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The lift-and-carry of non-rigid objects is challenging for both people and bipedal robots. Examples include lifting and carrying jugs, jerry cans or bags that are respectively filled with water, gasoline or sand. Carrying such objects often makes it difficult to walk due to the shifting center-of-mass. As such, tripping and falling are risks. Such lift-and-carry is a common material handling task...
One of the intriguing problems in nonlinear unmanned aerial vehicle (NUAV) control using one of its linearized model based controllers at the inner loop is generating admissible control inputs for which the aircraft trajectories are confined to its stability region. It is an initial condition selection problem that is not necessarily applied at initial time but can be applied at any part of the flight...
The dynamics of a human operated nonlinear unmanned aerial vehicle (NUAV) with a given controller at the inner loop is governed by the admissible nonzero initial conditions and the pilot inputs. The movements of the joystick connected to the throttle and the control surfaces in a way are the indications of the pilot decision points to operate the stabilized NUAV. If these decisions fall short to avoid...
In this paper, input delay theory is used as a key tool to design an effective anti-windup compensator which is applied to active queue management (AQM) at router to avoid congestion. The desired anti-windup compensator can be computed by the solution of convex optimization problem. The simulation results suggest that our methodology is effective and is an improvement over previous ones.
In this paper we tackle the problem of collision avoidance of ground vehicles in a platoon. In this framework, we focus on a single vehicle, and we guarantee that a given safe set is not exited during a mission. More specifically, we consider the yaw-lateral motion of a two-wheel vehicle subject to a side wind, and we design a state-feedback controller such that the vehicle follows the nominal trajectory...
The dynamic Shapley Value for N-customers and M-suppliers in two-stage minimum cost spanning forest game is considered. Define the players' cooperative behavior. Selecting strategies, players build a minimum cost spanning forest at each stage. At second stage, there is a particular player x ∊ N may drop out of the game. The probability p of the player's leaving depends solely upon all players' behavior...
This paper investigates the globally tracking control problem for a class of uncertain nonlinear MIMO systems with prescribed performance. Firstly, we import a compressed function to transform the tracking error into one that stays in a compact set. Secondly, we use the prescribed performance bounded (PPB) control method to prescribe the trajectory of the transformed error. As a result, for any given...
We address the problem of finding useful invariant funnels for dynamic walking robots, i.e. sets of initial conditions from which continued walking in a stable manner is guaranteed. The construction is based on transverse dynamics and sum-of-squares verification. This paper makes two main contributions: firstly, we show that for typical models of walking robots the construction of such funnels can...
In the article the game-theoretic model of limited resource extraction by competitive enterprises in terms of differential non-zero sum games is considered. The Nash equilibrium is found and the cooperative variant of the game investigated, the Shapley value constructed and its dynamic stability (time-consistency) investigated. As the results of this work were found the conditions on the input parameters...
This article discusses the implementation of an infinite-horizon model predictive control approach that is based on representing input and state trajectories by a linear combination of basis functions. An iterative constraint sampling strategy is presented for guaranteeing constraint satisfaction over all times. It will be shown that the proposed method converges. In addition, we will discuss the...
This paper is concerned with sliding sector based variable structure control design of a class of Itô-type stochastic Markov jump system subject to transition rate uncertainties and actuator failure. First, some notions about the sliding-sector for the stochastic Markov jump systems are presented. Sufficient conditions for the design of PR-sliding sector are then established in the framework of linear...
We propose a control law for stabilization of a quadrotor-load system, and provide conditions on the control law's gains that guarantee exponential stability of the equilibrium. The system is composed of a load and an unmanned aerial vehicle (UAV) attached to each other by a cable of fixed length, which behaves as a rigid link under tensile forces; and the control input is composed of a three dimensional...
This paper deals with the time-varying formation tracking control problem for multiple unmanned aerial vehicle (multi-UAV) systems, where the UAVs are required to form a predefined time-varying formation while tracking the trajectory of the leader. A finite-time formation tracking control law is designed to realize time-varying formation tracking by utilizing nonsingular fast terminal sliding mode...
This paper discusses a novel hybrid integrator design that (a) gives improved low-frequency disturbance rejection properties under double-integrator control, but (b) avoids the unwanted occurrence of overshoot and settling effects otherwise resulting from adding an extra linear integrator. The main principle behind this new design is that the resulting hybrid element generates a continuous control...
This paper addresses the assist-as-needed (AAN) control problem for robotic orthoses. The objective is to design a stable AAN controller with an adjustable assistance level. The controller aims to follow a desired trajectory while allowing an adjustable tracking error with low control effort to provide a freedom zone for the user. By ensuring the stability of the system and providing the freedom zone,...
This paper describes the design and implementation of a repetitive controller (RC) for tracking periodic trajectories in aerial robots, such as unmanned aerial vehicles (UAVs). The RC is ideally suited for situations where the robot is required to execute a defined flight pattern, over and over again in a periodic fashion. Applications include precision agriculture, and search and rescue, where the...
The goal of this paper is to study switching stabilization problems for discrete-time switched linear systems (SLSs). To analyze the switching stabilizability, we introduce the notion of graph control Lyapunov functions (GCLFs). The GCLF is a set of Lyapunov functions which satisfy several Lyapunov inequalities associated with a weighted directed graph (digraph). Each Lyapunov function represents...
This paper investigates the stabilization of three-dimensional fractional-order chaotic systems, by a novel sliding mode control scheme based on Lyapunov stability theorem. The proposed controller which only contains a single state variable is simple both to design and to implement. Numerical simulation examples for the Chen chaotic fractional-order system are given to demonstrate the effectiveness...
We introduce a novel distributed control architecture for a class of nonlinear dynamical agents moving in the “string” formation, while guaranteeing trajectory tracking and collision avoidance. Each autonomous agent uses information and relative measurements only with respect to its predecessor in the string. The performance of the scheme is entirely scalable with respect to the number of agents in...
Hexapod legged robot's missions, particularly in irregular and dangerous areas, require high stability and high precision. In this paper, we consider the rectangular architecture body of legged robots with six legs distributed symmetrically along two sides, each leg contains three degrees of freedom for greater mobility. The aim of this work is planning tripod gait trajectory, based on the computing...
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