A closed-loop detection and open-loop control strategy for booms of truck-mounted concrete pump

2013 ◽  
Vol 31 ◽  
pp. 265-273 ◽  
Author(s):  
Xiaojie Sun ◽  
Hua Ye ◽  
Shumin Fei
Keyword(s):  
Control Strategy ◽  
Closed Loop ◽  
Open Loop ◽  
Open Loop Control ◽  
Loop Control ◽  
Loop Detection ◽  
Concrete Pump

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.

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.

Control of a Digital Micromirror Device Using Input Shaping

2007 ◽  
Author(s):  
H. Jammoussi ◽  
S. Choura ◽  
E. M. Abdel-Rahman ◽  
H. Arafat ◽  
A. Nayfeh ◽  
...  
Keyword(s):  
Electrostatic Field ◽  
Control Strategy ◽  
Nonlinear Function ◽  
Input Voltage ◽  
Open Loop ◽  
Input Shaping ◽  
Control Law ◽  
Digital Micromirror Device ◽  
Open Loop Control ◽  
Loop Control

In this paper, an open-loop control strategy is proposed for maneuvering the angular motion of a Digital Micromirror Device (DMD). The control law is based on a micromirror model that accounts for both bending and torsion motions. The model characterizes two DMD configurations: with and without contact with the substrate. The device is actuated using an electrostatic field which is a nonlinear function of the states and input voltage. The proposed control strategy is a Zero Vibration (ZV) shaper. It overshoots the DMD to its desired final angle by appropriately varying two independent input voltages. Actuating voltages and switching times are determined to maneuver the DMD from −10° to +10° tilt angles while reducing the residual vibrations.

scholarly journals Sliding Mode Control with Dynamical Correction for Time-Delay Piezoelectric Actuator Systems

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 132 ◽  
Author(s):  
Javier Velasco ◽  
Oscar Barambones ◽  
Isidro Calvo ◽  
Joseba Zubia ◽  
Idurre Saez de Ocariz ◽  
...  
Keyword(s):  
Time Delay ◽  
Sliding Mode Control ◽  
Control Strategy ◽  
Sliding Mode ◽  
Open Loop ◽  
Open Loop Control ◽  
Loop Control ◽  
Mode Control ◽  
Control Response ◽  
Dynamical Correction

In piezoelectric actuators (PEAs), which suffer from inherent nonlinearities, sliding mode control (SMC) has proven to be a successful control strategy. Nonetheless, in micropositioning systems with time delay, integral proportional control (PI), and SMC, feedback control schemes have a tendency to overcompensate and, consequently, high controller gains must be rejected. This may produce a slow and inaccurate response. This paper presents a novel control strategy that deals with time-delay micropositioning systems aimed at achieving precise positioning by combining an open-loop control with a modified SMC scheme. The proposed SMC with dynamical correction (SMC-WDC) uses the dynamical system model to adapt the SMC inputs and avoid undesirable control response caused by delays. In order to develop the SMC-WDC scheme, an exhaustive analysis on the micropositioning system was first performed. Then, a mixed control strategy, combining inverse open-loop control and SMC-WDC, was developed. The performance of the presented control scheme was analyzed and compared experimentally with other control strategies (i.e., PI and SMC with saturation and hyperbolic functions) using different reference signals. It was found that the SMC-WDC strategy presents the best performance, that is, the fastest response and highest accuracy, especially against sudden changes of reference setpoints (frequencies >10 Hz). Additionally, if the setpoint reference frequencies are higher than 10 Hz, high integral gains are counterproductive (since the control response increases the delay), although if frequencies are below 1 Hz the integral control delay does not affect the system’s accuracy. The SMC-WDC proved to be an effective strategy for micropositioning systems, dealing with time delay and other uncertainties to achieve the setpoint command fast and precisely without chattering.

Synthesis of Robust Gain Matrices for Adaptive Rotor Vibration Control

1997 ◽  
Vol 119 (2) ◽  
pp. 298-300 ◽  
Author(s):  
C. R. Knospe ◽  
S. M. Tamer ◽  
S. J. Fedigan
Keyword(s):  
Steady State ◽  
Control Strategy ◽  
Synthesis Method ◽  
Open Loop ◽  
Active Magnetic Bearings ◽  
Open Loop Control ◽  
Rotor Vibration ◽  
Loop Control ◽  
Structured Uncertainty ◽  
Steady State Performance

Experimental results have recently demonstrated that an adaptive open-loop control strategy can be highly effective in the suppression of the unbalance induced vibration of rotors supported in active magnetic bearings. A synthesis method is presented for determining the adaptive law’s gain matrix such that the adaptation’s stability and steady-state performance are robust with respect to structured uncertainty.

LIM Control Strategy Supported by Genetic Algorithm with Unbalanced AC Source

2018 ◽  
Vol 19 (4) ◽  
Author(s):  
Matheus Garcia Soares ◽  
Afonso Bernardino Almeida Junior ◽  
Thiago Berger Canuto Alves ◽  
Luciano Martins Neto
Keyword(s):  
Computational Model ◽  
Control Strategy ◽  
Induction Motors ◽  
Linear Motor ◽  
Open Loop ◽  
Open Loop Control ◽  
Loop Control ◽  
Linear Motors ◽  
Low Speeds ◽  
Supply Voltages

AbstractThis work presents the improvement of an open loop control strategy for linear induction motors operating at low speeds. The improvement is provided through the application of genetic algorithms in determining unbalance factors of the supply voltages of the linear motor. For this, a computational model of the linear motor was used as the evaluation function. The computational model was developed based on the equations of the linearized induction motor. The proposed methodology is validated through the comparison between computational results and experimental data performed in a linear motor prototype. This methodology allows to evaluate the influence of the unbalance of the supply voltages for linear motors working at low speeds.

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.

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