This work presents functional description of a walking piezoelectric motor and its control in nanometer precision. For this purpose a dynamical model of the actuator is derived based on simple mass spring damper system. Model parameters are estimated from step response plot and the system is expressed with second order transfer function. Additional identification experiments verified the theoretical kinematics of the bimorph legs. These experiments demonstrate approximately linear relation between the legs displacement in x and y directions to the applied voltages. Based on derived system model and identification results a PI controller followed by Hadamard transformation is proposed as a controller scheme. Experimental results for staircase and sinusoidal references reveal precise positioning capabilities of the system with the proposed control scheme down to few nanometers.

This paper presents the design, integration and experimental validation of a miniature light-weight delta robot targeted to be used for a variety of applications including the pick-place operations, high speed precise positioning and haptic implementations. The improvements brought by the new design contain; the use of a novel light-weight joint type replacing the conventional and heavy bearing structures and realization of encoderless position measurement algorithm based on hall effect sensor outputs of direct drive linear motors. The description of mechanical, electrical and software based improvements are followed by the derivation of a sliding mode controller to handle tracking of planar closed curves represented by elliptic fourier descriptors (EFDs). The new robot is tested in experiments and the validity of the improvements are verified for practical implementation.

This paper presents the development and implementation of a new, computer controlled microscope setup targeted to be used as the inspection unit of a microfactory system. The presented design has two degrees of freedom responsible for changing the magnification and focus level over the image respectively. Following the discussion on mechanical design and production, the couplings observed in experiments between magnification and focus levels are analyzed. Originating from the infeasibility of modeling the maximum sharpness point (i.e. maximum focus point) for any arbitrary object, a self optimizing controller structure is proposed that can work for any magnification level set by the user. The proposed controller structure is validated by experiments to restore the maximum focus point while the magnification level is arbitrarily set by the user.

This article presents a kinematic model and control of a galvanometric laser beam steering system for high precision marking, welding or soldering applications as a microfactory module. Galvo systems are capable of scanning laser beam with relatively high frequencies that makes them suitable for fast processing applications. For the sake of flexibility and ease of use 2D reference shapes to be processed are provided as CAD drawings. Drawings are parsed and interpolated to x - y reference data points on MATLAB then stored as arrays in C code. C header file is further included as reference data points to be used by the system. Theoretical kinematic model of the system is derived and model parameters are tuned for practical implementation and validated with respect to measured positions on rotation space with optical position sensor and image field with position sensitive device. Machining with material removal requires high power laser to be employed that makes position measurement on image field unfeasible. Therefore for closed loop applications optical position sensor embedded in galvo motors is used for position feedback. Since the model approved to be approximately linear in the range of interest by simulations, a PI controller is used for precise positioning of the galvo motors. Experimental results for tracking circular and rectangular shape references are proved to be precise with errors of less than 2%.

As technology brings more complex and sophisticated systems, the importance of the problem of designing and developing a mechatronic system increases as well and it becomes more complicated to obtain a reliable, accurate and sustainable system. Since complex systems are generally composed of many different types of sub-systems, a necessity for a systematic approach towards the development arises. In this paper, the problem of software development for complex mechatronic systems is addressed and a novel software framework is proposed in order to provide common design and development criteria and related software structures. As an implementation of the framework and to present a proof of concept, software for a laser micromachining workstation is developed from scratch using this framework. Experiments are conducted using the workstation and results are provided.

Due to their robustness and cost effectiveness, double fed induction generator (DFIG) based wind turbines are becoming very popular in wind energy conversion systems. Robustness of any implemented control structure can easily be lost due to nonlinearities, variations in the DFIG parameters and network voltage failures. In this study, machine parameter dependent terms will be estimated with the first order low pass filter disturbance observer, and stator voltage orientation will be applied in the experimental test bed. DSP ACE DS1103 platform is used as a digital controller.

This work presents functional description of a walking piezoelectric motor and its control in bending mode. For this purpose a dynamical model of the actuator is derived based on simple mass spring damper system. Identification experiments are conducted to verify the theoretical kinematics of the bimorph legs presented in previous works. These experiments demonstrate approximately linear relation between the legs displacement in x and y planes to the applied voltages. Based on these results a PI controller followed by Hadamard transformation is proposed as a controller scheme. Experimental results for staircase and sinusoidal tracking references reveal precise positioning down to few nano-meters.

This paper presents a methodological approach for the practical realization of high precision laser micromachining over shapes of arbitrary geometry. The scheme presented throughout the paper includes an easy-to-use way of reference generation via image processing for shapes that is mathematically difficult to represent. The necessary constraint of tracking the constant reference tangential velocity for high precision laser production is enabled via the so called spline polynomial interpolation method. The description of algorithmic steps for the acquisition of reference cartesian trajectory from an image is followed by the presentation of spline method and the controller used for the realization. The proposed approach is tested in experiments and the validity of the methodology is verified for practical implementation.

A new compliant stage based on 3-PRR kinematic structure is designed to be used as a planar micro positioner. The mechanism is actuated by using piezoelectric actuators and center position of the stage is measured using a dual laser position sensor. It's seen that manufactured mechanism has unpredictable motion errors due to manufacturing and assembly faults. Thus, sliding mode control with disturbance observer is chosen to be implemented as position control in x-y axes of the center of the mechanism. Instead of piezoelectric actuator models, experimental models are extracted for each actuation direction in order to be used as nominal plants for the disturbance observer. The position control results are compared with the previous position control using linear piezoelectric actuator models and it's seen that the implemented control methodology is better in terms of errors in x and y axes. Besides, the position errors are lowered down to ±0.06 microns, which is the accuracy of the dual laser position sensor.

This work focuses on the design of driver for PiezoLegs actuator used for high precision positioning purposes. Motor is driven with the set of periodical voltages with known frequency, amplitude and phase shift between the phases. Motor's operation has been investigated in detail and clear relationships between the amplitude and phase shifts between the phases and motor step size have been established. According to the motor analysis, set of design requirements for the design of driver is given. Particular solution meeting these requirements and satisfying the given design constraints is presented. Driver is experimentally evaluated for power consumption and analyzed in frequency domain, it's performance is compared to the performance of a commercially available driver for the same motor. Designed driver shows improved performance.

This work focuses on the design of adaptive controller for high precision positioning purposes using PiezoLegs actuator. Actuator is driven with the set of periodical sine shaped voltages with known frequency, amplitude and phase shift between the phases. Clear relationships between the amplitude and phase shifts between the phases and actuator step size have been established. Based on these relationships adaptive controller has been designed. Controller is a linear, cascaded type of feedback controller that uses position feedback from an encoder. Based on the information of the absolute error controller performs the adaptive step size modulation by changing amplitude or phase shift of the driving voltages. Proposed algorithm is validated experimentally. Experimental results show satisfactory level performance, controller achieves fast settling time, no overshoot response and high accuracy of positioning with small steady state errors.

A planar parallel compliant mechanism based on 3-RRR kinematic structure is designed to be used as a micro positioning stage. The position of the center is measured by using a laser position sensor and the mechanism is actuated by piezoelectric actuators. The stage displacements are analyzed by using structural Finite Element Analysis (FEA). However the experimental displacement results for the manufactured mechanism are not compatible with the FEA which means that we have errors due to manufacturing, assembly etc. A position control using Sliding Mode Control with Disturbance Observer is proposed for the reference tracking of the center of the stage. Piezoelectric actuator linear models are used for disturbance rejection. Finally, the position control of the mechanism is succeeded although it has inadmissible errors compared to FEA.

Brushless de motor (BLDC motor) is ,In attractive option for variable speed applications. It is more robust than the de motor and the performance is comparable to the de motor. Sliding mode control may be applied to the control of BLDC motor as presented in this paper.

This paper presents a novel functional observer for motion control systems to provide higher accuracy and less noise in comparison to existing observers. The observer uses the input current and position information along with the nominal parameters of the plant and can observe the velocity, acceleration and disturbance information of the system. The novelty of the observer is based on its functional structure that can intrinsically estimate and compensate the un-measured inputs (like disturbance acting on the system) using the measured input current. The experimental results of the proposed estimator verifies its success in estimating the velocity, acceleration and disturbance with better precision than other second order observers.