Single Input Fuzzy Logic Controller For Yaw Control Of Underwater Remotely Operated Crawler

Underwater Remotely Operated Crawler (ROC) is a class of the Unmanned Underwater Vehicle (UUV) that is tethered, unoccupied, manoeuvres on the seabed and remotely operated by a pilot from a platform. Underwater characteristic parameters such as added mass, buoyancy, hydrodynamic forces, underwater currents, including pressure could considerably affect and reduce the mobility of the ROC. The challenges faced by the ROCs are that the needs to reduce the overshoot in the system response, including, the time response and settling time. For yaw control (a motion around the z-axis), an occurrence of an overshoot in the system response is highly intolerable. Reducing the overshoot in the ROC trajectory is crucial since there are many challenging underwater natures and underwater vehicle control problems while studies on finding the solutions are still ongoing to find an improvement. Conventional Proportional-Integral-Derivative (PID) controller is not robust to be applied in the ROC due to the non-linear dynamic model of the ROC and underwater conditions. Besides that, by reducing the overshoot, the ROC mobility will be much more efficient and provided a reliable platform for underwater data mining. This study is focused to give an optimum performance of yaw control without overshoot in the system response and faster time response. This research begins by designing an underwater ROC as the research’s platform. Then, the designed ROC is simulated by using SolidWorks software obtain the analysis of structural integrity and hydrodynamic properties. System identification technique is conducted to obtain the empirical modelling design of the fabricated ROC which equipped with Inertial Measurement Unit (IMU) sensor. The fuzzy logic controller (FLC) is designed based on 5 by 5 rule matrix which has to deal with fuzzification, rule base, inference mechanism and defuzzification operations. A simplification of the FLC is proposed and the method is called Single Input Fuzzy Logic Controller (SIFLC). The simplification is achieved by applying the “signed distance method” where the SIFLC reduces the two-input FLC to a single input FLC. In other words, SIFLC is based on the signed distance method which eventually reduces the controller as single input-single output (SISO) controller. A PID controller is designed for the purpose of benchmarking with the FLC and SIFLC. SIFLC has the capability to adapt the non-linear underwater parameters (currents, waves and etc.). This research has discussed and compared the performance of PID, FLC and SIFLC. The algorithm is verified in MATLAB/Simulink software. Based on the results, SIFLC provides more robust and reliable control system. Based on the computation results, SIFLC reduces the percentage of overshoot (%OS) of the system and achieve 0.121%, while other controllers (PID and FLC) 4.4% and 1.7% respectively. Even that so, this does not mean that PID and FLC are not reliable but due to the presence of %OS

Design Process and Hydrodynamic Analysis of Underwater Remotely Operated Crawler

Underwater Remotely Operated Crawler (ROC) is a type of underwater Remotely Operated Vehicle (ROV) that able to operate underwater and even on land. The distinctive design of the ROC compared to other underwater vehicle is, ROC allows for underwater intervention by staying direct contact with the seabed. The common issues faced by all underwater vehicles are the drag that occurs when the vehicles move underwater. It is important to reduce the drag in order to increase the speed of the ROC with less power consumption. As such, the study of hydrodynamics to the ROC is essential so that the stability and maneuverability of the ROC can be guaranteed. SolidWorks software is used to design and analyses the ROC. The dimension of the ROC is 100-mm high, 449.60-mm long and 297.60 width. The body or chassis of the ROC is made of stainless steel. Based on the design and the capability of the ROC, it is estimated that the ROC can operate with less drag, withstand the underwater forces and stable to operate on the seabed

Small Scale Unmanned Underwater Remotely Operated Crawler (ROC)

This project is describes the development of underwater vehicle which is remotely operated crawler (ROC). The ROC is developed for the implementation of underwater surface floor and used as for rescuing application. This project is aim to reduce the risk the human life and to solve the disability of human to dive to the underwater for rescue and archeologist work in a longer period. Due to the underwater vehicle that can be operated in a larger depth and reducing the liability of the human life. Moreover, the main problem with this ROC application is to travelling under the uneven of the underwater floor and make sure it always have negative buoyant and a good stability to perform at uneven surface of underwater. Furthermore, the ROC need the overcome the obstacle of the underwater surface without any problem. Therefore, the design of ROC is based on four wheel mechanism to maneuver it at the uneven surface. Besides that, the ROC is tethered and control manually by using a joystick controller and the Peripheral Interface Controller (PIC) are used to control this ROC. This method is to fulfill the target of the project that are to develop and fabricate the ROC and to study the performance of the ROC in terms of controllability, stability and maneuverability. As a result, the movement of ROC is analyzing in order to gain the requirement of stability and the buoyancy in the water. Moreover, the development of the ROC can be tested in several experiments which includes overcome obstacle, controllability, and it performances to be operated on the surface floor of underwater. Hence, this project will gives the good impact and benefit related to the underwater industries and can be applied in the rescuing application in the future

Analysis of integrated sensor for unmanned underwater vehicle application

2552-2561This paper presents an integrated sensor system to be applied in underwater vehicles based on 5-DOF Inertial Measurement Unit (IMU) sensor, MPX pressure sensor, and temperature sensor. The main idea of the research is to improve the performance of the integrated sensor system by using the MATLAB/Simulink interfaced with MicroBox 2000/2000C for underwater vehicle applications. An integrated sensor or known as the smart sensor is a small component that designed to gather important data based on underwater applications.  These types of sensors combined and integrated with signal processing hardware in a single compact waterproof device. All sensors are placed in a hard casing made of steel with the dimensions of 0.10 m diameter, 0.85 m height and weight of 0.23 kg. The output of the sensors shows that; the offset error of accelerometer and gyroscopes are within 0.5 to 1.0 and 0.1 to 0.5, respectively. It is shown that the pressure occurs at 0.75s and the reading on voltage increased rapidly until 0.5V and maintained at 0.5V for 1 s. With minimum implementation cost and improved performances of the integrated sensors, this research benefits offshore and underwater industries especially for underwater vehicle

Analysis Of Integrated Sensor For Unmanned Underwater Vehicle Application

This paper presents an integrated sensor system to be applied in underwater vehicles based on 5-DOF Inertial Measurement Unit (IMU) sensor, MPX pressure sensor, and temperature sensor. The main idea of the research is to improve the performance of the integrated sensor system by using the MATLAB Simulink connected to MicroBox 2000/2000C for underwater vehicles applications. An integrated sensor or known as the smart sensor is a small component that designed to gather important data. These types of sensors combined or integrated with signal processing hardware in a single compact device. All sensors are placed in a hard casing made of steel with the dimensions of 0.10 m diameter, 0.85 m height and weight of 0.23 kg. The output of the sensors shows that; the offset error of accelerometer and gyroscopes are within 0.5 to 1.0 and 0.1 to 0.5 respectively. It is shown that the pressure occurs at 0.75s and the reading in volt increased rapidly until 0.5V and maintained at 0.5V for 1 s. With minimum implementation cost and improved performances of the integrated sensor, this research benefits offshore and underwater industries