A Hybrid Haptic Sensation for Teleoperation of Hydraulic Manipulators

2015 ◽  
Vol 137 (9) ◽  
Author(s):  
Kourosh Zareinia ◽  
Nariman Sepehri
Keyword(s):  
Force Feedback ◽  
Experimental Studies ◽  
Interaction Force ◽  
Position Tracking ◽  
Hydraulic Actuator ◽  
Hydraulic Manipulators ◽  
Nonsmooth Systems ◽  
Control Scheme ◽  
The Stability ◽  
Haptic Sensation

In this paper, a control scheme is designed for stable haptic teleoperation of hydraulic manipulators. The controller results in a stable position tracking for the hydraulic actuator (slave) in both unconstrained and constrained motions. The force feedback at the haptic (master) side is a combination of two different sensations. For free motion, the haptic device provides a haptic force based on the position error between the displacements of the master and the slave. The force also serves to alert the operator when the slave is ahead or behind in position tracking of the master. Once the slave comes in contact with the environment, the haptic force is augmented by the interaction force. The uniqueness, continuation, and existence of the Filippov solution to this system with the discontinuity surfaces are proven first. The extension of Lyapunov's stability theory to nonsmooth systems is then employed to prove the stability by constructing a Lyapunov function. The effectiveness of the controller is validated via experimental studies. It is shown that while stable, the system performs well in terms of position tracking of the hydraulic actuator and providing a haptic feel to the operator. The measurements required by the controller are supply pressure, actuator's line pressures, interaction force, and displacements of the master and slave.

A Lyapunov Stable Controller for Bilateral Haptic Teleoperation of Single-Rod Hydraulic Actuators

2017 ◽  
Vol 139 (11) ◽  
Author(s):  
Vikram Banthia ◽  
Kourosh Zareinia ◽  
Subramaniam Balakrishnan ◽  
Nariman Sepehri
Keyword(s):  
Direct Measurement ◽  
Haptic Feedback ◽  
Force Sensor ◽  
Interaction Force ◽  
Task Environment ◽  
Hydraulic Actuator ◽  
Hydraulic Manipulators ◽  
Position Errors ◽  
Control Scheme ◽  
Stable Control

A Lyapunov stable control scheme is designed and implemented for bilateral haptic teleoperation of a single-rod hydraulic actuator. The proposed controller is capable of reducing position errors at master and slave sides, as well as perceiving the interaction force between the actuator and the task environment without a need for direct measurement of force. The controller only requires the actuator's line pressures and displacements of the master and slave. Stability of the proposed controller incorporating hydraulic nonlinearities and operator dynamics is analytically proven. Simulation studies demonstrate that the proposed system can reach an equilibrium point while interacting with an environment exhibiting stiffness. Experimental results confirm that the controller is able to effectively maintain stability, while having good position tracking by the hydraulic actuator as well as perceiving the contact force between the actuator and the task environment without direct measurement. This kind of haptic feedback force is a suitable choice for applications where mounting a force sensor at the end-effector is not feasible, such as excavators and backhoes. This work contributes to enhancing the operator's ability to perform stable haptic-enabled teleoperation of hydraulic manipulators.

Coupled Stability of Multiport Systems—Theory and Experiments

1994 ◽  
Vol 116 (3) ◽  
pp. 419-428 ◽  
Author(s):  
J. E. Colgate
Keyword(s):  
Stability Property ◽  
Force Feedback ◽  
Linear Time ◽  
Experimental Studies ◽  
Sufficient Conditions ◽  
Direct Drive ◽  
Property A ◽  
Linear Time Invariant ◽  
The Stability ◽  
Necessary And Sufficient

This paper presents both theoretical and experimental studies of the stability of dynamic interaction between a feedback controlled manipulator and a passive environment. Necessary and sufficient conditions for “coupled stability”—the stability of a linear, time-invariant n-port (e.g., a robot, linearized about an operating point) coupled to a passive, but otherwise arbitrary, environment—are presented. The problem of assessing coupled stability for a physical system (continuous time) with a discrete time controller is then addressed. It is demonstrated that such a system may exhibit the coupled stability property; however, analytical, or even inexpensive numerical conditions are difficult to obtain. Therefore, an approximate condition, based on easily computed multivariable Nyquist plots, is developed. This condition is used to analyze two controllers implemented on a two-link, direct drive robot. An impedance controller demonstrates that a feedback controlled manipulator may satisfy the coupled stability property. A LQG/LTR controller illustrates specific consequences of failure to meet the coupled stability criterion; it also illustrates how coupled instability may arise in the absence of force feedback. Two experimental procedures—measurement of endpoint admittance and interaction with springs and masses—are introduced and used to evaluate the above controllers. Theoretical and experimental results are compared.

Position-Mode Haptic-Based Control of Teleoperated Hydraulic Actuators

2011 ◽  
Author(s):  
Kurosh Zarei-nia ◽  
Nariman Sepehri
Keyword(s):  
Invariant Set ◽  
Haptic Device ◽  
Position Tracking ◽  
Good Position ◽  
View Point ◽  
Hydraulic Actuator ◽  
Control Laws ◽  
Hydraulic Actuators ◽  
Control Scheme ◽  
On Line

A control scheme for teleoperation of hydraulic actuators, using a haptic device, is developed and experimentally evaluated in this paper. In the control laws, the position error between the displacement of the haptic device and the hydraulic actuator movement is used at both master and slave sides to maintain good position tracking at the actuator side while providing a haptic force to the operator. Lyapunov’s stability theory and LaSalle’s invariant set theorems are employed to prove the asymptotic stability of the system. It is shown that beside stability, the system performs well in terms of position tracking of the hydraulic actuator and providing a feel of telepresence to the operator. Proposed controller only needs system’s pressures and displacements that are easy to obtain via on-line measurements. Additionally, the controller does not need any information about the parameters of the system. These characteristics make the controller very attractive from the implementation view point.

A force reflecting control scheme for telemanipulators with high reduction ratio joint

Robotica ◽  
2002 ◽  
Vol 20 (1) ◽  
pp. 69-79 ◽  
Author(s):  
Sung-Ho Ahn ◽  
Ji-Sup Yoon ◽  
Sang-Jeong Lee
Keyword(s):  
Input Saturation ◽  
High Ratio ◽  
Reduction Ratio ◽  
Tracking Performance ◽  
Position Tracking ◽  
Control Input ◽  
Slow Dynamics ◽  
Control Scheme ◽  
High Reduction ◽  
The Stability

Since a slave manipulator with a high reduction ratio joint generally has slow dynamics in comparison with a master manipulator in telemanipulation systems, its control input is likely to be saturated resulting in poor position tracking performance and deteriorated stability. This paper proposes a force reflecting control scheme for telemanipulators with a high reduction ratio joint, which can effectively compensate the control input saturation caused by the high ratio gear reducer at its joint. The proposed scheme is also shown to guarantee the stability and provides an excellent position tracking performance regardless of the saturation.

Experimental Evaluation of Two Bilateral Control Schemes Applied to a Tele-Operated Hydraulic Actuator

2009 ◽  
Author(s):  
Kurosh Zarei-nia ◽  
Amin Yazdanpanah Goharrizi ◽  
Nariman Sepehri ◽  
Wai-keung Fung
Keyword(s):  
Force Feedback ◽  
Sensory Information ◽  
Future Research ◽  
Bilateral Control ◽  
Hydraulic Actuator ◽  
The Road ◽  
Hydraulic Manipulators ◽  
Control Schemes ◽  
Electrically Actuated ◽  
Research On Application

Providing force feedback along with other sensory information can greatly increase task quality, productivity, and safety during teleoperation of hydraulic manipulators. However, as compared to the class of electrically-actuated robots, research on application of bilateral control schemes applied to the class of hydraulic manipulators is sparse. In this paper, we present experimental results of implementing two bilateral control scheme, previously developed for electrically-actuated manipulators, to a hydraulic actuator having additional nonlinear dynamics. The two schemes chosen are ‘force reflection’ and ‘position error’. The performance of each scheme is evaluated in terms of position tracking, force tracking, and fidelity of perceived stiffness by the human operator. The results reveal specific features of each scheme paving the road for future research in this direction in terms of designing appropriate bilateral control schemes for hydraulic manipulators.

PD-like controller with impedance for delayed bilateral teleoperation of mobile robots

Robotica ◽  
2015 ◽  
Vol 34 (9) ◽  
pp. 2151-2161 ◽  
Author(s):  
E. Slawiñski ◽  
S. García ◽  
L. Salinas ◽  
V. Mut
Keyword(s):  
Mobile Robot ◽  
Mobile Robots ◽  
Force Feedback ◽  
Robot Motion ◽  
Time Varying ◽  
Control Parameters ◽  
Bilateral Teleoperation ◽  
Teleoperation System ◽  
Control Scheme ◽  
The Stability

SUMMARYThis paper proposes a control scheme applied to the delayed bilateral teleoperation of mobile robots with force feedback in face of asymmetric and time-varying delays. The scheme is managed by a velocity PD-like control plus impedance and a force feedback based on damping and synchronization error. A fictitious force, depending on the robot motion and its environment, is used to avoid possible collisions. In addition, the stability of the system is analyzed from which simple conditions for the control parameters are established in order to assure stability. Finally, the performance of the delayed teleoperation system is shown through experiments where a human operator drives a mobile robot.

A Lyapunov Stable Controller for Bilateral Haptic Teleoperation of Single-Rod Hydraulic Actuators Subjected to Base Disturbance

2018 ◽  
Vol 141 (3) ◽  
Author(s):  
Vikram Banthia ◽  
Ali Maddahi ◽  
Kourosh Zareinia ◽  
Subramaniam Balakrishnan ◽  
Nariman Sepehri
Keyword(s):  
Direct Measurement ◽  
Interaction Force ◽  
Base Point ◽  
System Stability ◽  
Task Environment ◽  
Physical Parameters ◽  
Hydraulic Actuator ◽  
Position Errors ◽  
Control Scheme ◽  
Base Disturbance

In this paper, a control scheme is developed and evaluated for stable bilateral haptic teleoperation of a single-rod hydraulic actuator subjected to base disturbance. The proposed controller, based on Lyapunov stability technique, is capable of reducing position errors at master and slave sides, and provides a feel of the contact force between the actuator and the task environment to the operator without a need for direct measurement. The controller requires only the measurements of the actuator line pressures and displacements of the master and slave. The system stability is insensitive to the uncertainties of the physical parameters and of the measurement of the base point motion. Stability of the proposed controller incorporating hydraulic nonlinearities and operator dynamics with an estimated upper value for the base disturbance is analytically proven. Simulation studies validate that the proposed control system is stable while interacting with a task environment. Experimental results demonstrate the effectiveness of control scheme in maintaining stability, while having good position tracking by the hydraulic actuator as well as providing a haptic feel to the operator without direct measurement of interaction force, while the hydraulic actuator is subjected to base disturbance.

scholarly journals Delayed Bilateral Teleoperation of Wheeled Robots including a Command Metric

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Franco Penizzotto ◽  
Sebastian García ◽  
Emanuel Slawiñski ◽  
Vicente Mut
Keyword(s):  
Mobile Robot ◽  
System Architecture ◽  
Communication Channel ◽  
Force Feedback ◽  
Time Varying ◽  
Bilateral Teleoperation ◽  
Wheeled Robots ◽  
Teleoperation System ◽  
Control Scheme ◽  
The Stability

This paper proposes a control scheme applied to the delayed bilateral teleoperation of wheeled robots with force feedback, considering the performance of the operator’s command execution. In addition, the stability of the system is analyzed taking into account the dynamic model of the master as well as the remote mobile robot under asymmetric and time-varying delays of the communication channel. Besides, the performance of the teleoperation system, where a human operator drives a 3D simulator of a wheeled dynamic robot, is evaluated. In addition, we present an experiment where a robot Pioneer is teleoperated, based on the system architecture proposed.

Design of a Nonlinear Position Regulator for Cooperating Hydraulic Manipulators Handling a Rigid Object

2004 ◽  
Author(s):  
Hairong Zeng ◽  
Nariman Sepehri
Keyword(s):  
Control System ◽  
Steady State ◽  
Stability Analysis ◽  
Rigid Object ◽  
Hydraulic Manipulators ◽  
Control Scheme ◽  
Lyapunov’S Second Method ◽  
On Line ◽  
Internal Forces ◽  
The Stability

In this paper, a nonlinear control scheme is developed for performing a cooperative task by hydraulic manipulators. The goal is to design a controller that allows two or more hydraulic robots to coordinately regulate an object’s position/orientation while maintaining desired internal forces on the object and sharing load. First the dynamic model of the whole system, including hydraulic functions, is derived. Then, a controller is designed, augmented by an on-line updating law to eliminate the steady-state error due to lack of knowledge about the weight of the object. Extended Lyapunov’s second method is used for stability analysis of the control system. The stability of the system is guaranteed by constructing a smooth Lyapunov function. Simulations are performed to substantiate the controller developed.

scholarly journals Stability and Transparency of Delayed Bilateral Teleoperation with Haptic Feedback

2019 ◽  
Vol 29 (4) ◽  
pp. 681-692 ◽  
Author(s):  
Edgar Estrada ◽  
Wen Yu ◽  
Xiaoou Li
Keyword(s):  
Force Feedback ◽  
Haptic Feedback ◽  
Human Operator ◽  
Delay Systems ◽  
Bilateral Teleoperation ◽  
Haptic Guidance ◽  
Control Scheme ◽  
The Stability ◽  
Teleoperation Systems ◽  
Whole Systems

Abstract Haptic guidance can improve control accuracy in bilateral teleoperation. With haptic sensing, the human operator feels that he grabs the robot on the remote side. There are results on the stability and transparency analysis of teleoperation without haptic guidance, and the analysis of teleoperation with haptic feedback is only for linear and zero time-delay systems. In this paper, we consider more general cases: the bilateral teleoperation systems have time-varying communication delays, the whole systems are nonlinear, and they have force feedback. By using the admittance human operator model, we propose a new control scheme with the interaction passivity of the teleoperator. The stability and transparency of the master-slave system are proven with the Lyapunov–Krasovskii method. Numerical simulations illustrate the efficiency of the proposed control methods.

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