Associate Professor of Engineering Education, Department of Electronic and Computer Engineering, HKUST
In October, an aircraft crashed into the Java Sea, killing all 189 people on board.
Data retrieved from one of the plane's black boxes revealed the aircraft experienced problems with its airspeed indicators on its past four flights, although investigations are still ongoing to determine the cause of the crash.
Underwater missions such as these to retrieve black boxes are not as easy as people think.
The unpredictable nature of currents and extreme conditions sometimes hamper operations as it may be too dangerous to send in human divers.
But using underwater robots, or drones, as an alternative in the deep sea is not without its challenges.
The biggest challenge is the need to improve stability during the deployment of devices in the face of waves and currents; the density of water affects the floating power of devices under water, and there is also concern over water-proof capabilities and signal transfers.
In most situations, signal transfers are done by wire, as wireless transmissions cannot produce real-time footage and signals concurrently.
The wire's presence limits the depth and distance of the device's reach, as all signals grow weaker the further it travels.
Fortunately, a group of MIT researchers had recently addressed the problem by designing a novel system that allows underwater transmitters and airborne sensors to directly share data through transmitting and decoding sonar signals, which cause vibrations.
Despite technical difficulties that are pending to be solved completely, underwater devices, in particular robots, are still a much desired alternative to humans in hazardous or extreme circumstances.
For example, the cleanup of the Fukushima nuclear power plant after the 2011 tsunami will take years, or even decades, to complete, but the high radiation level in the innermost areas of the reactors mean they are "no man's land."
Without the help of underwater robots, the world would have known much less about what had happened and what needs to be done. Similarly, in deep-sea exploration, underwater robots have carried sensors and equipment to plunge into some of the deepest oceanic trenches on Earth where humans fear to tread and collected valuable data to let us know what it sounds or looks like down there.
In Hong Kong, underwater robots have the potential to be a game changer in many fields, as much of the underground drainage and sewers work, as well as beach maintenance, are still carried out by humans today.
In September, a lifeguard drowned while scuba diving to clear waste from a shark-prevention net off Tsuen Wan.
My hope is that it does not take any more tragedies for us to realize the value of underwater robot technology.
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