Auto depth control for underwater remotely operated vehicles using a flexible ballast tank system

• Main Authors: Mohd Shahrieel , Mohd Aras, Shahrum Shah , Abdullah, Fadilah , Abdul Azis, Mohd Khairi , Mohd Zambri, Mohd Zambri , Md Basar
• Format: Article
• Language: English
• Published: UTEM 2015
• Subjects: TC Hydraulic engineering. Ocean engineering
• Online Access: http://eprints.utem.edu.my/id/eprint/14886/1/V07_N01_10%2857-64%29-JTEC.pdf; http://eprints.utem.edu.my/id/eprint/14886/

This paper describes the development of autodepth control using a flexible ballast tank system for underwater Remote Operated Vehicle (ROV) that is commonly used in underwater application, such as monitoring, surveying and researching activities. Since the ROV design must be able to submerge and emerge, buoyancy control is needed. However, it is difficult to get the ROV to maintain at a constant depth for it to perform a desired task using the thruster system. This is because the power consumptions and saturated at certain depths depend closely on the design of thruster for the ROV. Thus, the ROV needs to have an auto depth control to maintain their depth so that all activities such as collecting data, monitoring and surveying at a constant specific depth can be carried out with minimum power consumption. This research attempts to design an auto depth control using a flexible ballast tank system for the ROV equipped with a pressure sensor as a depth sensor. The flexible ballast tank system is based on the principle of the pump that adopts the inlet or outlet water inside the tank by controlling the polarity of the pump regulated by a relay that acts like a switch. The switch is used to control the flow of current and activate the coil when it is triggered. The pressure sensor from a model MPX4250GP has been used and it functions as the depth sensors that send signal to PIC to execute the function of relay for controlling the pump’s polarity. In dealing with the controlling part, PIC is used as the microcontroller interface to program the relay function. There are two major phases in developing the auto depth system for the flexible ballast tanks: the hardware and software designs that consist of mechanical design and programming. The ROV will be tested in a laboratory pool to get the data that will be analyzed. This ROV is proven to be able to control the desired depth of 1 meter by controlling the flow of water inside the flexible ballast tank with minimized power consumptions.