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In this paper, a novel gait assessment system based on measures of gait variability reflected through the variability of shapes of gait cycles trajectories is proposed. The presented gait assessment system is based on SVM (support vector machine) classifier and on gait variability-based features calculated from the hip and knee joint angle trajectories recorded using wearable IMUs during walking trials...
Augmented feedback has been shown to improve interaction in virtual environments and to facilitate motor learning. Recent studies proposed this type of feedback to guide users, to highlight specific areas or to help them to perform a specific task. They can follow a path, pass through specific waypoints or even mimic an avatar. However these approaches do not show the gap between learners' performance...
Human bodies and movements exhibit inherent symmetry. However, an important class of everyday movements, such as walking, does not maintain symmetry at every time instance. The symmetry in these movements is a spatiotemporal glide-reflection symmetry. The ability to measure this type of symmetry will provide us opportunities for various computer-aided applications including health monitoring, rehabilitation,...
This paper deals with a performance analysis and optimal tuning of an intelligent proportional (iP) controller for the first order time delayed plants. iP control represents the simplest solution used within the so called “model free control”. Although it has been primarily developed for more complex nonlinear plants, its basic performance analysis may preferably be carried out in a simple linear...
The location of the center of mass of failed or abandoned satellites is a fundamental information for a safe capturing with servicing or removing purposes. The complete observation of the satellite dynamics relative to a chaser spacecraft is often pursued by feeding Kalman filters with positions of a fixed set of features of the target. The difficulties in tracking with continuity this set pose serious...
In this work, we propose a novel implementation of the Probability Density Hypotheses (PHD) filter for tracking an unknown number of extended objects. For this purpose, we first show how a recently developed Kalman filter-based method for elliptic shape tracking can be embedded into the Gaussian Mixture PHD (GM-PHD) filter framework. Second, we propose a track labeling method based on a Minimum-Cost...
This paper discusses the possibility of using the geometric shape of a pedestrian's head to shoulder region as a feature to identify individuals. The main aim is to track humans in a high density crowd using a 3D laser range finder (3D-LRF). One of the most critical problems of human tracking in a high density crowd is the occurrence of occlusion. Occlusion might occur because of the lack of features...
Humans can accurately distinguish the shape of objects through haptic interaction. In the present study, we investigated the haptic perception of the size of large pliers held with both hands. An haptic size discrimination task was conducted in three experimental conditions: (1) a free bimanual condition where the pliers were free to move in the fronto-parallel plane; (2) a bimanual constrained condition...
Sparse representation is widely used by different human activity recognition methods. Although many sparse feature extraction algorithms have been proposed in the literature, most of them focused on low-level features. This paper proposes a new method using trajectories, as mid-level features, for human activity recognition. Even though the use of trajectories is not new in this field, their potential...
In the paper discussed results of investigation of increasing of shape passableness and adaptability to terrain for walking machines and robots with cyclic movers types. Usage of cyclic walking movers allows not to care about gait safety and stability and exclude the necessity in controlled adaptation system. By the other hand, strict trajectory of support points of cyclic type of walking mechanisms...
In this paper, a new approach for 3D skeleton-based human motion recognition is discussed. First, we opted to represent the movement as a set of body joints trajectories. Those trajectories are then converted into ropes histograms. The motion records are obtained using the Kinect motion sensor. The classification phase consists in comparing those histograms with ropes histograms of a set of reference...
Human action recognition is currently a hot topic research domain including a variety of applications such as human HMI, rehabilitation and surveillance. The majority of existing approaches are based on the skeleton. They utilize either the joint locations or the joint angles in order to present a human skeleton. This study introduce a novel framework, which allows compact representation, quick comparison...
Identification of intended movement type and movement phase of hand grasp shaping are critical features for the control of volitional neuroprosthetics. We demonstrate that neural dynamics during visually-guided imagined grasp shaping can encode intended movement. We apply Procrustes analysis and LASSO regression to achieve 72% accuracy (chance = 25%) in distinguishing between visually-guided imagined...
In this work, multiple robots circulate around the boundary of a desired region in order to create a virtual fence. The aim of the this fence is to avoid internal or external agents crossing through the delimited area. In this paper, we propose a distributed technique that allows a team of robots to plan the deformation of the boundary shape in order to escort the safe region from one place to a goal...
Formation tracking and transformation are the key problems in formation control of multi-AUV (autonomous underwater vehicle) system. In this paper, an improved self-organizing map (SOM) neural network method is proposed for solving the formation issues of a group of autonomous underwater vehicles (AUVs). All the AUVs in the formation are treated equal to be the leaders or the followers. The desired...
Humanlike robot skills, e.g., cleaning a table or handing over a plate, can often be generalized to different task variations. Usually, these are start-/goal position, and trained environment changes. We investigate how to modify motion primitives to context changes, which are not included in the training data. Specifically, we focus on maintaining humanlike motion characteristics and generalizability,...
In this work, we propose a method to compute the stiffness of flexible joints and its realization in order to let the fingers track a certain predefined trajectory. We refer to tendon-driven, underactuated and passively compliant hands composed of deformable joints and rigid links. Specific stiffness and pre-form shapes can be assigned to the finger joints can be given s such that a single-cable actuation...
Safety Barrier Certificates that ensure collision-free maneuvers for teams of differential flatness-based quadrotors are presented in this paper. Synthesized with control barrier functions, the certificates are used to modify the nominal trajectory in a minimally invasive way to avoid collisions. The proposed collision avoidance strategy complements existing flight control and planning algorithms...
This paper proposes a nonprehensile manipulation scheme using the vibration of a plate, where a 3-DoF (degree of freedom) motion of a part is controlled using a single actuator. A manipulator is introduced, the end effector of which is a flat plate. The manipulator employs a hybrid joint mechanism with a twisted axis layout. The characteristic of this mechanism is that the shape of the trajectory...
For a manipulation skill to be applicable to a wide range of scenarios, it must generalize between different objects and object configurations. Robots should therefore learn skills that adapt to features describing the objects being manipulated. Most of these object features will however be irrelevant for generalizing the skill and, hence, the robot should select a small set of relevant features for...
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