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Mechatronics, IEEE/ASME Transactions on

Issue 1 • Date March 2002

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Displaying Results 1 - 12 of 12
  • Comments on "Magnetically levitated micro PM motors by two types of active magnetic bearings"

    Page(s): 99 - 100
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (181 KB) |  | HTML iconHTML  

    This note clarifies the design of proportional derivative (PD) controllers for the magnetic levitation systems of micro permanent magnet (PM) motors proposed in the original paper of Komori and Yamane (ibid., vol.6, p.43-9, 2001). It is shown that the PD controllers cannot stabilize the described levitated micro motors because it is necessary to use other values of parameters for these controllers. We present necessary and sufficient conditions for the stability of the controlled systems described in the paper. View full abstract»

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  • Hybrid control of the Pendubot

    Page(s): 79 - 86
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (297 KB)  

    Swing up and balance control are two interesting control problems for the Pendubot. Many studies have been conducted for swing up control of the Pendubot. A few results have been reported for feedback stabilization of the Pendubot. In this paper, we apply a new hybrid controller for feedback stabilization of the Pendubot. It is well-known that it is impossible to use smooth feedback to stabilize a class of underactuated mechanical systems around their equilibra, even locally. Various nonsmooth controllers have been presented for feedback stabilization of this type of system. However, most of the studies are either based on theoretical proofs or simulations. There is a strong need for experimental study. The Pendubot arises as a special test bed for this purpose. This experimental study has a particular interest for feedback stabilization of underactuated mechanical systems that are not feedback stabilizable using smooth control View full abstract»

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  • Optimization and implementation of multimode piezoelectric shunt damping systems

    Page(s): 87 - 94
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (345 KB)  

    Piezoelectric transducer (PZT) patches can be attached to a structure in order to reduce vibration. The PZT patches essentially convert vibrational mechanical energy into electrical energy. The electrical energy can be dissipated via an electrical impedance. Currently, impedance designs require experimental tuning of resistive circuit elements to provide optimal performance. A systematic method is presented for determining the resistance values by minimizing the H2 norm of the damped system. After the design process, shunt circuits are normally implemented using discrete resistors, virtual inductors and Riordian gyrators. The difficulty in constructing the shunt circuits and achieving reasonable performance has been an ongoing and unaddressed problem in shunt damping. A new approach to implementing piezoelectric shunt circuits is presented. A synthetic impedance, consisting of a voltage controlled current source and a digital signal processor system, is used to synthesize the terminal impedance of a shunt network. A two-mode shunt circuit is designed and implemented for an experimental simply supported beam. The second and third structural modes of the beam are reduced in magnitude by 22 and 18 dB View full abstract»

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  • Design and control of a microrobotic system using magnetic levitation

    Page(s): 1 - 14
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (534 KB) |  | HTML iconHTML  

    Presents a prototype microrobot based on magnetic principles. Miniature items are to be transported and assembled in hazardous environments. A microrobot can be remotely operated with 3 DOF in an enclosed environment by transferring magnetic energy and optical signals from outside. The magnetic drive unit consists of 8 electromagnets (4 pairs), 2 permanent magnets, a return yoke and a pole piece. The microrobot is manipulated under the pole piece by regulating magnetic field. It consists of a magnetic head, a body (electronic circuit and batteries), and copper alloy ribbon ringers. A shape memory alloy actuator activates the fingers by illuminating/extinguishing several LED. PID controls were applied. To cope with uncertainties and variations in payload masses, an adaptive control law was also employed for positioning along the z axis to enable the controller parameters to be adjusted in real-time. Effectiveness of the control was verified by the results of several experiments. The microrobot has a net mass of 8.1 g and it can elevate and manipulate objects with masses up to 1.5 g within a volume of 29×29×26 mm3 with a precision of 0.05 mm View full abstract»

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  • Modeling and design of flexure jointed Stewart platforms for control purposes

    Page(s): 95 - 99
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (285 KB) |  | HTML iconHTML  

    A number of researchers have been investigating the use of Stewart platforms (or hexapods) for precision applications including machining, vibration isolation and precise pointing. To avoid friction and backlash, these hexapods often employ flexure joints. This does eliminate nonlinear friction and backlash, but adds linear spring/damper dynamics. In addition, since the motion is so accurate, base and/or payload vibrations become significant disturbances to suppress. This paper develops guidelines for designing the flexure joints to facilitate closed-loop control. In addition, since base accelerations are typically the dominant disturbance, their effect is derived. Unlike most prior hexapod dynamic formulations, the model is experimentally verified View full abstract»

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  • Design and control of a disk-type integrated motor-bearing system

    Page(s): 15 - 22
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (322 KB) |  | HTML iconHTML  

    A disk-type integrated motor-bearing system having axial magnetic flux is newly invented and its design, analysis, and control methods are presented. Sinusoidal motoring currents to four symmetrically placed winding groups produce a torque, whereas control currents of the same magnitude but opposite signs added to the opposite winding groups create radial forces. The control currents are intended to break force symmetry, resulting in unbalanced radial forces. The system employs two stators not only to effectively remove the rotational frequency modulation effect in the radial control forces, but also to reduce the torque ripple. It is shown that the prototype integrated motor-bearing system built in the laboratory succeeds in stable radial direction control and operation of the rotor View full abstract»

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  • Integrating embedded PC and Internet technologies for real-time control and imaging

    Page(s): 52 - 60
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (298 KB) |  | HTML iconHTML  

    The use of embedded personal computing (PC) technology allows desktop computer applications to evolve into the real-time control world. Such systems will be compact, reliable and low in cost. However, the mainstream PC platforms such as Windows NT have shortcomings concerning their real-time capabilities. The integration of embedded PC and Internet technologies make distributed real-time control a reality and eliminate the limitations of PC operating systems (OS). This paper discusses the general hardware, OS and software development tools for distributed, Internet-enabled, PC-based embedded control systems. A specific application of the approach is discussed, the development of a long-reach manipulator system for highway maintenance operations, which verifies the approach and illustrates its potential applicability View full abstract»

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  • Manipulating rigid payloads with multiple robots using compliant grippers

    Page(s): 23 - 34
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (454 KB) |  | HTML iconHTML  

    This paper describes an approach to nonmodel-based decentralized controls of multirobot systems utilizing structural flexibility in gripper design to avoid large unwanted internal forces acting on multirobot systems. It is proven in theory that a simple proportional and derivative (PD) position feedback plus gravity compensation controller can regulate the desired position/orientation of a payload manipulated by multiple robots with compliant grippers and simultaneously damp vibrations of compliant grippers. By adding a force feedforward control to the PD scheme, a hybrid position/force control scheme is further developed to control internal forces between robots and the payload in the particular directions, in the event that the compliance of grippers is low or negligible in these directions. Experiments conducted with two CRS A460 industrial robots manipulating a beam, using a rigid and a compliant gripper, confirm these theoretical predictions View full abstract»

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  • Estimation of the contouring error vector for the cross-coupled control design

    Page(s): 44 - 51
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (299 KB) |  | HTML iconHTML  

    In biaxial motion systems, applying the cross-coupled control (CCC) significantly improves contouring accuracy for linear and circular contours. As geometrical and parametric curves become more popular in modern manufacturing, machining processes with multiaxis motion systems are required, however, the available biaxial CCC cannot be directly applied to arbitrary contours with multiaxis machining systems. In this paper, we propose a novel approach for arbitrary contours by estimating the contouring error vector to efficiently determine the variable gains for CCC. Experimental results for a biaxial motion system indicate that the proposed approach efficiently yields variable gains similar to those in traditional CCC. Furthermore, results on a three-axis CNC machining center show that the present approach significantly improves motion accuracy in multiaxis motion systems View full abstract»

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  • Comparison of the dynamic response of radial and tangential magnetic flux thrust bearings

    Page(s): 61 - 66
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (284 KB) |  | HTML iconHTML  

    Theoretical predictions were made for the dynamic performance of a tangential flux magnetic thrust bearing. A prototype bearing was built with the stators and rotors made from tape wound strip. The performance of this bearing was measured and compared to the theoretical predictions and also to the performance of a radial flux thrust bearing. Tangential flux bearings are intrinsically amenable to construction from tape wound cores. Tape wound cores come in high saturation alloys like supermenduer which can give the bearing a high force to size ratio. The thin tape laminates give the bearing a broad frequency bandwidth. By comparison the paper shows that it is difficult to make a laminated rotor magnetically efficient for radial flux bearings. A test rig is described that was built to measure the performance of the tangential flux bearing. A power amplifier with current feedback provides DC and harmonic currents to the coils. A load cell was built into the test rig to measure the axial thrust, an inductive/Hall sensor was included to measure the coil current, and a Hall probe was used to measure the gap flux View full abstract»

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  • Ultra precision motion control of a multiple degrees of freedom magnetic suspension stage

    Page(s): 67 - 78
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (408 KB)  

    A general framework for ultra precision motion control of magnetic suspension actuation systems with large travel ranges in multiple degrees of freedom (DOF) is presented. It encompasses the development of nonlinear electromagnetic force model for 6-DOF actuation, and the design of the necessary control architecture for ultra precision motion control of magnetic suspension actuation systems. A 6-DOF magnetic suspension stage (MSS) was designed and fabricated to illustrate the developed framework. The MSS consists of multiple electromagnets that are located around the flotor and are utilized to suspend and modulate its position and orientation. The control architecture takes the six control parameters provided by a laser measuring system and intends to control the 6-DOF motion by regulating the current in the electromagnets. The developed robust nonlinear control architecture consists of three components: 1) feedback linearization; 2) force distribution; and 3) H robust controllers for each DOF of motion. Several experiments are designed to illustrate the desired characteristics of the developed system View full abstract»

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  • Study on a novel contact-free planar system using direct drive DC coils and permanent magnets

    Page(s): 35 - 43
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (367 KB) |  | HTML iconHTML  

    To cope with the severe specification such as a concurrent realization of high accuracy and wide operating range demanded in many fields, we suggest a contact-free planar system that realizes the spatial motion of a plate by generating a levitation force and a thrust force at the same plane concurrently. The system utilizes an interaction between the direct drive DC coils of a common shape and the permanent magnets with a coincident polar direction and, thus, it is very easy to implement and simple to quantify the magnetic interaction. We discuss a driving principle of the planar system including magnetic force generation mechanism, a framework for the force model, governing characteristics of the levitated plate and a planar motion control of the constructed prototype. The experimental results are given to verify the derived theoretical model and the feasibility of the system View full abstract»

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Aims & Scope

IEEE/ASME Transactions on Mechatronics encompasses all practical aspects of the theory and methods of mechatronics, the synergetic integration of mechanical engineering with electronic and intelligent computer control in the design and manufacture of industrial products and processes.

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Meet Our Editors

Editor-in-Chief
Okyay Kaynak
Department of Electrical and Electronic Engineering
Bogazici University
34342 Istanbul, Turkey
okyay.kaynak@boun.edu.tr