Control device, underwater vehicle, and control method

Abstract

To provide a control device that achieves both fluctuation suppression and energy saving performance.SOLUTION: A control device includes: a feedback controller that calculates a control command value based on the difference between a hull position and a target position; a non-interference controller that calculates a non-interference compensation value that cancels mutual interference between control axes of the hull; a disturbance estimator that calculates a disturbance compensation value to cancel disturbance; a speed saturation compensator that calculates a speed saturation compensation value that does not cause speed saturation; and a control system adjuster that adjusts at least one parameter of the non-interference controller, the disturbance estimator, and the speed saturation compensator based on fluctuation occurred in the hull and / or operation of the actuators.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a control device, an underwater vehicle, and a control method.

Background Art

[0002] In the operation of an underwater vehicle, it is necessary to suppress the rocking of the hull due to disturbances such as waves. Non-Patent Document 1 discloses a disturbance estimator that estimates disturbances. Non-Patent Document 2 discloses a method of estimating the state of an underwater vehicle and estimating disturbances. Further, Patent Documents 3 and 4 disclose a control device that estimates the direction, magnitude, frequency, etc. of the disturbance applied to the underwater vehicle and generates a control command such as a rudder angle that cancels out the estimated disturbance.

[0003] Also, during the operation of an underwater vehicle, when control is performed with respect to control axes related to depth, roll angle, pitch angle, azimuth angle, etc., mutual interference may occur between specific axes. For example, even if control is performed to suppress rocking for each axis, it may take time for the rocking to converge due to the influence of mutual interference. In contrast, Patent Document 1 discloses a control method that calculates a rudder angle command for compensating for the interference between axes according to the state of the hull and makes the interference force between axes non-interfering.

[0004] Also, there is a limit to the range in which the rudder of an underwater vehicle can follow changes in the rudder angle command. When a rudder angle command exceeding the limit is input, the actual rudder angle cannot be followed and speed saturation occurs. In contrast, Patent Document 2 discloses a speed saturation compensator that compensates a rudder angle command that causes speed saturation to a command value within a followable range. By using the speed saturation compensator, sudden movement of the rudder can be suppressed and the occurrence of speed saturation can be avoided.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Non-Patent Document

[0006]

Non-Patent Document 1

Non-Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0007] By compensating for disturbances based on a disturbance estimator, it is possible to suppress the rocking of the hull. However, for example, when trying to deal with rocking in the case where there are high-frequency components in the rocking, the rudder has to be operated frequently, resulting in deterioration of energy-saving performance. There is a need for control that can adjust the balance between the hull rocking suppression performance and the energy-saving performance.

[0008] The present disclosure provides a control device, an underwater vehicle, and a control method that can solve the above problems.

Means for Solving the Problems

[0009] The control device of the present disclosure includes a feedback controller that calculates a control command value based on the difference between the position of the hull and the target position, a non-interference controller that calculates a non-interference compensation value for canceling the mutual interference between the control axes of the hull, a disturbance estimator that estimates the force of the disturbance acting on the hull and calculates a disturbance compensation value for canceling the disturbance, a speed saturation compensator that calculates a speed saturation compensation value so that speed saturation does not occur when the actuator of the hull is controlled based on the control command value, and a control system adjuster that adjusts at least one parameter among the non-interference controller, the disturbance estimator, and the speed saturation compensator based on the sway generated in the hull and / or the operation of the actuator. Then, based on the result of the frequency component analysis of the rocking of the hull, the top two principal components are selected, and the frequency between the two principal components is set to the filter bands of the low-pass filter provided in the disturbance estimator and the low-pass filter provided in the non-interference controller.

[0010] The underwater vehicle of the present disclosure includes the above control device.

[0011] The control method of the present disclosure is a control method executed by a control device having a non-interference controller, a disturbance estimator, and a speed saturation compensator, and includes a step of calculating a control command value based on the difference between the position of the hull and the target position, a step in which the non-interference controller calculates a non-interference compensation value for canceling the mutual interference between the control axes of the hull, a step in which the disturbance estimator estimates the force of the disturbance acting on the hull and calculates a disturbance compensation value for canceling the disturbance, a step in which the speed saturation compensator calculates a speed saturation compensation value so that speed saturation does not occur when the actuator of the hull is controlled based on the control command value, and a step of adjusting at least one parameter among the non-interference controller, the disturbance estimator, and the speed saturation compensator based on the sway generated in the hull and / or the operation of the actuator. Then, in the step of adjusting the parameters, based on the result of the frequency component analysis of the rocking of the hull, the top two principal components are selected, and the frequency between the two principal components is set to the filter bands of the low-pass filter provided in the disturbance estimator and the low-pass filter provided in the non-interference controller.

Advantages of the Invention

[0012] According to the above control device, underwater vehicle, and control method, the balance between the sway suppression performance and the energy saving performance can be adjusted. For example, it is possible to achieve both sway suppression and energy saving performance.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Mode for Carrying Out the Invention

[0014] Hereinafter, the control system of the present disclosure will be described with reference to FIGS. 1 to 4. In the following description, the same reference numerals are given to configurations having the same or similar functions. And the overlapping descriptions of those configurations may be omitted.

[0015] (System Configuration) FIG. 1 shows a block diagram of the control system of the underwater vehicle 1. As shown in FIG. 1, the underwater vehicle 1 includes a control device 10 and a fuselage 20. The control device 10 includes an FB (feedback) controller 11, an actuator control system 12, a speed saturation compensator 13, a disturbance estimator 14, a non-interference controller 15, a control system adjuster 16, and a parameter calculation unit 17. The fuselage 20 includes actuators and sensors provided in the underwater vehicle 1.

[0016] The FB controller 11 calculates a control command value based on the difference between the position of the underwater vehicle 1 and a predetermined target position. For example, the FB controller 11 calculates a control command value for a control axis (any one of the XYZ axis directions and the directions around each axis related to the six degrees of freedom of the hull motion) such as depth, pitch angle, azimuth angle, etc. so that the position of the underwater vehicle 1 coincides with the target position by PID control or the like.

[0017] The actuator control system 12 converts the control command value calculated by the FB controller 11 into an actual command value (referred to as the actual command value) to be output to the actuator, and controls the actuator (airframe 20). The actuator is, for example, a plurality of rudders provided in the underwater vehicle 1. The actual command value is, for example, a rudder angle command for each rudder. As shown in the figure, when the speed saturation compensator 13, the disturbance estimator 14, and the non-interference controller 15 output compensation values, the control command value calculated by the FB controller 11 is compensated by those compensation values.

[0018] The speed saturation compensator 13 acquires the control command value input to the actuator control system 12 and the actual command value output from the actuator control system 12, calculates a speed saturation compensation value so that the control command value input to the actuator control system 12 does not reach speed saturation, and outputs this value. By the speed saturation compensation value, the control command value input to the actuator control system 12 is compensated so as to be within a range where the operation of the actuator can follow. As the speed saturation compensator 13 of the present embodiment, for example, a speed saturation compensation unit disclosed in Patent Document 2 can be used. Since the configuration of the speed saturation compensator 13 is disclosed in Patent Document 2, the description thereof is omitted in this specification. The speed saturation compensator 13 has a parameter called a bandwidth adjustment gain (a parameter inside the ideal model 41 in Patent Document 2) inside. When the value of this bandwidth adjustment gain is increased, it acts to more strongly suppress a sharp change in the actuator. Since the speed saturation compensator 13 has the function of suppressing a sharp operation of the actuator, it contributes to energy saving of the control. When the value of the bandwidth adjustment gain is increased, the energy saving effect is improved. The value of the bandwidth adjustment gain can be adjusted by the control system regulator 16.

[0019] The external disturbance estimator 14 acquires the actual command value output from the actuator control system 12 and information indicating the state of the underwater vehicle 1 (such as the actual steering angle, measured values of a gyro sensor and a depth gauge, etc.), estimates the external disturbance force acting on the hull, and calculates an external disturbance compensation value for canceling out the estimated external disturbance. For example, the external disturbance estimator 14 estimates the external disturbance due to waves in each direction of depth, pitch angle, and azimuth angle, and calculates an external disturbance compensation value for canceling out the external disturbance for each direction. There is no particular limitation on the external disturbance estimation method in the external disturbance estimator 14 of the present embodiment, and a known external disturbance observer or the like can be used (for example, Non-Patent Document 1). Also, for the configuration that calculates the control amount of the rudder or the like (external disturbance compensation value) necessary for canceling out the estimated external disturbance, a known controller generally adopted in an underwater vehicle can be used (for example, Patent Documents 3 and 4). Further, the external disturbance estimator 14 of the present embodiment includes a low-pass filter 141 (not shown) and an output gain 142 (not shown) which is a parameter that can be set inside. Generally, the external disturbance estimated by the external disturbance estimator 14 includes a plurality of frequency components. For example, the low-pass filter 141 is provided for each control axis, and reduces a band of a predetermined frequency or higher among the frequency components of the external disturbance in the direction of each estimated control axis. The external disturbance estimator 14 calculates an external disturbance compensation value (for example, a compensation rudder angle for the rudder corresponding to the direction of sway) for canceling out the external disturbance in the low-frequency band in the direction of each control axis that has passed through the low-pass filter 141. When the band of the frequency passing through the low-pass filter 141 is increased, sway in a wider frequency band can be suppressed, but it becomes necessary to deal with the high-frequency components of the sway, and the rudder will operate more frequently accordingly. This is disadvantageous (increased energy consumption) from the viewpoint of energy saving. The output gain 142 is a parameter for multiplying the calculated external disturbance compensation value to adjust the magnitude of the value. The external disturbance estimator 14 calculates a compensation rudder angle for each rudder (for example, a rudder for controlling the external disturbance in the depth direction, a rudder for controlling the external disturbance in the left-right direction, etc.) for dealing with the estimated external disturbances in various directions. The output gain 142 is prepared for each of these rudders and adjusts the magnitude of the external disturbance compensation value for each rudder. The value of the output gain 142 is set in the range of 0 or more and 1 or less.For example, when not dealing with disturbances, 0 is set for the output gain 142, and when canceling out disturbances as much as possible, 1 is set for the output gain 142. The band setting of the low-pass filter 141 and the value of the output gain 142 can be adjusted by the control system regulator 16.

[0020] The non-interference controller 15 compensates for the oscillation caused by the inter-axis interference between the six axes. For example, when attempting to control the depth, pitch angle, and azimuth angle of the underwater vehicle 1 to their respective desired positions, the non-interference controller 15 acquires information indicating the state of the underwater vehicle 1 (such as the actual steering angle, measured values of the gyro sensor and depth gauge, etc.), and calculates a non-interference compensation value (compensation steering angle for each rudder related to non-interference) to reduce the interference occurring between the control axes. For the non-interference controller 15, for example, a non-interference control unit disclosed in Patent Document 1 can be used. Since the configuration of the non-interference controller 15 is disclosed in Patent Document 1, the description thereof is omitted in this specification. In addition to the configuration disclosed in Patent Document 1, the non-interference controller 15 of the present embodiment includes a low-pass filter 151 (not shown) and an output gain 152 (not shown) inside. Generally, the information indicating the state of the underwater vehicle 1 acquired by the non-interference controller 15 contains a plurality of frequency components. For example, the low-pass filter 151 is provided for each control axis and reduces the band of frequencies above a predetermined frequency among the plurality of estimated frequency components in the direction of each control axis. The non-interference controller 15 calculates a non-interference compensation value that cancels out the oscillation in the low-frequency band in the direction of each control axis (oscillation caused by inter-axis interference) that has passed through the low-pass filter 151. When the band of the frequency passing through the low-pass filter 151 is increased, it becomes necessary to deal with the high-frequency components of the oscillation, and the rudder will operate more frequently accordingly, leading to an increase in energy consumption. The output gain 152 is a parameter for multiplying the non-interference compensation value to adjust its magnitude. The output gain 152 can be set for each of the plurality of rudders. The value of the output gain 152 is set within the range of 0 or more and 1 or less. The band setting of the low-pass filter 151 and the value of the output gain 152 can be adjusted by the control system regulator 16.

[0021] As shown in the figure, a second loop including a disturbance estimator 14 is configured outside the first loop composed of an actuator control system 12 and a speed saturation compensator 13. Thereby, ideally, the disturbance is canceled within the second loop. Even if oscillation is confirmed based on the information indicating the state of the underwater vehicle 1 obtained from the airframe 20, the oscillation is considered to be caused by the shaft interference. Therefore, the non-interference controller 15 is configured to be arranged in the outermost loop so that the non-interference compensation value can be calculated only for the oscillation caused by the shaft interference.

[0022] The control system adjuster 16 acquires the actual command value output from the actuator control system 12 and the information indicating the state of the underwater vehicle 1 (such as the actual steering angle, the measured values of the gyro sensor and the depth gauge) from the airframe 20, calculates the evaluation index value described below, and based on the calculated evaluation index value, changes one or more of the value of the band adjustment gain of the speed saturation compensator 13, the band setting of the low-pass filter 141 of the disturbance estimator 14, the value of the output gain 142, the band setting of the low-pass filter 151 of the non-interference controller 15, and the value of the output gain 152 as required. This process is called parameter adjustment or control system switching.

[0023] (Evaluation Index) Fig. 2 shows an example of the evaluation index calculated by the control system adjuster 16. (1) Evaluation value of the oscillation state... The control system adjuster 16 acquires the measured values of the depth gauge and the gyro sensor and calculates the Peak to Peak value (the difference between the maximum value and the minimum value of the measured values measured within a predetermined time) or the RMS value (root mean square value) of the measured values within a predetermined time for the oscillation in each control axis direction such as depth, pitch angle, and azimuth angle. The measured Peak to Peak value and RMS value for each control axis direction are the evaluation values of the oscillation state.

[0024] (2) Actuator operation evaluation value... The control system regulator 16 acquires the actual operation amount of the actuator (for example, the actual steering angle at each moment) from the underwater vehicle 1 at each moment, and calculates the total operation amount (absolute value integration) within a predetermined time and the absolute value integration of the actuator operation speed. These values are the actuator operation evaluation values.

[0025] (3) Evaluation value of the rocking frequency component... The control system regulator 16 acquires the measured values of the depth meter and gyro sensor, and performs frequency component analysis on the waveform data indicating the rocking within a predetermined time for each control axis direction by FFT (Fast Fourier Transform) or the like. The result of the frequency component analysis is the evaluation value of the rocking frequency component.

[0026] (4) Evaluation value of the actuator compensation amount... The control system regulator 16 acquires the compensation rudder angles (disturbance compensation value and non-interference compensation value respectively) output by the disturbance estimator 14 and the non-interference controller 15 at each moment, and calculates the Peak to Peak value of the compensation rudder angle. Or (alternatively, in addition to the Peak to Peak value), the control system regulator 16 performs frequency component analysis on the compensation rudder angle by FFT or the like. The Peak to Peak value of the compensation rudder angle and the result of the frequency component analysis are the evaluation values of the actuator compensation amount.

[0027] The (1) and (3) of the above evaluation index values are the evaluation index values indicating the rocking of the underwater vehicle 1, and the (2) and (4) related to the actuator operation are the evaluation index values of the energy-saving performance. The control system regulator 16 uses these evaluation index values to adjust the parameters of the disturbance estimator 14 and the non-interference controller 15 so that the rocking suppression and energy saving of the underwater vehicle 1 can be achieved simultaneously. Also, as will be described below, the control system regulator 16 has a function of switching and executing a control mode that emphasizes rocking suppression and a control mode that emphasizes energy saving on the premise of achieving both rocking suppression and energy saving, and adjusts the parameters (low-pass filter band, output gain, etc.) of each compensator (speed saturation compensator 13, disturbance estimator 14, non-interference controller 15) according to the purpose of control.

[0028] (Timing of switching the control system) The control system adjuster 16 automatically switches (parameter adjustment) the control system at regular intervals (for example, every 5 minutes, 10 minutes, etc.). Or, the control system adjuster 16 automatically switches the control system at the timing of switching the operation mode of the underwater vehicle 1 (for example, navigation and mooring), switching the control objective (emphasis on sway suppression or emphasis on energy saving), or when the sea area is changed. Or, the control system adjuster 16 switches the control system by manual operation of the user. Note that since the period of swaying due to waves, etc. is generally several seconds to several tens of seconds, when automatically switching the control system, the control system is switched at a period longer than the swaying period, rather than the calculation period of the control device 10.

[0029] (Control system switching) Fig. 3 shows an overview of the parameters to be adjusted when switching the control system of the present embodiment. (A) Regardless of the control objective, the control system adjuster 16 adjusts the filter bandwidths of the low-pass filter 141 of the disturbance estimator 14 and the low-pass filter 151 of the non-interference controller 15. (A1) The control system adjuster 16 identifies, for the oscillation in each control axis direction, the first principal component f1 and the second principal component f2, which are the top two components with large peak values among the frequency components constituting the oscillation, based on the evaluation index value "(3) evaluation value of the oscillation frequency component". Here, it is assumed that the frequencies of the first principal component f1 and the second principal component f2 have the relationship f1 < f2. The control system adjuster 16 sets the filter bandwidths (and approximate differentiation bandwidths) f of the low-pass filters 141 and 151 for each control axis to be f1 < f < f2 based on the high-low relationship of the frequencies, regardless of the magnitude relationship of the peak values of f1 and f2. Here, f1 is the lowest-frequency component among the main frequency components constituting the hull oscillation. In the operation of the underwater vehicle 1, the influence of the low-frequency component f1 is the most dominant, and by setting the filter bandwidth f as described above, a compensation value (compensation rudder angle) for dealing with this low-frequency component can be calculated. Also, when dealing with the oscillation of f2 with a higher frequency than f1, although the oscillation suppression effect is improved (compared to that effect), the operation amount of the actuator (rudder) increases and the energy consumption increases. Therefore, by setting the bandwidths of the low-pass filters 141 and 151 for each control axis to f, which is lower in frequency than f2, the frequency component of f2 is blocked so that the operation of the actuator does not become excessive. By adjusting the filter bandwidth f of the low-pass filters 141 and 151 according to the frequency components of the actual oscillation in this way, both oscillation suppression and energy saving are achieved.

[0030] Note that the method of setting the filter bandwidth f is arbitrary. For example, the control system adjuster 16 may set f to the average value of f1 and f2, or may set f to a value shifted by a predetermined value toward the f1 side or the f2 side from the average value. Alternatively, the control system adjuster 16 may store a table or function defining the relationship between f1, f2, and f, and set f based on f1 and f2 of the FFT result and the previously defined table.

[0031] (A2) As another method, the control system adjuster 16 may identify the first principal component f1 and the second principal component f2 from the result of frequency component analysis of the estimated disturbance value estimated by the disturbance estimator 14, and set the filter band f satisfying f1 < f < f2 in the low-pass filters 141 and 151 for each control axis.

[0032] In addition to setting the filter bands of the low-pass filters 141 and 151, the control system adjuster 16 adjusts parameters according to the control objective.

[0033] (When the control objective emphasizes roll suppression) (B) The control system adjuster 16 turns on both the disturbance estimator 14 and the non-interference controller 15. That is, the control system adjuster 16 sets the values of the output gain 142 and the output gain 152 to 1. Thereby, both the roll caused by the disturbance and the roll caused by the interference between the control axes are suppressed, and the roll of the underwater vehicle 1 is suppressed.

[0034] (When the control objective emphasizes energy saving) (C) The control system adjuster 16 adjusts the output gain 142 of the disturbance estimator 14 and the output gain 152 of the non-interference controller 15 between 0 and 1 based on the frequency of the roll, the frequency of the compensation rudder angle, the magnitude of the compensation rudder angle, etc.

[0035] (C1) When the oscillation becomes high frequency, the control system regulator 16 sets the output gain 152 of the non-interference controller 15 for the actuator corresponding to the oscillation to a value less than 1. The case where the oscillation becomes high frequency is the case where the peak value of f2 among the above-mentioned first principal component f1 and second principal component f2 obtained from the evaluation index value "(3) Evaluation value of the oscillation frequency component" becomes equal to or greater than a predetermined threshold value. When the oscillation becomes high frequency, it is known that oscillation often occurs due to compensation for the axial interference. Therefore, the output gain 152 of the non-interference controller 15 is decreased to reduce the adverse effect of the non-interference control. For example, regarding the oscillation in the depth direction (vertical direction), when the peak value of f2 exceeds the threshold value, the value of the output gain 152 for the compensation rudder angle to the rudder used for the depth direction control is set to less than 1. Note that the specific value of the output gain 152 may be, for example, by creating a table in advance that defines the relationship between the frequency and peak value of f2 and the output gain 152, and based on the principal component f2 of the frequency component analysis result of the oscillation measured during a predetermined period (for example, 5 minutes or 10 minutes) immediately before adjusting the value of the output gain 152 and the table created in advance, the output gain 152 may be set.

[0036] (C2) Based on the evaluation index value "(4) Evaluation value of the actuator compensation amount", the control system regulator 16 identifies the top two main frequency components f1 and f2 (f1 < f2) for each of the disturbance compensation value output by the disturbance estimator 14 and the non-interference compensation value output by the non-interference controller 15 in the same way as in the case of oscillation. Then, the control system regulator 16 sets the output gain of the compensator with the larger peak value among f2 of the disturbance compensation value and f2 of the non-interference compensation value to a value less than 1 (for example, 0 may also be acceptable). For example, for a certain control axis direction (for example, depth), when the principal component f2 of the disturbance compensation value calculated is f2 14 and the principal component f2 of the non-interference compensation value is f2 15 and the peak value of f2 14 < the peak value of f2 15 holds, a value less than 1 is set for the output gain 152. Conversely, when the peak value of f2 14 > the peak value of f2 15If the peak value is established, a value smaller than 1 is set for the output gain 142. The specific values of the output gain 142 and the output gain 152 are determined based on, for example, a table showing the relationship between the frequency and peak value of f2 and the magnitude of the output gain, which are individually determined in advance for the disturbance estimator 14 and the non-interference controller 15 respectively. Thereby, the compensation value that causes frequent operation of the rudder can be made small or zero, and the energy-saving performance can be improved.

[0037] (C3) The control system adjuster 16 sets the output gain of the larger value among the disturbance compensation value (for example, the integral of the absolute value of the compensation rudder angle) output by the disturbance estimator 14 and the non-interference compensation value (the integral of the absolute value of the compensation rudder angle) output by the non-interference controller 15 based on the evaluation index value "(2) actuator operation evaluation value" in the same manner as in the case of (C2). For example, if the disturbance compensation value > the non-interference compensation value, the control system adjuster 16 sets a value smaller than 1 for the output gain 142, and if the disturbance compensation value > the non-interference compensation value, the control system adjuster 16 sets a value smaller than 1 for the output gain 152. By suppressing the operation of the compensator that contributes to the increase in actuator operation, the energy-saving performance can be improved.

[0038] (C4) During operation with an emphasis on energy saving, when the azimuth angle or roll angle of the hull fluctuates by a certain threshold value or more based on the evaluation index value "(1) sway evaluation value", the control system adjuster 16 automatically sets the output gain 152 of the non-interference controller 15 to 1. When the azimuth angle or roll angle changes significantly, it means that waves are entering the hull from the side. In this case, since the control for the sway (disturbance) of the azimuth angle and roll angle interferes with the control of the depth and pitch angle, when the lateral sway exceeds a certain threshold value, the non-interference control is automatically turned on.

[0039] (C5) During operation with an emphasis on energy conservation, based on the evaluation index value "(2) Actuator operation evaluation value", when the evaluation index value (for example, the absolute value integral of the actuator operation speed) is equal to or greater than a predetermined threshold, the control system regulator 16 changes the parameters (bandwidth adjustment gain) of the speed saturation compensator 13 based on a predetermined table that defines the relationship between the evaluation index value and the bandwidth adjustment gain. For example, in a situation where the actuator operation is large, the energy conservation performance can be improved by increasing the bandwidth adjustment gain.

[0040] The parameter calculation unit 17 creates a table for determining the values of various parameters to be adjusted during the switching of the control system by the control system regulator 16. The parameter calculation unit 17 includes a disturbance information storage unit 171 and a simulation evaluation unit 172. The disturbance information storage unit 171 acquires and stores disturbance information (disturbance waveform data) indicating the disturbances in each control axis direction estimated by the disturbance estimator 14 with the output gain 142 set to 0 during the operation of the underwater vehicle 1. The simulation evaluation unit 172 has a hull model that simulates the operation and state of the underwater vehicle 1, and can calculate the sway when a disturbance is applied to the underwater vehicle 1 and the state of the underwater vehicle 1 when control is performed by setting arbitrary values for the parameters of each compensator. The simulation evaluation unit 172 inputs the disturbance information stored in the disturbance information storage unit 171 into the hull model and simulates the sway when the same disturbance as the disturbance information is applied to the underwater vehicle 1. Further, the simulation evaluation unit 172 uses the hull model to perform a control simulation when operating the underwater vehicle 1 by setting various values for each of the band adjustment gain of the speed saturation compensator 13, the filter band and output gain 142 of the low-pass filter 141 of the disturbance estimator 14, and the filter band and output gain 152 of the low-pass filter 151 of the non-interference controller 15 with respect to the simulated sway, and evaluates the values set for each parameter. The simulation evaluation unit 172 calculates the evaluation index values of the above (1) to (4) from the information on the sway and actuator operation calculated during the control simulation, and calculates, for example, the time until the sway converges (for example, the time until the peak to peak value becomes less than or equal to the threshold value) based on the “(1) evaluation value of the sway state”, and calculates the operation amount of the actuator during control execution based on the “(2) actuator operation evaluation value”, and selects the values of the parameters when each satisfies a predetermined standard. The simulation evaluation unit 172 selects the values of each parameter for each piece of disturbance information stored in the disturbance information storage unit 171 and registers the results in a table. For example, the simulation evaluation unit 172 creates a table defining the relationship between the main components f1, f2 and the filter band f of the low-pass filters 141, 151 for the switching (A1) of the control system, a table defining the values of the main component f2 and the output gain 152 for (C1), and so on. The simulation evaluation unit 172 may perform a control simulation for each speed of the underwater vehicle 1 and create each table. Then, the parameter calculation unit 17 outputs the table created by the simulation evaluation unit 172 to the control system adjuster 16. The control system adjuster 16 performs parameter adjustment for the above-described switching (A1) to (C5) of the control system based on the table created by the simulation evaluation unit 172.It is difficult to prepare a parameter table in advance assuming all types of disturbances. On the other hand, for example, in the same sea area, there is a high possibility that disturbances similar to those observed (actually estimated by the disturbance estimator 14) at a predetermined time occur steadily. According to the parameter calculation unit 17, control can be performed using appropriate parameter values for disturbances corresponding to the waves in the sea area where the underwater vehicle 1 is actually navigating.

[0041] (Operation) Next, the operation of the control device 10 will be described. FIG. 4 is a flowchart showing an example of the operation of the control system according to the embodiment. The underwater vehicle 1 is in operation, and it is assumed that the user (operator) has previously instructed the control device 10 about the control mode (emphasis on swing suppression, emphasis on energy saving). The control device 10 determines whether to create a table (step S1). The user makes a judgment on whether to create a table, and if creating, inputs that fact to the control device 10, and based on this input, the control device 10 makes the determination in step S1. For example, when the user believes that the change in waves is large due to a change in the sea area or a change in sea conditions, etc., the user inputs a table creation instruction to the control device 10 in order to obtain disturbance information due to actual waves. If it is considered that the (standard) table stored in advance by the control system adjuster 16 can be used to handle the situation, the user does not give a table creation instruction. When a table creation instruction is input, the control device 10 determines to create a table. Otherwise (step S1; No), the process proceeds to the process of step S5.

[0042] When it is determined that a table is to be created (step S1; Yes), first, the control system adjuster 16 sets 0 to the output gain 142. In the disturbance estimator 14, the disturbance estimation process continues even after the output gain 142 becomes 0. The disturbance estimator 14 acquires measurement values measured by a depth gauge that measures the swing in the depth direction and a gyro sensor that detects the swing of the pitch angle and azimuth angle at every moment, and performs disturbance estimation for each control axis direction (step S2). The disturbance estimator 14 outputs the estimated disturbance information to the parameter calculation unit 17. The disturbance information storage unit 171 acquires and stores the disturbance information from the disturbance estimator 14. The disturbance information storage unit 171 may store the speed of the underwater vehicle 1 and the disturbance information in association with each other. When the collection of the disturbance information is completed, the control system adjuster 16 sets 1 to the output gain 142. Next, the simulation evaluation unit 172 gives the estimated disturbance information to the hull model, performs a control simulation while setting various values for various parameters, and determines appropriate parameters in association with the evaluation index values used in the control system switching (A1) to (C5) (step S3). Next, the simulation evaluation unit 172 creates a table in which the determined parameters are registered (step S4). The table is created for each parameter set in the control system switching (A1) to (C5). For example, for the control system switching (A2), within the range of the actually observed (estimated) disturbance, a table associating the main components f1 and f2 for each disturbance with the filter band f of the low-pass filter 141 and a table associating the main components f1 and f2 with the filter band f of the low-pass filter 151 are created. For the control system switching (C3), a table in which the values of the output gain 142 and the output gain 152 that can most prevent the decrease in the energy-saving performance obtained in the control simulation for the actually observed (estimated) disturbance are registered is created.

[0043] When the table is created or when the table is not created, the control system adjuster 16 acquires measurement values of sensors from the aircraft 20 and calculates the evaluation index values of (1) to (4) above (step S5). For example, the control system adjuster 16 calculates the evaluation index values of each of (1) to (4) over a certain period (such as 10 minutes). Next, the control system adjuster 16 adjusts the filter bandwidth f of the low-pass filters 141 and 151 (either (A1) or (A2) of the control system switching) based on the calculated evaluation index values (step S6). Next, the control system adjuster 16 performs parameter adjustment according to the control objective based on the calculated evaluation index values (step S7). For example, when the control objective emphasizes oscillation, the control system adjuster 16 performs (B) of the control system switching. When the control objective emphasizes energy saving, the control system adjuster 16 performs (C1) to (C5) of the control system switching.

[0044] The control system adjuster 16 executes the processes of steps S6 and S7 every certain period (such as 10 minutes). Alternatively, the control system adjuster 16 executes the processes of steps S6 and S7 at the timing when the operation mode, control objective, sea area is changed, or at the timing instructed by the user. The control device 10 repeatedly performs the processes of steps S1 to S7.

[0045] Note that the control objective can be set manually by the user or automatically by the control system adjuster 16 based on the evaluation index values of (1) to (4). For example, when the total time that the Peak to Peak value of the “(1) evaluation value of the oscillation state” exceeds the threshold during the control emphasizing energy saving becomes longer than the predetermined time, the control system adjuster 16 may switch the control mode to emphasize oscillation suppression. Alternatively, when the total time that the “(2) actuator operation evaluation value” exceeds the threshold during the control emphasizing oscillation suppression becomes longer than the predetermined time, the control system adjuster 16 may switch the control mode to emphasize energy saving.

[0046] (Effect) As described above, according to the present embodiment, the disturbance estimator 14 directly compensates for the disturbance, the non-interference controller 15 suppresses the generation of rocking among the interference characteristics of the hull, and the speed saturation compensator 13 suppresses the steep operation of the actuator, and by operating them in an appropriate balance according to the rocking state, it is possible to achieve both the contradictory events of rocking suppression and reduction of actuator operation (energy saving). Further, the balance between the rocking suppression performance and the energy saving performance can be arbitrarily adjusted.

[0047] The above-described control device 10 is implemented in a computer including a processor such as a CPU (Central Processing Unit), a main storage device, an auxiliary storage device, etc., and each of the above-described functions is realized by the processor executing a program stored in the auxiliary storage device. The processor secures a storage area in the main storage device according to the program. The processor secures a storage area in the auxiliary storage device for storing the data being processed according to the program. Note that part or all of each process of the control device 10 may be executed by hardware such as LSI (Large Scale Integration), ASIC (Application Specific Integrated Circuit), FPGA (Field-Programmable Gate Array).

[0048] As described above, several embodiments according to 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, replacements, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, as well as in the invention described in the claims and the equivalent scope thereof.

[0049] <Supplementary Note> The control device, the underwater vehicle, the control method, and the program described in each embodiment are understood as follows, for example.

[0050] (1) The control device 10 according to the first aspect includes a feedback controller 11 that calculates a control command value based on the difference between the position of the hull and the target position, a non-interference controller 15 that calculates a non-interference compensation value for canceling the mutual interference between the control axes of the hull, a disturbance estimator 14 that estimates the force of the disturbance acting on the hull and calculates a disturbance compensation value for canceling the disturbance, a speed saturation compensator 13 that calculates a speed saturation compensation value such that speed saturation does not occur when the actuator of the hull is controlled based on the control command, and a control system adjuster 16 that updates at least one parameter among the non-interference controller, the disturbance estimator, and the speed saturation compensator based on the swing generated in the hull and / or the operation of the actuator. Thereby, the balance between the swing suppression performance and the energy saving performance can be adjusted.

[0051] (2) The control device 10 according to the second aspect is the control device of (1), and includes a first control loop including the speed saturation compensator that compensates the control command with the speed saturation compensation value, a second control loop including the disturbance estimator that gives the control command compensated with the disturbance compensation value to the first control loop, and a third control loop including the non-interference controller that gives the control command compensated with the non-interference compensation value to the second control loop. Thereby, the interference between the control axes can be appropriately made non-interfering, and as a result, the disturbance can be effectively suppressed.

[0052] (3) The control device according to the third aspect is the control device of (1) to (2), and based on the result of the frequency component analysis of the swing of the hull, selects the top two main components and sets the frequency between the two main components to the filter band of the low-pass filter provided in the disturbance estimator and the low-pass filter provided in the non-interference controller. Thereby, it is possible to achieve both the swing suppression and the reduction (energy saving) of the actuator operation, which are conflicting events.

[0053] (4) The control device according to the fourth aspect is the control device of (1) to (3), and when the control purpose is swing suppression, the control system adjuster sets the value of the output gain provided in the disturbance estimator and the value of the output gain provided in the non-interference controller to 1. Thereby, the swing can be suppressed.

[0054] (5) The control device according to the fifth aspect is the control device of (1) to (4), and when the control purpose is energy saving, the control system adjuster sets a value smaller than 1 to the value of the output gain provided in the disturbance estimator or the value of the output gain provided in the non-interference controller. Thereby, the actuator operation can be suppressed.

[0055] (6) The control device according to the sixth aspect is the control device of (5), and when the control purpose is energy saving, the control system adjuster selects the top two main components based on the result of the frequency analysis of the swing of the hull, and when the frequency of the component with the higher frequency among them is equal to or higher than the threshold value, the control system adjuster sets a value smaller than 1 to the value of the output gain provided in the non-interference controller. Excessive actuator operation due to the influence of the compensation value output by the non-interference controller can be suppressed.

[0056] (7) The control device according to the seventh aspect is the control device of (5) to (6), and when the control purpose is energy saving, when the high-frequency component of the disturbance compensation value is larger than the high-frequency component of the non-interference compensation value or the disturbance compensation value is larger than the non-interference compensation value, the control system adjuster sets a value smaller than 1 to the value of the output gain of the disturbance estimator, and when the high-frequency component of the non-interference compensation value is larger than the high-frequency component of the disturbance compensation value or the non-interference compensation value is larger than the disturbance compensation value, the control system adjuster sets a value smaller than 1 to the value of the output gain of the non-interference controller. Thereby, the influence of the compensation value that causes the actuator operation to increase can be reduced, and the energy saving performance can be improved.

[0057] (8) The control device according to the eighth aspect is the control device of (5) to (7), and when the control target is energy saving and the azimuth angle or roll angle of the hull is oscillating above a predetermined threshold value, the control system regulator sets the output gain of the non-interference controller to 1. In a situation where shaft interference occurs, even under control aimed at energy saving, the non-interference controller is turned on to suppress shaft interference.

[0058] (9) The control device according to the ninth aspect is the control device of (1) to (8), and when improving energy-saving control, the control system regulator adjusts the parameters of the speed saturation compensator so that the action of compensating for speed saturation becomes stronger. Thereby, the steep operation of the actuator can be suppressed, and the energy-saving performance can be improved.

[0059] (10) The control device according to the tenth aspect is the control device of (1) to (9), and based on the disturbance estimated by the disturbance estimator, it calculates the oscillation occurring in the hull, and while setting various values for at least one of the parameters of the non-interference controller, the disturbance estimator, and the speed saturation compensator, it executes a simulation for controlling the hull with respect to the calculated oscillation, and based on the simulation result, it evaluates the values of the parameters and determines a parameter calculation unit that determines a value that satisfies a predetermined criterion among the variously set values of the parameters. Thereby, appropriate values can be set for the parameters of the non-interference controller, the disturbance estimator, and the speed saturation compensator.

[0060] (11) The underwater vehicle according to the eleventh aspect includes the control device according to any one of (1) to (10).

[0061] (12) The control method according to the twelfth aspect is a control method executed by a control device having a non-interference controller, a disturbance estimator, and a speed saturation compensator, the method including steps of calculating a control command value based on a difference between a position of a hull and a target position; calculating, by the non-interference controller, a non-interference compensation value for canceling mutual interference between control axes of the hull; estimating, by the disturbance estimator, a disturbing force acting on the hull and calculating a disturbance compensation value for canceling the disturbance; calculating, by the speed saturation compensator, a speed saturation compensation value such that speed saturation does not occur when the actuator of the hull is controlled based on the control command value; and adjusting at least one parameter among the non-interference controller, the disturbance estimator, and the speed saturation compensator based on the swing occurring in the hull and / or the operation of the actuator.

Description of Signs

[0062] 1 ··· Underwater vehicle, 10 ··· Control device, 11 ··· FB controller, 12 ··· Actuator control system, 13 ··· Speed saturation compensator, 14 ··· Disturbance estimator, 15 ··· Non-interference controller, 16 ··· Control system adjuster, 17 ··· Parameter calculation unit, 171 ··· Disturbance information storage unit, 172 ··· Simulation evaluation unit

Claims

1. A feedback controller that calculates a control command value based on the difference between the position of the hull and the target position, A non-interference controller that calculates a non-interference compensation value for canceling the mutual interference between the control axes of the hull, A disturbance estimator that estimates the force of the disturbance acting on the hull and calculates a disturbance compensation value for canceling the disturbance, A speed saturation compensator that calculates a speed saturation compensation value so that speed saturation does not occur when controlling the actuator of the hull based on the control command value, A control system adjuster that adjusts at least one parameter among the non-interference controller, the disturbance estimator, and the speed saturation compensator based on the rocking of the hull and / or the operation of the actuator, having, Based on the result of the frequency component analysis of the rocking of the hull, the top two main components are selected, and the frequency between the two main components is set to the filter band of the low-pass filter provided in the disturbance estimator and the low-pass filter provided in the non-interference controller, A control device.

2. A feedback controller that calculates a control command value based on the difference between the position of the hull and the target position, A non-interference controller that calculates a non-interference compensation value for canceling the mutual interference between the control axes of the hull, A disturbance estimator that estimates the force of the disturbance acting on the hull and calculates a disturbance compensation value for canceling the disturbance, A speed saturation compensator that calculates a speed saturation compensation value so that speed saturation does not occur when controlling the actuator of the hull based on the control command value, A control system adjuster that adjusts at least one parameter among the non-interference controller, the disturbance estimator, and the speed saturation compensator based on the rocking of the hull and / or the operation of the actuator, having, When the control objective is roll suppression, the control system adjuster sets the value of the output gain provided in the disturbance estimator and the output gain of the non-interference controller to 1, Control device.

3. A feedback controller that calculates a control command value based on the difference between the position of the hull and the target position, A non-interference controller that calculates a non-interference compensation value for canceling the mutual interference between the control axes of the hull, A disturbance estimator that estimates the force of the disturbance acting on the hull and calculates a disturbance compensation value for canceling the disturbance, A speed saturation compensator that calculates a speed saturation compensation value so that speed saturation does not occur when the actuator of the hull is controlled based on the control command value, A control system adjuster that adjusts at least one parameter among the non-interference controller, the disturbance estimator, and the speed saturation compensator based on the sway generated in the hull and / or the operation of the actuator, having When the control objective is energy saving, the control system adjuster sets a value smaller than 1 for the output gain of the disturbance estimator or the output gain of the non-interference controller, Control device.

4. The control system adjuster selects the top two main components based on the result of the frequency analysis of the sway of the hull, and when the frequency of the component with the higher frequency is equal to or higher than the threshold value, sets a value smaller than 1 for the output gain of the non-interference controller. The control device according to claim 3.

5. When the peak value of the high-frequency component of the disturbance compensation value is larger than the peak value of the high-frequency component of the non-interference compensation value or the disturbance compensation value is larger than the non-interference compensation value, the control system adjuster sets a value smaller than 1 for the output gain of the disturbance estimator. When the peak value of the high-frequency component of the non-interference compensation value is larger than the peak value of the high-frequency component of the disturbance compensation value or the non-interference compensation value is larger than the disturbance compensation value, the control system adjuster sets a value smaller than 1 for the output gain of the non-interference controller. The control device according to claim 3 or claim 4.

6. When the azimuth angle or roll angle of the hull oscillates above a predetermined threshold value, the control system adjuster sets the output gain of the non-interference controller to 1. The control device according to any one of claims 3 to 5.

7. When improving energy-saving control, the control system adjuster adjusts the parameters of the speed saturation compensator so that the function of compensating for speed saturation becomes stronger. The control device according to any one of claims 1 to 6.

8. Based on the disturbance estimated by the disturbance estimator, the oscillation generated in the hull is calculated, and while various values are set for at least one of the parameters of the non-interference controller, the disturbance estimator, and the speed saturation compensator, a simulation is executed to control the hull with respect to the calculated oscillation, and based on the result of the simulation, the values of the parameters are evaluated, and among the variously set values of the parameters, a parameter calculation unit that determines a value that satisfies a predetermined criterion. The control device according to any one of claims 1 to 7, further comprising the above.

9. A first control loop including the speed saturation compensator that compensates the control command value with the speed saturation compensation value, a second control loop including the disturbance estimator that gives the control command value compensated by the disturbance compensation value to the first control loop, and a third control loop including the non-interference controller that gives the control command value compensated by the non-interference compensation value to the second control loop. The control device according to any one of claims 1 to 8, having the above.

10. An underwater vehicle including the control device according to any one of claims 1 to 9.

11. A control method executed by a control device having a non-interference controller, a disturbance estimator, and a speed saturation compensator, comprising: A step of calculating a control command value based on the difference between the position of the hull and the target position. The step of the non-interference controller calculating a non-interference compensation value for canceling mutual interference between control axes of the hull; The step of the disturbance estimator estimating a force of a disturbance acting on the hull and calculating a disturbance compensation value for canceling the disturbance; The step of the speed saturation compensator calculating a speed saturation compensation value such that speed saturation does not occur when controlling an actuator of the hull based on the control command value; The step of adjusting at least one parameter among the non-interference controller, the disturbance estimator, and the speed saturation compensator based on the rocking of the hull and / or the operation of the actuator; having; In the step of adjusting the parameter, based on the result of frequency component analysis of the rocking of the hull, two upper main components are selected, and the frequency between the two main components is set to the filter band of a low-pass filter provided in the disturbance estimator and a low-pass filter provided in the non-interference controller; A control method.

12. A control method executed by a control device having a non-interference controller, a disturbance estimator, and a speed saturation compensator, The step of calculating a control command value based on the difference between the position of the hull and the target position; The step of the non-interference controller calculating a non-interference compensation value for canceling mutual interference between control axes of the hull; The step of the disturbance estimator estimating a force of a disturbance acting on the hull and calculating a disturbance compensation value for canceling the disturbance; The step of the speed saturation compensator calculating a speed saturation compensation value such that speed saturation does not occur when controlling an actuator of the hull based on the control command value; The step of adjusting at least one parameter among the non-interference controller, the disturbance estimator, and the speed saturation compensator based on the rocking of the hull and / or the operation of the actuator; having; In the step of adjusting the parameter, When the control objective is swing suppression, set the value of the output gain included in the disturbance estimator and the output gain of the non-interference controller to 1, When the control objective is energy saving, set a value smaller than 1 for the value of the output gain included in the disturbance estimator or the output gain of the non-interference controller, Control method.

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