JP2985616B2 - Thrust control method of solid fuel rocket - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling the thrust of a solid fuel rocket, which is used to control the magnitude of thrust in the solid fuel rocket.

[0002]

2. Description of the Related Art As shown in FIG. 2, for example, the solid fuel rocket described above has a combustion chamber 51 loaded with a solid fuel 52 and an end face combustion of the solid fuel 52 provided continuously with the combustion chamber 51. There is a solid fuel rocket 50 having a nozzle 53 for injecting combustion gas generated by the rocket.

[0003] In such a solid fuel rocket 50, the basic characteristic that the combustion speed of the solid fuel 52 depends on the combustion pressure, and the combustion pressure depends on the ratio of the combustion area to the nozzle throat area. Because there is
Conventionally, when controlling the thrust of the solid fuel rocket 50, for example, the nozzle 53 is made variable and the area of the nozzle throat 53a is changed to control the combustion pressure in the combustion chamber 51. Thus, the magnitude of the thrust is controlled by changing the combustion speed of the solid fuel 52.

[0004] Regarding this type of ram rocket thrust control method, see, for example, “Handbook of augmentation plate aerospace engineering”.
The description is given on pages 644 to 652, published by Maruzen on April 25, 1983, by the Japan Society for Aeronautics and Astronautics.

[0005]

However, in the above-described conventional method for controlling the thrust of a solid fuel rocket,
As the end face combustion of the solid fuel 52 proceeds in the direction indicated by the arrow in the figure, the volume of the combustion gas increases, that is, the space Sp occupied by the combustion gas in the combustion chamber 51 increases. 5
Responsiveness of the burning speed to the change in area of 3a is reduced. For example, when the solid fuel rocket 50 is a small rocket for controlling the attitude of a flying object, it greatly affects the attitude control system of the entire flying object. There is a problem that it has no effect, and solving this problem has been a conventional problem.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems. For example, when applied to a small rocket for controlling the attitude of a flying object, the attitude control of the flying object is always stabilized. It is an object of the present invention to provide a thrust control method for a solid fuel rocket that can be performed.

[0007]

SUMMARY OF THE INVENTION The present invention controls the thrust of a solid fuel rocket having a combustion chamber charged with solid fuel and burning the solid fuel, and a variable nozzle capable of expanding and reducing the nozzle throat area. A thrust controller that changes the nozzle throat area of the variable nozzle according to a thrust control command, and calculates the mass flow rate of the combustion gas ejected from the variable nozzle using the combustion pressure in the combustion chamber and the nozzle throat area, Gain and phase input to the thrust controller by the gain adjustment function unit and the time constant adjustment function unit provided in the thrust controller based on the predicted volume increase amount of the combustion gas in the combustion chamber obtained by time integration of To make the control characteristics of the feedback control system including the thrust controller constant. Configuration and are characterized in that the,
The configuration of the thrust control method for the solid fuel rocket is used as means for solving the above-mentioned conventional problems.

[0008] Here, the mass flow rate dm / dt of the combustion gas ejected from the variable nozzle is obtained by Expression 1 using the combustion pressure Pc and the nozzle throat area At.

[0009]

[Equation 1] _{dm / dt = C D · At} · Pc However, _{C D} is a constant.

[0010]

In the thrust control method for a solid fuel rocket according to the present invention, when the combustion of the solid fuel proceeds and the volume of the combustion gas increases, that is, when the space occupied by the combustion gas in the combustion chamber increases, the thrust increases. The controller calculates the mass flow rate of the combustion gas ejected from the variable nozzle using the combustion pressure in the combustion chamber and the nozzle throat area, and obtains the predicted volume increase of the combustion gas in the combustion chamber by time integration of the mass flow rate. Followed by
Based on the predicted volume increase, each of the gain and the phase input to the thrust controller is adjusted by the gain adjustment function unit and the time constant adjustment function unit of the thrust controller, so that the feedback control including the thrust controller is performed. The control characteristics of the system become constant, and eventually
The response of the combustion speed to the change in the area of the nozzle throat is almost constant from the initial stage to the final stage of the combustion of the solid fuel.

[0011]

FIG. 1 shows an embodiment of a thrust control method for a solid fuel rocket according to the present invention.

As shown in FIG. 1, the solid fuel rocket 1 includes a combustion chamber 3 in which a solid fuel 2 is loaded and the solid fuel 2 is burned, and a variable nozzle 4 provided at a rear end of the combustion chamber 3. The variable nozzle 4 is provided so that the area of the nozzle throat 4a can be enlarged or reduced.

The solid fuel rocket 1 includes a thrust controller 10 constituting a feedback control system, a pressure sensor 6 provided in the combustion chamber 3, and a throat opening detector 7 provided in the variable nozzle 4. .

In this case, the thrust controller 10 includes a gain setting device 11 for setting a gain, a phase compensator 12 for providing stability to the operation of the variable nozzle 4, and a power amplifying unit for providing a drive signal to the variable nozzle 4. 13, and a gain adjusting function unit 14 provided between the gain setting unit 11 and both the detection units of the pressure sensor 6 and the throat opening degree detector 7 to adjust the gain input to the thrust controller 10. This thrust controller 10 is provided between the phase compensator 12 and both of the pressure sensor 6 and the throat opening degree detector 7.
And a time-constant adjustment function unit 15 for adjusting the phase inside the control signal.

That is, in this feedback control system,
The thrust controller 10 multiplies the combustion pressure in the combustion chamber detected by the pressure sensor 6 with the area of the nozzle throat 4a fed back from the throat opening degree detector 7 and an experimentally obtained constant to output the variable nozzle 4. The mass flow rate of the combustion gas to be ejected is calculated, and the predicted volume increase of the combustion gas in the combustion chamber 3 is obtained by the time integration of the mass flow rate.
The gain adjustment function unit 14 and the time constant adjustment function unit 15 of the thrust controller 10 adjust each of the gain and the phase to stabilize the control characteristics of the feedback control system. The responsiveness of the burning speed to the change in the area of the throat 4a can be made substantially constant from the early stage to the last stage of the combustion of the solid fuel 2.

In such a solid fuel rocket 1, thrust is generated by injecting a combustion gas generated by end combustion of the solid fuel 2 in the combustion chamber 3 from the variable nozzle 4.

At this time, according to the thrust control command input to the feedback control system, the thrust controller 10
A drive signal is given to the variable nozzle 4 from the power amplifying unit 13 of this embodiment, and the opening of the nozzle throat 4a is adjusted by the operation of the variable nozzle 4, so that the solid fuel rocket 1 Will occur.

When the end face combustion of the solid fuel 2 proceeds in the direction of the arrow shown in the figure, the volume of the combustion gas increases, that is, the space S occupied by the combustion gas in the combustion chamber 3 increases, but the thrust of the feedback control system increases. Controller 10
First, the combustion pressure in the combustion chamber 3 detected by the pressure sensor 6 and the throat opening degree detector 7 of the variable nozzle 4
The mass flow rate of the combustion gas ejected from the variable nozzle 4 is calculated by multiplying the nozzle throat area fed back from the above with an experimentally obtained constant.

Next, the predicted volume increase of the combustion gas in the combustion chamber 3 is obtained by integrating this mass flow rate with time.

Subsequently, based on the predicted volume increase, in the thrust controller 10, the gain adjusting function unit 14 adjusts the gain, and the time constant adjusting function unit 15 adjusts the phase. Therefore, the control characteristics of the feedback control system are stabilized.

As a result, the responsiveness of the combustion speed to the change in the area of the nozzle throat 4a does not decrease even when the end face combustion of the solid fuel 2 proceeds, and is substantially constant from the initial combustion to the final combustion of the solid fuel 2. Will be done.

Therefore, if the above-described thrust control method is employed when the solid fuel rocket 1 is a small rocket for controlling the attitude of a flying object, the attitude control of the flying object is always performed stably.

The detailed configuration of the thrust control method for a solid fuel rocket according to the present invention is not limited to the above-described embodiment.

[0024]

As described above, the thrust control method for a solid fuel rocket according to the present invention has the above-described configuration. Therefore, the response of the solid fuel combustion speed to the change in the area of the nozzle throat is as follows. It is almost constant from the beginning of combustion to the end of combustion.For example, when it is used in a small rocket for controlling the attitude of a flying object, it is extremely excellent that its attitude control can always be performed stably. The effect is brought about.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a simplified cross section of a solid fuel rocket showing an embodiment of a thrust control method for a solid fuel rocket according to the present invention.

FIG. 2 is an explanatory cross-sectional view of a solid fuel rocket showing a conventional thrust control method for the solid fuel rocket.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Solid fuel rocket 2 Solid fuel 3 Combustion chamber 4 Variable nozzle 4a Nozzle throat 10 Thrust controller 14 Gain adjustment function unit 15 Time constant adjustment function unit

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F02K 9/08 F02K 9/26 F02K 9/86

Claims (1)

(57) [Claims] When performing thrust control of a solid fuel rocket having a combustion chamber charged with solid fuel and burning said solid fuel and a variable nozzle capable of expanding and reducing a nozzle throat area, said thrust control command is used to control said variable. A thrust controller that changes the nozzle throat area of the nozzle is provided,
Using the combustion pressure in the combustion chamber and the nozzle throat area, calculate the mass flow rate of the combustion gas ejected from the variable nozzle,
Based on the predicted volume increase of the combustion gas in the combustion chamber obtained by time-integrating the mass flow, the gain controller and the time constant controller provided in the thrust controller are input to the thrust controller. A thrust control method for a solid fuel rocket, wherein a gain and a phase are adjusted to make control characteristics of a feedback control system including the thrust controller constant.