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A Low-Cost Obstacle Avoidance System Prototype for Autonomous Wheelchairs Using a Servo-Mounted Ultrasonic Sensor
(2026-01-01)
Jongchanachavawat, Wirote
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Mingmuang, Noppon
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Ployjirapas, Chayut
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Nanan, Kwanchai
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Oiumekha, Kamonwan
This research presents the development of a low-cost obstacle avoidance prototype designed for mobile robotic applications, with a potential use case in autonomous wheelchairs. The system utilizes a single ultrasonic sensor mounted on a servo motor to perform multi-directional distance scanning, allowing the robot to detect and avoid obstacles in real time. An Arduino-based control algorithm interprets distance measurements at four predefined angles (30°, 60°, 120°, and 150°), enabling the robot to make navigation decisions including forward movement, turns, and retreating actions. The system was tested under various conditions: with obstacles in front, in front-left, and in all directions (front, left, and right). Results showed a 100% success rate in the simple frontal obstacle scenario, 80% in the front-left obstacle case, and 60% in the most complex environment with obstacles on three sides. The primary cause of failure was the sensor’s limitation in detecting very close objects (less than 2 cm). The findings confirm the feasibility of implementing this single-sensor approach in low-cost assistive mobility devices. The prototype demonstrates effective navigation capabilities and provides a practical foundation for future development of intelligent obstacle-avoidance systems for autonomous wheelchairs.
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Wireless Automated Exhibition System: Convenient Mobility at Low Cost
(2025-01-01)
Hirunwijitporn, Nirumol
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Jongchanachavawat, Wirote
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Bunyarittikit, Suphat
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Mingmuang, Noppon
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Roopkom, Ittipat
The application of wireless automatic exhibition system for event promotion facilitates the organization of exhibition-related activities by enabling automated control of exhibition displays. This system eliminates the need for allocating personnel to monitor the exhibition, thus reducing the cost of hiring exhibition attendants. From this research, it is possible to create a low-cost wireless automatic exhibition display system that is convenient for use in various events and exhibitions, especially when there are numerous booths involved. The system utilizes infrared sensors to detect visitors within a range of 90 cm, enabling accurate visitor counting. Once the desired number of visitors is reached, the exhibition will be displayed immediately. Additionally, the system can detect exiting visitors while the exhibition is ongoing. When the specified visitor count is met, the exhibition display will stop instantly. Due to these features, this wireless automatic exhibition system is affordable, easily portable, and suitable for various events and exhibitions. It is user-friendly and convenient for deployment.
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Current-Mode First-Order Versatile Filter Using Translinear Current Conveyors with Controlled Current Gain
(2023-07-01)
Kumngern, Montree
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Jongchanachavawat, Wirote
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Phatsornsiri, Punnavich
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Wongprommoon, Natapong
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Khateb, Fabian
This paper offers a new current-mode first-order versatile filter employing two translinear current conveyors with controlled current gain and one grounded capacitor. The proposed filter offers the following features: realization of first-order transfer functions of low-pass, high-pass, and all-pass current responses from single topology, availability of non-inverting and inverting transfer functions for all current responses, electronic control of current gain for all current responses, no requirement of component-matching conditions for realizing all current responses, low-input impedance and high-output impedance which are required for current-mode circuits, and electronic control of the pole frequency for all current responses. The proposed first-order versatile filter is used to realize a quadrature sinusoidal oscillator to confirm the advantage of the new topology. To confirm the functionality and workability of new circuits, the proposed circuit and its application are simulated by the SPICE program using transistor model process parameters NR100N (NPN) and PR100N (PNP) of bipolar arrays ALA400-CBIC-R from AT&T.
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1.2 V differential difference current conveyor using MIGD MOST technique and its applications
(2023-01-01)
Kumngern, Montree
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Khateb, Fabian
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Phatsornsiri, Punnavich
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Jongchanachavawat, Wirote
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Kulej, Tomasz
This paper presents a new differential difference current conveyor (DDCC), realized using multiple-input gate-driven MOS transistor (MIGD MOST) technique. The application of MIGD MOST can reduce the number of differential pairs in the input stage of the DDCC, thus simplifying its overall structure. Unlike previous DDCC, the output stage of the circuit operates in super class-AB, that offers low static power consumption, high load driving capability and improved gain-bandwidth product (GBW).The proposed DDCC can work with the supply voltage of 1.2 V and consumes 44.2 μW of power. The proposed DDCC has been used to realize a versatile circuit that can work as a universal filter or a quadrature oscillator into a single topology. When the circuit works as a universal filter, it can realize low-pass, band-pass, high-pass, band-stop and all-pass voltage responses. The natural frequency and the quality factor of these responses can be orthogonally controlled. When the circuit works as a quadrature oscillator, the condition and the frequency of oscillators can be orthogonally controlled. The proposed MIGD DDCC and the proposed universal filter and quadrature oscillator have been simulated with SPICE, using 0.18 μm CMOS process parameters to prove the functionality and workability of the new circuits.
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Application of Ultrasonic Sensor and IR Sensor in Automatic Alcohol Hand Sanitizer
(2023-01-01)
Jongchanachavawat, Wirote
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Sungkongmueng, Bureerak
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Inyasri, Chaleedol
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Roopkom, Ittipat
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Mingmuang, Noppon
Hygiene is necessary to maintain human health. Hygiene keeps the body clean and free from germs, preventing the spread of diseases, which has been especially important during the COVID-19 pandemic. For this reason, we designed automatic alcohol hand sanitizers (AAHSs): one with an IR sensor and one with an ultrasonic sensor. The sanitizers will help prevent germs from spreading via the hands of people because no part of each device need be touched during its use. The AAHS with the ultrasonic sensor has various advantages over that with the IR sensor: it is 32% cheaper to produce, easier to configure and maintain, has a higher average score for user satisfaction, is smaller and more portable, and can use rechargeable batteries. In addition, its low cost makes it more suitable for commercialization. It can also be installed both outdoors and indoors. In an outdoor test, it was demonstrated to operate flawlessly. This paper includes useful information on the components of the AAHSs with the two types of sensor and an evaluation of their performance using confusion matrices.
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Current-Mode Universal First-Order Analog Filter Using CCCIIs
(2023-01-01)
Phatsornsiri, Punnavich
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Torteanchai, Usa
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Wongprommoon, Natapong
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Kumngern, Montree
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Jongchanachavawat, Wirote
This paper presents a new current-mode first-order universal analog filter using current-controlled current conveyors (CCCIIs). The proposed circuit can realize first-order sections such as all-pass, low-pass, high-pass filters with both non-inverting and inverting transfer functions into single topology. The pole frequency of these filters can be controlled electronically. The output terminals possess high impedance level which is required for cascading of current-mode circuits. The proposed analog filter is verified using SPICE simulation. The CCCII has been simulated using the 0.18 µm CMOS technology with a supply voltage of 1.8 V. The simulation result can show that it agrees well with theory.
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Multiple-Input Multiple-Output Universal Filter Using DDTAs
(2022-01-01)
Suksaibul, Pichai
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Torteanchai, Usa
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Manman, Somsak
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Jongchanachavawat, Wirote
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Kumngern, Montree
This paper presents a multiple-input multiple-output universal biquadratic filter using differential difference transconductance amplifiers. The variant filtering responses can be obtained by appropriately applying input signals and appropriately choosing output terminals. The voltage-mode filter possesses both high-input and low-output impedances. The proposed filter provides five standard filtering responses. The natural frequency can be controlled electronically, and the quality factor can be controlled orthogonally. The performance of the proposed filter is confirmed using PSPICE simulation based on 0.18 µm CMOS technology from TSMC.
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Mixed-Mode Universal Filter Using Differential Difference Transconductance Amplifiers
(2022-01-01)
Suksaibul, Pichai
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Torteanchai, Usa
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Kumngern, Montree
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Jongchanachavawat, Wirote
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Burapattanasiri, Bancha
This paper presents a new mixed-mode universal biquad filter based on differential difference transconductance amplifiers (DDTAs). This work will be expressed that many filtering functions with electronic control of the natural frequency can be obtained using DDTA-based circuit. The topology provides voltage-mode (VM), current-mode (CM), transimpedance-mode (TIM), transadmittance-mode (TAM) transfer functions into single topology and each transfer function offers five standard filtering functions. The performance of the proposed topology is carried out using PSPICE simulators based on 0.18 μm CMOS technology from TSMC. The simulation result shows that it can confirm the proposed topology.
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1.2 v Differential Difference Current Conveyor Using MIGD MOST Technique
(2022-01-01)
Phatsornsiri, Punnavich
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Torteanchai, Usa
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Rattanasuttikan, Manurak
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Jongchanachavawat, Wirote
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Kumngern, Montree
This paper presents a new differential difference current conveyor (DDCC) using multiple-input gate-driven MOS transistor (MIGD MOST) technique. The MIGD MOST technique can be reduced the number of transistor differential pair. The differential input stage is implemented by flipped voltage follower to obtain low power supply requirements. Thus, the proposed DDCC is capable to working with a supply voltage of 1.2 V and it consumes a 44.2 μW of power dissipation. The simulations were performed with PSPICE using the 0.18 μm CMOS technology to prove the workability of the new circuit.
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0.3 v Fully Differential Current Conveyor Using MIBD-DT MOST technique
(2022-01-01)
Kumngern, Montree
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Torteanchai, Usa
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Wongprommoon, Natapong
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Jongchanachavawat, Wirote
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Tooprakai, Siraphop
This paper presents a new fully differential second-generation current conveyor (FDCCII) using multiple-input bulk-driven dynamic threshold voltage MOS transistor (MIBD-DT MOST) technique. This FDCCII, the MOST techniques such as the multiple-input (MI), bulk-driven (BD) and dynamic threshold voltage (DT) have been used. The MIBD can be reduced the number of differential pair of FDCCII and the DT-MOST technique can be reduced the power supply requirement. Thus, the proposed FDCCII is capable to working with a supply voltage of 0.3 V and it consumes a 0.132 uW of power dissipation. The simulations were performed with SPICE program using the 0.18 um CMOS technology. To prove the workability of the new circuit, the proposed FDCCII has been used to realize universal filter.

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