共查询到20条相似文献,搜索用时 15 毫秒
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Kostov A. Andrews B.J. Popovic D.B. Stein R.B. Armstrong W.W. 《IEEE transactions on bio-medical engineering》1995,42(6):541-551
Two machine learning techniques were evaluated for automatic design of a rule-based control of functional electrical stimulation (FES) for locomotion of spinal cord injured humans. The task was to learn the invariant characteristics of the relationship between sensory information and the FES-control signal by using off-line supervised training. Sensory signals were recorded using pressure sensors installed in the insoles of a subject's shoes and goniometers attached across the joints of the affected leg. The FES-control consisted of pulses corresponding to time intervals when the subject pressed on the manual push-button to deliver the stimulation during FES-assisted ambulation. The machine learning techniques used were the adaptive logic network (ALN) and the inductive learning algorithm (IL). Results to date suggest that, given the same training data, the IL learned faster than the ALN while both performed the test rapidly. The generalization was estimated by measuring the test errors and it was better with an ALN, especially if past points were used to reflect the time dimension. Both techniques were able to predict future stimulation events. An advantage of the ALN over the IL was that ALN's can be retrained with new data without losing previously collected knowledge. The advantages of the IL over the ALN were that the IL produces small, explicit, comprehensible trees and that the relative importance of each sensory contribution can be quantified 相似文献
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本文以三轴钻机床为研究对象,实现了机床的PLC控制系统设计。对PLC 控制系统中硬件的参数进行匹配,编写了机床定位模块的定位程序以及机床 PLC 的控制程序,实现了用 PLC 控制变频器对机床主轴无级调速,用定位模块对机床主轴的进给位置进行精确控制。 相似文献
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《Mechatronics》2023
The five-axis machine tool and industrial robot are two important systems in modern manufacturing systems. For accurate machining, the contouring control of these systems is essential. However, it is seldom studied in the literature. This is because of the unique features of such multi-axis motion systems: (1) they involve complicated kinematics; (2) not only contour error, but also orientation error should be minimized for the contouring control. In this paper, the iterative learning contouring control (ILCC) algorithm proposed previously by the authors will be applied to both the 5-axis machine tool and industrial robot. The control objective of the ILCC is the equivalent contour error, whose reduction is equivalent to the reduction of both contour error and orientation error. Moreover, the equivalent contour error can be easily constructed in the machine axis coordinates. Experiments on a commercial 5-axis machine tool and an industrial robot are conducted. It is found that either for the 5-axis machine tool or for the industrial robot, both the contour error and orientation error can monotonically converge almost at each time step, and the RMS contour error and orientation error can be reduced more than 90% after several learning iterations. The experimental results confirm the effectiveness of the proposed ILCC on the contouring control of both 5-axis machine tool and industrial robot. 相似文献
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Individual recognition from locomotion is a challenging task owing to large intra-class and small inter-class variations. In this article, we present a novel metric learning method for individual recognition from skeleton sequences. Firstly, we propose to model articulated body on Riemannian manifold to describe the essence of human motion, which can reflect biometric signatures of the enrolled individuals. Then two spatia-temporal metric learning approaches are proposed, namely Spatio-Temporal Large Margin Nearest Neighbor (ST-LMNN) and Spatio-Temporal Multi-Metric Learning (STMM), to learn discriminant bilinear metrics which can encode the spatio-temporal structure of human motion. Specifically, the ST-LMNN algorithm extends the bilinear model into classical Large Margin Nearest Neighbor method, which learns a low-dimensional local linear embedding in the spatial and temporal domain, respectively. To further capture the unique motion pattern for each individual, the proposed STMM algorithm learns a set of individual-specific spatio-temporal metrics, which make the projected features of the same person closer to its class mean than that of different classes by a large margin. Beyond that, we present a new publicly available dataset for locomotion recognition to evaluate the influence of both internal and external covariant factors. According to the experimental results from the three public datasets, we believe that the proposed approaches are both able to achieve competitive results in individual recognition. 相似文献
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在我国乒乓球被视为"国球",它也是一项老少皆宜的健身运动项目,为了让学习者更好地练习乒乓球,根据乒乓球发球技术特点,我们发明了一种自动乒乓球发球机,本文针对自动乒乓球发球机设计及其控制系统进行了研究探索。 相似文献
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Arena P. Fortuna L. Frasca M. Patane L. 《IEEE transactions on circuits and systems. I, Regular papers》2005,52(9):1862-1871
In this paper, the paradigm of emergent computation is applied to locomotion control in legged robots: the locomotion gait is the result of self-organization of a network of locally coupled nonlinear oscillators. This means to adopt the biological paradigm of central pattern generator (CPG), implemented by using cellular neural networks (CNNs). The whole control strategy is hybrid in the sense that the gait generation is accomplished by a fully analog CNN, while a simple logic unit modulates the behavior of the CNN-based CPG, so that the strategy is suitable to eventually include sensory feedback. The design of a VLSI chip implementing the CNN-based CPG and some experimental results on the chip are presented. The chip is designed using a switched-capacitor technique, fundamental to obtain in a simple and direct way some key features of the hybrid control discussed. The experimental results confirm the suitability of the approach. 相似文献
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自动药片装瓶机,是对不同形状的药片进行计数、装瓶的专用设备。采用西门子S7-200PLC技术,实现装瓶机的启动、停止以及中途改变装填粒数的功能。在分析装瓶机系统工艺过程和控制要求的基础上,进行PLC硬件和软件设计,经上机模拟调试,调试结果与实际控制要求一致。本装瓶机控制系统具有药片数量显示功能、装瓶速度快、计数准确、线路简洁、控制灵活的优点。 相似文献
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自动药片装瓶机,是对不同形状的药片进行计数、装瓶的专用设备.采用西门子S7-200PLC技术,实现装瓶机的启动、停止以及中途改变装填粒数的功能.在分析装瓶机系统工艺过程和控制要求的基础上,进行PLC硬件和软件设计,经上机模拟调试,调试结果与实际控制要求一致.本装瓶机控制系统具有药片数量显示功能、装瓶速度快、计数准确、线路简洁、控制灵活的优点. 相似文献
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现代工业自动化控制中.通过PLC/DCS实现数字化控制越来越普遍。将一些典型的过程控制抽象为简单的数学算法,将数学模型应用于控制方法教学中,可使教学生动且具有实践性,同时也可增强学生对控制实现过程的理解。 相似文献
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现代工业自动化控制中,通过PLC/DCS实现数字化控制越来越普遍.将一些典型的过程控制抽象为简单的数学算法,将数学模型应用于控制方法教学中,可使教学生动且具有实践性,同时也可增强学生对控制实现过程的理解. 相似文献
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A new algorithm is presented for chip-in-the-loop learning of the synchronous Boltzmann machine, which has two distinct advantages: it allows optimal use of analogue circuit dynamic range, unlike the conventional learning algorithm, and it features a coherent dual weight representation, which improves learning efficiency 相似文献
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Cilla M Martínez J Peña E Martínez MÁ 《IEEE transactions on bio-medical engineering》2012,59(4):1155-1161
Atherosclerotic cardiovascular disease results in millions of sudden deaths annually, and coronary artery disease accounts for the majority of this toll. Plaque rupture plays main role in the majority of acute coronary syndromes. Rupture has been usually associated with stress concentrations, which are determined mainly by tissue properties and plaque geometry. The aim of this study is develop a tool, using machine learning techniques to assist the clinical professionals on decisions of the vulnerability of the atheroma plaque. In practice, the main drawbacks of 3-D finite element analysis to predict the vulnerability risk are the huge main memories required and the long computation times. Therefore, it is essential to use these methods which are faster and more efficient. This paper discusses two potential applications of computational technologies, artificial neural networks and support vector machines, used to assess the role of maximum principal stress in a coronary vessel with atheroma plaque as a function of the main geometrical features in order to quantify the vulnerability risk. 相似文献
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Glassey C.R. Shanthikumar J.G. Seshadri S. 《Semiconductor Manufacturing, IEEE Transactions on》1996,9(4):536-549
We consider the problem of reducing the cycle time required for producing wafers at a given rate in high-volume single-product semiconductor fabs. Based on theoretical results, we propose a new method of input control that uses intersecting hyperplanes to decide when to release a new lot into the wafer fab. The release control rules constructed thus are said to belong to the class of linear control rules. We provide numerical examples to demonstrate that our method gives nearly optimal results for flowline and probabilistic reentrant flowline models. We then propose the linear control rule called descending control (DEC) and give a hybrid simulation-optimization procedure for determining DEC rules in real-life settings. We provide numerical results for the HP development fab model of Wein 相似文献
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Wei L Yang Y Nishikawa RM Wernick MN Edwards A 《IEEE transactions on medical imaging》2005,24(10):1278-1285
Clustered microcalcifications (MC) in mammograms can be an important early sign of breast cancer in women. Their accurate detection is important in computer-aided detection (CADe). In this paper, we propose the use of a recently developed machine-learning technique--relevance vector machine (RVM)--for detection of MCs in digital mammograms. RVM is based on Bayesian estimation theory, of which a distinctive feature is that it can yield a sparse decision function that is defined by only a very small number of so-called relevance vectors. By exploiting this sparse property of the RVM, we develop computerized detection algorithms that are not only accurate but also computationally efficient for MC detection in mammograms. We formulate MC detection as a supervised-learning problem, and apply RVM as a classifier to determine at each location in the mammogram if an MC object is present or not. To increase the computation speed further, we develop a two-stage classification network, in which a computationally much simpler linear RVM classifier is applied first to quickly eliminate the overwhelming majority, non-MC pixels in a mammogram from any further consideration. The proposed method is evaluated using a database of 141 clinical mammograms (all containing MCs), and compared with a well-tested support vector machine (SVM) classifier. The detection performance is evaluated using free-response receiver operating characteristic (FROC) curves. It is demonstrated in our experiments that the RVM classifier could greatly reduce the computational complexity of the SVM while maintaining its best detection accuracy. In particular, the two-stage RVM approach could reduce the detection time from 250 s for SVM to 7.26 s for a mammogram (nearly 35-fold reduction). Thus, the proposed RVM classifier is more advantageous for real-time processing of MC clusters in mammograms. 相似文献