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This paper proposes an online compensation method of gravity and friction by least squares method (LSM) for robots implementing haptics. In order to expand the range of tasks using the robot such as telepresence robot, implementing haptics technology is essential. However, with higher gear ratio motors, the friction lowers the quality of the haptic transmission. In order to comfortably control the...
This paper describes the design of a control strategy for robotic rehabilitation devices, aimed at recovering the motor skills of patients affected by particular diseases that damage the neuromuscular apparatus of the human body. There are two different but related activities in the project here described. At first, a non-linear parameter identification procedure, based on the Recursive Least Square...
Welding is an important operation in manufacturing processes and it can represent a highly relevant amount of production costs, depending on material workpieces and required weld quantity. In mechanised and robotised welding processes, robot's travel velocity is an important parameter, which requires a proper regulation to obtain a good quality for weld beam. Then, in this work, a nonlinear model...
The robotic welding processes have been highly widespread in manufacturing industries due to large-scale production. An area where these processes are widely applied are shipyards, where there are necessary hundreds to thousands of kilograms of weld by hour. However, systems that operate in open-air environments are vulnerable to sundry disturbances, noises in measures, as well as possible unavailability...
The reducing of energy consumption for transportation and manipulation of industrial objects is a topical issue. The objects of manipulation are gripped with the use of industrial robot and transported from one position to another. In gripping devices, the lifting force is created on the basis of the aerodynamic effect of lifting appearing due to the use of compressed air. The efficiency of functioning...
The servo motion system plays an important role in the position accuracy of the Cartesian picking robot. During the automatic picking process, the nonlinearity of friction will affect position tracking accuracy. In order to improve the position accuracy of Cartesian robot, a mechanical model considering friction is established. Furthermore, fuzzy logic controller based on PID is used to control the...
The authors have studied a motion generation by a wobbling mass attached in the center of a semicircular-shaped body, and showed that generation of a downward motion on a downhill is possible through 4-DOF 1-input underactuated-system with 1-DOF linkage inside the body. The system is, however, difficult to generate a forward motion on level surface. Currently, the authors set the trajectory of the...
Simulation of the planar magnetic actuation of ferromagnetic bodies is proposed and experimentally verified in the framework of the system for precise positioning of miniature passive robots with two degrees of freedom. Major goal of presented development is to balance computational effort of the simulation with complexity of computational problem. Proposed methodology is developed for efficient simulation...
We perform a comparative analysis of energy-based performance criteria for the dynamics-based optimization of robot trajectories. The performance criteria considered include minimum torque, electrical power loss, approximation to mechanical work, and energy loss due to friction. Our dynamics model takes into account rotor inertias and gearing, and also considers robots subject to a range of motion...
In this study, we developed a wall-climbing robot for airplane body inspection. To move on airplane body, the robot needs to move on walls and curved surfaces. A traveling-wave-type, omnidirectional wall-climbing robot that uses magnetic force to adhere could move on such a wall and curved surface. However, magnetic force cannot be used to adhere to airplane body. Therefore, we developed a wall-climbing...
The authors showed that an underactuated locomotion robot can generate a stable forward motion on downhill by utilizing the effects of sliding and wobbling. It was, however, difficult to generate forward motion on level surface. Our next research objective is therefore achieving stable motion generation on slippery level surface. It is being developed that a new type of the robot utilizing wobbling...
In this work, we consider a testbed for a robotic astronomical 0.5-m. telescope mount. We focus on the problem of identification uncertainty that cannot be obtained from analytical consideration (i.e. friction phenomena). Thus, we use a recursive least-squares algorithm for identification values of friction terms. Since the required signals cannot be obtained directly from the object (or they are...
The improvement of movement smoothness over the course of therapy is one of the positive outcomes observed during robotic rehabilitation. Although movements are generally robust to disturbances, certain perturbations might disrupt an individual's ability to produce these smooth movements. In this paper, we explore how a rehabilitation robot's inherent dynamics impact movement smoothness during pointing...
Torque limiters are a proven way to enhance the safety in robots. To further increase the safety, adjustable torque limits depending on the task and the joint configuration (joint angles, velocity, acceleration) would be preferable. Friction clutches can be used as adjustable torque limiters (ATL). In contact free motion the ATL can be set with torque limits higher than the required torque, thereby...
In recent years, ventilation equipment has been installed in various structures to draw in outdoor air and circulate indoor air. These ventilation installations have pipes (ducts) through which air flows. If dust accumulates in a duct, it will be carried indoors by the airflow. Dust adversely affects human health, and so these ducts must be cleaned regularly. However, the existing cleaning methods...
Robotic devices have been clinically verified for use in long duration and high intensity rehabilitation needed for motor recovery after neurological injury. Targeted and coordinated hand and wrist therapy, often overlooked in rehabilitation robotics, is required to regain the ability to perform activities of daily living. To this end, a new coupled hand-wrist exoskeleton has been designed. This paper...
This present work provides over discussion about the component and requirement of space tribology. And Pin-on-disk test is described to prove the effect on the solid lubrication under the high vacuum condition. This paper will discuss the following: space mechanism components, solid lubrication, and factors affecting wear phenomenon under the high vacuum.
The identification procedure specially designed for an n-link inverted pendulum on a cart is presented. By the Lagrangian mechanics, the mathematical model of the n-link inverted pendulum is established initially. To fully model the system, the standard dynamic parameters which are some algebraic functions of geometric, inertial, and friction parameters are introduced. Because the dynamic model of...
Mechanics-based formulations of concentric tube robots incorporate tube bending and twisting, but do not include other phenomena that could model observed hysteretic behavior in which tube configurations reached by rotating tubes in different directions achieve different tip positions. As a step toward incorporating hysteretic tube-on-tube friction, this paper derives a model that enables computation...
Grasping an object in the presence of unpredictable disturbances and with no previous knowledge of the geometry and mass distribution of it represents a significant challenge in Robotics. Also, grasping an object with sufficient force to prevent slippage, whilst not damaging or deforming the shape of the object proves to be still an intricate challenge despite the existence of a huge body of literature...
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