This paper analyzes the comfort of wheelchair users when a sliding-mode trajectory-tracking controller is used. The transmission of the horizontal (fore-and-aft) vibration to the head-neck complex (HNC) in the seated ...
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ISBN:
(纸本)9789898111319
This paper analyzes the comfort of wheelchair users when a sliding-mode trajectory-tracking controller is used. The transmission of the horizontal (fore-and-aft) vibration to the head-neck complex (HNC) in the seated human body may cause unacceptable discomfort and motion sickness. A double-inverted pendulum model with two degrees of freedom is considered as a model for the HNC. The user comfort is examined not only in the time domain (using the fourth power vibration dose value), but also in the frequency domain (using the cross-spectral density method). For measuring the acceleration of the wheelchair, along the trajectory, an inertial measurement unit was used.
Compliant mechanisms have been used in several robotics applications, including locomotion and grasping. Variable stiffness joints are part of these compliant mechanisms and generally use one passive element per joint...
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ISBN:
(纸本)9798331517519;9798331517526
Compliant mechanisms have been used in several robotics applications, including locomotion and grasping. Variable stiffness joints are part of these compliant mechanisms and generally use one passive element per joint. This paper presents the design, model, and characterization of a Variable Stiffness Multi-joint Mechanism (VSMM) using a single carbon fibre rod as its passive element. The VSMM employs a variable lever mechanism, allowing the modulation of the joints' stiffness. We present an analytical model of the mechanism, providing insights into its mechanical behaviour and enabling the prediction of stiffness variations under different design parameters. Through experimental testing, the mechanism demonstrates a stiffness range of 0.19N/ mm to 0.27N/ mm, offering variable compliance that can change to suit specific task requirements.
Passively compliant drives are interesting alternatives to classical stiff actuators in emerging fields like human- robot cooperation, service and rehabilitation robotics. Pneumatic muscles have been found to be inter...
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ISBN:
(纸本)9789898565211
Passively compliant drives are interesting alternatives to classical stiff actuators in emerging fields like human- robot cooperation, service and rehabilitation robotics. Pneumatic muscles have been found to be interesting low-cost actuators for such purposes. To fully realize the (desired) higher sensitivity and at the same time maintain a good control quality, detailed models of the robot's own components are required. For pneumatic muscles, their hysteresis characteristic is a challenging property. In this paper we present a hysteresis model based on a Prandtl-Ishlinskii operator approach and evaluate the resulting performance when the inverse model is used for compensation in the position controller. The evaluation is done on a real multi-axes robot arm.
This paper discusses the placement of cameras in order to achieve the highest possible localization accuracy. It is reached by using several cameras with redundant fields of views. A camera model is introduced and the...
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ISBN:
(纸本)9789897580406
This paper discusses the placement of cameras in order to achieve the highest possible localization accuracy. It is reached by using several cameras with redundant fields of views. A camera model is introduced and the components which cause the localization errors are identified. The localization accuracy measure is defined for one and for multiple cameras too. The problem of adding a new camera to the system in order to improve the accuracy is formulated. The method for finding the optimal placement of this new camera is presented. Some features are enumerated which can be applied for getting an advanced method.
Vectorization is a widely used technique in many areas, mainly in robotics and image processing. Applications in these domains frequently require both speed (for real-time operation) and accuracy (for maximal informat...
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ISBN:
(纸本)9789897581984
Vectorization is a widely used technique in many areas, mainly in robotics and image processing. Applications in these domains frequently require both speed (for real-time operation) and accuracy (for maximal information gain). This paper proposes an optimization for the high speed vectorization methods, which leads to nearly optimal results. The FTLS algorithm uses the total least squares method for fitting the lines into the point cloud and the presented augmentation for the refinement of the results, is based on a modified Nelder-Mead method. As shown on several experiments, this approach leads to better utilization of the information contained in the point cloud. As a result, the quality of approximation grows steadily with the number of points being vectorized, which was not achieved before. Performance costs are still comparable to the original algorithm, so the real-time operation is not endangered.
Simulation frameworks are wide-spread in the range of robotics to test algorithms and analyze system behavior beforehand - which tremendously reduces effort and time needed for conducting experiments on the real machi...
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ISBN:
(纸本)9789898565716
Simulation frameworks are wide-spread in the range of robotics to test algorithms and analyze system behavior beforehand - which tremendously reduces effort and time needed for conducting experiments on the real machines. This paper addresses a component based framework for simulating a wall-climbing robot that uses negative pressure adhesion in combination with an omnidirectional drive system. Key aspect is the adhesion system which interacts with the environmental features such as surface characteristics (e. g. roughness) or defects. An elaborate thermodynamic model provides the basis for a realistic simulation of the airflow between the virtual environment and the vacuum chambers of the robot. These features facilitate the validation of closed-loop controllers and control algorithms offline and in realtime.
CREA robot is designed to climb up concrete walls. The robot uses the suction mechanism to provide adhesion and wheel mechanism for locomotion. Eleven chambers which are connected to one common reservoir are responsib...
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ISBN:
(纸本)9789897580406
CREA robot is designed to climb up concrete walls. The robot uses the suction mechanism to provide adhesion and wheel mechanism for locomotion. Eleven chambers which are connected to one common reservoir are responsible to produce adhesion force. A controller is developed to independently control each chamber while satisfying certain criteria on the safety of the robot. It is also designed to reach minimum friction between active inflatable seals and wall. In conclusion, the controller is able to successfully meet the conditions of stability, minimum friction and safety.
An overview is given on the integration of product modeling with robot control. A method to enhance application of geometric and other product and production equipment related information in robot control is introduce...
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An overview is given on the integration of product modeling with robot control. A method to enhance application of geometric and other product and production equipment related information in robot control is introduced. Focus is on creation and application of model data information understandable by robot controls, on communication of model data with robot environments through the Internet, and finally on some related telerobotics issues.
In this research, we focus on the 6D pose estimation of known objects from the RGB image. In contrast to state of the art methods, which are based on the end-to-end neural network training, we proposed a hybrid approa...
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ISBN:
(纸本)9789897583803
In this research, we focus on the 6D pose estimation of known objects from the RGB image. In contrast to state of the art methods, which are based on the end-to-end neural network training, we proposed a hybrid approach. We use separate deep neural networks to: detect the object on the image, estimate the center of the object, and estimate the translation and "in-place" rotation of the object. Then, we use geometrical relations on the image and the camera model to recover the full 6D object pose. As a result, we avoid the direct estimation of the object orientation defined in SO3 using a neural network. We propose the 4D-NET neural network to estimate translation and "in-place" rotation of the object. Finally, we show results on the images generated from the Pascal VOC and ShapeNet datasets.
The proceedings contain 219 papers. The topics discussed include: hamiltonian of line graph under condition of constraint;the performance persistence of mutual fund: the empirical research based on cross-sectional reg...
ISBN:
(纸本)9783642259913
The proceedings contain 219 papers. The topics discussed include: hamiltonian of line graph under condition of constraint;the performance persistence of mutual fund: the empirical research based on cross-sectional regression;a driving method of the electro hydraulic proportional valve based on compensation network;the structure and realization of a compactweeding robot in stamping mode for paddy fields;study on the identification of noise sources and reducing noise for diesel engine;the design of UART controller based on FPGA;synchronization of fractional-order chaotic system with application to communication;design of temperature measuring and controlling system based on STM32;expert-system-based design of large networks of deployable mechanisms;and a heuristic algorithm for the initial codebook design in vector quantization.
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