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This paper presents the relatively rich and interesting bifurcation structure that is present in the nature of optimal solutions to a multi-robot formation control problem. The problem considered is a two point nonlinear boundary-value problem that can only be solved numerically. Since common numerical solution techniques such as the shooting method are local in nature and hence are difficult to use...
In recent years multiple simultaneous localization and mapping (SLAM) algorithms have been proposed, which address the challenges of 3D environments in combination with six degress of freedom in the robot position. Commonly, solutions based on scan-matching algorithms are applied. In contrast to these approaches, we propose to use a particle filter transferring the concept of the 2D Rao-Blackwellized...
Constrained trajectories for a formation of N aircraft are optimized in terms of kinetic energy, fuel and energy consumption. Each aircraft moves from an initial position, converges to an assigned waypoint, unique for the formation, passes through m assigned waypoints, avoids a designated area and finally passes through a given surface. Airplanes are modeled as 3DOF point masses that always maintain...
A problem associated with motion planning for the assembly of individual modules in a new self-reconfigurable modular robotic system is presented. Modules of the system are independently mobile and can be driven on flat surfaces in a similar fashion to the classic kinematic cart. This problem differs from most nonholonomic steering problems because of an added constraint on one of the internal states...
In this paper five different optimization strategies for kinematically redundant mechanisms, i.e. mechanisms having additional actuator(s) in at least one kinematic chain, are presented. They are based on two main approaches, a discrete optimization and a classical continuous optimization. Exemplarily, a planar, kinematically redundant 3RRR-based mechanism is introduced. The position of its redundant...
Many real life problems can be modeled as nonlinear global optimization problems. Such problems often have multiple local minima and thus require global optimization methods. One of the more recent global optimization tools is known as the filled function method which is a promising way used in unconstrained global optimization. Several filled functions with one or two parameters have already been...
This paper presents a novel planar three-degree-of-freedom pendulum-like underactuated robot. The robot consists of an end-effector with an actuated arm suspended on a cable wound on a reel. The robot can achieve full planar point-to-point motion (position and orientation) with zero-velocity landing by swinging itself as children do on playground swings. The equations of motion of the underactuated...
We present an algorithm that probabilistically covers a bounded region of the state space of a nonlinear system with a sparse tree of feedback stabilized trajectories leading to a goal state. The generated tree serves as a lookup table control policy to get any reachable initial condition within that region to the goal. The approach combines motion planning with reasoning about the set of states around...
Skid-steered vehicles, by design, must skid in order to maneuver. The skidding causes the vehicle to behave discontinuously as well as introduces complications to the observation of the vehicle's state, both of which affect a controller's performance. This paper addresses estimation of contact state by applying switched system optimization to estimate skidding properties of the skid-steered vehicle...
We present a novel approach to legged locomotion over rough terrain that is thoroughly rooted in optimization. This approach relies on a hierarchy of fast, anytime algorithms to plan a set of footholds, along with the dynamic body motions required to execute them. Components within the planning framework coordinate to exchange plans, cost-to-go estimates, and “certificates” that ensure the output...
Manipulative operation of a target point inside a deformable object by a robotic system is necessary in many medical and industrial applications. However, this is a challenging problem because of the difficulty of imposing the motion of the target point by a finite number actuation points located at the boundary of the deformable object. In this paper, an approach towards positioning operation of...
We present a novel combination of motion planning techniques to compute motion plans for robotic arms. We compute plans that move the arm as close as possible to the goal region using sampling-based planning and then switch to a trajectory optimization technique for the last few centimeters necessary to reach the goal region. This combination allows fast computation and safe execution of motion plans...
We present a control architecture for fast quadruped locomotion over rough terrain. We approach the problem by decomposing it into many sub-systems, in which we apply state-of-the-art learning, planning, optimization and control techniques to achieve robust, fast locomotion. Unique features of our control strategy include: (1) a system that learns optimal foothold choices from expert demonstration...
This paper develops and tests a novel rapid updating technique for use with a nonlinear branch and bound optimisation method, tailored for finding optimal trajectories for a vehicle constrained to avoid fixed obstacles. The key feature of the rapid updating technique developed is the ability to increment and re-arrange the existing search tree reducing the amount of computation taken to find a new...
The present work was aimed for updating (optimizing) the design of the research-oriented roll-type electrostatic separator ELSEP. The new equipment has several distinctive features: (i) large variety of corona and electrostatic electrodes; (ii) reversible 100 kV, 3 mA DC high-voltage supply; (iii) variable-speed roll drive with induction motor and frequency convertor; (iv) ergonomic control panel...
A novel node localization scheme using a mobile beacon is proposed. In this scheme, the number and positions of the virtual beacons is determined based on equilateral triple optimal coverage, so sufficient localization information can be obtained for each unknown node. And we apply the ant colony algorithm (ACA) to get the optimal path that mobile beacon tour all the virtual beacons. In order to further...
We present a simple and efficient feature modeling approach for tracking the pitch of two speakers speaking simultaneously. We model the spectrogram features of single speakers using Gaussian mixture models in combination with the minimum description length model selection criterion. Furthermore, the mixture maximization (MIXMAX) interaction model is employed to yield a probabilistic representation...
In this paper we propose PARINET, a new access method to efficiently retrieve the trajectories of objects moving in networks. The structure of PARINET is based on a combination of graph partitioning and a set of composite B+-tree local indexes. PARINET is designed for historical data and relies on the distribution of the data over the network as for historical data, the data distribution is known...
This paper presents an innovative 3D analytical algorithm for the resolution of the pair-wise non-cooperative collision avoidance problem between aircrafts. The proposed algorithm addresses the above described problem by using an innovative approach, based on the consideration of a cylindrical safety bubble, and it is able to obtain an optimal three-dimensional analytical solution for this problem...
This paper proposes a new method with a three-level architecture named tactics template (TT) for tactical aircraft attack path planning and optimization. Distinguished from the traditional path planning algorithms, the TT method extends the ability to deal with tactics and actions rather than trajectories, which maintains the benefits of traditional path planning algorithms while well-satisfying pilot's...
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