System and method of robot locomotion

1 . A robotic device for inspecting structures, comprising:

a body extending in a longitudinal direction of the robotic device, the body having a front end, a rear end, and opposing sides extending between the front end and the rear end, and a body length;

a plurality of legs arranged on each of the opposed sides of the body, each leg comprising one or more joints, wherein the plurality of legs is arranged as one or more pairs of legs, and wherein one leg of a pair of legs is arranged on an opposite side of the body widthways to the other; and

a plurality of carriages, each carriage connecting a leg to the body and being configured to allow each leg to translate in a longitudinal direction relative to the sides of the body, wherein any one of the plurality of carriages is configured to translate 60% or more of the body length of the robotic device, and

wherein each of the carriages is configured to move independently of each of the other carriages such that a leg separation may be varied, the leg separation being the distance between any two adjacent legs on one side of the body, and

wherein the carriage of the one leg of a pair legs is configured to move independently of the carriage of the leg on the other side of the body.

2 . The robotic device of claim 1 , wherein each leg comprises one or more rotational degrees of freedom.

3 . The robotic device of claim 1 wherein each of the legs comprises a first part of a hip joint where each leg connects to each respective carriage, and wherein the body further comprises a guide, each of the plurality carriages being connected to the guide such that the carriage is configured to translate along the side of the robotic device, guided through interaction with the guide, towards the front end or rear end of the body.

4 . The robotic device of claim 3 , wherein each carriage comprises a sliding interface configured to couple the carriage to the guide, and wherein the carriage further comprises an articulation configured to provide a second part of the hip joint and join the carriage via the hip joint to an upper limb segment of the leg.

5 . The robotic device of claim 3 , wherein the body comprises a left-hand guide associated with a left side of the body and a right-hand guide associated with a right side of the body, wherein each guide comprises a rail, which extends in the longitudinal direction along the body, the plurality of legs on a given side of the body being connected to the rail to guide the movement of each leg as the leg translates along a side of the body.

6 . The robotic device of claim 5 , wherein the rail or rails on each side of the body are linear or near linear.

7 . The robotic device of claim 5 , wherein the left side and the right side are flat sides and the guides are provided on and extend along the flat left and right sides of the body.

8 . The robotic device of claim 5 , wherein the left side and the right side are curved sides and the guides are provided on and extend along the curved left and right sides of the body.

9 . The robotic device of claim 4 , wherein each leg further comprises a lower limb segment, wherein the lower limb segment is connected to the upper limb segment by a lower articulation.

10 . The robotic device of claim 9 , wherein a foot is connected to the lower limb segment of the leg by an ankle joint allowing rotational movement of the foot relative to the lower limb segment and linear movement of the foot relative to the lower limb segment.

11 . The robotic device of claim 10 , further comprising a controller configured to control the position of the body relative to each foot when each foot is positioned on a surface.

12 . The robotic device of claim 1 , wherein the robotic device further comprises limit switches configured to prevent collisions between adjacent carriages and/or legs.

13 . The robotic device of claim 1 , wherein the robotic device comprises a hexapod and each leg is able to translate at a hip joint with respect to the body of the robotic device in the longitudinal direction of the body.

14 . The robotic device of claim 1 , wherein each leg comprises utilities for control and operation of the leg, wherein the utilities include power, pneumatics, and/or hydraulics.

15 . The robotic device of claim 14 , wherein cabling for the utilities is housed in one or more cavities within the leg.

16 . A method of locomotion for the robotic device as claimed in claim 1 , comprising:

raising and lowering legs from and to a surface in a stepwise motion to move the body of the robotic device with respect to a structure, wherein the method of locomotion further includes translating each leg in a longitudinal direction along a side of the body when each leg is in a raised position.

17 . A method of locomotion as claimed in claim 16 , comprising:

raising a first set of legs from the surface into an up position, the first set of legs comprising a left leg of a first pair of legs and a right leg of a second pair of legs, wherein the first pair of legs is adjacent to the second pair of legs;

translating the first set of legs in the longitudinal direction;

translating, with the first set of legs, the body in the longitudinal direction;

lowering the first set of legs into a down position on the surface;

raising a second set of legs from the surface into the up position, the second set of legs comprising a right leg of the first pair of legs and a left leg of the second pair of legs;

translating the second set of legs in the longitudinal direction;

translating, with the second set of legs, the body in the longitudinal direction;

lowering the second set of legs into the down position on the surface.

18 . The method of claim 17 , further comprising:

rotating at least one of the first or second sets of legs relative to the body.

19 . A method of locomotion as claimed in claim 16 , comprising:

raising a first pair of legs from the surface into an up position;

moving the first pair of legs in the longitudinal direction;

lowering the first pair of legs into a down position on the surface;

raising a second pair of legs from the surface into the up position, wherein the second pair of legs is adjacent to the first pair of legs;

moving the second pair of legs in the longitudinal direction;

lowering the second pair of legs into the down position on the surface;

moving the body in the longitudinal direction.

20 . The robotic device of claim 14 , wherein each leg comprises a suction generating device for generating suction in a suction cup and/or a power source.