Computer Simulation of a Variable Fill Hydraulic Dynamometer: Part 2: Steady State and Dynamic Open-Loop Performance

1992 ◽  
Vol 206 (1) ◽  
pp. 49-56 ◽  
Author(s):  
P G Hodgson ◽  
J K Raine
Keyword(s):  
Steady State ◽  
Closed Loop ◽  
Open Loop ◽  
Stable Set ◽  
Open Loop Control ◽  
Test Bed ◽  
Loop Control ◽  
Transient Phenomena ◽  
Absorption Performance ◽  
Dissipation Processes

Part 1 of this paper presented a theoretical model for the torque absorption and energy dissipation processes in a variable fill Froude-type hydraulic dynamometer. Effects of working compartment geometry changes on steady state running full torque absorption performance were also shown. Part 2 presents both steady state and dynamic computer simulations of an engine-dynamometer system under open-loop control. Comparisons between model simulations and test bed data show that the dynamic model reproduces both the negative torque-speed dynamometer characteristics and other transient phenomena that occur under real open-loop partial fill conditions. Requirements of control systems to modify this behaviour and ensure stable set point holding are introduced. Part 3 of the paper will deal with the simulation of the engine-dynamometer system under closed-loop control.

Computer Simulation of a Variable Fill Hydraulic Dynamometer; Part 1: Torque Absorption Theory and the Influence of Working Compartment Geometry on Performance

1991 ◽  
Vol 205 (3) ◽  
pp. 155-163 ◽  
Author(s):  
J K Raine ◽  
P G Hodgson
Keyword(s):  
Steady State ◽  
Open Loop ◽  
Working Fluid ◽  
Test Bed ◽  
Loop Control ◽  
Fluid Properties ◽  
Absorption Performance ◽  
Water Outflow ◽  
Vane Angle ◽  
Absorption Theory

A mathematical model of the steady state torque absorption process in variable fill hydraulic dynamometers is described. This is the initial part of a general model that has been developed to simulate the dynamic behaviour of Froude-type dynamometers under open-loop control and of an engine/dynamometer system under various closed-loop control modes. In this paper, the equations for steady state torque, energy dissipation, fluid vortex pressure in the working compartment and water outflow from the dynamometer are presented. Predictions by the model for the special case of characteristic running full torque absorption performance are compared with experimental test bed results for different working compartment geometries. Effects of vane angle and working fluid properties on maximum torque capability are examined. Subsequent parts of this paper will address the dynamic variable fill simulation.

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.

Experimental Study of Landing Gear Simulation Test-Bed

2014 ◽  
Vol 1030-1032 ◽  
pp. 1181-1184
Author(s):  
Miao Shang ◽  
Guo Min Lin ◽  
Wen Guang Zhang ◽  
Fei Zhou
Keyword(s):  
Control System ◽  
Closed Loop ◽  
Test System ◽  
Open Loop ◽  
Landing Gear ◽  
Test Bed ◽  
Simulation Test ◽  
Loop Control ◽  
System Experiment ◽  
Loop Control System

The basic composition of the landing gear simulator test-bed is discussed; The open loop control system experiment, closed-loop light control system experiment, the closed loop load control system are completed for the test system; The reliability and stability of test-bed system are validated by the experiment; The technical indexes of the landing gear simulation test-bed and the design requirement of electric control system are validated.

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.

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.

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.

A sketch drawing humanoid robot using image-based visual servoing

2019 ◽  
Vol 34 ◽  
Author(s):  
Meng-Cheng Lau ◽  
John Anderson ◽  
Jacky Baltes
Keyword(s):  
Error Correction ◽  
Visual Servoing ◽  
Humanoid Robot ◽  
Closed Loop ◽  
Open Loop ◽  
Experimental Results ◽  
Drawing Process ◽  
Open Loop Control ◽  
Loop Control ◽  
Error Correction Capability

Abstract This paper presents our sketch drawing artist humanoid robot research. One of the limitations of the existing artist humanoid robot is the lack of feedback on the error that occurs during the drawing process. The contribution of this research is the development of a humanoid robot artist with drawing error correction capability. Based on our previous work with open-loop control pen-and-ink humanoid robot artist, we have implemented a closed-loop visual servoing approach to address this problem. Our experimental results show that this approach is sufficient to correct drawing errors that occur due to mechanical limitation of a robot.

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