Self-localization is a fundamental requirement for the mobile robot. Robot usually contains a large number of dif- ferent sensors, which provide the information of robot localization, and all the sensor information sh...Self-localization is a fundamental requirement for the mobile robot. Robot usually contains a large number of dif- ferent sensors, which provide the information of robot localization, and all the sensor information should be considered for the optimal location. Kalman filter is efficient to realize the information fusion. Used as an efficient sensor fusion algorithm, Kalman filter is an advanced filtering technique which can reduce errors of the position and orientation of the sensors. Kalman filter has been paied much attention to robot automation and solutions to solve uncertainties such as robot localization, navigation, following, tracking, motion control, estimation and prediction. The paper briefly describes Kalman filter theory, and establishes a simple mathematical model based on muti-sensor mobile robot. Meanwhile, Kalman filter is used in robot self-localization by simulations, and it is demonstrated by simulations that Kalman filter is effective.展开更多
A constructive method was presented to design a global robust and adaptive output feedback controller for dynamic positioning of surface ships under environmental disturbances induced by waves, wind, and ocean current...A constructive method was presented to design a global robust and adaptive output feedback controller for dynamic positioning of surface ships under environmental disturbances induced by waves, wind, and ocean currents. The ship's parameters were not required to be known. An adaptive observer was first designed to estimate the ship's velocities and parameters. The ship position measurements were also passed through the adaptive observer to reduce high frequency measurement noise from entering the control system. Using these estimate signals, the control was then designed based on Lyapunov's direct method to force the ship's position and orientation to globally asymptotically converge to desired values. Simulation results illustrate the effectiveness of the proposed control system. In conclusion, the paper presented a new method to design an effective control system for dynamic positioning of surface ships.展开更多
In the traditional Intemet Protocol （IP） architecture, there is an overload of IP sermntic problems. Existing solutions focused mainly on the infrastructure for the fixed network, and there is a lack of support for ...In the traditional Intemet Protocol （IP） architecture, there is an overload of IP sermntic problems. Existing solutions focused mainly on the infrastructure for the fixed network, and there is a lack of support for Mobile Ad Hoc Networks （MANETs）. To improve scalability, a routing protocol for MANETs is presented based on a locator named Tree-structure Locator Distance Vector （TLDV）. The hard core of this routing method is the identifier/locator split by the Distributed Hash Table （DHT） method, which provides a scalable routing service. The node locator indicates its relative location in the network and should be updated whenever topology changes, kocator space ks organized as a tree-structure, and the basic routing operation of the TLDV protocol is presented. TLDV protocol is compared to some classical routing protocols for MANETs on the NS2 platform Results show that TLDV has better scalability. Key words：展开更多
A practical serf-localization scheme for mobile robots is proposed and implemented by utilizing sonar sensors. Specifically, the localization problem is solved by employing Monte Carlo method with a new mechanism prop...A practical serf-localization scheme for mobile robots is proposed and implemented by utilizing sonar sensors. Specifically, the localization problem is solved by employing Monte Carlo method with a new mechanism proposed to calculate the samples＇ weights; the convergence and veracity of the sample set are guaranteed by the designed resampling and scattering process. The proposed serf-localization algorithm is fully implemented on a specific mobile robot system, and experimental results illustrate that it provides an efficient solution for the kidnapped problem.展开更多
Mobile robot navigation in unknown environment is an advanced research hotspot.Simultaneous localization and mapping(SLAM)is the key requirement for mobile robot to accomplish navigation.Recently,many researchers stud...Mobile robot navigation in unknown environment is an advanced research hotspot.Simultaneous localization and mapping(SLAM)is the key requirement for mobile robot to accomplish navigation.Recently,many researchers study SLAM by using laser scanners,sonar,camera,etc.This paper proposes a method that consists of a Kinect sensor along with a normal laptop to control a small mobile robot for collecting information and building a global map of an unknown environment on a remote workstation.The information(depth data)is communicated wirelessly.Gmapping(a highly efficient Rao-Blackwellized particle filer to learn grid maps from laser range data)parameters have been optimized to improve the accuracy of the map generation and the laser scan.Experiment is performed on Turtlebot to verify the effectiveness of the proposed method.展开更多
Using sensor and GPS to make a trajectory planning for the stationary obstacle, autonommus mobile robot can asstmae that it is placed at the center of the map, and from the distance information between autonomous mobi...Using sensor and GPS to make a trajectory planning for the stationary obstacle, autonommus mobile robot can asstmae that it is placed at the center of the map, and from the distance information between autonomous mobile robot and obstacles. But in case of active moving obstacle, many components and information need to process since their moving trace should be considered in real time. This paper mobile robot＇s driving algorithm of unknown dynamic envirormaent in order to drive intelligently to destination using ultrasonic and Global Positional Systern （GPS）. Sensors adjusted the placement dependment on driving of robot, and the robot plans the evasion method according to obstacle which are detected by sensors. The robot saves GPS coordinate of complex obstacle. If there are many repeated driving, robot creates new obstacles to the hr, ation by itself. And then it drives to the destination resolving a large range of local minirmnn point If it needs an intelligent circtmtantial decision, a proposed algorithm is suited for effective obstacle avoidance and arrival at the destination by performing simulations.展开更多
The autonomous navigation of an electric vehicle requires the implementation of a number of sensors and actuators intended to inform it about his environment or his position and velocity and deliver necessary inputs. ...The autonomous navigation of an electric vehicle requires the implementation of a number of sensors and actuators intended to inform it about his environment or his position and velocity and deliver necessary inputs. That＇s why it is important to detect and locate sensor and actuator faults as soon as possible to enable the operator to run the vehicle in degraded mode or use the fault tolerant control system if it exists. The main purpose of this paper deals with sensors or actuators faults diagnosis of autonomous vehicle. A diagnosis method using a nonlinear model of the vehicle is developed. Nonlinear state space model of the autonomous electric vehicle is used with the method of nonlinear analytical redundancy to detect and to isolate faults occurred on sensors or actuators. Computer simulations are carried out to verify the effectiveness of the method.展开更多
An accurate low-cost ultrasonic localization system is de- veloped for automated mobile robots in indoor environments, which is essential for automatic navigation of mobile robots with various tasks. Although ultrasen...An accurate low-cost ultrasonic localization system is de- veloped for automated mobile robots in indoor environments, which is essential for automatic navigation of mobile robots with various tasks. Although ultrasenic sensors are more cost-effective than other sensors such as Laser Range Finder （LRF） and vision, but they are inaccurate and directionally ambiguons. First, the matched filter is used to measure the distance accurately. For resolving the computational complexity of the matched filter, a new matched filter algorithm with simple compution is proposed. Then, an ultrasonic localization system is proposed which consists of three ultrasonic receivers and two or mote transmitters for improving position and orientation accuracy was developed. Finally, an extended Kalman filter is designed to estimate both the static and dynamic positions and orientations. Various simu lations and experimental results show that the proposed system is effective.展开更多
Severe sex ratio imbalance at birth is now becoming an important issue in several Asian countries. Its leading immediate cause is prenatal sex-selective abortion following illegal sex identification by ultrasound scan...Severe sex ratio imbalance at birth is now becoming an important issue in several Asian countries. Its leading immediate cause is prenatal sex-selective abortion following illegal sex identification by ultrasound scanning. In this paper, a fast automatic recognition and location algorithm for fetal genital organs is proposed as an effective method to help prevent ultrasound technicians from unethically and illegally identifying the sex of the fetus. This automatic recognition algorithm can be divided into two stages. In the 'rough' stage, a few pixels in the image, which are likely to represent the genital organs, are automatically chosen as points of interest (POIs) according to certain salient characteristics of fetal genital organs. In the 'fine' stage, a specifically supervised learning framework, which fuses an effective feature data preprocessing mechanism into the multiple classifier architecture, is applied to every POI. The basic classifiers in the framework are selected from three widely used classifiers: radial basis function network, backpropagation network, and support vector machine. The classification results of all the POIs are then synthesized to determine whether the fetal genital organ is present in the image, and to locate the genital organ within the positive image. Experiments were designed and carried out based on an image dataset comprising 658 positive images (images with fetal genital organs) and 500 negative images (images without fetal genital organs). The experimental results showed true positive (TP) and true negative (TN) results from 80.5% (265 from 329) and 83.0% (415 from 500) of samples, respectively. The average computation time was 453 ms per image.展开更多
基金Research Fund for the Doctoral Program of Higher Education of China(No.20123718120007)
文摘Self-localization is a fundamental requirement for the mobile robot. Robot usually contains a large number of dif- ferent sensors, which provide the information of robot localization, and all the sensor information should be considered for the optimal location. Kalman filter is efficient to realize the information fusion. Used as an efficient sensor fusion algorithm, Kalman filter is an advanced filtering technique which can reduce errors of the position and orientation of the sensors. Kalman filter has been paied much attention to robot automation and solutions to solve uncertainties such as robot localization, navigation, following, tracking, motion control, estimation and prediction. The paper briefly describes Kalman filter theory, and establishes a simple mathematical model based on muti-sensor mobile robot. Meanwhile, Kalman filter is used in robot self-localization by simulations, and it is demonstrated by simulations that Kalman filter is effective.
文摘A constructive method was presented to design a global robust and adaptive output feedback controller for dynamic positioning of surface ships under environmental disturbances induced by waves, wind, and ocean currents. The ship's parameters were not required to be known. An adaptive observer was first designed to estimate the ship's velocities and parameters. The ship position measurements were also passed through the adaptive observer to reduce high frequency measurement noise from entering the control system. Using these estimate signals, the control was then designed based on Lyapunov's direct method to force the ship's position and orientation to globally asymptotically converge to desired values. Simulation results illustrate the effectiveness of the proposed control system. In conclusion, the paper presented a new method to design an effective control system for dynamic positioning of surface ships.
基金Acknowledgements This work was supported by the Hi-Tech Research and Development Program of China under Grant No.2007AA01Z407 the Co-Funding Project of Beijing Municipal education Commission under Grant No.JD100060630+3 种基金 National Foundation Research Project the National Natural Science Foundation Project under Grant No. 61170295 the Project of Aeronautical Science Foundation of China under Caant No.2011ZC51024 and the Fundamental Research Funds for the Central Universities.
文摘In the traditional Intemet Protocol （IP） architecture, there is an overload of IP sermntic problems. Existing solutions focused mainly on the infrastructure for the fixed network, and there is a lack of support for Mobile Ad Hoc Networks （MANETs）. To improve scalability, a routing protocol for MANETs is presented based on a locator named Tree-structure Locator Distance Vector （TLDV）. The hard core of this routing method is the identifier/locator split by the Distributed Hash Table （DHT） method, which provides a scalable routing service. The node locator indicates its relative location in the network and should be updated whenever topology changes, kocator space ks organized as a tree-structure, and the basic routing operation of the TLDV protocol is presented. TLDV protocol is compared to some classical routing protocols for MANETs on the NS2 platform Results show that TLDV has better scalability. Key words：
基金Supported by the National Natural Science Foundation of China (No. 60875055)Natural Science Foundation of Tianjin (No. 07JCY-BJC05400)Program for New Century Excellent Talents in University (No. NCET-06-0210)
文摘A practical serf-localization scheme for mobile robots is proposed and implemented by utilizing sonar sensors. Specifically, the localization problem is solved by employing Monte Carlo method with a new mechanism proposed to calculate the samples＇ weights; the convergence and veracity of the sample set are guaranteed by the designed resampling and scattering process. The proposed serf-localization algorithm is fully implemented on a specific mobile robot system, and experimental results illustrate that it provides an efficient solution for the kidnapped problem.
基金National Natural Science Foundation of China(Nos.51475328,61372143,61671321)
文摘Mobile robot navigation in unknown environment is an advanced research hotspot.Simultaneous localization and mapping(SLAM)is the key requirement for mobile robot to accomplish navigation.Recently,many researchers study SLAM by using laser scanners,sonar,camera,etc.This paper proposes a method that consists of a Kinect sensor along with a normal laptop to control a small mobile robot for collecting information and building a global map of an unknown environment on a remote workstation.The information(depth data)is communicated wirelessly.Gmapping(a highly efficient Rao-Blackwellized particle filer to learn grid maps from laser range data)parameters have been optimized to improve the accuracy of the map generation and the laser scan.Experiment is performed on Turtlebot to verify the effectiveness of the proposed method.
基金supported by the MKE(The Ministry of Knowledge Economy),Koreathe ITRC(Information Technology Research Center)support program(NIPA-2010-C1090-1021-0010)
文摘Using sensor and GPS to make a trajectory planning for the stationary obstacle, autonommus mobile robot can asstmae that it is placed at the center of the map, and from the distance information between autonomous mobile robot and obstacles. But in case of active moving obstacle, many components and information need to process since their moving trace should be considered in real time. This paper mobile robot＇s driving algorithm of unknown dynamic envirormaent in order to drive intelligently to destination using ultrasonic and Global Positional Systern （GPS）. Sensors adjusted the placement dependment on driving of robot, and the robot plans the evasion method according to obstacle which are detected by sensors. The robot saves GPS coordinate of complex obstacle. If there are many repeated driving, robot creates new obstacles to the hr, ation by itself. And then it drives to the destination resolving a large range of local minirmnn point If it needs an intelligent circtmtantial decision, a proposed algorithm is suited for effective obstacle avoidance and arrival at the destination by performing simulations.
文摘The autonomous navigation of an electric vehicle requires the implementation of a number of sensors and actuators intended to inform it about his environment or his position and velocity and deliver necessary inputs. That＇s why it is important to detect and locate sensor and actuator faults as soon as possible to enable the operator to run the vehicle in degraded mode or use the fault tolerant control system if it exists. The main purpose of this paper deals with sensors or actuators faults diagnosis of autonomous vehicle. A diagnosis method using a nonlinear model of the vehicle is developed. Nonlinear state space model of the autonomous electric vehicle is used with the method of nonlinear analytical redundancy to detect and to isolate faults occurred on sensors or actuators. Computer simulations are carried out to verify the effectiveness of the method.
基金supported by the MKE(The Ministry of Knowledge Economy,Korea)the ITRC(Information Technology Research Center)support program(ⅡTA-2009-(C1090-0902-0007))
文摘An accurate low-cost ultrasonic localization system is de- veloped for automated mobile robots in indoor environments, which is essential for automatic navigation of mobile robots with various tasks. Although ultrasenic sensors are more cost-effective than other sensors such as Laser Range Finder （LRF） and vision, but they are inaccurate and directionally ambiguons. First, the matched filter is used to measure the distance accurately. For resolving the computational complexity of the matched filter, a new matched filter algorithm with simple compution is proposed. Then, an ultrasonic localization system is proposed which consists of three ultrasonic receivers and two or mote transmitters for improving position and orientation accuracy was developed. Finally, an extended Kalman filter is designed to estimate both the static and dynamic positions and orientations. Various simu lations and experimental results show that the proposed system is effective.
文摘Severe sex ratio imbalance at birth is now becoming an important issue in several Asian countries. Its leading immediate cause is prenatal sex-selective abortion following illegal sex identification by ultrasound scanning. In this paper, a fast automatic recognition and location algorithm for fetal genital organs is proposed as an effective method to help prevent ultrasound technicians from unethically and illegally identifying the sex of the fetus. This automatic recognition algorithm can be divided into two stages. In the 'rough' stage, a few pixels in the image, which are likely to represent the genital organs, are automatically chosen as points of interest (POIs) according to certain salient characteristics of fetal genital organs. In the 'fine' stage, a specifically supervised learning framework, which fuses an effective feature data preprocessing mechanism into the multiple classifier architecture, is applied to every POI. The basic classifiers in the framework are selected from three widely used classifiers: radial basis function network, backpropagation network, and support vector machine. The classification results of all the POIs are then synthesized to determine whether the fetal genital organ is present in the image, and to locate the genital organ within the positive image. Experiments were designed and carried out based on an image dataset comprising 658 positive images (images with fetal genital organs) and 500 negative images (images without fetal genital organs). The experimental results showed true positive (TP) and true negative (TN) results from 80.5% (265 from 329) and 83.0% (415 from 500) of samples, respectively. The average computation time was 453 ms per image.
