JP5976530B2 - Control device - Google Patents

Description

  The present invention relates to a control device, and more particularly to a control device suitable for being applied to a system including speed saturation.

Conventionally, for attitude control of underwater vehicles etc., the rudder angle command obtained by performing proportional integral differential control on the difference between the target attitude and the current attitude is given to the rudder, and the hull attitude is set to the target attitude It is done to follow.
FIG. 11 shows a block diagram of a general conventional control device 50. As shown in FIG. 11, the difference between the attitude θp of the hull 51 and the target command θp ^* is input to the PID control unit 52, and the steering angle command φ ^* is generated. The rudder angle command φ ^* is given to a rudder control system that controls the rudder 54, and is controlled so that the rudder angle of the rudder 54 follows the rudder angle command φ ^* . In this way, when the rudder angle changes based on the rudder angle command φ ^* , the attitude of the hull 51 also changes, and the attitude θp of the hull 51 approaches the target command θp ^* .

JP-A-8-282589

In recent years, it has been required to further improve the responsiveness of the hull to the target posture. However, a rudder provided in an underwater vehicle or the like has a speed saturation element that cannot follow a sudden change in a rudder angle command. For this reason, when a steering angle command in a region exceeding a predetermined amplitude or a region where the frequency exceeds a predetermined frequency is input to the rudder control system, the actual steering angle cannot follow such a command, and the speed saturation does not occur. It will occur.
When speed saturation occurs, a relatively large phase delay occurs, and the response of the rudder is extremely deteriorated. As a result, for example, the hull vibrates and the control system becomes unstable.
Furthermore, in an underwater vehicle or the like where such speed saturation is a concern, the control gain of the PID control unit 52 provided in the hull control system cannot be increased, and the operating area is limited. The responsiveness was further deteriorated.

  Conventionally, as a measure for eliminating such speed saturation, only a passive solution of limiting the range of the rudder angle command given to the rudder to a frequency region and an amplitude region where speed saturation does not occur has been taken.

  The present invention has been made in view of such circumstances, and is capable of expanding a control region to an operation range where speed saturation has occurred, and capable of improving control stability and followability. The purpose is to provide.

  The present invention is applied to a system in which speed saturation occurs in an actuator that gives an operation amount to a control target, and a main loop that generates a position command for matching the control target to a target state; And a minor loop for following the operation amount of the control device, comprising: a speed saturation compensation means to which the position command generated in the main loop is input, wherein the speed saturation compensation means There is a function that defines a limit value in advance, speed limit value setting means for setting a speed limit value corresponding to the previous value of the position command using the function, input from the previous value of the position command and the main loop A speed calculation means for calculating a command speed from the current value of the position command that has been performed, and the command speed calculated by the speed calculation means When the speed limit value is less than or equal to the speed limit value set by the speed limit value setting means, the current value of the position command is used as a compensation position command, and when the command speed exceeds the speed limit value, the position command A compensation means for generating a compensation position command such that the command speed is equal to or less than the speed limit value using the previous value of the control value, and a control device for outputting the compensation position command as input information of the minor loop are provided.

  According to the control device, the speed limit value is set according to the position command from the main loop, and the position command output to the actuator is limited within the speed limit value. Thus, by limiting the speed according to the position, it is possible to give a reasonable position command to the minor loop that is the control system of the actuator. As a result, the phase delay of the actuator can be reduced, and for example, the control gain of the PID controller in the main loop can be increased. Therefore, control of the control target, that is, the operation area in the main loop can be expanded, and the response of the control target can be improved. Furthermore, according to the present invention, since the speed saturation compensation means is provided in series in the signal input line for inputting the position command from the main loop to the minor loop, the configuration is simple and it can be easily applied to existing circuits. Benefits are gained.

In the above control device, for example, when the position is an origin that is the center position of the movable range of the actuator, the speed limit value takes a value equal to or less than the maximum speed that the actuator can output, and the position is When the maximum value and the minimum value are taken, the speed limit value is zero, and the speed limit value is a value less than or equal to the maximum speed that the actuator can output in a range where the position is greater than the minimum value and less than the maximum value. It is preferable that the function takes
Furthermore, the function is preferably continuous in position, velocity and acceleration. By setting it as such a function, a position command can be changed smoothly and a stable actuator control can be performed. That is, as can be seen from the relationship of “force acting on the machine = acceleration × mass”, the force can be smoothly applied to the machine by making the position, speed, and acceleration continuous. Thereby, for example, generation of sound and impact on the machine can be suppressed, which is preferable from the viewpoint of machine protection and noise prevention.

  According to the present invention, it is possible to expand the control region to the operation range where the speed saturation has occurred, and to achieve the effect of improving the stability of control and followability.

It is a control block diagram of the control apparatus which concerns on one Embodiment of this invention. It is a functional block diagram of the speed saturation compensation part which concerns on one Embodiment of this invention. It is the figure shown about the speed of the rudder angle command. It is the figure which showed the phase-plane trajectory of the function which the speed limit value setting part which concerns on one Embodiment of this invention has. It is the figure which showed the relationship between the steering angle command at the time of giving a steering angle command to the conventional control apparatus shown in FIG. 11, and an actual steering angle. It is the figure which showed the relationship between the steering angle command speed and the actual steering angular speed at the time of giving the same steering angle command as FIG. 5 to the conventional control apparatus shown in FIG. In the control device shown in FIG. 1, a diagram showing a relationship between a compensated steering angle command, an actual steering angle, and a steering angle command when the same steering angle command as in FIG. 5 is input to the speed saturation compensation unit. is there. In the control apparatus shown in FIG. 1, the figure which showed the relationship between the compensation steering angle command, the actual steering angle, and the steering angle command speed when the same steering angle command as FIG. 5 was input into the speed saturation compensation part. It is. It is the figure which showed the responsiveness of (a) pitch angle, (b) rudder angle, and (c) rudder angular velocity of a hull when giving a pitch angle command to the control apparatus shown in FIG. It is the figure which showed the phase surface orbit of the function of the other example which the speed limit value setting part which concerns on one Embodiment of this invention has. It is the figure which showed an example of the block diagram of the conventional control apparatus.

Hereinafter, a control device according to each embodiment of the present invention will be described with reference to the drawings. The present invention is widely applied to systems in which speed saturation occurs in an actuator that gives an operation amount to a control target. Examples of the actuator include a rudder and a wing, and examples of the control target include a ship, an underwater vehicle, a rocket, and an aircraft.
Hereinafter, an embodiment in which an underwater vehicle is assumed as a control target and a rudder is assumed as an actuator will be described. However, the control device of the present invention is not limited to this range, and as described above, speed saturation occurs. It is widely used in the resulting system.

Hereinafter, the control apparatus 1 which concerns on one Embodiment of this invention is demonstrated using figures.
FIG. 1 is a control block diagram of the control device 1 according to the present embodiment. As shown in FIG. 1, the underwater vehicle to which the control device 1 is applied controls the attitude of the hull 2 by changing the rudder angle of the rudder 10.

The control device 1 generates a rudder angle command ri [n] to the rudder 10 for making the attitude θp of the hull 2 coincide with the target attitude θp ^* , and a rudder angle command ri generated in the main loop 20. [n] is input and the speed saturation compensation unit 40 that outputs the compensation control command ro [n], and the compensation steering angle command ro [n] output from the speed saturation compensation unit 40 follows the actual steering angle of the rudder 10 And a minor loop 30 is provided as a main configuration.

The main loop 20 includes a feedback unit 21 that feeds back the attitude θp of the hull 2, a difference calculation unit 22 that calculates a difference between the attitude θp and the target attitude θp ^*, and a proportional-integral-derivative for the output of the difference calculation unit 22. A PID control unit 23 that performs control and generates a rudder angle command ri [n] for the rudder 10 is provided as a main configuration.

The rudder angle command ri [n] output from the PID control unit 23 is compensated by the speed saturation compensation unit 40 so that the position control of the hull 2 does not become unstable due to speed saturation, and the compensated rudder angle command is compensated rudder. The angle command ro [n] is input to the minor loop 30 which is the control system of the rudder 10. Details of the velocity saturation compensation unit 40 will be described later.
The minor loop 30 controls the rudder so that the actual rudder angle matches the compensated rudder angle command ro [n]. Specifically, the minor loop 30 includes a feedback unit 31 that feeds back the actual rudder angle of the rudder 10, and a difference calculation unit 32 that calculates a difference between the compensated rudder angle command ro [n] and the actual rudder angle of the rudder 10. The output of the difference calculation unit 32 is given to the rudder 10 as a rudder command. Thus, the rudder angle of the rudder 10 is controlled to follow the compensation rudder angle command ro [n].
In this way, when the actual rudder angle of the rudder 10 changes based on the compensated rudder angle command ro [n], the attitude of the hull 2 also changes, and the attitude θp of the hull 2 approaches the target command θp ^*. Become.

  FIG. 2 is a functional block diagram of the speed saturation compensator 40. As shown in FIG. 2, the speed saturation compensation unit 40 includes a position limiter 41, a speed limit value setting unit 42, a speed calculation unit 43, and a compensation unit 44 as main components.

The position limiter 41 limits and outputs the rudder angle command ri [n] input from the main loop 20 within the maximum angle range of the rudder 10 (−r _lim ≦ ri [n] ≦ + r _lim ). It is.
The speed limit value setting unit 42 has a function Fx (r) that defines a speed limit value for the steering angle (position) in advance, and the previous value ro [ The speed limit value v _max corresponding to n−1] is acquired. Here, the previous value ro [n-1] of the rudder angle command is a rudder angle command before one sampling period. The function Fx (r) will be described later.

The speed calculation unit 43 calculates the speed of the steering angle command from the current value ri [n] of the steering angle command output from the position restriction unit 41 and the previous value ro [n-1] of the steering angle command. The rudder angle command speed v [n] is given by the following equation (1).
v [n] = (ri [n] -ro [n-1]) / dt (1)
Here, dt is a sampling period.
FIG. 3 is a diagram showing the speed v [n] of the steering angle command. As shown in FIG. 3, the speed v [n] of the rudder angle command is obtained by calculating points ri [n] and ro [n-1] in a coordinate space in which the horizontal axis represents time and the vertical axis represents the rudder angle command. This is the slope of the connecting straight line.

When the speed v [n] of the rudder angle command calculated by the speed calculating unit 43 is equal to or less than the speed limit value v _max set by the speed limit value setting unit 42, the compensation unit 44 The value ri [n] is output to the minor loop 30 as the compensation position command ro [n]. On the other hand, the speed of the steering angle command calculated by the speed calculator 43 v [n] is, if it is exceeded the speed limit value v _max set by the speed limit value setting unit 42, the speed of the steering angle command v A steering angle command is calculated such that [n] is equal to or less than the speed limit value _vmax , and this steering angle command is output to the minor loop 30 as a compensated steering angle command ro [n]. For example, the compensation unit 44 calculates a compensated steering angle command ro [n] using the following equation (2).

ro [n] = ro [n−1] + sign (v _max ) × v _max · dt (2)

Next, the function Fx (r) in the speed limit value setting unit 42 will be described.
The function Fx (r) is a function that defines a speed limit value _vmax for the rudder angle (position) r. For example, when the rudder angle (position) r takes the origin (the center position of the movable range of the rudder), When the speed limit value v _max is the maximum speed v _lim that the rudder 10 can output and the steering angle (position) r is the maximum value + r _lim and the minimum value −r _lim , the speed limit value v _max is zero, In the range where the position r is greater than the minimum value and less than the maximum value (−r _lim <r <+ r _lim ), the speed limit value v _max takes a value less than or equal to the maximum speed v _lim that the rudder 10 can produce. It is said that.
Here, the function Fx (r) preferably has a continuous steering angle (position), speed, and acceleration.

  An example of the function Fx (r) is shown in the following formula (3), and FIG. 4 shows a phase plane trajectory of the function Fx (r) expressed by the following formula (3).

The function Fx (r) expressed by the above equation (3) is a relational expression of free vibration that draws a sine wave with respect to the maximum angle value r _lim that the rudder 10 can take and the maximum speed v _lim that the rudder can take. (4) is modified.

Thus, in the present embodiment, the speed limit value v _max when the rudder angle command ro [n−1] is substituted into r of the function Fx (r) represented by the above formula (3) is acquired, By limiting the speed of the rudder angle command so as not to exceed the speed limit value _vmax , the attitude control of the hull is stabilized.

Next, the operation content of the control device 1 according to the present embodiment will be described.
First, the position of the hull is fed back, the difference between the hull attitude θp and the target attitude θp ^* is calculated by the difference calculation unit 22, and the PID control unit 23 performs proportional integral differential control on this difference. A rudder angle command ri [n] for the rudder 10 is generated. The steering angle command ri [n] is output to the speed saturation compensation unit 40.

In the position restriction unit 41 of the speed saturation compensation unit 40, the rudder angle command ri [n] is restricted within the maximum angle range of the rudder 10 (−r _lim ≦ ri [n] ≦ + r _lim ), and then the speed restriction. The value is output to the value setting unit 42.
The speed limit value setting unit 42 sets a speed limit value for the previous value ro [n−1] of the steering angle command using a function Fx (r) that defines the speed limit value for the steering angle command. Specifically, the speed limit value v _max is obtained by substituting the previous value ro [n−1] of the steering angle command into the position r in the above-described equation (3), and this speed limit value v _max is set as the speed limit value v _max . It outputs to the compensation part 44.
On the other hand, in the speed calculation unit 43, the current value ri [n] of the rudder angle command output from the position limiting unit 41 and the previous value ro [n-1] of the rudder angle command are calculated using the above equation (1). From the above, the speed of the steering angle command is calculated, and the speed of the steering angle command is output to the compensation unit 44.

The compensation unit 44, the speed of the steering angle command calculated by the speed calculator 43 v [n] is equal to or less than set speed limit v _max to the speed limit value setting unit 42, the current steering angle command The value ri [n] is output to the minor loop 30 as the compensation position command ro [n].
On the other hand, the speed of the steering angle command calculated by the speed calculator 43 v [n] is, if it is exceeded the speed limit value v _max set by the speed limit value setting unit 42, the speed of the steering angle command v A steering angle command such that [n] is equal to or less than the speed limit value _vmax is calculated using the above equation (2), and this steering angle command is output to the minor loop 30 as a compensated steering angle command ro [n]. Is done.

In the minor loop 30, the difference between the compensation rudder angle command ro [n] and the actual rudder angle is calculated by the difference calculation unit 32, and this difference is given to the rudder 10 as a rudder command. Thus, the rudder angle of the rudder 10 is controlled to follow the compensation rudder angle command ro [n]. In this way, when the rudder angle changes based on the compensated rudder angle command ro [n], the attitude of the hull 2 also changes, and the attitude θp of the hull 2 approaches the target command θp ^* .

As described above, according to the control device 1 according to the present embodiment, the speed saturation compensation unit 40 sets the speed limit value according to the steering angle command (position command), and the speed of the steering angle command is the speed. A compensation rudder angle command is set so as to be less than the limit value. As a result, a reasonable steering angle command can be given to the rudder 10, and phase delay can be suppressed.
Further, in the control device 1, the speed saturation compensation unit 40 is provided in series on a signal input line through which a steering angle command is input from the main loop 20 to the minor loop 30. The advantage is that it is easy to apply.

  FIG. 5 is a diagram showing the relationship between the steering angle command and the actual steering angle when the steering angle command is given to the conventional control device 50 shown in FIG. FIG. 6 is a diagram showing the relationship between the steering angle command speed and the actual steering angular speed when the same steering angle command as in FIG. 5 is given to the conventional control device 50 shown in FIG. FIG. 7 shows the compensation steering angle command and the actual steering angle when the same steering angle command as in FIG. 5 is input to the speed saturation compensation unit 40 in the control device 1 according to the present embodiment shown in FIG. It is the figure which showed the relationship between steering angle command. FIG. 8 shows a control rudder angle command when the same rudder angle command as FIG. 5 is input to the speed saturation compensator 40 in the control device 1 according to the present embodiment shown in FIG. It is the figure which showed the relationship with a steering angle command speed.

  As shown in FIGS. 5 and 6, in the conventional control device 50, a delay of about a half cycle occurs in the response to the rudder angle command and the rudder angle command speed, and it can be seen that the followability is extremely poor. On the other hand, as shown in FIGS. 7 and 8, according to the control device 1 according to the present embodiment, there is almost no delay in the response to the steering angle command and the steering angle command speed, and the response of the steering angle. It can be seen that the movement is substantially the same along the rudder angle command. Thus, according to the control apparatus 1 which concerns on this embodiment, high responsiveness is realizable compared with the past.

Further, FIG. 9 shows the pitch angle of the hull (see FIG. 9A) and the rudder angle (see FIG. 9B) when a pitch angle command is given to the control device 1 according to the present embodiment shown in FIG. FIG. 10 is a diagram showing the response of the steering angular velocity (see FIG. 9C).
As shown in FIG. 9, according to the control device 1 according to the present embodiment shown in FIG. 1, the rudder angle and the rudder angular speed immediately follow the compensated rudder angle command and the compensated rudder angle command speed. The pitch angle of the hull 2 also shows excellent followability to the command. In particular, as shown in FIG. 9C, even when the fluctuation of the steering angle command speed is very large, the compensated steering angle command speed is limited within a predetermined range. It can be seen that the compensation steering angle command can be followed quickly.
Thus, according to the control apparatus 1 which concerns on this embodiment, the followable | trackability of a rudder angle and a rudder angular velocity can be improved conventionally, and, thereby, the followable | trackability of hull attitude control can be improved. .

In the present embodiment, the function Fx (r) is set to the speed limit value v _max using a function that draws a circular phase surface trajectory as shown in FIG. 3, but the function Fx (r) Is not limited to this example. For example, in the above equation (4), a function in which square is changed to third power, fourth power, or the like may be used. Further, a function for drawing a phase plane trajectory having a shape as shown in FIG. 10 may be used. By setting the speed limit value _{v max} by using a function to draw the phase plane trajectory of the shape shown in FIG. 10, a range of _{-r E ≦ r ≦ + r E} , takes the speed limit value _{v max} rudder 10 It can be set to the maximum speed v _lim to obtain. Thereby, the position range in which the rudder 10 moves at the maximum speed v _lim can be widened as compared with the function that draws the circular phase plane trajectory shown in FIG.
In this way, the function Fx (r) has a maximum speed v _lim that the speed limit value v _max can be output by the rudder 10 at the rudder angle (position) r, that is, the center position of the movable range of the rudder 10, or When the steering angle (position) r is the maximum value + r _lim and the minimum value −r _lim , the speed limit value v _max is zero, and the position r is greater than the minimum value and less than the maximum value. In the range (−r _lim <r <+ r _lim ), the speed limit value v _max may be a function that takes a value less than or equal to the maximum speed v _lim that the steering angle 10 can be output. The designer can freely set the function.

DESCRIPTION OF SYMBOLS 1 Control apparatus 2 Hull 10 Rudder 20 Main loop 21, 31 Feedback part 22, 32 Difference calculating part 23 PID control part 30 Minor loop 40 Speed saturation compensation part 41 Position restriction part 42 Speed restriction value setting part 43 Speed calculation part 44 Compensation part

Claims (3)

This is applied to a system in which speed saturation occurs in an actuator that gives an operation amount to a control object, and a main loop that generates a position command for matching the control object to a target state, and an operation amount of the actuator in the position command A control device including a minor loop for following,
A velocity saturation compensation means for inputting the position command generated in the main loop;
The speed saturation compensation means includes
A speed limit value setting means for setting a speed limit value corresponding to the previous value of the position command by using a function that defines a speed limit value for the position in advance;
Speed calculating means for calculating a command speed from the previous value of the position command and the current value of the position command input from the main loop;
When the command speed calculated by the speed calculation unit is equal to or less than the speed limit value set by the speed limit value setting unit, the current value of the position command is used as a compensation position command, and the command speed is Compensation means for calculating a compensation position command so that the command speed is equal to or less than the speed limit value using the previous value of the position command when the speed limit value is exceeded,
A control device that outputs the compensation position command as input information of the minor loop.   In the function, when the position is the origin which is the center position of the movable range of the actuator, the speed limit value is a maximum speed that can be output by the actuator or less, and the position has a maximum value and a minimum value. In this case, the speed limit value is zero, and the speed limit value is a function that takes a value less than or equal to the maximum speed that the actuator can output in a range where the position is greater than the minimum value and less than the maximum value. The control apparatus according to 1. The control device according to claim 2, wherein the function is continuous in position, velocity, and acceleration.

Images