance. In some embodiments, the change of position of the one or more compliance elements relative to the rotational joint changes both the induced displacement of the compliance element for a given angular displacement of the rotational joint and the length of the moment arm from the rotational joint to the compliance element.