scholarly journals Visual Tracking Control of Cable-Driven Hyper-Redundant Snake-Like Manipulator

2021 ◽  
Vol 11 (13) ◽  
pp. 6224
Author(s):  
Qisong Zhou ◽  
Jianzhong Tang ◽  
Yong Nie ◽  
Zheng Chen ◽  
Long Qin
Keyword(s):  
Visual Tracking ◽  
Tracking Control ◽  
Control Method ◽  
Adaptive Optimization ◽  
Tracking Errors ◽  
Kinematics Model ◽  
Compound Control ◽  
Original Intention ◽  
Control Scheme ◽  
Specific Geometry

The cable-driven hyper-redundant snake-like manipulator (CHSM) inspired by the biomimetic structure of vertebrate muscles and tendons, which consists of numerous joint units connected adjacently driven by elastic materials with hyper-redundant DOF, performs flexible kinematic skills and competitive compound capability under complicated working circumstances. Nevertheless, the drawback of lacking the ability to perceive the environment to perform intelligently in complex scenarios leaves a lot to be improved, which is the original intention to introduce visual tracking feedback acting as an instructor. In this paper, a cable-driven snake-like robotic arm combined with a visual tracking technique is introduced. A visual tracking approach based on dual correlation filter is designed to guide the CHSM in detecting the target and tracing after its trajectory. Specifically, it contains an adaptive optimization for the scale variation of the tracking target via pyramid sampling. For the CHSM, an explicit kinematics model is derived from its specific geometry relationships and followed by a simplification for the inverse kinematics based on some assumption or limitation. A control scheme is brought up to combine the kinematics with visual tracking via the processing tracking errors. The experimental results with a practical prototype validate the availability of the proposed compound control method with the derived kinematics model.

Adaptive attitude-tracking control of spacecraft considering on-orbit refuelling

2020 ◽  
pp. 014233122097313
Author(s):  
Yiqi Xu
Keyword(s):  
Tracking Control ◽  
Closed Loop ◽  
Closed Loop System ◽  
Tracking Errors ◽  
Attitude Tracking ◽  
Control Scheme ◽  
Inertia Model ◽  
And Performance ◽  
Attitude Tracking Control ◽  
The Stability

This paper studies the attitude-tracking control problem of spacecraft considering on-orbit refuelling. A time-varying inertia model is developed for spacecraft on-orbit refuelling, which actually includes two processes: fuel in the transfer pipe and fuel in the tank. Based upon the inertia model, an adaptive attitude-tracking controller is derived to guarantee the stability of the resulted closed-loop system, as well as asymptotic convergence of the attitude-tracking errors, despite performing refuelling operations. Finally, numerical simulations illustrate the effectiveness and performance of the proposed control scheme.

Sliding Control Without Reaching Phase and Its Application to Bipedal Locomotion

1993 ◽  
Vol 115 (3) ◽  
pp. 447-455 ◽  
Author(s):  
Tai-Heng Chang ◽  
Yildirim Hurmuzlu
Keyword(s):  
Trajectory Planning ◽  
Planning Process ◽  
Control Method ◽  
Variable Structure ◽  
Bipedal Locomotion ◽  
Tracking Errors ◽  
Structure Control ◽  
Control Scheme ◽  
Lyapunov’S Second Method ◽  
Planning Problems

A new variable structure control law based on the Lyapunov’s second method that can be used in trajectory planning problems of robotic systems is developed. A modified approach to the formulation of the sliding domain equations in terms of tracking errors has been presented. This approach possesses three distinct advantages: (i) it eliminates the reaching phase, (ii) it provides means to predict the entire motion and directly control the evolution of tracking errors, (iii) it facilitates the trajectory planning process in the joint and/or cartesian spaces. A planar, five-link bipedal locomotion model has been developed. Five constraint relations that cast the motion of the biped in terms of four parameters are developed. The new control method is applied to regulate the locomotion of the system according to the five constraint relations. Numerical simulation is performed to verify the ability of the controller to achieve steady gait by applying the proposed control scheme. Bifurcation diagrams of the periodic motions of the biped are used to demonstrate the improvements in controller performance that arise from the application of the proposed method.

Tracking Control of Automatic Pipe Cutting Robot with Magnetic Binder

2006 ◽  
Vol 505-507 ◽  
pp. 1201-1206
Author(s):  
Sung Soo Rhim ◽  
Soon Geul Lee
Keyword(s):  
Tracking Control ◽  
Magnetic Force ◽  
Welding Process ◽  
Gravitational Effect ◽  
Welding Robot ◽  
Tracking Errors ◽  
Control Scheme ◽  
Repetitive Learning ◽  
Errors Analysis

An automatic pipe cutting/welding robot with a magnetic binder, which is named APCROM, is developed and its tracking control is studied in this paper. Using magnetic force the four-wheeled mobile robot binds itself to the pipe and executes automatic pipe cutting/welding process. As APCROM rotates around the cylindrical pipe laid in the gravitational field, the gravity effect on the movement of the robot varies. The varying gravitational effect deteriorates the tracking performance of the robot and degrades the quality of the pipe cutting/welding process. To maintain a constant velocity and consistent cutting/welding performance, the authors adopt a repetitive learning controller, which learns through practice the required effort to cancel the tracking errors. Analysis results and experimental results verify the effectiveness of the proposed control scheme.

scholarly journals Fuzzy cerebellar model articulation controller-based adaptive tracking control for load-carrying exoskeleton

2020 ◽  
Vol 53 (7-8) ◽  
pp. 1472-1481
Author(s):  
Han Wu ◽  
Lin Lang ◽  
Honglei An ◽  
Qing Wei ◽  
Hongxu Ma
Keyword(s):  
Tracking Control ◽  
Approximate Model ◽  
Cerebellar Model Articulation Controller ◽  
Tracking Errors ◽  
Trajectory Tracking Control ◽  
Load Variations ◽  
Adaptive Tracking Control ◽  
Control Scheme ◽  
Load Carrying ◽  
Computed Torque

Load-carrying exoskeletons need to cope with load variations, outside disturbances, and other uncertainties. This paper proposes an adaptive trajectory tracking control scheme for the load-carrying exoskeleton. The method is mainly composed of a computed torque controller and a fuzzy cerebellar model articulation controller. The fuzzy cerebellar model articulation controller is used to approximate model inaccuracies and load variations, and the computed torque controller deals with tracking errors. Simulations of an exoskeleton in squatting movements with model parameter changes and load variations are carried out, respectively. The results show a precise tracking response and high uncertainties toleration of the proposed method.

Attitude and height tracking control of unmanned helicopters with disturbances via disturbance observer-based composite dynamic surface control

2021 ◽  
pp. 014233122110232
Author(s):  
Xiangyu Wang ◽  
Ling Han ◽  
Jiyu Liu
Keyword(s):  
Tracking Control ◽  
Disturbance Observer ◽  
Control Design ◽  
Dynamic Surface Control ◽  
Control Technique ◽  
Tracking Errors ◽  
Dynamic Surface ◽  
Surface Control ◽  
Control Scheme ◽  
Tracking Controller

In this paper, the attitude and height tracking control problem is studied for unmanned helicopters with disturbances. To solve the problem, a composite control scheme is proposed based on the combination of dynamic surface control and disturbance observer-based control techniques. The control design includes two parts. In the first part, some nonlinear disturbance observers are designed to accurately estimate the helicopter’s disturbances in different channels. In the second part, based on the disturbance estimates and dynamic surface control technique, a composite dynamic surface tracking controller is designed. Under the proposed composite controller, the attitude and height tracking errors are uniformly ultimately bounded and they can be regulated to be very small by selecting proper controller parameters. For one thing, the proposed control scheme avoids “explosion of terms”, which generally exists in conventional backstepping control and provides a simpler control design. For another thing, without sacrificing the nominal control performances, the anti-disturbance ability of the closed-loop helicopter system is enhanced by using disturbance observers and feedforward compensations. Numerical simulations demonstrate the effectiveness and advantages of the proposed composite tracking controller.

Setpoint Tracking Control With Discrete Actuators Using Controller Switching

2018 ◽  
Author(s):  
Y. Chida ◽  
R. Hara
Keyword(s):  
Steady State ◽  
Lyapunov Function ◽  
Control Problem ◽  
Numerical Simulations ◽  
Tracking Control ◽  
Control Structure ◽  
Control Method ◽  
Tracking Errors ◽  
State Tracking ◽  
Servo Controller

In the present paper, we discuss a setpoint tracking control problem for a plant with discrete actuators. When a conventional linear servo controller is applied to the plant, undesirable periodic vibrations similar to the limit cycle occasionally occur in the output response caused by synergy with the integration of the steady-state tracking errors and the quantized errors of the control inputs. To prevent an undesirable response, a novel control method is proposed, in which the controller switches the control structure based on the value of the Lyapunov function. The effectiveness of the proposed method was verified through numerical simulations.

scholarly journals Trajectory Tracking Control Study of a New Parallel Mechanism with Redundant Actuation

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Haiqiang Zhang ◽  
Hairong Fang ◽  
Dan Zhang ◽  
Qi Zou ◽  
Xueling Luo
Keyword(s):  
Trajectory Tracking ◽  
Tracking Control ◽  
Parallel Mechanism ◽  
Dynamic Models ◽  
Control Method ◽  
Hybrid Control ◽  
Virtual Work ◽  
Redundant Actuation ◽  
Trajectory Tracking Control ◽  
Control Scheme

Parallel mechanisms with redundant actuation are attracting numerous scholars’ research interest due to their inherent advantages. In this paper, an efficient trajectory tracking control scheme for the new redundantly actuated parallel mechanism by integrating force/position hybrid control with the combination of inertia feed-forward control and back propagation (BP) neural network PID control is proposed. The dynamic models including the joint space and task space are formulated explicitly in efficient and compact form by means of the principle of virtual work and d’Alembert formulations. The force/position hybrid control is implemented to perform trajectory tracking and optimize the driving force configuration in MATLAB/Simulink environment, before being applied to an actual parallel mechanism. The illustrative simulation results demonstrate that the force/position hybrid control scheme is available to provide good trajectory tracking performance. Simultaneously, the feasibility of the proposed control scheme is verified by comparison analysis with the aforementioned conventional control method.

A Fuzzy Self-Learning Control Method with Application to Hydroforming Processes

1995 ◽  
Vol 117 (3) ◽  
pp. 297-303 ◽  
Author(s):  
H. J. Park ◽  
H. S. Cho
Keyword(s):  
Tracking Control ◽  
Control Method ◽  
Learning Control ◽  
Design Parameters ◽  
High Quality ◽  
Control Scheme ◽  
Series Of Experiments ◽  
Quality Of Products ◽  
Self Learning

In this paper, a tracking control of hydroforming pressure which is used for precision forming of sheet metals, is considered. In this process, forming pressure of the process needs to be strictly controlled to ensure high quality of the forming products. However, conventional control method alone makes it difficult to achieve satisfactory control performance due to complexities and uncertainties of the process. To overcome this problem, a fuzzy self-learning control scheme is proposed. In the proposed scheme, a series of experiments were performed to show the effectiveness of the proposed control scheme and to investigate influence of the design parameters of the proposed algorithm. The experimental results show that the proposed fuzzy self-learning controller can guarantee good tracking performance and thus, high quality of products even when knowledge of the process is vague, imprecise and fragmentary.

scholarly journals Disturbance Compensation Based Finite-Time Tracking Control of Rigid Manipulator

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Mohamed Elamin Sahabi ◽  
Guipu Li ◽  
Xiangyu Wang ◽  
Shihua Li
Keyword(s):  
Finite Time ◽  
Tracking Control ◽  
Disturbance Observer ◽  
Control Method ◽  
Disturbance Compensation ◽  
Adding A Power Integrator ◽  
Time Simulation ◽  
Control Scheme ◽  
Mismatched Disturbances ◽  
Power Integrator

The finite-time tracking control problem of rigid manipulator system with mismatched disturbances is investigated via a composite control method. The proposed composite controller is based on finite-time disturbance observer and adding a power integrator technique. First, a finite-time disturbance observer is designed which guarantees that the disturbances can be estimated in a finite time. Then, a composite controller is developed based on adding a power integrator approach and the estimates of the disturbances. Under the proposed composite controller, the manipulator position can track the desired position in a finite time. Simulation results show the effectiveness of the proposed control scheme.

scholarly journals Finite-Time Command-Filtered Approximation-Free Attitude Tracking Control of Rigid Spacecraft

2021 ◽  
Author(s):  
Shuzong Xie ◽  
Qiang Chen ◽  
Xiongxiong He ◽  
Meiling Tao ◽  
Liang Tao
Keyword(s):  
Finite Time ◽  
Attitude Control ◽  
Tracking Control ◽  
Tracking Errors ◽  
Attitude Tracking ◽  
Control Scheme ◽  
Rigid Spacecraft ◽  
Lower Complexity ◽  
Attitude Tracking Control ◽  
Function Approximations

Abstract This paper presents a finite-time command-filtered approximation-free attitude tracking control for rigid spacecraft. A novel finite-time prescribed performance function (FTPPF) is first constructed to ensure that the attitude tracking errors converge to the predefined region in finite time. Then, a finite-time error compensation mechanism is constructed and incorporated into the backstepping control design, such that the differentiation of virtual control signals in recursive steps can be avoided to overcome the singularity issue. Compared with most of approximation-based attitude control methods, less computational burden and lower complexity are guaranteed by the proposed approximation-free control scheme due to the avoidance of using any function approximations. Simulations are given to illustrate the efficiency of the proposed method.

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