JP7114427B2 - Control device, its control method, control program, structure - Google Patents

Description

The present invention relates to a control device, its control method, control program, and structure.

Motion characteristics of structures such as underwater vehicles are generally nonlinear. Therefore, it is necessary to linearize the nonlinear characteristics in order to improve the control accuracy. As a linearization method, for example, there is a method of linear approximation in the vicinity of the equilibrium point (for example, Patent Document 1).

In addition, a strict linearization method has been proposed as a method of linearizing in the entire region without approximating the nonlinear characteristics of the controlled object (for example, Non-Patent Documents 1 to 4). Using a strict linearization method can be expected to improve control accuracy.

JP 2016-78621 A

Tatsutaro Ishijima, Koshu Shima, Yoshihisa Isurugi, Yutaka Yamashita, Mitsuji Mihira, Atsushi Watanabe, "Nonlinear System Theory", The Society of Instrument and Control Engineers, 1993 Mitsuji Mitsuhira, "Exact Linearization and Its Application to Trajectory Control of Traction Vehicles", Measurement and Control, Vol. 31, No. 8, 1992 Hidemitsu Yamada, "Application of Rigorous Linearization Method to Autopilot", Kansai Shipbuilders Association, No. 235, 2001 Kenichi Saito, "Strict linearization of nonlinear equations of aircraft and their control", Journal of Japan Aerospace Society, Vol. 46, No. 531, 1998

However, in a strict linearization approach, commands for each control axis (eg, commands for actuators) may interfere with each other. For example, in an underwater vehicle, a command for depth and a command for pitch angle interfere with each other, and the pitch angle automatically changes when the depth is changed. If the commands for each control axis interfere with each other, as in the exact linearization approach, saturation of the command for one control axis may result in inappropriate commands for the other interfering control axes. For example, if the command value for the depth actuator is greater than or equal to the limit value of the depth actuator, the actual depth actuator is driven with the limit value as the upper limit. On the other hand, the command value for the pitch angle actuator is determined on the premise that the depth actuator operates with a command value (command equal to or greater than the limit value). Therefore, even though the depth actuator does not operate according to the command value, the pitch angle actuator operates on the premise that the depth actuator operates according to the command value, resulting in excessive pitch angle control. It is possible that If the pitch angle is over-controlled, the depth control response (response to the target value) may decrease.

The present invention has been made in view of such circumstances, and provides a control device, control method, control program, and structure capable of suppressing excessive control due to interference between control axes. With the goal.

A first aspect of the present invention is a conversion unit that calculates a plurality of command values corresponding to each of the plurality of control parameters based on a plurality of input values corresponding to each of the plurality of control parameters, and outputs the command values to a controlled object. a deviation calculation unit for calculating a deviation between the predetermined command value and the threshold when a predetermined command value among the plurality of command values is equal to or greater than a predetermined threshold; an input correction unit that corrects at least one of the input values corresponding to the other control parameters having coherence with the control parameter corresponding to the command value using a correction value calculated using the deviation; is a control device comprising:

According to the above configuration, even if the command values corresponding to the respective control parameters interfere with each other, the input value for calculating the command value is corrected based on the deviation between the command value and the threshold value. Therefore, for example, it is possible to suppress the interference between the control parameters by considering the saturation (limit value) of the drive amount of the actuator or the like to which the command value is input.
Furthermore, according to the above configuration, since the input value of the control parameter that has interference with the control parameter corresponding to the command value that is equal to or greater than the threshold is corrected, the influence of the interference between the control parameters can be suppressed. can be done.

For example, if the control parameters are depth and pitch angle, and the depth command value is greater than or equal to a predetermined threshold value, the depth command value may exceed the limit value of the target device such as the input actuator. . In such a case, the target device cannot be driven above the limit value, and the depth command value is not fully reflected. However, since the pitch angle command value that interferes with the depth command value cannot consider the limit value of the target device, the command value is calculated assuming that the target device is driven by the depth command value. Therefore, there is a possibility that the pitch angle command value will be inappropriate (excessive control).

Therefore, when the command value is equal to or greater than a predetermined threshold value, the input value corresponding to the control parameter other than the control parameter corresponding to the command value equal to or greater than the threshold value is corrected based on the deviation between the command value and the threshold value. did. Therefore, for example, it is possible to modify the command value of each control parameter in consideration of the threshold value of the command value, such as the limit value of the target device.

In addition, since the input value corresponding to the control parameter other than the control parameter corresponding to the command value that is equal to or higher than the threshold is corrected, the control parameter corresponding to the command value that is equal to or higher than the threshold is controlled at the maximum capacity while preventing interference. Command values of other received control parameters can be corrected.

That is, even if there is interference between the command values of the control parameters, it is possible to suppress excessive control due to interference without deteriorating responsiveness, thereby improving stability and suppressing power consumption.

The above control device includes a linearization feedback unit for strictly linearizing the nonlinear characteristics of the controlled object, and the conversion unit performs strict linearization of the nonlinear characteristics on the input side of the controlled object. It is also possible to perform input value conversion for

According to the configuration described above, by using a strict linearization technique, linearization can be performed without approximating the nonlinear characteristics of the controlled object, and control accuracy can be improved.

In the control device, the input correction unit subtracts the correction value from at least one of the input values corresponding to the control parameters other than the control parameter corresponding to the command value equal to or greater than the threshold. You can do it.

According to the above configuration, since the input value corresponding to the control parameter other than the control parameter corresponding to the command value that is equal to or greater than the threshold is corrected by subtracting the correction value, the command value that is equal to or greater than the threshold It is possible to suppress excessive control due to interference with the

In the control device described above, the input correction unit may have characteristics opposite to the input/output characteristics of the conversion unit, and the correction value based on the deviation may be calculated using the characteristics opposite to those of the conversion unit.

According to the configuration as described above, it is possible to calculate the correction value corresponding to the input value, and to perform the correction more stably.

In the control device described above, the threshold value may be set based on a maximum rated value of the target device to be controlled to which the command value is input.

According to the above configuration, by determining the threshold value based on the maximum rated value of the target device to be controlled to which the command value is input, the command value exceeding the threshold interferes with excessive control. You can prevent it from happening.

A second aspect of the present invention is a structure comprising the control device described above.

A third aspect of the present invention is a conversion step of calculating a plurality of command values corresponding to each of the plurality of control parameters based on a plurality of input values corresponding to each of the plurality of control parameters, and outputting the command values to a controlled object. a deviation calculating step of calculating a deviation between the predetermined command value and the threshold when a predetermined command value among the plurality of command values is equal to or greater than a predetermined threshold; an input correction step of correcting at least one of the input values corresponding to the other control parameters having coherence with the control parameter corresponding to the command value using a correction value calculated using the deviation; is a control method including

A fourth aspect of the present invention is a conversion process of calculating a plurality of command values corresponding to each of the plurality of control parameters based on a plurality of input values corresponding to each of the plurality of control parameters and outputting them to a controlled object. a deviation calculation process for calculating a deviation between the predetermined command value and the threshold when a predetermined command value among the plurality of command values is equal to or greater than a predetermined threshold; an input correction process for correcting at least one of the input values corresponding to the other control parameters having coherence with the control parameter corresponding to the command value using a correction value calculated using the deviation; is a control program for causing a computer to execute

ADVANTAGE OF THE INVENTION According to this invention, it is effective in the ability to suppress the excessive control by the interference between each control axis.

1 is a diagram illustrating an underwater vehicle provided with a control device according to an embodiment of the present invention; FIG. FIG. 2 is a functional block diagram showing functions provided by a control device according to one embodiment of the present invention; FIG. 4 is a diagram showing an example of the motion of the underwater vehicle; FIG. 2 illustrates an example of a system applying the rigorous linearization technique; FIG. 4 shows an example of the transfer function of a system applying the exact linearization technique; FIG. 2 illustrates an example of a system applying the rigorous linearization technique; It is the figure which showed the time change of the depth in the control apparatus which concerns on one Embodiment of this invention. FIG. 4 is a diagram showing temporal changes of a depth actuator in a control device according to an embodiment of the present invention; It is the figure which showed the time change of the pitch angle in the control apparatus which concerns on one Embodiment of this invention. FIG. 4 is a diagram showing temporal changes of a pitch angle actuator in the control device according to the embodiment of the present invention; FIG. 4 is a diagram illustrating a control system in Reference Example 1; FIG. 7 is a diagram illustrating a control system in Reference Example 2; FIG. 4 is an enlarged view showing the change over time of the pitch angle in the control device according to the embodiment of the present invention; FIG. 4 is an enlarged view showing a change over time of a pitch angle actuator in the control device according to the embodiment of the present invention;

An embodiment of a control device, a control method thereof, a control program, and a structure according to the present invention will be described below with reference to the drawings. The control device can be widely applied to structures controlled by a plurality of control parameters, and is not limited to underwater vehicles as described below. For example, the control device can be applied to structures such as aircraft, rockets, and drones, regardless of whether it is manned or unmanned.

FIG. 1 is a diagram illustrating an underwater vehicle 1 equipped with a control device 20 according to one embodiment of the present invention. As shown in FIG. 1, an underwater vehicle 1 has a stern axis (hereinafter referred to as "x-axis"), a lateral axis (hereinafter referred to as "y-axis"), and a vertical axis (hereinafter referred to as "z-axis"). ) and three rotational axes for each of these linear axes (six degrees of freedom) are defined. Let u be the velocity in the x-axis direction, v be the velocity in the y-axis direction, and w be the velocity in the z-axis direction. Further, let the rotational angular velocity p about the x-axis be the roll angular velocity, the rotational angular velocity q about the y-axis be the pitch angular velocity, and the rotational angular velocity r about the z-axis be the azimuth angular velocity. Further, let the rotation angle φ about the x-axis in the absolute coordinate system (earth coordinate system) be the roll angle, the rotation angle θ about the y-axis be the pitch angle, and the rotation angle ψ about the z-axis be the azimuth angle. Note that the depth is the vertical direction (the z-axis direction in the absolute coordinate system) in the absolute coordinate system (the earth coordinate system). In the equations of motion of the airframe, the velocities in the six-axis directions in the airframe coordinate system are calculated, and coordinate transformation is performed to obtain the position and attitude in the absolute coordinate system.

A control device (control device with interference suppression function) 20 controls each control axis (depth, pitch angle, azimuth angle, roll angle) of the underwater vehicle 1 with the underwater vehicle 1 as a control target 30. conduct. Specifically, the control device 20 controls the depth actuator, the pitch angle actuator, the azimuth angle actuator, and the roll angle actuator, which are the target devices provided in the underwater vehicle 1, by controlling the operation amount (command value). The amount of control in each axial direction is controlled by giving Each actuator is a driving device that drives a movable part (for example, a rudder at the stern) provided on the hull to move the underwater vehicle 1 in each control axis direction. That is, the control device 20 performs control using each control axis (depth, pitch angle, azimuth angle, roll angle) as a control parameter. In this embodiment, the case where the depth and the pitch angle are used as control parameters will be described as an example, but other control parameters can be similarly applied.

The control device 20 includes, for example, a CPU (Central Processing Unit) (not shown), a memory such as a RAM (Random Access Memory), a computer-readable recording medium, and the like. A series of processes for realizing various functions described later is recorded in the form of a program on a recording medium, etc., and the CPU reads this program into RAM, etc., and executes processing and arithmetic processing of information. Various functions, which will be described later, are realized. The program may be pre-installed in a ROM or other storage medium, provided in a state stored in a computer-readable storage medium, or delivered via wired or wireless communication means. etc. may be applied. Computer-readable storage media include magnetic disks, magneto-optical disks, CD-ROMs, DVD-ROMs, semiconductor memories, and the like.

FIG. 2 is a functional block diagram showing functions of the control device 20. As shown in FIG. Note that the controlled object 30 shown in FIG. 2 is the underwater vehicle 1 and is not included in the control device 20 (it is controlled by the control device 20). As shown in FIG. 2, the control device 20 includes a depth feedback control section 21, a pitch angle feedback control section 22, an input conversion section 23, a linearization feedback section 24, and an interference suppression section 25. . Note that in FIG. 2 the strictly linearized system is shown as linearized system 28 . In addition, in the present embodiment, depth and pitch angle are used as control parameters as an example, so the depth feedback control section 21 and the pitch angle feedback control section 22 are provided in FIG. Applicable.

Based on the difference between the input target value of depth and the depth detected from the controlled object 30, the depth feedback control unit 21 provides a depth feedback control for a linearization system 28 (strictly linearized system), which will be described later. Calculate the input value. Specifically, the depth feedback control unit 21 receives the difference between the depth target value and the current depth detected from the controlled object 30 . Then, the depth feedback control unit 21 calculates and outputs a depth input value that reduces the difference. The input value output from the depth feedback control unit 21 is an input adapted to a linear system in which the controlled object 30 is strictly linearized, as will be described later. For example, a PID control method or the like can be appropriately applied to the feedback control unit.

The linearization system 28 is a linearized system (strict system linearized to ). That is, even if the controlled object 30 itself has non-linear characteristics, the overall linearization system 28 has linear characteristics.

Similar to the depth feedback control unit 21, the pitch angle feedback control unit 22 controls the linearization system 28 (strictly speaking, Calculate the pitch angle input for the linearized system).

The input conversion unit 23 performs input conversion in order to strictly linearize the nonlinear characteristics of the controlled object 30 on the input side of the controlled object 30 . In other words, the input conversion unit 23 performs input conversion between the input value input to the linearization system 28 to which strict linearization is applied and the command value input to the controlled object 30 of the linearization system 28. . Details of the input conversion unit 23 will be described later.

Note that the input conversion unit (conversion unit) 23 calculates a command value corresponding to each control parameter based on each input value of a plurality of control parameters, and outputs the command value to the controlled object 30 . That is, the command value of a certain control parameter output from the input converter 23 is calculated based on each input value of a plurality of control parameters. That is, each command value output from the input conversion unit 23 has coherency with each other. In other words, each command value output from the input unit is not calculated independently, but is related to each other, and the influence of one control parameter appears on another control parameter. In the present embodiment, strict linearization is described as an example when the command values of the control parameters interfere with each other. It is applicable not only to the input conversion unit 23 in the conversion method.

In order to strictly linearize the nonlinear characteristics of the controlled object 30, the linearization feedback unit 24 provides feedback to the input side of the controlled object 30 based on the detected control amount (for example, depth and pitch angle) of the controlled object 30. give feedback. In other words, the linearization feedback unit 24 complements the command value input to the controlled object 30 of the linearization system 28 by performing feedback based on the control amount of the controlled object 30 . Details of the linearization feedback unit 24 will be described later.

The interference suppression unit 25 performs correction for suppressing excessive control due to interference between control parameters. That is, the interference control unit suppresses unnecessary control (excessive control) caused by the interference when command values (command values input to the actuators) corresponding to each control parameter interfere with each other. As shown in FIG. 3, the underwater vehicle 1 automatically lowers its nose when the depth is lowered. For example, when the depth is lowered while the pitch angle is kept at 0°C (maintaining the current state), a command value for lowering the depth is output to the depth actuator, and fluctuations in the pitch angle accompanying depth descent are suppressed. A command value for the pitch angle actuator is output as follows. In this way, the depth command value and the pitch angle command value interfere with each other, and by driving each actuator based on these command values, the pitch angle is reduced to approximately 0°C (maintaining the current state). It is possible to lower the depth while

However, the actuator, which is the target device to which the command value is input, has operational limitations. The operation limit is, for example, the maximum rated value of the target device, and is a limit value indicating the operable limit such as angle saturation, stroke saturation, voltage saturation, and the like. Therefore, for example, when the depth is greatly lowered, the command value for the depth actuator becomes a large value and may exceed the limit value of the depth actuator to which it is input. In such a case, the depth actuator to which the command value is input cannot operate according to the command value, and operates within the limit value. That is, the actual depth actuator does not operate according to the depth command value. On the other hand, the command value for the pitch angle actuator, which is affected by the depth, is such that the change in pitch angle that accompanies the depth descent is suppressed. In other words, the command value for the pitch angle actuator is output so as to suppress variation when the depth actuator operates according to the command value. Assuming that the pitch angle will be significantly downward due to a large depth descent, the pitch angle command value is set so that an upward force is generated to cancel the large nose downward due to interference. . However, if the actual depth actuator does not operate according to the command value due to the limit value of the depth actuator, the upward force will increase based on the command value of the pitch angle, and there is a possibility that the nose will turn upward. there is (overregulation). This is because the command values of the control parameters that interfere with each other do not take into consideration the saturation of the command values (the limit values of the target equipment). Therefore, the interference suppression unit 25 corrects the input value so that the command value of the control parameter is output in consideration of the limit value of the target device.

For this reason, the interference suppressor 25 has a deviation calculator 27 and an input corrector 26 . In the present embodiment, the case where the depth actuator is provided with a limit value and the input value of the pitch angle is corrected will be described as an example, but the same can be applied to other control parameters. Since the interference suppressor 25 performs the correction outside the compensation loop of the linearization system 28, the correction can be performed independently of the linearization by the exact linearization method.

The deviation calculator 27 calculates the deviation between the command value and the threshold when the command value is equal to or greater than a predetermined threshold. Specifically, the command value of each control parameter is input to the deviation calculator 27, and it is determined whether or not each command value is equal to or greater than a threshold set for each control parameter. The threshold is set based on the maximum rated value of the target device (each actuator) of the controlled object 30 to which the command value is input. For example, in the case of depth, the command value for operating the depth actuator at the maximum rated value (limit value) is the threshold value (command saturation value). It should be noted that the threshold value may be a command value for operating with a value obtained by adding a predetermined margin to the maximum rated value of the target device. It is also assumed that thresholds are similarly set corresponding to the maximum rated values (maximum manipulated variables) for actuators that are other target devices. That is, when the command value is equal to or greater than the predetermined threshold, the command value requests driving equal to or greater than the maximum rated value of the actuator.

Then, when it is determined that the command value is equal to or greater than the threshold, the deviation calculator 27 calculates the deviation between the command value and the threshold. For example, if the threshold corresponding to the maximum rated value of the depth actuator is set at 100% and the depth command value indicates 120%, the deviation calculator 27 calculates 20% as the difference. .

When the command value is less than the predetermined threshold value, the deviation calculator 27 does not calculate the difference and outputs a predetermined reference value (initial value). For example, if the threshold value corresponding to the maximum rated value of the pitch angle actuator is set as 100% and the pitch angle command value indicates 50%, the deviation calculator 27 sets the initial value to 0%. Calculate

That is, the deviation calculation unit 27 compares the command value and the threshold value for each control parameter, calculates the difference between the command value and the threshold value for the control parameter whose command value is equal to or greater than the threshold value, and is less than the threshold value. For the command value control parameter, the initial value of the command value is calculated. Thus, the deviation calculator 27 calculates a value corresponding to each control parameter and outputs it to the input corrector 26 .

The input correction unit 26 corrects at least one of the input values corresponding to the control parameters other than the control parameter corresponding to the command value equal to or greater than the threshold using the correction value calculated using the deviation. Specifically, the input correction unit 26 subtracts the correction value from at least one of the input values corresponding to the control parameters other than the control parameter corresponding to the command value equal to or greater than the threshold.

The input correction unit 26 has the inverse characteristics of the input/output characteristics of the input conversion unit 23, and uses the inverse characteristics to calculate a correction value based on the deviation. The input conversion unit 23 calculates the command value of each control parameter based on the input value of each control parameter. In this embodiment, the input conversion unit 23 performs input/output conversion based on a strict linearization method, so the dimensions of the input value and the command value are different. Therefore, the input correction unit 26 corrects the dimension corresponding to the input value using the inverse characteristic of the input/output characteristic of the input conversion unit 23 based on the value corresponding to each control parameter output from the deviation calculation unit 27. Convert the value and output.

Then, the input correction unit 26 subtracts the calculated correction value from the input values corresponding to the control parameters other than the control parameter corresponding to the command value equal to or greater than the threshold. For example, when the depth command value is saturated, if the depth input value is corrected, the depth actuator will be operated at a capacity below the maximum capacity, which may reduce the responsiveness of the control in the direction of the depth axis. There is For example, when descending the depth, the depth descending speed becomes slow, and there is a possibility that the time until the depth reaches the target value will be delayed. Therefore, in the present embodiment, the input value corresponding to the control parameter having interference with the control parameter corresponding to the command value equal to or greater than the threshold value is corrected. Specifically, when the depth command value is equal to or greater than the threshold value, the pitch angle input value that interferes with the depth is corrected. Therefore, it is possible to suppress excessive control on the control axis that is subject to interference while suppressing deterioration in response performance on the control axis corresponding to the command value that is equal to or greater than the threshold.

For example, when 20% as a value related to depth and 0% as a value related to pitch angle are input to the input correction unit 26 from the deviation calculation unit 27, the input correction unit 26 outputs from the input conversion unit 23 Input values of depth and pitch angle are calculated as correction values so that the command value of depth is 20% and the command value of pitch angle is 0%. Then, the pitch angle input value is corrected using the pitch angle correction value. That is, the input value is corrected by subtracting the correction value of the pitch angle from the input value of the pitch angle, and the corrected input value is input to the input conversion unit 23 . In this way, when the pitch angle command value is excessive due to the saturation of the depth command value, since the correction value is subtracted from the pitch angle input value, the pitch angle command value becomes an excessive command.

Exact linearization techniques are now described.
A strict linearization method is a method of performing linearization in the entire characteristic range without approximation using a nonlinear model that indicates the nonlinear characteristics of the controlled object. That is, linearization is performed between the input and output of the controlled object.

Assuming that the command value to the controlled object is the input Δ and the control amount detected from the controlled object is the output Y, the input Δ and the output Y in the underwater vehicle 1 are as follows.

In equation (1), δ1 is the command value (operation command) for the depth actuator, δ2 is the command value (operation command) for the pitch angle actuator, and δ3 is the command value (operation command) for the azimuth actuator. command), and δ4 is a command value (operation command) for the roll angle actuator. In equation (2), z is the depth control amount, θ is the pitch angle control amount, ψ is the azimuth angle control amount, and φ is the roll angle control amount. That is, when a command value is given to an object to be controlled, each actuator is driven, and the current value in each control axis direction is output by a sensor or the like as a control amount.

When time differentiation is performed on the control amount, which is the output in equation (2), the input of equation (1) appears, for example, at the time of the second order differentiation, and the nonlinear equation of motion at this time is as follows.

In equation (3), u, v, and w are the velocity in the stern axis direction, the velocity in the lateral axis direction, and the velocity in the vertical axis direction, respectively, in the hull coordinate system. Also, p, q, and r are the angular velocity around the stern axis, the angular velocity around the lateral axis, and the angular velocity around the vertical axis, respectively, in the hull coordinate system. fz, fθ, fψ, and fφ are a function related to depth, a function related to pitch angle, a function related to azimuth angle, and a function related to roll angle, respectively. In addition, gz1 to gz4 are functions related to depth, gθ1 to gθ4 are functions related to pitch angles, gψ1 to gψ4 are functions related to azimuth angles, gφ1 to gψ4 are functions related to roll angles, and the matrix is each element of

In general, the output of a controlled object having nonlinear characteristics appears as the input as shown in Equation (3) by first-order or multiple-order differentiation. That is, the first-order or multi-order differentiation of the output and the linear expression of the input can be represented by an equation. Equation (3) shows an example of second-order differentiation, but the order of differentiation varies depending on the controlled object, and other than first-order differentiation and second-order differentiation are similarly applicable.

Here, let ν be the second derivative of the output, which is the left side of equation (3), let F be the constant term (the term that does not apply to the input Δ), and let G be the term that applies to the input Δ. are arranged as follows.

(4) becomes the following formula by transforming it with respect to the input Δ.

From the relationship of equation (5), ν is the new input, F is the feedback conversion, and 1/G is the input conversion. can be converted into an input-output relationship (input ν-output Y). Note that the feedback conversion of F corresponds to the linearization feedback section 24 in FIG. 2, and the input conversion of 1/G corresponds to the input conversion section 23 in FIG. The relationship between input ν and output Y for the exact linearized system of FIG.

When the relationship of the equation (6) is shown by a transfer function, the input/output relationship is as shown in FIG. That is, the nonlinear characteristics of the controlled object can be converted into a diagonal matrix having quadratic integral elements as diagonal components by applying a strict linearization technique. Note that the order of the integral elements of the diagonal matrix changes in accordance with the order of differentiation of the output Y. In this way, by adding feedback transformation and input transformation to the controlled object to form a linearization system, it is possible to linearize strictly between input and output.

That is, in an equation between the first-order or multiple-order differentiation of the output (controlled variable) of the controlled object 30 having nonlinear characteristics and the linear expression of the input (command value), the constant term of the input linear expression is used as the input conversion, If the coefficients of the first-order terms are feedback transforms, the characteristic between the new input (differentiated output) and the output is exactly linearized.

In this way, rigorous linearization refers to the command value is to add an input conversion unit 23 and a linearization feedback unit 24 so as to be able to calculate . Since the controlled object 30 to which the input conversion unit 23 and the linearization feedback unit 24 are added has a relationship where the input is the one or more orders of differentiation of the output when viewed as the whole linearization system 28. , the linearization system 28 as a whole is linearized.

The configuration of the linearization feedback unit 24 and the configuration of the input conversion unit 23 are not limited to those described above and can be applied. For example, in the above example, F is the feedback transform and 1/G is the input transform, but by modifying the equation (5), as shown in FIG. may be used as the input conversion. Also, in the above example, strict linearization between input and output was described, but state linearization is similarly applicable.

Next, the effect of the control device 20 described above will be described with reference to FIGS. 7-10. Note that in FIGS. 7-10, the characteristics when the target depth value is changed at time T0 will be described as an example. 7 to 10, reference example 1 is the case where each control parameter is controlled independently without using strict linearization control or the like (for example, FIG. 11). That is, the reference example 1 is an example in which the depth command value and the pitch angle command value are determined independently of each other. 7 to 10, reference example 2 is the case where strict linearization control is applied to the controlled object and the interference suppression unit 25 is not used (for example, FIG. 12). That is, Reference Example 2 is an example in which strict linearization is simply applied to the controlled object 30 without correcting the input by the interference suppression unit 25 .

FIG. 7 is a diagram showing changes in depth over time when the target depth value is changed. FIG. 8 is a diagram showing changes over time of the depth actuator when the target depth value is changed. FIG. 9 is a diagram showing changes over time in the pitch angle when the target depth value is changed. FIG. 10 is a diagram showing the change over time of the pitch angle actuator when the target depth value is changed. 7-10, the characteristics of Reference Example 1 are indicated by a dotted line L1, the characteristics of Reference Example 2 are indicated by a dashed-dotted line L2, and the characteristics of the present embodiment are indicated by a line L3 (continuous line). there is

In Reference Example 1 (dotted line L1), as shown in FIG. 7, when the target depth value is changed at time T0, a command value for the depth actuator is output to match the depth with the target value (see FIG. 8 ). It is assumed that the command value is equal to or greater than the threshold. The depth actuator to which the command value is input operates at the maximum capacity of the limit value (-100%). On the other hand, as shown in FIG. 9, the pitch angle fluctuates as the depth changes, so the pitch angle actuator is driven so as to suppress the fluctuation. In Reference Example 1, the control system is designed independently for each control parameter, and the command values for each control parameter are independent of each other. Therefore, the depth command value is determined based on the current depth, and the pitch angle command value is determined based on the current pitch angle. That is, in Reference Example 1, the command value of the pitch angle is determined without depending on the saturation of the command value of the depth, so as shown in FIG. 7, the responsiveness to the target value of the depth is good. However, in Reference Example 1, the control system is designed independently for each control parameter, and the controlled object 30 is not strictly linearized, so the control accuracy is low. FIG. 13 shows an enlarged view along the vertical axis of the time change of the pitch angle in FIG. FIG. 14 is an enlarged view of the change over time of the pitch angle actuator in FIG. 10 along the vertical axis. As shown in FIGS. 13 and 14, each actuator may finely fluctuate, leading to an increase in power consumption.

In Reference Example 2 (one-dot chain line L2), as shown in FIG. 7, when the target depth value is changed at time T0, a command value for the depth actuator is output to match the depth with the target value (see FIG. 7). 8). It is assumed that the command value is equal to or greater than the threshold. The depth actuator to which the command value is input operates at the maximum capacity of the limit value (-100%). On the other hand, as shown in FIG. 10, in Reference Example 2, the pitch angle command value is calculated assuming that the depth actuator is driven based on a command value larger than the threshold value. is largely driven, and the pitch angle fluctuates greatly as shown in FIG. In Reference Example 2, the nonlinear characteristics of the controlled object 30 are linearized by a strict linearization method, and the command values of the respective control parameters interfere with each other. However, in the strict linearization method, although the controlled object 30 can be linearized with high accuracy and the control accuracy can be improved, the saturation of the command value of each control parameter cannot be considered. As a result, the pitch angle is controlled to a large extent (excessive control), and the force acts in the direction in which the nose is turned upward and the depth increases. time) will decrease.

Therefore, in the present embodiment (line L3), the controlled object 30 is linearized by a strict linearization method, and the input value of each control parameter is corrected in consideration of the saturation of the command value (interference suppression unit 25). Therefore, in the present embodiment, when the target depth value is changed at time T0, a command value is output to the depth actuator to match the depth with the target value (FIG. 8). It is assumed that the command value is equal to or greater than the threshold. The depth actuator to which the command value is input operates with the maximum capacity of the limit value (-100%). On the other hand, as shown in FIG. 10, in the present embodiment, the saturation of the depth command value is taken into consideration when calculating the pitch angle command value. As shown, variations in pitch angle are suppressed. In this embodiment, since excessive control is suppressed in consideration of saturation of the command value, responsiveness is high as shown in FIG. In addition, since a strict linearization method is applied and each control parameter is controlled in relation to each other (each control parameter is not independently controlled), each actuator This suppresses fine fluctuations in the power consumption, thereby suppressing an increase in power consumption. That is, in the present embodiment, it is possible to suppress interference between control parameters and achieve stable control and low power consumption without impairing responsiveness.

As described above, according to the control device 20, its control method, control program, and structure according to the present embodiment, even if the command values corresponding to the respective control parameters interfere with each other, the command value and the In order to correct the input value for calculating the command value based on the deviation from the threshold, for example, considering the saturation (limit value) of the drive amount of the actuator etc. to which the command value is input, between each control parameter Interference can be suppressed.

For example, if the control parameters are depth and pitch angle, and the depth command value is greater than or equal to a predetermined threshold value, the depth command value may exceed the limit value of the target device such as the input actuator. . In such a case, the target device cannot be driven above the limit value, and the depth command value is not fully reflected. However, since the pitch angle command value that interferes with the depth command value cannot consider the limit value of the target device, the command value is calculated assuming that the target device is driven by the depth command value. Therefore, there is a possibility that the pitch angle command value will be inappropriate (excessive control).

Therefore, when the command value is equal to or greater than a predetermined threshold value, the input value corresponding to the control parameter other than the control parameter corresponding to the command value equal to or greater than the threshold value is corrected based on the deviation between the command value and the threshold value. did. Therefore, for example, it is possible to modify the command value of each control parameter in consideration of the threshold value of the command value, such as the limit value of the target device.

In addition, since the input value corresponding to the control parameter other than the control parameter corresponding to the command value that is equal to or higher than the threshold is corrected, the control parameter corresponding to the command value that is equal to or higher than the threshold is controlled at the maximum capacity while preventing interference. Command values of other received control parameters can be corrected.

That is, even if there is interference between the command values of the control parameters, it is possible to suppress excessive control due to interference without deteriorating responsiveness, thereby improving stability and suppressing power consumption.

The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the invention.

For example, the control object is an underwater vehicle, and the control parameters are depth, pitch angle, azimuth angle, and roll angle. , the control parameters are appropriately set by the applied structure.

1: underwater vehicle 20: control device 21: depth feedback control unit 22: pitch angle feedback control unit 23: input conversion unit 24: linearization feedback unit 25: interference suppression unit 26: input correction unit 27: deviation calculation unit 28 : Linearization system 30 : Control object

Claims (8)

a conversion unit that calculates a plurality of command values corresponding to each of the plurality of control parameters based on a plurality of input values corresponding to each of the plurality of control parameters, and outputs the command values to a controlled object;
a deviation calculation unit that calculates a deviation between the predetermined command value and the threshold when a predetermined command value among the plurality of command values is equal to or greater than a predetermined threshold;
At least one of the input values corresponding to the other control parameters having interference with the control parameter corresponding to the predetermined command value that is equal to or greater than the threshold is a correction value calculated using the deviation. an input correction unit that corrects using
A control device comprising: A linearization feedback unit for strictly linearizing the nonlinear characteristics of the controlled object,
2. The control device according to claim 1, wherein the conversion unit performs input value conversion for strict linearization of the nonlinear characteristics on the input side of the controlled object. 3. The input correction unit subtracts the correction value from at least one of the input values corresponding to the control parameters other than the control parameter corresponding to the command value equal to or greater than the threshold. The control device according to . 4. The input correction unit according to any one of claims 1 to 3, wherein the input correction unit has an inverse characteristic of the input/output characteristic of the conversion unit, and calculates the correction value based on the deviation using the inverse characteristic. controller. The control device according to any one of claims 1 to 4 , wherein the threshold value is set based on a maximum rated value of the target device to be controlled to which the command value is input. A structure comprising a control device according to any one of claims 1 to 5 . a conversion step of calculating a plurality of command values corresponding to each of the plurality of control parameters based on a plurality of input values corresponding to each of the plurality of control parameters and outputting them to a controlled object;
a deviation calculation step of calculating a deviation between the predetermined command value and the threshold when a predetermined command value among the plurality of command values is equal to or greater than a predetermined threshold;
At least one of the input values corresponding to the other control parameters having interference with the control parameter corresponding to the predetermined command value that is equal to or greater than the threshold is a correction value calculated using the deviation. an input correction step of correcting using
Control method including. a conversion process of calculating a plurality of command values corresponding to each of the plurality of control parameters based on a plurality of input values corresponding to each of the plurality of control parameters and outputting them to a controlled object;
a deviation calculation process for calculating a deviation between the predetermined command value and the threshold when a predetermined command value among the plurality of command values is equal to or greater than a predetermined threshold;
At least one of the input values corresponding to the other control parameters having interference with the control parameter corresponding to the predetermined command value that is equal to or greater than the threshold is a correction value calculated using the deviation. Input correction processing to correct using
A control program that causes a computer to execute

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