System for assisting in dragging operation on floating object

Abstract

A system and method for assisting in towing a floating object is disclosed. The floating object is provided with a wireless communication system and at least one position sensor for measuring the position of the floating object in at least three degrees of freedom. The main towing vessel is connected with the floating object through a towing cable. The main towing vessel comprises a winch, a DP system and a bidirectional wireless communication system. A tow assist system / module / controller may be integrated with the DP system. One or more auxiliary towing boats are connected to the floating object by towing cables. The one or more auxiliary towing boats are provided with a bidirectional wireless communication system. The tow assist system / module / controller calculates setpoints (forces and directions) for all tow vessels based on one or more input parameters from the floating object, one or more input parameters from each auxiliary tow vessel, and one or more input parameters from the main tow vessel.

Description

Technical Field

[0001] This invention relates to a towing assistance system for assisting in towing operations of floating objects. Background Technology

[0002] Traditional methods for towing floating objects from shipyards to work sites involve at least two support vessels and a main tugboat to help stabilize the object's lateral position. The operation is planned in advance according to the towing route. To control the deployment range and depth of the towing cables, the tension and length of the cables under specific conditions are usually calculated beforehand. The "tugboat supervisor" on the main tugboat monitors the overall situation and directs the support vessels during towing according to the plan. This role requires extensive experience.

[0003] Once the floating component arrives at its designated location, all vessels must coordinate to ensure it remains in place when the mooring cables are connected. This typically requires coordination with different installation vessels.

[0004] The floating object can be a vessel, semi-submersible drilling platform, floating aquaculture farm, offshore platform, jack-up platform, FPSO, or other floating objects requiring assistance during transport. The degree to which floating objects of different shapes and sizes are affected by wind and waves varies, which may increase the complexity of towing and installation operations. The floating object may also be equipped with actuators or propulsion systems.

[0005] Because there are a lot of towing operations in many different markets, there is a need for a system to help vessels to tow and install floating objects more efficiently and accurately without compromising the safety involved in these operations. Summary of the Invention

[0006] This invention provides a solution to at least some of the aforementioned problems. The invention is defined in the claims.

[0007] In one aspect, the present invention provides a system for assisting in the towing of floating objects. The system includes: - A floating object, comprising a wireless communication system and at least one position sensor for measuring the position of the floating object in at least three degrees of freedom; - The main towing vessel can be connected to a floating object via a towing cable. The main towing vessel includes a winch, a DP system, a two-way wireless communication system, and a towing assistance system / controller, wherein the towing assistance system is integrated with the DP system. - At least one auxiliary tugboat, which can be connected to the floating object via a tow cable, and which includes a two-way wireless communication system. -The towing assistance system is configured to calculate the setpoint of the DP system of the main towing vessel based on at least one first input parameter from a floating object, at least one second input parameter from at least one auxiliary towing vessel, and at least one third input parameter from the main towing vessel.

[0008] The towing auxiliary system can also be configured to calculate the setpoint of the main tugboat winch control system. The setpoint of the winch control system may include at least one of the towing cable tension and / or the towing cable length.

[0009] The setpoint of the calculated DP system may also include the length of the towing cable. The towing assistance system can be configured to calculate the setpoint of at least one auxiliary towing vessel.

[0010] The towing assistance system can be configured to calculate the setpoint of at least one thruster or actuator on the floating object.

[0011] At least one first input parameter from the floating object may include a force vector from any thruster or actuator on the floating object.

[0012] At least one first input parameter from the floating object may include the motion of the floating object, which includes at least one of swaying, rolling, and bowing.

[0013] At least one first input parameter from the floating object may include the motion of the floating object, which includes at least one of heave, roll, and pitch.

[0014] At least one first input parameter from the floating object may include the velocity and acceleration of the floating object in six degrees of freedom.

[0015] At least one second input parameter from at least one auxiliary tow vessel may include the propulsion of the at least one auxiliary tow vessel and the orientation of the at least one auxiliary tow vessel. At least one second input parameter from at least one auxiliary tow vessel may include the position of the at least one auxiliary tow vessel in at least three degrees of freedom.

[0016] At least one second input parameter from at least one auxiliary tugboat may include at least one of the following: - The motion of the auxiliary towing vessel includes at least one of heave, sway, pitch, roll, pitch and bow roll; - The tension of the towing cable between the auxiliary towing vessel and the floating wind turbine. - The length of the towing cable between the auxiliary towing vessel and the floating wind turbine.

[0017] At least one third input parameter from the main tugboat may include the thrust of the main tugboat's propellers and the orientation of the main tugboat. At least one third input parameter from the main tugboat may include the position of the main tugboat in at least three degrees of freedom.

[0018] At least one third input parameter from the main tugboat may include at least one of the following: -The motion of the main tugboat, including at least one of heave, sway, pitch, roll, pitch and bow roll; - Tension in the towing cable between the main tugboat and the floating object. - The catenary of the towing cable between the main tugboat and the floating object; - The length of the towing cable between the main tugboat and the floating object; - Output from the winch control system of the main tugboat.

[0019] The auxiliary towboat may also include a DP system. The auxiliary towboat may also include a winch with a winch control system. The floating object may also include at least one of a satellite navigation system, an inertial measurement unit, or an inertial navigation system. The inertial measurement unit is at least one of a motion reference unit (MRU) and a motion gyrocompass (MGC). The floating object includes differential GPS, motion sensors, and a gyrocompass. In adverse weather conditions such as wind and waves, INS can provide more control and higher accuracy.

[0020] Another aspect of the present invention provides a towing assistance system for assisting in towing operations of floating objects. The towing assistance system includes: - An interface for integrating a towing assistance system with a DP system so that the towing assistance system can receive at least one input parameter from the DP system and at least one input parameter from the winch control system; - An interface for receiving at least one first input parameter from a floating object; -The towing assistance system is adapted to calculate the setpoints of the main towing vessel and at least one auxiliary towing vessel based on at least one first input parameter from a floating object, at least one second input parameter from a winch control system of at least one auxiliary towing vessel, and at least one third input parameter from a DP system and a winch control system of the main towing vessel.

[0021] The towing auxiliary system can also be used to calculate the setpoint of the winch control system for a main towing vessel. The setpoint of the winch control system may include at least one of the tension of the towing cable and / or the length of the towing cable.

[0022] The setpoint of the main tractor may include the propulsion of at least one of the main tractor's thrusters and the main tractor's heading.

[0023] The setpoint of at least one auxiliary tugboat may include the propulsion of at least one thruster of the at least one auxiliary tugboat and the direction of the at least one auxiliary tugboat.

[0024] The setpoint of the calculated DP system may also include the length of the tow cable.

[0025] The setpoint of the calculated DP system can include the force vector of any thruster or actuator attached to the floating object.

[0026] At least one first input parameter from the floating object may include the position of the floating object in at least three degrees of freedom. At least one first input parameter from the floating object may include the motion of the floating object, which includes at least one of roll, pitch, and yaw. At least one first input parameter from the floating object may include the velocity and acceleration of the floating object in six degrees of freedom. At least one first input parameter from the floating object may include the motion of the floating object, which includes at least one of roll, pitch, and heave.

[0027] At least one second input parameter from at least one auxiliary tow vessel may include the propulsion force of the at least one auxiliary tow vessel and the orientation of the at least one auxiliary tow vessel. At least one second input parameter from the auxiliary tow vessel may include the position of the auxiliary tow vessel in at least three degrees of freedom. At least one second input parameter from the at least one auxiliary tow vessel may include the motion of the auxiliary tow vessel, the motion of which includes at least one of heeling, swaying, pitching, rolling, and heeling.

[0028] At least one second input parameter from at least one auxiliary tugboat may include at least one of the following: - The tension of the towing cable between the auxiliary towing vessel and the floating object; - The length of the towing cable between the auxiliary towing vessel and the floating object; At least one third input parameter from the main tugboat may include the propulsion force of the main tugboat's propeller and the orientation of the main tugboat. At least one third input parameter from the main tugboat may include the position of at least one auxiliary tugboat in at least three degrees of freedom. At least one third input parameter from the main tugboat may include the motion of the main tugboat, which includes at least one of sway, pitch, and bow roll.

[0029] At least one third input parameter from the main tugboat may include at least one of the following: - The motions of the main tugboat include at least one of heave, sway, pitch, roll, pitch and bow roll; - Tension in the towing cable between the main tugboat and the floating object. - The catenary of the towing cable between the main tugboat and the floating object; - The length of the towing cable between the main tugboat and the floating object; - Output from the winch control system of the main tugboat.

[0030] Another aspect of the present invention provides a main tugboat for assisting in towing operations of a floating object. The main tugboat can be connected to the floating object via a towing cable, and the main tugboat includes: -At least one thruster; -Wind and DP system; - Two-way wireless communication system; - Towing assistance system / controller, wherein the towing assistance system is integrated with the DP system; and -The towing assistance system is adapted to calculate the setpoints of the main towing vessel and at least one auxiliary towing vessel based on at least one input parameter to assist in towing operations of floating objects.

[0031] The towing auxiliary system can also be used to calculate the setpoint of the main tugboat winch control system. The calculation of the setpoint for the DP system can also include the calculation of the towing cable length.

[0032] At least one input parameter may include at least one first input parameter from the floating object, at least one second input parameter from at least one auxiliary towing vessel, and at least one third input parameter from the main towing vessel.

[0033] At least one first input parameter from the floating object may include at least one of the following: - The motion of a floating object, including at least one of heave, sway, pitch, roll, pitch and yaw. - The velocity and acceleration of a floating object in six degrees of freedom.

[0034] The towing assistance system can be integrated with the DP system and winch control system.

[0035] The calculation of the setpoint may also include the calculation of the propulsion force of at least one of the main tractor's thrusters, as well as the calculation of the main tractor's orientation.

[0036] At least one first input parameter from the floating object may include at least one of the following: - The position of a floating object in at least three degrees of freedom; - The motion of a floating object, including at least one of heave, sway, pitch, roll, pitch and yaw. - The velocity and acceleration of a floating object in six degrees of freedom.

[0037] At least one second input parameter from at least one auxiliary vessel may include at least one of the following: -The propulsion and heading of at least one auxiliary vessel; - The position of at least one auxiliary vessel, preferably in at least three degrees of freedom; -The motion of at least one auxiliary vessel, including at least one of heave, sway, pitch, roll, pitch and bow roll; - The tension of the towing cable between the auxiliary towing vessel and the floating object; - The length of the towing cable between the auxiliary towing vessel and the floating object; - The catenary of the towing cable between the tugboat and the floating object; - Output from the DP system of the auxiliary vessel.

[0038] At least one third input parameter from the main tugboat may include the propulsion force of the main tugboat's thrusters and the main tugboat's heading / track. At least one third input parameter from the main tugboat may include the main tugboat's position in at least three degrees of freedom.

[0039] At least one third input parameter from the main tugboat may include at least one of the following: -The motion of the main tugboat, including at least one of heave, sway, pitch, roll, pitch and bow roll; - Tension in the towing cable between the main tugboat and the floating object. - The catenary of the towing cable between the main tugboat and the floating object; - The length of the towing cable between the main tugboat and the floating object; - Output from the winch control system of the main tugboat.

[0040] On the other hand, the present invention provides a method for assisting in towing operations of floating objects. The method includes: - A floating object is towed by a main tugboat and at least one auxiliary tugboat, wherein the main tugboat and at least one auxiliary tugboat are connected to the floating object by towing cables, and the main tugboat is equipped with a towing assistance system. - Receive at least one first input parameter from at least one sensor on the floating object, wherein the at least one sensor includes a position sensor for measuring the position of the floating object in at least three degrees of freedom; -The towing assistance system is adapted to calculate the setpoints of the main towing vessel and at least one auxiliary towing vessel based on at least one first input parameter from a floating object, at least one second input parameter from at least one auxiliary towing vessel, and at least one third input parameter from the main towing vessel.

[0041] The method may further include calculating the setpoint of the main tugboat winch control system, wherein preferably, the setpoint of the winch control system includes at least one of the towing cable tension and the towing cable length.

[0042] The method may also include calculating the setpoint of the DP system of the main towing vessel, wherein the setpoint includes the length of the towing cable between the main towing vessel and the floating object.

[0043] The setpoint of the DP system of the main vessel includes the force of the main tugboat's propeller and the main tugboat's heading. The setpoint of the DP system of at least one auxiliary tugboat includes the propulsion force of the at least one auxiliary tugboat's propeller and the direction of the at least one auxiliary tugboat.

[0044] The position of a floating object in at least three degrees of freedom can be the global position.

[0045] The setpoints are independent. The system can calculate the setpoints of all vessels involved in the towing operation. A DP (Depth-Point) system is not required for towing operations. Vessels can be manually controlled to follow their setpoints. This allows for the use of different vessel types in towing operations. Different types of vessels can include, for example, tugboats, supply vessels, anchor handling vessels, etc. If a vessel is equipped with a DP system, it can perform towing operations in fully automatic mode based on the setpoints provided by the towing assistance system. A DP system is not required on auxiliary vessels.

[0046] Motion parameters can improve the accuracy, controllability, and safety of operations. Motion parameters can be provided by sensors on the floating object. They can also be provided to each vessel involved in the towing operation.

[0047] The DP system setpoint of the main tugboat can also include the length of the towing cable, thus providing greater flexibility, control, and safety.

[0048] The parameters of a floating object can include its motion. These motions can include swaying, rolling, and pitching.

[0049] Parameters from the floating object can also include its motion, which includes at least heave, roll, and pitch. By using measured data on pitch, roll, yaw, heave, roll, and pitch, operational accuracy can be improved. This can also improve the accuracy of the setpoints provided to the main tugboat, auxiliary tugboat, and winch control systems.

[0050] Furthermore, parameters from the floating object can also include its velocity and acceleration in six degrees of freedom. This will further improve operational accuracy and the precision of the setpoints provided to the main tugboat, auxiliary tugboat, and winch control systems.

[0051] Furthermore, parameters from the floating object can also include force vectors generated by any thrusters or actuators on the floating object. This provides more comprehensive information about all forces acting on the floating object, thereby improving the accuracy of towing assistance calculations in the towing assistance system.

[0052] Swell, roll, and bow are the most important parameters for a floating object. Roll and pitch provide more information, such as for correcting the position of a GPS antenna. Heave is the least important parameter because it does not affect the floating object's position on the sea surface. Heave information can provide additional information to the towing operator. More information can improve the accuracy and safety of floating object towing operations. The more parameters included in the towing assistance system's calculations, the more accurate the floating object's positioning will be. The operator can be a human, robot, humanoid robot, or computer. Operations can be performed autonomously, semi-autonomously, or manually. The position on the sea surface is represented by longitude and latitude.

[0053] GPS positioning can also provide information about longitude, latitude, and heading.

[0054] Dynamic positioning systems can use the axes of the ship's coordinate system to determine the ship's position and speed.

[0055] The towing assistance system calculates the setpoints of all towing vessels involved in towing a floating object. All towing vessels actively influence the movement of the floating object. Even if the towing vessels have lower accuracy in executing the setpoints—for example, if the towing vessels may require manual operation or longer execution time to execute the towing assistance system's setpoint commands—the towing operation can still proceed normally as long as the parameter measurements provided by the towing vessels can be obtained and transmitted to the towing assistance system. In its simplest form, a setpoint can be provided for a single towing vessel towing the floating object. However, when multiple towing vessels are towing a floating object in different directions, providing a setpoint to only a single towing vessel may result in less impact and lower accuracy.

[0056] Pitch, roll, and bow are the most important parameters because they provide information about the ship's position on the sea surface. Roll and pitch help correct for position. Heave may not need to be considered.

[0057] Winch tension is likely particularly important because the tension of the towing cable affects the ship's motion. While the length of the towing cable, its catenary, and its output length can provide some information to the operator, they are probably far less important than winch tension for controlling towing operations.

[0058] The floating object may also be equipped with actuators or propulsion devices, the force of which can be incorporated into the calculation of the towing assistance system, or even actively controlled by the system.

[0059] Standardizing towing methods for many different objects can improve safety and efficiency, and allow for more flexible use of towing capacity and towing equipment / towing vessels.

[0060] Drag-and-drop assistance features range from enhancing situational awareness, providing suggestions and control to fully automated and integrated drag-and-hook operations.

[0061] The uses of this function can be summarized in the following aspects: • Achieve reliable and efficient towing operations by raising awareness among tugboat captains and providing them with better support. Increase the likelihood of utilizing less experienced captains for similar operations globally.

[0062] • Improved on-site positioning and holding capabilities are enhanced by receiving guidance on optimal tugboat position and tension through a user-friendly interface.

[0063] • By controlling relative motion, peak / instantaneous loads are reduced, thereby improving control during hooking and tensioning processes.

[0064] Drag assistance can be broken down into multiple steps, ranging from improving situational awareness to automating processes. Attached Figure Description

[0065] The exemplary embodiments are illustrated with reference to the following figures, in which: Figure 1 An exemplary implementation of the overall concept is shown, in which two different towed vessels are attached to a floating object via tow cables. Wireless communication between the two different vessels and a sensor suite on the floating object is indicated by dashed lines.

[0066] Figure 2 An exemplary schematic diagram of towing-assisted context awareness is shown, outlining the towing situation of a towing operation on a main towing vessel for controlling a floating object, including historical locations, to illustrate the dynamic changes in the towing situation.

[0067] Figure 3 A schematic diagram of the catenary of the towing auxiliary towing cable of the towing auxiliary system on the main vessel is shown.

[0068] Figure 4 A schematic diagram showing the setpoint of each towing vessel in a towing situation is provided.

[0069] Figure 5This is an example view of the system topology of a towing auxiliary system with four towing vessels.

[0070] Figure 6 This is an exemplary schematic diagram of a floating aquaculture farm towing operation. The main towing vessel 1 is connected to the floating aquaculture farm 3 via towing cable 4. Another towing vessel 2 is also connected to the floating aquaculture farm via towing cable 4. The dashed line 5 represents communication between different entities in the system: the towing assistance system on the main towing vessel, the sensor suite on the floating aquaculture farm, and the auxiliary towing vessel 2. There is bidirectional communication between the main towing vessel 1 and the auxiliary towing vessel 2. Figure 6 The diagram also shows two-way communication between the floating aquaculture farm 3 and the main tugboat 1. The floating aquaculture farm may be equipped with actuators or propulsion systems.

[0071] Figure 7 This is an exemplary schematic diagram of a floating drilling platform towing operation. The main towing vessel 1 is connected to the floating drilling platform 3 via towing cable 4. Another towing vessel 2 is also connected to the floating drilling platform via towing cable 4. The dashed line 5 represents communication between different entities in the system: the towing assistance system on the main towing vessel, the sensor suite on the floating drilling platform, and the auxiliary towing vessel 2. There is bidirectional communication between the main towing vessel 1 and the auxiliary towing vessel 2. Figure 7 The diagram also illustrates two-way communication between the floating drilling platform 3 and the main tugboat 1. The floating drilling platform may be equipped with actuators or propulsion systems.

[0072] Figure 8 This is a schematic diagram illustrating the towing operation of another exemplary floating aquaculture farm. Figure 8 The floating aquaculture facility is hexagonal in shape. The main tugboat is connected to the floating aquaculture facility via tow cables. Two auxiliary tugboats are also connected to the floating aquaculture facility via tow cables. The towing direction is indicated by arrows.

[0073] Figure 9 This is an exemplary schematic diagram illustrating a towing operation of a vessel with two propellers 3. A main tugboat is connected to the vessel via towing cables. Three auxiliary tugboats are also connected to the vessel via towing cables. The towing direction is indicated by arrows.

[0074] Figure 10 This diagram illustrates another exemplary operation involving the towing of another floating object, such as an exemplary floating aquaculture farm. The main tugboat is connected to the floating object via towing cables. Two auxiliary tugboats are also connected to the floating object via towing cables. The towing direction is indicated by arrows. Detailed Implementation

[0075] Exemplary embodiments are described below with reference to the accompanying drawings. These exemplary embodiments are not intended to limit the scope of this disclosure.

[0076] Figure 1 The towing operation of a floating object is illustrated. The main towing vessel 1 is connected to the floating object 3 via towing cable 4. Another towing vessel 2 is also connected to the floating object via towing cable 4. The dashed line 5 represents the communication between different entities in the system: the towing assistance system installed on the main towing vessel, the sensor suite installed on the floating object, and the sensor suite on the auxiliary towing vessel.

[0077] Satellite navigation systems can be mounted on floating objects. Floating objects can also be equipped with inertial measurement units and / or inertial navigation systems.

[0078] An inertial measurement unit (IMU) can be a motion reference unit (MRU). An IMU can also be a motion gyrocompass (MGC). A floating object can have both an MRU and an MGC. Differential GPS, motion sensors, and gyrocompasses can be deployed on the floating object.

[0079] Figure 2 An example of a main view for towing-assisted situational awareness is shown, outlining the towing situation on the main vessel for controlling the towing operation of a floating object. The floating object is shown as a triangle in the figure, but it can also be other shapes. Figure 1 As shown, three tugboats are attached to a floating object at different corners of a triangle. The three tugboats can control towing by coordinating the pulling of the three corners. The towing cables of the three tugboats are connected to the stern. The towing cables can also be connected to the bow. Each tugboat is equipped with a winch. The towing cables are connected to the winches. The winches are controlled by a winch control system.

[0080] The accompanying figure illustrates an exemplary system topology for assisting in the towing of floating objects.

[0081] Boat Both the main tugboat and auxiliary tugboat can be equipped with a dynamic positioning (DP) system. A dynamic positioning (DP) system uses the vessel's own propeller and thrusters to automatically or semi-automatically control the vessel's position and heading relative to one or more positional reference points. A dynamic positioning (DP) system can maintain the vessel's position within a given range of parameters or enable the vessel to perform maneuvers that would be impossible without it. A dynamic positioning (DP) system can maneuver the vessel based on multiple input parameters. These input parameters can, for example, come from: - Sensors used to detect the ship's position, heading, and speed; - Sensors used to detect external factors such as wind, waves, and currents; and - Input from the user to perform tasks such as maintaining position or moving in a specific pattern.

[0082] User input can come from, for example, an external control center, other ships, the captain on board, or through interfaces of other systems. The captain can input mission data in various ways, including manually using a mouse, on-screen input, and voice input.

[0083] The control algorithm of a dynamic positioning (DP) system receives parameters from sensors and user input, and performs ship maneuvers by controlling the ship's propeller and thrusters, even when external forces change.

[0084] The DP system can control the ship based on at least one first input parameter, which may include at least one of the following: - The position of the floating object; -The ship's position; - The ship's course; -The ship's propulsion; - The motion of a floating object includes at least one of heave, sway, surge, roll, pitch and yaw; The motion of a ship includes at least one of heeling, swaying, pitching, rolling, pitching and bowing; Tension of the drag cable; The length of the towing cable; Catenary cable for towing; Output from the ship's winch control system.

[0085] The winch control system can be adapted to control the winch 6 on board based on at least one second input parameter, which may include at least one of the following: - The position of the floating object; -The ship's position; - The motion of a floating object, including at least one of heave, sway, pitch, roll, pitch and yaw. The motion of a ship includes at least one of heeling, swaying, pitching, rolling, pitching and bowing; The location of the tow cable; and Tension of the drag cable; Catenary cable for towing cables; Output from the ship's DP system.

[0086] The main tugboat and one or more auxiliary tugboats are connected to the floating object via a tow cable. The tugboats include onboard propellers and thrusters, which can be controlled manually, semi-automatically, or via a mission system or DP system. The tugboats are equipped with winches for retrieving and controlling the tow cable. The tugboats are also equipped with a two-way wireless communication system.

[0087] The main tugboat may include a DP (Drag and Drop) system. A towing assistance system / controller may be integrated with the DP system. As previously described, the towing assistance system calculates setpoints for the main tugboat and at least one auxiliary tugboat based on at least one input parameter to assist in towing operations of a floating object. The towing assistance system may calculate the setpoint for the winch control system used by the main tugboat. The calculation of the setpoint for the DP system may include the length of the towing cable. The at least one input parameter may include one or more parameters from the floating object, one or more parameters from at least one auxiliary tugboat, and one or more parameters from the main tugboat.

[0088] One or more parameters of a floating object may include the floating object's position in at least three degrees of freedom. One or more parameters of a floating object may include the floating object's motion, such as sway, pitch, yaw, and roll, pitch, and heave. Motion may also include the floating object's velocity and acceleration in six degrees of freedom.

[0089] The towing assistance system can be integrated with the DP system and winch control system. The DP system calculates the setpoint of the main tugboat, including the thrust of at least one of the main tugboat's thrusters and the main tugboat's heading.

[0090] One or more parameters from one or more auxiliary vessels may include the propulsion and heading of at least one auxiliary vessel. One or more parameters from one or more auxiliary vessels may also include the position of at least one auxiliary vessel, preferably its position in at least three degrees of freedom.

[0091] One or more parameters from one or more auxiliary vessels may also include at least one of the following: the motion of at least one auxiliary vessel, including at least one of heave, sway, pitch, roll, pitch and bow roll; - The tension of the towing cable between the auxiliary towing vessel and the floating object; - The length of the towing cable between the auxiliary towing vessel and the floating object; - The catenary of the towing cable between the tugboat and the floating object; - Output from the DP system of the auxiliary vessel.

[0092] One or more parameters from the main tugboat include the propulsion force of the main tugboat's propellers and the main tugboat's heading / progression. One or more parameters from the main tugboat may also include the main tugboat's position in at least three degrees of freedom.

[0093] One or more parameters from the main tugboat may include at least one of the following: -The motion of the main tugboat, including at least one of heave, sway, pitch, roll, pitch and bow roll; - Tension in the towing cable between the main tugboat and the floating object. - The catenary of the towing cable between the main tugboat and the floating object. - The length of the towing cable between the main tugboat and the floating object; - Output from the winch control system of the main tugboat.

[0094] The towing assistance system calculates the setpoints for all vessels involved in the towing operation. These setpoints from the towing assistance system are independent. A DP (Depth-Point) system is not required to perform the operation. Neither the main towing vessel nor one or more auxiliary towing vessels may need to be equipped with a DP system. Vessels can be manually controlled to follow the setpoints calculated by the towing assistance system. The main towing vessel may be equipped with a DP system, but one or more auxiliary towing vessels may not.

[0095] This allows for the use of different types of vessels in towing operations. These different types of vessels can include, for example, tugboats, supply vessels, and anchor handling vessels. If the main towing vessel and one or more auxiliary towing vessels are equipped with a DP system, the operation can proceed in fully automatic mode based on the setpoints provided by the auxiliary towing system.

[0096] Sensor kit like Figure 1 As shown, a minimal standalone sensor kit can be placed on floating components and support tugboats to wirelessly retrieve the required status data.

[0097] The following describes the floating object instrument kit in detail. This instrument kit can also be mounted on an auxiliary tugboat. The instrument kit can be mounted on the floating object in a compact unit configuration. The instrument kit can be detached from the floating object. The instrument kit may include: a differential GPS for measuring the floating object's position; motion sensors and a gyrocompass for measuring roll, pitch, heave, heading, and velocity and acceleration in six degrees of freedom; a marine broadband radio for wireless transmission (including two-way transmission) with the main tugboat and, possibly, the auxiliary tugboat; and a battery or conventional power supply for powering the instrument kit components.

[0098] The following example illustrates an instrument kit installed on a floating object.

[0099] The floating object may be equipped with an inertial navigation system (INS). The INS may include at least one of a satellite navigation system (such as a Global Navigation Satellite System (GNSS) or Global Positioning System (GPS)) and an inertial measurement unit (MRU or MGC) to measure the position and motion of the floating object. The satellite navigation system may be, for example, GNSS, GPS, GLOAASS, BeiDou, Galileo, QZSS, IRNASS, or NavIC. The INS may be attached to a second pulley / guide device near the tow cable after it leaves the floating object. This allows for monitoring of the floating object's motion, i.e., heave, sway, pitch, roll, trim, and bow. The floating object may also be equipped with a communication system (transceiver) for transmitting signals from floating instruments on the floating object to the installation vessel; these signals may be, for example, signals from the INS, sensors, and cameras. This communication system may be, for example, a marine broadband radio (MBR), or other wireless communication systems. Instruments on the floating object may be pre-installed. The devices on the floating components can be detachable.

[0100] The first sensor used to measure the distance between the floating object and the towed vessel can be mounted on the floating object and / or the towed vessel. The first sensor is typically a distance sensor. The distance sensor can be an optical sensor. The optical sensor can be a laser sensor or an infrared sensor. Depending on the system and system requirements, other distance sensors, such as radar or ultrasonic sensors, may also be used.

[0101] The relative motion between the main towing vessel and the floating object can also be estimated indirectly using data from at least two sensors, with at least one sensor mounted on the main towing vessel and at least one sensor mounted on the floating wind turbine platform. The at least two sensors can be absolute position sensors.

[0102] The floating object has a wireless communication system. The floating object is equipped with at least one position sensor for measuring the position of the floating object in at least three degrees of freedom.

[0103] The system may be equipped with at least one inertial navigation system (INS), which may be a satellite navigation system or an inertial measurement unit. The inertial measurement unit may be at least one of a motion reference unit (MRU) or a motion gyrocompass (MGC).

[0104] System Topology Figure 5An example of a towing device comprising four tugboats and the different systems involved is shown. In this example, a square floating object 1 is equipped with a sensor kit 9. All tugboats are connected to the floating object via their respective towing cables 4.

[0105] The main tugboat 2 may be equipped with a dynamic positioning system (DP) 6 and a winch 7. The main tugboat also has a towing auxiliary system (not shown). The winch is equipped with a winch control system. The winch control system is located on the main tugboat. The winch control system is connected to the DP control system to provide winch parameters to the DP control system, and the DP control system controls the winch. The DP system can be integrated with the winch control system. This integration provides operators of the integrated DP and winch control systems with a better operational overview.

[0106] The auxiliary tugboat 3 can have the same onboard components as the main tugboat. Figure 5 In the exemplary embodiment shown, the auxiliary tugboat is equipped with a towing assistance subsystem 8. This towing assistance subsystem is a subsystem of the towing assistance system 5. The towing assistance subsystem wirelessly communicates with the towing assistance system. This communication can be bidirectional. The towing assistance subsystem can receive setpoints from the towing assistance system on the main tugboat. The towing assistance subsystem can also be integrated with a DP (DP system) on the auxiliary tugboat. In some embodiments, the towing assistance subsystem on the auxiliary tugboat can also enable the auxiliary tugboat to receive information from a floating object. The towing assistance subsystem may also not be integrated with the DP system. When the towing assistance subsystem is not integrated with the DP system, the setpoints from the auxiliary tugboat system can be displayed on a monitor on the auxiliary tugboat. The operator of the auxiliary tugboat can use these setpoints to manually operate the auxiliary tugboat.

[0107] The dynamic positioning system (DP) on the main tugboat 1 can also be equipped with special enhanced mission equipment functions to control the main tugboat based on sensor system inputs on the floating object 1 during towing operations. The dynamic positioning system on the main tugboat can have a communication module to communicate with and control the winch control system. As a safety precaution in case of system failure, both the DP system and the winch control system can be equipped with manual control devices for operation by personnel on the main tugboat.

[0108] The floating object instrument, the main towing vessel’s winch (PIW) system and dynamic positioning (DP) system, and one or more auxiliary towing vessels that may be equipped with DP systems in some embodiments, work together to complete the floating object towing operation. Figure 5This illustrates the integrated concept between the floating object instrumentation suite, winch, and dynamic positioning system. The floating object instrument 9 measures the position and motion (heave, sway, pitch, roll, pitch, bow) of the floating object. These position and motion parameters are transmitted to the main tugboat. The dynamic positioning system controls the main tugboat based on multiple parameters, including the position of the main tugboat and the position and motion parameters from the floating object instrumentation, and compensates for the relative motion between the floating object and the main tugboat, thereby enabling controlled towing operations.

[0109] Integrating the winch control system with the main tugboat's DP system, and in some embodiments, with the DP system of the auxiliary tugboats if one or more auxiliary tugboats are equipped with DP systems, can perform coordinated ship positioning and winch pay-out / pay-in operations, and can also improve overall safety in the event of a ship DP accident or winch failure.

[0110] The ship processing unit on the main towing vessel can receive real-time position information from the floating object, calculate its relative position, velocity, and orientation, and output this data to the DP and winch control systems of the main towing vessel; and in some embodiments, if one or more auxiliary towing vessels are equipped with DP systems, this data can also be output to the DP systems of the auxiliary towing vessels. A remote motion system is provided on the floating object. This remote motion system may include an inertial measurement unit, a processing unit, and a battery. The remote motion system and the ship processing unit can communicate via a marine broadband radio (MBR) data link. Further details of these systems will be described later.

[0111] If the vessel (the main towing vessel, and in some embodiments, auxiliary towing vessels equipped with a DP system) is equipped with a dynamic positioning (DP) system, motion in 2×6 degrees of freedom (DOF) is measured and compensated for by synchronizing the DP control system and the winch control system. During operations where the vessel (the main towing vessel, and in some embodiments, one or more auxiliary towing vessels also equipped with a DP system) is attached to a floating object, the DP control system and the winch control system operate synchronously to maintain a safety margin. Synchronization of the DP control system and the winch control system may involve at least one of the following: the position of the floating object (e.g., measured by sensors on the floating object), the vessel position provided by the dynamic positioning system, the towing cable position provided by the winch / winch control system, and the operating status of the DP system and the winch / winch control system. The DP control system and the winch control system work together and are aware of each other's operating status based on the aforementioned input parameters. Each of the DP control system and the winch control system is also aware of the status of the other's system. The status can be a fault / error condition or whether the system is operating normally. In the event of a malfunction / error, this can be used to improve system safety. If either the DP control system or the winch control system malfunctions / errors during operation, meaning it cannot maintain the precise position of the vessel and towline, the remaining operational control systems (DP or winch control system) will move the vessel to a safer position. For example, the towline might be adjusted to a safe position, the operation might be reversed, or the operation might be aborted.

[0112] The floating object has a wireless communication system and one or more position sensors for measuring its position in at least three degrees of freedom. The main tugboat has a winch and is connected to the floating object via a towing cable. The main tugboat has a DP system. The main tugboat is equipped with a two-way wireless communication system for communicating with one or more auxiliary tugboats and receiving information from the floating object. When the towing assistance system is not mounted on the main tugboat, the main tugboat can also receive setpoints from the towing assistance system. The main tugboat can also send information to the towing assistance system. The towing assistance system can be mounted on other vessels or at remote locations, such as ashore. The towing assistance system / controller can be integrated with the DP system on the main tugboat. One or more auxiliary tugboats are connected to the floating object via towing cables. One or more auxiliary tugboats are also equipped with a two-way wireless communication system for communicating with the main tugboat and one or more other auxiliary tugboats. The two-way wireless communication system can also communicate with the towing assistance system. The auxiliary tugboats can receive setpoints from the towing assistance system via the wireless communication system. The auxiliary towing vessel can also send information to the towing assistance system via a wireless communication system.

[0113] The towing assistance system calculates the setpoint of the DP system of the main towing vessel based on at least one first input parameter from the floating object, at least one second input parameter from at least one auxiliary towing vessel, and at least one third input parameter from the main towing vessel.

[0114] The auxiliary tugboat may also include a DP system. The auxiliary tugboat is also equipped with a winch and a winch control system.

[0115] The towing assistance system will be described in detail below.

[0116] Towing Assist System The towing assistance system can be a computer mounted on the main towing vessel. To control the position and velocity of the undriven floating object, the towing assistance system uses a mathematical model to estimate the floating object's response under the actuation of the main towing vessel and an auxiliary vessel connected to the floating structure via towing cables. This model estimates the motion of the floating component based on sensor measurements and feedback from actuators on the main towing vessel and the auxiliary vessel. Actuators include propellers and thrusters. Furthermore, the mathematical model also considers the dynamic characteristics of the towing cables and the effect of wind on the floating object.

[0117] Configuration of the mathematical model: - The mass and drag characteristics of floating objects; - The geometry of the floating object, and the connection points of the towing cables on the floating object in relation to the towing cables from the main ship and auxiliary ships. - Wind zones of floating objects in all directions; - Characteristics of the towing cable (tension, length, catenary); - The size and characteristics of any actuator or propulsion unit attached to a floating object.

[0118] The model's input is: - The desired position, heading, and speed of the towed component; - Measurement data of the floating component provided by sensors in the instrument kit mounted on the floating component; - Wind speed measurement (received from the DP system on the main towing vessel); - Feedback from the actuators (received from all the DP systems on board and from the floating components themselves).

[0119] The model output is: - The force vector required for all vessels involved in the towing operation, including both the main towing vessel and the auxiliary towing vessel.

[0120] Secondary towing assist system The secondary towing assistance system is an interface unit installed on a remote vessel and connected to the primary towing assistance system via a wireless link. It receives setpoints from the primary towing assistance system and transmits feedback information from sensors on the secondary towing vessel to the primary towing assistance system.

[0121] In implementations where the auxiliary vessel cannot be automatically controlled, an additional screen can be installed on the auxiliary vessel. In this case, the setpoint calculated by the main towing auxiliary system can be displayed to the operator of the auxiliary vessel, allowing the operator to manually control the auxiliary vessel during towing operations.

[0122] By utilizing data from the winches on the main and auxiliary tugboats, along with a catenary model of the cables, the catenary lines of different towing cables can be visualized. This can be displayed as an xy-plot on the main tugboat and one or more auxiliary tugboats, such as... Figure 3 As shown, tow cable 1 can be compared with the current water depth 3 and waterline 2.

[0123] The above text is aimed at Figure 5 The example in the text illustrates that the drag assist subsystem can be a secondary drag assist system.

[0124] Consultation and Control The next step is to expand the functionality of the floating component model to calculate the forces required to control the floating component. The main tugboat and support tugboats (auxiliary tugboats) act as actuators for the passive floating component via tow cables. Based on the ideal position of the floating component, the optimal setpoint for each tugboat is calculated, including angles and total thrust. Angles are force angles. The setpoint for the angles is a vector containing both force and angle. By continuously calculating the setpoints and monitoring feedback, the towing assistance system can dynamically position the main tugboat, and possibly one or more auxiliary tugboats, along the desired path and control the towing speed.

[0125] Furthermore, the required cable tension, length, and catenary can be monitored and adjusted throughout the mathematical model, for example, to cope with narrow passages or shallow water areas.

[0126] The final part is how to apply the setpoint from the central towing assistance system to all connected vessels, which is typically installed on the main (primary) towing vessel.

[0127] Depending on the capabilities of the auxiliary vessel, the setpoint can be presented to the local captain or directly integrated into the control systems of each vessel. The following will describe three different integration levels.

[0128] Figure 4An example view of the auxiliary vessel's setpoint is shown. The figure shows the actual towing direction 1 and the deviation from the desired towing direction 3 calculated by the towing assistance system. The figure also shows the actual towing force 3 and the deviation from the desired towing force 4 calculated by the towing assistance system.

[0129] Assign the towing assist system setpoint to the towboat. The first level of integrated control displays one or more parameters of interest to the tugboat dispatcher, such as the optimal position, course, thrust, and / or towline length of the main and auxiliary tugboats. The towing assistance module / system calculates parameters such as the position, course, thrust, and / or towline length of the supporting tugboats and transmits this information manually via traditional channels. This means that no additional equipment is required on the tugboat besides the sensor suite used for situational awareness on the floating object.

[0130] The second level shifts the advisory service to the support tugboat. By installing a complete advisory kit with wireless communication capabilities into the tugboat's towing assistance system, the tugboat operator can directly see the recommended position. This improves the tugboat's responsiveness and enhances the accuracy of floating component positioning. The advisory kit may include a screen displaying the optimal vessel position, heading, thrust, and winch cable deployment. Data is received wirelessly from the main tugboat, for example, using an MBR.

[0131] The above text is aimed at Figure 5 The drag-assistance subsystem illustrated in the example may be a consulting suite in some implementations.

[0132] The complete integration of the towing assistance system with the tugboat's propulsion system means that the recommended setpoint can be set directly without human intervention. At this level, the tugboat needs to be equipped with a DP system or propulsion control system capable of receiving and applying direct thruster setpoints.

[0133] This level of integration opens the door to unmanned tugboat operations.

[0134] A towing assistance system is used to assist in towing operations of a floating object. The towing assistance system has an interface for integration with a dynamic control (DP) system. This interface enables the towing assistance system to receive at least one input parameter from the DP system and at least one input parameter from the winch control system. The interface also receives at least one first input parameter from the floating object. The towing assistance system calculates a setpoint for the towing vessels involved in the towing operation of the floating object. The towing vessels include a main towing vessel and at least one auxiliary towing vessel. The setpoint calculation is based on one or more parameters from the floating object, one or more input parameters from one or more winch control systems on the auxiliary towing vessels, and one or more input parameters from the DP system and winch control system on the main towing vessel.

[0135] The towing auxiliary system can calculate the setpoint of the winch control system of the main towing vessel. The setpoint of the winch control system can include the tension and / or length of the towing cable. Calculation of the setpoint for the DP system of the main towing vessel can include the length of the towing cable between the main towing vessel and the floating object. The towing auxiliary system can also calculate the setpoints of one or more auxiliary towing vessels.

[0136] At least one first input parameter from the floating object can include the position of the auxiliary towing vessel in at least three degrees of freedom. The input parameters can also include one or more motion parameters of the floating object. These motions can include pitch, roll, and yaw. Providing motion information from the floating object also includes heave, roll, and pitch, which can further improve the accuracy of commands (e.g., setpoints) provided by the towing assistance module to the main towing vessel and one or more auxiliary vessels participating in the floating object towing operation. Parameters from the floating object can also include the floating object's velocity and acceleration in six degrees of freedom. This will further improve the operational accuracy of the towing assistance system and the accuracy of calculated commands. Increased accuracy can improve the safety of towing operations.

[0137] At least one second input parameter from at least one auxiliary towboat includes the propulsion force of the at least one auxiliary towboat and the orientation of the at least one auxiliary towboat. Furthermore, this parameter may also include the position of the at least one auxiliary towboat in at least three degrees of freedom. The input parameter from the at least one auxiliary towboat may also include at least one of the following: - The motion of the auxiliary towing vessel includes at least one of heave, sway, pitch, roll, pitch and bow roll; - The tension of the towing cable between the auxiliary towing vessel and the floating object; - The length of the towing cable between the auxiliary towing vessel and the floating object.

[0138] The propulsion force of the main tractor and the orientation of the main tractor are provided to the towing auxiliary system as at least one third input parameter from the main tractor. Additionally, parameters relating to the position of the main tractor in three degrees of freedom can also be provided.

[0139] At least one third input parameter from the main tugboat may also include at least one of the following: -The motion of the main tugboat, including at least one of heave, sway, pitch, roll, pitch and bow roll; - Tension in the towing cable between the main tugboat and the floating object. - The catenary of the towing cable between the main tugboat and the floating object; - The length of the towing cable between the main tugboat and the floating object; - Output from the winch control system of the main tugboat.

[0140] In some implementations, the floating object may be without actuators or propulsion.

[0141] In other embodiments, the floating object may be equipped with actuators or propellers. The actuators or propellers of the floating object may or may not be used for towing operations.

[0142] Floating objects can come in a variety of shapes and sizes, and their exposure to wind and waves can vary, which can increase the complexity of towing and installation operations.

[0143] In an exemplary method, a floating object is towed by a main tugboat and at least one auxiliary tugboat, wherein the main tugboat and the at least one auxiliary tugboat are connected to the floating object via towing cables. The main tugboat is equipped with a towing assistance system. At least one first input parameter from at least one sensor on the floating object is received. The at least one sensor may include a position sensor for measuring the position of the floating object in at least three degrees of freedom. The towing assistance system calculates a setpoint for the main tugboat and the at least one auxiliary tugboat based on at least one first input parameter from the floating object, at least one second input parameter from the at least one auxiliary tugboat, and at least one third input parameter from the main tugboat.

[0144] The towing auxiliary system can also calculate the setpoint of the winch control system of the main tugboat. The setpoint of the winch control system can be the tension and / or length of the towing cable.

[0145] The calculation of the setpoint for the DP system of the main tugboat can also include the setpoint for the length of the towing cable between the main tugboat and the floating object. Considering the length of the towing cable improves the level of control over the towing situation and enhances the safety of the towing operation.

[0146] Further details of this method can be found in the description in the preceding sections of this disclosure.

[0147] The floating object can have actuators or propellers with characteristics different from those of the independent towing vessel. For precise control, these actuators or propellers can also be integrated into the system. When the propellers or actuators are controlled by the towing assistance system, the system can also prioritize the use of the propellers or actuators, as well as the towing vessel's propellers or actuators, based on their respective characteristics to optimize control of towing and installation operations. The floating object is equipped with a wireless two-way transmission device for sending information to the main towing vessel and receiving information, including setpoint information, from the towing assistance system. An example of two-way communication between the floating object and the main towing vessel is shown below. Figure 6 and Figure 7 As shown.

[0148] Floating objects that can be equipped with actuators or propulsion systems include, but are not limited to, semi-submersible drilling platforms, floating aquaculture farms, ships, drilling platforms, jack-up vessels, and FPSOs.

[0149] In an exemplary method, a floating object is towed by a main tugboat and at least one auxiliary tugboat, wherein the main tugboat and at least one auxiliary tugboat are connected to the floating object via towing cables. The main tugboat is equipped with a towing assistance system. The towing assistance system receives at least one first input parameter from at least one sensor on the floating object. The at least one sensor may include a position sensor for measuring the position of the floating object in at least three degrees of freedom. The towing assistance system calculates a setpoint for the main tugboat, at least one auxiliary tugboat, and the floating object based on at least one first input parameter from the floating object, at least one second input parameter from at least one auxiliary tugboat, and at least one third input parameter from the main tugboat.

[0150] The towing assistance system calculates the setpoint of at least one thruster or actuator on the floating object. At least one first input parameter from the floating object may include a force vector from any thruster or actuator on the floating object.

[0151] The setpoint calculated by the DP system can include the force vector of any thruster or actuator connected to the floating object.

[0152] Further details of this method can be found in the description in the preceding sections of this disclosure.

[0153] The foregoing has described exemplary embodiments of the present invention. It will be apparent to those skilled in the art that other embodiments incorporating these concepts may also be employed. The above and other examples are intended to be illustrative only, and the true scope of the invention should be determined by the following claims.

Claims

1. A system for assisting in a towing operation of a floating object, the system comprising: - a floating object comprising a wireless communication system and at least one position sensor for measuring a position of the floating object in at least three degrees of freedom; - a main tugboat connectable to the floating object by a towline, the main tugboat comprising a winch, a DP system, a two-way wireless communication system, and a towing assistance system / controller, wherein the towing assistance system is integrated with the DP system; - at least one auxiliary tugboat connectable to the floating object by a towline, the at least one auxiliary tugboat comprising a two-way wireless communication system; - wherein the towing assistance system is configured to calculate a setpoint for the DP system of the main tugboat based on at least one first input parameter from the floating object, at least one second input parameter from the at least one auxiliary tugboat, and at least one third input parameter from the main tugboat.

2. The system of claim 1, wherein, The towing assistance system is further configured to calculate a setpoint for a winch control system of the main tugboat.

3. The system of claim 2, wherein, The setpoint for the winch control system comprises at least one of a tension of the towline and a length of the towline.

4. The system of claim 1 or claim 2, wherein, The calculated setpoint for the DP system further comprises a length of the towline.

5. The system of one of claims 1 to 4, wherein, The towing assistance system is configured to calculate a setpoint for the at least one auxiliary tugboat.

6. The system of one of claims 1 to 4, wherein, The towing assistance system is configured to calculate a setpoint for at least one thruster or actuator on the floating object.

7. The system according to one of claims 1 to 6, wherein, The at least one first input parameter from the floating object comprises a motion of the floating object comprising at least one of a surge, a sway, and a yaw.

8. The system of one of claims 1 to 7, wherein, The at least one first input parameter from the floating object comprises a force vector from any thruster or actuator on the floating object.

9. The system of one of claims 1 to 8, wherein, The at least one first input parameter from the floating object comprises a motion of the floating object comprising at least one of a heave, a roll, and a pitch.

10. The system of one of claims 1 to 9, wherein, The at least one first input parameter from the floating object comprises a velocity and an acceleration of the floating object in six degrees of freedom.

11. The system of one of claims 1 to 10, wherein, The at least one second input parameter from the at least one auxiliary tugboat comprises a propulsion force of the at least one auxiliary tugboat and a direction of the at least one auxiliary tugboat.

12. The system of one of claims 1 to 11, wherein, The at least one second input parameter from the at least one auxiliary tugboat comprises a position of the at least one auxiliary tugboat in at least three degrees of freedom.

13. The system of one of claims 1 to 12, wherein, The at least one second input parameter from the at least one auxiliary tugboat comprises at least one of: - a motion of the auxiliary tugboat comprising at least one of a heave, a sway, a surge, a roll, a pitch, and a yaw; - a tension on the towline between the auxiliary tugboat and the floating object; - a length of the towline between the auxiliary tug and the floating object.

14. The system of one of claims 1 to 13, wherein, The at least one third input parameter from the main tug comprises a propulsion force of a propeller of the main tug and a heading of the main tug.

15. The system of one of claims 1 to 14, wherein, The at least one third input parameter from the main tug comprises a position of the main tug in at least three degrees of freedom.

16. The system of one of claims 1 to 15, wherein, The at least one third input parameter from the main tug comprises at least one of: - a motion of the main tug, the motion of the main tug comprising at least one of heave, sway, surge, roll, pitch and yaw; - a tension on the towline between the main tug and the floating object; - a catenary of the towline between the main tug and the floating object; - a length of the towline between the main tug and the floating object; - an output from a winch control system of the main tug.

17. The system of one of claims 1 to 16, wherein, The auxiliary tug further comprises a DP system.

18. The system of one of claims 1 to 17, wherein, The auxiliary tug further comprises a winch with a winch control system.

19. The system of one of claims 1 to 18, wherein, The floating object further comprises at least one of a satellite navigation system, an inertial measurement unit or an inertial navigation system.

20. The system of one of claims 1 to 19, wherein, The inertial measurement unit is at least one of a motion reference unit (MRU) and a motion gyrocompass (MGC).

21. The system of one of claims 1 to 20, wherein, The floating object comprises a differential GPS, motion sensors and a gyrocompass.

22. A towing assistance system for assisting in a towing operation of a floating object, the system comprising: - an interface for integrating the towing assistance system with a DP system to enable the towing assistance system to receive at least one input parameter from the DP system and at least one input parameter from a winch control system; - an interface for receiving at least one first input parameter from the floating object; - wherein the towing assistance system is adapted to calculate a setpoint for a main tug and a setpoint for at least one auxiliary tug based on the at least one first input parameter from the floating object, at least one second input parameter from a winch control system on the at least one auxiliary tug, and at least one third input parameter from a DP system and a winch control system on the main tug.

23. The towing assistance system of claim 22, wherein, The towing assistance system is further adapted to calculate a setpoint for the winch control system of the main tug.

24. The towing assistance system according to one of claims 22 to 23, wherein, The setpoint of the winch control system comprises at least one of a tension of a towline and a length of a towline.

25. The towing assistance system according to one of claims 22 to 24, wherein, The setpoint of the main tug comprises a propulsion force of at least one propeller of the main tug and a heading of the main tug.

26. Towing assist system according to one of claims 22 to 25, wherein, The setpoint of the at least one auxiliary tug comprises a propulsion force of at least one propeller of the at least one auxiliary tug and a heading of the at least one auxiliary tug.

27. The towing assistance system according to one of claims 22 to 26, wherein, The calculated setpoint of the DP system further comprises a length of a towline.

28. The towing assistance system of one of claims 22 to 27, wherein, The calculated setpoint of the DP system further comprises a force vector of any propeller or actuator attached to the floating object.

29. The towing assistance system of one of claims 22 to 28, wherein, The at least one first input parameter from the floating object comprises a position of the floating object in at least three degrees of freedom.

30. The towing assistance system of one of claims 22 to 29, wherein, The at least one first input parameter from the floating object comprises motion of the floating object, the motion of the floating object comprising at least one of sway, surge and yaw.

31. The towing assistance system of one of claims 22 to 30, wherein, The at least one first input parameter from the floating object comprises velocity and acceleration of the floating object in six degrees of freedom.

32. The towing assistance system of one of claims 20 to 28, wherein, The at least one first input parameter from the floating object comprises motion of the floating object, the motion of the floating object comprising at least one of roll, pitch and heave.

33. The towing assistance system of one of claims 22 to 32, wherein, The at least one second input parameter from the at least one auxiliary tugboat comprises propulsion of the at least one auxiliary tugboat and heading of the at least one auxiliary tugboat.

34. The towing assistance system of one of claims 22 to 33, wherein, The at least one second input parameter from the auxiliary tugboat comprises position of the auxiliary tugboat in at least three degrees of freedom.

35. The towing assistance system of one of claims 22 to 34, wherein, The at least one second input parameter from the at least one auxiliary tugboat comprises motion of the auxiliary tugboat, the motion of the auxiliary tugboat comprising at least one of heave, sway, surge, roll, pitch and yaw.

36. The towing assistance system of one of claims 22 to 35, wherein, The at least one second input parameter from the at least one auxiliary tugboat comprises at least one of: - tension on the towline between the auxiliary tugboat and the floating object; or - length of the towline between the auxiliary tugboat and the floating object.

37. The towing assistance system of one of claims 22 to 36, wherein, The at least one third input parameter from the main tugboat comprises propulsion of a propeller of the main tugboat and heading of the main tugboat.

38. The towing assistance system of one of claims 22 to 37, wherein, The at least one third input parameter from the main tugboat comprises position of the at least one auxiliary tugboat in at least three degrees of freedom.

39. The towing assistance system of one of claims 22 to 38, wherein, The at least one third input parameter from the main tugboat comprises motion of the main tugboat, the motion of the main tugboat comprising at least one of sway, surge and yaw.

40. The towing assistance system of one of claims 22 to 39, wherein, The at least one third input parameter from the main tugboat comprises at least one of: - motion of the main tugboat, the motion of the main tugboat comprising at least one of heave, sway, surge, roll, pitch and yaw; - tension on the towline between the main tugboat and the floating object; - catenary of the towline between the main tugboat and the floating object; - length of the towline between the main tugboat and the floating object; - output from the winch control system of the main tugboat.

41. A main tugboat for assisting in a towing operation of a floating object, the main tugboat being connectable to the floating object by a towline, the main tugboat comprising: - at least one propeller; - a winch and a DP system; - a bidirectional wireless communication system; - a towing assistance system / controller, wherein the towing assistance system is integrated with the DP system; and - wherein the towing assistance system is adapted to calculate set points for the main tugboat and set points for at least one auxiliary tugboat based on at least one input parameter to assist in a towing operation of the floating object.

42. The host tug of claim 41, wherein, The tug assist system is further adapted to calculate a set point for a winch control system of the main tug boat.

43. A host tug as claimed in claim 41 or claim 42, wherein, The calculated set point for the DP system further comprises a length of a towline.

44. The mother tug boat according to one of claims 41 to 43, wherein, The at least one input parameter comprises at least one first input parameter from the floating object, at least one second input parameter from the at least one assist tug boat, and at least one third input parameter from the main tug boat.

45. The mother tugboat according to one of claims 41 to 44, wherein, The at least one first input parameter from the floating object comprises at least one of: - a motion of the floating object, the motion of the floating object comprising at least one of heave, sway, surge, roll, pitch and yaw; or - a velocity and an acceleration of the floating object in six degrees of freedom.

46. The mother tugboat according to one of claims 41 to 45, wherein, The tug assist system is integrated with the DP system and the winch control system.

47. The mother tugboat according to one of claims 41 to 46, wherein, Calculating a set point further comprises calculating a propulsion force of the at least one propeller of the main tug boat and calculating a heading of the main tug boat.

48. The mother tugboat according to one of claims 41 to 47, wherein, The at least one first input parameter from the floating object comprises at least one of: - a position of the floating object in at least three degrees of freedom; - a motion of the floating object, the motion of the floating object comprising at least one of heave, sway, surge, roll, pitch and yaw; - a velocity and an acceleration of the floating object in six degrees of freedom.

49. The mother tugboat according to one of claims 41 to 48, wherein, The at least one second input parameter from the at least one assist boat further comprises at least one of: - a propulsion force and a heading of the at least one assist boat; - a position of the at least one assist boat, preferably a position of the at least one assist boat in at least three degrees of freedom; - a motion of the at least one assist boat, the motion of the at least one assist boat comprising at least one of heave, sway, surge, roll, pitch and yaw; - a tension in a towline between the assist tug boat and the floating object; - a length of the towline between the assist tug boat and the floating object; - a catenary of the towline between the assist tug boat and the floating object; - an output from the DP system of the assist boat.

50. The mother tugboat according to one of claims 41 to 49, wherein, The at least one third input parameter from the main tug boat comprises a propulsion force of the propeller of the main tug boat and a heading of the main tug boat.

51. The mother tugboat according to one of claims 41 to 50, wherein, The at least one third input parameter from the main tug boat comprises a position of the main tug boat in at least three degrees of freedom.

52. The mother tugboat according to one of claims 41 to 51, wherein, The at least one third input parameter from the main tug boat comprises at least one of: - a motion of the main tug boat, the motion of the main tug boat comprising at least one of heave, sway, surge, roll, pitch and yaw; - a tension in the towline between the main tug boat and the floating object; - a catenary of the towline between the main tug boat and the floating object; - a length of the towline between the main tug boat and the floating object; - an output from the winch control system of the main tug boat.

53. A method for assisting in a towing operation of a floating object, the method comprising: - towing the floating object by a primary towing vessel and at least one secondary towing vessel, wherein the primary towing vessel and the at least one secondary towing vessel are connected to the floating object by means of a towline, wherein the primary towing vessel is provided with a towing assistance system; - receiving at least one first input parameter from at least one sensor on the floating object, wherein the at least one sensor comprises a position sensor for measuring a position of the floating object in at least three degrees of freedom; - wherein the towing assistance system is adapted to calculate setpoints for the primary towing vessel and the at least one secondary towing vessel based on the at least one first input parameter from the floating object, at least one second input parameter from the at least one secondary towing vessel, and at least one third input parameter from the primary towing vessel.

54. The method according to claim 53, further comprising calculating setpoints for a winch control system of the primary towing vessel, wherein preferably the setpoints for the winch control system comprise at least one of a tension of the towline and a length of the towline.

55. The method of claim 53, further comprising calculating set points for a DP system of the host tugboat, wherein, the setpoints comprise a length of the towline between the primary towing vessel and the floating object.

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