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ABSTRACT: In the low inductance and small-sized brushless DC motor, the conventional PWM driving method makes relatively large copper loss because of an unintended directional transition current caused by ordinary complementary switching in the halfbridge circuits. We implemented the experimental feedforward current control system based on the method proposed by us in which the bridge circuits are driven non-complementarily to improve the power efficiency based on the circuit analysis and measured an actual power consumption. In the experimental system, driving circuits and micro controller are existing products in which control software is replaced, without current pickup circuit. In this paper, we report on the detail of the implementation and results of experiments on the real small-sized motor. And also the discussions on the effectiveness of proposed method is given.
IECON 2010 - 36th Annual Conference on IEEE Industrial Electronics Society; 12/2010
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ABSTRACT: Effective detection of people is a basic requirement for robot coexistence in human environments. In our previous work [1] we proposed a method for people detection and position estimation using multiple layers of Laser Range Finders (LRF) in a mobile robot. We extend our work by introducing laser reflection intensity as a novel feature for people detection, achieving significant improvement of detection rates. In concrete, we propose a method for calibration of laser intensity data, a method for segment separation using laser intensity, and introduce two new intensity-based features for people detection: the variance of laser intensity and the variance of intensity differences. We present experimental results that confirm the effectiveness of our multi-layered detection method including laser intensity.
Intelligent Robots and Systems (IROS), 2010 IEEE/RSJ International Conference on; 11/2010
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ABSTRACT: Successful detection of people is a basic requirement for a robot to achieve symbiosis in people's daily life. Specifically, a mobile robot designed to follow people needs to keep track of people's position through time, for it defines the robot's position and trajectory.
RO-MAN, 2010 IEEE; 10/2010
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ABSTRACT: In this paper, we propose a novel human detecting system using several stationary and moving laser range finders (LRF). The occluded area where the stationary sensors cannot measure will be covered by the actively moving sensor. The occlusion is perceived by overlaying visible area of the stationary sensors. The moving sensor will move to the target position where the sensor can measure the occluded area. Finally, the measured information of all sensors will be merged for data fusion. The experimental results show the effectiveness of the system.
Intelligent Robots and Systems, 2009. IROS 2009. IEEE/RSJ International Conference on; 11/2009
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ABSTRACT: This paper presents an approach for vehicle 3D localization in outdoor woodland environments using a loosely coupled multisensor system. The vehicle 3D dead reckoning is computed using a wheel encoder and an IMU. Dead reckoning is corrected from three different sources: a) using a tilted lidar for road detection and computation of the vehicle position within the road which is then corrected towards a 2D road centerline map given in advance. b) DGPS 2D or 3D data as available. c) Under tree foliage DGPS blackouts commonly occur, specially when measuring height, therefore the use of a barometer for correcting height is proposed. An extended Kalman filter is used for sensor fusion and pose estimation. Finally, the estimated vehicle height is added to the 2D map obtaining a 3D road centerline map with width (measured by the tilted lidar). Thoroughly experimentation on real mountainous woodland paths show the usefulness and robustness of the proposed approach.
Intelligent Robots and Systems, 2009. IROS 2009. IEEE/RSJ International Conference on; 11/2009
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ABSTRACT: In this paper, we propose a solution for human identification and localization with a mobile robot problem that implements multi-sensor data fusion techniques. This solution is designed for an autonomous luggage cart. The system utilizes a new approach based on identifying the target human visually from an omni directional camera then localizing and tracking him using LRF. This approach is composed of "registration stage" and "identification and localization stage". The registration stage extracts all necessary information needed including patches from the clothes. The identification is made using a modified pattern-matching algorithm to fit to a real time application. The tracking is implemented using a positions history structure to keep record of all positions of surrounding objects and the identified human.We implemented the proposed approach in fixed configuration to test its effectiveness.
Robot and Human Interactive Communication, 2009. RO-MAN 2009. The 18th IEEE International Symposium on; 11/2009
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ABSTRACT: Our goal is to configure an automatic baggage-transportation system by an inverted pendulum robot and realize a navigation function in a real environment. The system consists of two cooperative subsystems: a balancing-and-traveling control subsystem and a navigation subsystem. Position errors of the inverted pendulum robot are often caused by a drift error in the gyro sensor and a change in the center of gravity by a loaded baggage when applying the linear state feedback control method for balancing and traveling. We have reduced the position errors for navigation by resetting the balance position occasionally while traveling with simple methods without an external observer or alternative sensors. In this paper, we state the method and show the experimental results of navigation in a real environment by the implemented robot system.
IEEE Transactions on Industrial Electronics 11/2009; · 5.16 Impact Factor
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ABSTRACT: In this paper, we describe our positioning system based ultra-compact Laser Range Finder (LRF) for mobile robot. The system consists of reflectors as landmark and a laser range finder (LRF) named ldquoPos-URGrdquo. The landmarks are randomly and sparsely placed in environment, and their position and posture are known. Pos-URG has map data which consists of pose information and relation information between each landmark, which are sorted in ascending order of distance value between each other landmarks. When the Pos-URG finds multiple number of landmarks, the set of landmarks in map which correspond the detected landmarks is searched. The searching is done using not only each landmark's position and posture but also relations between them. Then, Pos-URG's position and posture is calculated with coordinate transform from sensor coordinates to map coordinates. The most important characteristic of this proposed searching method is its low computational time and it enables the method to be implemented into low-cost and low-spec CPU which is assembled into Pos-URG.
Advanced Robotics, 2009. ICAR 2009. International Conference on; 07/2009
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ABSTRACT: We are developing robots for inspection of the under floor of houses. The developed robot system is reported in this paper. The mobile robot platform is based on a crawer type robot developed for rescue purposes. As sensors, a pan-tilt-zoom camera, top-view camera and SOKUIKI sensor are used. We constructed a test field and verified the performance of the robot.
Robotics and Automation, 2009. ICRA '09. IEEE International Conference on; 06/2009
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ABSTRACT: This work proposes a new method people detection and position estimation from a mobile robot by fusion of multiple laser range finders arranged in two layers. Sensors facing opposite directions in a single row (layer) are fused to produce 360deg scan data of robotpsilas surroundings, then data from every layer is further fused to create a 3D model of people and from there their position. The main problem of our research is an autonomous mobile robot acting as member of a people group moving in public areas, simple and accurate people detection and tracking is an important requirement. We present experimental results of fusion steps and people detection in an indoor environment.
Multisensor Fusion and Integration for Intelligent Systems, 2008. MFI 2008. IEEE International Conference on; 09/2008
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ABSTRACT: Time is crucial in applications such as sensor data fusion, autonomous mobility and SLAM. However clocks at end systems are rarely synchronized and often running at different speeds. Lack of synchronization therefore reduces the accuracy of sensor readings. The SOKUIKI scanning laser range finder allows acquiring time values by timestamping range readings. Our work consists in a method for time synchronization, with clock skew estimation, between a laser range finder sensor and a host computer.
Multisensor Fusion and Integration for Intelligent Systems, 2008. MFI 2008. IEEE International Conference on; 09/2008
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ABSTRACT: Our goal is to configure a baggage transportation system by an inverted pendulum robot and realize a navigation system. The system is consisted from two sub-systems, one is balancing-and-running control system, and the other is the navigation system, and they work with each other. In this paper, we state those systems and show some experiments for that.
Advanced Motion Control, 2008. AMC '08. 10th IEEE International Workshop on; 04/2008
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ABSTRACT: This paper describes a system which uses a mobile manipulator as a teleoperated tool for accessing and manipulating remote objects. This system attempts to answer the challenge of extending mobile robot potentials and usage in human daily life. The specific task we set up in this research is to help people buy fresh food in a supermarket from a remote location using the Internet. We built the prototype system by integrating custom designed components: the mobile manipulator, the sucker gripper, the shape scanner using a small laser range finder, and the communication interface. With this system, the selection of the food item by the remote user from the supermarket showcase, its close examination using the gripper, and final placement into the shopping basket were realized. This paper describes the hardware and software of this system, and shows the experimental result performed with the integrated system.
Mechatronics and Automation, 2007. ICMA 2007. International Conference on; 09/2007
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ABSTRACT: Recently, tracking and counting people are requested for the security purpose. In this paper, we propose a method to track and count people with laser range finders. A method to extract the walking human from the sensor data is introduced. Multi-target model and Kalman filter based estimation are employed to track the human movement and count the number of people. The proposed method is applied to a novel system to monitor the entrance area and to filter out the trespasser who enters the door without identification. Experiments for various cases are performed to verify the usefulness of developed proto-type system.
Mechatronics and Automation, 2007. ICMA 2007. International Conference on; 09/2007
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ABSTRACT: The purpose of this research is to develop a system which gives blind people information of the environment around them. A person is equipped with a 3D scanner and a small sized PC while walking. The scanner scans and acquires 3D range data map of the environment. The PC analyzes the range data map and detects objects which are useful for blind people in order to walk. The PC gives environmental information to them by synthesized sound. This paper first introduces the concept of the whole system and clarify the tasks for realizing the system. Secondly the method for acquisition of 3D range data and detecting objects and obstacles are described. Then the usefulness of our proposed system is examined by an experiment in which our trial system detects bumps and trenches in the experimental environment
IEEE Industrial Electronics, IECON 2006 - 32nd Annual Conference on; 12/2006
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ABSTRACT: The purpose of this research is to develop a robot system which helps humans to remotely accomplish a daily given task such as shopping. This teleoperated system is based on simple mutual human-robot cooperation where the person remotely communicates with the mobile robot. We define the specific task of buying FRESH foods in a supermarket from a remote location. In order to do shopping operations, the robot has to be able of grasping a large amount of objects with different textures, shapes and weights which include fruits and vegetables with soft and irregular forms. After the user chooses the product to buy, the process is the next, firstly the robot has to find the object, then grasp it and then place it into a shopping basket. In this work, we built a system according to the previously explained requirements which involves autonomous navigation, environment perception, object manipulation and teleoperation. In this paper, we present the developed suction hand for picking fresh foods and evaluate its operating performance through experimental results
Intelligent Robots and Systems, 2006 IEEE/RSJ International Conference on; 11/2006
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ABSTRACT: This paper describes a grasp planning for a mobile manipulator which works in real environment. Mobile robot studies up to now that manipulate an object in real world practically use ID tag on an object or an object model which is given to the robot in advance. The authors aim to develop a mobile manipulator that can acquire an object model through video images and can manipulate the object. In this approach, the robot can manipulate an unknown object autonomously. A grasp planning proposed in this paper can find a stable grasp pose from the automatically generated model which contains redundant data and the shape error of the object. Experiments show the effectiveness of the proposed method
Robotics and Automation, 2006. ICRA 2006. Proceedings 2006 IEEE International Conference on; 06/2006
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ABSTRACT: Despite that omni-directional mobile robots have been investigated and used popularly, there are rarely useful command systems and control methods for practical applications. In this research, a command system to describe the navigation task for an omni-directional mobile robot is developed, and a motion generation method considering the robot geometry and the given trajectory is proposed. Furthermore, a control method to track the given linear and circular trajectories is proposed. A closed form kinematic model was utilized for motion generation and control as well. A redundantly actuated omni-directional mobile robot that consists of three caster-type wheel mechanisms with high performance embedded controller module was developed for the experiments. And some experiments in the real environment were carried out to verify the effectiveness of the proposed command system and the performance of the motion generation and the trajectory control method.
Intelligent Robots and Systems, 2005. (IROS 2005). 2005 IEEE/RSJ International Conference on; 09/2005
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ABSTRACT: We have developed a 2D laser range sensor suitable for mobile robot platforms. The sensor features compactness, lightweight, high precision and low power consumption, and provides the wide scan angle with high resolution, which is very important for environment recognition by mobile robots. The basic technology for measuring the distance between the sensor and objects are; using amplitude modulation of light waves and detecting the phase difference between transmitted and the received one. This paper explains the specification of the proto-type sensor, the method of distance measurement and examples of experimental results.
Intelligent Robots and Systems, 2005. (IROS 2005). 2005 IEEE/RSJ International Conference on; 09/2005
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ABSTRACT: In this paper a multirobot system (MRS) trajectory control for conducting a group of humans is proposed. Its architecture, implementation and the strategy to conduct people by a team of robots is discussed, as well as the robots motion planning methodology is being encompassed. Some experimental results on people localization by a vision system are also introduced, which exhibit its usage as sensory information for generation of people trajectory control. A social model to simulate humans motion is also included in this investigation as means to prove the mechanism of guidance and crowd dynamics by the team of robots, where such motion control is based on intelligent changes of position and speed
Advanced Robotics, 2005. ICAR '05. Proceedings., 12th International Conference on; 08/2005
