scholarly journals Wetting-Induced Polyelectrolyte Pore Bridging

Membranes ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 671
Author(s):  
Anna Kalde ◽  
Johannes Kamp ◽  
Elizaveta Evdochenko ◽  
John Linkhorst ◽  
Matthias Wessling
Keyword(s):  
Formation Control ◽  
Position Control ◽  
Phase Boundaries ◽  
Precise Position ◽  
Ion Separation ◽  
Separation Membranes ◽  
Active Layers ◽  
Polyelectrolyte Complexation ◽  
Manufacturing Procedure ◽  
Diffusion Dialysis

Active layers of ion separation membranes often consist of charged layers that retain ions based on electrostatic repulsion. Conventional fabrication of these layers, such as polyelectrolyte deposition, can in some cases lead to excess coating to prevent defects in the active layer. This excess deposition increases the overall membrane transport resistance. The study at hand presents a manufacturing procedure for controlled polyelectrolyte complexation in and on porous supports by support wetting control. Pre-wetting of the microfiltration membrane support, or even supports with larger pore sizes, leads to ternary phase boundaries of the support, the coating solution, and the pre-wetting agent. At these phase boundaries, polyelectrolytes can be complexated to form partially freestanding selective structures bridging the pores. This polyelectrolyte complex formation control allows the production of membranes with evenly distributed polyelectrolyte layers, providing (1) fewer coating steps needed for defect-free active layers, (2) larger support diameters that can be bridged, and (3) a precise position control of the formed polyelectrolyte multilayers. We further analyze the formed structures regarding their position, composition, and diffusion dialysis performance.

Precise Position Control of Piezo Actuator

2018 ◽  
pp. 32-1-32-12
Author(s):  
Jian-Xin Xu ◽  
Sanjib Kumar Panda
Keyword(s):  
Position Control ◽  
Piezo Actuator ◽  
Precise Position

Modeling and Precise Position Control of Flexible Joints with Harmonic Drives

2021 ◽  
Author(s):  
Yiwei Tang ◽  
Xin Sun ◽  
Qi He ◽  
Xi Xiao ◽  
Weihua Wang
Keyword(s):  
Position Control ◽  
Flexible Joints ◽  
Precise Position

scholarly journals Precise Position Control of a Stepping Motor in Micro-step Drive Using Pre-compensator

2018 ◽  
Vol 7 (4) ◽  
pp. 369-370 ◽  
Author(s):  
Kenshi Matsuo ◽  
Takeshi Miura ◽  
Katsubumi Tajima
Keyword(s):  
Position Control ◽  
Stepping Motor ◽  
Precise Position ◽  
Step Drive

Aerial Contact Manipulation With Soft End-Effector Compliance and Inverse Kinematic Compensation

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Xinjun Sheng ◽  
Zhao Ma ◽  
Ningbin Zhang ◽  
Wei Dong
Keyword(s):  
Degrees Of Freedom ◽  
Position Control ◽  
Mechanical Design ◽  
Impact Resistance ◽  
High Strength ◽  
Inverse Kinematic ◽  
End Effector ◽  
Precise Position ◽  
Positioning Errors ◽  
Aerial Platform

Abstract This paper presents the development of a six degrees-of-freedom manipulator with soft end-effector and an inverse kinematic compensator for aerial contact manipulation. Realizing the fact that aerial manipulators can hardly achieve precise position control, a compliant manipulator with soft end-effector is first developed to moderate end-effector positioning errors. The manipulator is designed to be rigid-soft combined. The rigid robotic arm employs the lightweight but high-strength materials. The compliance requirement is achieved by the soft end-effector so that the mechanical design for the joints are largely simplified. These two features are beneficial to lighten the arm and to ensure the accuracy. In the meantime, the pneumatic soft end-effector can further moderate the probable insufficient accuracy by endowing the manipulator with compliance for impact resistance and robustness to positioning errors. With the well-designed manipulator, an inverse kinematic compensator is then proposed to eliminate lumped disturbances from the aerial platform. The compensator can ensure the stabilization of the end-effector by using state estimation from the aerial platform, which is robust and portable as the movement of the platform can be reliably obtained. Both the accuracy and compliance have been well demonstrated after being integrated into a hexarotor platform, and a representative scenario aerial task repairing the wind turbine blade-coating was completed successfully, showing the potential to accomplish complex aerial manipulation tasks.

LOOKING FORWARD TO THE INTELLIGENT ELECTRICAL MACHINE: ELECTRONICS AND MACHINES COMBINE THEIR ABILITIES

1995 ◽  
Vol 05 (01) ◽  
pp. 45-63
Author(s):  
DIETRICH NAUNIN
Keyword(s):  
State Feedback ◽  
Position Control ◽  
Controller Design ◽  
Supply Voltage ◽  
Induction Machine ◽  
State Feedback Control ◽  
Electrical Machine ◽  
Precise Position ◽  
Electric Cars ◽  
Drive Systems

Electrical machines, more than 150 years old, have long been distinguished according to their mechanical structure and frequencies of their supply voltage (or current). This is not true any more after the electronic revolution. Since the fast development in power electronics as well as in control electronics these electronics can give any motor any desired speed-torque characteristic and any motor can become a servodrive having a very precise position control. By implementing digital control algorithms, mainly the cascaded, the state feedback or the cascaded state feedback control, and — if necessary, in addition — adaptive control procedures which compensate the variation of system parameters in the controller, the "intelligent electrical machine" — either with the synchronous or with the induction machine — is created. It is part of mechatronics. It can be installed in modern automated systems, in robots and tool machines, in all kinds of industrial drive systems as well as in locomotives and electric cars. Also modern methods like fuzzy logic and neural networks can be used. It seems that they will not create a second revolution in the control itself, but in the application areas of drives. They add some interesting features to the intelligent electrical machine and make it even more intelligent. They could also speed up the controller design in future.

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