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Active contours or snakes are widely used for segmentation and tracking. Multiple object tracking remains a difficult task, characterised by a trade off between increasing the capturing range of edges of the object of interest, and decreasing the capturing range of other edges. We propose a new external force field which is calculated for every object independently. This new force field uses prior...
We present a design of an autopilot for a Bank-to-Turn asymmetric missile. The autopilot is synthesised using a method based on a linear parameter varying model of the missile, and because of significant cross-couplings in the different channels a multivariable design is considered. In the paper, attention is first focussed on the development of an LPV model of the missile. The choice of the scheduling...
This paper addresses the problem of steering a quadrotor vehicle along a time-dependent trajectory. The problem is formulated so as to take into account force disturbances acting on the vehicle and enforce bounds on the actuation. The proposed solution consists of a nonlinear adaptive state feedback controller for thrust and torque actuation that i) guarantees asymptotic stability of the closed-loop...
This paper deals with latching control of the SEAREV ocean wave energy converter. It has been shown in previous studies that latching control could improve considerably the overall efficiency of the system, but assuming that the actuators idealy apply forces instantaneously. In reality, time constants are unavoidable in the response of the actuators and this can have an influence on the global benefit...
Due to the presence of strong non-linearities (i.e. coulomb friction) some systems change their dynamic dimension while functioning. Such systems can be found in many application fields, such as in automotive and robotics. This paper proposes a simulation model for this type of systems that we will call as "Variable Dynamic Dimension Systems" (VDDS). Particularly, a VDDS system composed...
In this paper, the problem of a class of hyperredundant arms with continuum elements that performs the grasping function by coiling is discussed. This function is often met in the animal world as the elephant's trunk or octopus tentacle. First, the dynamic model in 3D-space is developed. The equations that describe the motion of the arm that carries a load by coiling are inferred. The stability of...
We investigate how unmanned aerial vehicles (UAVs) with flexible wings can be designed to exploit the aeroelasticity of wing deformation that is present in bat wings, with a view to improve the efficiency of flight. We constructed a robotic bat wing with fully passive elastic wing-folding properties. The robotic wing is powered by a gearbox running two synchronised motors, effectively providing one...
Flocking simulates the motion of a flock, which is well known as artificial life algorithms. By using the flocking, we can express the motion of the group such as fishes, birds, or crowded animals in computer graphics. In order to render flocking more realistically, we have devised a method that adds some dynamic conditions into flocking computation. The additional external force and the moving coordinated...
We present a hierarchical approach to compress large dimensional vectors using hyper spherical hashing functions. We provide a practical solution for learning hyper spherical hashing functions by partitioning the vectors and learning hyper spheres in subspaces. Our method is an efficient way to preserve the hashing properties of sub-space hashing functions to generate the full-hashing functions in...
This paper describes a trust-based vehicle controller that can be tuned to ensure decentralized string stability in a convoy. The controller leverages the RoboTrust algorithm to mitigate risks associated with trust-based vulnerabilities, such as cyber attacks, poor decisions, and malfunctions. In our scenario, we simulate a simple convoy mission in which twelve vehicles move together between waypoints,...
Dimensionality reduction aims at providing faithful low-dimensional representations of high-dimensional data. Its general principle is to attempt to reproduce in a low-dimensional space the salient characteristics of data, such as proximities. A large variety of methods exist in the literature, ranging from principal component analysis to deep neural networks with a bottleneck layer. In this cornucopia,...
Breast cancer is a mysterious disease that forms through the formation of cancer in the cells of the breast. It is one of the most dangerous cancer diagnosed in women and may lead to the increasing number of deaths all over the world. In this paper, Gradient Vector Flow (GVF) Snake technique is proposed to detect cancerous cells in breast tissues. Ten images of mammograms were tested by using the...
This paper is devoted to the problem of modeling and position/force tracking for nonholonomic dynamic systems with affine constraints. The rigorous derivation of dynamic model is given. By reasonably introducing so-called internal state vector, a reduced dynamic model, which is suitable for control design, is addressed. Based on the sliding-mode theory, an adaptive control strategy is then derived,...
Currently in robotics field, various new forms of robots are emerged that are different from existing robots. One of them is the mobile robot having a tensegrity structure. In this paper, the tensegrity is employed for a design of a mobile robot that can be used in irregular environment. But the tensegrity structure is highly nonlinear; so it is very difficult to control. In order to deal with this...
Most of molecular interactions often occur in feature regions of molecular surfaces such as convex regions, cavities or pockets. In this paper we propose a method to identify these feature regions by expanding the molecular surface to its surrounding spherical surface, that is, a 1-1 mapping is established between them. According to the expansion distance, feature regions can be determined to be concave...
Evolutionary Computation has been suggested as a means of providing ongoing adaptation of robot controllers. Most often, using Evolutionary Computation to that end focuses on recovery of acceptable robot performance with less attention given to diagnosing the nature of the failure that necessitated the adaptation. In previous work, we introduced the concept of Evolutionary Model Consistency Checking...
In this work the design of a linear observer-linear controller robust output feedback scheme is introduced for simultaneous trajectory tracking of position and force in fully actuated robot manipulators. The unknown state-dependent additive nonlinearity influencing the input-output description is modeled as an absolutely bounded “time-varying perturbation”. Generalized Proportional Integral (GPI)...
This paper presents the design steps and implementation results of a hybrid force/position control of the arm. The HFP control is based on a Proportional-Derivative Controller combined with feed-forward position control and multi-stage Infinite Impulse Response (IIR) filter in the joint space position control loop. In the outer loop, a resolved-velocity force control scheme is used. The performance...
By changing the impedance of a manipulator according to the target object and the type of operation, it is possible to improve the operation efficiency. Researches on how to change the impedance of a slave manipulator in a tele-operation system according to the intention of an operator are underway. However, in most cases, change of the impedance is applied to all directions by the same magnitude...
This paper investigates the possibility and fundamental properties of limit cycle walking on slippery road surface. First, we develop the mathematical model of a planar underactauted biped robot with an upper body that walks while sliding on oily/ice floor. Second, we conduct numerical simulations to show that stable gait generation can be achieved by applying a simple output following control to...
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