Transfemoral Prosthesis with Polycentric Knee Mechanism: Design, Kinematics, Dynamics and Control Strategy

2013 ◽  
Author(s):  
Poliakov
Keyword(s):  
Mechanism Design ◽  
Control Strategy ◽  
Dynamics And Control ◽  
Transfemoral Prosthesis ◽  
And Control

Dynamics and Control of Electroporation

2008 ◽  
Author(s):  
Susan Basile ◽  
Xiaopeng Zhao ◽  
Mingjun Zhang
Keyword(s):  
Drug Delivery ◽  
Bifurcation Analysis ◽  
Control Strategy ◽  
Control Algorithm ◽  
Pore Radius ◽  
Dynamical Analysis ◽  
Dimensional Model ◽  
Electric Pulses ◽  
Dynamics And Control ◽  
And Control

Electroporation has become an important tool for drug delivery such as gene therapy. The technique uses electric pulses to create transient pores in the cell membrane. To ensure proper uptake of targeted molecules, it is essential to create sufficiently large pores, which remain open long enough. In this work, we explore evolution of the pores using dynamical analysis and control of electroporation based on a simplified two-dimensional model. A detailed bifurcation analysis reveals the existence of saddle-node bifurcations, which induce hysteresis into the system dynamics. The bifurcation analysis also sheds light on the relation between the applied voltage and the pore radius. Based on the dynamics and bifurcation analysis, we design a feedback control algorithm that is able to achieve any desired pore size. Numerical examples demonstrate the control strategy is robust. The control algorithm will improve the operation of electroporation in drug delivery.

Attitude Dynamics and Control of Liquid Filled Spacecraft with Large Amplitude Fuel Slosh

2016 ◽  
Vol 33 (1) ◽  
pp. 125-136 ◽  
Author(s):  
M.-L. Deng ◽  
B.-Z. Yue
Keyword(s):  
Control Strategy ◽  
Attitude Control ◽  
Large Amplitude ◽  
Lyapunov Theory ◽  
Attitude Dynamics ◽  
Equivalent Mechanical Model ◽  
Attitude Maneuver ◽  
Dynamics And Control ◽  
Fuel Slosh ◽  
And Control

AbstractThis paper focuses on the attitude dynamics and control of liquid filled spacecraft, and the large amplitude fuel slosh dynamics is included by using an improved moving pulsating ball model. The moving pulsating ball model is an equivalent mechanical model that is capable of imitating the whole liquid reorientation process, specifically for the occurrence of large amplitude slosh. This model is improved by incorporating a static capillary force and an effective mass factor. The improvements on this model are validated with previously published experiment results. The spacecraft attitude maneuver is implemented by the momentum transfer technique, and the feedback control strategy is designed based on Lyapunov theory. The effects of liquid viscosity, tank location and desired steady time on sloshing torque and control torque are investigated. The attitude control strategy applied in this paper is proved to be applicable for the coupled liquid filled spacecraft system. The obtained conclusions are useful to aid in liquid filled spacecraft overall design.

Vorticity dynamics and control of the turning locomotion of 3D bionic fish

2018 ◽  
Vol 232 (14) ◽  
pp. 2524-2535 ◽  
Author(s):  
Zhiqiang Xin ◽  
Chuijie Wu
Keyword(s):  
Control Strategy ◽  
The Body ◽  
Immersed Boundary ◽  
Directional Control ◽  
Depth Analysis ◽  
Dynamics And Control ◽  
Turning Motion ◽  
Volume Method ◽  
And Control ◽  
3D Bionic Fish

Numerical simulations of the turning manoeuvre of a 3D bionic fish in a viscous flow are conducted in the present study using a 3D computational fluid dynamics package, which includes the adaptive multi-grid finite volume method, the immersed boundary method, the volume of fluid method, and the control strategy of fish swimming. The 3D bionic fish can turn quickly primarily using the directional control strategy of the swing of the head, in which the impacts of the swing of the fish body and the caudal fin on the directional control are also taken into account. This result demonstrates that the directional control strategy of the swing of the head is effective. An in-depth analysis of the fluid mechanism of the swimming manoeuvre of the 3D bionic fish reveals that the rotation moment in favour of turning motion is obtained by the pressure around the body of the fish, which is induced by the wake vortex, and the swing of the fish can manipulate the location and the strength of vortices shed from the fish body.

Attitude maneuver control of liquid-filled spacecraft with unknown inertia and disturbances

2019 ◽  
Vol 25 (8) ◽  
pp. 1460-1469 ◽  
Author(s):  
Xiao Juan Song ◽  
Shu Feng Lu
Keyword(s):  
Control Strategy ◽  
Sliding Mode ◽  
Adaptive Sliding Mode Control ◽  
Underactuated System ◽  
Mass Model ◽  
Attitude Maneuver ◽  
Dynamics And Control ◽  
Conservation Of Momentum ◽  
And Control ◽  
The Mathematical Model

The attitude maneuver dynamics and control strategy for a fuel-filled spacecraft with uncertain inertia and external disturbances are studied. The mathematical model of a three-axis stabilized spacecraft is established based on the law of conservation of momentum, and the liquid fuel inside the partially-filled fuel tank is represented by an equivalent two-mode spring-mass model. The adaptive sliding mode control law is designed for this kind of underactuated system, and the Lyapunov stability analysis guarantees that all system trajectories reach and remain on the sliding surface. Then, the multiple mode input shapers are used to suppress the sloshing of the fluid fuel. The numerical results show good performance and effectiveness of the control strategy.

scholarly journals Preliminary analysis of the PreFlexMS molten salt once-through steam generator dynamics and control strategy

2017 ◽  
Author(s):  
Stefano Trabucchi ◽  
Francesco Casella ◽  
Tommaso Maioli ◽  
Cristina Elsido ◽  
Davide Franzini ◽  
...  
Keyword(s):  
Molten Salt ◽  
Steam Generator ◽  
Control Strategy ◽  
Preliminary Analysis ◽  
Dynamics And Control ◽  
And Control
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