检索结果-内蒙古大学图书馆

Initialization Concepts for Optimal control of Hybrid Systems

IFAC Proceedings Volumes 2011年第1期44卷 10274-10280页

作者： Benjamin Passenberg Magnus Kröninger Georg Schnattinger Marion Leibold Olaf Stursberg Martin Buss Institute of Automatic Control Engineering Technische Universität München Munich Germany Institute for High-Frequency Engineering Technische Universität München Munich Germany Institute of Control and System Theory University of Kassel Kassel Germany

Abstract Indirect methods solve optimal control problems for hybrid systems with high precision, but they are difficult to initialize. To overcome the initialization difficulties, two different concepts based on direct methods are presented. In the first approach, the hybrid optimal control problem is solved by a direct method until the precision is sufficient for a successful initialization of the indirect method. The second approach decomposes the hybrid optimal control problem into non-hybrid subproblems, where each subproblem can be initialized separately by a direct method. This results in a significantly higher robustness of the initialization compared to the first approach. However, the precision of the solution with the indirect method achieved in the first approach is higher. The two concepts are compared in a numerical example.

关键词： optimal control hybrid systems initialization indirect optimization methods autonomous vehicles

来源：评论

学校读者我要写书评

暂无评论

Knowledge-based Artificial Fish-Swarm algorithm

Knowledge-based Artificial Fish-Swarm algorithm

引用

作者： Wu, Ying Gao, Xiao-Zhi Zenger, Kai Control Theory and Engineering Department Harbin Institute of Technology Harbin 150001 China Department of Automation and Systems Technology Aalto University School of Electrical Engineering Espoo P.O.BOX 15500 FI-00076 Aalto Finland

ISBN: (纸本)9783902661937

In this paper, a knowledge-based Artificial Fish-Swarm (AFA) optimization algorithm with crossover, CAFAC, is proposed to enhance the optimization efficiency and combat the blindness of the search of the AFA. In our CAFAC, the crossover operator is first explored. The knowledge in the Culture Algorithm (CA) is next utilized to guide the evolution of the AFA. Both the normative knowledge and situational knowledge is used to direct the step size as well as direction of the evolution in the AFA. Ten high-dimensional and multi-peak functions are employed to investigate this new algorithm. Numerical simulation results demonstrate that it can indeed outperform the original AFA. © 2011 IFAC.

关键词： Knowledge based systems

来源：评论

学校读者我要写书评

暂无评论

Observer-based inverse hysteresis control of prototypical magnetic shape memory (MSM) actuator

Observer-based inverse hysteresis control of prototypical ma...

引用

International Conference on Mechatronics (ICM)

作者： Michael Ruderman Torsten Bertram Institute of the Control Theory and Systems Engineering Technische Universität Dortmund Dortmund Germany

The magnetic shape memory (MSM) alloys are well-promising for the controlled magnetic field-induced motion. This paper describes the observer-based inverse hysteresis control of a prototypic MSM based actuating element The MSM induced motion is a novel and challenging topic for mechatronics due to a high integrity of the magnetic and mechanical components as well as a complex nonlinear dynamic behavior to be controlled. A highly hysteretic and thereto non-deterministic (to the certain degree) response of the field-induced strain is the main challenge when regulating the MSM generated motion. The way, how the MSM type actuators can be controlled robustly using the observer-based inverse hysteresis approach is described and shown with experiments.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Observer-based control strategies for compensation of dynamic friction

Observer-based control strategies for compensation of dynami...

引用

Mediterranean Conference on control and Automation (MED)

作者： Michael Ruderman Torsten Bertram Institute of Control Theory and Systems Engineering Technische Universität Dortmund Dortmund Germany

This paper describes and compares different observer-based control strategies for compensating the dynamic friction in controlled motion systems. The once identified system with friction requires usually an observer due to unknown disturbances and time variant friction behavior. The recently developed two-state dynamic friction model with elasto-plasticity is applied within three different types of observer, all involved in the control loop. Each of the observer-based compensation schemes as well as the friction model in feed-forwarding augments a standard linear feedback velocity control which serves for evaluation as the reference one. The performance of the realized control approaches is evaluated on an ordinary electro-mechanical actuator system with multiple coupled sources of friction without its direct measurement.

关键词： Friction Observers Modeling Dynamics Trajectory Predictive models Actuators

来源：评论

学校读者我要写书评

暂无评论

On system-oriented modeling and identification of magnetic shape memory (MSM) actuators

On system-oriented modeling and identification of magnetic s...

引用

Mediterranean Conference on control and Automation (MED)

作者： Michael Ruderman Torsten Bertram Institute of Control Theory and Systems Engineering Technische Universität Dortmund Dortmund Germany

The magnetic shape memory (MSM) alloys are interesting candidates among active materials used in the actuators, particularly due to a macroscopic relationship between the applied magnetic field and the resulting MSM strain. A system oriented description of MSM actuators is quite challenging caused by the inherently nonlinear hysteretic behavior of the MSM transducer. This paper describes a modeling and identification approach which combines the second-order linear actuator dynamics with the novel two-inputs nonlinear MSM model. The proposed identification strategy allows to decompose the linear and nonlinear effects observable in the actuator response under certain excitation conditions. The experimental evaluation performed on a prototypic MSM actuator reveals the model suitability, particularly by capturing the state-dependent memory phenomena of MSM hysteresis.

关键词： Actuators Magnetic hysteresis Strain Magnetomechanical effects Hysteresis Perpendicular magnetic anisotropy

来源：评论

学校读者我要写书评

暂无评论

Ensemble of Experts for Robust Floor-Obstacle Segmentation of Omnidirectional Images for Mobile Robot Visual Navigation

Ensemble of Experts for Robust Floor-Obstacle Segmentation o...

引用

2011 IEEE International Conference on Robotics and Automation(2011年IEEE世界机器人与自动化大会 ICRA 2011)

作者： Luis Felipe Posada Krishna Kumar Narayanan Frank Hoffmann Torsten Bertram Institute of Control Theory and Systems Engineering Technische Universit¨at Dortmund44227DortmundGermany

This paper presents a novel approach for floor obstacle segmentation in omnidirectional images which rests upon the fusion of multiple classification generated from heterogeneous segmentation schemes. The individual naive Bayes classifiers rely on different features and cues to determine a pixel’s class label. Ground truth data for training and testing the classifiers is obtained from the superposition of 3D scans captured by a photonic mixer device camera. The classification is supported by edge detection which indicate the presence of obstacles and sonar range data. The complementary expert decisions are aggregated by stacked generalization, behavior knowledge space or voting combination. The combined floor classifier achieves a classification accuracy of up to 0.96 true positive rate with only 0.03 false positive rate. A robust robot navigation is accomplished by arbitration among a reactive obstacle avoidance and a corridor following behavior using the robots local free space as perception.

关键词： Image segmentation Histograms Sonar Robots Training Image edge detection Navigation

来源：评论

学校读者我要写书评

暂无评论

Robustness of prediction based delay compensation for nonlinear systems

Robustness of prediction based delay compensation for nonlin...

引用

作者： Findeisen, Rolf Grüne, Lars Pannek, Jürgen Varutti, Paolo Otto-von-Guericke-Universität Magdeburg Institute for Automation Engineering Department of Systems Theory and Automatic Control Germany University of Bayreuth Institute of Mathematics Department of Applied Math. Germany Curtin University of Technology Perth Australia

ISBN: (纸本)9783902661937

control of systems where the information between the controller, actuator, and sensor can be lost or delayed can be challenging with respect to stability and performance. One way to overcome the resulting problems is the use of prediction based compensation schemes. Instead of a single input, a sequence of (predicted) future controls is submitted and implemented at the actuator. If suitable, so-called prediction consistent compensation and control schemes, such as certain predictive control approaches, are used, stability of the closed loop in the presence of delays and packet losses can be guaranteed. In this paper, we show that control schemes employing prediction based delay compensation approaches do posses inherent robustness properties. Specifically, if the nominal closed loop system without delay compensation is ISS with respect to perturbation and measurement errors, then the closed loop system employing prediction based delay compensation techniques is robustly stable. We analyze the influence of the prediction horizon on the robustness gains and illustrate the results in simulation. © 2011 IFAC.

关键词： Closed loop systems

来源：评论

学校读者我要写书评

暂无评论

Vehicle-License-Plate Recognition Based on Neural Networks

Vehicle-License-Plate Recognition Based on Neural Networks

引用

第八届IEEE信息与自动化国际会议(ICIC 2011)

作者： Dong Wei YiQing Liu Ning Zhang MinZhe Zhao Control Theory and Control Engineering Beijing Institute of Civil Engineering and Architecture Xiche Tianjin KuGe technology Co. LTD Haidian DistrictBeijingChina

ISBN: (纸本)9781457702686

A license plate recognition system based on neural networks was designed and *** system used a neural-network chip to recognize license *** chip combined video image processing module with neural network module by using equalized image processing algorithm and network classification algorithm.A set of interface circuit was developed for implementing license-plate-number *** results show the system can guarantee a very low error rate at an acceptable recognition time.

关键词： FPGA Neural networks Vehicle license plate recognition Neural network license plate recognition system interface circuit VIDEO IMAGES network-on-chip

来源：评论

学校读者我要写书评

暂无评论

Scenario and context specific visual robot behavior learning

Scenario and context specific visual robot behavior learning

引用

2011 IEEE International Conference on Robotics and Automation(2011年IEEE世界机器人与自动化大会 ICRA 2011)

作者： Krishna Kumar Narayanan Luis Felipe Posada Frank Hoffmann Torsten Bertram Institute of Control Theory and Systems Engineering Technische Universit(a)t Dortmund44227DortmundGermany

The design of visual robotic behaviors constitutes a substantial challenge. It requires to draw meaningful relationships and constraints between the acquired visual perception and the geometry of the environment both empirically and programmatically. This contribution proposes a novel robot learning framework to classify and acquire scenario specific autonomous behaviors through demonstration. During demonstration, robocentric 3D range and omnidirectional images are recorded as training instances of typical robot navigation situations pertaining to different contexts in multiple indoor scenarios. A programming by demonstration approach generalizes the demonstrated trajectories to a general mapping between visual features extracted from the omnidirectional image onto a corresponding robot motion. The approach is able to distinguish among different traversing scenarios and further identifies the best matching context within the scenario to predict an appropriate robot motion. As a comparison to context matching, the behaviors are trained by means of an artificial neural network and its generalization ability is evaluated against the former. The experimental validation on the mobile robot indicates that the acquired visual behavior is robust and generalizes meaningful actions beyond the specific environments and scenarios presented during training.

关键词： Robots Trajectory Context Training Visualization Collision avoidance Artificial neural networks

来源：评论

学校读者我要写书评

暂无评论

Optimized Distributed control and Network Topology Design for Interconnected Systems

Optimized Distributed Control and Network Topology Design fo...

引用

IEEE Conference on Decision and control

作者： Dominic Gross Olaf Stursberg Institute of Control and System Theory Department of Electrical Engineering and Computer Science University of Kassel (Germany)

ISBN: (纸本)9781612848006

This paper considers optimized network topology design and distributed control for linear discrete-time systems consisting of subsystems interconnected through states, inputs, and a cost function. By using a distributed control law, which makes use of the communicated states of other subsystems, closed-loop performance is increased at the expense of communication costs. This raises the question of how to find a topology and associated distributed control law with optimal trade-off between communication costs and closed-loop performance. As an answer to this question, we propose an approach to simultaneous optimization of network topology and control law with respect to a cost function which combines a quadratic performance criterion with costs associated to the presence of communication links. The problem is formulated as mixed-integer semi-definite problem (MISDP) where the discrete optimization of the network topology subject to communication constraints and embedded subproblems for structured controller synthesis lead to an upper bound for the combined cost. An example is used to illustrate the method.

关键词： Network topology decentralised control control law Cost functions Performance metrics Communication Research SUB-SYSTEM large-scale systems closed-loop performance

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：