I have found "Shell Ocean Discovery Xprize" as a wonderful compete. As a senior expert in the underwater robotics engineering, I understand the difficultness of the project. To have a successful mission underwater, it's really important to have a reliable Underwater thrusters.
Today I’m going to share +15 years of my experiences about underwater thruster and the parameters which turned them exceptional one. The parameters have been arranged from the most important to least important ones.
1- Reliability: Reliability is the most important parameter for whom that knows the value of the time. Logistic costs for industrial operations are among the highest one, and unreliable thrusters easily terminate the operations and increase the cost dramatically.
2- Redundancy: Every system is subjected to damage, even the most reliable and professional one. Here redundancy helps the systems to keep working in most critical conditions. Redundancy in sealing, motor controller PcB and etc reveals its value when some trouble comes through within critical operations.
3- Efficiency: Tethers always have the highest portion of drag force especially in high current waters. Thicker tether causes more drag which results demanding more energy and thicker tether. The key parameter is the thruster efficiency. More efficient thruster, The thinner tether the and lower drag force, It is an amazing positive loop which pushes the designer to select highest available thruster on the market.
4- Ease of maintenance: Some thrusters need to be carefully checked and some lengthy algorithm be done after each operation. Most users are unhappy with this sort of thrusters. A good thruster must need least of care and maintenance (sometimes up to years). in some professional one, the thruster itself remind the user the maintenance periods.
5- System friendliness: There are lots of parameters which makes a thruster to be system friendly or not. Electrical noise is one of them. Some thrusters emitted a considerable amount of electrical noises which interfere other electronics, especially the navigation system. Ease of changing procedure of the failed thruster is the other parameter of system friendliness. Most of the thrusters need the system central controllable electronics to be programmed and etc. It is very important that the thrusters be plug and play.
Fortunately today there are some well known valuable options on the market, to be selected by engineers and designers as the AUV / ROV thrusters. Among them, Lian Innovative has revealed the most advanced one which fitted mostly all of above parameters. Lots of options and configurations are available from them which make the best choice selection as easy as possible.