Adaptive Traffic Controller Based On Pre-Timed System

Adaptive traffic controller systems based on image processing have been developed widely. Nevertheless, in a developing country, the systems often could not be easily applied because all types of vehicle use the same road. Therefore, to overcome the problem, the new concept of the systems is proposed. The systems were developed from a pre-timed traffic controller system that based on AVR microcontroller. By default, the systems use the signal-timing plans to control the vehicle flow. To accommodate the traffic variations, a new method of vehicle detection has been built. The method calculated an intensity histogram standard deviation of the image representing a detection area to determine traffic density of each intersection lane. The systems modified the green-time of each lane based on the traffic density. The method could detect all types of vehicles and work properly in a day and a night time

Pre-Timed and Coordinated Traffic Controller Systems Based on AVR Microcontroller

The major weaknesses of traffic controllers in Indonesia are unable to accommodate the variety of traffic volume and unable to be coordinated. To solve the problem, a pre-timed and coordinated traffic controller system is build. The system consists of a master and a local controller. Each controller has a database containing signal-timing plans that would be allocated to manage vehicle flows. To synchronize the signal-timing, the master controller sends the synchronization data to the local controller wirelessly and the local controller shifts the end of a cycle by adding or subtracting the green interval of any phases. The transition time for synchronization only takes one to several cycles. The algorithm for controlling the traffic including coordination can be done by an AVR microcontroller. Memory usage of the microcontroller is lower than 10% meanwhile the CPU utilization is no more than 1%, thus the systems could be widely developed

A Novel Boost-Buck Converter Architecture for Improving Transient Response and Output-Voltage Ripple

Buck-boost converters are widely used in the development of DC-DC converters. Several techniques and algorithms have been introduced to improve the transient response of buck-boost converters. However, due to the opposite trends of the output current change and the output voltage change, undershoot or overshoot in the output voltage still seems to be inevitable. In order to overcome this problem, a novel boost-buck converter architecture is proposed to build a fast transient response DC-DC converter. The converter consists of a cascaded configuration of the boost and buck stages. The boost stage converts the input voltage to the shared capacitor voltage and the buck stage supplies energy to the load by converting the shared capacitor voltage to the output voltage. By harnessing the energy stored in the shared capacitor, the transient response of the boost buck converter can be improved to 2 µs in a step-up load current change of 1 A with an output-voltage ripple of 15 mV

Study of Permanent Magnet Synchronous Motor With LQG Controller and Observer On The Hydraulic Pump System

In today's aircraft industry, the flight control system and landing gear system cannot be separated from the role of the hydraulic technology system. As the prime mover of the hydraulic pump or actuator hydraulic system, a permanent magnet synchronous motor (PMSM) is used. This PMSM is a substitute for the role of conventional combustion engines, and PMSM is considered to have several advantages in increasing performance and efficiency. This research will develop a system to find parameter values for Linear Quadratic Gaussian (LQG) controllers in a hydraulic pump system that is installed as a load from PMSM and then observe and analyze the performance of the response of the synchronous motor system, namely in the form of changes in rotor rotation speed, torque electric power, and stator current on the q-axis. The results of the research on the characteristics of the PMSM implemented in the hydraulic pump system show that the LQG controller is more optimal when compared to the observer controller. The LQG controller is known to have a faster transient response, which is indicated by the value of the settling time improvement at no load, namely 116.67% for the observer controller and 364.705% without the controller. Then when the synchronous motor serves the nominal load, the rotational speed of the rotor produced in the steady state becomes 8.29% faster than the observer controller and 74.49% without the controller. This rotor's rotational speed affects the time the actuator needs to extend and retract motion

SIFAT-SIFAT ALIRAN SLUG DITINJAU DARI KARAKTERISTIK LOKAL (VISUALISASI, LIQUID HOLD-UP DAN SIGNAL PROCESSING) PADA PIPA HORIZONTAL

The visualization studies and the signal processing of the liquid hold-up data of the air-water slug two-phase flow in a horizontal pipe were conducted simultaneously. The liquid hold-up data were obtained by using a constant electric current method (CECM). The principle of this method is on the basis of the conductivity ratio of the two-phase components. The visualization study was carried-out from the analyzing of the visual data obtained from the video camera. As a result, it is found that: (1) the length of the air and water plug increases as the increase of the air superficial velocity, meanwhile it decreases as the water superficial velocity increases, (2) the average of liquid hold-up increases as the increase of the air water velocity, meanwhile it decreases as the air superficial velocity increases, (3) the velocity of the gas plug, slug, and wave velocity were affected by both of the water and air superficial velocities, (4) the slug wave frequency increases with water flow rate, but does not depend on air flow rate

The Visualization Study on the Slug Flow Mechanisms of the Air-Water Two-Phase in a 50 mm Horizontal Pipe

The slug flow phenomena are often encountered in various industrial applications such as petroleum, process, and power plant. The presence of slug flow should be avoided as it causes structural damage due to resonance, corrosion and pipes blast. From the view point of multiphase flow, the understanding of the slug initiation mechanism is very important in pipeline design. This research is conducted using horizontal transparent acrylic pipes with diameters of 50 mm with a variation on the superficial velocity of water between 0,1 m/s and 0,77 m/s and superficial velocity of air between 0,31 m/s and 6,2 m/s. In the present experimental study, the slug initiation mechanisms was explained by visual observation by using high speed video cameras. As the results, the slug flow initiation mechanism were clarified. Furthermore, the proposed of flow initiation map was introduced

Penentuan Orientasi dan Translasi Gerakan UAV Menggunakan Data Fusion Berbasis Kalman Filter

Navigation system is essential in estimating the orientation and translation motion of UAV. The system can utilize data from several sensors and devices, e.g. MIMU and GPS. The orientation of UAV can be precisely calculated by means of data from accelerometer and magnetometer when both sensors are in static state. Meanwhile, under dynamic conditions, the orientation can be more precisely predicted through the use of gyroscope sensor data. In order to attain a robust navigation system, a data fusion based on Kalman filter is built to estimate the orientation from the accelerometer, gyroscope, and magnetometer sensors. Moreover, for sake of achieving high accuracy, the filter will further correct the orientation by giving a higher weight to the data from accelerometer and magnetometer sensors when the UAV is in static condition. In the case of its position, the UAV position will be estimated by performing data fusion of MIMU and GPS data. Based on the experiments, it could be showed that data fusion based on Kalman filter provided more accurate results of orientation and position of UAV. The result of orientation based on gyroscope sensor data has an average error of 18.12°, while those obtained by accelerometer and magnetometer sensors data is 1.3°. Furthermore, by using the data fusion based on Kalman filter, the error of orientation predicted by combining data from accelerometer, magnetometer, and gyroscope will decrease to 0.87°

Tinjauan Penerapan Teknik Olah Citra untuk Mempelajari Perilaku Antarmuka pada Fenomena Dua-fase Gas-cairan

Perilaku antarmuka (interface) gas-cairan adalah suatu parameter yang sering dipakai untuk mempelajari karakteristik fenomena dua-fase gas-cairan. Fenomena tersebut umum terjadi di berbagai proses industri, baik ketika ada proses perpindahan kalor dan massa ataupun tidak (proses adiabatik). Oleh karena itu, suatu pengembangan teknik dan metode untuk mempelajari tanpa mengganggu fenomena fisis tersebut mutlak diperlukan. Teknik olah citra adalah salah satu metode yang digunakan untuk mempelajari perilaku antarmuka berdasarkan data visual yang diperoleh melalui sebuah perangkat perekam citra. Keunggulan teknik ini adalah kemampuannya untuk mengambil dan mengolah beragam data visual dengan berbagai kompleksitas tanpa mengganggu fenomena fisis yang dipelajari. Baru-baru ini, Grup Riset Mekanika Fluida Teknik Mesin Universitas Gadjah Mada sedang mengembangkan teknik olah citra untuk mempelajari fenomena dua-fase gas-cairan pada kondisi adiabatik maupun pada kondisi terjadi proses perpindahan kalor dan massa. Untuk tujuan pengembangan teknik olah citra, suatu tinjauan perlu dilakukan terkait penerapan teknik ini dalam sebuah studi kasus fenomena dua-fase gas-cairan. Juga, faktor-faktor yang mempengaruhi bagus tidaknya hasil proses olah citra akan dibahas. Pada makalah ini, berbagai rekomendasi dipaparkan guna pengembangan teknik olah citra, baik dari segi pengambilan data visual hingga proses pengolahan citra untuk mendapatkan hasil akhir yang lebih baik

Tinjauan Penerapan Teknik Olah Citra untuk Mempelajari Perilaku Antarmuka pada Fenomena Dua-fase Gas-cairan

Perilaku antarmuka (interface) gas-cairan adalah suatu parameter yang sering dipakai untuk mempelajari karakteristik fenomena dua-fase gas-cairan. Fenomena tersebut umum terjadi di berbagai proses industri, baik ketika ada proses perpindahan kalor dan massa ataupun tidak (proses adiabatik). Oleh karena itu, suatu pengembangan teknik dan metode untuk mempelajari tanpa mengganggu fenomena fisis tersebut mutlak diperlukan. Teknik olah citra adalah salah satu metode yang digunakan untuk mempelajari perilaku antarmuka berdasarkan data visual yang diperoleh melalui sebuah perangkat perekam citra. Keunggulan teknik ini adalah kemampuannya untuk mengambil dan mengolah beragam data visual dengan berbagai kompleksitas tanpa mengganggu fenomena fisis yang dipelajari. Baru-baru ini, Grup Riset Mekanika Fluida Teknik Mesin Universitas Gadjah Mada sedang mengembangkan teknik olah citra untuk mempelajari fenomena dua-fase gas-cairan pada kondisi adiabatik maupun pada kondisi terjadi proses perpindahan kalor dan massa. Untuk tujuan pengembangan teknik olah citra, suatu tinjauan perlu dilakukan terkait penerapan teknik ini dalam sebuah studi kasus fenomena dua-fase gas-cairan. Juga, faktor-faktor yang mempengaruhi bagus tidaknya hasil proses olah citra akan dibahas. Pada makalah ini, berbagai rekomendasi dipaparkan guna pengembangan teknik olah citra, baik dari segi pengambilan data visual hingga proses pengolahan citra untuk mendapatkan hasil akhir yang lebih baik