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In this paper, an impedance control strategy is proposed for a rigid robot collaborating with human by considering impedance learning and human motion intention estimation. The least square method is used in human impedance identification, and the robot can adjust its impedance parameters according to human impedance model for guaranteeing compliant collaboration. Neural networks (NNs) are employed...
Dexterous object manipulation requires suitable control of grip force, load force and digit positions. To keep an object stable in the air, force magnitude, force direction and digit positions should be coordinated, producing compensatory torque that could balance the external torque and maintain a minimal object roll. Six males and 6 females enrolled in the study. In the experiment, subjects were...
Compliance control using tactile sensor for robotic hands have been one of the major research topics. Most researchers use a variety of multi-dimensional force sensors with compliance control. In this paper, we replace traditional multidimensional force/torque sensor with one-dimensional pressure sensor. In order to achieve the effect of multi-dimensional sensor, we also propose a vector decomposer...
Due to the great performance in complex and narrow spaces, snake-like robots, especially snake arm robots, have gained increasing attention in recent years. In this paper, a novel cable-driven snake arm robot is proposed. For greater flexibility, the snake arm not only has multiple two-degree-of-freedom joints, but also has telescopic modules that have one degree of freedom. The kinematics and statics...
Aiming at the security problem of cooperative robots, this paper presents a low cost collision detection algorithm without torque sensors. In this method, the collision can be detected with the sampling torque and the dynamic model. First, the relationship between the output torque and the motion state of the rotating joint of the robot is established according to the Newton Euler method. For the...
In order to accurately simulate vehicles' running states of lane changing and more effectively reflect its characteristics, based on the driving experience, this paper introduced three changing rules and their corresponding lane changing benefits and safety factors, and summarized the lateral and longitudinal motion of vehicles as the interaction result between lane changing benefits and safety factors...
In this paper we presented the functional analysis of intelligent wheelchair, and proposed system configuration program. The working principle of the ultrasonic sensor system is expounded. We researched the method of path planning and random avoidance, and achieve environment modeling and path planning. Link Graph method is used for modeling whole environment and Dijkstra arithmetic is used to established...
The collision avoidance problem of autonomous ships is analyzed in this paper. Firstly, the background and the difficulties are reviewed. Then an improved artificial potential field method is designed to solve the collision avoidance problem of unmanned ships, and the system characteristics are investigated. Finally, simulation results demonstrate the ship's control effectiveness in the obstacle environment.
We proposed a hybrid powered ankle exoskeleton. It can be able to supply positive mechanical power to the user during the swing phase of gait. The hybrid powered ankle exoskeleton was composed of a pair of compressed springs and a cable-driven actuator fasted to the shin. It was lightweight, and permitted the cable-driven actuator to provide the forces at the biological level to the ankle joint. Meanwhile...
The purpose of this study was to explore the relationship between grip strength and inter-muscular coordination of the forearms and hands. Twenty-four healthy young volunteers participated in the experiment. The subjects were instructed to grip hydraulic hand dynamometer with five force levels-maximal voluntary contraction (MVC), 70% MVC, 50% MVC, 30% MVC and without any contraction. Muscle activity...
In this paper, we proposed a sensor structure that can be used to measure the tactile force of robot fingertip. The structure of the sensor was composed of a cylinder-shaped finger and a circular base. First, we analyzed the relationship between the contact position and the stress with elastic mechanics theory. Then the corresponding spline curve algorithm was designed to calculate the contact position...
A method utilizing one Phase-shifted Fiber Bragg Grating (PS-FBG) and adaptive particle swarm optimization (APSO) algorithm has been proposed to simultaneously measure the spatial multiple axial stresses, including axial stress and transversal stress. The swarm success rate based dynamic adaptive strategy for the adjusting of inertia weight has been introduced to balance the exploration and exploitation...
The thumb and index finger are important digits to performed dexterous and complex manipulation of objects. However, the local muscle fatigue will induce the capacity of force production and impair the precision motor control of the thumb and index finger. This study focused on the exercise-induced local muscle fatigue influencing the COP (center of pressure) area, the SD and the PA (projection angle)...
The postural instability was observed in patients following-stroke during standing, showing an altered center of mass acceleration (COMacc). This study aimed to investigate the effects of stroke on fluctuation and complexity of COMacc during quiet standing. Eleven stroke survivals and eleven gender- and age-matched healthy subjects participated in this experiment. The COMacc series in anteroposterior...
In this paper, one fiber Bragg grating (FBG) vibration sensor is proposed and the application of weak signal processing based on Duffing oscillator model in optical fiber vibration sensors is studied. Frequency response and amplitude sensitivity experiments are all carried out to verify the characteristics of this FBG vibration sensor. By calculating the maximum Lyapunov exponent, these experiment...
We establish the dynamics relative to flapping angle of the flapping wing vehicle based on the quasi-steady aerodynamics model and Newton-Euler motion equations, and describe the stability analysis method of linearized perturbation equation under active control by varying flapping frequency based on the Routh-Hurwitz stability criterion. To give a demonstration, we design a flapping wing mechanism...
The design employs direct drive torque motor to achieve a robot single joint with active compliance based on the impedance model. In order to maximize the torque density, transmission transparency and backdrivability, the joint employs a quasi-direct actuator that a single-stage planetary gear is mounted on the motor's rotor. When robot interacts with environments, it's inevitable to change the stiffness...
To solve the problem of joint speed and strength of electricity controlled flexible clutch system (DMT) in the buses, the paper proposed a control method of pulse width modulation (PWM) based on the Freescale of 16-bit MC9S12XEP100 microcontroller. Designed the DMT control circuit and used the PID control of exciting current. The test results show that PWM control solved the rapid joint lead to overshoot,...
Unwanted residual vibration in dynamic system always causes many problems in industrial manufacturing. For instance, it is difficult for a crane to transport a heavy cargo to a specified location safely, quickly and accurately in the case of oscillation. In this paper, the crane system is simplified as a rail trolley hoisting system where the payload is a rod, and an input shaping method is investigated...
A maglev wind yaw system (MWYS) is proposed to decrease the yaw power with the hybrid magnet. A disc motor and a variable speed gear are introduced to weaken the coupling between the suspension force and yaw torque. Firstly, we analyze the operation principal of the MWYS, and give the detailed description of the suspension weight and rotary torque. The rotor ample turns are given based on the Magnet...
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