This paper discusses the Stiffness Imager that can provide us with the pattern of stiffness (or pseudo-stiffness) distribution of environment. While there are four combinations between force applying method and the wa...
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ISBN:
(纸本)3540288163
This paper discusses the Stiffness Imager that can provide us with the pattern of stiffness (or pseudo-stiffness) distribution of environment. While there are four combinations between force applying method and the way for measuring the displacement, we pick up the combination in which the force is given to the environment at a local point and the displacement of environment is measured over the neighboring area where the force is given. We apply the idea to an endoscope camera, so that we can obtain not only visual information but also the pseudo-stiffness pattern. We also show a couple of experimental results exhibiting the pseudo-stiffness pattern.
For several years, our research group has been developing methods for automated modeling of 3D environments. In September, 2002, we were given the opportunity to demonstrate our mapping capability in an underground co...
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ISBN:
(纸本)3540328017
For several years, our research group has been developing methods for automated modeling of 3D environments. In September, 2002, we were given the opportunity to demonstrate our mapping capability in an underground coal mine. The opportunity arose as a result of the Quecreek mine accident, in which an inaccurate map caused miners to breach an abandoned, water-filled mine, trapping them for several days. Our field test illustrates the feasibility and potential of high resolution three-dimensional (3D) mapping of an underground coal mine using a cart-mounted 3D laser scanner. This paper presents our experimental setup, the automatic 3D modeling method used, and the results of the field test. In addition, we address issues related to laser sensing in a coal mine environment.
A virtual fence is created by applying an aversive stimulus to an animal when it approaches a predefined boundary. It is implemented by a small animal-borne computer system with a GPS receiver. This approach allows th...
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ISBN:
(纸本)3540288163
A virtual fence is created by applying an aversive stimulus to an animal when it approaches a predefined boundary. It is implemented by a small animal-borne computer system with a GPS receiver. This approach allows the implementation of virtual paddocks inside a normal physically-fenced paddock. Since the fence lines are virtual they can be moved by programming to meet the needs of animal or land management. This approach enables us to consider animals as agents with natural mobility that are controllable and to apply a vast body of theory in motion planning. In this paper we describe a herd-animal simulator and physical experiments conducted on a small herd of 10 animals using a Smart Collar. The Smart Collar consists of a GPS, PDA, wireless networking and a sound amplifier. We describe a motion planning algorithm that can move a virtual paddock subject to landscape constraints which is suitable for mustering cows. We present simulation results and data from experiments with 8 cows equipped with Smart Collars.
Applying low-cost sensors for the Guidance, Navigation and Control (GNC) of an autonomous Uninhibited Aerial Vehicle (UAV) is an extremely challenging area. This paper presents the real-time results of applying a low-...
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ISBN:
(纸本)3540328017
Applying low-cost sensors for the Guidance, Navigation and Control (GNC) of an autonomous Uninhibited Aerial Vehicle (UAV) is an extremely challenging area. This paper presents the real-time results of applying a low-cost Inertial Measurement Unit (IMU) and Global Positioning System (GPS) receiver for the GNC. The INS/GPS navigation loop provides continuous and reliable navigation solutions to the guidance and flight control loop for autonomous flight. With additional air data and engine thrust data, the guidance loop computes the guidance demands to follow way-point scenarios. The flight control loop generates actuator signals for the control surfaces and thrust vector. The whole GNC algorithm was implemented within an embedded flight control computer. The real-time flight test results show that the vehicle can perform the autonomous flight reliably even under high maneuvering scenarios.
This work is devoted to planning and execution of complex missions in robotics. robotics has evolved from an industrial, repetitive framework to application domains with much more variability of tasks, with increasing...
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ISBN:
(纸本)3540288163
This work is devoted to planning and execution of complex missions in robotics. robotics has evolved from an industrial, repetitive framework to application domains with much more variability of tasks, with increasing complexity in uncertain environment. This is clearly the case for Service robotics e.g. but even industrial robots have now to work in environment not totally calibrated for the task they have to perform. The result is that the classical decomposition in static ordered local tasks cannot apply in presence of such a variability. It has a poor dynamic performance and cannot cope with uncertainties. Our work is organized around a complex mission: "Go to the blackboard and write" for mobile manipulators that have capabilities of locomotion and manipulation. It is a simple and intuitive example of a complex mission that relies on different sensors, exhibits different operating modes and needs to switch between different feedbacks and set-points. Our approach is based on Hybrid Dynamical Systems. It is focused on dynamical sequencing of control laws that ensures good transients, robustness and allows to update the mission at every transition from one mode to another. Simulation have been realized with matlab Simulink and Stateflow toolboxes and experimental validation is developed within the G(en) om controller on the h(2)bis nonholonomic mobile manipulator.
An approach to motion planning among moving obstacles is presented, whereby obstacles are modeled as intelligent decision-making agents. The decision-making processes of the obstacles are assumed to be similar to that...
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ISBN:
(纸本)3540328017
An approach to motion planning among moving obstacles is presented, whereby obstacles are modeled as intelligent decision-making agents. The decision-making processes of the obstacles are assumed to be similar to that of the mobile robot. A probabilistic extension to the velocity obstacle approach is used as a means for navigation as well as modeling uncertainty about the moving obstacles' decisions.
We develop a network of distributed mobile sensor systems as a solution to the emergency response problem. The mobile sensors are inside a building and they form a connected ad-hoc network. We discuss cooperative loca...
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ISBN:
(纸本)3540328017
We develop a network of distributed mobile sensor systems as a solution to the emergency response problem. The mobile sensors are inside a building and they form a connected ad-hoc network. We discuss cooperative localization algorithms for these nodes. The sensors collect temperature data and run a distributed algorithm to assemble a temperature gradient. The mobile nodes are controlled to navigate using this temperature gradient. We also discuss how such networks can assist human users to find an exit. We have conducted an experiment at a facility used to train firefighters in order to understand the environment and to test component technology. Results from experiments at this facility as well as simulations are presented here.
We describe a mobile robot system, designed to assist residents of an retirement facility. This system is being developed to respond to an aging population and a predicted shortage of nursing professionals. In this pa...
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ISBN:
(纸本)3540328017
We describe a mobile robot system, designed to assist residents of an retirement facility. This system is being developed to respond to an aging population and a predicted shortage of nursing professionals. In this paper, we discuss the task of finding and escorting people from place to place in the facility, a task containing uncertainty throughout the problem. Planning algorithms that model uncertainty well such as Partially Observable Markov Decision Processes (POMDPs) do not scale tractably to real world problems such as the health care domain. We demonstrate an algorithm for representing real world POMDP problems compactly, which allows us to find good policies in reasonable amounts of time. We show that our algorithm is able to find moving people in close to optimal time, where the optimal policy starts with knowledge of the person's location.
This paper presents analysis of traction mechanics and control of a lunar/planetary rover based on the models obtained from terramechanics. A case study has been conducted for a rover test bed to negotiate a slope of ...
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ISBN:
(纸本)3540328017
This paper presents analysis of traction mechanics and control of a lunar/planetary rover based on the models obtained from terramechanics. A case study has been conducted for a rover test bed to negotiate a slope of loose soil such as regolith that covers most of lunar surface. The tire traction force is modeled as a function of the vertical load and slip ratio of the wheel. Bekker's terramechanic formulae are employed to derive an improved practical model that calculates net traction force, referred to as Drawbar Pull, with a reasonable precision. Experiments are carried out in two phases. First, the physical behavior of a wheel on loose soil is observed using a single-wheel test bed, then the empirical parameters of the tire and soil are identified. Second, the slope climbing capability is studied by using a rover test bed that has independently driven four wheels. The traction margin and slip margin are defined to be used in a traction control. In the slope experiment, it turned out that the climbing capability was saturated at 14 degrees due to the lack of enough driving torque in wheels. But theoretical investigation suggests that this is not the limitation of terrain trafficability and climbing capability can be improved by increased driving torque and proper load distribution.
This paper proposes a discovery algorithm of knowledge of remarkable motion features in SVM-based action recognition. The main characteristics of the proposed method are a) basic scheme of the algorithm is based on Su...
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ISBN:
(数字)9783540330141
ISBN:
(纸本)3540288163
This paper proposes a discovery algorithm of knowledge of remarkable motion features in SVM-based action recognition. The main characteristics of the proposed method are a) basic scheme of the algorithm is based on Support Vector Learning and its generalization error, b) remarkabale motion features are discovered in response to kernel parameters optimization through generalization error minimization. Experimental results show that this proposed algorithm makes the recognition robust and finds remarkable motion features that are intuitive for human.
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