Force Control

During laparoscopic surgeries, primary surgical tool insertion is the demanding and strenuous task. As the surgeon is unaware of the type of the tissue and associated parameters to conduct the insertion, therefore, to ease the procedure, the movement of the surgical tool needs to be controlled. It's the operational capabilities that are to be manipulated to perform a smooth surgery even from a distant location. In this study, a robot system is being introduced for laparoscopic primary surgical tool insertion. It will incorporate a novel observer based dynamic control along with robot assisted bilateral control. Moreover, a virtual spring damper force lock system is introduced through which the slave system will notify the master regarding the target achieved and excessive force. The validation of the proposed control system is experimented with bilaterally controlled MU-LapaRobot. The experiment is comprising 3 cases of bilateral control criteria which are non-contact motion, contact motion, and limit force locking. The results defined the same value for contact and non-contact motion by 0.3N. The results depicted a force error of 3.6% and a position error of 5.8% which validated the proposed algorithm.

Abstract—The converter topology with a minimum number of power devices and control implementations to facilitate the pulsa-tion-free force control of the linear switched reluctance machines are investigated for the first time in this paper. The minimization of the devices offers cost reduction, ...

AMADEUS is a dexterous subsea robot hand incorporating force and slip contact sensing, using fluid filled tentacles for fingers. Hydraulic pres-sure variations in each of three flexible tubes (bellows) in each finger create a bending moment, and consequent motion or increase in ...

Özetçe Bu çalışmada 6 serbestlik dereceli insansı robot kolu konum ve kuvvet kontrolüne yer verilmiştir. Robotik alanında kullanılan kontrol yöntemleri incelenmiş, insansı robot kolu için yapılması istenebilecek görevler göz önünde bulundurularak en uygun görülen Empedans Kontrol yöntemi seçilmiştir. Bu yöntem, belirlenen senaryo ile benzetim çalışmaları üzerinde analiz edilmiştir. Robot kol modeli Solidworks programında yapılan çizimi, SimMechanics araç çubuğu ile Matlab Simulink ortamına aktarılmış, benzetim çalışmaları bu arayüzden yürütülmüştür. Görev olarak çember çizimi tanımlanmış ve robot kolunun hareketli bir levha üzerine çizim yapması istenmiştir. Gerçekleştirilme açısından değerlendirilip, konum ve kuvvet kontrolü için en uygun görülen Temel Empedans Kontrol Yöntemi seçilmiştir. Bu yöntemde hassas olarak belirlenmesi gereken katılık, sönüm, konum ve hız modifikasyon matrisleri bulunmaktadir. Bunlar kontrolcü katsayılardır. Katsayıların belirlenmesinde öncelikle deneme-yanılma yöntemi kullanılmış ve kabul edilebilir konum hatalarıyla uç eyleyici konum-kuvvet kontrolü gerçekleştirilmiştir. Abstract One of the most important parameters is that the robot can be controlled to perform a desired task. It is essential that position or force control or both should be provided. In this study, the position and force control of a robot arm with 6 degrees of freedom are given. Different methods in the literature are examined to select the controller and the "Impedance Control Method" which may be suitable for a desired task is selected and the simulation works are done. Robot arm has been modelled using Solidworks® program and the model transferred to the MATLAB® Simulink interface through with SimMechanics toolbox. Simulation studies have been carried out on the Simulink model and the results have been evaluated.

Friction stir welding (FSW) joins materials by plunging a rotating tool into the work piece. The tool consists of a shoulder and a pin that plastically deforms the parent materials and then forges them together under the applied pressure. To create the pressure needed for forging, a rather large axial force must be maintained on the tool. Maintaining this axial force is challenging for robots due to their limited load capacity and compliant nature. To address this problem, force control has been used, and historically, the force has been controlled by adjusting the plunge depth of the tool into the work piece. This paper develops the use of tool traverse speed as the controlling variable instead of plunge depth. To perform this investigation, a FSW force controller was designed and implemented on a retrofitted Milwaukee Model K milling machine. The closed loop proportional, integral plus derivative (PID) control architecture was tuned using the Ziegler–Nichols method. Results show t...

Poultry deboning processing is one of the largest employers of people in the United States. It involves mainly manual processes with only limited use of fixed automation. The main difficulty in this task is the unstructured nature of the task due to the natural variability of birds' size and deformable bodies. To increase product safety and quality, the industry is

Patanjali, foremost exponent of Yoga, described pranayama as the gradual unforced cessation of breathing. Pranayama is derived from two Sanskrit words-prana (life) or yama (control). Pranayam or control of prana or life force yields heart beat pulse and mind control. Yoga combines scientific technique of right behavior (Yama-Niyama), proper posture (asana), life force control (pranayama), interiorisation of the mind (pratyahara),

PurposeAims to discuss how impedance‐controlled parallel robots can effectively perform industrial assembly tasks.Design/methodology/approachA new purely translational parallel robot has been designed to fulfil the requirements of industrial assembly tasks. The kinematic and dynamic models of the robot have been obtained in analytic form. A full‐scale prototype has been realized within the Italian research programme PRIDE (Parallel Robots Interacting with Dynamic Environments). An impedance control algorithm based on the kinematic and dynamic models has been implemented on the control unit of the PRIDE prototype. The effectiveness of the impedance‐controlled PKM has been evaluated performing the assembly of white goods components.FindingsThe test results show that the combined use of impedance control and dynamic compensation applied to parallel kinematics machines allows to reduce remarkably the operational time compared to the currently used position‐controlled industrial robots.R...

The geometric approach to the control of internal forces for robotic grasping is explored. Since the manipulation of deformable objects is a frequently occurrence (medical applications, manipulation of rubber and plastic in industry), manipulation systems with significant contact elasticity are studied. The presence of non--negligible compliance at the contacts, implies that the object dynamics cannot be neglected when attempting to control internal forces without affecting the object position. A geometric approach to derive a control law decoupling the internal force control action from the object dynamics is proposed. 1 Introduction In robotic literature terms as "whole--arm" and "enveloping " or "power" grasps are representative of all those situations where the manipulator touches the gripped object with its own inner parts and not only with the end--effectors, cf. [11, 4, 12] and references therein. In order to execute power grasps, robotic manipul...