JP7653840B2 - Water volume control device, control system, water volume control method, and program - Google Patents

Description

This disclosure relates to a water volume control device, a control system, a water volume control method, and a program.

For example, Patent Document 1 shows an underwater vehicle modularized into multiple cylindrical pressure-resistant containers. Some modules are equipped with tanks for storing water, called ballast tanks, inside the pressure-resistant containers. For example, by adjusting the amount of water in the multiple tanks by transferring water or filling and draining it, the vertical buoyancy 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 the water, putting the underwater vehicle into a neutral buoyancy state where it neither floats nor sinks. The trim of the underwater vehicle can also be controlled by changing the balance of the amount of water in the tanks at the bow and stern of the underwater vehicle.

Patent No. 5166819

However, the underwater vehicle described in Patent Document 1 does not specifically disclose how to adjust the transfer of water and the filling and draining of water into and from multiple tanks in order to control buoyancy and trim. Furthermore, in manned underwater vehicles, humans transfer water into and fill and drain water into and from multiple tanks, taking into account the depth, attitude, and other conditions of the underwater vehicle. Therefore, there has been no concept to date of transferring water into and filling and draining water into and from multiple tanks using some kind of automatic control means without human intervention when controlling buoyancy and trim.

The number of combinations of procedures for transferring water to and filling and discharging water from the multiple tanks provided in the underwater vehicle is enormous. Therefore, the control of transferring water to and filling and discharging water from the multiple tanks can be considered as the control of the control object of a redundant multi-input system. In the case of human operation, many input operations are performed, for example, calculation of the adjustment amount to optimize the amount of water in the multiple tanks, coordination with the existing control system that controls the rudder and thrusters, setting of waiting time considering response delays caused by capacity constraints due to the performance of flow rate and response time of actuators such as pumps and valves, and minimizing the adjustment time required to adjust the amount of water in the tanks. In order to realize these many input operations by automatic control means, design guidelines are required to set each of the things that humans consider when performing many input operations as a problem and design automatic control means that solves the set problems, but there is a problem that such design guidelines have not been established.

The present disclosure has been made in consideration of these problems, and aims to provide a water volume control system control device, control system, water volume control method, and program that optimizes the water volume 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 actuators and coordinating with existing control systems.

In order to solve the above problem, according to one aspect of the present disclosure, a water volume control system control device 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 the amount of water in each of the tanks of the underwater vehicle, the water volume control system control device having a plurality of tanks and an actuator that adjusts the amount of water in each of the tanks, and includes a feedback control unit that receives as input a water volume control system target value and a feedback value, and calculates a command value for the water volume control system target value by calculation using a feedback control method that compensates for response delays of the actuators and suppresses interference with the control bandwidth of the motion control system control device, and an adjustment amount calculation unit that receives as input the command value calculated by the feedback control unit, and calculates an adjustment amount indicating an increase or decrease in the amount of water in each of the tanks by an optimization method that is conditional on adjustment conditions related to the water volumes of the plurality of tanks and state conditions indicating the state of the underwater vehicle.

According to one aspect of the present disclosure, a control system 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, a plurality of tanks provided on the underwater vehicle, and an actuator and a water volume control system control device that adjust the water volume of each of the tanks. The water volume control system control device includes a feedback control unit that receives 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 response delays of the actuators and suppresses interference with the control bandwidth of the motion control system control device, and an adjustment amount calculation unit that receives an input of the command value calculated by the feedback control unit, 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 based on adjustment conditions related to the water volumes of the plurality of tanks and state conditions indicating the state of the underwater vehicle.

According to one aspect of the present disclosure, a water volume control method for 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 motion control system target value and a control amount detected from the underwater vehicle, multiple tanks, and an actuator that adjusts the water volume of each of the tanks, calculates a command value for the water volume control system target value by calculation using a feedback control method that uses a water volume control system target value and a feedback value as input, compensates for response delays of the actuators, and suppresses interference with the control bandwidth of the motion control system control device, and calculates an adjustment amount indicating an increase or decrease in the water volume for each of the tanks by an optimization method that uses the calculated command value as input and has adjustment conditions related to the water volumes of the multiple tanks and state conditions indicating the state of the underwater vehicle as conditions.

According to one aspect of the present disclosure, the program causes a computer included in the underwater vehicle, which has 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 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 water volume of each of the tanks, to execute the following steps: inputting a water volume control system target value and a feedback value, and calculating a command value for the water volume control system target value by calculation using a feedback control method that compensates for response delays of the actuators and suppresses interference with the control bandwidth of the motion control system control device; and inputting the calculated command value and calculating an adjustment amount indicating an increase or decrease in the water volume for each of the tanks by an optimization method that is subject to adjustment conditions related to the water volumes of the plurality of tanks and state conditions indicating the state of the underwater vehicle.

The water volume control system control device, control system, water volume control method, and program disclosed herein make it possible to optimize the water volume 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 actuators and coordinating with an existing control system.

2 is a block diagram showing the configuration of a control system according to the first embodiment and the relationship between forces and moments acting on the underwater vehicle. FIG. 1 is a block diagram showing a configuration of a tank system according to a first embodiment. FIG. FIG. 2 is a block diagram showing a control system of the control system according to the first embodiment. 5 is a diagram illustrating a procedure for obtaining an arithmetic expression for calculating an optimal solution to be applied to an adjustment amount calculation unit of the first embodiment. FIG. FIG. 11 is a block diagram showing the configuration of a control system according to a second embodiment and the relationship between forces and moments acting on an underwater vehicle. FIG. 11 is a diagram showing physical parameters and units included in a mathematical expression used in the second embodiment. FIG. 11 is a diagram showing a processing flow by a motion control system control device and a rudder control device of the second embodiment. FIG. 11 is a diagram showing a process flow by the water volume control device and the tank system of the second embodiment. FIG. 11 is a graph showing a simulation result using the control system according to the second embodiment (part 1). FIG. 13 is a graph showing a simulation result (part 2) using the control system according to the second embodiment. FIG. 2 is a diagram illustrating an example of a hardware configuration of a control system according to the first and second embodiments.

First Embodiment
Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. If we reorganize the issues that humans consider when performing the above-mentioned many input operations as issues for realizing the automatic control means, it is necessary to solve three issues: (issue 1) to compensate for response delays caused by the capacity constraints of the actuators, (issue 2) to suppress interference between the control band of the water volume control system that controls the water volume of multiple tanks and the control band of the motion control system in order to cooperate with the existing control system, which is the motion control system, and (issue 3) to calculate 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 target value specified when controlling the float or trim. Hereinafter, with reference to the control system 100 of the first embodiment, a design guideline for an automatic control system for solving the three issues will be described.

(Control System of the First Embodiment)
FIG. 1 is a block diagram showing an example of the configuration of a control system 100 according to a first embodiment, and the relationship between the forces and moments acting on an underwater vehicle 6 by the control of the control system 100. Here, the underwater vehicle 6 is, for example, an unmanned underwater vehicle such as a UUV (Unmanned Underwater Vehicle) that autonomously navigates underwater. The control system 100 includes 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. Note that FIG. 1 is a block diagram including the underwater vehicle 6 as a structure in order to show the relationship of the entire control system, but in reality, the control system 100 is a system provided in the underwater vehicle 6. In addition, in FIG. 1, solid lines indicate electrical connections, and dashed lines indicate forces and moments acting on the underwater vehicle 6.

The tank system 2 is the object of control by the water volume control device 1, and includes an actuator 21 and a tank 22. FIG. 2 is a block diagram showing a detailed configuration of the tank system 2. The tank 22 is a so-called ballast tank, and includes, for example, five tanks 22-1 to 22-5 as shown in FIG. 2. Tank 22-1 is, for example, a tank located at the bow of the underwater vehicle 6, and tank 22-5 is, for example, a tank located at the stern of the underwater vehicle 6. Tanks 22-2 to 22-4 are tanks located between tanks 22-1 and 22-5, for example, near the center of gravity of the underwater vehicle 6.

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, and when water is discharged from each of the tanks 22-1 to 22-5, buoyancy is generated in the underwater vehicle 6, causing the underwater vehicle 6 to surface. In addition, the amount of water in each of the tanks 22-1 to 22-5 can be adjusted by transferring water stored in one of the tanks 22-1 to 22-5 to another tank 22-1 to 22-5.

In this way, by adjusting the amount of water stored in the tanks 22-1 to 22-5, for example, the direction of movement of the underwater vehicle 6 up and down in the water can be adjusted as shown by the arrow 51, and the depth, which is the distance from the water surface, can be changed arbitrarily. In addition, by making the density of the underwater vehicle 6 equal to the density of the water, the underwater vehicle 6 can be brought into a neutral buoyancy state in which it neither floats nor sinks, that is, its depth is a constant value. In addition, by reducing the amount of water in the tank 22-1 and increasing the buoyancy of the bow of the underwater vehicle 6, a trim tilt is generated in which the bow of the underwater vehicle 6 points upward. In contrast, by reducing the amount of water in the tank 22-5 and increasing the buoyancy of the stern of the underwater vehicle 6, a trim tilt is generated in which the bow of the underwater vehicle 6 points downward. This makes it possible to adjust the pitch angle, which is one of the attitude angles of the underwater vehicle 6 in the water, to an arbitrary angle as shown by the arrow 52. In addition, for example, the tanks 22-2 and 22-3 are positioned near the center of gravity of the underwater vehicle 6, symmetrically on the left and right of the roll axis, which is the central axis extending from the bow to the stern, and the roll angle, which is one of the attitude angles of the underwater vehicle 6, can be adjusted to any angle by changing the balance of the water volume in the tanks 22-2 and 22-3.

2, the actuator 21 includes, for example, pumps 21P-1 to 21P-7 and valves 21V-1 to 21V-15. The pumps 21P-1 to 21P-7 and the valves 21V-1 to 21V-15 each incorporate a drive means such as a motor. When the pumps 21P-1 to 21P-7 receive a control signal to turn them on, the drive means operates to take in water stored in the tanks 22-1 to 22-5 connected to each of the pumps through piping and discharge it from the other piping, and when the pumps receive a control signal to turn them off, the drive means stops and the intake of water stops. When the valves 21V-1 to 21V-15 receive a control signal to turn them on, the drive means operates to open the valve, and when the valves receive a control signal to turn them off, the drive means operates to close the valve. Pumps 21P-1 to 21P-7 and valves 21V-1 to 21V-15 are turned on and off by control signals to fill, drain, and transfer water to and from tanks 22-1 to 22-5.

In FIG. 2, tank 22 includes five tanks 22-1 to 22-5 as an example, but the number of tanks included in tank 22 is not limited to five and may be any number as long as it is plural. In addition, the number and arrangement of pumps 21P-1 to 21P-7 and valves 21V-1 to 21V-15 in FIG. 2 are examples and will increase or decrease depending on the number of tanks 22-1 to 22-5. In addition, for example, if the specifications are such that filling and draining are performed only in tank 22-3, the arrangement will differ depending on the specifications, and pump 21P-3 for filling and draining tank 22-3, valves 21V-3 and 21V-8, pumps 21P-6 and 21P-7 for transferring water, and valves 21V-11 to 21V15 will be provided.

As shown by the dashed arrows in Figure 1, the underwater vehicle 6 is subjected to the force and moment of buoyancy generated by the tank 22, the force and moment caused by the motion control device 4, and the force and moment caused by disturbances such as changes in underwater density when the underwater vehicle 6 is located in the sea. The action of these forces and moments changes the depth, pitch angle, roll angle, etc. of the underwater vehicle 6. The detection unit 5 is a sensor such as a gyro, and detects control amounts corresponding to each of the control indices related to the state of the underwater vehicle 6, such as attitude angles such as pitch angle and roll angle, and depth. The detection unit 5 outputs the detected control amounts as feedback values to the motion control system control device 3 and the water volume control system control device 1.

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 is specified as an arbitrary value, and a control amount detected by the detection unit 5 and that corresponds to the predetermined control index. The motion control device 4 is, for example, a control device including 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, movement direction, movement speed, etc. of the underwater vehicle 6.

The water volume control system control device 1 is a device that adjusts the water volume of the tank 22 provided in the tank system 2, which is the control target of a redundant multi-input system. The water volume control system control device 1 includes a calculation unit 11, a feedback control unit 12, 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), and the adjustment amount calculation unit 13 is a functional unit provided to solve the above-mentioned (Problem 3). Below, the design guidelines for the feedback control unit 12 and the adjustment amount calculation unit 13 are explained.

(Feedback control section design guidelines)
The control system 100 of FIG. 1 can be shown in FIG. 3 as a block diagram of the control system. In FIG. 3, the water volume control system 61 is a transmission element corresponding to the water volume 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 as a structure that is a controlled object by force and moment. The summing point 60 takes in the water volume control system target value and the control amount output by the controlled object 65, calculates an error by subtracting the control amount from the water volume control system target value, and outputs the calculated error to the water volume 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 volume control system 61, and the force and moment due to disturbance, adds them up for each force and moment, and outputs the sum of the force and the sum of the moment to the controlled object 65. The summing point 66 takes in the motion control system target value and the control amount output by the controlled object 65 , subtracts the control amount from the motion control system target value to calculate an error, and outputs the calculated error to the motion control system 67 .

In order to compensate for the response delay caused by the capacity constraint of the actuator 21, which is problem 1 described above, the water volume control system 61 includes, for example, a transfer element 63 that simulates 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 the following equation (1). The parameter T _a in equation (1) is determined so as to simulate the response delay caused by the capacity constraint of the actuator 21.

The water volume control system 61 also includes a transfer element 62 that performs calculations of the PID control method shown in the following equation (2), for example, to reduce 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.

The control system is designed based on the block diagram of Fig. 3, and the control gains of the PID control method, i.e., the parameters _Kpt , _Tit , and _Tdt in formula (2) are determined so that the control system converges by feedback control. In this design, it is most ideal to design the control band of the motion control system 67 and the control band of the water volume control system 61 in a state where they do not interfere with each other at all. However, in actual design, the parameters Kpt, Tit, and Tdt are determined so that the control band of the water volume control system 61 is sufficiently small relative to the control band of the motion control system 67, while confirming that the control band of the motion control system 67 and the control band of the water volume control system 61 do not interfere with each other in the controlled object ₆₅ , causing _hunting or the _like . The force and moment obtained by controlling the tank 22 in the water volume control system 61 are larger than the force and moment obtained by controlling the rudder, thruster, etc. in the motion control system 67, but in terms of the response time until the effect of the force and moment appears, the response time of the motion control system 67 is shorter than the response time 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 effect on the control of the tank 22 is small, and 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.

By carrying out the above design and finding appropriate parameters _Kpt , _Tit , and _Tdt , it is possible to prevent instability due to the capacity constraints of actuator 21 and realize a stable control system that does not exceed the capacity constraints of actuator 21. It is also possible to realize a control system that suppresses interference between the control band of motion control system 67 and the control band of water volume control system 61. This makes it possible to perform coordinated control between motion control system 67 and water volume control system 61. Therefore, by performing feedback control that converges the control amount output by 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).

The 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 summing point 60, and takes in a water volume control system target value that is a water volume control system target value corresponding to a predetermined control index and is specified to an arbitrary value, and a control amount that is a control amount detected by the detection unit 5 and corresponds to the predetermined control index. The calculation unit 11 calculates an error by subtracting the control amount from the water volume control system target value, and outputs the calculated error to the feedback control unit 12. The feedback control unit 12 is a PID controller that performs PID control calculations corresponding to the transfer element 62 whose parameters _Kpt , _Tit , and _Tdt are determined by the above-mentioned design. The feedback control unit 12 calculates a command value from the error output by the calculation unit 11 through the PID control calculation. The feedback control unit 12 outputs the calculated command value to the adjustment amount calculation unit 13.

At least one predetermined control index is set, and when multiple control indexes are set, the calculation unit 11 takes in the water volume control system target value and the control amount corresponding to each of the multiple control indexes. In this case, the feedback control unit 12 calculates multiple command values corresponding to each of the multiple control indexes based on each of the multiple errors corresponding to each of the multiple control indexes output by the calculation unit 11.

(Design guidelines for 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 for solving (Problem 3), the Lagrange's method of undetermined multipliers, which is capable of finding an analytical optimal solution and is easy to implement in an embedded device and to change parameters on-site, is adopted. Hereinafter, an example of a procedure for applying an arithmetic equation for calculating an optimal solution obtained by analysis using the Lagrange's method of undetermined multipliers to the adjustment amount calculation unit 13 will be described with reference to FIG. 4.

In order to use the Lagrange undetermined multiplier method, an objective function and constraint conditions in the Lagrange equation are set in advance (step S1). Here, the objective function is a function indicating the adjustment conditions for the water amounts of the tanks 22-1 to 22-5. The adjustment conditions for the water amounts of the tanks 22-1 to 22-5 are, for example, a condition to minimize the energy consumption required for adjusting the water amounts, a condition to level the water amounts distributed to each of the tanks 22-1 to 22-5, and a condition to minimize the adjustment time required for adjusting the water amounts. Here, as an example, the condition to minimize the energy consumption required for adjusting the water amounts is set as the objective function f ₁ (x ₁ , x ₂ ), and the condition to level the water amounts distributed to each of the tanks 22-1 to 22-5 is set as the objective function f ₂ (x ₁ , x ₂ ).

The constraint condition is a function indicating a state condition indicating the state of the underwater vehicle 6. The state condition indicating the state of the underwater vehicle 6 is, for example, a condition in which the unbalance amount related to the state of the underwater vehicle 6, such as the depth and the attitude angle, is set to a target value. For example, when the objective is to bring the state of the underwater vehicle 6, such as the depth and the attitude, into a balanced state, the target value is set to "0". Here, as an example, as the state condition, a constraint condition g ₁ (x ₁ , x ₂ ) in which the unbalance amount in the vertical direction of the underwater vehicle 6 is set to a target value, and a constraint condition g ₂ (x ₁ , x ₂ ) in which the unbalance amount in the pitch axis direction of the underwater vehicle 6 is set to a target value are defined. Here, in order to show a general example, two variables x ₁ and x ₂ are shown in the objective function and the constraint condition, but in the case of the control system 100 of FIG. 1, the adjustment amount of the water amount for each of the five tanks 22-1 to 22-5 is a variable, so five variables are defined.

In step S1, Lagrange multipliers λ1 and λ2 are added to the objective functions _f1 ( _x1 , _x2 ) and _f2 ( _x1 , _x2 ) and constraint conditions _g1 ( _x1 , _x2 ) and _g2 ( _x1 , _x2 ) set in step _S1 to formulate a Lagrange equation (step S2). Functions _h1 (.,.) _{and h2} (.,.) that calculate the optimal solution of _x1 and _x2 for input values _u1 and _u2 are obtained by analysis using the Lagrange undetermined multiplier method (step S3). Here, the input values _u1 and _u2 correspond to the command values output by the feedback control unit 12 of the water volume control system control device 1 in FIG. 1. In addition, in FIG. 4, two input values u ₁ and u ₂ and two output values x ₁ and x ₂ are shown as an example, but the number of input values does not have to be the same as the number of output values.

A computer that executes a calculation formula of a function _h1 (.,.) and _h2 (.,.) that calculates the optimal solution for _x1 and _x2 is implemented as the adjustment amount calculation unit 13 (step S4). This allows the adjustment amount calculation unit 13 to calculate the optimal adjustment amount of 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 and the calculation formula that calculates the optimal solution obtained by the above procedure. Therefore, the adjustment amount calculation unit 13 can solve (Problem 3).

By solving (Problem 3), for example, by setting three conditions as objective functions, namely, a condition of minimizing the energy consumption required for adjusting the water volume, a condition of leveling the water volume distributed to each of the tanks 22-1 to 22-5, and a condition of minimizing the adjustment time required for adjusting the water volume, the control system 100 can obtain the following three effects. That is, when the condition of minimizing the energy consumption required for adjusting the water volume is set, for example, the operating rate of the pumps 21P-1 to 21P-7 can be reduced, and the underwater vehicle 6 can be quieted accordingly. Also, when the condition of leveling the water volume 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 leveled. When any of the tanks 22-1 to 22-5 becomes full, the response time due to the transfer of water or the filling and draining of the tanks 22-1 to 22-5 may be long depending on the specifications of the tank system 2. In such a case, by leveling 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 leveled out the next time the amount of water in the tanks 22-1 to 22-5 is adjusted. In addition, if a condition is set that the adjustment time required to adjust the amount of water is minimized, for example, the time required to transfer water to and adjust the filling and draining of water in and out of the tanks 22-1 to 22-5 can be shortened, making it possible to converge the state of the depth, attitude, and other conditions of the underwater vehicle 6 to a stable state in a short period of time.

Returning to FIG. 1, the actuator control unit 14 generates control signals to turn on or off the drive means of the actuators 21, 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 previously stored in an internal storage area. As described above, the specifications for water transfer and pouring/draining of the tank system 2 vary depending on the product used. For example, in addition to specifications in which the above-mentioned pouring/draining is performed only in tank 22-3, there are also specifications in which water cannot be transferred from the other tanks 22-1, 22-2, 22-4, and 22-5 to tank 22-3 when pouring/draining is being performed in tank 22-3. The format of the control signal for turning on or off also varies depending on the product. For this reason, the actuator control unit 14 stores conversion rule data reflecting product-specific rules and product-specific logic in an internal storage area in advance, and generates an ON/OFF control signal for the actuator 21 from the adjustment amount calculated by the adjustment amount calculation unit 13 using this conversion rule data. As the actuator control unit 14, for example, a rule-based water transfer/filling/draining controller equipped with the conversion rule data is applied.

As shown in the first embodiment, the design guidelines for the feedback control unit 12 have been presented to solve the following problems: (1) to compensate for the response delay caused by the capacity constraints of the actuator 21; and (2) 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 and the control band of the motion control system in order to cooperate with the existing control system, the motion control system. In addition, the design guidelines for the adjustment amount calculation unit 13 have been presented to solve the following problem: (3) to calculate 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 the target value specified when controlling the float and trim. By providing the feedback control unit 12 and the adjustment amount calculation unit 13 designed based on such design guidelines, it is possible to reduce the burden of many input operations that have been performed by a person on the tank system 2 up to now. In addition, the adjustment amount calculation unit 13 executes an arithmetic expression for calculating the optimal water volume adjustment amount for the tanks 22-1 to 22-5 specified by arbitrarily determined adjustment conditions and state conditions. This makes it possible to construct a control system 100 that is suited to the purpose of control of the underwater vehicle 6 and the state of the underwater vehicle 6, such as its depth and attitude. Therefore, the control system 100 makes it possible to optimize the water levels in 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 actuators 21 and coordinating with an existing control system.

Second Embodiment
In the second embodiment, a more specific configuration designed in accordance with the design guidelines for the feedback control unit 12 and the adjustment amount calculation unit 13 shown in the first embodiment will be described. Fig. 5 is a block diagram showing an example of the configuration of a control system 100a according to the second embodiment, and the relationship between the forces and moments acting on the underwater vehicle 6a by the control of the control system 100a. Note that in the control system 100a, the same components as those in the control system 100 are given the same reference numerals, and different components will be described below.

The control system 100a includes a water volume control system control device 1a, a tank system 2, a motion control system control device 3a, a rudder control device 4a, and a detection unit 5a. The underwater vehicle 6a is an unmanned underwater vehicle that autonomously navigates underwater, for example, a UUV, similar to the underwater vehicle 6 of the first embodiment. Note that, like FIG. 1, FIG. 5 is a block diagram including 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 provided in the underwater vehicle 6a. Also, in FIG. 5, like FIG. 1, solid lines indicate electrical connections, and dashed lines indicate forces and moments acting on the underwater vehicle 6a.

The adders 7 and 8 are not functional parts that actually exist, but are functional parts for convenience of explanation to simply show the relationship between the forces and moments acting on the underwater vehicle 6a. The adder 7 adds the buoyancy generated by the tank 22 and the force generated by a rudder for adjusting the depth (hereinafter referred to as a depth adjustment rudder) included in the rudder control device 4a, and outputs the sum of the added forces. The adder 7 also adds the moment of the buoyancy generated by the tank 22 and the moment generated by a rudder for adjusting the pitch angle (hereinafter referred to as a pitch adjustment rudder) included in the rudder control device 4a, and outputs the sum of the added moments. The adder 8 adds the sum of the forces output by the adder 7 and a force due to disturbance (F _d ). The force added by the adder 8 acts on the underwater vehicle 6a. The adder 8 also adds the sum of the moments output by the adder 7 and a moment due to disturbance (M _d ). The moment added by the adder 8 acts on the underwater vehicle 6a. As a result, the force output by the adder 7 acts in the up and down directions of the underwater vehicle 6a, and the moment output by the adder 7 acts in the pitch axis direction of the underwater vehicle 6a.

The detector 5a detects two control quantities, namely, depth and pitch angle, which are control indices for the underwater vehicle 6a. The depth is measured in units of, for example, [m], and the pitch angle is measured in units of, for example, [rad]. The detector 5a outputs the detected depth and pitch angle to the motion control system control device 3a.

The motion control system control device 3a includes calculation units 31-1 and 31-2, a depth FB (Feedback) 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 is specified to an arbitrary value, and the depth control amount detected by the detection unit 5a. The calculation unit 31-1 subtracts the depth control amount from the depth target value to calculate an error, and outputs the calculated error to the depth FB control unit 32-1. The depth target value is in units of [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 feedback 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.

The calculation unit 31-2 takes in the pitch angle target value, which is a motion control system target value corresponding to a predetermined pitch angle control index and is 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 pitch angle target value is in units of [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 volume control system control device 1a.

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

In the control system 100 of the first embodiment, the control amount detected by the detection unit 5 is fed back to the water volume control system control device 1 as a feedback value. In contrast, in the control system 100a of the second embodiment, the depth adjustment steering angle command value (δb) calculated by the depth FB control unit 32-1 and the pitch angle adjustment steering angle command value (δr) calculated by the pitch angle FB control unit 32-2 are fed back to the water volume control system control device 1a as feedback values as described above. As in the first embodiment, the water volume control system control device 1a has the advantage of referring to the control amount detected by the detection unit 5a as a feedback value, since it does not go through the motion control system control device 3a, the response time is shorter. In contrast, the depth adjustment steering 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 steering 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 on 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 volume 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 is longer, there is an advantage in that the rudder angle command value contains information on the rudder control, making it easier for the water volume control system control device 1a and the motion control system control device 3a to cooperate with each other.

The water volume control system control device 1a includes calculation units 11-1 and 11-2, a feedback control unit 12a, an adjustment amount calculation unit 13a, and an actuator control unit 14. The calculation unit 11-1 takes in a water volume control system target value corresponding to a predetermined depth control index, which is a float target value designated to an arbitrary value, and a depth adjustment rudder angle command value (δb) output by the depth FB control unit 32-1. The calculation unit 11-1 calculates an error by subtracting the depth adjustment rudder angle command value (δb) from the float target value, and outputs the calculated error to the float FB control unit 12-1 of the feedback control unit 12a. The calculation unit 11-2 takes in a trim target value corresponding to a predetermined pitch angle control index, which is a water volume control system target value designated 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 calculation unit 11-2 subtracts the pitch angle adjustment steering angle command value (δr) from the trim target value to calculate the error, and outputs the calculated error to the trim FB control unit 12-2 of the feedback control unit 12a.

Here, the value specified as the float target value is the float indicating a force, and the unit of the float target value is, for example, [N]. The value specified as the trim target value is the trim control moment indicating a 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 adjustment rudder angle command value (δr) are angles, and the unit is, for example, [rad]. Therefore, the target value and the feedback value given to each of the calculation units 11-1 and 11-2 have different units. Therefore, the calculation unit 11-1 converts the depth adjustment rudder angle command value, which is a feedback value, into units of "N", and the calculation unit 11-2 converts the pitch adjustment rudder angle command value, which is a feedback value, into units of "N·m", and then performs a subtraction calculation from the target value given to each.

For example, the force acting in the vertical direction of the underwater vehicle 6a by the depth adjustment rudder angle command value (δb) can be estimated from the time series change in the depth adjustment rudder angle command value (δr). Also, the moment acting in the pitch axis direction of the underwater vehicle 6a by the pitch adjustment rudder angle command value (δr) can be estimated from the time series change in the pitch adjustment rudder angle command value (δr). The calculation unit 11-1 can convert to units of force by taking in multiple consecutive depth adjustment rudder angle command values (δb) in a time series and calculating an estimated force from the multiple depth adjustment rudder angle command values (δb) that have been taken in. Also, the calculation unit 11-2 can convert to units of moment by taking in multiple consecutive pitch adjustment rudder angle command values (δr) in a time series and calculating an estimated moment from the multiple pitch adjustment rudder angle command values (δr) that have been taken in.

The feedback control section 12a includes a floatation amount FB control section 12-1 and a trim FB control section 12-2. Each of the floatation amount FB control section 12-1 and the trim FB control section 12-2 is a PID controller that performs a calculation corresponding to the transfer element 62 designed according to the above-mentioned "design guideline for feedback control section". However, unlike the control system 100, the control system 100a is configured to feed back two steering angle command values output by the motion control system control device 3a to the water volume control system control device 1a. Therefore, when designing the control system, the design is performed taking into account the difference in configuration between the control system 100 of the first embodiment and the control system 100a of the second embodiment, and the parameters _Kpt , _Tit , and _Tdt of the PID controller to be applied to each of the floatation amount FB control section 12-1 and the trim FB control section 12-2 are determined. Incidentally, since the PID control methods of the floating amount FB control section 12-1 and the trim FB control section 12-2 are designed individually, the respective parameters _Kpt , _Tit , and _Tdt will be different, but they may match depending on the design.

The float amount FB control unit 12-1 performs a PID control calculation on the error output by the calculation unit 11-1, and calculates an up/down command value (F _c ) for the float amount target value. The float amount FB control unit 12-1 outputs the calculated up/down command value (F _c ) to the adjustment amount calculation unit 13a. The trim FB control unit 12-2 performs a PID control calculation on the error output by the calculation unit 11-2, and calculates a trim command value (M _c ) for the trim target value. The trim FB control unit 12-2 outputs the calculated trim command value (M _c ) to the adjustment amount calculation unit 13a.

The adjustment amount calculation unit 13a executes an arithmetic expression for calculating an optimal solution previously obtained by an analysis using Lagrange's undetermined multiplier method in accordance with the above-mentioned "design guideline for the adjustment amount calculation unit", i.e., an arithmetic expression for calculating optimal adjustment amounts V ₁ to V ₅ for each of the tanks 22-1 to 22-5. The adjustment amount calculation unit 13a calculates water amount adjustment amounts (ΔV 1 to ΔV ₅ ) for each of the tanks 22-1 to 22-5 based on the up/down command value (F _c ) output by the floatation amount FB control unit 12-1 and the trim command value (M _c ) output by the trim FB control unit 12-2. The adjustment amount calculation unit 13a outputs the calculated water amount adjustment amounts (ΔV ₁ to ΔV _{5 )} for each of the tanks 22-1 to 22-5 to the actuator control unit 14.

(An example of an arithmetic formula for calculating an optimal solution applied to the adjustment amount calculation unit)
Here, as an example, a method will be described in which a motion model of the underwater vehicle 6a is defined as a linear model limited to a depth and a pitch angle, and then an arithmetic expression for calculating an optimal solution to be applied to the adjustment amount calculation unit 13a is obtained by the Lagrange method of undetermined multipliers. The linear model for depth can be expressed as the equation of motion of the following equation (3).

The names and units of the physical parameters shown in formula (3) are as shown in the table in FIG. 6. The "w" with "·" on the left side of formula (3) is the derivative of the depth velocity, i.e., the depth acceleration, and by multiplying the depth acceleration by the depth axis mass "m _z ", it indicates the force acting in the vertical direction of the underwater vehicle 6a, that is, in the Z-axis direction when the pitch axis and roll axis of the underwater vehicle 6a are on a horizontal plane, the roll axis is the X-axis and the pitch axis is the Y-axis. The first term "-D _z w" on the right side of formula (3) is a velocity damping term obtained by multiplying the viscous resistance coefficient by the depth velocity, and indicates the viscous force acting when the underwater vehicle 6a sinks. The second term "K _δb δb" on the right side of formula (3) indicates the force acting in the vertical direction of the underwater vehicle 6a by the depth adjustment rudder. "F _d " in the third term on the right side of equation (3) is a disturbance force acting in the vertical direction of the underwater vehicle 6a due to disturbance, and indicates an imbalance in the weight of the underwater vehicle 6a. When a rudder angle is present in the depth adjustment rudder during steady state, the force due to the rudder angle is regarded as a static disturbance force, and the force due to the rudder angle is added to "F _d ". "F _t (ΔV ₁ , ΔV ₂ , ΔV ₃ , ΔV ₄ , ΔV ₅ ) " in the fourth term on the right side of equation (3) is a vertical control force, and indicates the buoyancy generated in the vertical direction of the underwater vehicle 6a by the tanks 22-1 to 22-5.

The linear model for the pitch angle can be expressed as the following equation of motion (4):

The names and units of the physical parameters shown in formula (4) are as shown in the table in FIG. 6. The "q" with "." on the left side of formula (4) 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 _p to indicate the moment of rotational force acting on the underwater vehicle 6a about the pitch axis of the underwater vehicle 6a. The first term "-D _p q" on the right side of formula (4) is a velocity damping term obtained by multiplying the viscous resistance coefficient by the pitch angular velocity, and indicates the moment of viscous force acting in the pitch axis direction of the underwater vehicle 6a when the underwater vehicle 6a rotates about the pitch axis. In the second term "-K _p θ" on the right side of formula (4), "K _p " is the righting 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 the tilt. Therefore, "-K _p θ" indicates the moment of the restoring force acting in the pitch axis direction of the underwater vehicle 6a when the underwater vehicle 6a tilts at an angle of "θ" in the pitch axis direction.

The third term "K _δr δr" on the right side of equation (4) indicates the moment acting in the pitch axis direction of the underwater vehicle 6a by the pitch angle adjustment rudder. The fourth term "M _d " on the right side of equation (4) indicates the moment of disturbance force acting in the pitch axis direction of the underwater vehicle 6a due to disturbance. When a rudder angle is present in the pitch angle adjustment rudder in a steady state, the moment due to the rudder angle is regarded as a static disturbance moment, and the moment due to the rudder angle is added to "M _d ". The fifth term "M _t (ΔV ₁ , ΔV ₂ , ΔV ₃ , ΔV ₄ , ΔV ₅ )" on the right side of equation (4) is the trim control moment, and indicates the moment of buoyancy acting in the pitch axis direction of the underwater vehicle 6a by the tanks 22-1 to 22-5. As described above, ΔV ₁ , ΔV ₂ , ΔV ₃ , ΔV ₄ , and ΔV ₅ in equations (3) and (4) are adjustment amounts that indicate increases or decreases in the amounts of water in the tanks 22-1, 22-2, 22-3, 22-4, and 22-5, respectively, calculated by the adjustment amount calculation unit 13a.

The state conditions indicating the state of the underwater vehicle 6a are the constraint conditions in the Lagrange's method of undetermined multipliers. Here, as the state conditions indicating the state of the underwater vehicle 6a, the state conditions are adopted in which the unbalance amount in the vertical direction and the unbalance amount in the pitch axis direction of the underwater vehicle 6a are both "0". The state in which the unbalance amount in the vertical direction is "0" means that the underwater weight of the underwater vehicle 6a is "0 kg" and the vehicle is in a neutral buoyancy state. In addition, the state in which the unbalance amount in the pitch axis direction is "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 speed of the underwater vehicle 6a is constant and the vehicle is in an equilibrium state, the constraint conditions can be expressed as the following equations (5) and (6).

It is assumed that the first to third terms on the right side of the formula (5) are compensated by the up/down command value F _c [N] output by the floatation amount FB control unit 12-1. It is also assumed that the first to fourth terms on the right side of the formula (6) are compensated by the trim command value M _c [N·m] output by the trim FB control unit 12-2. As described above, when the depth adjustment rudder and the pitch angle adjustment rudder have rudder angles in the steady state, the force and moment due to the rudder angle existing in the steady state are added to "F _d " and "M _d ", respectively, but it is also assumed that the force and moment due to the rudder angle existing in the steady state are also offset by "F _c " and "M _c ". In this case, the constraint conditions of the formulas (5) and (6) are expressed as the following formulas (7) and (8), respectively.

Here, the buoyancy (F _t ) and the buoyancy moment (M _t ) due to the tanks 22-1 to 22-5 can be calculated by the following equations (9) and (10), respectively.

In equations (9) and (10), ρ is the density of seawater [kg/m ³ ], g is the acceleration of gravity [m/s ² ], and in equation (10), l ₁ to l ₅ are the distances from the center of gravity of the underwater vehicle 6a to the centers of gravity of the tanks 22-1 to 22-5, respectively.

By applying equations (9) and (10) to equations (7) and (8), equations (7) and (8) can be transformed into the following equations (11) and (12).

Here, we define the following equation (13) as the objective function for the Lagrange multiplier method.

Equation (13) is an evaluation function that evaluates the amount of water moving between tanks 22-1 to 22-5, and indicates the adjustment conditions for the water volume in tanks 22-1 to 22-5. Minimizing the evaluation function of equation (13) means minimizing the amount of adjustment of the water volume in tanks 22-1 to 22-5. Minimizing the amount of adjustment of the water volume in tanks 22-1 to 22-5 means minimizing the operating rate of pumps 21P-1 to 21P-7 and also minimizing energy consumption.

The Lagrange equation shown in the following equation (14) is formulated using the constraint conditions of equations (11) and (12), the objective function of equation (13), and Lagrange multipliers λ ₁ and λ ₂ .

The optimal solution of equation (14) can be obtained by partially differentiating equation (14) with respect to variables ΔV ₁ to ΔV ₅ and Lagrange multipliers λ ₁ and λ ₂ , as shown in the following equation (15), under the condition that each of the equations becomes "0".

From equation (15), a simultaneous equation consisting of seven equations can be derived. By eliminating λ ₁ and λ ₂ from the simultaneous equation consisting of seven equations, it is possible to obtain an arithmetic equation for calculating an optimal solution from the up/down command value (F _c ) output by the floatation amount FB control unit 12-1 and the trim command value (M _c ) output by the trim FB control unit 12-2, that is, an arithmetic equation for calculating the optimal adjustment amounts ΔV ₁ to ΔV ₅ for each of the tanks 22-1 to 22-5. A computer that executes the arithmetic equation for calculating the optimal solution obtained as described above is referred to as the adjustment amount calculation unit 13a.

(Processing by the control system of the second embodiment)
The process performed by the control system 100a of the second embodiment will be described below.

(Processing by the motion control system)
Fig. 7 is a flow chart showing the flow of processing by the motion control system control device 3a and the rudder control device 4a. Before the processing of Fig. 7 is started, a depth target value and a pitch angle target value are specified for the motion control system control device 3a. Also, it is assumed that the detection unit 5a repeatedly detects the control amounts of the depth and pitch angle at regular intervals. Also, for example, the motion control system control device 3a is provided with an ON/OFF switch, and the processing shown in Fig. 7 is started by switching the ON state.

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 subtracts the depth control amount from the depth target value to calculate an error, 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 error taken in. 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 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 pitch angle feedback 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 taken-in error. The pitch angle feedback control unit 32-2 outputs the calculated pitch angle adjustment rudder angle command value (δr) to the rudder control device 4a (step Sa2-2).

The rudder control device 4a changes the orientation of the depth adjustment rudder in response to the depth adjustment rudder angle command value (δb) output by the depth feedback control unit 32-1. As a result, a combined force of the depth adjustment rudder force and the disturbance force (F _d ) acts on the underwater vehicle 6a, changing the depth of the underwater vehicle 6a (step Sa3-1). The rudder control device 4a changes the orientation of the pitch adjustment rudder in response to the pitch adjustment rudder angle command value (δr) output by the pitch angle feedback control unit 32-2. As a result, a combined moment of the pitch adjustment rudder moment and the disturbance moment (M _d ) acts on the underwater vehicle 6a, changing the pitch angle of the underwater vehicle 6a (step Sa3-2).

If the ON/OFF switch of the motion control system control device 3a is in the ON state, it is assumed that control by the motion control system is 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 feedback control unit 32-1, and the pitch angle feedback control unit 32-2 stop operating (step Sa4, No), and the processing ends.

In the process of FIG. 7, the process of steps Sa2-1 and Sa3-1 and the process of steps Sa2-2 and Sa3-2 are performed in parallel.

(Processing by water volume control system)
Fig. 8 is a flow chart showing the flow of processing by the water volume control system control device 1a and the tank system 2. Before the processing of Fig. 8 is started, a float target value and a trim target value are specified for the water volume control system control device 1a. It is also assumed that the detection unit 5a repeatedly detects the control amounts of depth and pitch angle at regular intervals. It is also assumed that the motion control system control device 3a and the rudder control device 4a continue to perform the processing shown in Fig. 7 while the motion control system control device 3a is ON. It is also assumed that, for example, the water volume control system control device 1a is provided with an ON/OFF switch, and the processing shown in Fig. 8 is started by switching it to the ON state.

The calculation unit 11-1 takes in the specified float target value and the depth adjustment rudder angle command value (δb) output by the depth FB control unit 32-1. The calculation unit 11-1 converts the depth adjustment rudder angle command value (δb) into the unit of the float target value, subtracts the converted depth adjustment rudder angle command value (δb) from the float target value to calculate the error, and outputs the calculated error to the float FB control unit 12-1. The calculation unit 11-2 takes in 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 calculation unit 11-2 converts the pitch angle adjustment rudder angle command value (δr) into the unit of the trim target value, 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).

The float amount FB control unit 12-1 calculates a vertical command value (F _c ) from the error output by the calculation unit 11-1 using a PID control calculation. The float amount FB control unit 12-1 outputs the calculated vertical command value (F _c ) to the adjustment amount calculation unit 13a (step Sb2-1). The trim FB control unit 12-2 calculates a trim command value (M _c ) from the error output by the calculation unit 11-2 using a PID control calculation. The trim FB control unit 12-2 outputs the calculated trim command value (M _c ) to the adjustment amount calculation unit 13a (step Sb2-2).

The adjustment amount calculation unit 13a takes in the up/down command value (F _c ) output by the floatation amount FB control unit 12-1 and the trim command value (M _c ) output by the trim FB control unit 12-2. The adjustment amount calculation unit 13a receives the up/down command value (F _c ) and the trim command value (M _c ) as inputs, and calculates the adjustment amounts ΔV ₁ to ΔV ₅ by performing calculations using equations for calculating optimal solutions. The adjustment amount calculation unit 13a outputs the calculated adjustment amounts ΔV ₁ to ΔV ₅ to the actuator control unit 14 (step Sb3).

Based on the adjustment amounts ΔV ₁ to ΔV ₅ output by the adjustment amount calculation unit 13a and conversion rule data previously stored in an internal storage area, the actuator control unit 14 generates control signals for turning on or off the drive means of the pumps 21P-1 to 21P-7 and valves 21V-1 to 21V-15, which are the actuators 21. The actuator control unit 14 outputs each of the generated control signals to the drive means of the corresponding pumps 21P-1 to 21P-7 and valves 21V-1 to 21V-15 (step Sb4).

When the driving means of the pumps 21P-1 to 21P-7 and the valves 21V-1 to 21V-15 receive a control signal from the actuator control unit 14 to turn them on or off, they start operating according to the control signal, thereby transferring water and filling or draining it in the tanks 22-1 to 22-5 (step Sb5).

If the ON/OFF switch of the water volume control system control device 1a is in the ON state, it is assumed that control by the water volume control system is continuing (step Sb6, Yes), and the processing from step Sb1 onwards is carried out. On the other hand, if the ON/OFF switch of the water volume control system control device 1a is in the OFF state, the calculation units 11-1, 11-2, floatation amount FB control unit 12-1, trim FB control unit 12-2, adjustment amount calculation unit 13a, and actuator control unit 14 stop operating (step Sb6, No), and the processing ends.

Note that in the process of FIG. 8, the process of step Sb2-1 and the process of step Sb2-2 are performed in parallel.

(Simulation results)
9 and 10 are graphs showing the results of a simulation performed using the control system 100a. In the graphs of FIG. 9 and FIG. 10, the horizontal axis indicates elapsed time in seconds, and the time at the left end of the horizontal axis is "0 seconds". In FIG. 9 and FIG. 10, the times indicated by the vertical dashed lines are the same, and this time is the time when the water volume control system control device 1a is turned on, that is, the time when the water volume control system control device 1a starts the process shown in FIG. 8. At time "0 seconds", the detection unit 5a starts the process of detecting the control amount of the depth and the pitch angle at regular intervals. The motion control system control device 3a is turned on at time "0 seconds" and starts the process shown in FIG. 7. In addition, the depth target value indicated by the dashed line of reference numeral 71 in FIG. 9(e) and the pitch angle target value indicated by the dashed line of reference numeral 72 in FIG. 9(f) are specified for the motion control system control device 3a.

In Figures 9(c), (d), and (f), values obtained in units of [rad] are converted into units of [deg]. In addition, the units of [tonf (ton-force)] and "tonf・m" in the graphs of Figures 9(a), (b), (g), and (h) are values obtained in units of [N] and [N・m] converted into units of [tonf] and [tonf・m].

The graphs in Figures 10(a), (b), (c), (d), and (e) show the amount of water in tanks 22-1, 22-2, 22-3, 22-4, and 22-5, respectively, as a percentage, and assume that at time "0 seconds" each of tanks 22-1 to 22-5 contains the same amount of water.

As shown in the graphs of Figures 9(a) and (b), a certain disturbance force (F _d ) and a certain disturbance moment (M _d ) are applied to the underwater vehicle 6a a little after time 0 [seconds], which causes the weight balance of the underwater vehicle 6a to be lost. The depth adjustment rudder angle and the angle of the pitch angle adjustment rudder change as shown in the graphs of Figures 9(c) and (d) by the control by 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. The graphs of Figures 9(e) and (f) are graphs showing the change in the depth and pitch angle of the underwater vehicle 6a detected by the detection unit 5a, respectively. As shown in the graph of Figure 9(e), the application of the disturbance force (F _d ) causes the underwater vehicle 6a to sink and increase in depth, and then a constant depth is maintained by the control by the depth FB control unit 32-1. However, the control by the depth feedback control unit 32-1 does not converge to the depth target value indicated by the dashed line 71 in Fig. 9(e). In contrast, as shown in the graph in Fig. 9(f), the application of the disturbance moment (M _d ) causes the underwater vehicle 6a to tilt about the pitch axis, increasing the pitch angle, but then, the control by the pitch angle feedback control unit 32-2 converges to the pitch angle target value indicated by the dashed line 72.

At the time indicated by the vertical dashed line, the water volume control system control device 1a starts the process shown in FIG. 8. In the water volume control system control device 1a, the float target value indicated by the dashed line 73 in the graph of FIG. 9(g) is specified, and the trim target value indicated by the dashed line 74 in the graph of FIG. 9(h) is specified. When the control by the water volume control system control device 1a is started, the water volume of each of the tanks 22-1 to 22-5 gradually decreases as shown in the graph of FIG. 10 according to the adjustment amounts ΔV ₁ to ΔV ₅ for each of the tanks 22-1 to 22-5 calculated by the adjustment amount calculation unit 13a, 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 71 without any disturbance after the time indicated by the vertical dashed line, as shown in the graph of FIG. 9(e). As shown in the graph of Fig. 9(f), the pitch angle of the underwater vehicle 6a detected by the detector 5a is somewhat disturbed after the time indicated by the vertical dashed line, but ultimately converges to the pitch angle target value indicated by the dashed line indicated by reference numeral 72. As shown in the graphs of Fig. 9(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 in which the rudder is not controlled. As shown in the graphs of Fig. 9(g) and (h), the vertical buoyancy of the underwater vehicle 6a converges to the buoyancy target value indicated by the dashed line indicated by 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 indicated by reference numeral 74.

The configuration of the second embodiment described above allows the control system 100a to perform stable automatic control, i.e., to compensate for response delays caused by the capacity constraints of the actuator 21, to suppress interference between the control bandwidth of the water volume control system and the control bandwidth of the motion control system, which is an existing control system, to calculate 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 the buoyancy target value and the trim target value, and to transfer water to and fill/drain the tanks 22-1 to 22-5. In other words, it becomes possible to optimize the water volume of the multiple tanks so that the control system of the underwater vehicle 6a converges to the target value while taking into account the capacity constraints of the actuator 21 and coordinating with the existing control system.

The water volume control system target value and motion control system target value in the control system 100 of the first embodiment, and the floatation target value, trim target value, depth target value, and pitch angle target value in the control system 100a of the second embodiment may be values that are written in advance in the internal memory areas of the water volume control system control devices 1, 1a and the motion control system control devices 3, 3a, or the user may operate a setting device installed on land to transmit these target values to the control systems 100, 100a by acoustic communication or communication via a wired cable. Similarly, the ON/OFF state of the water volume control system control device 1a and the motion control system control device 3a in the control system 100a may be switched ON/OFF by operating a setting device installed on land by acoustic communication or communication via a wired cable.

In the above first and second embodiments, the underwater vehicle 6, 6a is, for example, an unmanned underwater vehicle, but may be a manned underwater vehicle on which a person is aboard. In the case where the person is aboard the underwater vehicle 6, 6a, the person on board may specify the water volume control system target value, the motion control system target value, the buoyancy target value, the trim target value, the depth target value, and the pitch angle target value, and may also switch the ON/OFF state of the water volume control system control device 1a and the motion control system control device 3a. In addition, when a person is aboard, the weight balance of the underwater vehicle 6, 6a may change due to the movement of the person inside. When considering the change in the weight balance of the underwater vehicle 6, 6a due to the movement of the person, the force and moment generated by the change in the weight balance can be regarded as a disturbance force and a disturbance moment, and are added to " _Fd " and " _Md ", respectively.

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, as in the control system 100 of the first embodiment, the control system 100a may also feed back the depth control amount detected by the detection unit 5a to the calculation unit 11-1 as a feedback value, and feed back the pitch angle control amount detected by the detection unit 5a to the calculation unit 11-2 as a feedback value. In addition, generally, the underwater vehicle 6, 6a is equipped with a pitch angle adjustment rudder, but may not be equipped with a depth adjustment rudder. In such a case, the control amount of the depth detected by the detection unit 5a may be fed back to the 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 may be fed back to the calculation unit 11-2 as a feedback value.

In this case, if the unit of the given feedback value does not match the unit of the float target value, the calculation unit 11-1 converts the given feedback value into the unit of the float target value, and then subtracts the converted feedback value from the float target value. Similarly, if the unit of the given feedback value does not match the unit of the trim target value, the calculation unit 11-2 converts the given feedback value into the unit of the trim target value, and then subtracts the converted feedback value from the trim target value. For example, if the feedback value is a depth control amount, the force acting in the vertical direction of the underwater vehicle 6a can be estimated from the time series change in depth. The calculation unit 11-1 can convert to the unit of force by taking in multiple consecutive depth control amounts on the time series output by the detection unit 5a and calculating an estimated force from the taken in multiple depth control amounts. Also, if the feedback value is a pitch angle control amount, the moment acting in the pitch axis direction of the underwater vehicle 6a can be estimated from the time series change in pitch angle. The calculation unit 11-2 takes in multiple consecutive pitch angle control amounts on the time series output by the detection unit 5a, and converts them into units of moment by calculating an estimated moment from the control amounts of the multiple pitch angles taken in.

In the control system 100a of the second embodiment, the feedback control unit 12a has two functional units, a floatation FB control unit 12-1 and a trim FB control unit 12-2, but it may have only one of them.

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

In the control system 100a of the second embodiment described above, instead of the rudder control device 4a, a control device that controls a thruster that adjusts the depth and pitch angle may be provided. In this case, the depth feedback 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 to the calculation unit 11-1. The pitch angle feedback 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 to the calculation unit 11-2. The control system 100a may also be provided with a control device that controls the thruster, in addition to the rudder control device 4a.

As the transfer element 62 shown in FIG. 3 of the first embodiment described above, a feedback control method such as I-PD control or PI-PD control, or a feedback control method combining stabilization techniques using nonlinear compensation and non-interference control may be applied instead of the PID control method. In this case, the feedback control unit 12 of the first embodiment, and the floatation amount 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.

The calculation formula for calculating the optimal solution executed by the adjustment amount calculation unit 13, 13a in the first and second embodiments is calculated using Lagrange's undetermined multiplier method, but an optimization method other than Lagrange's undetermined multiplier method may be applied to calculate the calculation formula for the optimal solution. In addition, if the processing capacity of the computer applied to the adjustment amount calculation unit 13, 13a is high, an optimization method may be used to directly calculate the optimal water volume adjustment amount for each of the multiple tanks 22-1 to 22-5 by performing sequential optimization calculations based on the adjustment conditions and state conditions, without calculating a calculation formula for calculating the optimal solution.

Figure 11 is a diagram showing an example of the hardware configuration of the water volume control system control device 1, 1a and the motion control system control device 3, 3a according to one embodiment. The computer 90 includes a CPU 91, a main memory device 92, an auxiliary memory device 93, an input/output interface 94, and a 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 above-mentioned functions are stored in the auxiliary memory device 93 in the form of a program. The CPU 91 reads the program from the auxiliary memory device 93, expands it in the main memory device 92, and executes the above-mentioned processing according to the program. The CPU 91 also secures a memory area in the main memory device 92 according to the program. The CPU 91 also secures a memory area in the auxiliary memory device 93 for storing data being processed according to the program.

In addition, a program for realizing all or part of the functions of the water volume control system control device 1, 1a and the motion control system control device 3, 3a may be recorded on a computer-readable recording medium, and the program recorded on the recording medium may be read into a computer system and executed to perform processing by each functional unit. The term "computer system" here includes hardware such as an OS and peripheral devices. In addition, if a WWW system is used, the term "computer system" also includes a homepage providing environment (or display environment). In addition, the term "computer-readable recording medium" refers to portable media such as CDs, DVDs, and USBs, and storage devices such as hard disks built into a computer system. In addition, if this program is distributed to a computer 90 via a communication line, the computer 90 that receives the program may expand the program into the main storage device 92 and execute the above processing. In addition, the above program may be for realizing part of the above-mentioned functions, and may further be capable of realizing the above-mentioned functions in combination with a program already recorded in the computer system.

As described above, several embodiments of the present disclosure have been described, but all of these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope of the invention and its equivalents as described in the claims, as well as in the scope and gist of the invention.

<Additional Notes>
The water volume control device 1, 1a, the control system 100, 100a, the water volume control method, and the program described in the above-described embodiments can be understood, for example, as follows.

According to a first aspect of the present disclosure, the water volume control system control device 1, 1a is a water volume control system control device 1, 1a that controls the amount of water in each of the tanks 22-1 to 22-5 of the underwater vehicle 6, 6a, which has a motion control device 4 (rudder control device 4a) that controls the motion of the underwater vehicle 6, 6a, a motion control system control device 3, 3a that calculates a command value for the motion control device 4 (rudder control device 4a) based on a motion control system target value and a control amount detected from the underwater vehicle 6, 6a, and a plurality of tanks 22-1 to 22-5 and an actuator 21 that adjusts the amount of water in each of the tanks 22-1 to 22-5, and the water volume control system control device 1, 1a controls the amount of water in each of the tanks 22-1 to 22-5 of the underwater vehicle 6, 6a, based on a water volume control system target value and a feed The feedback control unit 12, 12a receives the back value 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 21 and suppresses interference with the control band of the motion control system control device 3, 3a, and an adjustment amount calculation unit 13, 13a receives the command value calculated by the feedback control unit 12, 12a as input and calculates an adjustment amount indicating an increase or decrease in the water volume for each of the tanks 22-1 to 22-5 by an optimization method that uses adjustment conditions related to the water volume of the multiple tanks 22-1 to 22-5 and state conditions indicating the state of the underwater vehicle 6, 6a as conditions.

According to the second aspect of the present disclosure, in the water volume control system control device 1, 1a according to the first aspect, the calculation using the feedback control method is a calculation using a PID control method, and the parameters of the PID control method are determined so as to compensate for the response delay of the actuator 21 and suppress interference with the control band of the motion control system control device 3, 3a.

According to a third aspect of the present disclosure, in the water volume control system control device 1, 1a according to the first or second aspect, the optimization method is an optimization method that uses an arithmetic formula that calculates an optimal solution obtained by the Lagrange method of undetermined multipliers with the adjustment conditions as objective functions and the state conditions as constraint conditions.

According to the fourth aspect of the present disclosure, in any one of the water volume control system control devices 1, 1a according to the first to third aspects, the feedback value is either the controlled variable or the command value calculated by the motion control system control device 3, 3a.

According to a fifth aspect of the present disclosure, any one of the water volume control system control devices 1, 1a according to the first to fourth aspects includes an actuator control unit 14 that generates a control signal for the actuator 21 based on the adjustment amount calculated by the adjustment amount calculation unit 13, 13a and predetermined conversion rule data, and outputs the generated control signal to the actuator 21.

According to a sixth aspect of the present disclosure, in any one of the water volume control system control devices 1, 1a according to the first to fifth aspects, the motion control device 4 controls either the rudder of the underwater vehicle 6, 6a or the thruster of the underwater vehicle 6, 6a, or controls both.

According to a seventh aspect of the present disclosure, in any one of the water volume control system control devices 1, 1a according to the first to sixth aspects, the control amount includes a control amount related to at least one control index among the depth, pitch angle, and roll angle of the underwater vehicle 6, 6a, the water volume control system target value includes a target value corresponding to one of the control indexes included in the control amount, the feedback control unit 12, 12a receives as input each of the target values included in the water volume control system target value and the feedback value corresponding to each of the control indexes, and calculates a command value for each of the target values included in the water volume control system target value by calculation using the feedback control method, and the adjustment amount calculation unit 13, 13a receives as input the command value calculated by the feedback control unit 12, 12a for each of the target values included in the water volume control system target value, and calculates an adjustment amount indicating an increase or decrease in the water volume for each of the multiple tanks 22-1 to 22-5 by the optimization method.

According to an eighth aspect of the present disclosure, the control system 100, 100a includes a motion control device 4 (rudder control device 4a) that controls the motion of the underwater vehicle 6, 6a, a motion control system control device 3, 3a that calculates a command value for the motion control device 4 (rudder control device 4a) based on a motion control system target value and a control amount detected from the underwater vehicle 6, 6a, a plurality of tanks 22-1 to 22-5 provided on the underwater vehicle 6, 6a, an actuator 21 that adjusts the water volume of each of the tanks 22-1 to 22-5, and a water volume control system control device 1, 1a, and the water volume control system control device 1, 1a controls the water volume control system target value and The feedback control unit 12, 12a receives the feedback value as an input, 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 21 and suppresses interference with the control band of the motion control system control device 3, 3a; and an adjustment amount calculation unit 13, 13a receives the command value calculated by the feedback control unit 12, 12a as an input, and calculates an adjustment amount indicating an increase or decrease in the water volume for each of the tanks 22-1 to 22-5 by an optimization method that uses adjustment conditions related to the water volume of the multiple tanks 22-1 to 22-5 and state conditions indicating the state of the underwater vehicle 6, 6a as conditions.

According to a ninth aspect of the present disclosure, the water volume control method is a water volume control method for an underwater vehicle 6, 6a having a motion control device 4 (rudder control device 4a) that controls the motion of the underwater vehicle 6, 6a, a motion control system control device 3, 3a that calculates a command value for the motion control device 4 (rudder control device 4a) based on a motion control system target value and a control amount detected from the underwater vehicle 6, 6a, a plurality of tanks 22-1 to 22-5, and an actuator 21 that adjusts the water volume of each of the tanks 22-1 to 22-5, and the feedback value are input, a command value for the water volume control system target value is calculated by a calculation using 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 device 3, 3a, and the calculated command value is input, and an adjustment amount indicating an increase or decrease in the water volume for each of the tanks 22-1 to 22-5 is calculated using an optimization method that uses adjustment conditions related to the water volume of the multiple tanks 22-1 to 22-5 and state conditions indicating the state of the underwater vehicle 6, 6a as conditions.

According to a tenth aspect of the present disclosure, the program includes a motion control device 4 (rudder control device 4a) that controls the motion of the underwater vehicle 6, 6a, a motion control system control device 3, 3a that calculates a command value for the motion control device 4 (rudder control device 4a) based on a motion control system target value and a control amount detected from the underwater vehicle 6, 6a, a plurality of tanks 22-1 to 22-5, and an actuator 21 that adjusts the water volume of each of the tanks 22-1 to 22-5. The program includes a computer provided in the underwater vehicle 6, 6a that controls the motion of the underwater vehicle 6, 6a, the motion control system control device 3, 3a that calculates a command value for the motion control device 4 (rudder control device 4a) based on a motion control system target value and a control amount detected from the underwater vehicle 6, 6a, and the water volume control system target value and a feedback control system. The system executes a procedure of calculating a command value for the water volume control system target value by calculation using a feedback control method that uses the actuator 21 and the actuator 22-1 to compensate for the response delay of the actuator 21 and suppresses interference with the control band of the motion control system control device 3, 3a, and a procedure of calculating an adjustment amount indicating an increase or decrease in the water volume for each of the tanks 22-1 to 22-5 by an optimization method that uses the calculated command value as input and has adjustment conditions related to the water volume of the tanks 22-1 to 22-5 and state conditions indicating the state of the underwater vehicle 6, 6a as conditions.

1...Water volume control system control device, 2...Tank system, 3...Motion control system control device, 4...Motion control device, 5...Underwater vehicle, 6...Detection unit, 11...Calculation unit, 12...Feedback control unit, 13...Adjustment amount calculation unit, 14...Actuator control unit, 21...Actuator, 22...Tank

Claims (10)

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 an amount of water to be increased or decreased in each of the tanks of the underwater vehicle, the water volume control system control device having a plurality of tanks and an actuator that adjusts the amount of water in each of the tanks,
a feedback control unit that receives a water volume control system target value and a feedback value, and calculates a command value for the water volume control system target value by a calculation using a feedback control method that compensates for a response delay of the actuator and suppresses interference with the control bandwidth of the motion control system control device;
an adjustment amount calculation unit that uses the command value calculated by the feedback control unit as an 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 using adjustment conditions related to the amounts of water in the multiple tanks and state conditions indicating the state of the underwater vehicle as conditions;
A water volume control system control device comprising: The calculation by the feedback control method is
This is a calculation using a PID control method.
The parameters of the PID control method are determined so as to compensate for the response delay of the actuator and suppress interference with the control bandwidth of the motion control system control device.
The water flow control system control device according to claim 1 . The optimization method includes:
an optimization method using an arithmetic expression for calculating an optimal solution obtained by Lagrange's undetermined multiplier with the adjustment condition as an objective function and the state condition as a constraint condition,
The water flow control system control device according to claim 1 or 2. The feedback value is
The control amount is either one of the command value calculated by the motion control system control device,
The water flow control system control device according to any one of claims 1 to 3. 5. The water volume control system control device according to claim 1, further comprising: an actuator control unit that generates a control signal for the actuator based on the adjustment amount calculated by the adjustment amount calculation unit and predetermined conversion rule data, and outputs the generated control signal to the actuator. The motion control device includes:
Controlling either the rudder of the underwater vehicle or the thruster of the underwater vehicle, or controlling both.
The water flow control system control device according to any one of claims 1 to 5. the control amount includes a control amount related to at least one control index among a depth, a pitch angle, and a roll angle of the underwater vehicle;
the water volume control system target value includes a target value corresponding to any one of the control indexes included in the controlled variable,
The feedback control unit is
each of the target values included in the water volume control system target values and the feedback values corresponding to each of the control indices are input, and a command value for each of the target values included in the water volume control system target values is calculated by the feedback control method;
The adjustment amount calculation unit
the feedback control unit receives as input the command values calculated for each of the target values included in the water volume control system target values, and calculates an adjustment amount indicating an increase or decrease in the water volume for each of the multiple tanks using the optimization method;
The water flow control system control device according to any one of claims 1 to 6. 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 provided on the underwater vehicle;
A control system including an actuator for adjusting the amount of water in each of the tanks and a water amount control device,
The water volume control system control device includes:
a feedback control unit that receives a water volume control system target value and a feedback value, and calculates a command value for the water volume control system target value by a calculation using a feedback control method that compensates for a response delay of the actuator and suppresses interference with the control band of the motion control system control device;
an adjustment amount calculation unit that uses the command value calculated by the feedback control unit as an 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 using adjustment conditions related to the amounts of water in the multiple tanks and state conditions indicating the state of the underwater vehicle as conditions;
A control system comprising: 1. A water volume control method for an underwater vehicle having a motion control device that controls 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 that adjusts the water volume of each of the tanks, comprising:
a water volume control system target value and a feedback value are input, and a command value for the water volume control system target value is calculated by a feedback control method that compensates for a response delay of the actuator and suppresses interference with a control band of the motion control system control device;
calculating an adjustment amount indicating an increase or decrease in the amount of water for each of the tanks using an optimization method that uses the calculated command value as an input and has adjustment conditions related to the amount of water in the plurality of tanks and state conditions indicating the state of the underwater vehicle as conditions;
Water flow control method. a computer provided on the underwater vehicle, the computer 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 motion control system target value and a control amount detected from the underwater vehicle, a plurality of tanks, and an actuator that adjusts the amount of water in each of the tanks;
a step of calculating a command value for the water volume control system target value by a calculation using a feedback control method that inputs a water volume control system target value and a feedback value, compensates for a response delay of the actuator, and suppresses interference with a control band of the motion control system control device;
a step of calculating an adjustment amount indicating an increase or decrease in the amount of water for each of the tanks by an optimization method using the calculated command value as an input and including an adjustment condition related to the amount of water in the plurality of tanks and a state condition indicating a state of the underwater vehicle;
A program for executing.

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