Bulanık mantıklı sınır tabakası kalınlığı ayarlaması ile kayan kipli robot kontrolü

Kontrol sinyalindeki çatırtı kayan kipli kontrol uygulamalarında önemli bir sorundur. Sınır tabakası yaklaşımı, çatırtıyı önlemek için, literatürdeki birçok düzenlemeden biridir. Bu yöntemde, süreksiz kayan kipli kontrol yerine, yüksek kazanımlı geri besleme control yasası kullanılmıştır. Sınır tabaka kalınlığı önemli bir tasarım parametresidir. Bu bildiri, sistemin çatırtı olmadan en iyi performansı göstermesi için, sınır tabaka kalınlığını çevrimiçi bir bulanık mantık kullanarak ayarlama yöntemini önermektedir. Bu metod kontrol sinyalindeki çatırtının ölçümünü gerektirmektedir. Bildiri, iki serbestlik dereceli, doğrudan tahrikli bir robot kolu üzerinde yapılan deneyleri de içermektedir

Image based visual servoing using algebraic curves applied to shape alignment

Visual servoing schemes generally employ various image features (points, lines, moments etc.) in their control formulation. This paper presents a novel method for using boundary information in visual servoing. Object boundaries are modeled by algebraic equations and decomposed as a unique sum of product of lines. We propose that these lines can be used to extract useful features for visual servoing purposes. In this paper, intersection of these lines are used as point features in visual servoing. Simulations are performed with a 6 DOF Puma 560 robot using Matlab Robotics Toolbox for the alignment of a free-form object. Also, experiments are realized with a 2 DOF SCARA direct drive robot. Both simulation and experimental results are quite promising and show potential of our new method

Visually aided force control with fuzzy parameter tuning

Vision and force sensors provide rich information which can enable robots to execute complex tasks. The integration of these two types of sensors may prove very useful in many industrial robotic applications, as well as for the robots that operate in environments where humans live. Vision sensors give robots the ability to operate in complex and dynamic environments. With force sensors contacts can be detected, and manipulation tasks can be done without the risk of damaging the workpiece. The integration of vision and force sensing systems equips robots with all these advantages and the abilities of robots can rise dramatically by the integrated use of these sensors. However, this integration is not straightforward. In this thesis, a literature survey about visual servoing and force control is presented firstly. Present integration methods are reported and discussed. A manipulation task is defined as a case study problem. In this problem, a constant magnitude normal force is to be exerted at a fixed point on an object which is free to rotate. Visual servoing and explicit force control techniques are applied next in the task frame formalism to achieve this objective. Disadvantages of the constant parameter controllers are addressed and two solutions in which controller gains are tuned with fuzzy logic systems are presented. The first solution is in the hybrid control category, whereas the second controller is a shared control strategy. These controllers are novel ones; they are the first applications of the fuzzy gain tuning on the integration of vision and force control systems. Experiments are carried out on a two degrees of freedom (DOF) direct drive SCARA type robot and the results obtained with fixed-parameter and fuzzy-tuned control methods are compared. The experimental results show that using fuzzy gain scheduling for the integration of force and vision systems improves the performance of combined controller and also prevents possible causes of instability

Bulanık Parametre Ayarlamalı Görüntü Destekli Kuvvet Kontrolü

Görüntü ve kuvvet sensörleri, robot kontrolünde kullanılabilecek zengin içerikli veriler sunmaktadırlar. Bu verilerin birlestirilerek kullanılması robotların bir çok karmasık görevde basarımlarını arttırabilir. Bu bildiri öncelikle özel bir robot konum ve kuvvet kontrol problemini tanımlamaktadir. Bu problem sabit büyüklükteki bir referans kuvvetinin, dönmeye serbest bırakılmıs bir is parçası üzerine dik yönde uygulanmasını içerir. Bu problemin çözümünde, ilk olarak görüntü tabanlı hibrit konum/kuvvet kontrol yöntemi denenmistir. Bu yöntemde sabit kazanç parametrelerinin kullanımasından kaynaklanan güçlüklere dikkat çekilmis ve parametrelerinin ayarlanmasında bulanık mantık kullanılan hibrit yapıda bir kontrol sistemi önerilmistir. Sabit parametreli ve bulanık mantık parametre ayarlamalı kontrol yöntemleri doğrudan tahrikli SCARA tipindeki bir robot üzerinde denenmis ve sonuçlar karsılastırılmıstır

Fuzzy boundary layer tuning for sliding mode systems as applied to the control of a direct drive robot

Chattering in the control signal is a significant problem in sliding mode control (SMC). The boundary layer approach is one of the many modifications proposed in the literature to avoid the chattering. In this approach, instead of the discontinuous sliding mode control, a continuous feedback control law is employed in a boundary layer around the sliding surface. The thickness of the boundary layer is an important design parameter. This paper proposes a fuzzy online tuning method to adjust the boundary layer thickness for the best system performance without chattering. The method features the measurement of the chattering in the control signal. The paper validates the performance of the algorithm by experiments on a direct drive robot with a range of different payloads

Fuzzy Boundary Layer Tuning as Applied to the Control of a Direct Drive Robot

Chattering in the control signal is a significant problem in sliding mode control applications. The boundary layer approach is one of the many modifications proposed in the literature to avoid the chattering. In this approach, instead of the discontinuous sliding mode control, a high gain feedback control law is employed. The thickness of the boundary layer is an important design parameter. This paper proposes a fuzzy on-line tuning method to adjust the boundary layer thickness for the best system performance without chattering. The method features the measurement of the chattering in the control signal. Experimental results with a two degrees of freedom direct drive robot arm are presented