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 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 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.

scholarly journals Experimental Evaluation on Haptic Feedback Accuracy by Using Two Self-Made Haptic Devices and One Additional Interface in Robotic Teleoperation

Actuators ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 24
Author(s):  
Guan-Yang Liu ◽  
Yi Wang ◽  
Chao Huang ◽  
Chen Guan ◽  
Dong-Tao Ma ◽  
...  
Keyword(s):  
Experimental Evaluation ◽  
Haptic Feedback ◽  
Force Sensor ◽  
Interaction Force ◽  
Haptic Device ◽  
Human Hand ◽  
Haptic Devices ◽  
Input Noise ◽  
Output Force ◽  
Robotic Teleoperation

The goal of haptic feedback in robotic teleoperation is to enable users to accurately feel the interaction force measured at the slave side and precisely understand what is happening in the slave environment. The accuracy of the feedback force describing the error between the actual feedback force felt by a user at the master side and the measured interaction force at the slave side is the key performance indicator for haptic display in robotic teleoperation. In this paper, we evaluate the haptic feedback accuracy in robotic teleoperation via experimental method. A special interface iHandle and two haptic devices, iGrasp-T and iGrasp-R, designed for robotic teleoperation are developed for experimental evaluation. The device iHandle integrates a high-performance force sensor and a micro attitude and heading reference system which can be used to identify human upper limb motor abilities, such as posture maintenance and force application. When a user is asked to grasp the iHandle and maintain a fixed position and posture, the fluctuation value of hand posture is measured to be between 2 and 8 degrees. Based on the experimental results, human hand tremble as input noise sensed by the haptic device is found to be a major reason that results in the noise of output force from haptic device if the spring-damping model is used to render feedback force. Therefore, haptic rendering algorithms should be independent of hand motion information to avoid input noise from human hand to the haptic control loop in teleoperation. Moreover, the iHandle can be fixed at the end effector of haptic devices; iGrasp-T or iGrasp-R, to measure the output force/torque from iGrasp-T or iGrasp-Rand to the user. Experimental results show that the accuracy of the output force from haptic device iGrasp-T is approximately 0.92 N, and using the force sensor in the iHandle can compensate for the output force inaccuracy of device iGrasp-T to 0.1 N. Using a force sensor as the feedback link to form a closed-loop feedback force control system is an effective way to improve the accuracy of feedback force and guarantee high-fidelity of feedback forces at the master side in robotic teleoperation.

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

Miniaturized Cutting Tool With Triaxial Force Sensing Capabilities for Minimally Invasive Surgery

2007 ◽  
Vol 1 (3) ◽  
pp. 206-211 ◽  
Author(s):  
Pietro Valdastri ◽  
Keith Houston ◽  
Arianna Menciassi ◽  
Paolo Dario ◽  
Arne Sieber ◽  
...  
Keyword(s):  
Minimally Invasive ◽  
Cutting Tool ◽  
Haptic Feedback ◽  
Ex Vivo ◽  
Force Sensor ◽  
Outer Diameter ◽  
Muscular Tissue ◽  
Force Output ◽  
Force Range ◽  
Minimally Invasive Robotic Surgery

This paper reports a miniaturized triaxial force sensorized cutting tool for minimally invasive robotic surgery. This device exploits a silicon-based microelectromechanical system triaxial force sensor that acts as the core component of the system. The outer diameter of the proposed device is less than 3mm, thus enabling the insertion through a 9 French catheter guide. Characterization tests are performed for both normal and tangential loadings. A linear transformation relating the sensor output to the external applied force is introduced in order to have a triaxial force output in real time. Normal force resolution is 8.2bits over a force range between 0N and 30N, while tangential resolution is 7 bits over a range of 5N. Force signals with frequencies up to 250Hz can successfully be detected, enabling haptic feedback and tissue mechanical properties investigation. Preliminary ex vivo muscular tissue cutting experiments are introduced and discussed in order to evaluate the device overall performances.

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.

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 Haptic Glove Using Tendon-Driven Soft Robotic Mechanism

2020 ◽  
Vol 8 ◽  
Author(s):  
Siyeon Baik ◽  
Shinsuk Park ◽  
Jaeyoung Park
Keyword(s):  
Haptic Feedback ◽  
Human Perception ◽  
Force Sensor ◽  
Experimental Result ◽  
Force Distribution ◽  
Distribution Method ◽  
Force Perception ◽  
Cutaneous Feedback ◽  
Significant Difference ◽  
Kinesthetic Feedback

Recent advancements in virtual reality and augmented reality call for light-weight and compliant haptic interfaces to maximize the task-performance interactivity with the virtual or extended environment. Noting this, we propose a haptic glove using a tendon-driven compliant robotic mechanism. Our proposed interface can provide haptic feedback to two fingers of a user, an index finger and a thumb. It can provide both cutaneous and kinesthetic feedback to the fingers by using the tendon-driven system. Each actuator is paired with a force sensor to exert the desired tension accurately. In order to optimize the perception of the kinesthetic feedback, we propose a perception-based kinesthetic feedback distribution strategy. We experimentally measured the force perception weight for peripheral interphalangeal (PIP) and metacarpophalangeal (MCP) joints. We observed no significant difference in the force perception between the two joints. Then, based on the obtained weights, our proposed force distribution method calculates the force for each joint. We also evaluated the effect of additional cutaneous feedback to the kinesthetic feedback, on the force perception at the fingertip. The experimental result has shown that additional cutaneous feedback has significantly increased the sensitivity of the human perception. Finally, we evaluated our proposed system and force distribution algorithm by conducting a human subject test. The experimental result indicates that the availability of the cutaneous feedback significantly improved the perceived realism and acuity of the contact force.

Design and Analysis of a Multimodal Grasper Having Shape Conformity and Within-Hand Manipulation With Adjustable Contact Forces

2019 ◽  
Vol 11 (5) ◽  
Author(s):  
Nagamanikandan Govindan ◽  
Asokan Thondiyath
Keyword(s):  
Control Strategies ◽  
Low Cost ◽  
Active Surface ◽  
Force Sensor ◽  
Contact Forces ◽  
Geometrical Shape ◽  
Planning And Control ◽  
Control Scheme ◽  
And Control ◽  
Compact Mechanism

Abstract This paper presents the design, analysis, and testing of a novel multimodal grasper having the capabilities of shape conformation, within-hand manipulation, and a built-in compact mechanism to vary the forces at the contact surface. The proposed grasper has two important qualities: versatility and less complexity. The former refers to the ability to grasp a range of objects having different geometrical shape, size, and payload and perform in-hand manipulations such as rolling and sliding, and the latter refers to the uncomplicated design, and ease of planning and control strategies. Increasing the number of functions performed by the grasper to adapt to a variety of tasks in structured and unstructured environments without increasing the mechanical complexity is the main interest of this research. The proposed grasper consists of two hybrid jaws having a rigid inner structure encompassed by a flexible, active gripping surface. The flexibility of the active surface has been exploited to achieve shape conformation, and the same has been utilized with a compact mechanism, introduced in the jaws, to vary the contact forces while grasping and manipulating an object. Simple and scalable structure, compactness, low cost, and simple control scheme are the main features of the proposed design. Detailed kinematic and static analysis are presented to show the capability of the grasper to adjust and estimate the contact forces without using a force sensor. Experiments are conducted on the fabricated prototype to validate the different modes of operation and to evaluate the advantages of the proposed concept.

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