A hybrid impedance control scheme for underwater welding robots with a passive foundation in the controller domain

SIMULATION ◽  
2017 ◽  
Vol 93 (7) ◽  
pp. 619-630 ◽  
Author(s):  
Sunil Kumar ◽  
Vikas Rastogi ◽  
Pardeep Gupta
Keyword(s):  
Minimum Distance ◽  
Position Control ◽  
Robot Manipulator ◽  
Impedance Control ◽  
Graph Model ◽  
Proportional Integral Derivative ◽  
End Effector ◽  
Flexible Arm ◽  
Control Scheme ◽  
Effective Stability

A hybrid impedance control scheme for the force and position control of an end-effector is presented in this paper. The interaction of the end-effector is controlled using a passive foundation with compensation gain. For obtaining the steady state, a proportional–integral–derivative controller is tuned with an impedance controller. The hybrid impedance controller is implemented on a terrestrial (ground) single-arm robot manipulator. The modeling is done by creating a bond graph model and efficacy is substantiated through simulation results. Further, the hybrid impedance control scheme is applied on a two-link flexible arm underwater robot manipulator for welding applications. Underwater conditions, such as hydrodynamic forces, buoyancy forces, and other disturbances, are considered in the modeling. During interaction, the minimum distance from the virtual wall is maintained. A simulation study is carried out, which reveals some effective stability of the system.

Position-Based Fractional-Order Impedance Control of a 2 DOF Serial Manipulator

Robotica ◽  
2021 ◽  
pp. 1-15
Author(s):  
Selçuk Kizir ◽  
Ali Elşavi
Keyword(s):  
Fractional Order ◽  
Position Control ◽  
Robot Manipulator ◽  
Impedance Control ◽  
Torque Control ◽  
Control Scheme ◽  
Absorption Performance ◽  
And Performance ◽  
Comparison Of The Results ◽  
Robotic Tasks

SUMMARY Impedance control is one of the interaction and force control methods that has been widely applied in the research of robotics. In this paper, a new position-based fractional-order impedance control scheme is proposed and applied to a 2 DOF serial manipulator. An RR robot manipulator with full arm dynamics and its environment were designed using Matlab/Simulink. The position control of the manipulator was utilized based on computed torque control to cancel out the nonlinearities existing on the dynamic model of the robot. Parameters of classical impedance controller (CIC) and proposed fractional-order impedance controller (FOIC) were optimized in order to minimize impact forces for comparison of the results in three conditions. In CIC condition: three constant parameters of the impedance controller were optimized: in Frac_λμ condition: Only non-integer parameters of the FOIC were re-optimized after the parameters in CIC had been accepted, and in Frac_all condition: all parameters of the FOIC were re-optimized. In order to show the effectiveness of the proposed method, simulations were conducted for all cases and performance indices were computed for the interaction forces. Results showed that impacts were reduced with an improvement of 26.12% from CIC to Frac_ λμ and an improvement of 47.21% from CIC to Frac_all. The proposed scheme improves the impedance behavior and robustness showing better impact absorption performance, which is needed in many challenging robotic tasks and intelligent mechatronic devices.

Impedance Control of Dual-Arm Systems Based on the Object with Senseless Force

2013 ◽  
Vol 765-767 ◽  
pp. 1920-1923
Author(s):  
Li Jiang ◽  
Yang Zhou ◽  
Bin Wang ◽  
Chao Yu
Keyword(s):  
Numerical Simulations ◽  
Relative Position ◽  
Position Control ◽  
Impedance Control ◽  
Force Sensors ◽  
Operational Space ◽  
Novel Approach ◽  
Control Scheme ◽  
Statics And Dynamics ◽  
Dual Arm

A novel approach to impedance control based on the object is proposed to control dual-arm systems with senseless force. Considering the motion of the object, the statics and dynamics of the dual-arm systems are modeled. Extending the dynamics of dual-arm system and the impedance of object to the operational space, impedance control with senseless force is presented. Simulations on a dual-arm system are carried out to demonstrate the performance of the proposed control scheme. Comparing with position control, results of numerical simulations show that the proposed scheme realizes suitable compliant behaviors in terms of the object, and minimizes the error of the relative position between the manipulators even without force sensors.

Adaptive Sliding Mode Impedance Control of Single-Link Flexible Manipulators interacting with the Environment at an Unknown Intermediate Point

Robotica ◽  
2019 ◽  
Vol 38 (9) ◽  
pp. 1642-1664 ◽  
Author(s):  
Ali Fayazi ◽  
Naser Pariz ◽  
Ali Karimpour ◽  
V. Feliu-Batlle ◽  
S. Hassan HosseinNia
Keyword(s):  
Position Control ◽  
Sliding Mode ◽  
Impedance Control ◽  
Detection Algorithm ◽  
Reference Trajectory ◽  
Constrained Motion ◽  
Intermediate Point ◽  
Control Scheme ◽  
Single Link ◽  
Motion Mode

SUMMARYThis paper proposes an adaptive robust impedance control for a single-link flexible arm when it encounters an environment at an unknown intermediate point. First, the intermediate collision point is estimated using a collision detection algorithm. The controller, then, switches from free to constrained motion mode. In the unconstrained motion mode, the exerted force to environment is nearly zero. Thus, the reference trajectory is a prescribed desired trajectory in position control. In the constrained motion mode, the reference trajectory is determined by the desired target dynamic impedance. The simulation results demonstrate the efficiency of proposed control scheme.

A Modular 2-DOF Serial Robot Manipulator for Education in Robot Control

2016 ◽  
Author(s):  
Stephen Mascaro
Keyword(s):  
Robot Control ◽  
Inverse Dynamics ◽  
Position Control ◽  
Sliding Mode ◽  
Feedforward Control ◽  
Robot Manipulator ◽  
Impedance Control ◽  
Force Sensor ◽  
Control Techniques ◽  
Serial Robot

This paper describes a modular 2-DOF serial robot manipulator and accompanying experiments that have been developed to introduce students to the fundamentals of robot control. The robot is designed to be safe and simple to use, and to have just enough complexity (in terms of nonlinear dynamics) that it can be used to showcase and compare the performance of a variety of textbook robot control techniques including computed torque feedforward control, inverse dynamics control, robust sliding-mode control, and adaptive control. These various motion control schemes can be easily implemented in joint space or operational space using a MATLAB/Simulink real-time interface. By adding a simple 2-DOF force sensor to the end-effector, the robot can also be used to showcase a variety of force control techniques including impedance control, admittance control, and hybrid force/position control. The 2-DOF robots can also be used in pairs to demonstrate control architectures for multi-arm coordination and master/slave teleoperation. This paper will describe the 2-DOF robot and control hardware/software, illustrate the spectrum of robot control methods that can be implemented, and show sample results from these experiments.

scholarly journals Robust position-based impedance control of lightweight single-link flexible robots interacting with the unknown environment via a fractional-order sliding mode controller

Robotica ◽  
2018 ◽  
Vol 36 (12) ◽  
pp. 1920-1942 ◽  
Author(s):  
Ali Fayazi ◽  
Naser Pariz ◽  
Ali Karimpour ◽  
Seyed Hassan Hosseinnia
Keyword(s):  
Fractional Order ◽  
Position Control ◽  
Sliding Mode ◽  
Impedance Control ◽  
Lyapunov Theory ◽  
Reference Trajectory ◽  
Constrained Motion ◽  
Unknown Environment ◽  
Control Scheme ◽  
Single Link

SUMMARYThis paper presents a fractional-order sliding mode control scheme equipped with a disturbance observer for robust impedance control of a single-link flexible robot arm when it comes into contact with an unknown environment. In this research, the impedance control problem is studied for both unconstrained and constrained maneuvers. The proposed control strategy is robust with respect to the changes of the environment parameters (such as stiffness and damping coefficient), the unknown Coulomb friction disturbances, payload, and viscous friction variations. The proposed control scheme is also valid for both unconstrained and constrained motions. Our novel approach automatically switches from the free to the constrained motion mode using a simple algorithm of contact detection. In this regard, an impedance control scheme is proposed with the inner loop position control. This means that in the free motion, the applied force to the environment is zero and the reference trajectory for the inner loop position control is the desired trajectory. However, in the constrained motion the reference trajectory for the inner loop is determined by the desired impedance dynamics. Stability of the closed loop control system is proved by Lyapunov theory. Several numerical simulations are carried out to indicate the capability and the effectiveness of the proposed control scheme.

scholarly journals Position control for haptic device based on discrete-time proportional integral derivative controller

2022 ◽  
Vol 12 (1) ◽  
pp. 269
Author(s):  
Nguyen Van Tan ◽  
Khoa Nguyen Dang ◽  
Pham Duc Dai ◽  
Long Vu Van
Keyword(s):  
Discrete Time ◽  
Pid Controller ◽  
Position Control ◽  
Haptic Device ◽  
Advanced Technology ◽  
Proportional Integral Derivative ◽  
Force Output ◽  
Kinematic Equation ◽  
End Effector ◽  
Proportional Integral

Haptic devices had known as advanced technology with the goal is creating the experiences of touch by applying forces and motions to the operator based on force feedback. Especially in unmanned aerial vehicle (UAV) applications, the position of the end-effector Falcon haptic sets the velocity command for the UAV. And the operator can feel the experience vibration of the vehicle as to the acceleration or collision with other objects through a forces feedback to the haptic device. In some emergency cases, the haptic can report to the user the dangerous situation of the UAV by changing the position of the end-effector which is be obtained by changing the angle of the motor using the inverse kinematic equation. But this solution may not accurate due to the disturbance of the system. Therefore, we proposed a position controller for the haptic based on a discrete-time proportional integral derivative (PID) controller. A Novint Falcon haptic is used to demonstrate our proposal. From hardware parameters, a Jacobian matrix is calculated, which combines with the force output from the PID controller to make the torque for the motors of the haptic. The experiment was shown that the PID has high accuracy and a small error position.

Robot Manipulation Using Virtual Compliance Control

2000 ◽  
Vol 12 (5) ◽  
pp. 567-576 ◽  
Author(s):  
Hisaaki Hirabayashi ◽  
◽  
Koichi Sugimoto ◽  
Atsuko Enomoto ◽  
Ichirou Ishimaru ◽  
...  
Keyword(s):  
Real Time ◽  
Position Control ◽  
Control Method ◽  
Robot Manipulator ◽  
Impedance Control ◽  
Experimental Results ◽  
Velocity Control ◽  
Compliance Control ◽  
Robot Hands ◽  
Control Response

Experimental results proved that a unified method of impedance control, already presented as virtual compliance control, can make a robot manipulator without any special mechanism perform various patterns of motion, corresponding to the specified software parameters of the control method. Outcomes demonstrated are as follows. (1) The proposed control method can change the characteristics of spring constant and dashpot constant, that is impedance, of 6 degree of freedom (translational: 3 , rotational: 3) of the robot hand. (2) The change of characteristics mentioned above in (1) can be treated equivalently in both translational and rotational. (3) The change of characteristics mentioned above in (1) and (2) can be implemented in real time. (4) The proposed control method can change the characteristics of transient response in velocity control of 6-d.o.f. of the robot hands. (5) The change of characteristics mentioned above in (4) can be treated equivalently both translationally and rotationally. (6) The change of characteristics mentioned above in (4) and (5) can be implemented in real time. (7) The proposed control method can make impedance control applied to one axis, and position control applied to other axis simultaneously, as to 6-d.o.f. of the robot hands. (8) Experimental results mentioned above in (1) - (7) imply the following advantage and disadvantage; advantage: a unified control method that can perform various patterns of motion by specifying software parameters, disadvantage: control response is not necessarily precise that is because proposed control method is base on not dynamics but kinematics.

scholarly journals Aerial Physical Interaction in Grabbing Conditions with Lightweight and Compliant Dual Arms

2020 ◽  
Vol 10 (24) ◽  
pp. 8927
Author(s):  
Alejandro Suarez ◽  
Pedro J. Sanchez-Cuevas ◽  
Guillermo Heredia ◽  
Anibal Ollero
Keyword(s):  
Impedance Control ◽  
Physical Interaction ◽  
Position Sensor ◽  
Aerial Manipulation ◽  
End Effector ◽  
Control Scheme ◽  
External Forces ◽  
Dual Arm ◽  
Manipulation Robot ◽  
Aerial Platform

This paper considers the problem of performing bimanual aerial manipulation tasks in grabbing conditions, with one of the arms grabbed to a fixed point (grabbing arm) while the other conducts the task (operation arm). The goal was to evaluate the positioning accuracy of the aerial platform and the end effector when the grabbing arm is used as position sensor, as well as to analyze the behavior of the robot during the aerial physical interaction on flight. The paper proposed a control scheme that exploits the information provided by the joint sensors of the grabbing arm for estimating the relative position of the aerial platform w.r.t. (with respect to) the grabbing point. A deflection-based Cartesian impedance control was designed for the compliant arm, allowing the generation of forces that help the aerial platform to maintain the reference position when it is disturbed due to external forces. The proposed methods were validated in an indoor testbed with a lightweight and compliant dual arm aerial manipulation robot.

Adaptive Impedance Control of Robot Manipulators based on Function Approximation Technique

Robotica ◽  
2004 ◽  
Vol 22 (4) ◽  
pp. 395-403 ◽  
Author(s):  
Ming-Chih Chien ◽  
An-Chyau Huang
Keyword(s):  
Function Approximation ◽  
Robot Manipulator ◽  
Impedance Control ◽  
Lyapunov Stability Theory ◽  
Approximation Technique ◽  
Control Scheme ◽  
Approximation Errors ◽  
Adaptive Impedance Control ◽  
Function Approximation Technique ◽  
Finite Linear

This paper presents an adaptive impedance control scheme for an $n$-link constrained rigid robot manipulator without using the regressor. In addition, inversion of the estimated inertia matrix is also avoided and the new design is free from end-point acceleration measurements. The dynamics of the robot manipulator is assumed that all of the matrices in robot model are unavailable. Since these matrices are time-varying and their variation bounds are not given, traditional adaptive or robust designs do not apply. The function approximation technique is used here to represent uncertainties in some finite linear combinations of the orthogonal basis. The dynamics of the output tracking can thus be proved to be a stable first order filter driven by function approximation errors. Using the Lyapunov stability theory, a set of update laws is derived to give closed loop stability with proper tracking performance. A 2 DOF planar robot with environment constraint is used in the computer simulations to test the efficacy of the proposed scheme.

scholarly journals Simulation and experimental study on PID control of a quadrotor MAV with perturbation

2020 ◽  
Vol 9 (5) ◽  
pp. 1811-1818
Author(s):  
A. Noordin ◽  
M. A. M. Basri ◽  
Z. Mohamed
Keyword(s):  
Pid Control ◽  
Gaussian Noise ◽  
Position Control ◽  
Area Network ◽  
Proportional Integral Derivative ◽  
External Disturbances ◽  
Control Scheme ◽  
Air Vehicle ◽  
Simulation Parameter ◽  
Personal Area Network

This paper presents a proportional-integral-derivative (PID) flight controller for a quadrotor micro air vehicle (MAV). The MAV (Parrot Mambo minidrones) is small, therefore, a slight perturbation will affect its performance. Hence, for the actuated dynamics, roll (ϕ), pitch (θ), yaw (ψ), and z stabilization, a PID control scheme is proposed. Furthermore, the same controller technique is also applied for under-actuated dynamics x and y position control. The newtonian model is simulated using simulink with a normal Gaussian noise of force as external disturbances. using simulink support package for Parrot Minidrones by MATLAB and based on the simulation parameter, the algorithm is deployed using Bluetooth® Low energy connection via personal area network (PAN). A slight force by hand is applied as perturbation during hovering to investigation system performances. Finally, the simulation and experimental on this commercial MAV, Parrot Mambo minidrones shows good performance of the flight controller scheme in the presence of external disturbances.

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