IEEE/ASME Transactions on Mechatronics

The quality of wafer production in semiconductor manufacturing cannot always be monitored by a costly physical measurement. Instead of measuring a quantity directly, it can be predicted by a regression method (virtual metrology). In this paper, a survey on regression methods is given to predict average silicon nitride cap layer thickness for the plasma-enhanced chemical vapor deposition dual-layer... View full abstract»

A nonlinear piezoelectric amplification mechanism utilizing structural buckling is presented, and its static and dynamic properties are measured and analyzed. Buckling is a pronounced nonlinear effect that occurs at a structurally singular point. A small piezoelectric displacement on the order of 10 μm results in a large buckling displacement on the order of millimeter. Furthermore, the usable str... View full abstract»

This paper describes a framework for controlling a heterogeneous wireless robotic network consisting of aerial and ground vehicles. By use of the term heterogeneous, we imply the synergy of multiple robotic platforms characterized by different dynamics and specialized sensing capabilities. Two main scenarios concerning wireless communications are presented: 1) a decentralized connectivity strategy... View full abstract»

The conversion of mechanical vibration to electrical energy has shown great promise for extending battery life of smart sensor wireless devices for various engineering applications. This paper presents novel analytical models of a piezoelectric bimorph, using the closed-form boundary value (CFBV) method, for predicting the electromechanical power harvester frequency response. The derivations of th... View full abstract»

Interaction with virtual or teleoperated environments requires contact with objects on a multipoint level. We describe the design of a pinch-grasp hand interface device for use as a grasping mechanism to complement haptic interfaces. To preserve a suitable level of transparency for human-computer interaction, this novel interface is designed for high-resolution contact forces, while centered aroun... View full abstract»

This paper presents the actuator with adjustable stiffness (AwAS-II), an enhanced version of the original realization AwAS. This new variable stiffness actuator significantly differs from its predecessor on the mechanism used for the stiffness regulation. While AwAS tunes the stiffness by regulating the position of the compliant elements along the lever arm, AwAS-II changes the position of the lev... View full abstract»

This paper presents the development of a novel adaptive wearable ankle robot for the treatments of ankle sprain through physical rehabilitation. The ankle robot has a bioinspired design, devised after a careful study of the improvement opportunities in the existing ankle robots. Robot design is adaptable to subjects of varying physiological abilities and age groups. Ankle robot employs lightweight... View full abstract»

This paper describes a controller design method for the inertially stabilized system of a tracking radar. Its aim is to track a reference target trajectory with high accuracy while isolating rigid body rotational motions of a host ship. First, we investigate the trajectory generation problem to make the control input for a target tracking on the moving base. Second, dynamic equations of motion are... View full abstract»

Tracking control of piezoelectric actuators (PEAs) has stimulated the development of various advanced control schemes that utilize the feedback of PEA system states for improved control performance. Among them, the one based on the concept of sliding mode has been shown promising due to its robustness to matched uncertainties, but leaving the required state estimation to be desired. Previous studi... View full abstract»

In this paper, a systematic design based on the robust control theory is developed for a microelectromechanical systems nanopositioning/probing device. The device is fabricated on a silicon-on-insulator substrate, and provides decoupled XY motion by using a parallel kinematics mechanism design. Each axis of the device is actuated by linear comb-drives and the corresponding displacements are sensed... View full abstract»

This paper proposes and experimentally validates a method for driving flapping wings at large wing strokes and high frequencies with a DC motor, based on direct, elastic transmission. The DC motor undergoes reciprocating, rather than rotary, motion avoiding the use of nonlinear transmissions such as slider-crank mechanisms. This is key to compact, easy to fabricate, power efficient, and controllab... View full abstract»

This paper presents a novel approach to force sensing by integrating prismatic-tip optical fibers with an orthoplanar spring structure. The complete force sensing solution integrating the prismatic-tip-based sensing concept with an orthoplanar spring mechanism to convert applied forces into a well-delivered displacement whose magnitude can be measured using the optical sensing technique is introdu... View full abstract»

Finger impairment following stroke results in significant deficits in hand manipulation and the performance of everyday tasks. While recent advances in rehabilitation robotics have shown promise for facilitating functional improvement, it remains unclear how best to employ these devices to maximize benefits. Current devices for the hand, however, lack the capacity to fully explore the space of pos... View full abstract»

An instrumented walking aid, the iWA system, has been developed to measure kinematic and kinetic properties of walking aid (WA) use and deliver feedback to improve gait. The clinical requirements, technical specification and design of the system are developed through clinical collaboration. The development of the system is described, including hardware components and data analysis used to process ... View full abstract»

This paper presents a viable quaternion-based complementary observer (CO) that is designed for rigid body attitude estimation. We claim that this approach is an alternative one to overcome the limitations of the extended Kalman filter. The CO processes data from a small inertial/magnetic sensor module containing triaxial angular rate sensors, accelerometers, and magnetometers, without resorting to... View full abstract»

This paper describes an efficient method for scheduling an energy-consuming sensor sparingly in combination with an on-off controller, specifically for a finite horizon control problem in which only end states are critical. In certain low-power applications, such as autonomous microrobotics, on-off controllers can be very efficient in operating piezoelectric actuators (and other capacitive actuati... View full abstract»

A systematic method for nonlinear analysis, design, and estimation in the frequency domain is proposed in this study using a new concept-nonlinear characteristic output spectrum (nCOS). The nCOS function is an analytical and explicit expression for the relationship between nonlinear output spectrum and system characteristic parameters of interest (including frequency, nonlinear parameters, and exc... View full abstract»

In this paper, a self-mixing interferometry sensor has been used as a proximity probe to measure possible runout in permanent magnet synchronous motors, for fault diagnosis. A general procedure for the measurement of the 2-D trajectory of the motor shaft is described in detail, including procedures for the characterization of the uncertainty due to the shape of the shaft, and the management of spe... View full abstract»

Robotic models have been used as one of the approaches to study fish locomotion. Therefore, this paper proposes an effective control scheme that enables robotic models to mimic fin-ray undulation kinematics of live fish. We found in the experiments of robotic fin undulation that the difference between the desired and actual trajectories can be significant. It is believed that the difference might ... View full abstract»

Moving magnet actuators (MMAs) are direct-drive, single-phase electromagnetic linear actuators that provide frictionless and backlash-free motion over a range of several millimeters. This paper investigates the feasibility of using MMAs to simultaneously achieve large range, high speed, and high motion quality in flexure-based nanopositioning systems. Component and system level design challenges a... View full abstract»

This paper presents design and digital implementation of a fuzzy controller for achieving improved performance of Brushless dc (BLDC) servomotor drive. The performance of fuzzy and PID controller-based BLDC servomotor drives is investigated under different operating conditions such as change in reference speed, parameter variations, load disturbance, etc. BLDC servomotors are used in aerospace, in... View full abstract»

This paper reports on the system design for integrating the various processes needed for end-to-end implementation of a smart assistive robotic manipulator. Specifically, progress is reported in the empowerment of the UCF-MANUS system with a suite of sensory, computational, and multimodal interface capabilities so that its autonomy can be made accessible to users with a wide range of disabilities.... View full abstract»

This paper presents a stable inversion of nonminimum phase systems with highly efficient computation for high-sampling rate applications. The stable filter that inverts the dynamics of a nonminimum system is based on cascading a stable pole-zero cancellation infinite impulse response (IIR) filter with a high-order finite impulse response (FIR) filter which inverts the unstable zero dynamics. The h... View full abstract»