scholarly journals Active Vibration Control in Microgravity Environment

1988 ◽  
Vol 110 (1) ◽  
pp. 30-35 ◽  
Author(s):  
C. H. Gerhold ◽  
R. Rocha
Keyword(s):  
Control System ◽  
Flow Rate ◽  
Aerodynamic Drag ◽  
Space Station ◽  
Control Process ◽  
Microgravity Environment ◽  
Damping Factor ◽  
Air Jets ◽  
Air Jet ◽  
Enclosed Space

The low gravity environment of the Space Station is suitable for experiments or manufacturing processes which require near zero-g. Such experiments are packaged to fit into rack-mounted modules approximately 106.7 cm (42 in.) wide × 190.5 cm (75 in.) high × 76.2 cm (30 in.) deep. The mean acceleration level of the Space Station is expected to be on the order of 10−6 g (9.81 × 10−6 m/s2). This steady state acceleration is a superposition of aerodynamic drag, centripetal forces, and the gravitational attraction of the earth and of the moon. Excitations such as crew activity or rotating unbalance of nearby equipment can cause momentary disturbances to the vibration-sensitive payload which degrade the microgravity environment and compromise the validity of the experiment or process. Isolation of the vibration-sensitive payload from structure-borne excitation is achieved by allowing the payload to float freely within an enclosed space. Displacement-sensitive transducers indicate relative drift between the payload and the surrounding structure. Small air jets fixed to the structure direct air flow to impinge on the payload. This thrust force keeps the payload centered within the enclosed space. The mass flow rate of the air jets is controlled such that the resultant acceleration of the payload is less than a criterion of 10−5 g. It is expected that any power or fluid lines that connect the experiment to the Space Station structure can be designed such that their transmitted vibration levels are within the criterion. An experiment has been fabricated to test the validity of the active control process and to verify the flow and control parameters identified in a theoretical model. Zero-g is approximated in the horizontal plane using a low-friction air-bearing table. An analog control system has been designed to activate calibrated air jets when displacement of the test mass is sensed. The experiment demonstrates that the air jet control system introduces an effective damping factor to control oscillatory response. The amount of damping as well as the flow parameters, such as pressure drop across the valve and flow rate of air, are verified by the analytical model.

Vibration Isolation in a Microgravity Environment

1993 ◽  
Vol 115 (4) ◽  
pp. 477-483
Author(s):  
R. M. Alexander ◽  
C. H. Gerhold ◽  
C. B. Atwood ◽  
J. F. Cordera
Keyword(s):  
Vibration Isolation ◽  
Center Of Mass ◽  
Space Station ◽  
Microgravity Environment ◽  
Isolation System ◽  
Air Jet ◽  
Surrounding Structure ◽  
Jet Control ◽  
Oscillatory Response ◽  
The Mathematical Model

Many in-space research experiments require the microgravity environment attainable near the center of mass of the proposed space station. Since dynamic disturbances to the surrounding structure may undermine an experiment’s validity, isolation of these experiments is imperative. This paper summarizes analytical and experimental work accomplished to develop an isolation system which allows the pay load to float freely within a prescribed boundary while being kept centered with forces generated by small jets of air. An experimental setup was designed and constructed to simulate the microgravity environment In the horizontal plane. Results demonstrate the air jet control system to be effective in managing payload oscillatory response. An analytical model was developed and verified by comparing predicted and measured payload response. The mathematical model is then used to investigate payload response to disturbances likely to be present in the space station.

scholarly journals Design of monitor system and tube fluid’s rate controller based on pressure sensor mpx5100dp and control valve

2021 ◽  
Vol 2 (1) ◽  
pp. 19-23
Author(s):  
Reza Ardiansyah Maheda ◽  
Samsul Hidayat ◽  
Nugroho Adi Pramono
Keyword(s):  
Control System ◽  
Flow Rate ◽  
Pressure Sensor ◽  
Control Process ◽  
Control Valve ◽  
Monitor System ◽  
Servo Motor ◽  
Industrial Operations ◽  
Operations Control ◽  
And Control

Control system is a major component in the industrial operations control process. In some industries that make use of chemicals, an error variables or parameters settings can cause some damage. For the environment or the industry itself. So, utilization and development in this field is an awful lot to do. This control system is designed to measure and control the flow rate of the fluid in the pipes. This tool is composed by using a pressure sensor MPX5100dp as the primary sensor and also the servo motor that became the controlling actuator faucets. The results showed that this system can control the fluid's flow rate according to what expected. For monitoring, the system can can determine the rate changes that occur in the pipe. This tool can measure the pressure of 100kPa and rotate the actuator up to faucets with a range of more or less 5 degree.

scholarly journals Vibration Isolation in a Microgravity Environment

1991 ◽  
Author(s):  
Richard M. Alexander ◽  
Carl H. Gerhold ◽  
Clay B. Atwood ◽  
Joseph F. Cordera
Keyword(s):  
Vibration Isolation ◽  
Center Of Mass ◽  
Space Station ◽  
Microgravity Environment ◽  
Isolation System ◽  
Air Jet ◽  
Surrounding Structure ◽  
Jet Control ◽  
Oscillatory Response ◽  
The Mathematical Model

Abstract Many in-space research experiments require the microgravity environment attainable near the center of mass of the proposed Space Station. Since dynamic disturbances to the surrounding structure may undermine an experiments validity, isolation of these experiments is imperative. Analytical and experimental work has been completed in developing an isolation system which allows the payload to float freely within a prescribed boundary while being kept centered with forces generated by small jets of air. An experimental setup was designed and constructed to simulate the microgravity environment in the horizontal plane. Results demonstrate the air jet control system to be effective in managing payload oscillatory response. An analytical model was developed and verified by comparing predicted and measured payload response. The mathematical model is used to predict dynamic payload response to disturbances likely to be present in the Space Station. The figure shown below is a schematic of the test setup to be discussed during the presentation.

Integration of controllable scientific equipment into the Russian Segment of the International Space Station

2020 ◽  
pp. 66-75
Author(s):  
Diana M. AYUKAEVA ◽  
Fedor A. VORONIN ◽  
Mikhail A. POLUARSHINOV ◽  
Mikhail A. KHARCHIKOV
Keyword(s):  
Control System ◽  
International Space Station ◽  
Electromagnetic Compatibility ◽  
Space Station ◽  
Space Experiment ◽  
Successful Operation ◽  
International Space ◽  
Scientific Equipment ◽  
Cargo Transportation ◽  
And Control

The paper discusses the process of integrating scientific equipment into the Russian Segment of the International Space Station (ISS RS) to conduct space experiment using the ISS IS information and control system. The paper addresses the stages in ground processing of scientific equipment that are critical for its successful operation after delivery to the ISS RS: tests on the hardware (vibration and hydraulic tests, electromagnetic compatibility tests, incoming inspection), development of the software for the equipment using ground debugging facility and conducting integrated tests in the checkout facility. It points out the need to update the existing stages of ground preparations for experiments to reduce the hardware ground processing time. Taking as examples the space experiment Terminator and experiments conducted using cargo transportation spacecraft Progress, the paper resents results obtained through the use of the described approach. Key words: information and control system, scientific equipment, space experiment, International Space Station, logistics spacecraft Progress, microgravity.

Application of PID in Controllable Pitch Propeller of a Multipurpose Ocean Tug

2013 ◽  
Vol 464 ◽  
pp. 253-257
Author(s):  
Hui Fang Chen
Keyword(s):  
Control System ◽  
Automatic Control ◽  
Automatic Control System ◽  
High Reliability ◽  
Control Process ◽  
Good Control ◽  
Control Performance ◽  
Hardware Configuration ◽  
Design Idea ◽  
And Control

This paper takes the automatic control system of controllable pitch propeller in a multipurpose ocean tug as an example to describe the application of the S7-200 series PLC in the control system of 4500 horse power controllable pitch propeller in detail. The principle of control system is addressed, as well as the hardware configuration, the design idea of the main software and control process. The system shows high reliability, accuracy and good control performance in practical in practical running.

The Empirical Research on Automatic Control System of Training Information

2013 ◽  
Vol 427-429 ◽  
pp. 488-491
Author(s):  
Chuan Jin ◽  
Xiao Mei Wang ◽  
Ke Liu Yang
Keyword(s):  
Control System ◽  
Control Method ◽  
Control Process ◽  
Acquisition Training ◽  
Training Methods ◽  
Information Control ◽  
Basketball Players ◽  
Training Scheme ◽  
Evaluation Scores ◽  
Training Control

At present, basketball training needs more scientific training methods and techniques. In order to obtain these training methods, it needs to acquisition training information in the process of basketball training. Therefore, in view of basketball training to establish information control system, research on basketball players training characteristics and the law of motion in the process of basketball training, using control theory method to carry out information processing and analysis, and then the use of scoring methods carry out the authority score evaluation on basketball trainings influencing factors, according to the weight values, these are obtained on the basis of the score, then to carry out add sum, finally to obtain the evaluation scores of basketball training information control system. And then according to the weight value, to undertake an analysis of the basketball training control process, the basketball training information control method is put forward. The analysis results show that information control system is mainly manifested in the basketball training information collection and transmission, training scheme decision of coaches decision system as well as the feedback of decision information, which will complete the whole system construction of basketball training information control.

Twin Pulsating Jets Impingement Heat Transfer for Fuel Preheating in Automotives

2014 ◽  
Vol 663 ◽  
pp. 322-328 ◽  
Author(s):  
Ali Ahmed Gitan ◽  
Rozli Zulkifli ◽  
Kamaruzaman Sopian ◽  
Shahrir Abdullah
Keyword(s):  
Heat Transfer ◽  
Ignition Process ◽  
Pulsation Frequency ◽  
Ir Camera ◽  
Copper Target ◽  
Air Jets ◽  
Air Jet ◽  
Impingement Heat Transfer ◽  
Pulsating Jet ◽  
Pulsating Jets

The problem of environmental pollution and depletion of fossil fuel can be reduced in automotives by using an alternative bio-fuel and improve the ignition process in engine. Both solutions need to use the fuel preheating technique. This work presents the idea of fuel preheating by using exhaust impingement on the fuel tank. Heat transfer between twin pulsating hot air jets and flat copper target was investigated as an application for preheating of automotive fuel to improve ignition process in the engine. The nozzle of 20 mm was used to produce air jet of Reynolds number, Re ≃ 5500 and a temperature of 54°C. The impinged target was imposed to still air surrounding at temperature of 24°C. Pulsating frequencies of 10-50 Hz were applied on air jets by using twin pulsating jet mechanism. The effect of pulsation frequency on heat transfer was measured using IR camera and heat flux-temperature micro foil sensor. The results obtained by both of these methods showed well agreement. Also, the results revealed significant influence of flow rate difference between steady and pulsating jet cases. In addition, the highest Nusselt number, Nu ≃ 7.2, was obtained at pulsation frequency of 20 Hz.

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