Water flow control system, control device, water flow control method, and program

Abstract

To adjust the quantities of water in a plurality of tanks be in an optimum state so that a control system of an underwater sailing body converges to a target value while carrying out coordination with an existent control system, considering the capability limitation of an actuator.SOLUTION: A water quantity control system controller includes: a feedback control unit for calculating a command value for a water quantity control system target value by calculation based on a feedback control method with the water quantity control system target value and a feedback value as input; a feed forward control unit for acquiring a prediction value for unbalanced amounts for an underwater sailing body when a state change occurs based on a state signal regarding the state change of the underwater sailing body affecting at least one of position or posture of the underwater sailing body; and an adjustment amount calculating unit for calculating an adjustment amount indicating increase / decrease in the water amount for each of the tanks by an optimization method with a command value and a prediction value as inputs and adjustment conditions regarding the water amounts of the plurality of tanks and state conditions indicating the state of the underwater sailing body as conditions.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a water volume control system control device, a control system, a water volume control method, and a program.

Background Art

[0002] For example, Patent Document 1 discloses a modular underwater vehicle in a plurality of cylindrical pressure-resistant containers. Some of the modules are provided with a tank for storing water called a ballast tank inside the pressure-resistant container. For example, by adjusting the water volume of a plurality of tanks by water transfer or injection / drainage, the buoyancy in the vertical direction of the underwater vehicle can be controlled to change the depth of the underwater vehicle. For example, the density of the underwater vehicle can be made equal to the density of water to bring the underwater vehicle into a neutral buoyancy state where it neither floats nor sinks. Also, by changing the balance of the water volume in the front and rear tanks of the underwater vehicle, the trim of the underwater vehicle can be controlled.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the underwater vehicle described in Patent Document 1, it is not specifically disclosed how to adjust the water transfer and injection / drainage for a plurality of tanks in order to control the buoyancy and trim. Also, in a manned underwater vehicle, a person performs operations of water transfer and injection / drainage for a plurality of tanks based on the states such as the depth and posture of the underwater vehicle. Therefore, there has never been a concept of performing water transfer and injection / drainage for a plurality of tanks by some automatic control means without the intervention of human operations when controlling the buoyancy and trim.

[0005] The number of possible combinations of procedures for transferring and filling / discharging water into multiple tanks on an underwater vehicle is enormous. Therefore, controlling the transfer and filling / discharging of water into multiple tanks can be considered as controlling a redundant, multi-input system. When operated by a human, many input operations are performed, such as calculating the adjustment amount to optimize the water volume in multiple tanks, coordinating with existing control systems that control rudders and thrusters, setting waiting times that take into account response delays caused by performance constraints such as the flow rate and response time of actuators such as pumps and valves, and minimizing the adjustment time required to adjust the water volume in the tanks. In order to realize these many input operations by an automated control system, a design guideline is needed that sets each of the things that humans consider when performing many input operations as a problem, and designs an automated control system that solves the set problems. However, there is a problem in that such a design guideline has not been established.

[0006] This disclosure has been made in view of such problems and aims to provide a water flow control system, control system, water flow control method, and program that optimize the water flow in multiple tanks so that the control system of an underwater vehicle converges to a target value, while taking into account the capacity constraints of the actuator and coordinating with existing control systems.

[0007] This disclosure was made to solve the above-mentioned problems and aims to provide a water volume control system, control system, water volume control method, and program that can optimize the water volume of multiple tanks so that the control system of an underwater vehicle converges to a target value, while taking into account the capacity constraints of the actuator and coordinating with existing control systems. [Means for solving the problem]

[0008] To solve the above problems, the water volume control system control device according to this disclosure includes a motion control device that controls the motion of an underwater vehicle, a motion control system control device that calculates a command value for the motion control device based on a motion control system target value and a control amount detected from the underwater vehicle, and a water volume control system control device that controls increasing or decreasing the water volume in each of the tanks of an underwater vehicle having a plurality of tanks and an actuator that adjusts the water volume in each of the tanks, wherein the command value for the water volume control system target value is calculated by a feedback control method that takes a water volume control system target value and a feedback value as inputs, compensates for the response delay of the actuator, and suppresses interference with the control band of the motion control system control device. The system includes: a feedback control unit; a feedforward control unit that receives a state signal relating to a change in the state of the underwater vehicle that affects at least one of the position and attitude of the underwater vehicle as input, and based on the state signal, obtains a predicted value of an unbalance amount including at least one of the unbalance weight and unbalance moment of the underwater vehicle when the change in state occurs; and an adjustment amount calculation unit that receives the command value calculated by the feedback control unit and the predicted value obtained by the feedforward control unit as input, and calculates an adjustment amount indicating an increase or decrease in the amount of water for each of the tanks by an optimization method that is set by adjustment conditions relating to the amount of water in a plurality of tanks and state conditions indicating the state of the underwater vehicle.

[0009] The control system according to this disclosure comprises: a motion control device for controlling the motion of an underwater vehicle; a motion control system control device that calculates a command value for the motion control device based on a motion control system target value and a control amount detected from the underwater vehicle; a plurality of tanks provided on the underwater vehicle; an actuator for adjusting the water volume in each of the tanks; and a water volume control system control device, wherein the water volume control system control device takes a water volume control system target value and a feedback value as inputs, and calculates a command value for the water volume control system target value by calculation using a feedback control method that compensates for the response delay of the actuator and suppresses interference with the control band of the motion control system control device. The system comprises a back control unit, a feedforward control unit that receives a state signal relating to a change in the state of the underwater vehicle that affects at least one of the position and attitude of the underwater vehicle as input, and based on the state signal, obtains a predicted value of an unbalance amount including at least one of the unbalance weight and unbalance moment of the underwater vehicle when the change in state occurs, and an adjustment amount calculation unit that receives the command value calculated by the feedback control unit and the predicted value obtained by the feedforward control unit as input, and calculates an adjustment amount indicating an increase or decrease in the amount of water for each of the tanks by an optimization method that is set by adjustment conditions relating to the amount of water in a plurality of tanks and state conditions indicating the state of the underwater vehicle.

[0010] The water volume control method according to this disclosure is a water volume control method for an underwater vehicle having a motion control device for controlling the motion of the underwater vehicle, a motion control system control device that calculates a command value for the motion control device based on a motion control system target value and a control amount detected from the underwater vehicle, a plurality of tanks, and an actuator for adjusting the water volume of each of the tanks, wherein the method calculates a command value for the water volume control system target value by calculation using a feedback control method that takes a water volume control system target value and a feedback value as inputs, compensates for the response delay of the actuator, and suppresses interference with the control band of the motion control system control device, takes a state signal relating to a change in the state of the underwater vehicle that affects at least one of the position and attitude of the underwater vehicle as inputs, obtains a predicted value of an unbalance amount including at least one of the unbalance weight and unbalance moment of the underwater vehicle when the change in state occurs based on the state signal, takes the calculated command value and the obtained predicted value as inputs, and calculates an adjustment amount indicating an increase or decrease in the water volume for each of the tanks by an optimization method that is set by adjustment conditions relating to the water volume of the plurality of tanks and state conditions indicating the state of the underwater vehicle.

[0011] The program relating to this disclosure causes a computer equipped in an underwater vehicle having a motion control device that controls the motion of the underwater vehicle, a motion control system control device that calculates a command value for the motion control device based on a target value of the motion control system and a control amount detected from the underwater vehicle, and a plurality of tanks and an actuator that adjusts the amount of water in each of the tanks, to execute the following steps: a procedure to calculate a command value for the target value of the water volume control system by calculation using a feedback control method that takes a target value of the water volume control system and a feedback value as inputs, compensates for the response delay of the actuators, and suppresses interference with the control band of the motion control system control device; a procedure to take a state signal relating to a change in the state of the underwater vehicle that affects at least one of the position and attitude of the underwater vehicle as inputs, and obtain a predicted value of an unbalance amount including at least one of the unbalance weight and unbalance moment of the underwater vehicle when the change in state occurs, based on the state signal; and a procedure to calculate an adjustment amount indicating an increase or decrease in the amount of water for each of the tanks by using an optimization method that takes the calculated command value and the obtained predicted value as inputs and is conditioned on adjustment conditions relating to the amount of water in the plurality of tanks and state conditions indicating the state of the underwater vehicle. [Effects of the Invention]

[0012] According to the water flow control system, control system, water flow control method, and program disclosed herein, the water flow in multiple tanks can be optimized so that the control system of the underwater vehicle converges to a target value, while taking into account the capacity constraints of the actuators and coordinating with existing control systems. [Brief explanation of the drawing]

[0013] [Figure 1] This block diagram shows the configuration of the control system according to the first embodiment and the relationship between the forces and moments acting on the underwater vehicle. [Figure 2] This is a block diagram showing the configuration of the tank system according to the first embodiment. [Figure 3] This is a block diagram showing the control system of the control system of the first embodiment. [Figure 4]This figure shows the procedure for determining the calculation formula for the optimal solution to be applied to the adjustment amount calculation unit of the first embodiment. [Figure 5] This block diagram shows the configuration of the control system in the second embodiment and the relationship between the forces and moments acting on the underwater vehicle. [Figure 6] This is a block diagram showing the configuration of the feedforward control unit in the second embodiment. [Figure 7] This is a block diagram showing the configuration of the first feedforward control unit in the second embodiment. [Figure 8] This figure shows an example of correlation data between forward speed and unbalanced weight stored in the first feedforward control unit according to the second embodiment. [Figure 9] This figure shows an example of correlation data between forward speed and unequilibrium moment stored in the first feedforward control unit according to the second embodiment. [Figure 10] This figure shows an example of correlation data between propeller rotation speed and forward speed stored in the first feedforward control unit according to the second embodiment. [Figure 11] This is a block diagram showing the configuration of the second feedforward control unit in the second embodiment. [Figure 12] This figure shows an example of data indicating the correlation between water temperature, depth, and discharge volume, stored in the second feedforward control unit according to the second embodiment. [Figure 13] This is a block diagram showing the configuration of the third feedforward control unit in the second embodiment. [Figure 14] This figure shows the physical parameters and units included in the formula used in the second embodiment. [Figure 15] This diagram shows the processing flow by the motion control system control device and rudder control device of the second embodiment. [Figure 16] This figure shows the processing flow of the water volume control system and tank system according to the second embodiment. [Figure 17] This is Figure (1) showing a graph of the simulation results using the control system of the second embodiment. [Figure 18] This is Figure (2) showing a graph of the simulation results using the control system of the second embodiment. [Figure 19] This figure shows an example of the hardware configuration of the control system according to the first and second embodiments. [Modes for carrying out the invention]

[0014] (First Embodiment) The embodiments of this disclosure will be described below with reference to the drawings. To summarize the challenges in realizing the considerations that humans have when performing the numerous input operations described above as an automatic control means, three challenges need to be addressed: (Challenge 1) compensating for response delays caused by actuator capability constraints; (Challenge 2) minimizing interference between the control bandwidth of the water volume control system that controls the water volume of multiple tanks and the control bandwidth of the motion control system in order to coordinate with the existing motion control system; and (Challenge 3) calculating the optimal water volume adjustment amount for each of the multiple tanks so that the entire control system, including the motion control system, converges in parallel toward a specified target value when controlling buoyancy and trim. The following describes design guidelines for an automatic control system to solve these three challenges, with reference to the control system 100 of the first embodiment.

[0015] (Control system of the first embodiment) Figure 1 is a block diagram showing an example of the configuration of the control system 100 according to the first embodiment, and the relationship between the forces and moments acting on the underwater vehicle 6 as a result of the control by the control system 100. Here, the underwater vehicle 6 is, for example, a manned underwater vehicle on board. The control system 100 comprises a water volume control system control device 1, a tank system 2, a motion control system control device 3, a motion control device 4, and a detection unit 5. Although Figure 1 is a block diagram that includes the underwater vehicle 6 as a structure to show the relationship of the entire control system, in reality, the control system 100 is a system installed on the underwater vehicle 6. Also, in Figure 1, solid lines indicate electrical connections, and dashed lines indicate the forces and moments acting on the underwater vehicle 6.

[0016] The tank system 2 is controlled by the water volume control system control device 1 and comprises an actuator 21 and a tank 22. Figure 2 is a block diagram showing the detailed configuration of the tank system 2. The tank 22 is a so-called ballast tank and, as shown in Figure 2, includes, for example, five tanks 22-1 to 22-5. Tank 22-1 is, for example, a tank positioned in front of the underwater vehicle 6, and tank 22-5 is, for example, a tank positioned behind the underwater vehicle 6. Tanks 22-2 to 22-4 are positioned between tanks 22-1 and 22-5, for example, around the center of gravity of the underwater vehicle 6.

[0017] For example, when water is poured into each of the tanks 22-1 to 22-5, the buoyancy of the underwater vehicle 6 decreases, causing the underwater vehicle 6 to sink. Conversely, when water is discharged from each of the tanks 22-1 to 22-5, buoyancy is generated for the underwater vehicle 6, causing it to float. It is also possible to adjust the amount of water in each of the tanks 22-1 to 22-5 by transferring water from one of the tanks 22-1 to 22-5 to the other tanks 22-1 to 22-5.

[0018] In this way, by adjusting the amount of water stored in tanks 22-1 to 22-5, the vertical direction of movement of the underwater vehicle 6 in the water can be adjusted, for example, as shown by arrow 51, and the depth, which is the distance from the water surface, can be arbitrarily changed. Furthermore, by making the density of the underwater vehicle 6 equal to the density of the water, it is possible to make the underwater vehicle 6 neither float nor sink, i.e., to achieve a neutral buoyancy state where the depth is constant. Also, by reducing the amount of water in tank 22-1 and increasing the buoyancy in front of the underwater vehicle 6, a trim tilt is created that points the front of the underwater vehicle 6 upward. Conversely, by reducing the amount of water in tank 22-5 and increasing the buoyancy in rear of the underwater vehicle 6, a trim tilt is created that points the front of the underwater vehicle 6 downward. As a result, as shown by arrow 52, ​​the pitch angle, which is one of the attitude angles of the underwater vehicle 6 in the water, can be adjusted to any angle. Furthermore, for example, by positioning tanks 22-2 and 22-3 near the center of gravity of the underwater vehicle 6, at symmetrical positions on either side of the roll axis, which is the central axis extending from front to rear, and by changing the balance of the water volume in tanks 22-2 and 22-3, the roll angle, which is one of the attitude angles of the underwater vehicle 6, can be adjusted to any angle.

[0019] As shown in Figure 2, the actuator 21 includes, for example, pumps 21P-1 to 21P-7 and valves 21V-1 to 21V-15. Pumps 21P-1 to 21P-7 and valves 21V-1 to 21V-15 each have a built-in drive mechanism, such as a motor. When each of the pumps 21P-1 to 21P-7 receives a control signal to turn it ON, the drive mechanism operates to take in water stored in tanks 22-1 to 22-5 connected to it via piping and discharge it through the other piping. When it receives a control signal to turn it OFF, the drive mechanism stops and water intake stops. When the valves 21V-1 to 21V-15 receive a control signal to turn them ON, the drive mechanism operates to open the valve, and when it receives a control signal to turn them OFF, the drive mechanism operates to close the valve. By switching pumps 21P-1 to 21P-7 and valves 21V-1 to 21V-15 ON / OFF using control signals, water is supplied to and drained from tanks 22-1 to 22-5, and water is transferred.

[0020] In Figure 2, as an example, tank 22 is shown containing five tanks 22-1 to 22-5. However, the number of tanks included in tank 22 is not limited to five; any number of multiple tanks is acceptable. Also, the number and arrangement of pumps 21P-1 to 21P-7 and valves 21V-1 to 21V-15 in Figure 2 are examples and will increase or decrease depending on the number of tanks 22-1 to 22-5. Furthermore, for example, if the specification is that filling and draining is performed only from tank 22-3, the arrangement will differ according to that specification, and pump 21P-3 for filling and draining tank 22-3, valves 21V-3 and 21V-8, and pumps 21P-6 and 21P-7 for water transfer, and valves 21V-11 to 21V-15 will be provided.

[0021] As shown by the dashed arrows in Figure 1, the underwater vehicle 6 is subjected to buoyancy forces and moments generated by the tank 22, forces and moments from the motion control device 4, and forces and moments from disturbances such as changes in seawater density when the underwater vehicle 6 is located in the sea. These forces and moments cause changes in the depth, pitch angle, roll angle, etc., of the underwater vehicle 6. The detection unit 5 is a sensor such as a gyroscope and detects control quantities corresponding to each of the control indicators related to the state of the underwater vehicle 6, such as attitude angles like pitch angle and roll angle, and depth. The detection unit 5 outputs the detected control quantities as feedback values ​​to the motion control system control device 3 and the water volume control system control device 1.

[0022] The motion control system control device 3 calculates a command value for the motion control device 4 based on a motion control system target value that corresponds to a predetermined control index and can be set to an arbitrary value, and a control amount detected by the detection unit 5 that corresponds to a predetermined control index. The motion control device 4 is, for example, a control device that includes a rudder and thrusters, and drives the rudder and thrusters based on the command value calculated by the motion control system control device 3 to adjust the attitude, direction of movement, speed of movement, etc., of the underwater vehicle 6.

[0023] The water volume control system control device 1 is a device that adjusts the water volume of a tank 22, which is part of a tank system 2 that is a control target of a redundant multi-input system. The water volume control system control device 1 comprises a first calculation unit 11, a feedback control unit 12, a feedforward control unit 15, a second calculation unit 16, an adjustment amount calculation unit 13, and an actuator control unit 14. The feedback control unit 12 is a functional unit provided to solve the above-mentioned (problem 1) and (problem 2). The feedforward control unit 15 is a functional unit provided to solve the above-mentioned (problem 1). The adjustment amount calculation unit 13 is a functional unit provided to solve the above-mentioned (problem 3). The design guidelines for the feedback control unit 12, the feedforward control unit 15, and the adjustment amount calculation unit 13 will be described below.

[0024] (Design guidelines for feedback control unit) The control system 100 in Figure 1 can be represented in Figure 3 as a block diagram of the control system. In Figure 3, the water flow control system 61 is a transmission element corresponding to the water flow control system control device 1 and the tank system 2. The motion control system 67 is a transmission element corresponding to the motion control system control device 3 and the motion control device 4. The controlled object 65 is a transmission element corresponding to the underwater vehicle 6, which is a structure controlled by force and moment. The summing point 60 takes in the target value of the water flow control system and the control amount output by the controlled object 65, subtracts the control amount from the target value of the water flow control system to calculate the error, and outputs the calculated error to the water flow control system 61. The summing point 64 takes in the force and moment output by the motion control system 67, the force and moment output by the water flow control system 61, and the force and moment due to disturbances, adds them together for each force and moment, and outputs the summed force value and summed moment value to the controlled object 65. The summing point 66 takes in the target value of the motion control system and the control variable output by the controlled object 65, subtracts the control variable from the target value of the motion control system to calculate the error, and outputs the calculated error to the motion control system 67.

[0025] The water flow control system 61 includes a transfer element 63 that simulates the response delay caused by the capacity constraint of the actuator 21, as described in (Problem 1) above, in order to compensate for the response delay caused by the capacity constraint of the actuator 21. The transfer element 63 performs calculations using the transfer function of a first-order lag system shown in equation (1). The parameter T in equation (1) a This is set to simulate the response delay caused by the capability constraints of actuator 21.

[0026]

number

[0027] Furthermore, the water volume control system 61 includes a transmission element 62 that performs calculations using the PID control method shown in the following equation (2) in order to suppress interference between the control band of the water volume control system that controls the water volume of the multiple tanks 22-1 to 22-5 described above (Problem 2) and the control band of the motion control system.

[0028]

number

[0029] Based on the block diagram in Figure 3, the control system was designed, and the control gain of the PID control system, i.e., the parameter K in equation (2), was set so that the control system converges through feedback control. pt ,T it ,T dt The following is determined. In this design, the most ideal state is to design the control bandwidth of the motion control system 67 and the control bandwidth of the water flow control system 61 to be completely non-interfering. However, in actual design, while confirming that the control bandwidth of the motion control system 67 and the control bandwidth of the water flow control system 61 do not interfere with each other and cause hunting etc. in the controlled object 65, the parameter K is set such that the control bandwidth of the water flow control system 61 is sufficiently small compared to the control bandwidth of the motion control system 67. pt ,T it ,T dtwill be determined. The forces and moments obtained by controlling the tank 22 in the water volume control system 61 are greater than the forces and moments obtained by controlling the rudder, thruster, etc. in the motion control system 67. However, from the perspective of the response time until the effects of the forces and moments appear, the response time of the motion control system 67 is shorter than that of the water volume control system 61. Therefore, even if the frequency of the control band of the water volume control system 61 is lowered, the influence on the control of the tank 22 is small. For example, in the frequency domain, the control band of the water volume control system 61 is designed to be sufficiently smaller than the control band of the motion control system 67.

[0030] By performing the above design to obtain appropriate parameters K pt , T it , T dt it is possible to prevent destabilization due to the capacity constraint of the actuator 21 and realize a stable control system that does not exceed the capacity constraint of the actuator 21. Also, it is possible to realize a control system that suppresses the interference between the control band of the motion control system 67 and the control band of the water volume control system 61. Thereby, it becomes possible to perform coordinated control in the motion control system 67 and the water volume control system 61. Therefore, by performing feedback control to converge the control amount output by the control target 65 to the motion control system target value and the water volume control system target value, it is possible to solve (Problem 1) and (Problem 2).

[0031] The first calculation unit 11 of the water volume control system control device 1 in FIG. 1 is a functional unit that performs calculations corresponding to the addition point 60, and takes in a water volume control system target value corresponding to a predetermined control index and specified as an arbitrary value, and a control amount detected by the detection unit 5 and corresponding to a predetermined control index. The first calculation unit 11 subtracts the control amount from the water volume control system target value to calculate an error, and outputs the calculated error to the feedback control unit 12. The feedback control unit 12 uses the parameters K pt , T it , T dtThis is a PID controller that performs PID control calculations corresponding to the defined transmission element 62. The feedback control unit 12 calculates a command value from the error output by the first calculation unit 11 through PID control calculations. The feedback control unit 12 outputs the calculated command value to the adjustment amount calculation unit 13.

[0032] In addition, at least one control indicator is predetermined, and if multiple control indicators are predetermined, the first calculation unit 11 will take in the target value and control amount of the water flow control system corresponding to each of the multiple control indicators. In this case, the feedback control unit 12 will calculate multiple command values ​​corresponding to each of the multiple control indicators based on each of the multiple errors corresponding to each of the multiple control indicators output by the first calculation unit 11.

[0033] (Design guidelines for feedforward control units) Furthermore, the water flow control system 61 includes a feedforward controller 68 to compensate for the response delay caused by the capability constraint of the actuator 21, as described in (Problem 1) above. The feedforward control unit 15 of the water flow control system control device 1 in Figure 1 is a functional unit that performs calculations corresponding to the feedforward controller 68. When a state signal related to a change in the state of the underwater vehicle 6 that affects at least one of its position and attitude is input to the feedforward control unit 15, it predicts the amount of unbalance occurring in the underwater vehicle 6 by feedforward control. Examples of changes in the state of the underwater vehicle 6 that affect at least one of its position and attitude include changes in the forward speed of the underwater vehicle 6, changes in attitude angles such as pitch angle and roll angle, changes in depth, and changes in the weight balance of the underwater vehicle 6. State signals related to these changes in state are input from, for example, an operating system (not shown) for operating the rudder or thrusters of the underwater vehicle 6. When the feedforward control unit 15 receives a status signal related to these state changes, it obtains a predicted value of the unbalance amount that will occur when the state change occurs, based on the status signal. The unbalance amount that occurs in the underwater vehicle 6 includes at least one of the unbalance weight and unbalance moment of the underwater vehicle 6.

[0034] In Figure 3, the summation point 69 adds the command value calculated by the feedback control unit 12 and the predicted value acquired by the feedforward control unit 15, and outputs the result to the summation point 64. The second calculation unit 16 in Figure 1 is a functional unit that performs the calculation corresponding to the summation point 69.

[0035] (Design guidelines for the adjustment amount calculation unit) The adjustment amount calculation unit 13 is a functional unit provided to solve (Problem 3) as described above. As a technology to solve (Problem 3), the Lagrange multiplier method is adopted, which allows for easy implementation in embedded devices and easy parameter changes on-site, and which enables the acquisition of an analytically optimal solution. Below, an example of the procedure for applying the calculation formula for the optimal solution obtained by analysis using the Lagrange multiplier method to the adjustment amount calculation unit 13 will be explained with reference to Figure 4.

[0036] To use the Lagrange multiplier method, the objective function and constraints in Lagrange's equations are set in advance (step S1). Here, the objective function is a function that represents the adjustment conditions for the water volume in tanks 22-1 to 22-5. The adjustment conditions for the water volume in tanks 22-1 to 22-5 include, for example, the condition of minimizing the energy consumption required to adjust the water volume, the condition of equalizing the amount of water distributed to each of tanks 22-1 to 22-5, and the condition of minimizing the adjustment time required to adjust the water volume. Here, as an example, the condition of minimizing the energy consumption required to adjust the water volume is defined as the objective function f1(x1,x2), and the condition of equalizing the amount of water distributed to each of tanks 22-1 to 22-5 is defined as the objective function f2(x1,x2).

[0037] A constraint condition is a function that indicates the state conditions of the underwater vehicle 6. State conditions that indicate the state of the underwater vehicle 6 include, for example, conditions that set the unequilibrium quantities related to the state of the underwater vehicle 6, such as depth and attitude angle, to target values. For example, if the objective is to bring the state of the underwater vehicle 6, such as depth and attitude, to equilibrium, the target value would be set to "0". Here, as an example, we define two constraint conditions as state conditions: constraint condition g1(x1,x2) which sets the vertical unequilibrium quantity of the underwater vehicle 6 to a target value, and constraint condition g2(x1,x2) which sets the pitch axis unequilibrium quantity of the underwater vehicle 6 to a target value. Also, here, to show a general example, we show two variables x1 and x2 in the objective function and constraint conditions, but in the case of the control system 100 in Figure 1, the amount of water adjustment for each of the five tanks 22-1 to 22-5 is a variable, so five variables are defined.

[0038] In step S1, the Lagrangian multipliers λ1 and λ2 are added to the set objective functions f1(x1,x2) and f2(x1,x2), and the constraint conditions g1(x1,x2) and g2(x1,x2) to formulate the Lagrangian equations (step S2). By analysis using the Lagrangian multiplier method, the functions h1(·,·) and h2(·,·), which calculate the optimal solutions for x1 and x2 for the input values ​​u1 and u2, are found (step S3). Here, the input values ​​u1 and u2 correspond to the sum of the command value output by the feedback control unit 12 of the water flow control system control device 1 in Figure 1 and the predicted value acquired by the feedforward control unit 15. Note that in Figure 4, as an example, two input values ​​u1 and u2 and two output values ​​x1 and x2 are shown, but the number of input values ​​and output values ​​do not have to match.

[0039] A computer that executes the calculation formulas for the functions h1(·,·) and h2(·,·) which calculate the optimal solutions for x1 and x2, is implemented as the adjustment amount calculation unit 13 (step S4). As a result, the adjustment amount calculation unit 13 can calculate the optimal adjustment amount for the water volume for each of the tanks 22-1 to 22-5 based on the command value calculated by the feedback control unit 12, the predicted value acquired by the feedforward control unit 15, and the calculation formula for calculating the optimal solution obtained by the above procedure. Therefore, the adjustment amount calculation unit 13 can solve (problem 3).

[0040] By solving (Problem 3), for example, by defining three conditions as the objective function—the condition of minimizing the energy consumption required to adjust the water volume, the condition of equalizing the amount of water distributed to each of the tanks 22-1 to 22-5, and the condition of minimizing the adjustment time required to adjust the water volume—the control system 100 will provide the following three effects. Specifically, if the condition of minimizing the energy consumption required to adjust the water volume is set, for example, the operating rate of pumps 21P-1 to 21P-7 can be reduced, which in turn contributes to reducing the lifespan of the underwater vehicle 6 by reducing its usage frequency. Also, if the condition of equalizing the amount of water distributed to each of the tanks 22-1 to 22-5 is set, the amount of water stored in each of the tanks 22-1 to 22-5 can be equalized. When any of the tanks 22-1 to 22-5 is full, depending on the specifications of the tank system 2, the response time for transferring water or filling and draining water from tanks 22-1 to 22-5 may be longer. In such cases, by equalizing the amount of water stored in each of the tanks 22-1 to 22-5, the response time of the tank system 2 can be equalized when adjusting the water volume in tanks 22-1 to 22-5 next. Furthermore, if the condition is set to minimize the adjustment time required for adjusting the water volume, for example, the time required for adjusting the transfer or filling / draining of water to tanks 22-1 to 22-5 can be shortened, making it possible to stabilize the depth, attitude, and other conditions of the underwater vehicle 6 in a short time.

[0041] Returning to Figure 1, the actuator control unit 14 generates control signals to turn ON or OFF the respective drive means of the actuators 21, namely pumps 21P-1 to 21P-7 and valves 21V-1 to 21V-15, based on the adjustment amounts for each of the tanks 22-1 to 22-5 calculated by the adjustment amount calculation unit 13 and the conversion rule data pre-stored in the internal memory area. As described above, the specifications for water transfer and filling / draining of the tank system 2 vary depending on the product adopted. For example, in addition to specifications where filling / draining is performed only in tank 22-3, there are also specifications where, if filling / draining is being performed in tank 22-3, water cannot be transferred from the other tanks 22-1, 22-2, 22-4, and 22-5 to tank 22-3. Furthermore, the format of the control signals for turning ON or OFF also varies depending on the product. Therefore, the actuator control unit 14 stores conversion rule data that reflects product-specific rules and product-specific logic in its internal memory area in advance, and uses this conversion rule data to generate ON / OFF control signals for the actuator 21 from the adjustment amount calculated by the adjustment amount calculation unit 13. As the actuator control unit 14, for example, a rule-based water transfer / injection / drainage controller equipped with the said conversion rule data may be used.

[0042] As shown in the first embodiment described above, we were able to provide design guidelines for a feedback control unit 12 that solves the problems of compensating for the response delay caused by the capability constraints of the actuator 21 (Problem 1) and suppressing interference between the control bandwidth of the water volume control system that controls the water volume of multiple tanks 22-1 to 22-5 and the control bandwidth of the motion control system in order to cooperate with the existing motion control system (Problem 2). We were also able to provide design guidelines for a feedforward control unit 15 that solves the problem of compensating for the response delay caused by the capability constraints of the actuator 21 (Problem 1). Furthermore, we were able to provide design guidelines for an adjustment amount calculation unit 13 that solves the problem of calculating the optimal water volume adjustment amount for each of the multiple tanks 22-1 to 22-5 so that the entire control system, including the motion control system, converges in parallel toward a target value specified when controlling buoyancy and trim (Problem 3). By providing a feedback control unit 12 and an adjustment amount calculation unit 13 designed based on these design guidelines, it becomes possible to reduce the burden of many input operations that previously had to be performed by a person on the tank system 2. Furthermore, the adjustment amount calculation unit 13 executes a calculation formula to calculate the optimal water volume adjustment amount for tanks 22-1 to 22-5, which are determined by arbitrarily defined adjustment conditions and state conditions. This makes it possible to construct a control system 100 that is tailored to the purpose of controlling the underwater vehicle 6 and to the state of the underwater vehicle 6, such as its depth and attitude. Consequently, the control system 100 makes it possible to optimize the water volumes of multiple tanks so that the control system of the underwater vehicle 6 converges to a target value, while taking into account the capacity constraints of the actuator 21 and coordinating with the existing control system.

[0043] (Second embodiment) In the second embodiment, a more specific configuration designed in accordance with the design guidelines for the feedback control unit 12, feedforward control unit 15, and adjustment amount calculation unit 13 shown in the first embodiment will be described. Figure 5 is a block diagram showing an example of the configuration of the control system 100a according to the second embodiment and the relationship between the forces and moments acting on the underwater vehicle 6a as a result of the control by the control system 100a. In the control system 100a, components identical to those of the control system 100 are denoted by the same reference numerals, and different components will be described below.

[0044] The control system 100a comprises a water volume control system control device 1a, a tank system 2, a motion control system control device 3a, a rudder control device (motion control device) 4a, and a detection unit 5a. The underwater vehicle 6a is a manned underwater vehicle, similar to the underwater vehicle 6 of the first embodiment, for example, a vehicle on which a person rides. Figure 5, like Figure 1, is a block diagram that includes the underwater vehicle 6a as a structure to show the relationship of the entire control system, but in reality, the control system 100a is a system installed on the underwater vehicle 6a. Also, in Figure 5, as in Figure 1, solid lines indicate electrical connections, and dashed lines indicate forces and moments acting on the underwater vehicle 6a.

[0045] Adders 7 and 8 are not actual functional units, but rather functional units for the convenience of explanation to concisely illustrate the relationship between forces and moments acting on the underwater vehicle 6a. Adder 7 adds the buoyancy generated by the tank 22 and the force generated by the depth-adjusting rudder included in the rudder control device 4a (hereinafter referred to as the depth-adjusting rudder), and outputs the sum of the added forces. Adder 7 also adds the moment of the buoyancy generated by the tank 22 and the moment generated by the pitch-angle-adjusting rudder included in the rudder control device 4a (hereinafter referred to as the pitch-adjusting rudder), and outputs the sum of the added moments. Adder 8 adds the sum of the forces output by adder 7 and the force due to disturbance (F d The sum of the moments output by adder 7 and the moment due to disturbance (M) is added. The force added by adder 8 acts on the underwater vehicle 6a. In addition, adder 8 adds the sum of the moments output by adder 7 and the moment due to disturbance (M) d) and are added together. The moment added by the adder 8 acts on the underwater vehicle 6a. As a result, the force output by the adder 7 acts on the underwater vehicle 6a in the vertical direction, and the moment output by the adder 7 acts on the underwater vehicle 6a in the pitch axis direction.

[0046] The detection unit 5a detects two control variables, depth and pitch angle, which are control indicators for the underwater vehicle 6a. The unit of depth is, for example, [m], and the unit of pitch angle is, for example, [rad]. The detection unit 5a outputs the detected depth and pitch angle to the motion control system control device 3a.

[0047] The motion control system control device 3a comprises calculation units 31-1 and 31-2, a depth FB (Feed Back) control unit 32-1, and a pitch angle FB control unit 32-2. The calculation unit 31-1 takes in a depth target value, which is a motion control system target value corresponding to a predetermined depth control index and can be specified to any value, and the depth control amount detected by the detection unit 5a. The calculation unit 31-1 calculates an error by subtracting the depth control amount from the depth target value and outputs the calculated error to the depth FB control unit 32-1. The unit of the depth target value is [m], the same as the depth control amount detected by the detection unit 5a. The depth FB control unit 32-1 calculates a rudder angle command value for the depth adjustment rudder (hereinafter referred to as the depth adjustment rudder angle command value) based on the error output by the calculation unit 31-1. The depth FB control unit 32-1 outputs the calculated depth adjustment rudder angle command value (δb) to the rudder control device 4a and the water volume control system control device 1a.

[0048] The calculation unit 31-2 takes in a pitch angle target value, which is a motion control system target value corresponding to a predetermined pitch angle control index and can be specified to an arbitrary value, and the pitch angle control amount detected by the detection unit 5a. The calculation unit 31-2 subtracts the pitch angle control amount from the pitch angle target value to calculate an error and outputs the calculated error to the pitch angle FB control unit 32-2. The unit of the pitch angle target value is [rad], the same as the pitch angle control amount detected by the detection unit 5a. The pitch angle FB control unit 32-2 calculates a rudder angle command value for the pitch angle adjustment rudder (hereinafter referred to as the pitch angle adjustment rudder angle command value) based on the error output by the calculation unit 31-2. The pitch angle FB control unit 32-2 outputs the calculated pitch angle adjustment rudder angle command value (δr) to the rudder control device 4a and the water flow control system control device 1a.

[0049] The rudder control device 4a is a control device that controls the direction of the rudder, including the depth adjustment rudder and the pitch angle adjustment rudder, provided on the underwater vehicle 6a. The rudder control device 4a adjusts the direction of the depth adjustment rudder based on the depth adjustment rudder angle command value (δb) output by the depth FB control unit 32-1. The rudder control device 4a adjusts the direction of the pitch angle adjustment rudder based on the pitch angle adjustment rudder angle command value (δr) output by the pitch angle FB control unit 32-2.

[0050] In the control system 100 of the first embodiment, the control amount detected by the detection unit 5 is fed back to the water flow control system control device 1 as a feedback value. In contrast, in the control system 100a of the second embodiment, as described above, the depth adjustment rudder angle command value (δb) calculated by the depth FB control unit 32-1 and the pitch angle adjustment rudder angle command value (δr) calculated by the pitch angle FB control unit 32-2 are fed back to the water flow control system control device 1a as feedback values. As in the first embodiment, the water flow control system control device 1a referring to the control amount detected by the detection unit 5a as a feedback value has the advantage of a shorter response time because it does not go through the motion control system control device 3a. In contrast, the depth adjustment rudder angle command value (δb) calculated by the motion control system control device 3a reflects the depth control amount detected by the detection unit 5a, and the pitch angle adjustment rudder angle command value (δr) reflects the pitch angle control amount detected by the detection unit 5a. In other words, the two rudder angle command values, the depth adjustment rudder angle command value (δb) and the pitch angle adjustment rudder angle command value (δr), contain information from the control of each rudder by the rudder control device 4a, in addition to the control amount detected by the detection unit 5a. Therefore, when the water flow control system control device 1a refers to the rudder angle command value calculated by the motion control system control device 3a as a feedback value, although the response time will be longer, the fact that the rudder angle command value contains information from the rudder control has the advantage of making it easier for the water flow control system control device 1a and the motion control system control device 3a to cooperate.

[0051] The water volume control system control device 1a comprises a first calculation unit 11-1, 11-2, a feedback control unit 12a, a feedforward control unit 15a, a second calculation unit 16a, an adjustment amount calculation unit 13a, and an actuator control unit 14. The first calculation unit 11-1 takes in a target buoyancy value, which is a target value of the water volume control system corresponding to a predetermined depth control index and can be specified to an arbitrary value, and a depth adjustment rudder angle command value (δb) output by the depth FB control unit 32-1. The first calculation unit 11-1 subtracts the depth adjustment rudder angle command value (δb) from the buoyancy target value to calculate an error and outputs the calculated error to the buoyancy FB control unit 12-1 of the feedback control unit 12a. The first calculation unit 11-2 takes in a target trim value, which is a target value of the water volume control system corresponding to a predetermined pitch angle control index and can be specified to an arbitrary value, and a pitch angle adjustment rudder angle command value (δr) output by the pitch angle FB control unit 32-2. The first calculation unit 11-2 calculates the error by subtracting the pitch angle adjustment rudder angle command value (δr) from the trim target value, and outputs the calculated error to the trim FB control unit 12-2 of the feedback control unit 12a.

[0052] Here, the value specified as the buoyancy target value is the buoyancy, which represents force, and the unit of the buoyancy target value is, for example, [N]. The value specified as the trim target value is the trim control moment, which represents moment, and the unit of the trim target value is, for example, [N·m]. In contrast, the depth adjustment rudder angle command value (δb) and the pitch angle adjustment rudder angle command value (δr) are angles, and their unit is, for example, [rad]. Therefore, the units of the target values ​​given to each of the first calculation units 11-1 and 11-2 and the feedback values ​​are different. For this reason, the first calculation unit 11-1 converts the depth adjustment rudder angle command value, which is the feedback value, to the unit "N", and the first calculation unit 11-2 converts the pitch angle adjustment rudder angle command value, which is the feedback value, to the unit "N·m", and then performs the subtraction calculation from the target values ​​given to each.

[0053] For example, the force acting on the underwater vehicle 6a in the vertical direction by the depth adjustment rudder can be estimated from the time-series change of the depth adjustment rudder angle command value (δb). In addition, the moment acting on the underwater vehicle 6a in the pitch axis direction by the pitch angle adjustment rudder can be estimated from the time-series change of the pitch angle adjustment rudder angle command value (δr). The first calculation unit 11-1 can take in a series of consecutive depth adjustment rudder angle command values ​​(δb) and convert the estimated force from the acquired series of depth adjustment rudder angle command values ​​(δb) to units of force. The first calculation unit 11-2 can take in a series of consecutive pitch angle adjustment rudder angle command values ​​(δr) and convert the estimated moment from the acquired series of pitch angle adjustment rudder angle command values ​​(δr) to units of moment.

[0054] The feedback control unit 12a comprises a buoyancy FB control unit 12-1 and a trim FB control unit 12-2. Each of the buoyancy FB control unit 12-1 and the trim FB control unit 12-2 is a PID controller that performs calculations corresponding to the transmission element 62 designed in accordance with the "Design Guidelines for Feedback Control Units" described above. However, unlike the control system 100, the control system 100a is configured to feed back two rudder angle command values ​​output by the motion control system control device 3a to the water flow control system control device 1a. Therefore, when designing the control system, the design should be carried out taking into account the differences in configuration between the control system 100 of the first embodiment and the control system 100a of the second embodiment, and the PID controllers applied to each of the buoyancy FB control unit 12-1 and the trim FB control unit 12-2 should be designed accordingly. pt ,T it ,T dt The parameters will be determined. Note that the PID control methods for the buoyancy FB control unit 12-1 and the trim FB control unit 12-2 are designed individually, so each parameter K pt ,T it ,T dt These will be different, but depending on the design, they may coincide.

[0055] The buoyancy FB control unit 12-1 performs PID control calculations on the error output by the first calculation unit 11-1, and sets the up / down command value (F) relative to the buoyancy target value. c The buoyancy control unit 12-1 calculates the calculated vertical command value (F). c The trim FB control unit 12-2 performs a PID control calculation on the error output by the first calculation unit 11-2 and outputs a trim command value (M) relative to the trim target value. c The trim FB control unit 12-2 calculates the calculated trim command value (M). c The output is sent to the second arithmetic unit 16a-2.

[0056] The feedforward control unit 15a corresponds to the feedforward controller 68 designed in accordance with the "Design Guidelines for Feedforward Control Units" described above. Figure 6 is a block diagram showing the configuration of the feedforward control unit 15a according to the second embodiment. As shown in Figure 6, the feedforward control unit 15a comprises a first feedforward control unit 15-1, a second feedforward control unit 15-2, and a third feedforward control unit 15-3. When a state signal relating to a change in the state of the underwater vehicle 6a that affects at least one of the position and attitude of the underwater vehicle 6a is input to the feedforward control unit 15a, it obtains a predicted value of the amount of unbalance occurring in the underwater vehicle 6a by feedforward control.

[0057] Figure 7 is a block diagram showing the configuration of the first feedforward control unit 15-1 according to the second embodiment. In the first feedforward control unit 15-1 shown in Figure 7, when the control system (not shown) for operating the rudder and thrusters of the underwater vehicle 6a is operated and at least one of the forward speed and attitude angle (pitch angle) of the underwater vehicle 6a is changed, a predicted value of the unbalance amount of the underwater vehicle 6a is obtained. The first feedforward control unit 15-1 comprises a first unbalance amount acquisition unit 151a and a first data storage unit 152a. The first unbalance quantity acquisition unit 151a acquires the unbalance quantity based on state change instruction inputs from the control system (not shown) when the control system (not shown) for operating the rudder or thrusters of the underwater vehicle 6a is operated in order to change at least one of the forward speed and attitude angle (pitch angle) of the underwater vehicle 6a. The state change instruction inputs from the control system include the input value for forward speed and the input value for attitude angle. Figure 8 shows an example of correlation data between forward speed and unbalanced weight stored in the first feedforward control unit 15-1 according to the second embodiment. Figure 9 shows an example of correlation data between forward speed and unbalanced moment stored in the first feedforward control unit 15-1 according to the second embodiment. The first data storage unit 152a has pre-stored data, as shown in Figure 8, showing the correlation between forward speed and unbalanced weight for each change in pitch angle, and as shown in Figure 9, showing the correlation between forward speed and unbalanced moment for each change in pitch angle.

[0058] In the first feedforward control unit 15-1, when a forward speed instruction value for changing the forward speed of the underwater vehicle 6a and an attitude angle instruction value for changing the attitude angle are input, the first unbalance amount acquisition unit 151a acquires predicted values ​​of unbalance weight and unbalance moment corresponding to the forward speed instruction value and attitude angle instruction value, based on the data stored in the first data storage unit 152a. The first unbalance amount acquisition unit 151a outputs the acquired predicted value of unbalance weight to the second calculation unit 16a-1. The first unbalance amount acquisition unit 151a outputs the acquired predicted value of unbalance moment to the second calculation unit 16a-2.

[0059] Figure 10 shows an example of correlation data between propeller rotation speed and forward speed stored in the first feedforward control unit 15-1 according to the second embodiment. Furthermore, the first feedforward control unit 15-1 can also receive a propeller rotation speed instruction value for changing the forward speed of the underwater vehicle 6a, instead of a forward speed instruction value for changing the forward speed of the underwater vehicle 6a. In this case, the first data storage unit 152a has data showing the correlation between propeller rotation speed and forward speed pre-stored, as shown in Figure 10. When the propeller rotation speed instruction value is input as a state change instruction input for the underwater vehicle 6a, the first unbalance amount acquisition unit 151a acquires the forward speed corresponding to the propeller rotation speed instruction value based on the data showing the correlation between propeller rotation speed and forward speed stored in the first data storage unit 152a. After this, as described above, the first data storage unit 152a acquires the acquired forward speed and the values ​​of unbalance weight and unbalance moment corresponding to the attitude angle instruction value as predicted values.

[0060] Figure 11 is a block diagram showing the configuration of the second feedforward control unit 15-2 according to the second embodiment. In the second feedforward control unit 15-2 shown in Figure 11, when the depth of the underwater vehicle 6a is changed by operating the control system (not shown) for operating the rudder and thrusters of the underwater vehicle 6a, a predicted value of the unbalanced weight is obtained as the unbalanced amount of the underwater vehicle 6a. The second feedforward control unit 15-2 comprises a second unbalanced amount acquisition unit 151b and a second data storage unit 152b. The second unbalance amount acquisition unit 151b acquires the unbalance weight based on a state change instruction input from the control system (not shown) of the underwater vehicle 6a when the control system (not shown) of the underwater vehicle 6a is operated to change the depth of the underwater vehicle 6a. The state change instruction input from the control system includes the current depth and the depth instruction value. Figure 12 shows an example of data showing the correlation between water temperature, depth, and discharge volume, stored in the second feedforward control unit 15-2 according to the second embodiment. The second data storage unit 152b pre-stores data showing the correlation between water temperature, depth, and displacement, as shown in Figure 12. The density of seawater differs depending on the water temperature and depth. The displacement of the underwater vehicle 6a, which correlates with the buoyancy of the underwater vehicle 6a, differs depending on the density of seawater. The isodisplacement curves in Figure 12 show water temperature and depth where the density of seawater is equal. The second data storage unit 152b also pre-stores a database showing the correlation between the depth and water temperature of the sea area in which the underwater vehicle 6a is navigating. The database showing the correlation between the depth and water temperature of a sea area is constructed, for example, by accumulating depth and water temperature data detected by the detection unit 5 when the underwater vehicle 6a has navigated the sea area in advance. The database showing the correlation between the depth and water temperature of a sea area may be updated sequentially by acquiring depth and water temperature data while the underwater vehicle 6a is navigating.

[0061] In this second feedforward control unit 15-2, when a target depth instruction value for changing the depth of the underwater vehicle 6a is input, the second unequilibrium amount acquisition unit 151b acquires the current depth at that time. The second unequilibrium amount acquisition unit 151b refers to a database in the second data storage unit 152b that shows the correlation between depth and water temperature in the sea area, and acquires the water temperature at the target depth (target water temperature) and the water temperature at the current depth (current water temperature), corresponding to the target depth instruction value and the current depth. Furthermore, the second unequilibrium amount acquisition unit 151b refers to data in the second data storage unit 152b, shown in Figure 12, that shows the correlation between water temperature, depth, and displacement, and acquires the current displacement at the current depth and current water temperature (for example, point D1 in Figure 12), the target depth corresponding to the target depth instruction value, and the target displacement at the target water temperature (for example, point D2 in Figure 12). The second unequilibrium amount acquisition unit 151b calculates the difference between the acquired current discharge amount and the target discharge amount, and acquires the value of the unequilibrium weight as a predicted value when the depth is changed from the current depth to the target depth.

[0062] Figure 13 is a block diagram showing the configuration of the third feedforward control unit 15-3 according to the second embodiment. In the third feedforward control unit 15-3 shown in Figure 13, when the arrangement (distribution) of personnel inside the underwater vehicle 6a is changed, a predicted value of the unequilibrium moment is obtained as the unequilibrium amount of the underwater vehicle 6a. The third feedforward control unit 15-3 comprises a third unequilibrium amount acquisition unit 151c and a third data storage unit 152c. In the underwater vehicle 6a, a change in the arrangement (distribution) of personnel within the underwater vehicle 6a results in a change in the state of the underwater vehicle 6a that affects at least one of its position and attitude. When the arrangement of personnel within the underwater vehicle 6a is changed, the third unbalance quantity acquisition unit 151c receives personnel arrangement information as a state change signal, which indicates the number of personnel to be placed in each of several pre-set areas within the underwater vehicle 6a. The personnel arrangement information is input to the control system via a terminal (not shown) that can receive input from an external source. The personnel arrangement information may also be input by detecting the number of personnel present in each area using, for example, human presence sensors installed at various locations within the underwater vehicle 6a. The third data storage unit 152c has pre-stored the distance from the center of gravity of the underwater vehicle 6a to each area, as well as personnel weight data (for example, the average weight of the personnel).

[0063] In such a third feedforward control unit 15-3, when personnel placement information within the underwater vehicle 6a is input as a state change signal, the third unbalance amount acquisition unit 151c calculates the unbalance moment M based on the previous personnel placement state using the following equation (3). Here, M is the unbalance moment, Wi is the personnel weight in each area, and li is the distance from the center of gravity of the underwater vehicle 6a in each area.

number

[0064] The third unequilibrium quantity acquisition unit 151c acquires the unequilibrium moment M calculated by equation (3) as a predicted value.

[0065] The second calculation unit 16a adds the command value calculated by the feedback control unit 12 and the predicted value acquired by the feedforward control unit 15 and outputs it to the adjustment amount calculation unit 13a. The second calculation unit 16a-1 calculates the up and down command value (F) calculated by the float FB control unit 12-1. c The second calculation unit 16a-2 adds the trim command value (M) calculated by the float FB control unit 12-1 and outputs it to the adjustment amount calculation unit 13a. c The first unequilibrium amount acquisition unit 151a adds the predicted value of the unequilibrium moment obtained by the first unequilibrium amount acquisition unit 151a and outputs the result to the adjustment amount calculation unit 13a.

[0066] The adjustment amount calculation unit 13a executes a calculation formula to calculate the optimal solution obtained in advance by analysis using the Lagrange multiplier method in accordance with the "Design Guidelines for the Adjustment Amount Calculation Unit" described above, that is, a calculation formula to calculate the optimal adjustment amounts V1 to V5 for each of the tanks 22-1 to 22-5. The adjustment amount calculation unit 13a takes the up and down command value (F) output by the buoyancy FB control unit 12-1 as input. c ) and the trim command value (M) output by the trim FB control unit 12-2 c Based on this, the adjustment amount (ΔV1 to ΔV5) for the water volume of each of the tanks 22-1 to 22-5 is calculated. The adjustment amount calculation unit 13a outputs the calculated adjustment amount (ΔV1 to ΔV5) for each of the tanks 22-1 to 22-5 to the actuator control unit 14.

[0067] (An example of a calculation formula for calculating the optimal solution applied to the adjustment amount calculation unit) Here, as an example, we define a motion model for the underwater vehicle 6a that is limited to a linear model relating to depth and pitch angle, and then explain a method for obtaining the calculation formula for the optimal solution applied to the adjustment amount calculation unit 13a using the Lagrange multiplier method. The linear model relating to depth can be expressed as the equation of motion in the following equation (4).

[0068]

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[0069] The names and units of each physical parameter shown in equation (4) are as shown in the table in Figure 14. The "w" with a "·" on the left side of equation (4) is the derivative of the depth velocity, i.e., the depth acceleration, and the depth acceleration is multiplied by the depth axis mass "m z By multiplying by ", we obtain the force acting on the underwater vehicle 6a in the vertical direction, that is, in the Z-axis direction when the pitch axis and roll axis of the underwater vehicle 6a are on the horizontal plane, with the roll axis being the X-axis and the pitch axis being the Y-axis. The first term on the right side of equation (4) is "-D z "w" is the velocity damping term obtained by multiplying the viscous drag coefficient by the depth velocity, and represents the viscous force acting when the underwater vehicle 6a sinks. The second term on the right side of equation (4) is "K δb δb represents the force acting on the underwater vehicle 6a in the vertical direction by the depth adjustment rudder. The third term on the right-hand side of equation (4) is "F d " is a disturbance force acting on the underwater vehicle 6a in the vertical direction due to an external disturbance, indicating an imbalance in the weight of the underwater vehicle 6a. Note that if there is a rudder angle on the depth adjustment rudder under steady conditions, the force due to the rudder angle is considered a static disturbance force, and the force due to the rudder angle is denoted as "F d The fourth term on the right side of equation (4) is "F t (ΔV1, ΔV2, ΔV3, ΔV4, ΔV5) are vertical control forces and represent the buoyancy generated in the vertical direction of the underwater vehicle 6a by tanks 22-1 to 22-5.

[0070] A linear model with respect to the pitch angle can be expressed as the equation of motion in equation (5) below.

[0071]

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[0072] The names and units of the physical parameters shown in equation (5) are as shown in the table in Figure 14. The "q" enclosed by a "·" on the left side of equation (5) is the derivative of the pitch angular velocity, i.e., the pitch angular acceleration, and the pitch angular acceleration is multiplied by the pitch axis moment of inertia J. pBy multiplying by this, we obtain the moment of rotational force acting on the underwater vehicle 6a with respect to the pitch axis of the underwater vehicle 6a. The first term on the right side of equation (5) is "-D p "q" is the velocity damping term obtained by multiplying the viscous drag coefficient by the pitch angular velocity, and it represents the moment of viscous force acting in the direction of the pitch axis of the underwater vehicle 6a when the underwater vehicle 6a rotates around the pitch axis. The second term on the right side of equation (5) is "-K p In θ, "K p " is the restoring moment coefficient, and "θ" is the pitch angle. The underwater vehicle 6a is designed so that when it tilts from a certain state, a moment acts to return it to its original state according to the angle of tilt. Therefore, "-K p "θ" represents the moment of the restoring force acting on the underwater vehicle 6a in the pitch axis direction when the underwater vehicle 6a is tilted at an angle of "θ" in the pitch axis direction.

[0073] The third term on the right-hand side of equation (5) is "K δr δr represents the moment acting on the underwater vehicle 6a in the pitch axis direction by the pitch angle adjustment rudder. The fourth term on the right side of equation (5) is "M d " indicates the moment of the disturbance force acting on the underwater vehicle 6a in the pitch axis direction due to the disturbance. Note that if there is a rudder angle on the pitch angle adjustment rudder in steady state, the moment due to the rudder angle is considered a static disturbance moment, and the moment due to the rudder angle is expressed as "M d The fifth term on the right side of equation (5) is "M t (ΔV1, ΔV2, ΔV3, ΔV4, ΔV5) are trim control moments, representing the buoyancy moments acting on the underwater vehicle 6a in the pitch axis direction by tanks 22-1 to 22-5. In equations (4) and (5), ΔV1, ΔV2, ΔV3, ΔV4, and ΔV5 are adjustment amounts calculated by the adjustment amount calculation unit 13a, indicating the increase or decrease in the amount of water in each of the tanks 22-1, 22-2, 22-3, 22-4, and 22-5, as described above.

[0074] The state conditions that describe the state of the underwater vehicle 6a are defined as constraint conditions in the Lagrange multiplier method. Here, the state conditions that describe the state of the underwater vehicle 6a are those in which the vertical unbalance and the pitch axis unbalance of the underwater vehicle 6a are both set to "0". A vertical unbalance of "0" means that the underwater weight of the underwater vehicle 6a is "0 [kg]" and it is in a state of neutral buoyancy. A pitch axis unbalance of "0" means that the pitch angle of the underwater vehicle 6a is "0 [rad]" and the roll axis of the underwater vehicle 6a is horizontal. Assuming that the underwater vehicle 6a is in an equilibrium state with a constant velocity, the constraint conditions can be expressed as equations (6) and (7) below.

[0075]

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[0076]

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[0077] The first to third terms on the right-hand side of equation (6) represent the up / down command values ​​F output by the buoyancy FB control unit 12-1. c Assume that it is compensated by [N]. Also, the first to fourth terms on the right-hand side of equation (7) are the trim command value M output by the trim FB control unit 12-2. c Assume that compensation is provided by [N·m]. Furthermore, as mentioned above, if there is a rudder angle on the depth adjustment rudder and the pitch angle adjustment rudder in steady state, the force and moment due to the rudder angle present in steady state are given by "F" respectively. d " and "M d In addition to "F", the force and moment due to the rudder angle present in steady state are also "F c " and "M c Assume that it cancels out due to . In this case, the constraints in equations (6) and (7) can be expressed as equations (8) and (9), respectively.

[0078]

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[0079]

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[0080] Here, the buoyancy (F) due to tanks 22-1 to 22-5 t ), and the moment of buoyancy (M t These can be calculated using the following equations (10) and (11), respectively.

[0081]

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[0082]

number

[0083] In equations (10) and (11), ρ is the density of seawater [kg / m³]. 3 ] and g is the acceleration due to gravity [m / s²]. 2 ]. Also, in equation (11), each of l1 to l5 is the distance from the center of gravity of the underwater vehicle 6a to the center of gravity of each of the tanks 22-1 to 22-5.

[0084] By applying equations (10) and (11) to equations (8) and (9), equations (8) and (9) can be transformed into the following equations (12) and (13).

[0085]

number

[0086]

number

[0087] Here, we define the objective function of the Lagrange multiplier method as follows: (14)

[0088]

number

[0089] Equation (14) is an evaluation function that assesses the amount of water moved between tanks 22-1 to 22-5, and represents the adjustment conditions for the water volume in tanks 22-1 to 22-5. Minimizing the evaluation function in equation (14) means minimizing the amount of adjustment for the water volume in tanks 22-1 to 22-5. Minimizing the amount of adjustment for the water volume in tanks 22-1 to 22-5 means minimizing the operating rate of pumps 21P-1 to 21P-7 and minimizing energy consumption.

[0090] Using the constraints in equations (12) and (13), the objective function in equation (14), and the Lagrange multipliers λ1 and λ2, we formulate the Lagrange equation shown in equation (15).

[0091]

number

[0092] The optimal solution to equation (15) can be found by setting the condition that each of the equations obtained by partially differentiating equation (15) with respect to the variables ΔV1 to ΔV5 and the Lagrange multipliers λ1 and λ2 is "0", as shown in equation (16).

[0093]

number

[0094] From equation (16), a system of seven equations can be derived. By eliminating λ1 and λ2 from the system of seven equations, the up / down command value (F) output by the buoyancy FB control unit 12-1 can be obtained. c ) and the trim command value (M) output by the trim FB control unit 12-2 cFrom this, a calculation formula for calculating the optimal solution can be obtained, that is, a calculation formula for calculating the optimal adjustment amounts ΔV1 to ΔV5 for each of the tanks 22-1 to 22-5. The computer that executes the calculation formula for calculating the optimal solution obtained as described above is designated as the adjustment amount calculation unit 13a.

[0095] (Processing by the control system of the second embodiment) The following describes the processing performed by the control system 100a of the second embodiment.

[0096] (Processing by the motion control system) Figure 15 is a flowchart showing the processing flow by the motion control system control device 3a and the rudder control device 4a. Before the processing shown in Figure 15 begins, the motion control system control device 3a is given a target depth value and a target pitch angle value. The detection unit 5a is assumed to repeatedly detect the control amounts of depth and pitch angle at regular intervals. For example, the motion control system control device 3a is equipped with an ON / OFF switch, and when it is turned ON, the processing shown in Figure 15 begins.

[0097] The calculation unit 31-1 takes in the specified depth target value and the depth control amount detected by the detection unit 5a. The calculation unit 31-2 takes in the specified pitch angle target value and the pitch angle control amount detected by the detection unit 5a (step Sa1). The calculation unit 31-1 calculates an error by subtracting the depth control amount from the depth target value and outputs the calculated error to the depth FB control unit 32-1. The depth FB control unit 32-1 takes in the error output by the calculation unit 31-1 and calculates a depth adjustment rudder angle command value (δb) based on the taken-in error. The depth FB control unit 32-1 outputs the calculated depth adjustment rudder angle command value (δb) to the rudder control device 4a (step Sa2-1). The calculation unit 31-2 calculates an error by subtracting the pitch angle control amount from the pitch angle target value and outputs the calculated error to the pitch angle FB control unit 32-2. The pitch angle FB control unit 32-2 takes in the error output by the calculation unit 31-2 and calculates the pitch angle adjustment rudder angle command value (δr) based on the acquired error. The pitch angle FB control unit 32-2 outputs the calculated pitch angle adjustment rudder angle command value (δr) to the rudder control device 4a (step Sa2-2).

[0098] The rudder control device 4a changes the direction of the depth adjustment rudder according to the depth adjustment rudder angle command value (δb) output by the depth FB control unit 32-1. This adjusts the force from the depth adjustment rudder and the disturbance force (F d The combined force of () acts on the underwater vehicle 6a, causing a change in the depth of the underwater vehicle 6a (step Sa3-1). The rudder control device 4a changes the direction of the pitch angle adjustment rudder according to the pitch angle adjustment rudder command value (δr) output by the pitch angle FB control unit 32-2. This combines the moment due to the pitch angle adjustment rudder and the disturbance moment (M d The combined moment of ) acts on the underwater vehicle 6a, causing the pitch angle of the underwater vehicle 6a to change (Step Sa3-2).

[0099] If the ON / OFF switch of the motion control system control device 3a is in the ON state, the control by the motion control system is assumed to be continuing (step Sa4, Yes), and the processing from step Sa1 onwards is carried out. On the other hand, if the ON / OFF switch of the motion control system control device 3a is in the OFF state, the calculation units 31-1, 31-2, the depth FB control unit 32-1, and the pitch angle FB control unit 32-2 stop operating (step Sa4, No), and the processing ends.

[0100] In the process shown in Figure 15, steps Sa2-1 and Sa3-1, and steps Sa2-2 and Sa3-2 are performed in parallel.

[0101] (Processing by water flow control system) Figure 16 is a flowchart showing the processing flow by the water volume control system 1a and the tank system 2. Before the processing in Figure 16 begins, the buoyancy target value and the trim target value are specified to the water volume control system 1a. The detection unit 5a is assumed to repeatedly detect the control amounts of depth and pitch angle at regular intervals. The motion control system 3a and the rudder control unit 4a are assumed to be continuously performing the processing shown in Figure 15 with the motion control system 3a in the ON state. For example, the water volume control system 1a is equipped with an ON / OFF switch, and when it is turned ON, the processing shown in Figure 16 begins.

[0102] The first calculation unit 11-1 receives the specified buoyancy target value and the depth adjustment rudder angle command value (δb) output by the depth FB control unit 32-1. The first calculation unit 11-1 converts the depth adjustment rudder angle command value (δb) to the units of the buoyancy target value, then subtracts the converted depth adjustment rudder angle command value (δb) from the buoyancy target value to calculate the error, and outputs the calculated error to the buoyancy FB control unit 12-1. The first calculation unit 11-2 receives the specified trim target value and the pitch angle adjustment rudder angle command value (δr) output by the pitch angle FB control unit 32-2. The first calculation unit 11-2 converts the pitch angle adjustment rudder angle command value (δr) to the units of the trim target value, then subtracts the converted depth adjustment rudder angle command value (δb) from the trim target value to calculate the error, and outputs the calculated error to the trim FB control unit 12-2 (step Sb1).

[0103] The buoyancy FB control unit 12-1 calculates the upper and lower command value (F) from the error output by the first calculation unit 11-1 using PID control calculation. c The buoyancy control unit 12-1 calculates the calculated vertical command value (F). c ) is output to the second calculation unit 16a (step Sb2-1). The trim FB control unit 12-2 calculates the trim command value (M) from the error output by the first calculation unit 11-2 using PID control calculation. c The trim FB control unit 12-2 calculates the calculated trim command value (M). c ) is output to the second arithmetic unit 16a (step Sb2-2).

[0104] The feedforward control unit 15a checks for the presence or absence of a status signal input based on the status change instruction input from the control system (step Sb3). If no status signal input is found (step Sb3, No), step Sb4 is skipped and the process proceeds to step Sb5. If a status signal input is found (step Sb3, Yes), the feedforward control unit 15a obtains a predicted value of the unbalance amount of the underwater vehicle when a status change occurs, based on the input status signal, and outputs the obtained predicted value to the second calculation unit 16a (step Sb4).

[0105] The second calculation unit 16a adds the command value calculated by the feedback control unit 12a and the predicted value acquired by the feedforward control unit 15a to obtain an upper / lower command value (F c ) and trim command value (M c The adjustment amount calculation unit 13a outputs the upper / lower command value (F c ) and trim command value (M c The adjustment amount calculation unit 13a takes in the acquired upper and lower command values ​​(F c ) and trim command value (M c The adjustment amount calculation unit 13a calculates the adjustment amounts ΔV1 to ΔV5 by performing calculations using an arithmetic formula that calculates the optimal solution, taking the inputs ) and . The adjustment amount calculation unit 13a outputs the calculated adjustment amounts ΔV1 to ΔV5 to the actuator control unit 14 (step Sb5).

[0106] The actuator control unit 14 generates control signals to turn ON or OFF the respective drive means of the actuators 21, namely pumps 21P-1 to 21P-7 and valves 21V-1 to 21V-15, based on the adjustment amounts ΔV1 to ΔV5 output by the adjustment amount calculation unit 13a and the conversion rule data pre-stored in the internal memory area. The actuator control unit 14 outputs each of the generated control signals to the corresponding drive means of the pumps 21P-1 to 21P-7 and valves 21V-1 to 21V-15 (step Sb6).

[0107] When each of the drive mechanisms for pumps 21P-1 to 21P-7 and valves 21V-1 to 21V-15 receives a control signal from the actuator control unit 14 to turn ON or OFF, it starts operating according to the control signal, thereby causing water to be transferred or filled and drained in tanks 22-1 to 22-5 (step Sb7).

[0108] If the ON / OFF switch of the water flow control system control device 1a is in the ON state, the control by the water flow control system is assumed to be continuing (step Sb8, Yes), and the processing from step Sb1 onwards is carried out. On the other hand, if the ON / OFF switch of the water flow control system control device 1a is in the OFF state, the first calculation units 11-1, 11-2, the float FB control unit 12-1, the trim FB control unit 12-2, the adjustment amount calculation unit 13a, and the actuator control unit 14 stop operating (step Sb8, No), and the processing ends.

[0109] In the process shown in Figure 16, steps Sb2-1 and Sb2-2 are performed in parallel.

[0110] (Simulation results) Figures 17 and 18 are graphs showing the simulation results performed using the control system 100a. In the graphs of Figures 17 and 18, the horizontal axis represents elapsed time in seconds, and the time at the left end of the horizontal axis is "0 seconds". Also, in Figures 17 and 18, the time indicated by the vertical dashed line is the same time, and this time is when the water flow control system control device 1a was turned ON, that is, when the water flow control system control device 1a started the process shown in Figure 16. The detection unit 5a starts the process of detecting the control amounts of depth and pitch angle at regular intervals at time "0 seconds". The motion control system control device 3a is turned ON at time "0 seconds" and has started the process shown in Figure 15. In addition, the target depth value indicated by the dashed line of reference numeral 71 in Figure 17(e) and the target pitch angle value indicated by the dashed line of reference numeral 72 in Figure 17(f) are specified for the motion control system control device 3a.

[0111] Note that in Figures 17(c), (d), and (f), values ​​obtained in units of [rad] are shown converted to units of [deg]. Also, in the graphs in Figures 17(a), (b), (g), and (h), the units of [tonf (ton-force)] and "tonf·m" are shown by converting values ​​obtained in units of [N] and [N·m] to [tonf] and [tonf·m].

[0112] The graphs in Figures 18(a), (b), (c), (d), and (e) show the water volume in tanks 22-1, 22-2, 22-3, 22-4, and 22-5 as a percentage, and it is assumed that at time "0 seconds", each of tanks 22-1 to 22-5 contains water at the same ratio.

[0113] As shown in the graphs in Figures 17(a) and (b), a constant disturbance force (F) is exerted on the underwater vehicle 6a at a time slightly after time 0 [seconds]. d ) and a constant disturbance moment (M d ) is added, which disrupts the weight balance of the underwater vehicle 6a. The depth FB control unit 32-1 and pitch angle FB control unit 32-2 of the motion control system control device 3a, and the rudder control device 4a control change the depth adjustment rudder angle and the pitch angle adjustment rudder angle as shown in the graphs in Figures 17(c) and (d). The graphs in Figures 17(e) and (f) show the changes in depth and pitch angle of the underwater vehicle 6a as detected by the detection unit 5a, respectively. As shown in the graph in Figure 17(e), the disturbance force (F d When the disturbance moment (M) is added, the underwater vehicle 6a sinks and its depth increases, and thereafter a constant depth is maintained by the control of the depth FB control unit 32-1. However, the control by the depth FB control unit 32-1 does not converge to the target depth value shown by the dashed line labeled 71 in Figure 17(e). In contrast, as shown in the graph of Figure 17(f), the disturbance moment (M) d When this is added, the underwater vehicle 6a tilts around the pitch axis, causing the pitch angle to increase. However, the pitch angle is then controlled by the pitch angle FB control unit 32-2 to converge to the target pitch angle shown by the dashed line of reference numeral 72.

[0114] At the time indicated by the vertical dashed line, the water volume control system control device 1a starts the process shown in Figure 16. In the water volume control system control device 1a, the buoyancy target value indicated by the dashed line labeled 73 in the graph of Figure 17(g) is specified, and the trim target value indicated by the dashed line labeled 74 in the graph of Figure 17(h) is specified. As control by the water volume control system control device 1a begins, the water volume in each of the tanks 22-1 to 22-5 gradually decreases according to the adjustment amounts ΔV1 to ΔV5 for each of the tanks 22-1 to 22-5 calculated by the adjustment amount calculation unit 13a, as shown in the graph of Figure 18, and the amount of water stored in each of the tanks 22-1 to 22-5 converges to a constant amount without overshooting. The depth of the underwater vehicle 6a detected by the detection unit 5a converges to the depth target value indicated by the dashed line labeled 71 without disturbance from the time indicated by the vertical dashed line, as shown in the graph of Figure 17(e). As shown in the graph in Figure 17(f), the pitch angle of the underwater vehicle 6a detected by the detection unit 5a undergoes some fluctuations after the time indicated by the vertical dashed line, but ultimately converges to the target pitch angle value indicated by the dashed line of reference numeral 72. Also, as shown in the graphs in Figures 17(c) and (d), after the time indicated by the vertical dashed line, the depth adjustment rudder angle and the pitch angle adjustment rudder angle converge to a neutral state where no rudder control is being performed. Furthermore, as shown in the graphs in Figures 17(g) and (h), the vertical buoyancy of the underwater vehicle 6a converges to the buoyancy target value indicated by the dashed line of reference numeral 73, and the trim control moment of the underwater vehicle 6a also converges to the trim target value indicated by the dashed line of reference numeral 74.

[0115] With the configuration of the second embodiment described above, the control system 100a enables stable automatic control, that is, it compensates for the response delay caused by the capacity constraints of the actuator 21, suppresses interference between the control bandwidth of the water volume control system and the control bandwidth of the existing control system, which is the motion control system, and calculates the optimal amount of water volume adjustment for each of the multiple tanks 22-1 to 22-5 so that the entire control system, including the motion control system, converges in parallel toward the buoyancy target value and the trim target value, and then performs water transfer and filling / draining to the tanks 22-1 to 22-5. In other words, it becomes possible to optimize the water volume of multiple tanks so that the control system of the underwater vehicle 6a converges toward the target value, while taking into account the capacity constraints of the actuator 21 and coordinating with the existing control system.

[0116] Furthermore, the target values ​​for the water flow control system and the motion control system in the control system 100 of the first embodiment described above, as well as the target values ​​for buoyancy, trim, depth, and pitch angle in the control system 100a of the second embodiment, may be values ​​pre-written in the internal memory areas of the water flow control system control devices 1, 1a and motion control system control devices 3, 3a, or a user may operate a setting device installed on land to transmit these target values ​​to the control systems 100, 100a via acoustic communication or wired cable communication. Similarly, the ON / OFF states of the water flow control system control device 1a and the motion control system control device 3a in the control system 100a may also be switched by a user operating a setting device installed on land via acoustic communication or wired cable communication.

[0117] In the first and second embodiments described above, the underwater vehicle 6, 6a is, for example, a manned underwater vehicle on which a person is riding, but it may also be an unmanned underwater vehicle that autonomously navigates underwater.

[0118] Furthermore, in the second embodiment described above, the pitch angle was exemplified as the amount of change indicating the change in attitude due to a change in the state of the underwater vehicle 6a. However, the amount of change indicating the change in attitude due to a change in the state of the underwater vehicle 6a may also be the roll angle, or both the pitch angle and the roll angle.

[0119] Furthermore, in the second embodiment described above, the feedforward control unit 15a is configured to include a first feedforward control unit 15-1, a second feedforward control unit 15-2, and a third feedforward control unit 15-3, but it is not limited to this configuration. The feedforward control unit 15a may be configured to include only one or only two of the first feedforward control unit 15-1, the second feedforward control unit 15-2, and the third feedforward control unit 15-3.

[0120] In the control system 100a of the second embodiment, the rudder angle command value calculated by the motion control system control device 3a is fed back to the water volume control system control device 1a as a feedback value. In contrast, similar to the control system 100 of the first embodiment, the control system 100a may also be configured such that the depth control amount detected by the detection unit 5a is fed back to the first calculation unit 11-1 as a feedback value, and the pitch angle control amount detected by the detection unit 5a is fed back to the first calculation unit 11-2 as a feedback value. Furthermore, generally, underwater vehicles 6, 6a are equipped with a pitch angle adjustment rudder, but may not be equipped with a depth adjustment rudder. In such cases, the depth control amount detected by the detection unit 5a is fed back to the first calculation unit 11-1 as a feedback value, and the pitch angle adjustment rudder angle command value (δr) calculated by the pitch angle FB control unit 32-2 is fed back to the first calculation unit 11-2 as a feedback value.

[0121] In this case, if the units of the given feedback value and the buoyancy target value do not match, the first calculation unit 11-1 will convert the given feedback value to the units of the buoyancy target value and then subtract the converted feedback value from the buoyancy target value. Similarly, if the units of the given feedback value and the trim target value do not match, the first calculation unit 11-2 will convert the given feedback value to the units of the trim target value and then subtract the converted feedback value from the trim target value. For example, if the feedback value is a depth control variable, the force acting on the underwater vehicle 6a in the vertical direction can be estimated from the time-series change in depth. The first calculation unit 11-1 can take in multiple consecutive depth control variables output by the detection unit 5a in a time series and calculate the estimated force from the multiple depth control variables taken in, thereby converting to force units. Also, if the feedback value is a pitch angle control variable, the moment acting on the underwater vehicle 6a in the pitch axis direction can be estimated from the time-series change in pitch angle. The first calculation unit 11-2 can take in a series of control amounts for multiple pitch angles that are consecutive in time, output by the detection unit 5a, and calculate an estimated moment from the acquired control amounts for multiple pitch angles, thereby converting it to a unit of moment.

[0122] In the control system 100a of the second embodiment, the feedback control unit 12a includes two functional units, a buoyancy FB control unit 12-1 and a trim FB control unit 12-2, but it may also include only one of them.

[0123] In the control system 100a of the second embodiment, the feedback control unit 12a may further include a functional unit corresponding to a roll angle control index. In this case, the motion control system control device 3a may also include a functional unit corresponding to a roll angle control index, and the command value output by the functional unit may be fed back as a feedback value to the functional unit corresponding to the roll angle control index provided by the feedback control unit 12a. Alternatively, the roll angle control amount detected by the detection unit 5a may be fed back as a feedback value to the functional unit corresponding to the roll angle control index provided by the feedback control unit 12a.

[0124] In the control system 100a of the second embodiment described above, the rudder control device 4a may be replaced with a control device that controls the thrusters that adjust the depth and pitch angle. In this case, the depth FB control unit 32-1 calculates a command value for the thruster that adjusts the depth and outputs the calculated command value to the control device that controls the thruster and the first calculation unit 11-1. Similarly, the pitch angle FB control unit 32-2 calculates a command value for the thruster that adjusts the pitch angle and outputs the calculated command value to the control device that controls the thruster and the first calculation unit 11-2. Alternatively, the control system 100a may include both the rudder control device 4a and a control device that controls the thrusters.

[0125] As shown in Figure 3 of the first embodiment above, instead of the PID control method, the transmission element 62 may be replaced with a feedback control method such as I-PD control or PI-PD control, or a feedback control method that combines stabilization techniques such as nonlinear compensation or non-interference control. In this case, the feedback control unit 12 of the first embodiment and the float FB control unit 12-1 and trim FB control unit 12-2 of the second embodiment will perform calculations corresponding to the feedback control method that replaces the PID control method.

[0126] In the first and second embodiments described above, the calculation formulas for calculating the optimal solution performed by the adjustment amount calculation units 13 and 13a are obtained using the Lagrange multiplier method. However, other optimization methods may be applied to obtain the calculation formulas for calculating the optimal solution. Furthermore, if the processing power of the computer applied to the adjustment amount calculation units 13 and 13a is high, an optimization method may be used that directly calculates the optimal water volume adjustment amount for each of the multiple tanks 22-1 to 22-5 without obtaining a calculation formula for calculating the optimal solution by performing sequential optimization calculations based on the adjustment conditions and state conditions.

[0127] Figure 19 shows an example of the hardware configuration of a water volume control system control device 1,1a and a motion control system control device 3,3a according to one embodiment. The computer 90 includes a CPU 91, main memory 92, auxiliary memory 93, input / output interface 94, and communication interface 95. The water volume control system control device 1,1a and the motion control system control device 3,3a described above are implemented in the computer 90. The functions described above are stored in the auxiliary memory 93 in the form of a program. The CPU 91 reads the program from the auxiliary memory 93, expands it in the main memory 92, and executes the above processing according to the program. The CPU 91 also allocates a storage area in the main memory 92 according to the program. The CPU 91 also allocates a storage area in the auxiliary memory 93 to store the data being processed according to the program.

[0128] Furthermore, a program to implement all or part of the functions of the water volume control system control devices 1,1a and the motion control system control devices 3,3a may be recorded on a computer-readable recording medium, and the program recorded on this recording medium may be loaded into a computer system and executed to perform processing by each functional unit. Here, "computer system" includes hardware such as the OS and peripheral devices. Also, if a WWW system is used, "computer system" also includes the homepage provisioning environment (or display environment). Furthermore, "computer-readable recording medium" refers to portable media such as CDs, DVDs, USBs, and storage devices such as hard disks built into the computer system. Furthermore, if this program is distributed to computer 90 via a communication line, computer 90 that receives the distribution may load the program into main memory 92 and execute the above processing. Moreover, the above program may be for implementing only a part of the functions described above, and may also be for implementing the above functions in combination with programs already recorded in the computer system.

[0129] As described above, several embodiments relating to this disclosure have been explained, but all of these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be carried out in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims and their equivalents.

[0130] <Note> The water volume control system control devices 1, 1a, control systems 100, 100a, water volume control method, and program described in each embodiment can be understood, for example, as follows.

[0131] (1) The water volume control system control devices 1, 1a according to the first embodiment include motion control devices 4, 4a that control the motion of the underwater vehicles 6, 6a, motion control system control devices 3, 3a that calculate command values ​​for the motion control devices 4, 4a based on the motion control system target value and the control amount detected from the underwater vehicles 6, 6a, and the water volume control system control devices 1, 1a that control to increase or decrease the water volume in each of the tanks 22 of the underwater vehicles 6, 6a, which have a plurality of tanks 22 and actuators 21 that adjust the water volume in each of the tanks 22, and the water volume control system control devices 1, 1a that take the water volume control system target value and a feedback value as inputs and calculate the command value for the water volume control system target value by calculation using a feedback control method that compensates for the response delay of the actuators 21 and suppresses interference with the control band of the motion control system control devices 3, 3a The system includes back control units 12 and 12a, feedforward control units 15 and 15a that receive a state signal relating to a change in the state of the underwater vehicles 6 and 6a that affects at least one of the position and attitude of the underwater vehicles 6 and 6a as input, and based on the state signal, acquire a predicted value of an unbalance amount including at least one of the unbalance weight and unbalance moment of the underwater vehicles 6 and 6a when the change in state occurs, and adjustment amount calculation units 13 and 13a that receive the command value calculated by the feedback control units 12 and 12a and the predicted value acquired by the feedforward control units 15 and 15a as input, and calculate an adjustment amount indicating an increase or decrease in the amount of water for each of the tanks 22 by an optimization method that is based on adjustment conditions relating to the amount of water in a plurality of tanks 22 and state conditions indicating the state of the underwater vehicles 6 and 6a.

[0132] (2) The water volume control system control devices 1, 1a according to the second embodiment are the water volume control system control devices 1, 1a of (1), wherein the state signals relating to the state changes of the underwater vehicles 6, 6a are generated based on state change instruction inputs from the control systems of the underwater vehicles 6, 6a.

[0133] (3) The water volume control system control devices 1, 1a according to the third embodiment are the water volume control system control devices 1, 1a of (2), wherein the state change of the underwater vehicles 6, 6a includes a change in at least one of the forward speed of the underwater vehicles 6, 6a and the attitude angle of the underwater vehicles 6, 6a. Attitude angles include pitch angle and roll angle.

[0134] (4) The water volume control system control devices 1, 1a according to the fourth embodiment are the water volume control system control devices 1, 1a of (2) or (3), wherein the state change of the underwater cruising bodies 6, 6a includes a change in the amount of discharge obtained based on the change in the depth of the underwater cruising bodies 6, 6a in the water and the change in water temperature in accordance with the change in depth.

[0135] (5) The water volume control system control devices 1, 1a according to the fifth embodiment are any one of the water volume control system control devices 1, 1a of (2) to (4), wherein the state change of the underwater vehicles 6, 6a includes the arrangement of the crew members on board the underwater vehicles 6, 6a within the underwater vehicles 6, 6a.

[0136] (6) The control systems 100, 100a according to the sixth embodiment include motion control devices 4, 4a that control the motion of the underwater vehicles 6, 6a, motion control system control devices 3, 3a that calculate command values ​​for the motion control devices 4, 4a based on the motion control system target value and the control amount detected from the underwater vehicles 6, 6a, a plurality of tanks 22 provided in the underwater vehicles 6, 6a, actuators 21 that adjust the amount of water in each of the tanks 22, and water volume control system control devices 1, 1a, wherein the water volume control system control devices 1, 1a take the water volume control system target value and a feedback value as input, and calculate the command value for the water volume control system target value by a feedback control method that compensates for the response delay of the actuator 21 and suppresses interference with the control band of the motion control system control devices 3, 3a The system includes: a feedback control unit 12, 12a that calculates; a feedforward control unit 15, 15a that receives a state signal relating to a change in the state of the underwater vehicles 6, 6a that affects at least one of the position and attitude of the underwater vehicles 6, 6a as input, and based on the state signal, obtains a predicted value of an unbalance amount including at least one of the unbalance weight and unbalance moment of the underwater vehicles 6, 6a when the change in state occurs; and an adjustment amount calculation unit 13, 13a that receives the command value calculated by the feedback control unit 12, 12a and the predicted value obtained by the feedforward control unit 15, 15a as input, and calculates an adjustment amount indicating an increase or decrease in the amount of water for each of the tanks 22 by an optimization method that is based on adjustment conditions relating to the amount of water in a plurality of tanks 22 and state conditions indicating the state of the underwater vehicles 6, 6a.

[0137] (7) A water volume control method according to the seventh embodiment is a water volume control method for an underwater vehicle 6, 6a having motion control devices 4, 4a that control the motion of the underwater vehicle 6, 6a, motion control system control devices 3, 3a that calculate command values ​​for the motion control devices 4, 4a based on a motion control system target value and a control amount detected from the underwater vehicle 6, 6a, a plurality of tanks 22 and actuators 21 that adjust the water volume of each of the tanks 22, wherein the method uses a feedback control system that takes a water volume control system target value and a feedback value as inputs, compensates for the response delay of the actuators 21 and suppresses interference with the control band of the motion control system control devices 3, 3a. A command value is calculated for the target value of the water volume control system by calculation. A state signal relating to a change in the state of the underwater vehicles 6, 6a that affects at least one of the position and attitude of the underwater vehicles 6, 6a is taken as input. Based on the state signal, a predicted value of the unbalance amount, including at least one of the unbalance weight and unbalance moment of the underwater vehicles 6, 6a when the change in state occurs, is obtained. The calculated command value and the obtained predicted value are taken as input, and an adjustment amount indicating an increase or decrease in the water volume for each of the tanks 22 is calculated by an optimization method that is based on adjustment conditions relating to the water volume of the multiple tanks 22 and state conditions indicating the state of the underwater vehicles 6, 6a.

[0138] (8) The program according to the eighth aspect is a program that takes a water volume control system target value and a feedback value as input to a computer provided in the underwater navigating bodies 6, 6a, which has a motion control device 4, 4a that controls the motion of the underwater navigating bodies 6, 6a, motion control system control devices 3, 3a that calculate command values ​​for the motion control device 4, 4a based on a motion control system target value and a control amount detected from the underwater navigating bodies 6, 6a, and a plurality of tanks 22 and an actuator 21 that adjusts the water volume of each of the tanks 22, and calculates the water volume control by a feedback control method that compensates for the response delay of the actuator 21 and suppresses interference with the control band of the motion control system control devices 3, 3a. The system is configured to execute the following steps: a procedure for calculating a command value relative to a target value; a procedure for taking a state signal relating to a change in the state of the underwater vehicles 6, 6a that affects at least one of the position and attitude of the underwater vehicles 6, 6a as input, and based on the state signal, obtaining a predicted value of an unbalance amount including at least one of the unbalance weight and unbalance moment of the underwater vehicles 6, 6a when the change in state occurs; and a procedure for taking the calculated command value and the obtained predicted value as input, and using an optimization method that is conditional on adjustment conditions relating to the water volume of a plurality of tanks 22 and state conditions indicating the state of the underwater vehicles 6, 6a, to calculate an adjustment amount indicating an increase or decrease in the water volume for each of the tanks 22. [Explanation of Symbols]

[0139] 1, 1a...Water volume control system control device 2... Tank system 3, 3a... Motion control system control device 4…Motion control device 4a... Rudder control device (motion control device) 5, 5a...Detection unit 6, 6a...Underwater vehicle 7…Adder 8…Adder 11, 11-1, 11-2...first calculation section 12, 12a... Feedback control unit 12-1…Buoyancy FB Control Unit 12-2…Trim FB Control Unit 13, 13a...adjustment amount calculation section 14…Actuator control unit 15, 15a... Feedforward control unit 15-1…First Feedforward Control Unit 15-2…Second Feedforward Control Unit 15-3…Third Feedforward Control Unit 16, 16a, 16a-1, 16a-2...second calculation section 21… Actuator 21P-1, 21P-3, 21P-6… pumps 21V-1, 21V-3, 21V-11… bulbs 22, 22-1, 22-2, 22-3, 22-5… Tanks 31-1, 31-2...Arithmetic section 32-1…Depth FB Control Unit 32-2…Pitch Angle FB Control Unit 60... Addition point 61...Water volume control system 62, 63… Communication elements 64... Addition point 65...Controlled object 66... ​​Addition point 67…Motor control system 68…Feedforward controller 69... Addition point 90... Computer 91…CPU 92…Main memory 93…Auxiliary storage device 94… Input / Output Interface 95…Communication Interface 100... Control System 100a... Control system 151a...first unbalance amount acquisition section 151b...Second unbalance amount acquisition section 151c…Third unbalance amount acquisition part 152a...First data storage unit 152b...Second data storage unit 152c...Third data storage unit

Claims

1. A water volume control system control that controls the amount of water in each of the tanks of an underwater vehicle, comprising: a motion control device that controls the motion of an underwater vehicle; a motion control system control device that calculates a command value for the motion control device based on a motion control system target value and a control amount detected from the underwater vehicle; and a plurality of tanks and an actuator that adjusts the amount of water in each of the tanks, wherein the water volume control system control device controls the amount of water in each of the tanks of the underwater vehicle, A feedback control unit calculates a command value for the target value of the water flow control system by taking the target value of the water flow control system and a feedback value as inputs, and by performing calculations using a feedback control method that compensates for the response delay of the actuator and suppresses interference with the control band of the motion control system control device, A feedforward control unit receives a state signal relating to a change in the state of the underwater vehicle that affects at least one of the position and attitude of the underwater vehicle, and based on the state signal, obtains a predicted value of an unbalance amount including at least one of the unbalance weight and unbalance moment of the underwater vehicle when the change in state occurs. An adjustment amount calculation unit takes the command value calculated by the feedback control unit and the predicted value acquired by the feedforward control unit as inputs and calculates an adjustment amount indicating an increase or decrease in the water volume for each of the tanks by an optimization method that takes as conditions adjustment conditions for the water volume of a plurality of tanks and state conditions indicating the state of the underwater vehicle as conditions, A water volume control system equipped with a water volume control device.

2. The state signal relating to the state change of the underwater vehicle is, This is generated based on state change instruction input from the control system of the underwater vehicle. The water volume control system control device according to claim 1.

3. The state change of the aforementioned underwater vehicle is, This includes the change in at least one of the forward speed of the underwater vehicle and the attitude angle of the underwater vehicle, The water volume control system control device according to claim 2.

4. The state change of the aforementioned underwater vehicle is, This includes the change in displacement obtained based on the change in depth of the underwater vehicle and the change in water temperature in accordance with the change in depth, The water volume control system control device according to claim 2 or 3.

5. The state change of the aforementioned underwater vehicle is, This includes the arrangement of the crew members aboard the underwater vehicle within the underwater vehicle, The water volume control system control device according to claim 2 or 3.

6. A motion control device that controls the movement of an underwater vehicle, A motion control system control device that calculates command values ​​for the motion control device based on the motion control system target value and the control amount detected from the underwater vehicle, Multiple tanks provided in the aforementioned underwater vehicle, An actuator for adjusting the water volume in each of the aforementioned tanks, A control system comprising a water volume control system control device, The water volume control system control device is A feedback control unit calculates a command value for the target value of the water flow control system by taking the target value of the water flow control system and a feedback value as inputs, and by performing calculations using a feedback control method that compensates for the response delay of the actuator and suppresses interference with the control band of the motion control system control device, A feedforward control unit receives a state signal relating to a change in the state of the underwater vehicle that affects at least one of the position and attitude of the underwater vehicle, and based on the state signal, obtains a predicted value of an unbalance amount including at least one of the unbalance weight and unbalance moment of the underwater vehicle when the change in state occurs. An adjustment amount calculation unit takes the command value calculated by the feedback control unit and the predicted value acquired by the feedforward control unit as inputs and calculates an adjustment amount indicating an increase or decrease in the water volume for each of the tanks by an optimization method that takes as conditions adjustment conditions for the water volume of a plurality of tanks and state conditions indicating the state of the underwater vehicle as conditions, A control system equipped with the following features.

7. A method for controlling the water volume in an underwater vehicle, comprising: a motion control device for controlling the motion of the underwater vehicle; a motion control system control device for calculating a command value for the motion control device based on a target value of the motion control system and a control amount detected from the underwater vehicle; a plurality of tanks; and an actuator for adjusting the water volume in each of the tanks, wherein The command value for the target value of the water flow control system is calculated by a feedback control method that takes the target value of the water flow control system and the feedback value as inputs, compensates for the response delay of the actuator, and suppresses interference with the control band of the motion control system control device. A state signal relating to a change in the state of the underwater vehicle, which affects at least one of the position and attitude of the underwater vehicle, is taken as input, and based on the state signal, a predicted value of the unequilibrium amount, including at least one of the unequilibrium weight and unequilibrium moment of the underwater vehicle when the change in state occurs, is obtained. The calculated command value and the acquired predicted value are used as inputs, and an optimization method is used, which takes as conditions adjustment conditions for the water volume of multiple tanks and state conditions indicating the state of the underwater vehicle, to calculate an adjustment amount indicating the increase or decrease in the water volume for each of the tanks. Water volume control method.

8. A computer provided by the underwater vehicle, which includes a motion control device for controlling the movement of the underwater vehicle, a motion control system control device that calculates command values ​​for the motion control device based on a target value of the motion control system and a control amount detected from the underwater vehicle, and a plurality of tanks and an actuator for adjusting the amount of water in each of the tanks, A procedure for calculating a command value for the target value of the water flow control system by taking the target value of the water flow control system and a feedback value as inputs, compensating for the response delay of the actuator, and suppressing interference with the control bandwidth of the motion control system control device, using a feedback control method. A procedure for obtaining a predicted value of an unbalance quantity, including at least one of the unbalance weight and unbalance moment of the underwater vehicle when the change in state of the underwater vehicle occurs, by inputting a state signal relating to a change in the state of the underwater vehicle that affects at least one of the position and attitude of the underwater vehicle, based on the state signal. A procedure for calculating an adjustment amount indicating an increase or decrease in the water volume for each of the tanks by taking the calculated command value and the acquired predicted value as inputs, and using an optimization method that takes as conditions adjustment conditions for the water volume of multiple tanks and state conditions indicating the state of the underwater vehicle as conditions, A program to execute.

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