Investigation of haptic manipulators with linear equations of motion

Kızılbey, Aras
In this thesis, linearization of the equations of motion of haptic interfaces and the effects of such linearization on haptic applications are examined. Three and six DOF configurations of the Phantom Premium™ 1.5 have been selected as the haptic manipulators to be investigated. By utilizing the generic computer code that has been developed for hybrid manipulators composed of revolute and prismatic joints, the equations of motion for the aforementioned two haptic manipulator types are derived in symbolic form. Using the concept of Linearity Number (LN), linearization of the equations of motion of the three and six DOF haptic interfaces have been attempted. It has been already shown that there exist completely linear three DOF serial spatial manipulators. Since Phantom Premium 1.5 contains a parallelogram mechanism, however, it is a hybrid manipulator. To the author’s knowledge, the existence of linear six DOF spatial manipulators, on the other hand, is uncertain. In this study, complete linearization of the three DOF haptic interface is achieved. To the author’s knowledge, such a result does not exist in the literature. Furthermore, non-existence of fully linear equations of motion for the selected six DOF configuration is shown. The effects of linearization on the performance of three DOF haptic interfaces are investigated by considering two performance criteria of a haptic interaction which are Stable Impedance Range and Transparency Bandwidth. Mathematical models and specific simulation environments are formed for Stable Impedance Range and Transparency Bandwidth simulations. The numerical values of these two performance criteria are calculated via simulations. The relationship between the aforementioned performance criteria and the degree of linearity of the haptic manipulator is also investigated.


Utilization of motor current based torque feedback to improve the transparency of haptic interfaces
Baser, Ozgur; Konukseven, Erhan İlhan (2012-06-01)
In this paper motor current based torque feedback compensator is utilized in actuator space together with a closed loop impedance control algorithm instead of model based compensator to improve the transparency performance of haptic interfaces; moreover, a novel transparency evaluation metric is developed to evaluate the transparency performance of these devices. The proposed control algorithm is experimentally tested on a 1 DOF haptic device by employing a low-cost current sensor. It is also tested on a MA...
Experimental evaluation of cable drum systems as linear motion sensors
KILIÇ, ERGİN; Dölen, Melik; Koku, Ahmet Buğra (2011-04-15)
This study evaluates cable-drum mechanisms as linear motion sensors for certain CNC applications. In this work, the dynamical attributes of a generic device are studied experimentally. The conducted research indicates that despite the significant traction force induced between the cable and its drum, small fluctuations in mechanism's speed yields a considerable (micro) slip at the interface.
Classification in Frequency Domain of EEG Signals of Motor Imagery for Brain Computer Interfaces
Halıcı, Uğur (2009-05-22)
In this study the classification of the EEG signals recorded during motor imagery for curser movement in brain computer interfaces is examined, in which the feature vectors obtained in frequency domain is used and then the linear transformations are applied for reducing the size of the feature vectors.
Transparency improvement in haptic devices with a torque compensator using motor current
Baser, Ozgur; Konukseven, Erhan İlhan; Gurocak, Hakan (2012-12-01)
Transparency of a haptic interface can be improved by minimizing the effects of inertia and friction through the use of model based compensators. However, the performance with these algorithms is limited due to the estimation errors in the system model and in the velocity and acceleration from quantized encoder data. This paper contributes a new torque compensator based on motor current to improve transparency. The proposed method was tested experimentally in time and frequency domains by means of an excita...
Investigation of effect of design and operating parameters on acoustophoretic particle separation via 3D device-level simulations
Sahin, Mehmet Akif; ÇETİN, BARBAROS; Özer, Mehmet Bülent (Springer Science and Business Media LLC, 2019-12-16)
In the present study, a 3D device-level numerical model is implemented via finite element method to assess the effects of design and operating parameters on the separation performance of a microscale acoustofluidic device. Elastodynamic equations together with electromechanical coupling at the piezoelectric actuators for the stress field within the solid parts, Helmholtz equation for the acoustic field within fluid, and Navier-Stokes equations for the fluid flow are coupled for the simulations. Once the zer...
Citation Formats
A. Kızılbey, “Investigation of haptic manipulators with linear equations of motion,” Thesis (M.S.) -- Graduate School of Natural and Applied Sciences. Mechanical Engineering., Middle East Technical University, 2019.