Haptic Feedback Applied to Pneumatic Walking

2008 ◽  
Author(s):  
Brian Guerriero ◽  
Wayne Book
Keyword(s):  
Force Control ◽  
Force Feedback ◽  
Haptic Feedback ◽  
Control Method ◽  
Position Tracking ◽  
Bilateral Teleoperation ◽  
Pneumatic Actuators ◽  
Position Controller ◽  
Pressure Feedback ◽  
Foot Position

This paper presents a proposed control method for controlling the foot positions of two robotic legs through direct operator inputs with haptic feedback. The robot consists of two 3-DoF legs driven by pneumatic actuators. A demonstration of the controller shows the tracking performance enhancements of the proposed force-based position controller over a simple differential pressure gain scheduler-based position controller. The proposed controller incorporates pressure feedback to create supplementary force control. Foot position tracking remains within 10% of the commanded reference position, even through the sharp disparities of loading conditions as the actuators are either lifting the weight of the legs or supporting the weight of the robot itself. An operator gives direct foot position commands to the controller through two PHANToM haptic devices. Bilateral teleoperation of the system provides directional force feedback to the operator as a function of foot position error. The proposed controller also decreases the ambient and false forces reflected to the operator while moving the legs through gait cycles.

scholarly journals Aerial Tele-Manipulation with Passive Tool via Parallel Position/Force Control

2021 ◽  
Vol 11 (19) ◽  
pp. 8955
Author(s):  
Mostafa Mohammadi ◽  
Davide Bicego ◽  
Antonio Franchi ◽  
Davide Barcelli ◽  
Domenico Prattichizzo
Keyword(s):  
Contact Interaction ◽  
Force Control ◽  
Degrees Of Freedom ◽  
Haptic Feedback ◽  
Situational Awareness ◽  
Control Method ◽  
Bilateral Teleoperation ◽  
Compliant Structure ◽  
Rotational Degrees Of Freedom ◽  
Remote Sites

This paper addresses the problem of unilateral contact interaction by an under-actuated quadrotor UAV equipped with a passive tool in a bilateral teleoperation scheme. To solve the challenging control problem of force regulation in contact interaction while maintaining flight stability and keeping the contact, we use a parallel position/force control method, commensurate to the system dynamics and constraints in which using the compliant structure of the end-effector the rotational degrees of freedom are also utilized to attain a broader range of feasible forces. In a bilateral teleoperation framework, the proposed control method regulates the aerial manipulator position in free flight and the applied force in contact interaction. On the master side, the human operator is provided with force haptic feedback to enhance his/her situational awareness. The validity of the theory and efficacy of the solution are shown by experimental results. This control architecture, integrated with a suitable perception/localization pipeline, could be used to perform outdoor aerial teleoperation tasks in hazardous and/or remote sites of interest.

Energetically Passive Bilateral Teleoperation of a Pneumatic Crawling Robot

2019 ◽  
Author(s):  
Venkat Durbha ◽  
Perry Y. Li
Keyword(s):  
Haptic Feedback ◽  
Reaction Force ◽  
Human Operator ◽  
Haptic Interfaces ◽  
Bilateral Teleoperation ◽  
Physical Effort ◽  
Pneumatic Actuators ◽  
Foot Placement ◽  
Mechanical Tool ◽  
Control Methodology

Abstract This paper presents the control methodology and experimental results for the bilateral haptic tele-operation of a pneumatic actuated crawling robot. The two front legs of a robot are teleoperated via a pair of PHANToM haptic interfaces. The system gives the human operator the impression that he/she is physically moving and positioning the robot legs. As the legs hit the ground, the operator would also feel the reaction force via the haptic feedback provided by the PHANToMs. To reduce the physical effort by the operator, kinematic and power scaling factors are applied. For stable tele-operation, the closed loop system is controlled to behave like a common energetically passive mechanical tool interacting with the human operator (on the PHANToM’s end) and the physical environment (on the Crawler’s end). The control design strategy treats the pneumatic actuators as a two-port nonlinear spring. While the mechanical port of the actuator acts on the mechanical structure of the crawler’s leg, the fluid port of the actuator is controlled to mimic the interaction between the pneumatic spring and the PHANToM, and to achieve co-ordination. The control methodology has been tested experimentally. While performing crawling motion, the RMS error of the robot foot placement error was 7mm, well within the crawler’s foot diameter of 25.4mm.

Switched-Impedance Control of Surgical Robots in Teleoperated Beating-Heart Surgery

2018 ◽  
Vol 03 (03n04) ◽  
pp. 1841003 ◽  
Author(s):  
Lingbo Cheng ◽  
Mahdi Tavakoli
Keyword(s):  
Heart Surgery ◽  
Force Feedback ◽  
Haptic Feedback ◽  
Control Method ◽  
Impedance Control ◽  
Beating Heart ◽  
Human Operator ◽  
Beating Heart Surgery ◽  
Impedance Models ◽  
Fast Motions

A novel switched-impedance control method is proposed and implemented for telerobotic beating-heart surgery. Differing from cardiopulmonary-bypass-based arrested-heart surgery, beating-heart surgery creates challenges for the human operator (surgeon) due to the heart’s fast motions and, in the case of a teleoperated surgical robot, the oscillatory haptic feedback to the operator. This paper designs two switched reference impedance models for the master and slave robots to achieve both motion compensation and nonoscillatory force feedback during slave–heart interaction. By changing the parameters of the impedance models, different performances for both robots are obtained: (a) when the slave robot does not make contact with the beating heart, the slave robot closely follows the motion of the master robot as in a regular teleoperation system, (b) when contact occurs, the slave robot automatically compensates for the fast motions of the beating heart while the human operator perceives the nonoscillatory component of the slave–heart interaction forces, creating the feeling of making contact with an idle heart for the human operator. The proposed method is validated through simulations and experiments.

scholarly journals Improvement of dynamic characteristics of manipulator driven by a gas-liquid phase-change actuator using an antagonistic drive

2018 ◽  
Vol 192 ◽  
pp. 02015
Author(s):  
Tomonori Kato ◽  
Kenya Higashijima ◽  
Yusuke Kuradome ◽  
Kohei Noguchi ◽  
Manabu Ono
Keyword(s):  
Liquid Phase ◽  
Phase Change ◽  
Dynamic Characteristics ◽  
Force Control ◽  
Control Method ◽  
Pneumatic Actuators ◽  
Research Fields ◽  
Large Size ◽  
Heat Of Evaporation ◽  
Soft Actuators

The goal of this research is to improve the dynamic characteristics of a manipulator composed of pneumatic artificial rubber muscles driven by gas-liquid phase change. Pneumatic actuators, such as pneumatic artificial rubber muscle (PARM) or rubber bellows, have been widely used in many industrial and research fields. They have merits of being compact and lightweight. However, the large size of the compressor driving the actuator is a problem. To overcome this, the authors researched soft actuators driven by the gas-liquid phase change (GLPC) of fluorocarbon. Fluorocarbon (C5F11NO) is a substance with a relatively low boiling point (50 °C) and a low heat of evaporation (104.65 kJ/kg). The heat of evaporation of water is 2260 kJ/kg. This paper presents the overview of an actuator driven by GLPC. Then, fabrication of a manipulator using the GLPC driven PARM, and details of experiments conducted to determine manipulator characteristics are given. To improve the dynamic characteristics of the manipulator, a force control method using the antagonistic drive of two PARMs is proposed, and experiments are conducted to validate the effectiveness of the proposed method.

Disturbance Observer Based Closed Loop Force Control for Haptic Feedback

2007 ◽  
Author(s):  
Abhishek Gupta ◽  
Marcia K. O’Malley ◽  
Volkan Patoglu
Keyword(s):  
Force Control ◽  
Disturbance Observer ◽  
Closed Loop ◽  
Force Feedback ◽  
Haptic Feedback ◽  
Open Loop ◽  
Contact Forces ◽  
Force Sensing ◽  
Haptic Interfaces ◽  
Simulation Fidelity

Most commonly used impedance-type haptic interfaces employ open-loop force control under the assumption of pseudostatic interactions. Advanced force control in such interfaces can increase simulation fidelity through improvement of the transparency of the device, and can further improve robustness. However, closed loop force-feedback is limited both due to the bandwidth limitations of force sensing and the associated cost of force sensors required for its implementation. In this paper, we propose the use of a nonlinear disturbance observer for estimation of contact forces during haptic interactions. This approach circumvents the traditional drawbacks of force sensing while exhibiting the advantages of closed-loop force control in haptic devices. The feedback of contact force information further enables implementation of advanced robot force control techniques such as robust hybrid impedance and admittance control. Simulation and experimental results, utilizing a PHANToM Premium 1.0A haptic interface, are presented to demonstrate the efficacy of the proposed approach.

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.

Bilateral teleoperation with continuously variable scaling and PD force control

2020 ◽  
pp. 014233121989592
Author(s):  
Burak Oztoprak ◽  
Eray A. Baran ◽  
Asif Sabanovic
Keyword(s):  
Real Time ◽  
Force Control ◽  
Control Method ◽  
Continuous Functions ◽  
Complete Analysis ◽  
Bilateral Teleoperation ◽  
Bilateral Control ◽  
Time Operation ◽  
Wide Range ◽  
Real Time Operation

This paper investigates the bilateral teleoperation with the possibility of continuously variable scaling during real-time operation. The algorithm proposed for this purpose provides the operator with the ability to change the scaling gains of force and velocity loops during operation. The controllers are derived to enforce exponentially decaying error dynamics on systems which have inner loop disturbance compensation. The proposed architecture assumes the scale factors as continuous functions of time which have continuous derivatives that are also included in the mathematical derivation. Unlike the existing studies, the presented framework allows real-time adaptation of scaling gains, which provides the user with the ability to conduct coarse and fine motion in the same operation. The Lyapunov stability proof of the proposed method is made and the margins of the controller gains are identified for practical operation. Furthermore, the operational accuracy is enhanced by the application of a PD force control loop which is also new for scaled bilateral teleoperation. The realization of PD loop is made using an [Formula: see text]-[Formula: see text]-[Formula: see text] filter to differentiate the force signal. The algorithm is validated on a setup consisted of two single DOF motion control systems. In order to provide a complete analysis, a wide range of experiments are made, velocity and force scales having sinusoidal patterns with different amplitudes and frequencies. Moreover, comparison with a classical bilateral control architecture is made to highlight the flexibility of the proposed control method. The efficacy of the proposed approach is solidified by the successful tracking responses obtained from these experiments.

A Control Method for Robot Fingers with Three-Axis Force Sensor

2014 ◽  
Vol 614 ◽  
pp. 175-178
Author(s):  
Ming Hua Luo ◽  
Chun Wei Pan ◽  
Xiu Wen Yang ◽  
Xin Hua Luo
Keyword(s):  
Control System ◽  
Force Control ◽  
Force Feedback ◽  
Control Method ◽  
Dynamic Balance ◽  
Force Sensor ◽  
Robot Hand ◽  
Closed Loops ◽  
Force Control System ◽  
Grasping Force

This paper proposed a new grasping method for robot fingers with three-axis force sensors. When a robot hand with two fingers is grasping an object, such as an egg, two closed loops with negative feedback in force-control system are start. When grasping force of the two fingers are equal reference force, dynamic balance is reached. Once tiny sliding between egg and finger occurred, force feedback start immediately, dynamic balance is reached again. In this way, our robot hand can firmly grasps eggs, even if vibration added on the robot hand.

Internet-Based Bilateral Teleoperation Based on Wave Variable With Adaptive Predictor and Direct Drift Control

2005 ◽  
Vol 128 (1) ◽  
pp. 86-93 ◽  
Author(s):  
Ho Ching ◽  
Wayne J. Book
Keyword(s):  
Force Feedback ◽  
Transmission Delay ◽  
Recursive Least Squares ◽  
Bilateral Teleoperation ◽  
Practical Applications ◽  
Wave Variable ◽  
Environmental Force ◽  
Rigid Contact ◽  
The Cost ◽  
Drift Control

In a conventional bilateral teleoperation, transmission delay over the Internet can potentially cause instability. A wave variable algorithm guarantees teleoperation stability under varying transmission delay at the cost of poor transient performance. Adding a predictor on the master side can reduce this undesirable side effect, but that would require a slave model. An inaccurate slave model used in the predictor as well as variations in transmission delay, both of which are likely under realistic situations, can result in steady-state errors. A direct drift control algorithm is used to drive this error to zero, regardless of the source of the error. A semi-adaptive predictor that can distinguish between free space and a rigid contact environment is used to provide a more accurate force feedback on the master side. A full adaptive predictor is also used that estimates the environmental force using recursive least squares with a forgetting factor. This research presents the experimental results and evaluations of the previously mentioned wave-variable-based methods under a realistic operation environment using a real master and slave. The algorithm proposed is innovative in that it takes advantage of the strengths of several control methods to build a promising bilateral teleoperation setup that can function under varying transmission delay, modeling error, and changing environment. Success could lead to practical applications in various fields, such as space-based remote control, and telesurgery.

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