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.

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.

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.

Direct measurement of the absolute value of the interaction force between the fiber probe and the sample in a scanning near-field optical microscope

2002 ◽  
Vol 81 (8) ◽  
pp. 1503-1505 ◽  
Author(s):  
D. A. Lapshin ◽  
V. S. Letokhov ◽  
G. T. Shubeita ◽  
S. K. Sekatskii ◽  
G. Dietler
Keyword(s):  
Direct Measurement ◽  
Near Field ◽  
Interaction Force ◽  
Optical Microscope ◽  
Fiber Probe ◽  
Absolute Value ◽  
The Absolute

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.

scholarly journals Adaptive Predefined Performance Neural Control for Robotic Manipulators with Unknown Dead Zone

2020 ◽  
Vol 2020 ◽  
pp. 1-8 ◽  
Author(s):  
Shifen Shao ◽  
Kaisheng Zhang ◽  
Jun Li ◽  
Jirong Wang
Keyword(s):  
Neural Control ◽  
Dead Zone ◽  
Tracking Error ◽  
Transient Behavior ◽  
Robotic Manipulators ◽  
System Stability ◽  
Control Effect ◽  
Tracking Errors ◽  
Control Scheme ◽  
Funnel Control

This paper proposes an adaptive predefined performance neural control scheme for robotic manipulators in the presence of nonlinear dead zone. A neural network (NN) is utilized to estimate the model uncertainties and unknown dynamics. An improved funnel function is designed to guarantee the transient behavior of the tracking error. The proposed funnel function can release the assumption on the conventional funnel control. Then, an adaptive predefined performance neural controller is proposed for robotic manipulators, while the tracking errors fall within a prescribed funnel boundary. The closed-loop system stability is proved via Lyapunov function. Finally, the numerical simulation results based on a 2-DOF robotic manipulator illustrate the control effect of the presented approach.

Asymptotic Impact Control of Hydraulic Actuators With Friction

2004 ◽  
Author(s):  
P. Sekhavat ◽  
N. Sepehri ◽  
Q. Wu
Keyword(s):  
Steady State ◽  
Nonlinear Control ◽  
Dry Friction ◽  
Position Control ◽  
Past Research ◽  
Hydraulic Actuator ◽  
Stick Slip ◽  
Hydraulic Actuators ◽  
Control Scheme ◽  
Control Schemes

The focus of this work is stabilization of hydraulic actuators during the transition from free motion to constraint motion and regulating the intermediate impacts that could drive the system unstable. In our past research, we introduced Lyapunov-based nonlinear control schemes capable of fulfilling the above goal by resting the implement on the surface of the environment before starting the sustained-contact motion. The hydraulic actuator’s stick-slip friction effect was, however, either not included in the analysis or not compensated by the control action. In this paper, the application of our previously introduced friction compensating position control scheme is extended to impact regulation of a hydraulic actuator. Theoretical solution and stability analyses as well as actual experiments prove that such control scheme is also effective for asymptotic impact control (with no position steady-state error) of hydraulic actuators in the presence of actuator’s dry friction.

scholarly journals Iterative learning of human partner’s desired trajectory for proactive human–robot collaboration

2020 ◽  
Vol 4 (2) ◽  
pp. 229-242
Author(s):  
Jingkang Xia ◽  
Deqing Huang ◽  
Yanan Li ◽  
Na Qin
Keyword(s):  
Learning Algorithm ◽  
Interaction Force ◽  
Iterative Learning ◽  
Reference Trajectory ◽  
Robot Controller ◽  
Task Period ◽  
Human Partner ◽  
Control Scheme ◽  
Control Objective ◽  
Human Robot Collaboration

Abstract A period-varying iterative learning control scheme is proposed for a robotic manipulator to learn a target trajectory that is planned by a human partner but unknown to the robot, which is a typical scenario in many applications. The proposed method updates the robot’s reference trajectory in an iterative manner to minimize the interaction force applied by the human. Although a repetitive human–robot collaboration task is considered, the task period is subject to uncertainty introduced by the human. To address this issue, a novel learning mechanism is proposed to achieve the control objective. Theoretical analysis is performed to prove the performance of the learning algorithm and robot controller. Selective simulations and experiments on a robotic arm are carried out to show the effectiveness of the proposed method in human–robot collaboration.

Sign in / Sign up

Export Citation Format

Share Document