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Modern programming of industrial robots is often based on the teach-repeat paradigm: a human operator places the robot in many key positions, for teaching its task. Then the robot can repeat a path defined by these key positions. This paper proposes a vision-based approach for the automation of the teach stage. The approach relies on a constant auto-calibration of the system. Therefore, the only requirement...
This paper reports on a study to develop power supplies for small mobile robots performing long duration missions. It investigates the use of fuel cells to achieve this objective, and in particular Proton Exchange Membrane (PEM) fuel cells. It is shown through a representative case study that, in theory, fuel cell based power supplies will provide much longer range than the best current rechargeable...
Collision-free navigation in cluttered environments is essential for any mobile manipulation system. Traditional navigation systems have relied on a 2D grid map projected from a 3D representation for efficiency. This approach, however, prevents navigation close to objects in situations where projected 3D configurations are in collision within the 2D grid map even if actually no collision occurs in...
The paper presents a velocity hysteresis friction model. This model can be used for simulation or control of an accurate micropositioning servomechanism. The mechanical and friction parameters are identified from measured signals at low velocities, and with the use of a closed loop identification method. The measured signals are very noised. The number of measurement samples available is very low...
Planning motion for humanoid robots requires obeying simultaneous constraints on balance, collision-avoidance, and end-effector pose, among others. Several algorithms are able to generate configurations that satisfy these constraints given a good initial guess, i.e. a configuration which is already close to satisfying the constraints. However, when selecting goals for a planner a close initial guess...
A large number of studies have been reported on top-down influences of visual attention. However, less progress have been made in understanding and modeling its mechanisms in real-world tasks. In this paper, we propose an approach for learning spatial attention taking into account influences of physical actions on top-down attention. For this purpose, we focus on interactive visual environments (video...
In teleoperation studies, most researchers have been researching on the stability and telepresence. Few of them have studied the influence of the operational status of the teleoperator on the telerobotic systems. As a matter of fact, improper and incorrect operations of the teleoperator may decrease the teleoperation efficiency and even result in some serious safety problems even if the stability...
This paper extends the novel research for event localization and target-directed navigation using a deployed wireless sensor network (WSN) [4]. The goal is to have an autonomous mobile robot (AMR) navigate to a target-location by: (i) producing an artificial magnitude distribution within the WSN-covered region, and (ii) having the AMR use the pseudo-gradient from the interpolated distribution in its...
For the development of medical micro-robotics and robotic manipulation of catheter it is necessary to ensure tissue integrity. In-vitro evaluation of tissue manipulation can be achieved using photoelastic stress analysis and vasculature modeling with photoelastic materials. In this research we propose epoxy resin as photoelastic material for vasculature modeling as it has a larger photoelastic coefficient...
We introduce a new technique for coordinating teams of unmanned aerial vehicles (UAVs) when deployed to collect live aerial imagery of the scene of a disaster. We define this problem as one of task assignment where the UAVs dynamically coordinate over tasks representing the imagery collection requests. To measure the quality of the assignment of one or more UAVs to a task, we propose a novel utility...
We present an algorithm for the generation of optimal trajectories for teams of heterogeneous quadrotors in three-dimensional environments with obstacles. We formulate the problem using mixed-integer quadratic programs (MIQPs) where the integer constraints are used to enforce collision avoidance. The method allows for different sizes, capabilities, and varying dynamic effects between different quadrotors...
Unmanned aerial vehicles (UAVs) have a so-far untapped potential to operate at high speeds through cluttered environments. Many of these systems are limited by their adhoc reactive controllers using simple visual cues like optical flow. Here we consider the problem of formally verifying an output-feedback controller for an aircraft operating in an unknown environment. Using recent advances in sums-of-squares...
Robot vision became a field of increasing importance in micro aerial vehicle robotics with the availability of small and light hardware. While most approaches rely on external ground stations because of the need of high computational power, we will present a full autonomous setup using only on-board hardware. Our work is based on the continuous homography constraint to recover ego-motion from optical...
In this paper we investigate the effectiveness of SURF features for visual terrain classification for outdoor flying robots. A quadrocopter fitted with a single camera is flown over different terrains to take images of the ground below. Each image is divided into a grid and SURF features are calculated at grid intersections. A classifier is then used to learn to differentiate between different terrain...
This paper addresses the problem of coordinating a team of mobile autonomous sensor agents performing a cooperative mission while explicitly avoiding inter-agent collisions in a team negotiation process. Many multi-agent cooperative approaches disregard the potential hazards between agents, which are an important aspect to many systems and especially for airborne systems. In this work, team negotiation...
Although current humanoid controllers can rely on inverse kinematics or dynamics of the full humanoid system, powered prosthetic legs or assistive devices cannot, because they do not have access to the full states of the human system. This limitation creates the need for alternative control strategies. One strategy is to embed fundamental knowledge about legged dynamics and control in local feedback...
Disturbance rejection is one of the most important abilities required for biped walkers. In this study, we propose a method for dynamic programming of biped walking and apply it to a simple passive dynamic walker (PDW) on an irregular slope. The key of the proposed approach is to employ the transient dynamics of the walker just before approaching the falling state in the absence of any controlling...
In this paper, we propose a framework for generating coordinated periodic movements of robotic systems with external inputs. We developed an adaptive pattern generator model that is composed of a two-factor observation model with a style parameter and phase dynamics with a phase variable. The style parameter controls the spatial patterns of the generated trajectories, and the phase variable controls...
Inverse optimal control is the problem of computing a cost function that would have resulted in an observed sequence of decisions. The standard formulation of this problem assumes that decisions are optimal and tries to minimize the difference between what was observed and what would have been observed given a candidate cost function. We assume instead that decisions are only approximately optimal...
Robotic studies have suggested a contribution of limit-cycle oscillation of the neuro-mechanical periphery to human walking by demonstrating stable bipedal robotic gaits with minimal actuation and control. As behavioral evidence of limit-cycle oscillation in human walking, we recently reported entrainment of human gaits to mechanical perturbations. We observed synchronization of human walking with...
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