Microassembly via Coordinated Manipulation of Objects Using a Multifingered Micromanipulator

2011 ◽  
Author(s):  
Christopher Pelzmann ◽  
Laxman Saggere
Keyword(s):  
Closed Loop ◽  
State Of The Art ◽  
Control Strategies ◽  
Open Loop ◽  
Open Loop Control ◽  
Multiple Objects ◽  
Loop Control ◽  
Micro Scale ◽  
Novel Approach ◽  
On Chip

This paper presents a novel approach to manipulation and assembly of micro-scale objects using a chip-scale multi-fingered micromanipulator, in which multiple, independently controlled compliant fingers coordinate with each other to grasp and manipulate multiple objects simultaneously on-chip. The structural and functional advantages of this multi-fingered micromanipulator in achieving high dexterity in a compact form as compared to other state-of-the-art manipulation tools are discussed. A formulation of the kinematics of the manipulator’s compliant fingers along with two different control strategies including an operator-driven closed-loop control and a semi-autonomous open-loop control for coordinated manipulation and on-chip assembly of micro-scale objects are introduced. Finally, the details of implementation of both control strategies and successful experimental demonstration of manipulations and assembly of two interlocking micro-scale parts with sub-micron mating clearance using the multifingered manipulator are presented.

Modeling of a Hydraulic Elevator Driven by an Open-Loop Control

2009 ◽  
Author(s):  
Roberto Strada ◽  
Alberto Oldani
Keyword(s):  
Power Generation ◽  
Closed Loop ◽  
Open Loop ◽  
The Other ◽  
Open Loop Control ◽  
Proportional Valve ◽  
Loop Control ◽  
Complete Knowledge ◽  
Motion Time ◽  
Loop Control System

Electro-hydraulic elevators are widely used systems, especially in low level buildings, due to their very good ratio between power generation and dynamic response. Generally, the goal of an elevator system is just to reach the floor with a precision enough to be comfortable for the passengers, without the need to follow a specific law of motion; hence an open-loop control system could be enough. Otherwise such a kind of solution reduces the number of components, bringing down the costs of production. On the other hand a complete knowledge of the mechanical system’s behaviour is required. In this work we deal with the analysis of the behaviour of a commercial hydraulic elevator driven by an open loop control that monitors the downstream pressure of the proportional valve supplying the cylinder. At the end of the paper, a closed loop solution based on the pressure measurement and on the motion time is proposed.

scholarly journals Control of Flexible Manipulator Systems

1996 ◽  
Vol 210 (2) ◽  
pp. 113-130 ◽  
Author(s):  
M O Tokhi ◽  
A K M Azad
Keyword(s):  
Closed Loop ◽  
Control Strategies ◽  
Open Loop ◽  
Flexible Manipulator ◽  
Closed Loop Control ◽  
Loop Control ◽  
Acceleration Feedback ◽  
Low Pass ◽  
Input Torque ◽  
Collocated Control

This paper presents an investigation into the development of open-loop and closed-loop control strategies for flexible manipulator systems. Shaped torque inputs, including Gaussian-shaped and low-pass (Butter-worth and elliptic) filtered input torque functions, are developed and used in an open-loop configuration and their performance studied in comparison to a bang-bang input torque through experimentation on a single-link flexible manipulator system. Closed-loop control strategies that use both collocated (hub angle and hub velocity) and non-collocated (end-point acceleration) feedback are then proposed. A collocated proportional and derivative (PD) control is first developed and its performance studied through experimentation. The collocated control is then extended to incorporate, additionally, non-collocated feedback through a proportional integral derivative (PID) configuration. The performance of the hybrid collocated and non-collocated control strategy thus developed is studied through experimentation. Experimental results verifying the performance of the developed control strategies are presented and discussed.

Optimal Performance of Cylinder-by-Cylinder and Fuel Bank Controllers for a CIDI Engine

2009 ◽  
Author(s):  
Ming Fang ◽  
Shawn Midlam-Mohler ◽  
Rajaram Maringanti ◽  
Fabio Chiara ◽  
Marcello Canova
Keyword(s):  
Closed Loop ◽  
Open Loop ◽  
Optimal Performance ◽  
Combustion Control ◽  
Open Loop Control ◽  
Loop Control ◽  
Engine Model ◽  
Engine Combustion ◽  
Performance Gains ◽  
Near Future

At present, Diesel engine combustion in most production engines is controlled via open-loop control. Increasing pressure from tightening emissions standards and on-board diagnosis requirements has made closed-loop combustion a possibility for production engines in the near future. For new combustion concepts, such as Homogeneous Charge Compression Ignition and other low NOx regimes, the need for closed-loop combustion control is very strong. In this work, the applicability of closed-loop combustion control for controlling the variability between cylinders in conventional Diesel combustion is explored through the use of a high-fidelity engine model. The problem is formulated such that the optimal performance of two different closed-loop control concepts can be evaluated through optimization rather than via control design. It is found that, for the types of disturbances occurring in a non-faulty engine, that control of individual cylinders leads to small performance gains compared to fuel bank control.

A Method for Teaching Feedback Control Using the Enhanced Mass-Spring-Damper System

2011 ◽  
Author(s):  
Dean H. Kim
Keyword(s):  
Feedback Control ◽  
Control Strategies ◽  
Open Loop ◽  
Open Loop Control ◽  
Improve Performance ◽  
Loop Control ◽  
System Input ◽  
Advanced Controls ◽  
Mass Spring ◽  
Force Generator

This paper presents a method that the author has developed to teach students about the need for feedback control and to facilitate the understanding of controller implementation. The initial discussion focuses on the limitations of open-loop control to improve performance of the traditional mass-spring-damper system. The key contribution is the introduction of an enhanced mass-spring-damper system with a position sensor and force generator, resulting in voltages as system input and output. This enhanced system provides a foundation for discussion of basic feedback control strategies such as PID-Control in addition to advanced controls concepts. The analysis is provided in time-domain to facilitate the understanding of these important controls concepts.

scholarly journals Turbulent boundary layer under the control of different schemes

2017 ◽  
Vol 473 (2202) ◽  
pp. 20170038 ◽  
Author(s):  
Z. X. Qiao ◽  
Y. Zhou ◽  
Z. Wu
Keyword(s):  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
High Speed ◽  
Control Strategies ◽  
Local Maximum ◽  
Open Loop ◽  
Open Loop Control ◽  
Feed Forward ◽  
Loop Control ◽  
Combined Feed

This work explores experimentally the control of a turbulent boundary layer over a flat plate based on wall perturbation generated by piezo-ceramic actuators. Different schemes are investigated, including the feed-forward, the feedback, and the combined feed-forward and feedback strategies, with a view to suppressing the near-wall high-speed events and hence reducing skin friction drag. While the strategies may achieve a local maximum drag reduction slightly less than their counterpart of the open-loop control, the corresponding duty cycles are substantially reduced when compared with that of the open-loop control. The results suggest a good potential to cut down the input energy under these control strategies. The fluctuating velocity, spectra, Taylor microscale and mean energy dissipation are measured across the boundary layer with and without control and, based on the measurements, the flow mechanism behind the control is proposed.

scholarly journals Model-based Control Strategies for Anaerobic Digestion Processes

BIOMATH ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 1907127 ◽  
Author(s):  
Neli Dimitrova ◽  
Mikhail Krastanov
Keyword(s):  
Wastewater Treatment ◽  
Anaerobic Digestion ◽  
Methane Production ◽  
Control Strategies ◽  
A Priori ◽  
Open Loop ◽  
Open Loop Control ◽  
Loop Control ◽  
Model Based Control ◽  
Anaerobic Wastewater Treatment

In this paper we consider a four-dimensional bioreactor model, describing an anaerobic wastewater treatment with methane production. Different control strategies for stabilizing the dynamics are presented and discussed. A general and practice-oriented bounded open-loop control is proposed, aimed to steer the model solutions towards an a priori given set in thephase plane.

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