In this paper control systems design approach, based on siding mode methods, that allows maintain some functional relation - like bilateral or multilateral systems, establishment of virtual relation among mobile robots or control of haptic systems - is presented. It is shown that all basic motion control problems - trajectory tracking, force control, hybrid position/force control scheme and the impedance control for the interacting systems- can be treated in the same way while avoiding the structural change of the controller and guarantying stable behavior of the system In order to show applicability of the proposed techniques simulation and experimental results for high precision systems in microsystems assembly tasks are presented..

In this work, we suggested a new approach for the control of a mobile robot capable of being a building block of an intelligent agent. This approach includes obstacle avoidance and goal tracking implemented as two different sliding mode controllers. A geometry based behavior arbitration is proposed for fusing the two outputs. Proposed structure is tested on simulations and real robot. Results have confirmed the high performance of the method.

This article provides in-depth knowledge about our undergoing effort to develop an open architecture micromanipulation system with force sensing capabilities. The major requirement to perform any micromanipulation task effectively is to ensure the controlled motion of actuators within nanometer accuracy with low overshoot even under the influence of disturbances. Moreover, to achieve high dexterity in manipulation, control of the interaction forces is required. In micromanipulation, control of interaction forces necessitates force sensing in milli-Newton range with nano-Newton resolution . In this paper, we present a position controller based on a discrete time sliding mode control architecture along with a disturbance observer. Experimental verifications for this controller are demonstrated for 100, 50 and 10 nanometer step inputs applied to PZT stages. Our results indicate that position tracking accuracies up to 10 nanometers, without any overshoot and low steady state error are achievable. Furthermore, the paper includes experimental verification of force sensing within nano-Newton resolution using a piezoresistive cantilever end- effector. Experimental results are compared to the theoretical estimates of the change in attractive forces as a function of decreasing distance and of the pull off force between a silicon tip and a glass surface, respectively. Good agreement among the experimental data and the theoretical estimates has been demonstrated.

This paper presents an experimental comparison of conventional (calibrated and uncalibrated) image based visual servoing methods in various microsystem applications. Both visual servoing techniques were tested on a microassembly workstation, and their regulation and tracking performances are evaluated. Calibrated visual servoing demands the optical system calibration for the image Jacobian estimation and if a precise optical system calibration is done, it ensures a better accuracy, precision and settling time compared with the uncalibrated approach. On the other hand, in the uncalibrated approach, optical system calibration is not required and since the Jacobian is estimated dynamically, it is more flexible.

In this work, analog application for the Sliding Mode Control (SMC) to piezoelectric actuators (PEA) is presented. DSP application of the algorithm suffers from ADC and DAC conversions and mainly faces limitations in sampling time interval. Moreover piezoelectric actuators are known to have very large bandwidth close to the DSP operation frequency. Therefore, with the direct analog application, improvement of the performance and high frequency operation are expected. Design of an appropriate SMC together with a disturbance observer is suggested to have continuous control output and related experimental results for position tracking are presented with comparison of DSP and analog control application.

Accurate position-tracking control in a belt-driven servomechanism can experience vibrations and large tracking errors due to compliance and elasticity introduced by force transmission through the belt and nonlinear-friction phenomenon. In this paper, a new control algorithm which is based on a sliding-mode control that is able to deal with these problems is proposed. In order to further optimize position-tracking performance, the control scheme has been extended by an asymptotic disturbance observer. It has been proven that robust and vibration-free operation of a linear-belt-driven system can be achieved. The experiments presented in this paper show improved position-tracking error response while maintaining vibration suppression.

In general, mechatronics systems have no standard operating system that could be used for planning and control when these complex devices are running. The goal of this paper is to formulate a work platform that can be used as a method for obtaining precision in the manipulation of micro-entities using micro-scale manipulation tools for microsystem applications. This paper provide groundwork for motion planning and assembly of the Micro-Assembly Workstation (MAW) manipulation system. To demonstrate the feasibility of the idea, the paper implements some of the motion planning algorithms; it investigates the performance of the conventional Euclidean distance algorithm (EDA), artificial potential fields’ algorithm, and A* algorithm when implemented on a virtual space.

A hybrid force-position controller based man-machine interface for manipulation of micro objects through pushing with a micro cantilever is presented. Visual feedback is employed to detect position and orientation of a micro particle and a piezoresistive AFM cantilever is automatically positioned to align the line of action of interaction forces in a way that will ensure the particle to track a desired trajectory. Control of the interaction force is delegated to a human operator through scaled bilateral teleoperation. A custom tele-micromanipulation setup is built for testing and preliminary experiments of controlled pushing to achieve pure translational motion of rectangular micro objects are implemented.

Design of a motion control system should take into account both the unconstrained motion performed without interaction with environment or another system, and the constrained motion where the system is in contact with environment or has certain functional interactions with another system. In this paper control systems design approach, based on siding mode methods, that allows selection of control for generic tasks as trajectory and/or force tracking as well as for systems that require maintaining some functional relation—like bilateral or multilateral systems, establishment of virtual relation among mobile robots or control of haptic systems—is presented. It is shown that all basic motion control problems—trajectory tracking, force control, hybrid position/force control scheme and the impedance control—can be treated in the same way while avoiding the structural change of the controller and guaranteeing stable behaviour of the system. In order to show applicability of the proposed techniques simulation and experimental results for high precision systems in microsystems assembly tasks and bilateral control systems are presented. Copyright © 2007 John Wiley & Sons, Ltd.

In this paper, an open-architecture, reconfigurable microassembly workstation for efficient and reliable assembly of micromachined parts is presented. The workstation is designed to be used as a research tool for investigation of the problems in microassembly. The development of such a workstation includes the design of: (i) a manipulation system consisting of motion stages providing necessary travel range and precision for the realization of assembly tasks, (ii) a vision system to visualize the microworld and the determination of the position and orientation of micro components to be assembled, (iii) a robust control system and necessary mounts for the end effectors in such a way that according to the task to be realized, the manipulation tools can be easily changed and the system will be ready for the predefined task. In addition tele-operated and semi-automated assembly concepts are implemented. The design is verified by implementing the range of the tasks in micro-parts manipulation. The versatility of the workstation is demonstrated and high accuracy of positioning is shown.

In this work, analog application for the sliding mode control (SMC) of piezoelectric actuators is presented. DSP application of the algorithm suffers from ADC and DAC conversions and faces speed limitations. Moreover, piezoelectric actuators are known to have very large bandwidth close to the DSP operation frequency. Therefore, with the direct analog application, improvement of the performance is expected and high frequency operation will be achieved. First an appropriate SMC is designed to have continuous control output and then experimental results for position tracking using DSP and analog application are presented for comparison.

Design of a motion control system should take into account (a) unconstrained motion performed without interaction with environment or other system, and (b) constrained motion with system in contact with environment or another system or has certain functional interaction with another system. Control in both cases can be formulated in terms of maintaining desired system configuration what makes essentially the same structure for common tasks: trajectory tracking, interaction force control, compliance control etc. It will be shown that the same design approach can be used for systems that maintain some functional relation - like bilateral or multilateral systems, relation among mobile robots or control of haptic systems.

Design of motion control systems should take into account (a) unconstrained motion performed without interaction with environment or other systems, (b) constrained motion performed by certain functional interaction with environment or other system. Control in both cases can be formulated in terms of maintaining desired system configuration what makes essentially the same structure for common tasks: trajectory tracking, interaction force control, compliance control etc. It will be shown that the same design approach can be used for systems that maintain some functional relations like parallel robots. Copyright © 2007 IFAC

In this paper, a method that allows for the merger of the good features of sliding-mode control and neural network (NN) design is presented. Design is performed by applying an NN to minimize the cost function that is selected to depend on the distance from the sliding-mode manifold, thus providing that the NN controller enforces sliding-mode motion in a closed-loop system. It has been proven that the selected cost function has no local minima in controller parameter space, so under certain conditions, selection of the NN weights guarantees that the global minimum is reached, and then the sliding-mode conditions are satisfied; thus, closed-loop motion is robust against parameter changes and disturbances. For controller design, the system states and the nominal value of the control input matrix are used. The design for both multiple-input-multiple-output and single-input-single-output systems is discussed. Due to the structure of the (M)ADALINE network used in control calculation, the proposed algorithm can also be interpreted as a sliding-mode-based control parameter adaptation scheme. The controller performance is verified by experimental results