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High center of mass vehicles are likely to rollover in extreme maneuvers. Available works present control strategies to prevent rollover. In these works, however, other important parameters such as path trajectory tracking are not a main concern. In this paper conflicts between rollover prevention and trajectory tracking is investigated. Model predictive control (MPC) is adopted to predict and avoid rollover while tracking desired trajectory. For this regard a model based future error estimation is introduced. The control framework predicts both rollover and trajectory error simultaneously. It avoids rollover while tries to track the trajectory. Simulation results for two controllers with... 

In this paper, the swing-up problem of the Furuta pendulum has been solved by introducing a new combined method based on the frequency response, and the sliding mode method. Furthermore, a trajectory tracking controller has been introduced and applied to the Furuta pendulum; which the pendulum remained regulated at the upward position, while the arm tracks a desired time-varying trajectory. The hierarchical sliding mode control (HSMC) approach has been employed to achieve the mentioned goals. The Furuta system is made up of two subsystems. Based on this physical structure, the hierarchical structure of the sliding surfaces is designed as follows: first, the sliding surface of each subsystem... 

In this paper a neural network decentralized control for trajectory tracking of robot manipulators is developed. The proposed decentralized control allows the overall closed-loop system to be stabilized while making the tracking error to be uniformly ultimately bounded (UUB), without having any prior knowledge of the robot manipulator dynamics. The interconnections in the dynamic equations of each subsystem are considered with unknown nonlinear bounds. The RBF neural networks (RBFNNs) are proposed to model the unknown nonlinear dynamics of the robots and the interconnection terms. Using Lyapunov method, the stability of the overall system is investigated, © 2005 IEEE  

In this paper an adaptive fuzzy decentralized control algorithm for trajectory tracking of robot manipulators is developed. The proposed decentralized control algorithm allows the overall closed-loop system to be stabilized while making the tracking error to be uniformly ultimately bounded (UUB), without having any prior knowledge of the robot manipulator dynamics. The interconnections in the dynamic equations of each subsystem are considered with unknown nonlinear bounds. The adaptive fuzzy neural networks (AFNNs) are proposed to model the unknown nonlinear dynamics of the robots and the interconnection terms. Using Lyapunov method, the stability of the overall system is investigated. ©... 

The development and the implementation of a new guidance law are addressed for a six dimensional trajectory tracking problem, three dimensions for position tracking and three dimensions for velocity tracking, of a micro air vehicle. To generate the desired trajectory a virtual leader is defined which is moved in space. In the guidance law, position and velocity feedbacks are used by fuzzy controllers to generate two acceleration commands. Then, a fuzzy coordinator is applied to coordinate the acceleration commands. Nonlinear six-degree-of-freedom equations of motion are used to model the vehicle dynamics. Also, a bank-to-turn acceleration autopilot for vehicle is considered to follow the... 

A novel fault-tolerant model predictive control (MPC)-based trajectory tracking approach for an aerial vehicle is presented in this study. A generalised online sequential extreme learning machine is introduced first to identify the corresponding coefficients of actuator faults. Subsequently, a robust trajectory tracking control is developed based on MPC, where the system constraints can be effectively considered in the designed control scheme. Trajectory tracking control is achieved by controlling only the acceleration of the aerial robot in the MPC structure. This leads to less computational burden and faster closed-loop dynamics. In addition, an effective disturbance observer is employed,... 

The combination of pursuit and line of sight guidance laws, called PLOS, is used to steer an unmanned aerial vehicle along a desired path. In the previous studies, the parameters of this guidance law are tuned by trial and error and are constant, during the flight. In this research, it will be shown that the optimal value of these parameters depends on the initial conditions of the problem and the wind conditions. For this reason, a fuzzy system is proposed to generate the instantaneous optimal value of these parameters, in such a way that the flying vehicle converges to the desired path in less time and follows it more accurately, in the presence of wind. For this purpose, a cost function... 

Background: An effective master robot for haptic tele-surgery applications needs to provide a solution for the inversed movements of the surgical tool, in addition to sufficient workspace and manipulability, with minimal moving inertia. Method: A novel 4+1-DOF mechanism was proposed, based on a triple parallelogram linkage, which provided a Remote Center of Motion (RCM) at the back of the user's hand. The kinematics of the robot was analyzed and a prototype was fabricated and evaluated by experimental tests. Results: With a RCM at the back of the user's hand the actuators far from the end effector, the robot could produce the sensation of hand-inside surgery with minimal moving inertia. The... 

A robotic manipulator is modelled as a cantilever rotating Euler-Bernoulli beam. Two dynamic transfer functions are derived to describe beam tip motion and angular rotation in terms of the desired angular rotation. Torque disturbance, imprecision in the payload mass, unknown properties of the manipulator link are sources of uncertainty. The objective is to achieve a desired angular rotation while the vibration of manipulator tip is suppressed. The control input of the system is an external driving torque. The -synthesis control approach is used and an H optimal robust controller is developed based on the DK-iteration algorithm. Results show that the designed controller guarantees the robust... 

In this paper, a robotic manipulator modelled as a cantilever rotating Euler-Bernoulli beam is considered. Control objective is achieving a desired angular rotation of the manipulator tip while its lateral vibration is suppressed. An external driving torque is the control input of the system. Two dynamic transfer functions are derived to describe beam tip motion and angular rotation in terms of the desired angular rotation. After state-space representation of the problem, an observer is designed to estimate state variables of the system. Then, a feedback control is designed for both regulation and tracking objectives. Eigenvalues are chosen such that an appropriate response is achieved while... 

In this paper, a problem of boundary feedback stabilization of second order hyperbolic partial differential equations (PDEs) is considered. These equations serve as a model for physical phenomena such as oscillatory systems like strings and beams. The controllers are designed using a backstepping method, which has been recently developed for parabolic PDEs. With the integral transformation and boundary feedback the unstable PDE is converted into a system which is stable in sense of Lyapunov. Then taylorian expansion is used to achieve the goal of trajectory tracking. It means design a boundary controller such that output of the system follows an arbitrary map. The designs are illustrated... 

In this paper, a problem of boundary feedback stabilization of second order hyperbolic partial differential equations (PDEs) is considered. These equations serve as a model for physical phenomena such as oscillatory systems like strings and beams. The controllers are designed using a backstepping method, which has been recently developed for parabolic PDEs. With the integral transformation and boundary feedback the unstable PDE is converted into a system which is stable in sense of Lyapunov. Then taylorian expansion is used to achieve the goal of trajectory tracking. It means design a boundary controller such that output of the system follows an arbitrary map. The designs are illustrated... 

In this paper vehicle path-following in the presence of rollover risk is investigated. Vehicles with high centre of mass are prone to roll instability. Untripped rollover risk is increased in high centre of gravity vehicles and high-friction road condition. Researches introduce strategies to handle the short-duration rollover condition. In these researches, however, trajectory tracking is affected and not thoroughly investigated. This paper puts stress on tracking error from rollover prevention. A lower level model predictive front steering controller is adopted to deal with rollover and tracking error as a priority sequence. A brake control is included in lower level controller which... 

A 3-D Hough transform is introduced for detection of linear trajectories in a 3-D data space. Data space is constructed from returned radar data using range, bearing, and time information. This information is then mapped into a 3-D Cartesian data space. The constant velocity target trajectories appear as straight lines in this space, and are detected by the usage of 3-D Hough transform. The efficacy of the 3-D Hough transform is verified by simulation. In comparison with the 2-D case, when only the range-time information is used, the 3-D Hough transform has a better performance. © 2008 IEEE  

This research deals with developing an intelligent trajectory tracking control approach for an aircraft in the presence of internal and external disturbances. Internal disturbances including actuators faults, unmodeled dynamics, and model uncertainties as well as the external disturbances such as wind turbulence significantly affect the performance of the common trajectory tracking control approaches. There are several fault-tolerant control approaches in the literature to overcome the effects of specific actuator or sensor faults during the flight. However, trajectory tracking control of an air vehicle in the presence of unexpected faults and simultaneous presence of wind turbulence is... 

Differential Evolution (DE) and Genetic Algorithms (GA) are population based search algorithms that come under the category of evolutionary optimization techniques. In the present study, these evolutionary methods have been utilized to conduct the optimum design of a fuzzy controller for mobile robot trajectory tracking. Comparison between their performances has also been conducted. In this paper, we will present a fuzzy controller to the problem of mobile robot path tracking for a CEDRA rescue robot. After designing the fuzzy tracking controller, the membership functions will be optimized by evolutionary algorithms in order to obtain more acceptable results  

Differential Evolution (DE) and Genetic Algorithms (GA) are population based search algorithms that come under the category of evolutionary optimization techniques. In the present study, these evolutionary methods have been utilized to conduct the optimum design of a fuzzy controller for mobile robot trajectory tracking. Comparison between their performances has also been conducted. In this paper, we will present a fuzzy controller to the problem of mobile robot path tracking for a CEDRA rescue robot. After designing the fuzzy tracking controller, the membership functions will be optimized by evolutionary algorithms in order to obtain more acceptable results