The present disclosure relates to a vehicle. In particular, the present disclosure relates to an autonomous vehicle such as an underwater autonomous vehicle.

BACKGROUND

Conventional autonomous underwater vehicles [AUVs] come in two types known as torpedo and flooded hull types, associated with different thruster configurations. The torpedo AUVs (See for instance L3HARR1S), use one thruster propellor for direction. These AUVs have a relatively complex design and limited manoeuvrability making them unsuitable for use in complex terrain as they are prone to entanglement. Flooded hull AUVs or over actuated AUVs, have multiple thrusters and are highly manoeuvrable, however they have poor hydrodynamics and can be easily entangled, see for instance, A. Amory and E. Maehle, "SEMBIO - a small energy-efficient swarm AUV," OCEANS 2016 MTS/IEEE Monterey, 2016, pp. 1-7, doi: 10.1109/OCEANS.2016.7761458. As they use many thrusters, they also tend to be larger in size and more likely to fail.

It is an object of the disclosure to address one or more of the above mentioned limitations.

SUMMARY

According to a first aspect of the disclosure, there is provided a vehicle comprising a body extending along a longitudinal axis; three propulsive devices arranged in a triangular fashion, wherein each propulsive device is aligned along a propulsion axis substantially parallel to the longitudinal axis; and a controller adapted to control the propulsive devices. The propulsion axis may correspond to an axis of rotation of a rotor of the propulsive device.

Optionally, two propulsive devices are located in an upper region of the body, and one propulsive device is located in a lower region of the body, or two propulsive devices are located in the lower region of the body, and one propulsive device is located in the upper region of the body. For instance the three propulsive devices may be a top right propulsive device, a top left propulsive device and a bottom propulsive device.

Optionally, the body comprises three elongated cavities, each elongated cavity being configures to receive one propulsive device. For instance the cavities may have a tubular profile.

Optionally, each elongated cavity extends along a cavity axis that is parallel to the longitudinal axis. For instance the propulsion axis of each propulsive device may be aligned with the cavity axis in which the propulsive device is located.

Optionally, the body has a substantially triangularly-shaped cross section in a plane perpendicular to the longitudinal axis.

Optionally, each cavity axis passes through a vertex of the substantially triangularly-shaped cross section.

Optionally, each propulsive device among the three propulsive devices comprises a rotatable set of blades. For instance, each propulsive device may have three blades.

Optionally, the three propulsive devices comprise a first propulsive device having a blade pitch arranged to provide forward thrust when rotating in a first rotational direction; a second propulsive device having a blade pitch arranged to provide forward thrust when rotating in a second rotational direction opposite to the first rotational rotation; and a third propulsive device having a blade pitch arranged to provide backward thrust when rotating in the second rotational direction or the first rotational rotation.

For instance the first rotational direction may be clockwise, and the second rotational direction may be counter clockwise. Alternatively the first rotational direction may be counter clockwise and the second rotational direction may be clockwise.

Optionally, the first propulsive device and the second propulsive device are located in the upper region of the body and wherein the third propulsive device is provided in the lower region of the body; or wherein the first propulsive device and the second propulsive device are located in the lower region of the body and wherein the third propulsive device is provided in the upper region of the body.

Optionally, the body comprises a first lateral surface, a second lateral surface, a top surface, a rear surface, and a front surface.

Optionally, the vehicle comprises a solar panel provided on the top surface.

Optionally, the vehicle comprises a vertical stabilizer coupled to the top surface.

Optionally, each propulsive device is adapted to provide thrust in both forward and backward direction.

Optionally, the controller is adapted to control an amount and a direction of thrust provided by each one of the three propulsive devices. For instance the controller may adjust the rotational speed of the blades (for example number of revolution per minute rpm) to control the amount of thrust, and the rotational direction (clockwise or anticlockwise rotation) of the blades. Optionally, the controller is configured to control at least one of a yaw, a pitch and a roll of the vehicle.

Optionally, controlling the yaw is performed independently from the horizontal and vertical speed of the vehicle.

Optionally, the vehicle has a centre of mass and a centre of buoyancy, wherein the centre of mass is below the centre of buoyancy.

Optionally, the body has a central body portion and three elongated members attachable to the central body portion. For instance, the elongated members may be attachable on the central body portion to form the three elongated cavities.

Optionally, the vehicle comprises at least one receiver and at least one transmitter. For example the vehicle may comprise a plurality of receivers and transmitters distributed on the surface of the body.

Optionally, the transmitter and the receiver are adapted to provide optical communication.

Optionally, wherein the vehicle is an underwater vehicle. For instance the vehicle may be an autonomous underwater vehicle.

Optionally, the vehicle is an aerial vehicle. For instance the vehicle may be an unmanned aerial vehicle.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure is described in further detail below by way of example and with reference to the accompanying drawings in which: Figure 1A is a profile view of an underwater vehicle according to the disclosure;

Figure IB is an underside profile view of the underwater vehicle of figure 1, without cover members;

Figure 1C is a profile view of the underwater vehicle of figure 1, without cover members and without thruster guards;

Figure 2A is a side view of the underwater vehicle of figure 1;

Figure 2B is a side view of the underwater vehicle of figure 1, without cover members;

Figure 2C is a side view of the underwater vehicle of figure 1, without cover members and without thruster guards;

Figure 3A is a rear view of the underwater vehicle of figure 1;

Figure 3B is a rear view of the underwater vehicle of figure 1, without cover members;

Figure 3C is a rear view of the underwater vehicle of figure 1, without cover members and without thruster guards;

Figure 4A is a front view of the underwater vehicle of figure 1;

Figure 4B is a front view of the underwater vehicle of figure 1, without cover members;

Figure 4C is a front view of the underwater vehicle of figure 1, without cover members and without thruster guards;

Figure 5 is an elevated perspective view of the underwater vehicle of figure 1.

DETAILED DESCRIPTION

Figure 1A is a profile view of an underwater vehicle according to the disclosure. The underwater vehicle 100 has an elongated body 110 extending along a longitudinal axis 105. The body 110 has a substantially triangularly-shaped cross section in a plane perpendicular to the longitudinal axis. Three elongated cavities 112, 114 and 116 are provided within the body 110. Each elongated cavity is configured to receive a propulsive device, such as a thruster or a propeller. Each propulsive device is aligned along a propulsion axis substantially parallel with the longitudinal axis 105.

The body 110 has a central body portion 111 and a three elongated members 122, 124, 126, also referred to as cover members, attachable to the central body portion 111. The central body portion 111 has three recesses provided at the vertices of the triangularly-shaped cross section and extending along the length of the body portion 111. The recesses are curved inwardly towards the centre of the body portion 111.

The three elongated members have a semi-circular shape in the form of a half pipe. When attached onto the central body portion 111, each recess and each elongated member form a cavity having a tubular profile. Each cavity extends along a cavity axis 135 that is parallel to the longitudinal axis 105. A propulsive device is provided in each cavity to move and direct the underwater vehicle. Each propulsive device is designed to provide both forwards and reverse thrust in varying amounts. A controller, such as a microcontroller, is provided to control the propulsive devices.

Optionally, a vertical stabilizer 190 may be fitted on a top surface of the body 110. This vertical stabiliser 190 provides roll stability. It may also be fitted with one or more antennas for communication purpose (iridium, radio, modem, Wi-Fi, GPS). The stabilizer 190 may also contain navigation and status lights. The vertical stabilizer is above water when the vehicle is on the surface. The body 110 provides a housing for holding the various components of the vehicles including the controller and a power source, among others. Additional components and functionalities which may be included in the vehicle are discussed below.

A communication module may be provided for communicating data, for instance to an external server. The communication module may include one or more of a GPS antenna, an RF modem antenna, a Wi-Fi antenna and an iridium antenna. The GPS antenna may be used for satellite communication and localization. The radio antenna may be used for communication of up to 20km. The Wi-Fi antenna may be used for communication within a few meters. The iridium antenna may be used for sending small bits of data for instance 200 bytes via satellite.

The underwater vehicle may also be equipped with a one or more cameras. In figure 1, four windows 171, 172, 173, 174 are provided on each side for use with a pair of stereo cameras. A front window 175 is provided for use with a front camera. A plurality of lighting panels 176a, 176b are located on the side and front panels of the vehicle for illuminating surrounded areas. The lighting panels may be implemented in different ways, for instance they may be include an array of light emitting diodes [LEDs].

Several receivers may be provided on the body. In this example four receivers are implemented: a front receiver 180 located on the front panel and two side receivers 182a, 182b located on the right and left side panels and a rear receiver located on the back panel of the vehicle. A pair of transmitters 185a, 185b are provided on the front panel. Additional transmitters may also be provided on the side and rear of the vehicle. The receivers and transmitters may be implemented in different fashions, for instance they may be optical receivers and optical transmitters. The receivers and transmitters may be used for communicating with other underwater vehicles.

The vehicle is also provided with one or more power sources. For instance the vehicle may be provided with a battery pack, a coil for wireless charging and a solar panel.

A printed circuit board (PCB) may be provided that include various electronic circuitry. For instance a microcontroller for controlling the propulsive devices, a controller for controlling cameras mounted on the vehicles, transmitter /receiver circuitry, etc...

Figure IB is an underside profile view of the vehicle of figure 1, without cover members. Figure IB shows the central body portion 111 and two propulsive devices 140 and 150. Each propulsive device is located at the rear of the body and nested into the recess of the central body portion 111. Each propulsive device has a guard formed of a front guard portion and a rear guard portion. For instance the propulsive device 140 has a rear guard portion 141 and a front guard portion 142. The guard has a tubular shape. Each propulsive device is aligned along a propulsion axis corresponding to the axis of rotation of the motor/blades. The propulsion axis (axis of rotation) is substantially parallel to the longitudinal axis 105. In this example the propulsive device 140 has propulsion axis that is aligned with the cavity axis 135. Similarly, the propulsive device 150 has propulsion axis that is aligned with the cavity axis 136. The propulsive device 160 (not shown) has propulsion axis that is aligned with the cavity axis 137.

Figure 1C is a profile view of the underwater vehicle of figure 1, without cover members and without thruster guards. Each propulsive device has a plurality of blades arranged around a rotor or rotating motor. The blades may also be referred to as rotatable blades. In this example the propulsive device 140 has a set of three blades arranged to rotate with respect to a rotation axis that is aligned with the cavity axis 135. The blades can rotate clockwise or anticlockwise for providing either forwards or backwards thrust.

Figure 2A is a side view of the underwater vehicle of figure 1. Figure 2B is a side view of the underwater vehicle of figure 1, without cover members. Figure 2C is a side view of the underwater vehicle of figure 1, without cover members and without thruster guards. Figure 2C shows the propulsive device 140 having blades 143a-c. Also shown are support members 144a-c. The support members are connected to the front guard portion 142 to provide support for the motor.

Figure 3A is a rear view of the underwater vehicle of figure 1. Figure 3B is a rear view of the underwater vehicle of figure 1, without cover members 122, 124 and 126. Figure 3C is a rear view of the underwater vehicle of figure 1, without cover members and without thruster guards. Figures 3A-C shows that two propulsive devices 140 and 160 are located in an upper region of the body 110, and one propulsive device 150 is located in a lower region of the body. The top left propulsive device 140 may be referred to as port propulsive device. The top right propulsive device 160 may be referred to as starboard propulsive device. The propulsive device 150 may be referred to as bottom propulsive device.

Figure 4A is a front view of the underwater vehicle of figure 1. Figure 4B is a front view of the underwater vehicle of figure 1, without cover members. Figure 4C is a front view of the underwater vehicle of figure 1, without cover members and without thruster guards. The longitudinal members 122, 124 and 126 provide an enclosure that protects the propulsive devices. This prevents the blades of the propulsive devices to get entangled with external objects or with parts of other vehicles. The longitudinal members 122, 124 and 126 also prevent direct access to the blades hence reducing the risk of potential injuries that may be caused by touching spinning blades.

Figure 5 is an elevated perspective view of the underwater vehicle of figure 1. A solar panel 170 is provided on the top surface of the body 110. The solar panel may be connected to a re-chargeable battery for powering various elements and circuitry of the underwater vehicle. Also represented are the longitudinal axis 105, the lateral axis 106 and the vertical axis 107.

The design of the vehicle described above with reference to figures 1 to 5, is compact and minimises both the type and the number of moving parts. The vehicle may be implemented to be relatively small, for instance less than a meter long. Compared with conventional AUVs, the vehicle of the disclosure is easier to assemble, cheaper to manufacture and simple to repair whilst still providing excellent hydrodynamics, robustness, and ergonomics.

In operation, the vehicle may operate autonomously, that is without external intervention. For instance the controller may control the propulsive devices to alter the direction of the vehicle as required based on specific parameters. The vehicle may also be operated to alter its pitch, that is the rotation (up and down motion] of the vehicle around a lateral axis 106 perpendicular to the longitudinal axis 105.

The vehicle may also be operated to move in the water column, up and down, without forward or backward motion. The propulsive devices may be designed with a specific angle of the blades, referred to as blade pitch. The blade pitch may be described as a ratio of forward distance per rotation. The blade pitch can be chosen so that for a same rotational direction (for instance clockwise), the device provides thrust in the forward direction or in the backward direction.

The propulsive devices are selected so that two propulsive devices provide forward thrust when rotating in opposite rotational directions (one clockwise and the other anti-clockwise). In the present example the top propulsive devices 140 and 160 are chosen so that one propulsive device for instance the top right propulsive device 140 provides forward thrust when rotating clockwise and the top left propulsive device 160 provides forward thrust when rotating counter clockwise. Note that the figures do not reflect a particular blade pitch. The bottom propulsive device 150 may be chosen with a blade pitch to provide backward thrust when rotating clockwise or with a blade pitch to provide backward thrust when rotating anticlockwise. The speed of rotation of the top propulsive devices 140 and 160 compared with the speed of rotation of the bottom propulsive device 150 may also be adjusted so that the pitch of the vehicle is maintained, and the vehicle only moved vertically.

Several features are provided to improve the stability of the vehicle. The body of the vehicle is designed to have a top half portion that is less dense than its the bottom half portion so that the centre of mass of the vehicle is sufficiently bellow the centre of buoyancy. As a result, any torque that may be applied by one or more of the propulsive devices results in negligible roll of the vehicle (rotation along the longitudinal axis 105). The vehicle is designed to have one stable orientation also referred to as point of equilibrium or steady state. If the vehicle experiences roll, pitch or yaw then the vehicle naturally returns to the same stable orientation. The stabilizer 190 also provides additional stabilising effect by damping the dynamic instabilities in the roll axis.

The controller may also be configured to perform thruster torque compensation. This is because as stated above two propulsive devices are selected with a different blade pitch, one for providing forward motion when operating clockwise and one for providing forward motion when operating counter clockwise. For instance, with reference to figure 3A, the propulsive device 160 may have a set of blades rotating in a clockwise direction, while the propulsive devices 140 and 150 have blades rotating in the counter clockwise direction. Consequently, when the vehicle is moving in a forward direction two of the torques, associated with the top propulsive devices 160, 140, are applied to the body 110 in opposite directions, hence compensating each other. The remaining torque of the third (bottom) propulsive device 150 is compensated by the offset centre of mass.

The vehicle may also be operated to perform sharp turns efficiently. The direction of rotation of the top left (port) propulsive device 140 and the top right (starboard) propulsive vice 160 may be chosen so that when a sharp turn is required, and the port and starboard propulsive devices are operated in opposite thrust directions then the torque applied from this opposed motion will result in the vehicle rolling such that it banks into a corner when moving forward.

The propulsive devices' controller uses the control and inputs from various instruments to attain the desired pitch, yaw, heading and vertical and horizontal speeds of the vehicle.

By varying a proportion of thrust in combination with the pitch of vehicle, the vehicle can independently control the yaw, and horizontal and vertical speed. As a result the vehicle is very manoeuvrable and capable of operating across rugged terrain while keeping the desired altitude and distance with respect to other vehicles or objects. This is different to other vehicles that either use more thrusters in other no co-linear configurations to obtain this independence or do not have this independence and require control surfaces and/or movable masses to alter course and orientation and hence cannot move directly to given positions without a series of manoeuvres, for instance by turning in circle.

The vehicle of the disclosure may be used for applications in the field of offshore wind industry (e.g. for cableways, monopile inspections); oil and gas (e.g. for post decommissioning monitoring, pipelines inspection); fisheries management (e.g. for habitat, scallop, lobster and clam surveys); marine end environmental science (e.g. for the monitoring of habitats); archaeology (e.g. for the searching and inspection of shipwrecks), among others. The images and data captured by the cameras fitted in the vehicle of the disclosure may be used to perform 3D reconstruction techniques using photogrammetry.

It will be appreciated that other implementations of the vehicle described above with reference to figures 1 to 5 could be envisaged. For instance the geometry of the vehicle and the body could be inverted so that instead of having two propulsive devices at the top and one at the bottom, two propulsive devices would be provided at the bottom and one at the top. The shape of the body itself may also be altered.

The arrangement of the propulsive devices described above in relation to an underwater vehicle, may be used for other types of vehicles for instance for an aerial vehicle or unmanned aerial vehicle UAV such as a drone. In this case the shape of the body as well as the features mounted on the vehicle may be adapted to make the vehicle lighter. Propulsive devices may also be selected with sufficient power to maintain the vehicle in the air.

A skilled person will therefore appreciate that variations of the disclosed arrangements are possible without departing from the disclosure. Accordingly, the above description of the specific embodiments is made by way of example only and not for the purposes of limitation. It will be clear to the skilled person that minor modifications may be made without significant changes to the operation described.