The authors developed an experimental methodology to determine the friction forces and friction coefficient in dry and lubricated conditions between steel cylinder and some types of polyurethanes. The method consists ...
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This paper studies the walking robot hybrid dynamic control in real time in order to increase movement stability of walking robots on flat terrain, with obstacles or uneven ground, at constant or variable walking spee...
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This paper studies the walking robot hybrid dynamic control in real time in order to increase movement stability of walking robots on flat terrain, with obstacles or uneven ground, at constant or variable walking speed and variable load. The motion trajectory positions of the robot leg end-effect or and joints, reaction forces and the walking robot dynamics are analyzed and the virtual projection method is adopted using the Versatile Intelligent Portable Robot Platform VIPRO. The obtained results lead to higher performance in relation to the walking robots movement possibilities, the real-time robot balance control, gait control and predictable motion control, providing increased mobility and stability, and also the development of new technological capabilities of the control systems.
This work focuses on proposing and designing a new climbing robot to explore the interiors of industrial vessels and enables a human outside the vessels to implement required regular inspection tasks efficiently. Ther...
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This work focuses on proposing and designing a new climbing robot to explore the interiors of industrial vessels and enables a human outside the vessels to implement required regular inspection tasks efficiently. There are two main adhesion systems in the literature: magnetic and air suction systems. The magnetic system climbs surfaces made of ferromagnetic materials only, while air suction system cannot handle irregular surfaces due to possible seals damage. Opposite to previous climbing robots, the proposed robot here can climb and navigate vessels made from different materials besides handling possible irregular surfaces during inspection. Its main task is visual inspection of welds and any critical spots inside these vessels. The novelty of this robot comes from utilizing a hybrid actuation system. This hybrid actuation system consists of upturned propellers fixed on mobile robot and motorized wheels of the mobile robot. The pressure generated from the upturned propellers increase the friction force between the wheels of the mobile robot and the wall. The wheels' motors generate the required torque either to fix the robot in any position or to move it to any place. Since the motion of the robot comes mainly from the motorized wheel, the stability of the system during navigation is guaranteed. Size and topology optimizations are carried out to achieve optimum design of the proposed robot. Simulation results of the designed robot using ADAMS software prove its feasibility.
This paper presents results of experimental investigation of the falling down of human body in order to identify significant characteristics and parameters that help for safe similar situations with humanoid robots. E...
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This paper presents results of experimental investigation of the falling down of human body in order to identify significant characteristics and parameters that help for safe similar situations with humanoid robots. Experiments are discussed with results from lab tests that give both behavior and values of the biomechanics of falling down of human body. Simulations of humanoid robot falling verified the strategies concluded from the human falling down.
Artificial tactile feedback systems is now emerging as an essential part in laparoscopic surgeries. This paper presents a new structure for a micro tactile sensor, whose output does not depend on the applied pushing d...
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ISBN:
(纸本)9781467380843
Artificial tactile feedback systems is now emerging as an essential part in laparoscopic surgeries. This paper presents a new structure for a micro tactile sensor, whose output does not depend on the applied pushing distance or the contact angle with the tissue. The sensor structure is based on using three silicon cantilevers in one plane, acting as three springs with different stiffness, which are protected by square PDMS diaphragms. A detailed design has been executed to achieve high sensitivity and linearity. A finite element simulation was implemented to validate the design and sensor performance. Different values have been assigned to the tissue Young's modulus (up to 1 MPa) covering different organisms. The results show that the sensor can differentiate between different types of tissues based on their modulus of elasticity. The sensor output was demonstrated to be independent of neither the pushing distance nor the contact angle up to (±3 degree). The error of the mean value of output due to the inclination angle did not exceed 3.5%.
This paper presents two methods, non-contact low frequency ultrasound method and fiber Bragg gratings, and their application to nondestructive testing of glass fiber reinforced composites used in wind turbine blades. ...
This paper presents two methods, non-contact low frequency ultrasound method and fiber Bragg gratings, and their application to nondestructive testing of glass fiber reinforced composites used in wind turbine blades. Theoretical models are used and experimental results are in good concordance with destructive testing results.
CFRP have applications among most different domains due their low density, high elastic modulus and high ultimate strength along the carbon fibers direction, no fatigue and the expansion coefficient is small. This pap...
CFRP have applications among most different domains due their low density, high elastic modulus and high ultimate strength along the carbon fibers direction, no fatigue and the expansion coefficient is small. This paper presents the behavior of carbon fiber woven-PPS composites at low velocity impacts. The transversal electrical conductivity is modified due to the plastic deformation following the impacts, and thus electromagnetic procedures can be used for assessment of CFRP using a high resolution sensor with metamaterials lens and comparing the results with those obtained from ultrasound testing with phased array sensor. The area of the delamination is overestimated when the method of phased array ultrasound is used and substantially underestimated by the electromagnetic testing. There were a good agreement between the simulations with finite element method and experimental measurements.
作者：
M. HypiusováV. VeselýInstitute of Automotive Mechatronics
Faculty of Electrical Engineering and Information Technology Slovak University of Technology Ilkovičova 3 812 19 Bratislava Slovak Republic Institute of Robotics and Cybernetics
Faculty of Electrical Engineering and Information Technology Slovak University of Technology Ilkovičova 3 812 19 Bratislava Slovak Republic
We present a new technique for the synthesis of a robust model predictive controller with infinite prediction horizon. The proposed controller design approach ensures a parameter-dependent quadratic stability and guar...
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We present a new technique for the synthesis of a robust model predictive controller with infinite prediction horizon. The proposed controller design approach ensures a parameter-dependent quadratic stability and guaranteed cost for linear polytopic uncertain systems. The proposed design procedure based on BMI or LMI reduces to off-line output feedback controller gain calculation minimizing an upper bound on the “worst case” an objective function. For the case of our approach and input (output) constraints at each sample time step for each input (output) scalar parameter is calculated, which radically decreases the computational load. The controller design is illustrated by examples.
This paper presents the development and implementation of laser interferometry-based sensing and measurement for precise localisation of multirotor helicopters. A sliding mode-based control architecture is developed i...
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ISBN:
(纸本)9781479977970
This paper presents the development and implementation of laser interferometry-based sensing and measurement for precise localisation of multirotor helicopters. A sliding mode-based control architecture is developed incorporating position measurements from the laser measurement system. The control architecture facilitates the auto-alignment of a laserbeam emanating from the laser measurement system and a retroreflector mounted on the target multirotor helicopter. The dynamics model of the multirotor helicopter is developed in order to define the sliding-mode based control law to effectuate position and motion control. A computational analysis of the computational stability of the control algorithm is performed. Further, an experimental research facility is established with a 4-rotor multirotor helicopter and a laser interferometry-based sensing and measurement system. Experimental analysis offers evidence that the sliding mode-based control architecture is able to maintain incident laser-beam and retroreflector alignment, facilitating continuous, real-time precise position measurements. It is further demonstrated that the sliding mode-based control architecture outperforms a proportional-derivative-based control architecture delivering the same functionality.
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