Sub­marines and au­ton­o­mous UUVs

Work­ing in tan­dem and the way for­ward

Vayu Aerospace and Defence - - Vayu - Igor Vil­nit CEO of Ru­bin De­sign Bureau

Covert mine re­con­nais­sance has many ad­van­tages and Igor Vil­nit, CEO of Ru­bin De­sign Bureau ex­plains how sub­marines and UUVs would work in tan­dem and the way for­ward in the time to come.

Also : The Ar­row ATBM; Nammo shoul­der-launched mu­ni­tions; Ar­row in Apache’s quiver; Irkut’s ad­vanced train­ers; An Amer­i­can Air Show; Ex­er­cise Inio­chos; Frisian Flag 2018; EART 2018.

We live in the cre­ative phase of un­manned ve­hi­cles. It was not so long ago that the ro­bot R2-D2 could ex­ist only in the fan­tas­tic world of Star Wars. To­day, we use sim­i­lar ro­bots in ev­ery­day life. Not try­ing to com­pete with Star Wars scope, let us con­sider the problem of in­ter­ac­tion be­tween sub­marines and un­der­wa­ter ro­botic ve­hi­cles.

A tor­pedo with acous­tic homing can be considered the first au­ton­o­mous un­manned un­der­wa­ter ve­hi­cle. No less an interesting ex­am­ple was the Granit mis­sile de­ployed for the first time in the sub­ma­rine of Os­car- class. These mis­siles had not only an ad­vanced homing sys­tem but could in­ter­act with each other dur­ing the flight, ex­chang­ing data and co­or­di­nat­ing their ac­tions. This be­hav­iour can be considered one of the first ex­am­ples of in­ter­ac­tion among un­manned ve­hi­cles in the group, which is called swarm­ing to­day.

Of course, en­durance of tor­pe­does and mis­siles is mea­sured in min­utes, pay­load is lim­ited by the ex­plo­sive charge. In con­trast, mod­ern un­manned un­der­wa­ter ve­hi­cles (UUVs) can op­er­ate au­tonomously for scores of hours, move with high ac­cu­racy along com­pli­cated tra­jec­to­ries, carry var­i­ous types of pay­load and act ac­cord­ing to so­phis­ti­cated al­go­rithms. At the same time, as com­pared to ‘ clas­sic’ sub­marines, UUVs re­main small and in­ex­pen­sive.

Sub­ma­rine Hunters

From the un­der­wa­ter war­fare point of view, the most at­trac­tive mis­sion for the un­manned un­der­wa­ter ve­hi­cles is to search for and trail en­emy sub­marines. Ro­bots, un­like clas­sic sub­marines, can also use un­stealthy meth­ods for en­emy’s search (for ex­am­ple, ac­tive sonar pings). De­struc­tion of such a ve­hi­cle due to its small size and ma­noeu­vra­bil­ity is not only dif­fi­cult but also too ex­pen­sive.

How­ever, this is not a low hang­ing fruit. Creation of these ve­hi­cles is full of dif­fi­cul­ties – pro­vi­sion of nec­es­sary en­ergy re­serve and speed, ac­com­mo­da­tion of large an­ten­nas and pro­cess­ing of sig­nals re­ceived from them, trans­mis­sion of data on the de­tected tar­gets, de­vel­op­ment of sub­ma­rine track­ing al­go­rithms and oth­ers.

These prob­lems can be solved in dif­fer­ent ways. One should choose the right places for sub­ma­rine hunt­ing, use ve­hi­cles in swarms, in­clude the ve­hi­cles in net­work sys­tems of de­tec­tion and data trans­mis­sion. An­other op­tion is to cre­ate rather large ve­hi­cles of dozens of tonnes dis­place­ment that have a lot of en­ergy and so­phis­ti­cated de­tec­tion means. Such ve­hi­cles are al­ready be­ing devel­oped and tested.

Un­manned ae­rial ve­hi­cles UAVs can be used for above- wa­ter sur­veil­lance. As early as World War II, sub­marines that car­ried re­con­nais­sance air­craft were devel­oped, and Ger­man sub­mariners used sub­ma­rine-launched gy­ro­planes and kites for tar­get search. How­ever, all these air­craft were sur­face-launched and they

had to be re­cov­ered af­ter the mis­sion. Nowa­days, al­ready there is ex­pe­ri­ence in launch­ing ex­pend­able un­manned ve­hi­cles from un­der­wa­ter through a clas­sic tor­pedo tube. Us­ing these ve­hi­cles, sub­marines are ca­pa­ble of con­duct­ing re­con­nais­sance beyond the hori­zon and even over land and avail­abil­ity of channel for covert re­cep­tion of data from re­leased drones con­sid­er­ably ex­pands in­tel­li­gence ca­pa­bil­i­ties of the sub­ma­rine.

Tar­get De­coys

En­hance­ment of acous­tic sys­tems en­ables sim­u­la­tion of an acous­tic sig­na­ture of sub­ma­rine with ac­cu­racy suf­fi­cient to de­ceive air­craft and ship sonars and in fu­ture sta­tion­ary sys­tems as well. To­day, the range of of­fered de­coy ve­hi­cles is large – from com­pact sin­gle-shot Mk.39 of 10 kg weight to huge ve­hi­cle MASTT with dis­place­ment over 60 tonnes.

The sub­ma­rine is ca­pa­ble of launch­ing only small de­coys of lim­ited en­durance. How­ever, large de­coys can be de­liv­ered by other ways and move on their own to the ar­eas where they will in­ter­act with sub­marines.

At the end of last year, the Ru­bin De­sign Bureau pre­sented a con­cept de­sign of the Sur­ro­gat ro­botic com­plex to be used for naval ex­er­cises. This large sub­ma­rine im­i­ta­tor equipped with a lithium-ion bat­tery can op­er­ate up to 1516 hours. And dur­ing that pe­riod of time it will sim­u­late ma­noeu­vring of en­emy sub­marines in­clud­ing ma­noeu­vres at high speed.

Ap­pear­ance and evo­lu­tion of acous­tic de­coys has led to the de­vel­op­ment and com­pli­ca­tion of tor­pedo homing sys­tems be­cause to­day they should dif­fer­en­ti­ate be­tween ac­tual and false tar­gets. Bat­tle of the ro­bots – tor­pedo and de­coy– is al­ready tak­ing place un­der wa­ter!

Com­mu­ni­ca­tion and Nav­i­ga­tion

Com­mu­ni­ca­tion sys­tems for sub­marines must be ro­bust and high-speed, but first of all they must be dis­creet to pre­serve sub­ma­rine’s over­all stealth. Use of satel­lite com­mu­ni­ca­tion sys­tems has in­creased con­sid­er­ably the se­cu­rity of ra­dio channel it­self, how­ever has not solved the problem to­tally. To use the satel­lite com­mu­ni­ca­tion sys­tem, the boat should come to the periscope depth and raise cre­ates masts. This dis­closes and puts in a dis­ad­van­taged tac­ti­cal po­si­tion. Sim­i­lar prob­lems arise when it is nec­es­sary to use GPS.

One of the so­lu­tions al­low­ing the sub­ma­rine to main­tain a two- way com­mu­ni­ca­tion and re­ceive data from space nav­i­ga­tion sys­tems ‘keep­ing speed and depth’ is a ra­dio com­mu­ni­ca­tion sys­tem with buoy an­ten­nas, for ex­am­ple, Cal­isto and RTOF (re­cov­er­able teth­ered op­ti­cal fi­bre) sys­tems. These sys­tems give greater free­dom to act but the sub­ma­rine still re­mains teth­ered to the sur­face although with a looser leash.

A num­ber of prob­lems can be solved when the UUV is used as a gate­way be­tween the un­der­wa­ter and air en­vi­ron­ment. The abil­ity of such com­mu­ni­ca­tion ve­hi­cles to ma­noeu­vre on their own prac­ti­cally lifts all the con­straints of the sub­ma­rine.

More­over, the ve­hi­cle can be pre­pro­grammed to trans­mit the in­for­ma­tion only af­ter a cer­tain pe­riod of time or af­ter mov­ing to the spec­i­fied area. In the same way, the R2-D2 ro­bot de­liv­ered the mes­sage on the Death Star plans to the Rebels. Dur­ing this process, the ve­hi­cle is able to re­ceive and trans­mit data to the sub­ma­rine with the help of high-fre­quency un­der­wa­ter acous­tic or even laser channel, i. e. it is un­nec­es­sary to launch and re­cover UUV.

As­sess­ment of En­vi­ron­men­tal Pa­ram­e­ters

As the theatre of sub­ma­rine op­er­a­tions passes to coastal and shal­low zones, map­ping of bot­tom ter­rain be­comes more and more im­por­tant. In­for­ma­tion on ter­rain is nec­es­sary not only for safe ma­noeu­vring near the bot­tom but may also give tac­ti­cal ad­van­tages al­low­ing the sub­ma­rine to ap­pear in a place where it was not ex­pected.

Ship and air­craft sonar sys­tems are con­stantly be­ing im­proved, and this fac­tor re­quires more metic­u­lous ac­count for hy­dro­log­i­cal pa­ram­e­ters. Firstly, to fa­cil­i­tate func­tion­ing of own de­tec­tion sen­sors they will al­ready have pre­set in­for­ma­tion on the un­der­wa­ter en­vi­ron­ment and, se­condly, to evade de­tec­tion by en­emy sen­sors. New re­quire­ments ap­pear as well. Thus, for laser com­mu­ni­ca­tion the wa­ter trans­parency should be known. Such in­for­ma­tion can be col­lected with on­board sen­sors but it takes a lot of time that may not be avail­able un­der cer­tain cir­cum­stances. In­stead of this, UUVs can eval­u­ate hy­drol­ogy com­par­a­tively fast and safely. Such ve­hi­cles are be­ing devel­oped by In­dian uni­ver­si­ties.

Launch of these ve­hi­cles from sub­marines has also been im­ple­mented: they can be launched from lock-in/lock­out cham­ber in­stalled on the sub­ma­rine hatch. Launch of these UUVs from mis­sile con­tain­ers is also be­ing devel­oped.

Mine De­tec­tion

To­day, many types of mine coun­ter­mea­sures un­manned ve­hi­cles have been devel­oped and are be­ing man­u­fac­tured – from light man-por­ta­ble of less than 40 kg to rather large ones with weight up to one tonne. In­dian com­pa­nies also of­fer such ve­hi­cles. There are even larger ve­hi­cles, for ex­am­ple, UUV RMMV with weight about 6 tonnes, which is used within the AN/ WLD- 1 sys­tem on board the ships like US Navy LCS. Sin­gle-shot un­der­wa­ter ve­hi­cles are used for mine sweep­ing.

How­ever, all these ve­hi­cles are in­tended for em­ploy­ment from sur­face ships. Hence, they can be used only in own coastal waters or in the ar­eas con­trolled by one’s own navy.

Near the en­emy’s lit­toral, in hos­tile con­di­tions, covert in­tel­li­gence is re­quired. And covert­ness can be en­sured only when a ve­hi­cle is de­liv­ered by a sub­ma­rine. More­over, it is the sub­ma­rine that more of­ten comes to the area of fu­ture op­er­a­tions for ISR pur­poses and there­fore it needs reliable and up-to-date in­for­ma­tion on the mine threat. It is faster and safer to gather the in­for­ma­tion us­ing UUV than to sur­vey the area with sub­ma­rine on­board sen­sors. In ad­di­tion, au­ton­omy of UUV al­lows the sub­ma­rine to solve other tasks while the ve­hi­cles sur­vey the area in or­der to de­tect mines.

How­ever, even an UUV launch from the sub­ma­rine is a se­ri­ous chal­lenge and UUV re­cov­ery is man­i­foldly dif­fi­cult. Though the dif­fi­cul­ties are not in­sur­mount­able; Swedish sub­marines op­er­ate the UUV AUV-62MR. Since 2007, the US Navy sub­marines have been us­ing the AN/BLQ-11 sys­tem ear­lier known as LMRS (Long-term Mine Re­con­nais­sance Sys­tem).

The Ru­bin De­sign Bureau has also devel­oped tech­nol­ogy for em­ploy­ing au­ton­o­mous UUVs and re­motely op­er­ated ve­hi­cles from un­der­wa­ter mov­ing ob­jects. Of course, this method re­quires not only UUV with suit­able ca­pa­bil­i­ties but adap­ta­tion of the sub­ma­rine it­self and rel­e­vant train­ing of the crew. Ex­pe­ri­ence shows that the de­vel­op­ment of mine coun­ter­mea­sure com­plex com­pris­ing UUV and sub­ma­rine makes high de­mands on both time and bud­get and even af­ter all ef­forts it may not meet cus­tomer’s re­quire­ments. How­ever, covert mine re­con­nais­sance has so many ad­van­tages that leading navies con­tinue ac­tiv­i­ties in this di­rec­tion.

De­coy

En­vi­ron­men­tal data col­lec­tion

Mine hunt­ing

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