Design and Kinematic Analysis of the Novel Almost Spherical Parallel Mechanism Active Ankle

A Survey on Design and Control of Lower Extremity Exoskeletons for Bipedal Walking

Exoskeleton robots are electrically, pneumatically, or hydraulically actuated devices that externally support the bones and cartilage of the human body while trying to mimic the human movement capabilities and augment muscle power. The lower extremity exoskeleton device may support specific human joints such as hip, knee, and ankle, or provide support to carry and balance the weight of the full upper body. Their assistive functionality for physically-abled and disabled humans is demanded in medical, industrial, military, safety applications, and other related fields. The vision of humans walking with an exoskeleton without external support is the prospect of the robotics and artificial intelligence working groups. This paper presents a survey on the design and control of lower extremity exoskeletons for bipedal walking. First, a historical view on the development of walking exoskeletons is presented and various lower body exoskeleton designs are categorized in different application areas. Then, these designs are studied from design, modeling, and control viewpoints. Finally, a discussion on future research directions is provided.

Inverse Kinematics of a Parallel Mechanism with an Offset Structural Design for Prosthetic Wrist Motions

Recent developments in upper limb wrist prosthetics allow for amputees to closely mimic the motions of a healthy human wrist. Although many active wrist prosthetics can flex and extend, relatively little work is done with their ability to pronate and supinate without the use of additional motors between the region where the forearm meets the hand. This paper reports a 3SPS-S-3RRR mechanism that provides quasi-spherical motions, mimicking a wrist's ability to flex and extend. It is also designed to offer rotational motion with offset Kresling arms to achieve motions conforming with pronation and supination. The paper explores the kinematics of the mechanism and introduces the use of motion capture acquisition in further studies.

Modular Design and Decentralized Control of the Recupera Exoskeleton for Stroke Rehabilitation

Robot-assisted therapy has become increasingly popular and useful in post-stroke neurorehabilitation. This paper presents an overview of the design and control of the dual-arm Recupera exoskeleton to provide intense therapist-guided as well as self training for sensorimotor rehabilitation of the upper body. The exoskeleton features a lightweight design, high level of modularity, decentralized computing, and various levels of safety implementation. Due to its modularity, the system can be used as a wheel-chair mounted system or as a full-body system. Both systems enable a wide range of therapies while efficiently grounding the weight of the system and without compromising the patient’s mobility. Furthermore, two rehabilitation therapies implemented on the exoskeleton system, namely teach & replay therapy and mirror therapy, are presented along with experimental results.