The main function of haptic teleoperation is to provide the user with force feedback from a remote environment. Use of a passive haptic master complicates the replication of remote forces due to the limitations of passive actuators. An active master can drive its endpoint anywhere in the workspace and produce forces limited by the output of the motors. In a passive system the position of the ma...

This paper considers the stabilization problem of the Acrobot, a widely studied benchmark nonlinear under-actuated mechanical system. For such systems the design of control Law becomes a challenging task owing to complex internal dynamics and lack of feedback linearizibility. These result in need of closed form solutions for highly nonlinear equations or hybrid/switching controllers. A novel no...

The paper deals with a novel control algorithm for simultaneous stabilization and trajectory tracking of underactuated nonlinear mechanical systems (UNMS) with included actuators dynamics. Simultaneous stabilization and trajectory tracking refer to arbitrary chosen actuated and unactuated degrees of freedom (DOF) of the system. The proposed control approach can be applied both to the second-ord...

Many studies have been conducted for quantitative/qualitative analysis and comparison of various teleoperation schemes. Position-position, force-position and 4-channels are to name a few. However most of this research has been focused on electrically actuated manipulators. This paper documents the comparative study of various teleoperation schemes explicitly for hydraulic manipulators. Identica...

Measuring the state variables of systems actuated by shape memory alloys (SMAs) is normally a difficult task because of the small diameter of the SMA wires. In such cases, as an alternative, observers are used to estimate the state vector. This paper presents an extended Kalman filter (EKF) for estimation of the state variables of a single-degree-of-freedom rotary manipulator actuated by an SMA...

This paper deals with the L2 stability of a shape memory alloy actuated position control system, based on a single wire under constant axial load. Presuming a controller has certain speci c dissipativity characteristics, it is shown that system stability can be guaranteed for a large class of controllers. In particular, the results can be used to show stability under approximated PID, PI and PD...

This study presents the estimation of a nonlinear autoregressive moving average with exogenous inputs (NARMAX) model of a novel hydraulically actuated electronic unit injection (HEUI) system. The injection pressure-fuel rate relationship is detected to understand the HEUI system and its effects on engine performance. The dynamics of causation is first investigated in the time domain to estimate...

This work presents a novel motion planning framework, rooted in nonlinear programming theory, that treats uncertain fully and underactuated dynamical systems described by ordinary differential equations. Uncertainty in multibody dynamical systems comes from various sources, such as system parameters, initial conditions, sensor and actuator noise, and external forcing. Treatment of uncertainty i...

The control of 4-DOF underactuated overhead crane system poses a challenging control problem as it has extra degree of freedom (DOF) compared to its popular 3DOF variant. The extra DOF represents strong state coupling and hence more complicated system dynamics. We propose Geometric Passivity Based Control (PBC) methodology for synthesis of nonlinear stabilising feedback control law. The structu...

In dip-pen nanolithography ~DPN!, nanoscale chemical patterns are created by directly transferring chemical molecules from the tip of an atomic force microscope probe to a surface. We report the development of a thermally actuated probe array for DPN applications. The array consists of ten thermal bimorph actuated probes, each 300 mm long, with a lateral spacing of 100 mm. The probes are actuat...