scholarly journals Robust Controller for Pursuing Trajectory and Force Estimations of a Bilateral Tele-Operated Hydraulic Manipulator

2021 ◽  
Vol 13 (9) ◽  
pp. 1648
Author(s):  
Karam Dad Kallu ◽  
Amad Zafar ◽  
Muhammad Umair Ali ◽  
Shahzad Ahmed ◽  
Min Cheol Lee
Keyword(s):  
Sliding Mode ◽  
Reaction Force ◽  
Force Estimation ◽  
Physical Force ◽  
Robust Controller ◽  
Terminal Sliding Mode ◽  
Impedance Model ◽  
Remote Environment ◽  
Operation Control ◽  
Hydraulic Manipulator

In hazardous/emergency situations, public safety is of the utmost concern. In areas where human access is not possible or is restricted due to hazardous situations, a system or robot that can be distantly controlled is mandatory. There are many applications in which force cannot be applied directly while using physical sensors. Therefore, in this research, a robust controller for pursuing trajectory and force estimations while deprived of any signals or sensors for bilateral tele-operation of a hydraulic manipulator is suggested to handle these hazardous, emergency circumstances. A terminal sliding control with a sliding perturbation observer (TSMCSPO) is considered as the robust controller for a coupled leader and hydraulic follower system. The ultimate use of this controller is as a sliding perturbation observer (SPO) that can estimate the reaction force without any physical force sensors. Robust and perfect position tracking is attained with terminal sliding mode control (TSMC) in addition to control of the hydraulic follower manipulator. The force estimation and pursuing trajectory for the leader–follower system is built upon a bilateral tele-operation control approach. The difference between the reaction forces (caused by the remote environment) and the operating forces (applied by the human operator) required the involvement of an impedance model. The impedance model is implemented in the leader manipulator to provide human operators with an actual sense of the reaction force while the manipulator connects with the remote environment. A camera is used to ensure the safety of the workplace through visual feedback. The experimental results showed that the controller was robust at pursuing trajectory and force estimations for the bilateral tele-operation control of a hydraulic manipulator.

Sliding Perturbation Observer Based Reaction Force Estimation Method of Surgical Robot Instrument for Haptic Realization

2015 ◽  
Vol 12 (02) ◽  
pp. 1550013 ◽  
Author(s):  
Sung Min Yoon ◽  
Min Cheol Lee ◽  
Chi Yen Kim
Keyword(s):  
Coulomb Friction ◽  
Sliding Mode ◽  
Reaction Force ◽  
Estimation Method ◽  
Surgical Robot ◽  
Model Parameters ◽  
Force Estimation ◽  
Haptic Information ◽  
Robust Controller ◽  
Practice Time

Previous research applied sliding mode control with a sliding perturbation observer (SMCSPO) algorithm as a robust controller to control a surgical robotic instrument and reported that reaction force loaded on the tip can be estimated similarly by the sliding perturbation observer (SPO). However, some factors, such as friction, in which it is difficult to find the model parameters beforehand, can have an effect on the reaction force estimation because the factors are included in the estimated perturbation. This paper addresses the SPO based reaction force estimation method to extract a pure reaction force on a surgical robot instrument in the case of including Coulomb friction due to the operation of cable-pulley structure. Coulomb friction can be estimated experimentally and compensated for from the estimated perturbation. An experimental evaluation was performed to prove the suggested estimation method. The results show that SPO can be substituted for sensors to measure the reaction force. This estimated reaction force will be used to realize the haptic function by sending the reaction force to a master device for a surgeon. The results will help to create surgical benefit such as shortening the practice time of a surgeon and providing haptic information to the surgeon by using it as haptic signal to protect an organ by forming a force boundary.

scholarly journals Estimated Reaction Force-Based Bilateral Control between 3DOF Master and Hydraulic Slave Manipulators for Dismantlement

Electronics ◽  
2018 ◽  
Vol 7 (10) ◽  
pp. 256 ◽  
Author(s):  
Karam Kallu ◽  
Jie Wang ◽  
Saad Abbasi ◽  
Min Lee
Keyword(s):  
Sliding Mode Control ◽  
Control Strategy ◽  
Sliding Mode ◽  
Reaction Force ◽  
Servo System ◽  
Degree Of Freedom ◽  
Bilateral Control ◽  
Impedance Model ◽  
Hydraulic Servo ◽  
Hydraulic Servo System

This paper proposes a novel bilateral control design based on an estimated reaction force without a force sensor for a three-degree of freedom hydraulic servo system with master–slave manipulators. The proposed method is based upon sliding mode control with sliding perturbation observer (SMCSPO) using a bilateral control environment. The sliding perturbation observer (SPO) estimates the reaction force at the end effector and second link without using any sensors. The sliding mode control (SMC) is used as a bilateral controller for the robust position tracking and control of the slave device. A bilateral control strategy in a hydraulic servo system provides robust position and force tracking between master and slave. The difference between the reaction force of the slave produced by the effect of the remote environment and the operating force applied to the master by the operator is expressed in the target impedance model. The impedance model is applied to the master and allows the operator to feel the reaction force from the environment. This research experimentally verifies that the slave device can follow the trajectory of the master device using the proposed bilateral control strategy based on the estimated reaction force. This technique will be convenient for three or more degree of freedom (DOF) hydraulic servo systems used in dismantling nuclear power plants. It is worthy to mention that a camera is used for visual feedback on the safety of the environment and workspace.

scholarly journals Robust attitude tracking control scheme for a multi-body spacecraft using a radial basis function network and terminal sliding mode

2014 ◽  
Vol 24 (5) ◽  
Author(s):  
CHANGQING YUAN ◽  
YANHUA ZHONG ◽  
JINGRUI ZHANG ◽  
HONGBUO LI ◽  
GUOJUN YANG ◽  
...  
Keyword(s):  
Basis Function ◽  
Sliding Mode ◽  
Radial Basis Function Network ◽  
Robust Controller ◽  
External Disturbances ◽  
Terminal Sliding Mode ◽  
Attitude Tracking ◽  
Control Scheme ◽  
Multi Body ◽  
Function Network

We present a novel robust control scheme that deals with multi-body spacecraft attitude tracking problems. The control scheme consists of a radial basis function network (RBFN) and a robust controller. By using the finite time convergence property of the terminal sliding mode (TSM), we derive a new online learning algorithm for updating all the parameters of the RBFN that ensures the RBFN has fast approximation for the parameter uncertainties and external disturbances. We design a robust controller to compensate RBFN approximation errors and realise the anticipative stability and performance properties. We can also achieve closed-loop system stability using Lyapunov stability theory.No detailed knowledge of the non-linear dynamics of the spacecraft is required at any point in the entire design process, and the proposed robust scheme is simple and effective and can be applied to more complex systems. Simulation results demonstrate the good tracking characteristics of the proposed control scheme in the presence of inertial uncertainties and external disturbances.

scholarly journals Tele-Operated Bilateral Control of Hydraulic Manipulator Using a Robust Controller Based on the Sensorless Estimated Reaction Force

2019 ◽  
Vol 9 (10) ◽  
pp. 1995 ◽  
Author(s):  
Karam Dad Kallu ◽  
Saad Jamshed Abbasi ◽  
Hamza Khan ◽  
Jie Wang ◽  
Min Cheol Lee
Keyword(s):  
Sliding Mode Control ◽  
Control Strategy ◽  
Nuclear Power ◽  
Power Plants ◽  
Sliding Mode ◽  
Reaction Force ◽  
Life Time ◽  
Bilateral Control ◽  
Mode Control ◽  
Remote Environment

In nuclear power plants (NPP), dismantling is the most technically involved process during their life time. During the dismantling process, public safety must be ensured. In crisis situations, a remotely controlled robot system is needed for the dismantling of NPP. Therefore, in this research, a bilateral tele-operation system is proposed to tackle these emergency conditions. Transparency can be improved by using force and position signal in the control strategy. In some applications, force cannot be determine directly using physical sensors. In this work, a novel tele-operated bilateral control strategy is proposed to estimate the reaction force of 3-degree-of-freedom (DOF) master and hydraulic slave manipulators without the use of a sensor. The control strategy is developed by using sliding mode control with sliding perturbation observer (SMCSPO). The sliding perturbation observer (SPO) estimates the reaction force at the end effector and second link without using sensors. The sliding mode control (SMC) is used as a tele-operated bilateral controller for the robust position tracking and control of the slave device. The impedance model is used to differentiate between the applied force (force exerted by operator) and the reaction force due to the remote environment. Different experiments were performed to verify the proposed strategy. The results indicate that the slave manipulator exactly follows the trajectory of the master device. A camera is used to take visual feedback of the workspace for safety purpose. This technique can also be applied for higher-order DOF manipulators in NPP.

A New Nonsingular Terminal Sliding Mode Control for Rigid Spacecraft Attitude Tracking

2017 ◽  
Vol 140 (5) ◽  
Author(s):  
Zeng Wang ◽  
Yuxin Su ◽  
Liyin Zhang
Keyword(s):  
Equilibrium Point ◽  
Finite Time ◽  
Sliding Mode ◽  
Tracking Errors ◽  
Robust Controller ◽  
External Disturbances ◽  
Terminal Sliding Mode ◽  
Nonsingular Terminal Sliding Mode ◽  
Attitude Tracking ◽  
Rigid Spacecraft

This paper addresses the finite time attitude tracking for rigid spacecraft with inertia uncertainties and external disturbances. First, a new nonsingular terminal sliding mode (NTSM) surface is proposed for singularity elimination. Second, a robust controller based on NTSM is designed to solve the attitude tracking problem. It is proved that the new NTSM can converge to zero within finite time, and the attitude tracking errors converge to an arbitrary small bound centered on equilibrium point within finite time and then go to equilibrium point asymptotically. The appealing features of the proposed control are fast convergence, high precision, strong robustness, and easy implementation. Simulations verify the effectiveness of the proposed approach.

Adaptive Wave Neural Network Nonsingular Terminal Sliding Mode Control for an Underwater Manipulator with Force Estimation

2020 ◽  
Author(s):  
Lijun Han ◽  
Guoyuan Tang ◽  
Zengcheng Zhou ◽  
Hui Huang ◽  
De Xie
Keyword(s):  
Neural Network ◽  
Sliding Mode Control ◽  
Sliding Mode ◽  
Estimation Method ◽  
Terminal Sliding Mode Control ◽  
Force Estimation ◽  
Terminal Sliding Mode ◽  
Mode Control ◽  
Nonsingular Terminal Sliding Mode ◽  
Underwater Manipulator

This paper proposes an adaptive wave neural network nonsingular terminal sliding mode control (AWNN-NTSMC) strategy with force estimation, which is exploited to address the path tracking control problem of the underwater manipulator under lumped disturbances. The proposed control scheme contains three parts: a nonsingular terminal sliding mode surface (NTSMS) part, an AWNN part and a force estimation part. The NTSMS is designed to make the system states achieve fast convergence in the sliding mode phase. The AWNN theory is utilized to approximate the lumped disturbances via on-line adjustment of the network parameters. The force estimation method is applied in compensating the effect of external force on the control system. Besides, a saturated function instead of the signum function is used aiming to the chattering suppression. Asymptotic stability of the closed-loop system is guaranteed by the Lyapunov stability. Finally, by using a six degree of freedom (DOF) underwater manipulator, comparative simulation results validate the better tracking performance and stronger robustness against disturbances of our proposed scheme.

Robust position control of hydraulic manipulators using time delay estimation and nonsingular fast terminal sliding mode

2017 ◽  
Vol 232 (1) ◽  
pp. 50-61 ◽  
Author(s):  
Xichang Liang ◽  
Yi Wan ◽  
Chengrui Zhang ◽  
Yanyun Kou ◽  
Qianqian Xin ◽  
...  
Keyword(s):  
Time Delay ◽  
Position Control ◽  
Sliding Mode ◽  
Time Delay Estimation ◽  
Tracking Performance ◽  
Delay Estimation ◽  
Terminal Sliding Mode ◽  
Model Free ◽  
Fast Terminal Sliding Mode ◽  
Hydraulic Manipulator

A simple and robust tracking controller based on time delay estimation and nonsingular fast terminal sliding mode is proposed for the position control of hydraulic manipulator. The proposed controller does not require the mathematical model of hydraulic manipulator dynamics, which ensures that the method is simple and model free. Two elements, time delay estimation and nonsingular fast terminal sliding mode, are implemented in the proposed controller. Time delay estimation estimates the complex dynamics of the hydraulic manipulator, and nonsingular fast terminal sliding mode is implemented as the nonlinear desired error dynamic to ensure fast convergence and high trajectory tracking accuracy. Experiments are performed to verify the tracking performance of the method on a hydraulic manipulator. The results demonstrate that this method achieves faster and higher precision position tracking performance than a conventional time delay control with linear error dynamics.

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