Unlike conventional haptic devices, an encountered-type device is not held by a user all the time. Instead, the device remains at the location of a virtual object and waits for the user to encounter it. In this paper,...
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ISBN:
(纸本)3540232141
Unlike conventional haptic devices, an encountered-type device is not held by a user all the time. Instead, the device remains at the location of a virtual object and waits for the user to encounter it. In this paper, we extend this concept to fingertip contacts and design an encountered-type haptic display for multiple fingertip contacts to simulate tasks of grasping an object with any shape and size. Before designing the device, we intensively observed human grasping behaviors. This observation was very helpful to determine the mechanism of the device. An encountered-type device for three-fingered grasping was actually prototyped based on our design.
In this paper we address the problem of planning reliable landmark based robot navigation strategies in the presence of significant sensor uncertainty. The navigation environments are modeled with directed weighted gr...
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ISBN:
(纸本)3540404767
In this paper we address the problem of planning reliable landmark based robot navigation strategies in the presence of significant sensor uncertainty. The navigation environments are modeled with directed weighted graphs in which edges can be traversed with given probabilities. To construct robust and efficient navigation plans, we compute "expected shortest paths " in such graphs. We formulate the expected shortest paths problem as a Markov decision process and provide two algorithms for its solution. We demonstrate the practicality of our approach using an extensive experimental analysis using graphs with varying sizes and parameters.
In this paper we present an approach to estimating the contact state between a robot and its environment during task execution. Contact states are modeled by constraint equations parametrized by time-dependent sensor ...
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ISBN:
(纸本)3540003053
In this paper we present an approach to estimating the contact state between a robot and its environment during task execution. Contact states are modeled by constraint equations parametrized by time-dependent sensor data and time-independent object properties. At each sampling time, multiple model estimation is used to assess the most likely contact state. The assessment is performed by a hidden Markov model, which combines a measure of how well each set of constraint equations fits the sensor data with the probability, of specific contact state transitions. The latter is embodied in a task-based contact state network. The approach is illustrated for a three-dimensional peg-in-hole insertion using a tabletop manipulator robot. Using only position sensing, the contact state sequence is successfully estimated without knowledge of nominal property values. Property estimates are obtained for the peg dimensions as well as the hole position and orientation.
The International Rescue System Institute has been established in Japan to promote research and development of key technologies for the realization of practical search-and-rescue robots, anticipating future large-scal...
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ISBN:
(纸本)3540003053
The International Rescue System Institute has been established in Japan to promote research and development of key technologies for the realization of practical search-and-rescue robots, anticipating future large-scale earthquakes and other catastrophic disasters. In this paper we propose a new paradigm called "snakes and strings", for developing practical mobile robot systems that may be useful in such situations. "Snakes" stands for snake-like robots, which can skillfully move among the debris of the collapsed buildings. "Strings", on the other hand, means robotic systems using strings or tethers, such as proposed in the "hyper-tether" research. Tethers can continuously supply energy, accomplish reliable communication links, and also exhibit high traction force. In this paper we present many new mechanical implementations of snake-like robots developed in our laboratory, and we also explain in detail the new paradigm.
In this paper we briefly address DLR's (German Aerospace Center) background in space robotics by hand of corresponding milestone projects including systems on the International Space Station. We then discuss the k...
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ISBN:
(纸本)3540003053
In this paper we briefly address DLR's (German Aerospace Center) background in space robotics by hand of corresponding milestone projects including systems on the International Space Station. We then discuss the key technologies needed,for the development of an artificial "robonaut" generation with mechatronic ultra-lightweight arms and multifingered hands. The third arm generation is nearly finished now, approaching the limits of what is technologically achievable today with respect to light weight and power losses. In a similar way DLR's second generation of artificial four-fingered hands was a big step towards higher reliability, manipulability and overall performance.
One of the more startling effects of road related accidents is the economic and social burden that they cause. In OECD countries (the 23 leading economically, developed countries of the world) over 150,000 people are ...
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ISBN:
(纸本)3540003053
One of the more startling effects of road related accidents is the economic and social burden that they cause. In OECD countries (the 23 leading economically, developed countries of the world) over 150,000 people are killed every year (44,000+ in the USA, 38,000+ in Europe and 11,000+ in Japan) at an estimated cost of US$ 500 billion. One way of combating this problem is to develop intelligent vehicles that are self-aware and act to increase the safety of the transportation system. In this paper we present preliminary results of an Intelligent Transport System project that has fused visual lane tracking and driver monitoring technologies in the first step towards closing the loop between vision inside and outside the vehicle. Experimental results of a novel 15 Hz visual lane tracking system will be discussed, focusing on the particle filter and cue fusion technology used. The results from the integration of the lane tracker and the driver monitoring system are presented with an analysis of the driver's visual behavior in several different scenarios.
In recent years, many successful robotic manipulator designs have been introduced. However there remains the challenge of designing a manipulator that possesses the inherent safety characteristics necessary for human-...
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ISBN:
(纸本)3540003053
In recent years, many successful robotic manipulator designs have been introduced. However there remains the challenge of designing a manipulator that possesses the inherent safety characteristics necessary for human-centered robotics. In this paper we present a new actuation approach that has the requisite characteristics for inherent safety while maintaining the performance expected of modern designs. By drastically reducing the effective impedance of the manipulator while maintaining high-frequency torque capability, we show that the competing design requirements of performance and safety can be successfully integrated into a single manipulation system.
The Modular Distributed Manipulator System (MDMS) is an array of actuators that is capable of manipulating objects in the plane. This paper presents a controller designed to transport objects to the origin of a coordi...
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ISBN:
(纸本)3540404767
The Modular Distributed Manipulator System (MDMS) is an array of actuators that is capable of manipulating objects in the plane. This paper presents a controller designed to transport objects to the origin of a coordinate system under rolling contact. A stability proof using the multivariable circle criterion directly accounts for discontinuities due to changing actuator sets. Simulations verify the controller's effectiveness and show stability even when the contact switches between viscous friction and full rolling contact.
We introduced the concept of C-space entropy recently in [1-3] as a measure of knowledge of C-space for sensor-based path planning and exploration for general robot-sensor systems. The robot plans the next sensing act...
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ISBN:
(纸本)3540404767
We introduced the concept of C-space entropy recently in [1-3] as a measure of knowledge of C-space for sensor-based path planning and exploration for general robot-sensor systems. The robot plans the next sensing action to maximally reduce the expected C-space entropy, also called the maximal expected entropy reduction, or MER criterion. The expected C-space entropy computation, however, made two idealized assumptions. The first was that the sensor field of view (FOV) is a point;and the second was that no occlusion (or visibility) constraints are taken into account, i.e., as if the obstacles are transparent. We extend the expected C-space entropy formulation where these two assumptions are relaxed, and consider a generic range sensor with non-zero volume FOV and occlusion constraints, thereby modelling a real range sensor. Planar simulations show that (i) MER criterion results in significantly more efficient exploration than the naive physical space based criterion (such as maximize the unknown physical space volume), (ii) the new formulation with non-zero volume FOV results in further improvement over the point FOV based MER formulation.
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