scholarly journals Position Control via Force Feedback in the Port-Hamiltonian Framework

2016 ◽  
pp. 181-207 ◽  
Author(s):  
Mauricio Muñoz-Arias ◽  
Jacquelien M. A. Scherpen ◽  
Daniel A. Dirksz
Keyword(s):  
Force Feedback ◽  
Position Control

The Development of an Experimental Force Feedback Dynamometer to Investigate the Real Time Control of an Oscillating Wave Surge Converter

2013 ◽  
Author(s):  
Daniel Banks ◽  
Jos van ’t Hoff ◽  
Kenneth Doherty
Keyword(s):  
Force Feedback ◽  
Position Control ◽  
Experimental Testing ◽  
Control Strategies ◽  
Small Scale ◽  
Real Time Control ◽  
Time Control ◽  
Scale Models ◽  
Damping Torque ◽  
And Control

An Oscillating Wave Surge Converter (OWSC) is a Wave Energy Converter (WEC) that consists of a bottom-hinged flap which oscillates due to wave action. Extensive research has been performed on this type of WEC through small scale experimental wave tank tests. One of the key challenges of experimental testing is replicating the characteristics of the Power Take-Off (PTO) system of the equivalent full scale WEC. Many scale models rely on simplified mechanical designs to simulate a PTO system. This can often restrict the experimental research into the influence of PTO design and control strategies of WECs. In order to model PTO systems and control strategies more accurately other tools are needed. This paper describes the design and build of a PLC controlled Force Feedback Dynamometer (FFD) system that enables the testing of more sophisticated control strategies applicable to an OWSC through fast application of a variable PTO damping torque. A PLC system is shown to be a viable control for PTO strategy investigations through velocity triggered damping levels. Examples of both PTO and position control strategies are presented.

scholarly journals Force feedback-based quality monitoring of the friction stir welding process utilizing an analytic algorithm

2020 ◽  
Author(s):  
P. Rabe ◽  
A. Schiebahn ◽  
U. Reisgen
Keyword(s):  
Friction Stir Welding ◽  
Monitoring System ◽  
Force Feedback ◽  
Weld Seam ◽  
Position Control ◽  
Welding Process ◽  
Quality Monitoring ◽  
Welding Parameters ◽  
Process Data ◽  
Friction Stir

AbstractThe friction stir welding (FSW) process is known as a solid-state welding process, comparatively stable against external influences. Therefore, the process is commonly used with fixed welding parameters, utilizing axial force control or position control strategies. External and internal process disturbances introduced by workpiece, gap tolerance, tool wear, or machine/tool inadequacies are rarely monitored, and conclusions about the weld seam quality, based on the recorded process data, are not drawn. This paper describes an advancement, improving on research into the correlation of process force feedback events or gradual force changes and the resulting weld seam characteristics. Analyzing the correlation between examined weld sections and high-resolution rate force data, a quality monitoring system based on an analytic algorithm is described. The monitoring system is able to accurately distinguish sound welds from such with internal (void) and external (flash) defects.

Position control of robot manipulators with elastic joints using force feedback

1990 ◽  
Vol 7 (4) ◽  
pp. 535-554 ◽  
Author(s):  
Nenad Kircanski ◽  
Aleksandar Timcenko ◽  
Miomir Vukobratovic
Keyword(s):  
Force Feedback ◽  
Position Control ◽  
Robot Manipulators ◽  
Elastic Joints

scholarly journals Dynamic External Force Feedback Loop Control of a Robot Manipulator Using a Neural Compensator—Application to the Trajectory Following in an Unknown Environment

2009 ◽  
Vol 19 (1) ◽  
pp. 113-126 ◽  
Author(s):  
Farid Ferguene ◽  
Redouane Toumi
Keyword(s):  
External Force ◽  
Control Strategy ◽  
Feedback Loop ◽  
Force Feedback ◽  
Position Control ◽  
Robot Manipulator ◽  
Suggested Approach ◽  
Loop Control ◽  
Unknown Environment ◽  
Trajectory Following

Dynamic External Force Feedback Loop Control of a Robot Manipulator Using a Neural Compensator—Application to the Trajectory Following in an Unknown EnvironmentForce/position control strategies provide an effective framework to deal with tasks involving interaction with the environment. One of these strategies proposed in the literature is external force feedback loop control. It fully employs the available sensor measurements by operating the control action in a full dimensional space without using selection matrices. The performance of this control strategy is affected by uncertainties in both the robot dynamic model and environment stiffness. The purpose of this paper is to improve controller robustness by applying a neural network technique in order to compensate the effect of uncertainties in the robot model. We show that this control strategy is robust with respect to payload uncertainties, position and environment stiffness, and dry and viscous friction. Simulation results for a three degrees-of-freedom manipulator and various types of environments and trajectories show the effectiveness of the suggested approach compared with classical external force feedback loop structures.

scholarly journals Design and development of a Stewart platform assisted and navigated transsphenoidal surgery

2019 ◽  
pp. 961-972 ◽  
Author(s):  
SELÇUK KİZİR ◽  
ZAFER BİNGÜL
Keyword(s):  
Trajectory Tracking ◽  
Transsphenoidal Surgery ◽  
Force Feedback ◽  
Position Control ◽  
Stewart Platform ◽  
Robotic System ◽  
Haptic Device ◽  
Head Model ◽  
Endoscopic Transsphenoidal Surgery ◽  
Model Free

In this study, technical details of a Stewart platform (SP) based robotic system as an endoscope positioner and holder for endoscopic transsphenoidal surgery are presented. Inverse and forward kinematics, full dynamics, and the Jacobian matrix of the robotic system are derived and simulated in MATLAB/Simulink. The required control structure for the trajectory and position control of the SP is developed and verified by several experiments. The robotic system can be navigated using a six degrees of freedom (DOF) joystick and a haptic device with force feedback. Position and trajectory control of the SP in the joint space is achieved using a new model-free intelligent PI (iPI) controller and it is compared with the classical PID (proportional-integral-derivative) controller. Trajectory tracking experimental results showed that the tracking performance of iPI is better than that of PID and the total RMSE of the trajectory tracking is decreased by 17.64% using the iPI controller. The validity of the robotic system is proven in the endoscopic transsphenoidal surgery performed on a realistic head model in the laboratory and on a cadaver in the Institute of Forensic Medicine. The key feature of the system developed here is to operate the endoscope via the joystick or haptic device with force feedback under iPI control. Usage of this system helps surgeons in long, fatiguing, and complex operations. This system can generate new possibilities for transsphenoidal surgery such as fully automated robotic surgery systems.

scholarly journals Interacting With Grasped Objects in Expanded Haptic Workspaces Using the Bubble Technique

2015 ◽  
Vol 15 (4) ◽  
Author(s):  
Ryan A. Pavlik ◽  
Judy M. Vance
Keyword(s):  
Virtual Environments ◽  
Collision Detection ◽  
Rate Control ◽  
Force Feedback ◽  
Position Control ◽  
Restoring Force ◽  
End Effector ◽  
Base Position ◽  
Bubble Interaction ◽  
Control Devices

Haptic force-feedback can provide useful cues to users of virtual environments. Body-based haptic devices are portable but the more commonly used ground-based devices have workspaces that are limited by their physical grounding to a single base position and their operation as purely position-control devices. The “bubble technique” has recently been presented as one method of expanding a user's haptic workspace. The bubble technique is a hybrid position-rate control system in which a volume, or “bubble,” is defined entirely within the physical workspace of the haptic device. When the device's end effector is within this bubble, interaction is through position control. When the end effector moves outside this volume, an elastic restoring force is rendered, and a rate is applied that moves the virtual accessible workspace. Publications have described the use of the bubble technique for point-based touching tasks. However, when this technique is applied to simulations where the user is grasping virtual objects with part-to-part collision detection, unforeseen interaction problems surface. Methods of addressing these challenges are introduced, along with discussion of their implementation and an informal investigation.

Inertial-Force Feedback for the Treadport Locomotion Interface

2000 ◽  
Vol 9 (1) ◽  
pp. 1-14 ◽  
Author(s):  
Robert R. Christensen ◽  
John M. Hollerbach ◽  
Yangming Xu ◽  
Sanford G. Meek
Keyword(s):  
Real World ◽  
Force Feedback ◽  
Position Control ◽  
Inertial Force ◽  
The Subject ◽  
Locomotion Interface

The inertial force due to the acceleration of a locomotion interface is identified as a difference between virtual and real-world locomotion. To counter the inertial force, inertial-force feedback was implemented for the Treadport, a locomotion interface. A force controller was designed for a mechanical tether to apply the feedback force to the user. For the case of the user accelerating forward from rest, psychophysical ex periments showed that subjects preferred inertial-force feedback to a spring-feedback force proportional to position or to position control, where the force feedback maintained a force of zero on the subject.

Hybrid Target Tracking Manipulation Theories for Combined Force and Position Control in Open and Closed Loop Manipulators

2005 ◽  
Author(s):  
David J. Giblin ◽  
Zongliang Mu ◽  
ZhongXue Gan ◽  
Kazem Kazerounian
Keyword(s):  
Inverse Kinematics ◽  
Closed Loop ◽  
Force Feedback ◽  
Position Control ◽  
Parallel Manipulators ◽  
Joint Space ◽  
Loop Control ◽  
Joint Torques ◽  
Position Data ◽  
Direct Kinematics

This paper presents a new manipulation theory for controlling compliant motions of a robotic manipulator. In previous closed loop control methods, both direct kinematics and inverse kinematics of a manipulator must be resolved to convert feedback force and position data from Cartesian space to joint space. However, in many cases, the solution of direct kinematics in a parallel manipulator or the solution of inverse kinematics in a serial manipulator is not easily available. In this study, the force and position data are packed into one set of “motion feedback,” by replacing the force errors with virtual motion quantities, or one set of “force feedback,” by replacing motion errors with virtual force quantities. The joint torques are adjusted based on this combined feed back package. Since only Jacobian of direct kinematics or Jacobian of inverse kinematics is used in the control scheme, the computational complexity is reduced significantly. The applications of this theory are demonstrated in simulation experiments with both serial and parallel manipulators.

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