scholarly journals Time delay control of cable-driven manipulators with artificial bee colony algorithm

2018 ◽  
Vol 42 (2) ◽  
pp. 177-186 ◽  
Author(s):  
Fei Yan ◽  
Yaoyao Wang ◽  
Wei Xu ◽  
Bai Chen
Keyword(s):  
Time Delay ◽  
Artificial Bee Colony ◽  
Control Method ◽  
Weight Ratio ◽  
Time Delay Estimation ◽  
Time Delay Control ◽  
Tuning Method ◽  
Model Free ◽  
Bee Colony ◽  
Delay Control

Cable-driven manipulators (CDM) are widely-used for their unique advantages such as light weight, low moving mass, high payload-to-weight ratio, and large reachable workspace. However, their complex dynamic character and low stiffness with flexible joints make the control design much more difficult than for traditional robot manipulators. In this paper, time delay control (TDC), which combines the proportional-integral–derivative (PID) control method and time delay estimation (TDE) technology, will be investigated to build a model-free controller for CDM. PID parameters are reduced dramatically as TDE compensates for a large proportion of unknown dynamics. To handle the problem in tuning parameters of this controller, artificial bee colony (ABC) algorithm is utilized to obtain optimal parameters of PID. Finally, simulations are conducted to verify the effectiveness of the propose controller and the tuning method.

scholarly journals Robust-adaptive dynamic programming-based time-delay control of autonomous ships under stochastic disturbances using an actor-critic learning algorithm

2021 ◽  
Author(s):  
Hossein Nejatbakhsh Esfahani ◽  
Rafal Szlapczynski
Keyword(s):  
Dynamic Programming ◽  
Time Delay ◽  
Control Algorithm ◽  
Approximate Dynamic Programming ◽  
Robust Adaptive Control ◽  
Stochastic Disturbances ◽  
Time Delay Control ◽  
Model Free ◽  
Delay Control ◽  
Robust Adaptive

AbstractThis paper proposes a hybrid robust-adaptive learning-based control scheme based on Approximate Dynamic Programming (ADP) for the tracking control of autonomous ship maneuvering. We adopt a Time-Delay Control (TDC) approach, which is known as a simple, practical, model free and roughly robust strategy, combined with an Actor-Critic Approximate Dynamic Programming (ACADP) algorithm as an adaptive part in the proposed hybrid control algorithm. Based on this integration, Actor-Critic Time-Delay Control (AC-TDC) is proposed. It offers a high-performance robust-adaptive control approach for path following of autonomous ships under deterministic and stochastic disturbances induced by the winds, waves, and ocean currents. Computer simulations have been conducted under two different conditions in terms of the deterministic and stochastic disturbances and all simulation results indicate an acceptable performance in tracking of paths for the proposed control algorithm in comparison with the conventional TDC approach.

scholarly journals Multiple Input Delays Estimation Using an Artificial Bee Colony Algorithm

2013 ◽  
Vol 2013 ◽  
pp. 1-6
Author(s):  
Wei-Der Chang
Keyword(s):  
Time Delay ◽  
Discrete Time ◽  
Artificial Bee Colony ◽  
Time Delay Estimation ◽  
Delay Estimation ◽  
State Equations ◽  
Bee Colony ◽  
Multiple Input ◽  
Input Delays ◽  
Multiple Input Delays

This paper focuses on the time delay estimation of the system described in the form of discrete-time state equation with multiple input delays. To estimate the input delays, a new evolutionary computation called the artificial bee colony (ABC) algorithm is utilized. This algorithm is originally motivated from the social behaviors of honeybee organization, and it has been proven to be a powerful means for solving the optimized problem. Based on the proposed algorithm, the unknown system input delays can be further solved by minimizing a quadratic cost function of the system. Two illustrative examples are provided to verify the potential of the presented method in the time delay estimation. Some simulations containing different initial condition examinations and appearance of noises are further given. Numerical results show that the proposed method can do well in the multiple inputs delay estimation of discrete-time state equations.

scholarly journals A new fuzzy time-delay control for cable-driven robot

2019 ◽  
Vol 16 (2) ◽  
pp. 172988141983501 ◽  
Author(s):  
Surong Jiang ◽  
Yaoyao Wang ◽  
Feng Ju ◽  
Bai Chen ◽  
Hongtao Wu
Keyword(s):  
Time Delay ◽  
Trajectory Tracking ◽  
Time Delay Estimation ◽  
Delay Estimation ◽  
Experimental Result ◽  
Tracking Accuracy ◽  
Nonlinear Controller ◽  
Time Delay Control ◽  
Delay Control ◽  
Mean Square Errors

To overcome the problems of structural parametric uncertainty and cable transmission model complexity, a nonlinear controller based on time-delay estimation and fuzzy self-tuning is proposed. The unknown dynamics and disturbances are estimated by time delaying the state of motion immediately before. The control gains are self-tuned by a fuzzy controller, which can reduce the errors caused by system’s uncertainties and external disturbances. Compared with the conventional Proportional-derivative (PD) and time-delay control, the result shows that the proposed control scheme based on time-delay estimation can improve the joint trajectory tracking accuracy of cable-driven robot by significantly reducing the control gains. With the PD gains self-tuned by fuzzy strategy, the mean square errors of trajectory tracking are decreased approximately by 5–20% more than the conventional time-delay control with constant gains. In addition, the experimental result shows that the proposed method has an effective inhibitory effect on dead zone in cable-driven joints. Experiment performed on position tracking control of a 2-degree-of-freedom cable-driven robot is presented to illustrate that the controller has the advantages of simple and reliable structure, model-free, strong robustness, and high tracking accuracy.

scholarly journals Velocity-Free Adaptive Time Delay Control of Robotic System

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Shini Chen ◽  
Xia Liu
Keyword(s):  
Time Delay ◽  
Large Time ◽  
Complex Dynamics ◽  
Time Delay Estimation ◽  
Robotic System ◽  
Time Delay Control ◽  
System A ◽  
Delay Control ◽  
Adaptive Time ◽  
The Stability

To improve the trajectory tracking performance of a complex nonlinear robotic system, a velocity-free adaptive time delay control is proposed. First, considering that conventional time delay control (TDC) may cause large time delay estimation (TDE) error under nonlinear friction, a TDC with gradient estimator is designed. Next, since it is complicated and time-consuming to adjust gains manually, an adaptive law is designed to estimate the gain of the gradient. Finally, in order to avoid the measurement of velocity and acceleration in the controller while enabling the robot to implement position tracking, an observer is designed. The proposed control can not only offset the nonlinear terms in the complex dynamics of the robotic system but also reduce the TDE error, estimate the gain of the gradient online, and avoid the measurement of velocity and acceleration. The stability of the system is analyzed via Lyapunov function. Simulations are conducted on a 2-DOF robot to verify the effectiveness of the proposed control.

scholarly journals Adaptive Robust Force Position Control for Flexible Active Prosthetic Knee Using Gait Trajectory

2020 ◽  
Vol 10 (8) ◽  
pp. 2755
Author(s):  
Fang Peng ◽  
Haiyang Wen ◽  
Cheng Zhang ◽  
Bugong Xu ◽  
Jiehao Li ◽  
...  
Keyword(s):  
Time Delay ◽  
Position Control ◽  
Control Method ◽  
Hybrid Control ◽  
Sliding Mode ◽  
Impedance Control ◽  
Joint Stiffness ◽  
Variable Stiffness ◽  
Time Delay Estimation ◽  
Model Free

Active prosthetic knees (APKs) are widely used in the past decades. However, it is still challenging to make them more natural and controllable because: (1) most existing APKs that use rigid actuators have difficulty obtaining more natural walking; and (2) traditional finite-state impedance control has difficulty adjusting parameters for different motions and users. In this paper, a flexible APK with a compact variable stiffness actuator (VSA) is designed for obtaining more flexible bionic characteristics. The VSA joint is implemented by two motors of different sizes, which connect the knee angle and the joint stiffness. Considering the complexity of prothetic lower limb control due to unknown APK dynamics, as well as strong coupling between biological joints and prosthetic joints, an adaptive robust force/position control method is designed for generating a desired gait trajectory of the prosthesis. It can operate without the explicit model of the system dynamics and multiple tuning parameters of different gaits. The proposed model-free scheme utilizes the time-delay estimation technique, sliding mode control, and fuzzy neural network to realize finite-time convergence and gait trajectory tracking. The virtual prototype of APK was established in ADAMS as a testing platform and compared with two traditional time-delay control schemes. Some demonstrations are illustrated, which show that the proposed method has superior tracking characteristics and stronger robustness under uncertain disturbances within the trajectory error in ± 0 . 5 degrees. The VSA joint can reduce energy consumption by adjusting stiffness appropriately. Furthermore, the feasibility of this method was verified in a human–machine hybrid control model.

scholarly journals The Development of Anti-Windup Scheme for Time Delay Control With Switching Action Using Integral Sliding Surface

2003 ◽  
Vol 125 (4) ◽  
pp. 630-638 ◽  
Author(s):  
Sung-Uk Lee ◽  
Pyung Hun Chang
Keyword(s):  
Time Delay ◽  
Sliding Mode ◽  
Control Area ◽  
Time Delay Estimation ◽  
Sliding Surface ◽  
Time Delay Control ◽  
Delay Control ◽  
Switching Action ◽  
Integral Sliding Surface ◽  
The Stability

The Time Delay Control with Switching Action (TDCSA) method, which consists of Time Delay Control (TDC) and a switching action of sliding mode control (SMC), has been proposed as a promising technique in the robust control area where the plant has an unknown dynamics with parameter variations and substantial disturbances are preset. When TDCSA is applied to the plant with saturation nonlinearity, however, the so-called windup phenomenon is observed to arise, causing excessive overshoot and instability. The integral element of TDCSA and the saturation element of a plant cause the windup phenomenon. There are two integral effects in TDCSA. One is the integral effect caused by time delay estimation of TDC. The other is the integral term of an integral sliding surface. To solve this problem, we have proposed an anti-windup scheme method for TDCSA. The stability of the overall system has been proved for a class of nonlinear system. Experimental results show that the proposed method overcomes the windup problem of the TDCSA.

scholarly journals Switched time delay control based on artificial neural network for fault detection and compensation in robot manipulators

2021 ◽  
Vol 3 (4) ◽  
Author(s):  
Dihya Maincer ◽  
Moufid Mansour ◽  
Amar Hamache ◽  
Chemseddine Boudjedir ◽  
Moussaab Bounabi
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Time Delay ◽  
Control Method ◽  
High Gain ◽  
Industrial Applications ◽  
Control Laws ◽  
Time Delay Control ◽  
Delay Control ◽  
Artificial Neural

AbstractThis work proposes a switched time delay control scheme based on neural networks for robots subjected to sensors faults. In this scheme, a multilayer perceptron (MLP) artificial neural network (ANN) is introduced to reproduce the same behavior of a robot in the case of no faults. The reproduction characteristic of the MLPs allows instant detection of any important sensor faults. In order to compensate the effects of these faults on the robot’s behavior, a time delay control (TDC) procedure is presented. The proposed controller is composed of two control laws: The first one contains a small gain applied to the faultless robot, while the second scheme uses a high gain that is applied to the robot subjected to faults. The control method applied to the system is decided based on the ANN detection results which switches from the first control law to the second one in the case where an important fault is detected. Simulations are performed on a SCARA arm manipulator to illustrate the feasibility and effectiveness of the proposed controller. The results demonstrate that the free-model aspect of the proposed controller makes it highly suitable for industrial applications.

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