13 accepted papers
Path planning is fundamental for controlling orthopedic robots and vital in ensuring surgical safety. To address the problem of low path-planning efficiency in traditional path planning methods, this work proposes an improved APF-RRT* algorithm for efficient path planning of fracture reduction. Firs
Nonlinear compliant actuators are being increasingly used in human-robot interaction scenarios due to their inherent flexibility. However, a limitation is that nonlinear hysteresis exists, which will degrade the force/torque tracking performance if the hysteresis is not modeled accurately. Moreover,
Gait phase detection is crucial to realize personalized assistive functions of lower limb exoskeletons. A common method in gait phase estimation is the adaptive oscillator, which performs well in periodic gaits. However, these types of methods fail in gait phase estimation under aperiodic gait cycle
Inspired by the bionic characteristics of ankle and calf skeletal muscles, a novel ankle-foot prosthesis (AFP) with variable stiffness mechanisms (VSMs) is proposed to assist transtibial amputees to restore ankle plantarflexion-dorsiflexion. The prosthesis is designed in the form of a spring-loaded
Due to intensive human-robot interaction in exoskeletons, it is desirable to design and control the exoskeletons with behavior compatible to human limbs to achieve natural and energy-efficient motion assistance. This requires both novel variable stiffness actuators and also technologies able to dete
A non-orthogonal frame is proposed in this work as an alternative representation of moving frames, which can describe naturally and conveniently orientations of the mobile platform of parallel pointing mechanisms. Fundamentals of non-orthogonal bases are presented, upon which a non-orthogonal frame
With the population of the world getting older and the working period becoming more extended, exoskeletons can be helpful to prevent occupational injuries and provide assistance for physically exhausting works. In this letter, a novel compact passive exoskeleton able to assist the elderly and worker
The article [1] neglects a relevant reference, namely, a patent about the spherical shoulder mechanism [2]. In this regard, the caption of Fig. 7 in [1] has been revised, which reads as:
A novel 6-DOF parallel manipulator with two spherical-universal-revolute limbs is proposed in this work. Compared with general 6-DOF parallel manipulators of six kinematic limbs, this new manipulator actuated by spherical motion generators has only two limbs, which brings kinematic advantages such a…
This paper presents a novel portable passive lower limb exoskeleton for walking assistance. The exoskeleton is designed with built-in spring mechanisms at the hip and knee joints to realize gravity balancing of the human leg. A pair of mating gears is used to convert the tension force from the built…
In this paper, a novel revolute joint of adjustable stiffness with reconfigurability (JASR) is presented. The JASR is designed with zero-length base link four-bar linkage, and allows adjusting its stiffness to achieve soft- and hard-spring behaviour. The new joint has a compact and light-weight stru…
This paper presents stiffness analysis of a family of three/four degree-of-freedom pick-and-place robots with four identical limbs. The Cartesian stiffness matrix of the robots is modeled with the virtual spring approach. By means of a nondimensionalization of the stiffness matrix, the 6 × 6 inhomog
This paper deals with the parametric optimum design of a parallel Schönflies-motion robot, named “Ragnar”, designed for fast and flexible pick-and-place applications. The robot architecture admits a rectangular workspace, which can utilize the shop-floor space efficiently. In this work, the parametr…