Abstract: Wearable systems to partially support the weight of a human user engaged in task performance in a crouched position at or near ground level are presented herein. In one aspect, the wearable systems employ passive mechanisms and the configuration of the support mechanisms is changed by movements of the body of the human user while transitioning from a standing position to a crouched position, and vice-versa. In a further aspect, each passive lower body support assembly includes an auxiliary body support structure to enhance the support of the human user in a crouched position. In another further aspect, each auxiliary body support structure is deployed in coordination with the movement of the seat support structure that supports the human user. In some embodiments, one or more body support structures are constructed from an elastic material that conforms to the ground surface when loaded by the weight of the human user.

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.

Abstract: Methods and systems for seamlessly transitioning a load between two different actuators each having a different transmission ratio are described herein. A multiple drive, variable transmission ratio (MD-VTR) system includes two drive actuators, each having different reduction ratios, a locking mechanism, and a differential transmission subsystem. In one aspect, a MD-VTR system includes a locking mechanism disposed between a drive actuator and an input port of the differential. The locking mechanism couples the input port of the differential to a stationary reference frame element in a locked state. In an unlocked state, the locking mechanism couples the drive actuator to the input port of the differential. In some embodiments, the locking mechanism includes an actuator to actively transition between the locked and unlocked states. In some other embodiments, the locking mechanism transitions between the locked and unlocked states based on torque applied by the drive actuator.