the natural frequency and pull-in instability of clamped-clamped nano-actuators in the presence of a dielectric layer are analyzed. the influence of the presence of casimir force, electrostatic force, fringing field effect, axial force, stretching effects and the size effect are taken into account. the governing equation of the dynamic response of the actuator is transformed in a non-dimensiona...

This article has studied the effect of ratio of stiffness and thickness between piezoelectric actuators and host plat has been explored on optimal pattern for placement of piezoelectric work pieces around a hole in thin isotropic plate under static loading to reduce stress concentration. The piezoelectric actuators reduce directly or indirectly the stress concentration by applying positive and ...

In this paper, three issues related to three-dimensional multilink rigid body systems are considered: dynamics, actuation, and inversion. Based on the Newton-Euler equations, a state space formulation of the dynamics is discussed that renders itself to inclusion of actuators, and allows systematic ways of stabilization and construction of inverse systems. The development here is relevant to rob...

In this paper, an incremental nonlinear dynamic inversion (INDI) control scheme is proposed for the attitude tracking of a helicopter with model uncertainties, and actuator delay saturation constraints. A finite integral compensation based on reduction used to compensate delay, can guarantee semi-globally uniformly ultimately bounded tracking. The overall controller separated into rate, attitud...

piezoelectric actuators are widely used in micro manipulation applications. however hysteresis nonlinearity limits accuracy of these actuators. this paper presents a novel approach utilizing a piezoelectric nano-stage as slave manipulator of a teleoperation system. the prandtl-ishlinskii (pi) model is used to model actuator hysteresis in feedforward scheme to cancel out this nonlinearity. a pas...

Planar, underactuated, biped walkers form an important domain of applications for hybrid dynamical systems. This paper presents the design of exponentially stable walking controllers for general planar bipedal systems that have one degree of freedom greater than the number of available actuators. The within-step control action creates an attracting invariant set—a two dimensional zero dynamics ...

The modeling of the time dependent, dynamic behavior of the human musculoskeletal system results in a large scale mechanical multibody system. This consists of submodels for the skeleton, wobbling masses, muscles and tendons as redundant actuators. Optimization models are required for the simulation of the muscle groups involved in a motion. In contrast to the inverse dynamics simulation the fo...

This paper deals with the dynamics and control of a two degree of freedom robot arm actuated by pneumatic artificial muscles (PAMs). The high power-weight ratio of PAMs justifies their use as actuators in robotics. To achieve trajectory tracking performance, controllers are constructed based on a dynamic model of the robot arm. Due to the high non-linear dynamics of the robotic system, fuzzy co...

In this paper a continuous periodic time-varying feedback law is proposed that exponentially stabilizes both the position and orientation of a surface vessel having only two actuators. To this end, a stability result for a class of homogeneous time-periodic systems is presented. The exponential stability provided by the proposed feedback law does not depend on exact knowledge of the model param...

Short Description: We have investigated the deep and important question of how the physical or body dynamics and the control or neural dynamics can be coupled in optimal ways. By simulating development in a robot, we examined if developmental progressions in the robot’s sensory-motor and neural systems can speed up the learning process. This might be indeed the case as shown by the results pres...