scholarly journals Speed and Heading Control of an Unmanned Surface Vehicle Based on State Error PCH Principle

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Chengxing Lv ◽  
Haisheng Yu ◽  
Zhili Hua ◽  
Lei Li ◽  
Jieru Chi
Keyword(s):  
Control Algorithm ◽  
Degrees Of Freedom ◽  
Closed Loop ◽  
Control Mechanism ◽  
Energy Shaping ◽  
Control Scheme ◽  
Heading Control ◽  
Overall Stability ◽  
Three Degrees Of Freedom ◽  
State Error

This paper proposes a novel nonlinear control scheme based on energy-shaping (ES) principle and state error port-controlled Hamiltonian (PCH) systems for unmanned surface vehicles (USV) system. The PCH model of three degrees of freedom for USV kinetics system is established. By the ES principle, interconnection assignment and damping injection method is applied to the speed and heading control of the closed-loop USV system to realize an overall stability of control mechanism. Simulation results show that the validity and stability of control algorithm can be satisfied with the performance in speed and heading tracking of which the high simplification and portability make it applicable to the various region.

scholarly journals Open-closed Iterative Learning Control Algorithm for Exoskeleton Rehabilitation Purposes

2019 ◽  
Vol 292 ◽  
pp. 01010
Author(s):  
Mihailo Lazarević ◽  
Nikola Živković ◽  
Darko Radojević
Keyword(s):  
Iterative Learning Control ◽  
Control Algorithm ◽  
Closed Loop ◽  
Learning Control ◽  
Open Loop ◽  
Iterative Learning ◽  
Control Law ◽  
Exact Linearization ◽  
Outer Loop ◽  
Control Scheme

The paper designs an appropriate iterative learning control (ILC) algorithm based on the trajectory characteristics of upper exosk el eton robotic system. The procedure of mathematical modelling of an exoskeleton system for rehabilitation is given and synthesis of a control law with two loops. First (inner) loop represents exact linearization of a given system, and the second (outer) loop is synthesis of a iterative learning control law which consists of two loops, open and closed loop. In open loop ILC sgnPDD2 is applied, while in feedback classical PD control law is used. Finally, a simulation example is presented to illustrate the feasibility and effectiveness of the proposed advanced open-closed iterative learning control scheme.

Robust Autopilot Design for Unmanned Underwater Vehicle Based on H∞ Mixed Sensitivity

2012 ◽  
Vol 457-458 ◽  
pp. 764-772 ◽  
Author(s):  
Fang Rong Wang ◽  
Ru Wen Kan ◽  
Shu Nan Liu ◽  
Xu Bin Dong ◽  
Tao Shang ◽  
...  
Keyword(s):  
Control Algorithm ◽  
Degrees Of Freedom ◽  
High Efficiency ◽  
System Modeling ◽  
Nonlinear Problems ◽  
Underwater Vehicle ◽  
Unmanned Underwater Vehicle ◽  
Navigation Simulation ◽  
Underwater Navigation ◽  
Three Degrees Of Freedom

As the complexity of marine environment and the existence of uncertain factors along with Unmanned Underwater Vehicle (UUV) dynamics itself bringing many nonlinear problems, it is difficult to control the navigation in accordance with a predetermined trajectory. Based on the UUV dynamics analysis and system modeling, this paper decoupled its control system into three sub-control systems, designed robust autopilot using H∞ mixed sensitivity control algorithm to generate the low-order controller to achieve independent control of three degrees of freedom. Eventually, the underwater navigation simulation results show that the proposed method can provide better control performance and the method is feasible and high efficiency in actual applications.

Optimal Backstepping Control of a VR Spherical Motor

2000 ◽  
Author(s):  
Kok-Meng Lee ◽  
Raye Sosseh
Keyword(s):  
Degrees Of Freedom ◽  
Control Design ◽  
Design Tool ◽  
Spherical Motor ◽  
Lyapunov Techniques ◽  
Variable Reluctance ◽  
Output Torque ◽  
Minimum Total Energy ◽  
Overall Stability ◽  
Three Degrees Of Freedom

Abstract This paper considers the control of a variable reluctance (VR) spherical motor that offers some unique features by combining the roll, pitch and yaw motion in a single joint. The 3-DOF VR motor has multiple independent inputs, and the output torque is direction varying and orientation-dependent and as a result, the control for such a motor is significantly more challenging than the single-axis motor. We formulate a new three-degrees-of-freedom (3-DOF) VR motor control design tool using backstepping, where the inputs are optimized to achieve minimum total energy consumed. The torque has been derived as a linear combination of the square of the input currents, a form computationally friendlier than its quadratic counterpart for real-time implementation. The overall stability of the system is shown using Lyapunov techniques. Simulation results are illustrated to show the performance of the controller.

Operational Space Prescribed Tracking Performance and Compliance in Flexible Joint Robots

2015 ◽  
Vol 137 (7) ◽  
Author(s):  
Abdelrahem Atawnih ◽  
Zoe Doulgeri ◽  
George A. Rovithakis
Keyword(s):  
Degrees Of Freedom ◽  
Position Tracking ◽  
Admittance Control ◽  
Flexible Joint ◽  
Flexible Joint Robots ◽  
Operational Space ◽  
Control Scheme ◽  
Simulation Results ◽  
Flexible Joint Manipulator ◽  
Three Degrees Of Freedom

In this work, an admittance control scheme is proposed utilizing a highly robust prescribed performance position tracking controller for flexible joint robots which is designed at the operational space. The proposed control scheme achieves the desired impedance to the external contact force as well as superior position tracking in free motion without any robot model knowledge, as opposed to the torque based impedance controllers. Comparative simulation results on a three degrees-of-freedom (3DOF) flexible joint manipulator, illustrate the efficiency of the approach.

Model-Based Control of Three Degrees of Freedom Robotic Bulldozing

2013 ◽  
Vol 136 (2) ◽  
Author(s):  
Scott G. Olsen ◽  
Gary M. Bone
Keyword(s):  
Material Removal Rate ◽  
Material Removal ◽  
Control Algorithm ◽  
Degrees Of Freedom ◽  
Position Control ◽  
Removal Rate ◽  
Optimal Controller ◽  
Control Laws ◽  
Rule Based ◽  
Three Degrees Of Freedom

This brief paper investigates the control of a robotic bulldozing operation. Optimal blade position control laws were designed based on a hybrid dynamic model to maximize the predicted material removal rate of the bulldozing process. Experiments were conducted with a scaled-down robotic bulldozing system. The control laws were implemented with various tuning values. As a comparison, a rule-based blade control algorithm was also designed and implemented. The experimental results with the best optimal controller demonstrated a 33% increase in the average material removal rate compared to the rule-based controller.

scholarly journals Extending model-mediation method to multi-degree-of-freedom teleoperation systems experiencing time delays in communication

Robotica ◽  
2015 ◽  
Vol 35 (5) ◽  
pp. 1121-1136 ◽  
Author(s):  
Emre Uzunoğlu ◽  
Mehmet İsmet Can Dede
Keyword(s):  
Time Delays ◽  
Control Algorithm ◽  
Degrees Of Freedom ◽  
Control Method ◽  
Test Results ◽  
Bilateral Teleoperation ◽  
Extended Version ◽  
Teleoperation System ◽  
Teleoperation Systems ◽  
Three Degrees Of Freedom

SUMMARYIn this study, a bilateral teleoperation control algorithm is developed in which the model-mediation method is integrated with an impedance controller. The model-mediation method is also extended to three-degrees-of-freedom teleoperation. The aim of this controller is to compensate for instability issues and excessive forcing applied to the slave environment stemming from time delays in communication. The proposed control method is experimentally tested with two haptic desktop devices. Test results indicate that stability and passivity of the bilateral teleoperation system is preserved under variable time delays in communication. It is also observed that safer interactions of the slave system with its environment can be achieved by utilizing an extended version of the model-mediation method with an impedance controller.

Modeling and Controlling the Dynamic Behavior of an Aerial Manipulator

2021 ◽  
pp. 2150044
Author(s):  
Zain Anwar Ali ◽  
Li Xinde
Keyword(s):  
Dynamic Behavior ◽  
Control Algorithm ◽  
Degrees Of Freedom ◽  
Control Mechanism ◽  
Hybrid Control ◽  
External Noise ◽  
Pole Placement ◽  
Aerial Manipulator ◽  
Aerial Vehicle ◽  
Model Reference Adaptive

Unmanned Aerial Vehicles (UAVs) installed with a gripper is an effective and robust way to grab the wanted object from inaccessible locations. In this study, we develop a novel control mechanism to regulate the nonlinear dynamics of the aerial manipulator. In this research, hex-rotor UAV is chosen in order to fulfill the mission requirement in terms of size and weight of the object. It is equipped with a manipulator and the gimbal-based camera that will help to see the desired object and then transport it. The aerial vehicle has six-degrees-of-freedom (6-DOF) and the installed manipulator has 4-DOF which in total makes the 10-DOF aerial manipulator vehicle. At the time of clutching the desired object to eliminate or reduce the external noise, and stabilize the dynamic behavior of the aerial manipulator, we need a robust and efficient controller. To solve the aforementioned problems, this study develops a hybrid control mechanism that tracks and controls the altitude and attitude of UAV after clutching the desired object. The main contribution of this study is to design a control mechanism that includes Model Reference Adaptive Control with an Integrator (MRACI) in conjunction with regulation, pole-placement and tracking (RST) control algorithm. On one hand, the simulation results using MATLAB demonstrate the efficiency of the proposed control mechanism. On the other hand, to cross verify the validity of the proposed control algorithm, we perform the experiment by clutching the desired object at hovering and normal flight operation.

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