Modeling and Impedance Control of a Two-Manipulator System Handling a Flexible Beam

1997 ◽  
Vol 119 (4) ◽  
pp. 736-742 ◽  
Author(s):  
Dong Sun ◽  
Yunhui Liu
Keyword(s):  
Asymptotic Stability ◽  
Force Feedback ◽  
Impedance Control ◽  
Interaction Force ◽  
Flexible Beam ◽  
New Approach ◽  
Vibration Dynamics ◽  
Lasalle Theorem ◽  
Internal Forces ◽  
Proper Response

This paper presents a new approach of transporting a flexible beam handled by two manipulators to a desired position/orientation while suppressing its vibration, and simultaneously controlling the internal forces between the manipulators and the beam to avoid any damage on the system. The algorithm combines impedance control and an I-type force feedback into one scheme by designing a proper response of the interaction force. No information about the vibration is used in the controller. The asymptotic stability is investigated by using LaSalle theorem, based on the vibration dynamics of the beam approximated by m assumed modes (m → ∞ ). Simulations demonstrate the validity of the proposed method.

scholarly journals Sensorless environment stiffness and interaction force estimation for impedance control tuning in robotized interaction tasks

2021 ◽  
Author(s):  
Loris Roveda ◽  
Dario Piga
Keyword(s):  
Impedance Control ◽  
Interaction Force ◽  
Industrial Robots ◽  
Force Estimation ◽  
Interaction Control ◽  
Stiffness Properties ◽  
Implementation Effort ◽  
Coupling Dynamics ◽  
And Control ◽  
Assembly Tasks

AbstractIndustrial robots are increasingly used to perform tasks requiring an interaction with the surrounding environment (e.g., assembly tasks). Such environments are usually (partially) unknown to the robot, requiring the implemented controllers to suitably react to the established interaction. Standard controllers require force/torque measurements to close the loop. However, most of the industrial manipulators do not have embedded force/torque sensor(s) and such integration results in additional costs and implementation effort. To extend the use of compliant controllers to sensorless interaction control, a model-based methodology is presented in this paper. Relying on sensorless Cartesian impedance control, two Extended Kalman Filters (EKF) are proposed: an EKF for interaction force estimation and an EKF for environment stiffness estimation. Exploiting such estimations, a control architecture is proposed to implement a sensorless force loop (exploiting the provided estimated force) with adaptive Cartesian impedance control and coupling dynamics compensation (exploiting the provided estimated environment stiffness). The described approach has been validated in both simulations and experiments. A Franka EMIKA panda robot has been used. A probing task involving different materials (i.e., with different - unknown - stiffness properties) has been considered to show the capabilities of the developed EKFs (able to converge with limited errors) and control tuning (preserving stability). Additionally, a polishing-like task and an assembly task have been implemented to show the achieved performance of the proposed methodology.

scholarly journals Realization of Force Detection and Feedback Control for Slave Manipulator of Master/Slave Surgical Robot

Sensors ◽  
2021 ◽  
Vol 21 (22) ◽  
pp. 7489
Author(s):  
Hu Shi ◽  
Boyang Zhang ◽  
Xuesong Mei ◽  
Qichun Song
Keyword(s):  
Feedback Control ◽  
Force Feedback ◽  
Impedance Control ◽  
Three Dimensional ◽  
Surgical Instruments ◽  
Force Output ◽  
Software Environment ◽  
Force Detection ◽  
Academic Field ◽  
Learning Machine

Robot-assisted minimally invasive surgery (MIS) has received increasing attention, both in the academic field and clinical operation. Master/slave control is the most widely adopted manipulation mode for surgical robots. Thus, sensing the force of the surgical instruments located at the end of the slave manipulator through the main manipulator is critical to the operation. This study mainly addressed the force detection of the surgical instrument and force feedback control of the serial surgical robotic arm. A measurement device was developed to record the tool end force from the slave manipulator. An elastic element with an orthogonal beam structure was designed to sense the strain induced by force interactions. The relationship between the acting force and the output voltage was obtained through experiment, and the three-dimensional force output was decomposed using an extreme learning machine algorithm while considering the nonlinearity. The control of the force from the slave manipulator end was achieved. An impedance control strategy was adopted to restrict the force interaction amplitude. Modeling, simulation, and experimental verification were completed on the serial robotic manipulator platform along with virtual control in the MATLAB/Simulink software environment. The experimental results show that the measured force from the slave manipulator can provide feedback for impedance control with a delay of 0.15 s.

Vibration Reduction of Flexible Structures Using Extended Input Shaper and Smart Materials

2001 ◽  
Author(s):  
G. Song ◽  
B. Kotejoshyer ◽  
J. Fei
Keyword(s):  
Smart Materials ◽  
Vibration Suppression ◽  
Flexible Structures ◽  
Flexible Beam ◽  
Smart Sensor ◽  
New Approach ◽  
Active Vibration Suppression ◽  
Command Input ◽  
Active Vibration ◽  
Smart Actuator

Abstract This paper presents a new approach of integrating the method of command input shaping and the technique of active vibration suppression for vibration reduction of flexible structures during slew operations. The control object is a flexible composite beam driven by a high torque DC motor with the presence of nonlinearities such as backlash and stick-slip type of friction. Two piezoelectric patches are bonded on the surface of the flexible beam near its cantilevered end and are used as the smart actuator and the smart sensor respectively. In this new approach, the method of command input shaping is used to modify the existing command so that less vibration will be caused by the command itself. To overcome the nonlinearities associated with the DC motor, an extended shaper is designed. The technique of active vibration suppression using smart materials is used to actively control the vibration during and after the slew. With this pair of smart actuator and smart sensor, a strain rate feedback (SRF) controller is designed for active vibration suppression. With the extended Zero Vibration Derivative (ZVD) shaper and the SRF controller, the proposed new approach can effectively reduce the vibration of the flexible beam during slew operations.

Learning peg-in-hole assembly using Cartesian DMPs with feedback mechanism

2020 ◽  
Vol 40 (6) ◽  
pp. 895-904
Author(s):  
Nailong Liu ◽  
Xiaodong Zhou ◽  
Zhaoming Liu ◽  
Hongwei Wang ◽  
Long Cui
Keyword(s):  
Force Feedback ◽  
Impedance Control ◽  
Dynamic Performance ◽  
Feedback Mechanism ◽  
Learning From Demonstration ◽  
Content Type ◽  
Control Approach ◽  
Cartesian Space ◽  
Compliant Behavior ◽  
Dynamic Movement Primitives

Purpose This paper aims to enable the robot to obtain human-like compliant manipulation skills for the peg-in-hole (PiH) assembly task by learning from demonstration. Design/methodology/approach A modified dynamic movement primitives (DMPs) model with a novel hybrid force/position feedback in Cartesian space for the robotic PiH problem is proposed by learning from demonstration. To ensure a compliant interaction during the PiH insertion process, a Cartesian impedance control approach is used to track the trajectory generated by the modified DMPs. Findings The modified DMPs allow the robot to imitate the trajectory of demonstration efficiently and to generate a smoother trajectory. By taking advantage of force feedback, the robot shows compliant behavior and could adjust its pose actively to avoid a jam. This feedback mechanism significantly improves the dynamic performance of the interactive process. Both the simulation and the PiH experimental results show the feasibility and effectiveness of the proposed model. Originality/value The trajectory and the compliant manipulation skill of the human operator can be learned simultaneously by the new model. This method adopted a modified DMPs model in Cartesian space to generate a trajectory with a lower speed at the beginning of the motion, which can reduce the magnitude of the contact force.

Bilateral teleoperation of mobile robots

Robotica ◽  
2002 ◽  
Vol 20 (2) ◽  
pp. 213-221 ◽  
Author(s):  
Vicente Mut ◽  
José Postigo ◽  
Emanuel Slawiñski ◽  
Benjamin Kuchen
Keyword(s):  
Mobile Robot ◽  
Mobile Robots ◽  
Visual Information ◽  
Force Feedback ◽  
Control Structure ◽  
Interaction Force ◽  
Tactile Feedback ◽  
Linear Velocity ◽  
Bilateral Teleoperation

A control structure for the bilateral teleoperation of mobile robots, with tactile feedback and visual information of the interaction force is proposed in this paper. Also an impedance controller is implemented in the mobile robot structure that guarantees the linear velocity be within a desired fixed range without saturation in the actuators. To illustrate the performance of the proposed control structure, experiments on a Pioneer 2 mobile robot teleoperated with a commercial joystick with force feedback are shown.

Impedance Control of Cable-Driven Mechanisms

2008 ◽  
Author(s):  
Siavash Rezazadeh ◽  
Saeed Behzadipour
Keyword(s):  
Force Feedback ◽  
Control Method ◽  
Impedance Control ◽  
Tensile Force ◽  
Classical Problem ◽  
The Body ◽  
Control Input ◽  
Body Parts ◽  
Lagrange’S Equation ◽  
Cable Forces

In this work, an impedance control method is developed and applied to two cable-driven mechanisms. The first one is a classical problem of driving a rigid body in 3-D space by seven cables. Our approach is based on the impedance control of rigid link manipulators which is then extended to include the specific considerations of the cable-driven mechanisms such as maintaining the tensile force in the cables. The method is then extended to the serial multibody cable-driven mechanisms. The motivation for this problem is the possible application of cable-driven systems in the rehabilitative exercises such as physical and/or occupational therapies. In this case, the human body acts as a multibody system which is driven by cables attached. The impedance control in such application facilitates the comfort of the patient by providing the necessary compliance while moving the body parts. The formulation of the problem is developed using Lagrange’s equation and the control input (which is the cable forces) is calculated based on the position and/or force feedback from the multibody. Simulation results demonstrate the effectiveness of the presented method.

The Problem of Consideration Torsion Emergence in Beams

2018 ◽  
Vol 7 (3.2) ◽  
pp. 141 ◽  
Author(s):  
Sergiy Hudz ◽  
Grygorii Gasii ◽  
Volodymyr Pents
Keyword(s):  
Theoretical Model ◽  
Bearing Capacity ◽  
Work Conditions ◽  
Steel Beams ◽  
New Approach ◽  
Initial Imperfections ◽  
Advantages And Disadvantages ◽  
Internal Forces ◽  
Partially Restrained ◽  
Material Saving

The calculation of the steel unrestrained and partially restrained roof beams with initial imperfections main stages is discussed. Restraining can be done by structures attached to the steel beams, namely, profiled flooring and discrete joints. On the basis of the new approach to the internal forces analysis and the geometric properties specification, the purpose was to find and describe the differences in the beam work as the part of roofing, which distinguishes it from the work conditions of the free supported beam. The features of the beam operation with the joint flexural and torsion are singled out. The need to improve the existing theoretical model for present deficiencies elimination is indicated. The bearing capacity determining methods for the flexible elements stability exposed to bending and bending with torsion are compared. Their advantages and disadvantages are revealed. It is proposed to increase the material saving by applying calculations. At the end of the article, conclusions regarding the consideration of investigated factors are given.  

Interaction Control for Rehabilitation Robotics via a Low-Cost Force Sensing Handle

2013 ◽  
Author(s):  
Andrew Erwin ◽  
Fabrizio Sergi ◽  
Vinay Chawda ◽  
Marcia K. O’Malley
Keyword(s):  
Grip Force ◽  
Force Feedback ◽  
Low Cost ◽  
Interaction Force ◽  
Rehabilitation Robotics ◽  
Haptic Interface ◽  
Force Sensing ◽  
Improve Performance ◽  
Feedback Controllers ◽  
Interaction Control

This paper investigates the possibility of implementing force-feedback controllers using measurement of interaction force obtained through force-sensing resistors (FSRs), to improve performance of human interacting robots. A custom sensorized handle was developed, with the capability of simultaneously measuring grip force and interaction force during robot-aided rehabilitation therapy. Experiments are performed in order to assess the suitability of FSRs to implement force-feedback interaction controllers. In the force-feedback control condition, the applied force for constant speed motion of a linear 1DOF haptic interface is reduced 6.1 times compared to the uncontrolled condition, thus demonstrating the possibility of improving transparency through force-feedback via FSRs.

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