This article demonstrates that an actuator can be used as a single platform for measurement, control and estimation by designing a chain of estimators and performing simple off-line experiments. Making use of the fact that rejected torque from the dynamical system consists of all the system dynamics beside all external disturbances. The rejected torque waves are estimated using the actuator parameters, and used for an off-line experiment for parameter estimation, then the estimated rejected torque is used along with the estimated parameters to estimate the positions of any multi-degree of freedom flexible dynamical system. That makes it possible to use those estimates to achieve sensorless motion and vibration control without using actual measurement. Moreover, all the estimated parameters and system dynamics can be used in order to estimate any external disturbance on the system when it starts to interact with the environment.

With the miniaturization of products to the levels of micrometers and the recent developments in microsystem fabrication technologies, there arises a great need for an assembly process for the formation of complex hybrid microsystems. Integration of microcomponents, manufactured from different materials using different micro fabrication techniques, is still a primary challenge since some of the fundamental problems originating from the small size of parts to be manipulated, high precision necessity and the physics of the micro world are still not fully investigated. In this book, design and development of an open-architecture and modular microassembly workstation for efficient and reliable assembly of micromachined parts is presented through detailed inspection of the necessities for design and problems which arise as a result of the nature of the microworld. The analysis of the design process will be useful for the investigation of the inevitable technology of near future, microassembly, with the increasing trend towards miniaturization in every aspect of our lives and will be especially helpful to professionals in Microsystems Technologies.

In this paper, the design of a discrete-time sliding-mode controller based on Lyapunov theory is presented along with a robust disturbance observer and is applied to a piezostage for high-precision motion. A linear model of a piezostage was used with nominal parameters to compensate the disturbance acting on the system in order to achieve nanometer accuracy. The effectiveness of the controller and disturbance observer is validated in terms of closed-loop position performance for nanometer references. The control structure has been applied to a scaled bilateral structure for the custom-built telemicromanipulation setup. A piezoresistive atomic force microscope cantilever with a built-in Wheatstone bridge is utilized to achieve the nanonewton-level interaction forces between the piezoresistive probe tip and the environment. Experimental results are provided for the nanonewton-range force sensing, and good agreement between the experimental data and the theoretical estimates has been demonstrated. Force/position tracking and transparency between the master and the slave has been clearly demonstrated after necessary scaling.

In many microassembly applications, it is often desirable to position and orient polygonal micro-objects lying on a planar surface. Pushing micro-objects using point contact provides more flexibility and less complexity compared to pick and place operation. Due to the fact that in micro-world surface forces are much more dominant than inertial forces and these forces are distributed unevenly, pushing through the center of mass of the micro-object will not yield a pure translational motion. In order to translate a micro-object, the line of pushing should pass through the center of friction. In this paper, a semi-autonomous scheme based on hybrid vision/force feedback is proposed to push microobjects with human assistance using a custom built tele-micromanipulation setup to achieve pure translational motion. The pushing operation is divided into two concurrent processes: In one process human operator who acts as an impedance controller alters the velocity of the pusher while in contact with the micro-object through scaled bilateral teleoperation with force feedback. In the other process, the desired line of pushing for the micro-object is determined continuously using visual feedback procedures so that it always passes through the varying center of friction. Experimental results are demonstrated to prove nano-Newton range force sensing, scaled bilateral teleoperation with force feedback and pushing microobjects.

Abstract Abstract This paper presents a sensorless estimation algorithm for estimating flexible system parameters, dynamics and externally applied forces or torques due to system interaction with the environment. The proposed algorithm makes it possible to design a chain of observers that require measuring actuator's current and velocity along with performing two off-line experiments that do not require any additional measurement from the flexible system. The output of these observers are estimates of the system parameters, estimates of the system dynamics in configuration, motion and acceleration level. Eventually, the estimated positions are used to control the motion and vibration of the flexible lumped system without taking any measurement from the system. Experimental results show the validity of the proposed sensorless estimation algorithm and the possibility of controlling motion and vibration of flexible systems by focusing all the measurements on the actuator side keeping the system free from any attached sensors.

This paper demonstrates the feasibility of modeling any dynamical system using a set of fractional order difierential equations, including distributed and lumped systems. Fractional order difierentiators and integrators are the basic elements of these equations representing the real model of the dynamical system, which in turn implies the necessity of using fractional order controllers instead of controllers with integer order. This paper proves that fractional order difierential equations can be used to model any dynamical system whether it is continuous or lumped.

Abstract—In this paper we present a wave based control approach for flexible structures using the actuator as a single platform for measurement and control without picking any measurements from the system. using the reflected wave to the actuator from the system along with the actuator parameters as the current and velocity to estimate the flexible system’s parameters. and using those estimated parameters to achieve robust controllers keeping the system free from any measurements and attached sensors. in this paper all the sensors attached to the system were used just to verify the performance of the controller not to have feed back from the system.

SURALP is a new walking humanoid robot platform designed at Sabanci University - Turkey. When completed, the kinematic arrangement of the robot will consist of 30 independently driven axes, including legs, arms, waist and a neck. Up to now, the 12-degrees-of-freedom (DOF) leg module of the platform, SURALP-L, is built. This paper presents the highlights of the design of this leg module. Mechanical design, actuation mechanisms, sensors, the control hardware and algorithms are introduced. The actuation is based on DC motors, belt and pulley systems and harmonic drive reduction gears. The sensory equipment consists of joint encoders, force/torque sensors and inertial measurement systems. The control hardware is centered around a dSpace digital signal processor. A smooth walking trajectory is generated. A ground impact compensator, an early landing trajectory modification system, controllers for the foot and trunk orientation, and independent joint position controllers are implemented. Experimental walking results with the leg module are obtained too.

In this paper, a versatile and reconfigurable microassembly workstation designed and realized as a research tool for investigation of the problems in microassembly and micromanipulation processes and recent developments on mechanical and control structure of the system with respect to the previous workstation are presented. These developments include: (i) addition of a manipulator system to realize more complicated assembly and manipulation tasks, (ii) addition of extra DOF for the vision system and sample holder stages in order to make the system more versatile (iii) a new optical microscope as the vision system in order to visualize the microworld and determine the position and orientation of micro components to be assembled or manipulated, (iv) a modular control system hardware which allows handling more DOF. In addition several experiments using the workstation are presented in different modes of operation like tele-operated, semiautomated and fully automated by means of visual based schemes.

Abstract— Induction motor speed sensorless torque control, which allows operation at low and zero speed, optimizing both torque response and efficiency, is proposed. The control is quite different than the conventional field-oriented or direct torque control. A new discontinuous stator current FPGA based controller and rotor flux observer based on continuous sliding mode and Lyapunov theory are developed. A smooth transition into the field weakening region and the full utilization of the inverter current and voltage capability are possible. The reference tracking performance of torque and rotor flux is demonstrated in terms

In this paper, a sliding-mode-based design framework for fully actuated mechanical multibody system is discussed. The framework is based on the possibility to represent complex motion as a collection of tasks and to find effective mapping of the system coordinates that allows decoupling task and constraint control so one is able to enforce concurrently, or in certain time succession, the task and the constraints. The approach seems naturally encompassing the control of motion systems in interaction, and it allows application to bilateral control, multilateral control, etc. Such an approach leads to a more natural interpretation of the system tasks, simpler controller design, and easier establishment of the systems hierarchy. It allows a unified mathematical treatment of task control in the presence of constraints required to be satisfied by the system coordinates. In order to show the applicability of the proposed techniques, simulation and experimental results for high-precision systems in microsystem assembly tasks and bilateral control systems are presented.

Abstract—Design of a motion control system, convenient for a wide range of applications in industry, space, biology, medicine, particularly including more than one physics environment is very important. Well known control architectures like trajectory tracking, compliance control, interaction force control are scientific milestones which has common control task: to maintain desired system configuration. In this concept, motion control system can be an unconstrained motion-performed interaction with neither environment nor any other system, or constrained motion-system in contact with environment and/or other systems. This paper provides the function based design approach to formulate control of constrained system particularly bilateral systems in micromanipulation applications. The control objective aimed to maintain desired functional relations between human and environment defining convenient tasks and their proper relations on master and slave motion systems. The custom built micromanipulation setup presented here designed for the implementation of the methodology. Preliminary results concerning position tracking, force control and transparency between master and slave systems are clearly demonstrated.

Design of a motion control system should take into account (a) unconstrained motion performed without interaction with environment or any other system, and (b) constrained motion with system in contact with environment or other systems. 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. The same design approach can be used to formulate control in bilateral systems aimed to maintain desired functional relations between human and environment through master and slave motion systems. Implementation of the methodology is currently being pursued with a custom built tele-micromanipulation setup and preliminary results concerning force/position tracking and transparency between master and slave are clearly demonstrated.

The problem of estimating motion and structure from a sequence of images has been a major research theme in machine vision for many years and remains one of the most challenging ones. In this work, we use sliding mode observers to estimate the motion and the structure of a moving body with the aid of a change-coupled device (CCD) camera. We consider a variety of dynamical systems which arise in machine vision applications and develop a novel identification procedure for the estimation of both constant and time-varying parameters. The basic procedure introduced for parameter estimation is to recast image feature dynamics linearly in terms of unknown parameters and construct a sliding mode observer to produce asymptotically correct estimates of the observed image features, and then use the observer input to compute parameters. Much of our analysis has been substantiated by computer simulations and real experiments.