KR20210115498A - Control device and control method - Google Patents

Abstract

A control device is provided. The control device may include: a transformation part for transforming a first coordinate system used for controlling an object moving along a target trajectory into a second coordinate system based on the target trajectory; and an analysis part for analyzing error dynamics for the object following the target trajectory based on the second coordinate system.

Description

CONTROL DEVICE AND CONTROL METHOD

The present invention relates to a control apparatus and a control method for controlling an object moving along a target trajectory.

Autonomous unmanned submersibles often have a toffee shape to reduce fluid resistance. The autonomous unmanned vehicle moves using the thruster at the rear of the submersible and the rudder and elevator for direction adjustment. The autonomous unmanned vehicle cannot independently perform lateral movement and rotational movement, and has a non-holonomic constraint.

The autonomous unmanned vehicle performs its mission autonomously while moving along a pre-programmed route/trajectory.

In order to accurately perform a given mission, it is necessary to precisely follow a designated route. However, in the aquatic environment, there are disturbances by the environment such as currents and waves, and these disturbances interfere with tracking of the set path/trajectory. In addition, in order to accurately follow the trajectory, it is necessary to accurately estimate and compensate the dynamics of the autonomous unmanned vehicle, which also comes with many difficulties. This is because the autonomous unmanned submersible (UAV) operated in the water is very non-linear and has strongly coupled dynamics because rigid body dynamics and fluid dynamics are combined. Therefore, considerable effort is required to establish a dynamic model of the autonomous unmanned vehicle and estimate the coefficients of the model, and it is inevitably accompanied by a dynamic model estimation error. The model estimation error is a factor that degrades the trajectory tracking performance.

Korean Patent Publication No. 1370649 discloses a path control technology that calculates real-time speed information and a direction difference between a set path to estimate the influence of the current, and cancel the influence of the current in real time.

Korean Patent Publication No. 1370649

An object of the present invention is to provide an apparatus and method for controlling an object to precisely move along a target trajectory.

A control apparatus of the present invention includes: a transformation unit for converting a first coordinate system used for controlling an object moving along a target trajectory into a second coordinate system based on the target trajectory; and an analysis unit that analyzes error dynamics for the object following the target trajectory based on the second coordinate system.

The control method of the present invention includes an analysis step of analyzing the dynamics of a submersible having a non-holonomic constraint by introducing a coordinate transformation; A correction step of correcting disturbance caused by the coordinate transformation; including, wherein the coordinate transformation transforms the existing coordinate system used for control of the submersible moving along the target trajectory into a reference trajectory coordinate system based on the target trajectory. In this case, a backstepping control technique may be applied through the coordinate transformation, and the correction of the disturbance may include a process of suppressing the occurrence of the disturbance by applying the backstepping control technique.

The control apparatus and control method of the present invention can provide a controller that is structurally simple and robust against disturbance and dynamic nonlinearity.

The present invention can easily analyze the dynamics of an object by introducing a coordinate transformation, for example, the dynamics of an autonomous unmanned vehicle having non-holonomic constraints.

The dynamics analyzed using the coordinate transformation can have a form to which the backstepping control technique can be easily applied. Therefore, according to the present invention, a back-stepping control technique that has been difficult to be applied to a submersible may be introduced. As a result, it is possible to provide a controller robust against disturbance that does not satisfy a matching condition based on a back-stepping control technique.

According to the present invention, dynamics of an object of an autonomous unmanned vehicle can be indirectly and robustly estimated using time delay estimation.

According to the present invention, a robustness controller that enables precise trajectory tracking of an autonomous unmanned submersible, including the difficulty of precise control, can be provided.

1 is a block diagram showing a control device of the present invention.
2 is a schematic diagram showing the LOS-based bow angle path plan of the comparative example.
3 is a schematic diagram illustrating a state variable and a coordinate system of an object.
4 is a graph showing the simulation results of the autonomous unmanned submersible controlled by the control device of the present invention.
5 is a graph showing the change of the bow angle with respect to the result of the initial error.
6 is a flowchart illustrating a control method of the present invention.
7 is a schematic diagram showing a control flowchart according to the control method of the present invention.
8 is a diagram illustrating a computing device according to an embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those of ordinary skill in the art to which the present invention pertains can easily implement them. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein. And in order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are attached to similar parts throughout the specification.

In the present specification, duplicate descriptions of the same components will be omitted.

Also, in this specification, when it is mentioned that a certain element is 'connected' or 'connected' to another element, it may be directly connected or connected to the other element, but another element in the middle. It should be understood that there may be On the other hand, in this specification, when it is mentioned that a certain element is 'directly connected' or 'directly connected' to another element, it should be understood that the other element does not exist in the middle.

In addition, the terms used herein are used only to describe specific embodiments, and are not intended to limit the present invention.

Also, in this specification, the singular expression may include the plural expression unless the context clearly dictates otherwise.

Also in this specification, terms such as 'include' or 'have' are only intended to designate that the features, numbers, steps, operations, components, parts, or combinations thereof described in the specification exist, and one or more It should be understood that the existence or addition of other features, numbers, steps, operations, components, parts or combinations thereof is not precluded in advance.

Also in this specification, the term 'and/or' includes a combination of a plurality of listed items or any of a plurality of listed items. In this specification, 'A or B' may include 'A', 'B', or 'both A and B'.

Also, in this specification, detailed descriptions of well-known functions and configurations that may obscure the gist of the present invention will be omitted.

1 is a block diagram showing a control device of the present invention. 3 is a schematic diagram illustrating a state variable and a coordinate system of an object.

Path planning based on line of sight (LOS) and proportional-derivative (PD) control techniques are mainly used for trajectory tracking control of autonomous unmanned vehicles. The LOS is shown in FIG. 2 as an algorithm for deriving a bow angle for following a straight line connecting between path points when path points are given in advance. LOS is a technique that is widely used because of the simplicity of the algorithm, but there are structural limitations.

For example, when LOS is applied, there is a problem in that it is difficult to apply to tracking other than a straight trajectory. In the case of applying LOS, it is necessary to set the radius of the circle of acceptance in advance, and there is a problem that separate processing is required for the case where there is no intersection of the circle and the straight trajectory. In addition, there is a problem that separate processing is required for the case where the route point exists inside the receiving circle. In addition, it is necessary to determine whether the submersible has reached the path point and to update the straight trajectory to the next path point when the sub vehicle arrives at the path point. In addition, when the route point of the submersible is changed, there is a problem that the bow angle route plan value is discontinuously changed.

In addition, the PD-type controller leaves a steady state error with respect to disturbance due to the characteristics of the controller that does not include an integral term, and thus there is a limit in performing precise trajectory tracking. In particular, in the case of large disturbances such as birds, the trajectory tracking error increases, making it difficult to perform precise tasks.

Algorithms for precise trajectory tracking of autonomous unmanned vehicles have been continuously studied for the past several decades. Many of these studies use the backstepping control technique to solve the matching condition problem. However, there is a limitation that the dynamic model of the autonomous unmanned vehicle needs to be known, and there is a problem of mathematical complexity as it is developed based on the derivative of the nonlinear objective function. Also, there are approaches based on the hierarchical design of the controller, for example, feedback design of reference speed and terminal sliding mode control, backstepping control and sliding mode control, guidance design and fuzzy control, etc. By introducing a kinematic level controller, they separate the matching condition problem from the dynamic control problem. However, there is a problem that the convergence of the kinematic controller has a mutual influence with the convergence of the dynamic controller, and there is also a disadvantage that a dynamics model of the autonomous unmanned vehicle is required.

In order to provide a controller that is structurally simple and robust against disturbance and dynamic nonlinearity, the control device shown in FIG. 1 may include a converter 110 and an analyzer 130 .

The transformation unit 110 may convert the first coordinate system used to control the object 10 moving along the target trajectory c into a second coordinate system based on the target trajectory. The object 10 may include various objects moving in a fluid such as water or air. As an example, the object may include an airplane traveling in air, a vessel sailing on water, a submersible moving in water, and the like.

The first coordinate system may include any one of an earth coordinate system, a body fixed coordinate system based on an object, and a relative coordinate system based on a third object that is distinguished from the object.

The earth coordinate system may include a rectangular right coordinate system in which an x-axis and a z-axis indicate a true north direction and a direction toward the center of the earth, respectively. Instead of the x-axis in the Earth coordinate system, the y-axis may represent the true north direction.

The body fixed coordinate system may include a right-angled right coordinate system in which the x-axis or y-axis is parallel to the longitudinal direction of the object, and the vertical downward/upper side of the object is the z-axis. The center of the body fixed coordinate system may be located at the center of buoyancy.

The relative coordinate system may include a right-angled coordinate system in which the x-axis or the y-axis is parallel to the longitudinal direction of the third object, and the vertical downward/upper side of the third object is the z-axis.

The transform unit 110 may convert the first coordinate system into a second coordinate system having a first axis in contact with the target trajectory c and a second axis perpendicular to the target trajectory. The origin of the second coordinate system may be located at the foot (intersection of the corresponding perpendicular and the target trajectory c) of the waterline descending from the origin of the body fixed coordinate system to the target trajectory c.

The first axis of the second coordinate system may represent a forward distance error or forward speed error of the object.

The second axis of the second coordinate system may represent a lateral distance error, a heading angle (bow angle) error, or an angular velocity error of the object.

In FIG. 3 , only the motion on the xy plane is considered for the sake of simplicity of expression. The definitions of the coordinate system and state variables used in the present invention are shown in FIG. 3 . In FIG. 3 , the object may include an autonomous unmanned vehicle operating in water.

{W} may represent the earth coordinate system, and {B} may represent a body fixed coordinate system. The reference trajectory coordinate system {D} may correspond to the second coordinate system.

Position and bow state variables (x, y, ψ) with respect to the Earth coordinate system can be defined. Velocity and rotational velocity variables (u,v,r) for the body fixed coordinate system can be defined.

The target trajectory (reference trajectory) c assumes that (x,y) location information is independently defined, and the target trajectory expressed by Equation 1 may be derived dependently.

Here, ψ _d represents the bow angle and u _d represents the forward speed. r _d represents the angular velocity.

The behavior of the submersible in the plane can be controlled using thrusters and rudder. That is, the speed may be controlled using the _{thrust τ u of the thruster.} The bow angle can be controlled using the rudder input τ _{r .}

The dynamics of the object can be expressed as Equation (2).

,

은 대상물의 이너셔항에 기반하여 선정되는 양의 상수이다.here,

,

is a positive constant selected based on the inertia term of the object.

h _u and h _r represent the non-linear dynamics of the object.

The kinematics of the object can be expressed as Equation (3).

이고,

이다. '

'은 임의의 문자를 나타낸다.here,

ego,

am. '

' represents any character.

In Equation 3, three variables (x, y, ψ) may be determined by two independent variables (u, r). Therefore, it can be seen that the object such as a submersible is an underactuated system.

와 같이 유도되는 비홀로노믹 제약이 존재하는 것을 알 수 있다.It can be seen that the transverse velocity v is not separately controlled and acts as a disturbance. Also, ignoring the lateral velocity v,

It can be seen that there is a non-holonomic constraint induced as

In Equation 3, it can be seen that the relationship between the independent variable (u) and the dependent variable (x,y) changes according to the bow angle (ψ). For example, when the bow angle is 0 degrees, u determines the change in x, whereas when the bow angle is 90 degrees, u determines the change in y. Coordinate transformations can be introduced to reduce changes in the relationship between the independent and dependent variables.

For example, if the problem defined in the earth coordinate system {W} corresponding to the first coordinate system is transformed into the reference locus coordinate system {D} corresponding to the second coordinate system, the problem of relationship change may be alleviated.

The transform unit 110 may perform coordinate transformation using a homogeneous transform matrix. As an example, the transformation matrix may be as in Equation (4).

The dynamics of Equation 3 and the error dynamics for the object having the kinematics of Equation 4 following the target trajectory of Equation 1 may be expressed as Equations 5, 6, and 7 below. If the corresponding error dynamics are analyzed or expressed for the reference trajectory coordinate system {D} using the coordinate transformation of Equation 4, Equation 5, Equation 6, and Equation 7 are obtained.

이고, '

'은 임의의 문자를 나타낸다.

,

는 양의 상수이다. here,

ego, '

' represents any character.

,

is a positive constant.

, 전진 속도 오차

, 횡방향 오차(제2 축상 거리 오차)

, 헤딩각 오차

, 각속도 오차

중 적어도 하나가 포함될 수 있다.In the error dynamics analyzed based on the second coordinate system by the analysis unit 130, the forward distance error (the first on-axis distance error)

, forward speed error

, lateral error (second axial distance error)

, heading angle error

, angular velocity error

At least one of them may be included.

According to Equations 5 and 6, the error dynamics of the object may include _{disturbances (λ x} ,λ _{y ) that do not satisfy the matching condition.} In addition, according to Equation 7, it can be seen that the disturbance that does not satisfy the matching condition is generated by the lateral velocity v caused by the current or the like along with various error terms.

The matching condition indicates that the object moves according to the first value (following) when the first value is input, and dissatisfaction of the matching condition indicates a state in which the object cannot move according to the first value despite the input of the first value. can For example, an error that cannot be adjusted using a driving force and a rudder angle that physically affects the motion of an object, that is, an error about a part that cannot be applied with force, may correspond to disturbance. Since the disturbance cannot be resolved by using the thruster that generates the thrust and the rudder that controls the direction, it is better to suppress it so that it does not occur as much as possible.

When there is a disturbance that does not satisfy the matching condition, the analyzer 130 may design or generate a controller using a backstepping control technique. For example, the analysis unit 130 may generate the error dynamics in a form to which the backstepping control technique can be applied using the second coordinate system. Equation 5 or 6 may satisfy a so-called strict-feedback form. The backstepping controller design for the corresponding form can be applied as it is with existing technology based on Liapunov stability. The backstepping control technique may be a robust controller design technique against disturbances that do not satisfy the matching condition. The analysis unit 130 may apply the backstepping control technique to the error dynamics of the object so that the disturbance is suppressed. The analysis unit 130 may be provided with a design means for designing or generating a controller to which the backstepping control technique is applied.

The analyzer 130 may generate a backstepping controller of an object that follows a target trajectory by applying a backstepping control technique to error dynamics. As an example, the backstepping controller for Equations 5 and 6 may be designed as in Equations 8, 9, 10 and 11.

는

의 추정값이고,

은 제어 게인이다.here,

Is

is an estimate of

is the control gain.

The Liapunov function may be set as in Equation 12 by the analysis unit 130 .

), Liapunov function의 미분값은 수학식13과 같이 negative definite를 만족하여 안전성이 보장될 수 있다.For the Liapunov function of Equation 12, substituting the controller of Equation 8 and assuming that there is no estimation error (

), the differential value of the Liapunov function satisfies negative definite as in Equation 13, so safety can be guaranteed.

,

은 대상물의 비선형 동역학의 추정값이고,

,

는 매칭 조건을 만족하지 않는 외란의 추정값이다.The backstepping controller may include at least one of an estimated value of nonlinear dynamics of an object and an estimated value of disturbance that does not satisfy a matching condition. Equation 8, Equation 9, Equation 10, Equation 11

,

is an estimate of the nonlinear dynamics of the object,

,

is an estimate of the disturbance that does not satisfy the matching condition.

The analyzer 130 may estimate, calculate, or analyze at least one of an estimate value of nonlinear dynamics and an estimate value of disturbance by using a time delay estimation technique using a previous sampling time value. The analysis unit 130 may be provided with an estimating means for estimating or calculating the disturbance by using the time delay estimation technique.

Each estimate requires a lot of effort to directly derive the model and estimate the coefficients. The analysis unit 130 of the present invention can estimate the estimated value concisely and robustly by using the time delay estimation technique. Time delay estimation is an indirect estimation method that does not directly use a model, and it is structurally very simple because it utilizes the previous sampling time values of the input and output of the system. For the time delay estimation, it is based on the assumption that the change in the dynamics of the system that occurs in a very short time is very small and therefore negligible. That is, from the first expression of Equation 2, Equation 5, Equation 6, the dynamics can be estimated as Equations 14 and 15 using the system input/output values before a short time (L, using a normal sampling time). can For example, the previous sampling time value may include a sampling time value prior to one sampling period with respect to the current sampling period.

Using the time delay estimation technique, it is very simple to obtain an estimate of the dynamics. Finally, the analysis unit 130 may generate a controller represented by at least one of Equation 8, Equation 9, Equation 10, Equation 11, Equation 14, and Equation 15.

The controller may be used to control an object that precisely follows a target trajectory while being robust to disturbances in an environment in which severe disturbances exist, for example, in an underwater environment in which algae exist.

The analysis unit 130 may suggest stability analysis of the controller. In addition, the analysis unit 130 may select a gain of the controller based on the analysis of the stability seat.

Conditions for the controller generated by the analysis unit 130 to be stable are the same as Equations 16, 17, and 18.

In Equation 16, A _x , A _y is a Hurwiz matrix. If Equation 17 is satisfied, the controller generated by the analysis unit 130 is stable. The design method of the control gain can be calculated|required from the above stability conditions.

The control gain design method is as follows.

First, in the case of the feedback control gain (K), _{from the condition that A x} , A _y of Equation 16 must be Hurwiz, the poles of Equation 19 are all designed to exist in the Left Half Plane (LHP). Do it.

등의 이너셔 게인(inertial gain)의 경우, 수학식17로부터 설계 방법을 구할 수 있다. 수학식17을 풀어 쓰면 수학식19와 같은 조건이 유도될 수 있다.

In the case of an inertial gain such as, a design method can be obtained from Equation 17. By solving Equation 17, the same condition as Equation 19 can be derived.

From Equation 19, it can be confirmed the condition of each inertia gain for the controller to be stable.

Some conditions are based on the dynamic coefficient of an object, such as an autonomous unmanned vehicle moving in water, and if the actual value is difficult to know, it can be selected through tuning.

이내이어야 한다는 것이다. 이 조건은 물리적으로 타당할 수 있다. 잠수정의 선수각은 방향타를 이용하여 제어되는데, 잠수정이 후진할 경우에는 방향타에 의한 힘의 방향이 반대가 된다. 마찬가지로, 선수각 오차가

이상이 되면, 방향타의 변환에 따른 선수각 변화 방향이 반대가 된다. 해당 조건을 만족하기 위해, 분석부(130)는 대상물이 전진해야 하는 조건 및 선수각 오차가 90도 이내(대상물의 전진 방향을 기준으로 ±90°이내)를 만족하는 범위 내에서 백스테핑 제어기의 게인을 선정할 수 있다.Equation 19 may include other conditions (parts expressed as 'others') in addition to the inertia gain. If the conditions are specified, the object must advance, and the bow angle error is

it should be within This condition may be physically justified. The submersible's bow angle is controlled by using the rudder, and when the submersible is moving backwards, the direction of the force by the rudder is reversed. Similarly, the bow angle error

If the abnormality occurs, the direction of the change of the bow angle according to the change of the rudder is reversed. In order to satisfy the corresponding condition, the analysis unit 130 controls the backstepping controller within a range that satisfies the condition that the object must advance and the bow angle error is within 90 degrees (within ±90 degrees based on the forward direction of the object). You can select the gain.

The control device of the present invention can be used for trajectory tracking control of an autonomous unmanned vehicle that is operated or operated in water. Track tracking control is a very fundamentally required technology in the operation of autonomous unmanned submersibles. The trajectory tracking control can be used in general operations such as launching and moving the submersible to the target area, performing the mission in the target area, and moving to the recovery point after performing the mission.

A simulation was conducted using the REMUS 100, which is a representative model of an autonomous unmanned vehicle. The kinetic model of REMUS 100 is presented in 'Prestero, 2001, Ph.D Thesis MIT'. Using the kinetic model of REMUS 100, a simulation was performed on the XY plane behavior, and the results are shown in FIG. 4 .

4 is a graph showing the simulation results of the autonomous unmanned submersible controlled by the control device of the present invention.

Figure 4 shows the simulation results for three initial conditions on the XY plane.

The reference trajectory (target trajectory) was moved 50 m in a straight line, and then a trajectory drawing a circle with a radius of 10 m was applied. According to the controller designed or generated by the analysis unit 130 of the present invention for the initial error including the angle error of 60 degrees and the y-direction error within 10 m, the autonomous unmanned vehicle stably converges to the reference trajectory and follows the trajectory. has been confirmed to perform.

5 is a graph showing the change of the bow angle with respect to the result of the initial error.

In FIG. 5, changes in X, Y, and bow angles with respect to the results of the initial error (bow angle 60 degrees, y direction 0 m) are shown with respect to time. According to the control device of the present invention, it was confirmed that the initial error of the object was overcome and the object accurately followed the reference trajectory.

6 is a flowchart illustrating a control method of the present invention.

The control method of the present invention may be performed by the control device shown in FIG. 1 .

The control method of the present invention may include a transformation step (S510), an analysis step (S520), a correction step (S530), and an estimation step (S540). The conversion step ( S510 ) may be performed by the conversion unit 110 . The analysis step (S520), the correction step (S530), and the estimation step (S540) may be performed by the analysis unit 130 .

Coordinate transformation may be performed through the transformation step ( S510 ). Through the transformation step S510 , the existing first coordinate system used for controlling an object moving along the target trajectory may be converted into a second coordinate system based on the target trajectory. In other words, the coordinate transformation may include converting the existing coordinate system used for controlling the submersible moving along the target trajectory into a reference trajectory coordinate system based on the target trajectory.

Through the analysis step (S520), the analysis unit 130 can introduce the coordinate transformation and analyze the dynamics of the submersible having a non-holonomic constraint. The application of the backstepping control technique may be possible through coordinate transformation. This is because, in order to apply the backstepping control technique, it is necessary to understand the dynamics of the submersible, because the dynamics of the submersible can be easily grasped through the introduction of coordinate transformation.

Through the correction step (S530), the analysis unit 130 may correct the disturbance included in the dynamics model of the submersible. The correction of disturbance may include a process of designing or generating a backstepping controller that suppresses the occurrence of disturbance by applying a backstepping control technique. A correction step can create a backstepping controller for a submersible with disturbance suppressed.

Through the estimation step (S540), the analysis unit 130 may estimate at least one of the estimated value of the disturbance and the estimated value of the nonlinear dynamics of the submersible included in the backstepping controller.

In the estimating step ( S540 ), at least one of an estimate value of nonlinear dynamics and an estimate value of disturbance may be estimated using a time delay estimation technique.

According to the above-described control device and control method, precise trajectory tracking control of an autonomous unmanned submersible with non-holonomic constraints is possible in the presence of disturbances such as birds. Through this, the degree of completion of the exploration results can be improved in missions such as underwater terrain exploration using an autonomous unmanned vehicle.

7 is a schematic diagram showing a control flowchart according to the control method of the present invention.

The design means of the analysis unit 130 may analyze the error dynamics (a) for the target 10 following the target trajectory based on the second coordinate system. The analysis result can be expressed by Equation 5 ⑤ and Equation 6 ⑥.

The backstepping control technique (c) may be applied to each factor included in Equation 5 ⑤ and Equation 6 6 representing the error dynamics by design means.

The design means may calculate the virtual input (c-1) for dynamic compensation that does not satisfy the matching condition as in Equations 10 ⑩ and Equations 11 ⑪.

The design means may substitute the calculated virtual input (c-1) to the reference input (c-2) including dynamic compensation that does not satisfy the matching condition. The corresponding reference input (c-2) may be expressed by Equation 9 ⑨.

The design means may substitute the reference input (c-2) to which the virtual input (c-1) is substituted to the control input (c-3) including the dynamic compensation of the object. The corresponding control input (c-3) may be expressed by Equation 8 (8).

_{In FIG. 7 , τ u} expressed by Equation 8 (8) may represent a driving force of a thruster for advancing an object, and τ _r may represent a rudder input for controlling a moving direction of an object. Since the driving force and the rudder input are means for controlling or regulating the dynamic movement of the object itself, the control input (c-3) may refer to a controller of the object.

In order to improve the control precision of the control input (c-3), the estimated dynamics value of the object and the dynamics estimated value that does not satisfy the matching condition are required, and the estimated value may be obtained by the estimating means of the analysis unit 130 .

The estimating means may use the time delay estimation technique (b) for calculating the estimated value.

The estimation means may estimate the dynamics of the object as in Equation 14 (⑭) using the previous sampling value.

The estimating means may estimate the dynamics that do not satisfy the matching condition as in Equation 15 (⑮) using the previous sampling value.

The dynamics of the object estimated by the estimation means may be provided to the design means and used as some factors of the control input (c-3).

The dynamics estimated by the estimation means, which do not satisfy the matching condition, may be provided to the design means and used as some factors of the control input (c-3).

In view of the control order, the error dynamics (a), the time delay estimation method (b), and the backstepping control method (c) can form a closed-loop controlled relationship.

_{As an example, the result value of the time delay estimation method (b) by the forward distance error D x} , the lateral distance error D _y , the rudder error ψ, the forward velocity error u, the angular velocity error r, etc. corresponding to the output of the error dynamics (a) This can be determined. The result value of the backstepping control technique (c) may be determined by the result value of the time delay estimation technique (b). The output of the error dynamics (a) can be determined by _{the result values τ u} and τ _r of the backstepping control method (c).

8 is a diagram illustrating a computing device according to an embodiment of the present invention. The computing device TN100 of FIG. 8 may be a device (eg, a control device, etc.) described herein.

In the embodiment of FIG. 8 , the computing device TN100 may include at least one processor TN110 , a transceiver device TN120 , and a memory TN130 . In addition, the computing device TN100 may further include a storage device TN140 , an input interface device TN150 , an output interface device TN160 , and the like. Components included in the computing device TN100 may be connected by a bus TN170 to communicate with each other.

The processor TN110 may execute a program command stored in at least one of the memory TN130 and the storage device TN140. The processor TN110 may mean a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor on which methods according to an embodiment of the present invention are performed. The processor TN110 may be configured to implement procedures, functions, methods, and the like described in connection with an embodiment of the present invention. The processor TN110 may control each component of the computing device TN100 .

Each of the memory TN130 and the storage device TN140 may store various information related to the operation of the processor TN110 . Each of the memory TN130 and the storage device TN140 may be configured as at least one of a volatile storage medium and a non-volatile storage medium. For example, the memory TN130 may include at least one of a read only memory (ROM) and a random access memory (RAM).

The transceiver TN120 may transmit or receive a wired signal or a wireless signal. The transceiver TN120 may be connected to a network to perform communication.

On the other hand, the embodiment of the present invention is not implemented only through the apparatus and/or method described so far, and a program for realizing a function corresponding to the configuration of the embodiment of the present invention or a recording medium in which the program is recorded may be implemented. And, such an implementation can be easily implemented by those skilled in the art from the description of the above-described embodiments.

Although the embodiment of the present invention has been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art using the basic concept of the present invention as defined in the following claims are also presented. It belongs to the scope of the invention.

10...Object 110...Converter
130...Analysis Department

Claims (7)

a transformation unit for converting a first coordinate system used for controlling an object moving along a target trajectory into a second coordinate system based on the target trajectory;
an analysis unit for analyzing error dynamics for the object following the target trajectory based on the second coordinate system;
A control device comprising a.
According to claim 1,
The first coordinate system includes any one of an earth coordinate system, a body fixed coordinate system based on the object, and a relative coordinate system based on a third object that is distinguished from the object,
The transform unit converts the first coordinate system into the second coordinate system having a first axis tangent to the target trajectory and a second axis perpendicular to the target trajectory,
The first axis represents the forward distance error or forward speed error of the object,
The second axis is a control device representing a lateral error or a heading angle error or an angular velocity error of the object.
According to claim 1,
The error dynamics analyzed based on the second coordinate system includes at least one of a forward distance error, a forward velocity error, a lateral error, a heading angle error, and an angular velocity error,
The error dynamics includes disturbances that do not satisfy the matching condition,
The analysis unit generates the error dynamics in a form to which a backstepping control technique can be applied using the second coordinate system,
and the analysis unit applies the backstepping control technique to the error dynamics so that the disturbance is suppressed.
According to claim 1,
The analysis unit applies a backstepping control technique to the error dynamics,
The analysis unit generates a backstepping controller of the object that follows the target trajectory,
The backstepping controller includes at least one of an estimated value of nonlinear dynamics of the object and an estimated value of disturbance that does not satisfy a matching condition,
The analysis unit estimates at least one of the estimated value of the nonlinear dynamics and the estimated value of the disturbance by using a time delay estimation technique using a previous sampling time value.
According to claim 1,
The analysis unit generates a backstepping controller of the object by applying a backstepping control technique to the error dynamics,
The analysis unit is a control device for selecting the gain of the back stepping controller within a range that satisfies the condition that the object must advance and the bow angle error is within 90 degrees.
A control method performed by a control device, comprising:
An analysis step of analyzing the dynamics of a submersible having a non-holonomic constraint by introducing a coordinate transformation;
Including; a correction step of correcting the disturbance included in the dynamics of the submersible;
The coordinate transformation is to convert the existing coordinate system used for control of the submersible moving along the target trajectory into a reference trajectory coordinate system based on the target trajectory,
Through the coordinate transformation, it is possible to apply the backstepping control technique,
The correction of the disturbance includes the process of designing or generating a backstepping controller that suppresses the occurrence of the disturbance by applying the backstepping control technique.
7. The method of claim 6,
The backstepping controller of the submersible in which the disturbance is suppressed in the correction step is generated;
An estimation step of estimating at least one of the estimated value of the nonlinear dynamics of the submersible included in the backstepping controller and the estimated value of the disturbance is provided,
The estimating step is a control method of estimating at least one of the estimated value of the nonlinear dynamics and the estimated value of the disturbance using a time delay estimation technique.

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