• Transactions of the Korean Society of Mechanical Engineers B
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• v.30 no.2 s.245
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• pp.110-116
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• 2006

A syringe pump or a device using high electric voltage has been used for controlling flows inside a LOC (lab-on-a-chip). Compared to LOC, however, these microfluidic devices are large and heavy that they are burdensome for a portable ${\mu}-TAS$ (micro total analysis system). In this study, a new flow control technique employing pressure regulators and pressure chambers was developed. This technique utilizes compressed air to control the micro-scale flow inside a LOC, instead of a mechanical actuator or an electric power supply. The pressure regulator controls the output air pressure by adjusting the variable resistor attached. We checked the feasibility of this system by measuring the flow rate inside a capillary tube of $100{\mu}m$ diameter in the Re numbers ranged from 0.5 to 50. In addition, the performance of this flow control system was compared with that of a conventional syringe pump. The developed flow control system was found to show superior performance, compared with the syringe pump. It maintains automatically the: air pressure inside a pressure chamber whether the flow inside the capillary tube is on or off. Since the flow rate is nearly proportional to the resistance, we can control flow in multiple microchannels precisely. However, the syringe pump shows large variation of flow rate when the fluid flow is blocked in the microchannel.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1272-1277
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• 2005

In this study, we wolud be developed the fuzzy controlled PGO that controlled the flexion and the extension of each PGO's joint using the bio-signal and FSR sensor. The PGO driving system is to couple the right and left sides of the orthosis by specially designed hip joints and pelvic section. This driving system consists of the orthosis, sensor, control system. An air supply system of muscle is composed of an air compressor, 2-way solenoid valve(MAC, USA), accumulator, pressure sensor. Role of this system provide air muscle with the compressed air at hip joint constantly. According to output signal of EMG sensor and foot sensor, air muscles and assists the flexion of hip joint during PGO gait.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.24 no.4
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• pp.129-134
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• 2024

In this paper, This paper is a liquid droplet discharge system using a water level sensor that can linearly detect changes in water level through experiments with an infrared sensor, a laser sensor, an ultrasonic sensor, and a capacitance sensor. SMPS, regulator 5V, and LDO 3.3V were designed for power supply. A water level sensor input ADC circuit and microprocessor were used. Solenoid valve control, pump output control unit for positive/negative pressure generation, CAN, Ethernet, UART communication, and USB for industrial communication were used. The change in pressure was confirmed through the change in water level, the change in pressure was minimized, and a system for discharging liquid droplets was implemented.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.5
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• pp.79-88
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• 2020

This paper propose the method to drive a solar panel cleaning robot efficiently on an inclined panel using vacuum pad pressure. In this method, the rubber pads using the vacuum pressure are used to attach robot body to the panel surface. By applying the linkage mechanism to the vacuum pads, it was possible to reduce robot weight and power consumption and to prevent slipping of the robot. In addition, the use of solenoid valves, proximity sensors, and encoders to detect movement of the robot body and the control of the pad pressure dedicate to the driving of the robot on an inclined panel. In order to move the robot forward, the operation sequence of multiple solenoid valves was completed, and the six vacuum pads mounted to both legs were accurately controlled to form vacuum and atmospheric pressure in right order so that the robot could move forward without slipping. At last, it was confirmed through experiments that straight-forward moving and rotational movement could be performed up to 36 degrees of inclination angle of solar panel.

• Proceedings of the KSME Conference
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• 2001.06e
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• pp.595-600
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• 2001

Thermal mass flow meter(TMF) and thermal mass flow controller(MFC) were used to measure and to control the mass flow rate of gases. TMF and MFC were designed for specified working pressure and gas. For the case of different working pressure and gases, the flow rate measurement accuracy decreased dramatically. In this study, a TMF and MFC was tested with three different gases and pressure range from 0.2 MPa up to 1.0 MPa. Effect of specific heat causes to increase flow measurement error as much as ratio of specific heat compared with reference gas. Changing of pressure causes to increase flow rate measurement error about -0.2% as the working pressure decreased 0.1 MPa. Response time of MFC was below 3.12 s for the case of increasing of flow rate. But the response time was increased up to 6.92 s for the case of decreasing of flow rate. When the solenoid valve was fully closed, a initial delay time of output of MFC was increased up to 1.36 s.

• Journal of ILASS-Korea
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• v.8 no.3
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• pp.33-40
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• 2003

The low-emission and high-performance diesel combustion is an important issue in the combustion research community, In order to understand the detailed diesel flame involving the complex physical processes, it is quite desirable to diesel spray dynamics, auto-ignition and spray flame propagation. Dynamics of fuel spray is a crucial element for air-fuel mixture formation, flame stabilization and pollutant formation, In the present study, the diesel RCM (Rapid Compression Machine) and the Electric Control injection system have been designed and developed to investigate the effects of injection pressure, injection timing, and intake air temperature on spray dynamics and diesel combustion processes, In terms of the macroscopic spray combustion characteristics, it is observed that the fuel jet atomization and the droplet breakup processes become much faster by increasing the injection pressure and the spray angle, With increasing the cylinder pressure, there is a tendency that the of spray pattern in the downstream region tends to be spherical due to the increase of air density and the corresponding drag force, Effects of intake temperature and injection pressure on auto-ignition is experimently analysed and discussed in detail.

• Proceedings of the KSME Conference
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• 2000.04b
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• pp.447-452
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• 2000

The low-emission and high-performance diesel combustion is an important issue in the combustion research community. In order to understand the detailed diesel flame field involving the complex Physical Processes, It Is quite desirable to study diesel spray dynamics, auto-ignition and spray flame propagation. Dynamics of fuel spray is a crucial element for air-fuel mixture formation flame stabilization and pollutant formation. In the present study, the diesel RCM (Rapid Compression Machine) and the Electric Control injection system have been designed and developed to investigate the effects of injection Pressure, injection timing, and intake air temperature on spray dynamics and diesel combustion processes. In terms of the macroscopic spray combustion characteristics it is observed that the fuel jet atomization and the droplet breakup processes become much faster by increasing the injection pressure and the spray angle. With increasing the cylinder pressure there is a tendency that the shape of spray pattern in the downstream region tends to be spherical due to the increase of air density and the corresponding drag force. Effects of intake temperature and injection pressure on auto-ignition is experimently analysed and discussed in detail.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.22 no.3
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• pp.663-670
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• 1998

Most of feedback shift controllers developed in the past have fixed control parameters tuned by experts using a trial and error method. Therefore, those controllers cannot satisfy the best control performance under various driving conditions. To improve the shift quality under various driving conditions, a new self-organizing controller(SOC) that has an optimal control performance through self-learning of driving conditions and driver's pattern is designed in this study. The proposed SOC algorithm for the shift controller uses simple descent method and has less calculation time than complex fuzzy relation, thus makes real-time control passible. PCSV (Pressure Control Solenoid Valve) control current is used as a control input, and turbine speed of the torque converter is used indirectly to monitor the transient torque as a feedback signal, which is more convenient to use and economic than the torque signal measured directoly by a torque sensor. The results of computer simulations show that an apparent reduction of shift-transient torque is obtained through the process of each run without initial fuzzy rules and a good control performance in the shift-transient torque is also obtained.

• Journal of Energy Engineering
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• v.22 no.4
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• pp.394-398
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• 2013

At present, using of electromagnetic control valve (ECV) in external variable displacement swash plate type compressor is a common issue. Solenoid operated ECV controls vehicle air conditioning system through a pulse width modulation (PWM) input signal that supplied from an external source. Different port pressure controls the swash plate movement inside the compressor at certain angles that finally determines the refrigerant flow rate to the vehicle compartment for passengers comfort. In this paper, crankcase pressure flow (Pc flow) is calculated with some ECV samples with corresponding to amount of variable supply of current ranges from 0.20Amp to 0.95Amp.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.11a
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• pp.282-283
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• 2008

According to the development of vehicle technique, the improved NVH performance is required in the vehicle which have the high effectiveness and the high output of the powertrain. This vehicle has to be adapted to active engine mounting system to reduce the vibration in accordance with various vehicle information. The pneumatic active engine mounting system is consist with engine mount, solenoid valve, air tank and control unit totally. The important technique of this system is to reduce the vibration by the air pressure. This paper contains the development process of the pneumatic active engine mounting system and confirm the performance of this system test and vehicle test.