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Takens' Embedding Theorem asserts that when the states of a hidden dynamical system are confined to a low-dimensional attractor, complete information about the states can be preserved in the observed time-series output through the delay coordinate map. However, the conditions for the theorem to hold ignore the effects of noise and time-series analysis in practice requires a careful empirical determination...
In this paper, a multi-variable nonlinear control of a twin rotor aerodynamical system (TRAS) is presented. A control-oriented state-space model with four states is derived employing Lagrange's equations. Using this system representation, a multi-variable flatness-based control is designed for an accurate trajectory tracking concerning both the pitch angle characterising the vertical motion and the...
This paper deals with motion control of the inertia wheel pendulum. Specifically, we address a trajectory tracking problem. The proposed control algorithm is derived from feedback linearization, with the output of the system defined as the tracking error between a desired reference trajectory and the angular position of the inverted pendulum. The explicit expressions of the internal dynamics and zero-dynamics...
Human action recognition from video input has seen much interest over the last decade. In recent years, the trend is clearly towards action recognition in real-world, unconstrained conditions (i.e. not acted) with an ever growing number of action classes. Much of the work so far has used single frames or sequences of frames where each frame was treated individually. This paper investigates the contribution...
This article presents a new method for crowd behavior recognition, using dynamic features extracted from dense trajectories. The histogram of oriented gradient and motion boundary histogram descriptors are computed at dense points along motion trajectories, and tracked using median filtering and displacement information obtained from a dense optical flow field. Then a global representation of the...
Whole-body controllers provide the tools to execute multiple simultaneous tasks on humanoid robots, but given the robot's internal and external constraints, interferences are often generated which impede task completion. Priorities can be assigned to each task to manage these interferences, unfortunately, this is often done at the detriment of one or more tasks. In this paper we present a novel framework...
Permanent magnet synchronous motor (PMSM) are favored in traction drives of rail vehicles for their high efficiency of operation. Traction inverters always operate at reduced switching frequency to minimize the losses in semiconductor devices. To restrain the motor current harmonics, off-lined calculated optimal synchronous pulse patterns can be used. This paper presents a closed-loop control of permanent...
This paper addresses attitude estimation for UUVs(Unmanned Underwater Vehicles) using low-cost MEMS(Microelectromechanical Systems) AHRS(Attitude Heading Reference System). It compares extended Kaiman filter, unscented Kaiman filter, and complementary filter method used for attitude estimation. The experiment uses the estimated attitude for localization of a UUV(Unmanned Underwater Vehicle) based...
A trajectory specification method for a flapping-wing flying robot exhibiting a novel dynamical model than other types of micro aerial vehicles such as quadrotors and airplanes is presented. The desired trajectory is first defined as a vector-valued, differentiable parametric curve of the form f : RR → RR. The velocity vector at any point of the trajectory is the same as the unit tangent vector obtained...
In recent years, various robot hands and arms have been developed for achieving dexterous manipulation tasks. However, there are few robots that are able not only to move quickly but also to handle tools dexterously. Motion in the Japanese game kendama is one example of dynamic manipulation and skillful handling. Although robotic kendma has been studied in the past, these robotic hands cannot be used...
Humans as well as humanoid robots can use a large number of degrees of freedom to solve very complex motor tasks. The high-dimensionality of these motor tasks adds difficulties to the control problem and machine learning algorithms. However, it is well known that the intrinsic dimensionality of many human movements is small in comparison to the number of employed DoFs, and hence, the movements can...
The advent of humanoids has brought new challenges in the real-world application. As a part of ongoing efforts to foster functionality of the robot accommodating a real environment, this paper introduces a recent progress on a door opening task with our compliant humanoid, CoMan. We presents a task-prioritized impedance control framework for an upper body system that includes a dual-arm, a waist,...
Autonomous manipulation in dynamic environments is important for robots to perform everyday tasks. For this, a manipulator should be capable of interpreting the environment and planning an appropriate movement. At least, two possible approaches exist for this in literature. Usually, a planning system is used to generate a complex movement plan that satisfies all constraints. Alternatively, a simple...
This paper proposes a probabilistic framework based on movement primitives for robots that work in collaboration with a human coworker. Since the human coworker can execute a variety of unforeseen tasks a requirement of our system is that the robot assistant must be able to adapt and learn new skills on-demand, without the need of an expert programmer. Thus, this paper leverages on the framework of...
Robotic learning on real hardware requires an efficient algorithm which minimizes the number of trials needed to learn an optimal policy. Prolonged use of hardware causes wear and tear on the system and demands more attention from an operator. To this end, we present a novel black-box optimization algorithm, Reward Optimization with Compact Kernels and fast natural gradient regression (ROCK∗). Our...
In this work, a fuel cell hybrid electric source is presented. The energy management among different components is assured by applying a control algorithm based on the nonlinear flatness principle. The studied hybrid sources use fuel cells (polymer electrolyte membrane technology) and lithium-ion batteries as main and auxiliary sources. The goal is to supply domestic load (a house), maintain the DC...
This paper presents a control principle for a hybrid wind turbine-Fuel cell and supercapacitor system. Several techniques of control necessitate a linear mathematical model in order to get an inverse dynamic solution. However, in more complex systems the linearization is not sufficient to solve the problem. Therefore, a flatness control has been used in this study, which permits the entire description...
With the emergence of unmanned aerial vehicles in recent time, the research on trajectory and path following control methodologies became increasingly popular due to various applications for these test platforms. In this context, this paper presents a trajectory / path following controller, which is derived based on nonlinear dynamic inversion of nonlinear error dynamics between a specified trajectory...
Dynamic movement is needed for challenging robots which play soccer for obtaining an effective trajectory for individual robot. In this paper, we use exactly 2 agent robots which can be moved using autonomous holonomic movement. Based on visualization, the position of multi-agent robot soccer is localized by image processing from color marker on each of them, It means that their coordinate marker...
In order to successfully navigate mobile robots in an unknown environment, an appropriate navigation strategy must be employed. Such a strategy certainly relies on an effective navigation map based on which robot trajectories can be well planned. The navigation map can be built based on a sparse map constructed by a visual simultaneous localization and mapping (VSLAM) algorithm. This paper presents...
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