Underwater vehicle with front-rear distributed drive

1. An underwater vehicle, comprising:

a main body having a front end and a rear end, wherein the main body defines a longitudinal axis extending from the front end to the rear end of the main body;

a front-drive mechanism connected to the main body to provide a forward propelling force in a direction parallel to the longitudinal axis;

a rear-drive mechanism; and

a steering assembly fixed to the rear end and coupled to the rear-drive mechanism,

wherein:

the steering assembly is configured to rotate the rear-drive mechanism with respect to the longitudinal axis by a body angle for providing a lateral force on the main body; and

the front-drive mechanism comprises four front motors arranged symmetrically with respect to the longitudinal axis.

2. The underwater vehicle of claim 1 , wherein the front-drive mechanism comprises a plurality of front motors connected to a periphery of the main body.

3. The underwater vehicle of claim 2 , wherein the plurality of front motors are arranged symmetrically with respect to the longitudinal axis.

4. The underwater vehicle of claim 1 , wherein the steering assembly comprises a steering engine and a steering arm, wherein the steering arm is pivotable by the steering engine to rotate relative to the longitudinal axis by the body angle.

5. The underwater vehicle of claim 4 , wherein the steering engine is a servo motor, a stepper motor, or an electromechanical device, such that the body angle is accurately controlled.

6. The underwater vehicle of claim 4 , wherein the rear-drive mechanism is fixedly connected to the steering arm, thereby the rear-drive mechanism provides the lateral force derived according to a motion direction.

7. The underwater vehicle of claim 6 , wherein the rear-drive mechanism comprises one or more rear motors arranged to propel along a tail direction defined by the body angle.

8. The underwater vehicle of claim 7 , wherein the steering arm is attached to a cuspate fin structure, wherein the cuspate fin structure is a bionic fishtail for balancing and steering the one or more rear motors to propel along the tail direction.

9. The underwater vehicle of claim 6 , wherein the rear-drive mechanism comprises two rear motors arranged symmetrically with respect to the steering arm to propel along a tail direction defined by the body angle.

10. The underwater vehicle of claim 1 further comprising a processor configured to dynamically adjust the forward propelling force, the lateral force, and the body angle for performing a variety of linear motions and turning motions.

11. The underwater vehicle of claim 10 , wherein the processor is configured to adjust the forward propelling force, the lateral force, and the body angle based on a regularized stokeslet model as defined by:

v

i

(

x

)

=

1

8

⁢

π

⁢

μ

⁢

S

ij

ε

(

x

,

x

0

)

⁢

g

j

;



ϕ

ε

(

x

-

x

0

)

=

15

⁢

ε

4

8

⁢

π

⁡

(

r

2

+

ε

2

)

7

/

2

;

and

S

ij

ε

(

x

,

x

0

)

=

δ

ij

⁢

r

2

+

2

⁢

ε

2

(

r

2

+

ε

2

)

3

/

2

+

(

x

i

-

x

0

,

i

)

⁢

(

x

j

-

x

0

,

j

)

(

r

2

+

ε

2

)

3

/

2

,

wherein

:

v

i

(

x

)

⁢

is

⁢

velocity

;

μ

⁢

is

⁢

viscosity

⁢

of

⁢

the

⁢

fluid

;

S

ij

ε

(

x

,

x

0

)

⁢

is

⁢

a

⁢

regularized

⁢

Green

’

⁢

s

⁢

function

;

g

i

⁢

is

⁢

the

⁢

force

⁢

acting

⁢

on

⁢

the

⁢

segment

;

r

=



x

-

x

0



;

and

ε

⁢

is

⁢

a

⁢

regularized

⁢

parameter

.

12. The underwater vehicle of claim 1 , wherein the underwater vehicle is an autonomous underwater vehicle or a remotely operated vehicle.

13. The underwater vehicle of claim 1 , wherein the front end comprises a half-spherical shell, and the main body is a hollow cylinder.

14. A torpedo, comprising:

a main body having a front end and a rear end, wherein the main body defines a longitudinal axis extending from the front end to the rear end of the main body;

a processor housed within the main body;

a front-drive mechanism connected to the main body to provide a forward propelling force in a direction parallel to the longitudinal axis;

a rear-drive mechanism;

a steering assembly fixed to the rear end and coupled to the rear-drive mechanism; and

a navigation guidance system configured to communicate with and receive signals from object sensors, satellite communication terminals, or both the object sensors and the satellite communication terminals,

wherein:

the steering assembly is configured to rotate the rear-drive mechanism with respect to the longitudinal axis by a body angle for providing a lateral force on the main body;

the processor is configured to control the underwater vehicle in response to the navigation guidance system for performing linear motions and turning motions;

the front-drive mechanism comprises four front motors arranged symmetrically with respect to the longitudinal axis;

the steering assembly comprises a steering engine and a steering arm, wherein the steering arm is pivotable by the steering engine to rotate relative to the longitudinal axis by the body angle;

the rear-drive mechanism is fixedly connected to the steering arm, thereby the rear-drive mechanism provides the lateral force derived according to a motion direction; and

the rear-drive mechanism comprises two rear motors arranged symmetrically with respect to the steering arm to propel along a tail direction defined by the body angle.

15. An underwater vehicle, comprising:

a main body having a front end and a rear end, wherein the main body defines a longitudinal axis extending from the front end to the rear end of the main body;

a front-drive mechanism connected to the main body to provide a forward propelling force in a direction parallel to the longitudinal axis;

a rear-drive mechanism; and

a steering assembly fixed to the rear end and coupled to the rear-drive mechanism,

wherein:

the steering assembly is configured to rotate the rear-drive mechanism with respect to the longitudinal axis by a body angle for providing a lateral force on the main body; and

the front end comprises a half-spherical shell, and the main body is a hollow cylinder.

16. The underwater vehicle of claim 15 , wherein the front-drive mechanism comprises a plurality of front motors connected to a periphery of the main body.

17. The underwater vehicle of claim 16 , wherein the plurality of front motors are arranged symmetrically with respect to the longitudinal axis.

18. The underwater vehicle of claim 15 , wherein the steering assembly comprises a steering engine and a steering arm, wherein the steering arm is pivotable by the steering engine to rotate relative to the longitudinal axis by the body angle.

19. The underwater vehicle of claim 18 , wherein the rear-drive mechanism is fixedly connected to the steering arm, thereby the rear-drive mechanism provides the lateral force derived according to a motion direction; and wherein the rear-drive mechanism comprises two rear motors arranged symmetrically with respect to the steering arm to propel along a tail direction defined by the body angle.

20. The underwater vehicle of claim 15 further comprising a processor configured to dynamically adjust the forward propelling force, the lateral force, and the body angle for performing a variety of linear motions and turning motions, wherein the processor is configured to adjust the forward propelling force, the lateral force, and the body angle based on a regularized stokeslet model as defined by:

v

i

(

x

)

=

1

8

⁢

π

⁢

μ

⁢

S

ij

ε

(

x

,

x

0

)

⁢

g

j

;

ϕ

ε

(

x

-

x

0

)

=

1

⁢

5

⁢

ε

4

8

⁢

π

⁡

(

r

2

+

ε

2

)

7

/

2

;

and

S

ij

ε

(

x

,

x

0

)

=

δ

ij

⁢

r

2

+

2

⁢

ε

2

(

r

2

+

ε

2

)

3

/

2

+

(

x

i

-

x

0

,

i

)

⁢

(

x

j

-

x

0

,

j

)

(

r

2

+

ε

2

)

3

/

2

,

wherein:

v i (x) is velocity;

μ is viscosity of fluid;

S ij ε (x, x 0 ) is a regularized Green's function;

g i is a force acting on a segment;

r=∥x−x 0 ∥; and

ε is a regularized parameter.