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Precision positioning machines are required to run with higher speed and higher accuracy. The high running speed can cause strong excitations on the machine structure, which results in severe structure vibration and long settling time. This paper presents a low-vibration motion profile generation method to reduce the residual vibration. The acceleration profile is designed by using a level-shifted...
Two wheel mobile manipulator has the potential of becoming a multi-skilled robot in the field of robotics and it is already implemented by using inverted pendulum control. Centre of gravity position (COG) is controlled to achieve the balancing of robot. Since vibration of manipulator arms affect to the COG positions of the inverted pendulum, balancing of the robot deteriorates. Therefore, vibration...
We consider a problem of stabilization of the Euler-Bernoulli beam. The beam is controlled at one end (using position and moment actuators) and has the ??sliding?? boundary condition at the opposite end. We design the controllers that achieve any prescribed decay rate of the closed loop system, improving upon the existing ??boundary damper?? controllers. The idea of the control design is to use the...
For operation of robot arm when its end-effector contacts the arm's environment, force and motion control is necessary. Force and motion control for cylindrical curved surface wall using a three-link arm having spring end-effector was carried out by experiments and simulations. Low stiffness of the end-effector's spring by converting the force into compression displacement can absorb unknown high...
This paper presents a nano positioning mechanism with flexure hinge and damper. The nano stage represented in this paper consists of a leaf spring guides and the voice coil motor (VCM) since it provides long working range and the control is easy. However, when the leaf spring is used alone, mechanism has very small damping, which reduces the system stability and causes mechanical vibration in positioning...
This paper is about a mechanical system with a mechanical system coupled with two passive vibration absorbers, one mass-spring type and one cantilever beam type. The overall system is made active with the addition of an external control force, then the Position Feedback control to improve its robustness properties with respect to frequency variations or simultaneous resonant frequencies.
This paper presents a new control method for high precision positioning of a dual solenoid actuator system which contains circuital nonlinearities as well as Coulomb friction. A balance control strategy is first applied to control the position actuator consisting of two unipolar solenoids. Variable Model Reference Zero Vibration Balance (VMRZVB) control which combines the advantages of balance control,...
Three components of a concept robotic fueling system for automatic refueling of vehicles for commercial use were designed and tested. The components of interest were the control system (user interface and logic), vehicle positioning system (sensor system), and the automatic controlled dispensing of fuel (fuel nozzle). Tests on a scaled bench-top vehicle model achieved detection and orientation of...
This paper proposes a novel planar electromagnetic-actuated positioning stage. The stage is suspended by the monolithic parallel flexure mechanism, which motion comes from the deformation of the flexure. A linear electromagnetic actuator which consists of a near-uniform magnetic field and four coils is designed and implementation to provide the propelling force for 3-DOF motions. In order to suppress...
In this paper, active control of space manipulator with flexible-link and flexible-joint was investigated based on the singular perturbation method. Owing to the combined effects of the link and joint flexibilities, the dynamics model of this type of manipulator became more complex and led to a series of unsolved control system. To simplify the design of control system, singular perturbation method...
In this study, hierarchical adaptive network based fuzzy logic controller for a single flexible link robot manipulator is designed. This study is aimed to get the end of the flexible robot manipulator to desired position and terminate vibrations on arm while it moves under the action of an external driving torque. The proposed controller has two subsystems. The fast-subsystem reduces the vibration...
The main object in this study concerns to vibration control of a one-link flexible arm system. The robot link manipulators are widely used in various industrial applications. A variable structure system (VSS) non-linear observer has been proposed in order to reduce the oscillation in controlling the angular. The non-linear observer parameters are optimized using a novel version of simultaneous perturbation...
New gains tuning and impedance control method were addressed for flexible base moving manipulators. Slow and fast dynamics of robot are decoupled using singular perturbation method. Then, using sliding mode control method, an impedance control law was derived for the slow dynamics. Combined control law was proposed comprising the impedance control law and a feedback control law for the fast dynamics...
This paper leads with the active cancellation problem of mechanical vibrations in rotor-bearing systems. The use of an active disk is proposed for actively balancing a rotor by means of locating a balancing mass at a suitable position. Two nonlinear controllers with integral compensation are proposed to put the balancing mass at a specific position. Algebraic identification is used for on-line eccentricity...
Elastic elements, such as timing belts, have become more attractive where long travel length is required. However, the compliance of the belt causes mechanical resonance which reduces stability margins, forces servo gains down and deteriorates machine performance. In order to suppress the vibration of a linear belt-driven system and improve the transient response performance, the mathematical model...
This work considers the design of point-to-point input trajectories for flexible motion systems. The objective is to excite the system's dynamics as little as possible so as to reduce residual vibration and settling time. Simulation and experimental results of a recently developed optimization framework for polynomial splines are presented. This framework is capable of automatically selecting the...
A novel method is proposed for controlling the position of a vibrating proof mass in a z-axis MEMS gyroscope while simultaneously approximating its rotation rate in a third dimension independent of cross coupling terms. Designing the controller to require minimal model information and reject a broad range of disturbances, including the cross coupling terms, dramatically reduces controller complexity...
The paper presents a novel oscillation controller for controlling the driving mode (or drive axis) of a vibrational gyroscope to oscillate at a desired trajectory. The controller consists of a PD controller and an online extended state observer (ESO). The ESO is used to estimate the system states and the discrepancy between the real system and the mathematical model of the gyroscope. The PD controller...
This paper presents the use of angular position control approaches for a flexible robot manipulator with disturbances effect in the dynamic system. Delayed Feedback Signal (DFS) and Proportional-Derivative (PD) controller are the techniques proposed in this investigation to actively control the vibrations of flexible structure. A constrained planar single-link flexible manipulator is considered and...
An enhancement of the dynamic behavior of the rotating shaft work at high operating speed by using Squeeze film dampers (SFDs) has been becoming an important part in changing the dynamic characteristics of machinery. In this paper, a new type Controllable Squeeze Film Damper (CSFD) is proposed, designed and fabricated by changing the clearance of the thin-film fluid. Both of the critical speed and...
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