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In order to make full use of the ability of the low impact docking mechanism to reduce the contact force in the docking process, the impedance control strategy is designed. And then a kind of parameter adjusting flow is proposed for the impedance controller based on the influence rules of the target impedance. To perform a low impact docking mission unaware of the initial position error and orientation...
A novel, homogeneous and continuous analytical model of cyclist pedaling torque angular distribution is presented in the article. The model is dedicated for use in an unique pedaling-by-wire system. The motivation to the research is to obtain a model for use in control system with compensation. Applying nonlinear compensation of cyclist load torque results in pedals speed ripples reduction — particularly...
A parallel mechanism has advantages such as high stiffness, low inertia and compact in size. It is a desired mechanical structure to be used as the mini manipulator in a macro-mini manipulator system. In this paper, a 3-DOF parallel mechanism is presented. The end-effector module will serve as the mini manipulator in a macro-mini system for in-contact industrial finishing applications such as polishing...
The hydrodynamic performance of a hinge-connected flexible fin is studied by fluid-structure interaction in this paper. The fin consists of two links, namely, the leading link and tailing link, with various flexibilities. Firstly, the leading link moves with scheduled equation while the tailing link is uncontrolled and subjected to passive motion. The fluid and structure responses of five flexibility...
Flexible new micro/nanomanipulation tools are required to intuitively perform micro/nano operations without the need for expensive, bespoke tools. In this paper, the design and analysis of a dexterous 4 degree of freedom (DOF) hybrid serial-parallel micro/nanomanipulator is presented. The manipulator is controlled through a haptic device, enabling a trained user to control the system's motion, and...
The design of an effective knee-motion actuator for active lower-extremity exoskeletons (LEEs) is challenging due to the stringent requirements to adapt to human kinematics and cooperate with human behavior. This paper presents a method for designing an electromagnetic knee-motion actuator that compensates for the dynamics of the combined lower-leg/link and is capable of adapting to the kinematics...
This paper presents an innovative design concept for an underactuated robotic finger which can perform adaptable closure and pinch grasping. The mechanically simple design combines an underactuated spring-loaded enclosing mechanism with a Variable Stiffness Actuator, which can be used to regulate the mechanical stiffness and interaction forces of the finger during grasping. This highly desirable property...
Locomotion maneuvers over irregular terrains involve complex forces and movements that make estimation of center of mass(CoM) behavior a challenging task. Nevertheless, understanding CoM dynamics remains pivotal in locomotion planning for both humans and robots. Current methods for CoM position estimation rely heavily on expensive and ungainly tools, for example force plates, that render CoM analysis...
This paper considers the problem of Collision Free Force Closure Workspace (CFFCW) determination for Reconfigurable Planar Cable-Driven Parallel Robots (RPCDPRs). The cluttered obstacles in environment and the radiate cable structure make this problem highly nontrivial. Firstly, the simplified model of general RPCDPR that with cluttered environment is proposed. Then, the critical support lines of...
Market forecasts for the civilian use of unmanned aerial vehicles (UAVs) show a sustained growth in the long term. To increase awareness for operators, a three degree-of-freedom haptic interface is introduced to provide helpful operational assistance for UAV motion control. Furthermore, an adjustable feedback is implemented in the interface with different combinations of force. In this paper, the...
In this paper, the problem of time-optimal path tracking is investigated for coordinated dual-robot system. In the case of dual-robot system carrying on coordinated manipulation process with simplified physical constraints, a sequential convex programming (SCP) framework is implemented to realize time optimality. Moreover, versatile optimization objective functions for coordinated dual-robot system...
The bevel-tip flexible needle is an improvement of the clinical puncture needle and has the potential to reduce surgery traumas and improve puncture accuracy. Due to the nonholonomic kinematics model, it is difficult to drive flexible needles to a target precisely. In this paper, a driving method is proposed to steer flexible needles to a target in 3-D environment without obstacles. In addition, a...
This paper presents an extended kinematics and dynamics of the articulated tracked vehicles (ATV) used in many applications. The velocity of the front and the rear vehicle are firstly analysed and the kinematics of ATV is built, according to which the steer radius and the track velocity can be obtained. Then we analyse the force and moment acting on the ATV running on the firm ground and the soft...
This paper presents an underactuated finger mechanism enabling both self-adaptive grasping and natural motion such as flexion and extension. It has three degrees-of-freedom mechanism composed of one actuator and a couple of passive components including torsional springs and mechanical stoppers. In detail, the proposed mechanism consists of two five-bar and one four-bar linkages. Since each five-bar...
This paper presents the design and simulation of an ankle-foot orthosis (AFO) to assist human walking. Design requirements were established based on a quantitative study of published data, simulations of human walking, and a model of intrinsic and reflex ankle joint stiffness. The design of an AFO that meets these requirements is then presented; it comprises a small linear, hydraulic actuator, a servo-valve,...
Center of Mass(CoM) estimation in rough terrains is hampered by complicated body dynamics yet remains critically important in the study of human and robot motion planning. Current techniques for CoM estimation are encumbered by lengthy calibration periods requiring the use of specialized tools(force plates, motion capture, etc). This paper presents a novel and straightforward geometric method for...
Since trunk function plays a major role in propulsion in sit-skiers and athletes belonging to distinct classes have different abilities to control trunk muscles, the aim of this study is to evaluate how athletes personalized their skiing strategy to compensate their impairment and improve skiing effectiveness. Sixteen Paralympic sit-skiers belonging to different classes volunteered as participant...
Ultrasound imaging procedures are deemed as one of the most convenient and least invasive medical diagnostic imaging modalities and have been widely utilized in health care providers, which are expecting semiautomatic or fully-automatic imaging systems to reduce the current clinical workloads. This paper presents a portable and wearable soft robotic system which has been designed with the purpose...
This paper presents an optimal internal model control (OIMC) algorithm for heading control problem of underactuated AUV systems affected by wave disturbances. Firstly, the AUV nonlinear system model is converted to the system model by differential homeomorphism. And the exosystem of wave force disturbances is obtained based on the Morison equation. Secondly, the disturbances compensator is designed...
The article deals with the application of the method for mathematical modeling and simulation at solving some issues in the area of electrostatic technology. It focuses on the processes in electrostatic separation and precipitation. Computer simulation is highly required in equipment design and their diagnostics in critical operating states using theoretical calculations and experimental data evaluation...
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