Software Sensor to Enhance Online Parametric Identification for Nonlinear Closed-Loop Systems for Robotic Applications

This paper proposes an online direct closed-loop identification method based on a new dynamic sliding mode technique for robotic applications. The estimated parameters are obtained by minimizing the prediction error with respect to the vector of unknown parameters. The estimation step requires knowledge of the actual input and output of the system, as well as the successive estimate of the output derivatives. Therefore, a special robust differentiator based on higher-order sliding modes with a dynamic gain is defined. A proof of convergence is given for the robust differentiator. The dynamic parameters are estimated using the recursive least squares algorithm by the solution of a system model that is obtained from sampled positions along the closed-loop trajectory. An experimental validation is given for a 2 Degrees Of Freedom (2-DOF) robot manipulator, where direct and cross-validations are carried out. A comparative analysis is detailed to evaluate the algorithm’s effectiveness and reliability. Its performance is demonstrated by a better-quality torque prediction compared to other differentiators recently proposed in the literature. The experimental results highlight that the differentiator design strongly influences the online parametric identification and, thus, the prediction of system input variables.

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Trajectory Tracking of Underactuated Surface Vessels Based on Hierarchical Sliding Mode

Volume 8B: Ocean Engineering ◽

10.1115/omae2014-24236 ◽

2014 ◽

Author(s):

Cheng Liu ◽

Zaojian Zou ◽

Jianchuan Yin

Keyword(s):

Trajectory Tracking ◽

Degrees Of Freedom ◽

Closed Loop ◽

Sliding Mode ◽

Underactuated System ◽

Sliding Mode Controller ◽

Control Field ◽

Surface Vessels ◽

Underactuated Surface Vessels ◽

Hierarchical Sliding Mode

Trajectory tracking is an importance practice in ship motion control field. It attracts more attention recently due to its difficulties. Trajectory tracking requires the ship to arrive pinpoint location at exact time. It is a underactuated system because the degrees of freedom of control inputs are fewer than the degrees of freedom that needed to be controlled. In this paper, a hierarchical sliding mode controller and a common sliding mode controller are proposed to deal with the trajectory tracking problem of underactuated surface vessels. Simulation results validate the tracking performance of the proposed controllers. The closed-loop stability is testified by the Lyapunov stability theorem.

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A Compact 3 Degree of Freedom Spherical Joint

Journal of Mechanisms and Robotics ◽

10.1115/1.4004028 ◽

2011 ◽

Vol 3 (3) ◽

Cited By ~ 5

Author(s):

Mark L. Guckert ◽

Michael D. Naish

Keyword(s):

Control Systems ◽

Degrees Of Freedom ◽

Closed Loop ◽

Degree Of Freedom ◽

Robotic Systems ◽

Closed Loop Control ◽

Spherical Joint ◽

Experimental Assessment ◽

Loop Control ◽

Robotic Applications

Spherical joints have evolved into a critical component of many robotic systems, often used to provide dexterity at the wrist of a manipulator. In this work, a novel 3 degree of freedom spherical joint is proposed, actuated by tendons that run along the surface of the sphere. The joint is mechanically simple and avoids mechanical singularities. The kinematics and mechanics of the joint are modeled and used to develop both open- and closed-loop control systems. Simulated and experimental assessment of the joint performance demonstrates that it can be successfully controlled in 3 degrees of freedom. It is expected that the joint will be a useful option in the development of emerging robotic applications, particularly those requiring miniaturization.

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Geometry Control of the Deposited Layer in a Nonplanar Laser Cladding Process Using a Variable Structure Controller

Journal of Manufacturing Science and Engineering ◽

10.1115/1.2823085 ◽

2008 ◽

Vol 130 (3) ◽

Cited By ~ 39

Author(s):

Alireza Fathi ◽

Amir Khajepour ◽

Mohammad Durali ◽

Ehsan Toyserkani

Keyword(s):

Laser Cladding ◽

Closed Loop ◽

Least Squares Method ◽

Sliding Mode ◽

Scanning Speed ◽

Recursive Least Squares ◽

Hammerstein Model ◽

Model Parameters ◽

Control Input ◽

Laser Cladding Process

This paper presents a closed-loop laser cladding process used in nonplanar deposition of desired metallic materials. In the proposed system, the deposited layer geometry is continuously controlled via a sliding mode controller (SMC). The controller, which uses the scanning speed as the control input, is designed based on a parametric Hammerstein model. The model is a parametric dynamic model with several unknown parameters, which are identified experimentally using the recursive least squares method. The designed SMC is robust to all model parameters’ uncertainties and disturbances. The results showed that the tracking accuracy improves and the chattering effect reduces if an integrator on the scanning speed is added to the controller. It was observed that this addition decreases the response speed. The performance of the proposed controllers was verified through the fabrication of several parts made of SS303-L. This verification indicates that the developed closed-loop laser cladding process can reduce stair-step effects as well as production time in rapid prototyping of functional parts created with the adaptive slicing technique.

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Robust Adaptive Controller Design for a Quadrotor Helicopter

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.284-287.2296 ◽

2013 ◽

Vol 284-287 ◽

pp. 2296-2300 ◽

Cited By ~ 3

Author(s):

Kuang Shine Yang ◽

Chi Cheng Cheng

Keyword(s):

Attitude Control ◽

Degrees Of Freedom ◽

Controller Design ◽

Sliding Mode ◽

Underactuated System ◽

Parameter Uncertainties ◽

Unknown Parameters ◽

External Disturbances ◽

Quadrotor Helicopter ◽

Robust Adaptive

The quadrotor helicopter is designed to easily move in particular environments because it can take off and land in limited space and easily hover at a fixed location. For this reason, a robust adaptive sliding mode controller is developed to control of a quadrotor helicopter in the presence of external disturbances and parameter uncertainties. The quadrotor helicopter system is a typical underactuated system, which has fewer independent control actuators than degrees of freedom to be controlled. The main contribution here is to afford simulation and verification for the quadrotor helicopter flight controller under the assumption of unknown parameters. By utilizing the Lyapunov stability theorem, we can achieve asymptotic tracking of desired reference commands for the quadrotor helicopter, which is subject to both external disturbances and parametric uncertainties. From the simulation results, the controller was sufficient to achieve position and attitude control of the quadrotor helicopter system, which permits possible real time applications in the near future.

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A Modified Extended Recursive Least-Squares Method for Closed-Loop Identification of FIR Models

Industrial & Engineering Chemistry Research ◽

10.1021/ie800922w ◽

2009 ◽

Vol 48 (13) ◽

pp. 6327-6338 ◽

Cited By ~ 3

Author(s):

Christopher L. Betts ◽

Srinivas Karra ◽

M. Nazmul Karim ◽

James B. Riggs

Keyword(s):

Least Squares ◽

Closed Loop ◽

Least Squares Method ◽

Recursive Least Squares ◽

Closed Loop Identification ◽

Recursive Least Squares Method

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Design and Application of Chattering-Free Sliding Mode Controller to Cable-Driven Parallel Robot Manipulator: Theory and Experiment

Volume 2: 34th Annual Mechanisms and Robotics Conference, Parts A and B ◽

10.1115/detc2010-29153 ◽

2010 ◽

Cited By ~ 4

Author(s):

Meysar Zeinali ◽

Amir Khajepour

Keyword(s):

High Performance ◽

Degrees Of Freedom ◽

Controller Design ◽

Sliding Mode ◽

Robot Manipulator ◽

Robot Manipulators ◽

Parallel Robot ◽

Industrial Applications ◽

Fast Time ◽

Chattering Free

High-performance robust controller design for nonlinear uncertain dynamical systems such as cable-driven parallel robot manipulators is a challenging work. In this paper, a new and systematic approach to combine sliding mode control, adaptive control design techniques and PID control for tracking control of cable-driven parallel robot manipulators, in the presence of model uncertainties is presented. In the proposed method, structured (parametric) and unstructured (un-modeled) uncertainties are lumped into one term and one uncertain parameter (term) is considered corresponding to each degrees of freedom of robot manipulator. Therefore, the problem of computation burden and large number of parameters, which are not addressed in the literature, is solved to a large extent. The global uniform ultimate boundedness stability is obtained in the presence of fast time-varying uncertainties. The simulation and experimental results revealed that the proposed method is robust against uncertainties and its simplicity makes the approach attractive for industrial applications.

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Autotuning with multiharmonic perturbations. I. Nonparametric closed loop identification

UKACC International Conference on Control (CONTROL '98) ◽

10.1049/cp:19980425 ◽

1998 ◽

Author(s):

P.D. Fox

Keyword(s):

Closed Loop ◽

Closed Loop Identification

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Optimization of sliding mode control with PID surface for robot manipulator by Evolutionary Algorithms

Open Computer Science ◽

10.1515/comp-2020-0144 ◽

2020 ◽

Vol 10 (1) ◽

pp. 396-407

Author(s):

Fatiha Loucif ◽

Sihem Kechida

Keyword(s):

Sliding Mode ◽

Robot Manipulator ◽

Absolute Error ◽

Grey Wolf Optimizer ◽

Optimal Parameters ◽

Error Criterion ◽

Trajectory Tracking Control ◽

Integral Time ◽

Sine Cosine Algorithm ◽

Antlion Optimization

AbstractIn this paper, a sliding mode controller (SMC) with PID surface is designed for the trajectory tracking control of a robot manipulator using different optimization algorithms such as, Antlion Optimization Algorithm (ALO) Sine Cosine Algorithm (SCA) Grey Wolf Optimizer (GWO) and Whale Optimizer Algorithm (WOA). The aim of this work is to introduce a novel SMC-PID-ALO to control nonlinear systems, especially the position of two of the joints of a 2DOF robot manipulator. The basic idea is to determinate four optimal parameters (Kp, Ki, Kd and lamda) ensuring the best performance of a robot manipulator system, minimizing the integral time absolute error criterion (ITAE) and the integral time square error criterion (ISTE). The robot manipulator is modeled in Simulink and the control is implemented using the MATLAB environment. The obtained simulation results prove the robustness of ALO in comparison with other algorithms.

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