Vehicle

Abstract

To obtain a vehicle that does not cause flow interference, does not impose unsteady aerodynamic forces on the aircraft, can improve the accuracy of guidance to the rendezvous point, and can also be miniaturized as a propulsion system. [Solution] The vehicle 1 includes a sensor 2 that obtains tracking information of the rendezvous point, an inertial device 3 that obtains inertial information of the vehicle 1, a cluster engine 4 provided at the rear of the aircraft body 60 and including a plurality of nozzles 6 to 9 that impart translational motion and rotational motion to the aircraft body 60, and an autopilot 5 that calculates an acceleration command for guiding to the rendezvous point based on the tracking information and inertial information, and controls the thrust of the cluster engine 4 including the plurality of nozzles 6 to 9 based on the acceleration command.

Description

Technical Field

[0001] The present disclosure relates to a vehicle that guides to a rendezvous point.

Background Art

[0002] Conventionally, in vehicles including spacecrafts, flying objects, etc. that exceed the speed of sound and receive shock waves from the atmosphere by propulsion, or spacecrafts that perform autonomous guidance in space, as a means for guiding to a rendezvous point, thrust control by thrusters, etc. has been proposed.

[0003] Under such a technical background, for example, in Patent Document 1, as a means for improving the guidance accuracy to a rendezvous point, a technology related to a side thruster that controls the translational motion and rotational motion of an aircraft at a high altitude where the aerodynamic control amount is small has been proposed.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the side thruster disclosed in Patent Document 1, the shock wave generated from the tip of the aircraft to the side and the combustion gas of the side thruster cause flow interference, form a complex Mach system, generate unsteady aerodynamic forces that deteriorate the control characteristics of the aircraft, and there is a problem that the guidance accuracy to the rendezvous point is reduced. Further, when applying a side thruster in space, since it is necessary to arrange a plurality of nozzles before and after the aircraft, there is a problem in miniaturization as a propulsion device.

[0006] This disclosure has been made in view of the above, and aims to provide a vehicle that does not cause flow interference, does not impose unsteady aerodynamic forces on the aircraft, can improve the accuracy of guidance to the rendezvous point, and can achieve miniaturization of the propulsion system. [Means for solving the problem]

[0007] To solve the above-mentioned problems and achieve the objectives, the vehicle according to this disclosure comprises a sensor for obtaining tracking information of a rendezvous point, an inertial device for obtaining inertial information of the vehicle, a cluster engine located at the rear of the aircraft and including a plurality of nozzles that impart translational and rotational motion to the aircraft, and an autopilot that calculates acceleration commands for guiding to the rendezvous point based on the tracking information and inertial information, and controls the thrust of the cluster engine including the plurality of nozzles based on the acceleration commands. [Effects of the Invention]

[0008] The vehicle described herein offers the advantages of not causing flow interference, not subjecting the aircraft to unsteady aerodynamic forces, improving the accuracy of guidance to the rendezvous point, and enabling miniaturization of the propulsion system. [Brief explanation of the drawing]

[0009] [Figure 1] Diagram showing the configuration of the vehicle according to Embodiment 1 [Figure 2] Block diagram showing the configuration of the vehicle control system according to Embodiment 1 [Figure 3] An explanatory diagram showing a state of longitudinal thrust control of a vehicle according to Embodiment 1. [Figure 4] An explanatory diagram showing other states of longitudinal thrust control of a vehicle according to Embodiment 1. [Figure 5] An explanatory diagram showing a state of lateral thrust control of a vehicle according to Embodiment 1. [Figure 6] An explanatory diagram showing other states of lateral thrust control of a vehicle according to Embodiment 1. [Figure 7]Figure showing the configuration of the vehicle according to Embodiment 2 [Figure 8] Block diagram showing the configuration of the control system of the vehicle according to Embodiment 2 [Figure 9] Explanatory diagram showing a state of the longitudinal thrust control of the vehicle according to Embodiment 2 [Figure 10] Explanatory diagram showing another state of the longitudinal thrust control of the vehicle according to Embodiment 2 [Figure 11] Explanatory diagram showing a state of the lateral thrust control of the vehicle according to Embodiment 2 [Figure 12] Explanatory diagram showing another state of the lateral thrust control of the vehicle according to Embodiment 2 [Figure 13] Figure showing the configuration of the vehicle according to Embodiment 3 [Figure 14] Block diagram showing the configuration of the control system of the vehicle according to Embodiment 3 [Figure 15] Explanatory diagram showing a state of the longitudinal thrust control of the vehicle according to Embodiment 3 [Figure 16] Explanatory diagram showing another state of the longitudinal thrust control of the vehicle according to Embodiment 3 [Figure 17] Explanatory diagram showing a state of the lateral thrust control of the vehicle according to Embodiment 3 [Figure 18] Explanatory diagram showing another state of the lateral thrust control of the vehicle according to Embodiment 3

Mode for Carrying Out the Invention

[0010] The vehicle according to the embodiment will be described below with reference to the drawings.

[0011] Embodiment 1. FIG. 1 is a diagram showing the configuration of the vehicle 1 according to Embodiment 1. The left diagram of FIG. 1 is a front sectional view, and the right diagram of FIG. 1 is a rear view. The vehicle 1 includes a fuselage 60, a sensor 2, an inertial device 3, a cluster engine 4, an autopilot 5, nozzles 6 to 9, a fuel storage section 10, an oxidizer storage section 11, a fuel on-off valve 12, an oxidizer on-off valve 13, and an ignition device 14. Reference numeral 15 is the center of gravity of the vehicle 1. In this specification, the direction along the axis O of the fuselage 60 is referred to as the x direction or the axis direction, a certain direction perpendicular to the axis O is referred to as the z direction or the axis perpendicular longitudinal direction, and a direction perpendicular to the x direction and the z direction is referred to as the y direction or the axis perpendicular lateral direction. The vehicle 1 is a vehicle including a spacecraft, an aircraft, etc. that receive a shock wave from the atmosphere exceeding the speed of sound by its own driving force, or a vehicle as a spacecraft that performs autonomous guidance in space. The vehicle 1 may be an unmanned or manned aircraft that flies.

[0012] The cluster engine 4 has a plurality of nozzles 6 to 9 arranged at the rear of the fuselage 60, an ignition device 14, a fuel on-off valve 12, and an oxidizer on-off valve 13. The cluster engine 4 gives the fuselage 60 translational motion and rotational motion. The oxidizer storage section 11 that stores the oxidizer and the plurality of nozzles 6 to 9 are connected by an oxidizer supply path including the oxidizer on-off valve 13. The fuel storage section 10 that stores the fuel and the plurality of nozzles 6 to 9 are connected by a fuel supply path including the fuel on-off valve 12. In each of the nozzles 6 to 9, when an air-fuel mixture of fuel and oxidizer is ignited by the ignition device 14, a detonation wave is generated to burn the air-fuel mixture, and the gas generated by the combustion of the air-fuel mixture is ejected rearward of the fuselage 60 to generate thrust.

[0013] Sensor 2 tracks the rendezvous point and transmits the tracking information of the rendezvous point to Autopilot 5. Inertial device 3 transmits the inertial information of vehicle 1 to Autopilot 5. Based on the tracking information of the rendezvous point and the inertial information of vehicle 1, Autopilot 5 calculates guidance signals necessary to correct errors to the expected meeting point with the rendezvous point, calculates acceleration commands and angular velocity commands based on the guidance signals, and calculates thrust commands for the multiple nozzles 6-9 of the cluster engine 4. In the cluster engine 4, the fuel on / off valve 12, the oxidizer on / off valve 13, and the ignition device 14 are controlled based on the thrust commands to generate thrust.

[0014] Figure 2 is a block diagram showing the configuration of the control system of Vehicle 1 according to Embodiment 1. Sensor 2 observes and tracks the rendezvous point 16 and transmits the tracking information of the rendezvous point 16 to the autopilot 5. Inertial device 3 transmits inertial information, including the acceleration and angular velocity of Vehicle 1, to the autopilot 5. The autopilot 5 comprises a tracking filter 5a, an acceleration command calculation unit 5b, and an autopilot calculation unit 5c. The tracking filter 5a calculates guidance signals necessary to correct errors from the tracking information of the rendezvous point 16 and the inertial information of Vehicle 1 to the expected meeting point with the rendezvous point 16. The acceleration command calculation unit 5b calculates acceleration commands and angular velocity commands from the guidance signals. The autopilot calculation unit 5c calculates thrust commands for multiple nozzles 6 to 9 of the cluster engine 4 based on the acceleration commands and angular velocity commands. The autopilot calculation unit 5c outputs the thrust commands for the multiple nozzles 6 to 9 to the cluster engine 4. The cluster engine 4 generates thrust by controlling the fuel valve 12, the oxidizer valve 13, and the ignition device 14 based on thrust commands from nozzles 6-9. At the same time, the cluster engine 4 controls angular velocity and other parameters to ensure that the acceleration generated in the vehicle 1 by the thrust of the cluster engine 4 follows the acceleration command, and that the vehicle 1 maintains tracking of the rendezvous point 16 and that the attitude angle does not diverge. By continuously performing these operations, the vehicle 1 performs autonomous flight toward the rendezvous point 16.

[0015] Figure 3 is an explanatory diagram showing a state of longitudinal thrust control of Vehicle 1 according to Embodiment 1. The left side of Figure 3 shows the rendezvous point 16 of Vehicle 1, the middle side of Figure 3 is a front view of Vehicle 1, and the right side of Figure 3 is a rear view of Vehicle 1. Figure 4 is an explanatory diagram showing another state of longitudinal thrust control of Vehicle 1 according to Embodiment 1. The left side of Figure 4 shows the rendezvous point 16 of Vehicle 1, and the right side of Figure 4 is a front view of Vehicle 1. Longitudinal thrust control corresponds to thrust control in the z direction.

[0016] Figures 3 and 4 show the rendezvous point 16 of vehicle 1, the velocity vector 17 of the rendezvous point 16, the velocity vector 18 of vehicle 1, the error 19 between the velocity vector 17 of the rendezvous point 16 and the velocity vector 18 of vehicle 1, the sensor aiming angle 20 in the pitch direction of sensor 2, the thrust 21 generated using nozzle 7, the thrust 22 generated using nozzle 8, the total thrust 23 of thrust 21 and thrust 22, the z-direction distance 24 from the thrust axis of the total thrust 23 to the center of gravity 15, the pitching moment 25 generated by the total thrust 23, the component force 26 in the direction of the velocity vector 18 in the total thrust 23, and the vertical component force 27 of the velocity vector 18 in the total thrust 23.

[0017] In Figure 3, Vehicle 1 tracks the rendezvous point 16 using sensor 2. If there is an error 19 in the z direction between the velocity vector 17 of the rendezvous point 16 and the velocity vector 18 of Vehicle 1, thrusts 21 and 22 are generated in, for example, nozzles 7 and 8 of the cluster engine 4 to reduce the error 19. The thrust axis of the total thrust 23 (thrusts 21 and 22) is located 24 units away from the center of gravity 15 in the z direction, resulting in a pitching moment 25 being generated in the vehicle 60. The magnitude Mz of the pitching moment 25 of Vehicle 1 can be expressed as shown in equation (1). The magnitude Mz of the pitching moment 25 is the magnitude of the moment around an axis extending in the y direction from the center of gravity 15. T1 is the magnitude of the total thrust 23, and L1 corresponds to the distance 24 from the thrust axis of the total thrust 23 to the center of gravity 15.

[0018] Mz = T1·L1 ···(1)

[0019] When a pitching moment 25 is generated in the aircraft 60, the attitude angle of the aircraft 60 in the pitch direction changes as shown in Figure 4, and a component force 26 of the total thrust 23 acts in the direction of the velocity vector 18 of the vehicle 1, and a component force 27 of the total thrust 23 acts in the vertical direction perpendicular to the velocity vector 18. Component force 26 acts as acceleration in the x direction, and component force 27 acts as acceleration in the z direction. The acceleration ax in the direction of the velocity vector 18 generated in the vehicle 1, the acceleration az in the vertical direction perpendicular to the aircraft axis generated in the vehicle 1, the angular acceleration q in the pitch direction generated in the vehicle 1, and the change in the pitch attitude angle Δθ of the vehicle 1 can be expressed as shown in equation (2). θ is the attitude angle of the vehicle 1 in the pitch direction, Izz is the moment of inertia of the vehicle 1 in the pitch direction, and Δt is the elapsed time.

[0020] ax = T1·cos(θ) az = T1·sin(θ) q = Mz / Izz Δθ = q·Δt ...(2)

[0021] The z-direction acceleration generated in vehicle 1 reduces the z-direction error 19. At the same time, the attitude angle of the aircraft 60 is controlled by angular velocity control, etc., so that the sensor beam angle 20 in the pitch direction remains within the beam angle limit of sensor 2, so that vehicle 1 can continue to track the rendezvous point 16. This control can be expressed as shown in equation (3). λp is the magnitude of the sensor beam angle 20 in the pitch direction of sensor 2 with respect to the rendezvous point 16, and λmax is the beam angle limit of sensor 2.

[0022] λp ≤ λmax ···(3)

[0023] Figure 5 is an explanatory diagram showing a state of lateral thrust control of Vehicle 1 according to Embodiment 1. The left side of Figure 5 shows the rendezvous point 16 of Vehicle 1, the middle side of Figure 5 is a front view of Vehicle 1, and the right side of Figure 5 is a rear view of Vehicle 1. Figure 6 is an explanatory diagram showing another state of lateral thrust control of Vehicle 1 according to Embodiment 1. The left side of Figure 6 shows the rendezvous point 16 of Vehicle 1, and the right side of Figure 6 is a front view of Vehicle 1. Lateral thrust control corresponds to thrust control in the y-direction.

[0024] Figures 5 and 6 show the rendezvous point 16 of vehicle 1, the velocity vector 17 of the rendezvous point 16, the velocity vector 18 of vehicle 1, the error 19 between the velocity vector 17 of the rendezvous point 16 and the velocity vector 18 of vehicle 1, the sensor directional angle 28 in the yaw direction of sensor 2, the thrust 22 generated using nozzle 8, the thrust 29 generated using nozzle 9, the total thrust 30 of thrust 22 and thrust 29, the y-direction distance 31 from the thrust axis of the total thrust 30 to the center of gravity 15, the yawing moment 32 generated by the total thrust 30, the component force 33 of the velocity vector 18 in the total thrust 30, and the vertical and lateral component force 34 of the velocity vector 18 in the total thrust 30.

[0025] In Figure 5, Vehicle 1 tracks the rendezvous point 16 using sensor 2. If there is an error 19 in the y-direction between the velocity vector 17 of the rendezvous point 16 and the velocity vector 18 of Vehicle 1, thrusts 22 and 29 are generated in, for example, nozzles 8 and 9 of the cluster engine 4 to reduce the error 19. The thrust axis of the total thrust 30 (thrusts 22 and 29) is located 31 units away from the center of gravity 15 in the y-direction, thus generating a yawing moment 32 in the vehicle 60. The magnitude My of the yawing moment 32 of Vehicle 1 can be expressed as shown in equation (4). The magnitude My of the yawing moment 32 is the magnitude of the moment around an axis extending in the z-direction from the center of gravity 15. T2 is the magnitude of the total thrust 30, and L2 corresponds to the distance 31 from the thrust axis of the total thrust 30 to the center of gravity 15.

[0026] My=T2·L2 ···(4)

[0027] When a yawing moment 32 is generated in the aircraft 60, the attitude angle of the aircraft 60 in the yaw direction changes as shown in Figure 6. A component force 33 of the total thrust 30 acts in the direction of the velocity vector 18 of the vehicle 1, and a component force 34 of the total thrust 30 acts in the vertical and lateral directions of the velocity vector 18. Component force 33 acts as acceleration in the x direction, and component force 34 acts as acceleration in the y direction. The acceleration ax in the direction of the velocity vector 18, the acceleration ay in the vertical and lateral directions of the vehicle 1, the angular acceleration r in the yaw direction of the vehicle 1, and the change in the yaw attitude angle Δψ of the vehicle 1 can be expressed as shown in equation (5). ψ is the attitude angle of the vehicle 1 in the yaw direction, Iyy is the moment of inertia of the vehicle 1 in the yaw direction, and Δt is the elapsed time.

[0028] ax = T²·cos(ψ) ay = T²·sin(ψ) r=My / Iyy Δψ=r·Δt ...(5)

[0029] The y-direction error 19 is reduced when vehicle 1 experiences acceleration in the y-direction. At the same time, the attitude angle of the aircraft 60 is controlled by angular velocity control, etc., so that the yaw direction sensor beam angle 28 remains within the beam angle limit of sensor 2, so that vehicle 1 can continue to track the rendezvous point 16. This control can be expressed as shown in equation (6). λy is the magnitude of the yaw direction sensor beam angle 28 of sensor 2 with respect to the rendezvous point 16, and λmax is the beam angle limit of sensor 2.

[0030] λy ≤ λmax ···(6)

[0031] As described above, according to Embodiment 1, the aircraft body 60 is equipped with a cluster engine 4 that provides translational and rotational motion to the rear of the aircraft. Therefore, the combustion gases of the cluster engine 4 do not cause interference between the shock waves and the flow generated from the front of the aircraft to the side, and do not generate unsteady aerodynamic forces on the aircraft body 60. This has the effect of improving the accuracy of guidance to the rendezvous point 16.

[0032] Furthermore, the nozzles 6-9, which provide translational and rotational motion to the aircraft 60, can be concentrated at the rear of the aircraft, and the number of nozzles can be reduced compared to side thrusters, thus enabling miniaturization of the propulsion system.

[0033] Embodiment 2. Figure 7 shows the configuration of Vehicle 1 according to Embodiment 2. The left side of Figure 7 is a front cross-sectional view, and the right side of Figure 7 is a rear view. In Embodiment 2, a plurality of rotor blades 35 and a plurality of steering devices 36 are added to the configuration of Embodiment 1.

[0034] Figure 8 is a block diagram showing the configuration of the control system of Vehicle 1 according to Embodiment 2. In Figure 8, a steering device 36 is added to the control system of Embodiment 1 shown in Figure 2. Sensor 2 observes and tracks the rendezvous point 16 and transmits the tracking information of the rendezvous point 16 to the autopilot 5. Inertial device 3 transmits inertial information, including the acceleration and angular velocity of Vehicle 1, to the autopilot 5. Tracking filter 5a calculates guidance signals necessary to correct errors from the tracking information of the rendezvous point 16 and the inertial information of Vehicle 1 to the expected meeting point with the rendezvous point 16. Acceleration command calculation unit 5b calculates acceleration commands and angular velocity commands from the guidance signals. Autopilot calculation unit 5c calculates thrust commands for multiple nozzles 6-9 of the cluster engine 4 and rudder angle commands for multiple rotor blades 35 based on the acceleration commands and angular velocity commands. The autopilot calculation unit 5c outputs thrust commands for multiple nozzles 6-9 to the cluster engine 4 and rudder angle commands for multiple control surfaces 35 to multiple steering devices 36. Based on the thrust commands for nozzles 6-9, the cluster engine 4 controls the fuel on / off valve 12, the oxidizer on / off valve 13, and the ignition device 14 to generate thrust. The steering devices 36 generate aerodynamic force by applying rudder angles to the control surfaces 35. At the same time, the acceleration generated in the vehicle 1 by the thrust of the cluster engine 4 and the aerodynamic force of the control surfaces 35 is made to follow the acceleration command, and angular velocity control is also performed to ensure that the vehicle 1 maintains tracking of the rendezvous point 16 and that the attitude angle does not diverge. By continuously performing the above operations, the vehicle 1 performs autonomous flight toward the rendezvous point 16.

[0035] Figure 9 is an explanatory diagram showing a state of longitudinal thrust control of Vehicle 1 according to Embodiment 2. The left side of Figure 9 shows the rendezvous point 16 of Vehicle 1, the middle side of Figure 9 is a front view of Vehicle 1, and the right side of Figure 9 is a rear view of Vehicle 1. Figure 10 is an explanatory diagram showing another state of longitudinal thrust control of Vehicle 1 according to Embodiment 2. The left side of Figure 10 shows the rendezvous point 16 of Vehicle 1, and the right side of Figure 10 is a front view of Vehicle 1. Longitudinal thrust control corresponds to thrust control in the z direction.

[0036] Figures 9 and 10 show the rendezvous point 16 of vehicle 1, the velocity vector 17 of the rendezvous point 16, the velocity vector 18 of vehicle 1, the error 19 between the velocity vector 17 of the rendezvous point 16 and the velocity vector 18 of vehicle 1, the sensor aiming angle 20 in the pitch direction of sensor 2, the thrust 21 generated using nozzle 7, the thrust 22 generated using nozzle 8, the total thrust 23 of thrust 21 and thrust 22, and the thrust of the total thrust 23. The distance 24 from the force axis to the center of gravity 15, the pitching moment 25 generated by the total thrust 23, the component force 26 in the direction of the velocity vector 18 in the total thrust 23, the vertical component force 27 of the velocity vector 18 in the total thrust 23, the pitch angle 37 of the rotor blade 35, the aerodynamic force 38 generated on the rotor blade 35, the distance 39 in the x-direction from the point of application of the aerodynamic force 38 to the center of gravity 15, and the pitching moment 40 generated by the aerodynamic force 38 are shown.

[0037] In Figure 9, Vehicle 1 tracks the rendezvous point 16 using sensor 2. If there is an error 19 in the z direction between the velocity vector 17 of the rendezvous point 16 and the velocity vector 18 of Vehicle 1, thrusts 21 and 22 are generated in the cluster engine 4, for example, nozzles 7 and 8, to reduce the error 19. The steering system 36 generates aerodynamic force 38 by applying a pitch rudder angle 37 to the control surfaces 35. The thrust axis of the total thrust 23 (thrusts 21 and 22) is located 24 units away from the center of gravity 15 in the z direction, and the point of application of the aerodynamic force 38 is located 39 units away from the center of gravity 15 in the x direction. As a result, pitching moments 25 and 40 are generated in the aircraft 60. The magnitude Mz of the pitching moments 25 and 40 of Vehicle 1 can be expressed as shown in equation (7). T1 is the magnitude of the total thrust 23, and L1 corresponds to the distance 24 from the thrust axis of the total thrust 23 to the center of gravity 15. Furthermore, Nw represents the magnitude of the aerodynamic force 38, δp represents the magnitude of the pitch rudder angle 37, and L3 corresponds to the distance 39 in the x-direction from the point of application of the aerodynamic force 38 to the center of gravity 15.

[0038] Mz=T1·L1+Nw·cos(δp)·L3 ···(7)

[0039] When pitching moments 25 and 40 are generated in the aircraft 60, the attitude angle of the aircraft 60 in the pitch direction changes as shown in Figure 10. A component force 26 of the total thrust 23 acts in the direction of the velocity vector 18 of the vehicle 1, and a component force 27 of the total thrust 23 acts in the vertical direction perpendicular to the velocity vector 18. Component force 26 acts as acceleration in the x direction, and component force 27 acts as acceleration in the z direction. In addition, the aerodynamic force 38 of the control surface 35 also acts as acceleration in the x and z directions. The acceleration ax in the direction of the velocity vector 18 generated in the vehicle 1, the acceleration az in the vertical direction perpendicular to the aircraft axis generated in the vehicle 1, the angular acceleration q in the pitch direction generated in the vehicle 1, and the change in the pitch attitude angle Δθ of the vehicle 1 can be expressed as shown in equation (8). θ is the attitude angle of the vehicle 1 in the pitch direction, Izz is the moment of inertia of the vehicle 1 in the pitch direction, and Δt is the elapsed time.

[0040] ax=T1 cos(θ)+Nw sin(θ-δp) az=T1·sin(θ)-Nw·cos(θ-δp) q = Mz / Izz Δθ = q·Δt ...(8)

[0041] The error 19 is reduced when vehicle 1 experiences acceleration in the z direction. At that time, the attitude angle of the aircraft 60 is controlled by angular velocity control, etc., so that the sensor heading angle 20 in the pitch direction remains within the heading angle limit of sensor 2, so that vehicle 1 can continue to track the rendezvous point 16. This control can be expressed as shown in equation (3) above.

[0042] Figure 11 is an explanatory diagram showing a state of lateral thrust control of Vehicle 1 according to Embodiment 2. The left side of Figure 11 shows the rendezvous point 16 of Vehicle 1, the middle side of Figure 11 is a front view of Vehicle 1, and the right side of Figure 11 is a rear view of Vehicle 1. Figure 12 is an explanatory diagram showing another state of lateral thrust control of Vehicle 1 according to Embodiment 2. The left side of Figure 12 shows the rendezvous point 16 of Vehicle 1, and the right side of Figure 12 is a front view of Vehicle 1. Lateral thrust control corresponds to thrust control in the y-direction.

[0043] Figures 11 and 12 show the rendezvous point 16 of vehicle 1, the velocity vector 17 of the rendezvous point 16, the velocity vector 18 of vehicle 1, the error 19 between the velocity vector 17 of the rendezvous point 16 and the velocity vector 18 of vehicle 1, the sensor directional angle 28 in the yaw direction of sensor 2, the thrust 22 generated using nozzle 8, the thrust 29 generated using nozzle 9, the total thrust 30 of thrust 22 and thrust 29, and the thrust of the total thrust 30. The following are shown: the y-direction distance 31 from the axis to the center of gravity 15, the yawing moment 32 generated by the total thrust 30, the component force 33 of the velocity vector 18 in the total thrust 30, the vertical and lateral component force 34 of the velocity vector 18 in the total thrust 30, the yaw angle 41 of the rotor blade 35, the aerodynamic force 42 generated on the rotor blade 35, the x-direction distance 43 from the point of application of the aerodynamic force 42 to the center of gravity 15, and the yawing moment 44 generated by the aerodynamic force 42.

[0044] In Figure 11, Vehicle 1 tracks the rendezvous point 16 using sensor 2. If there is an error 19 in the y-direction between the velocity vector 17 of the rendezvous point 16 and the velocity vector 18 of Vehicle 1, thrusts 22 and 29 are generated in the cluster engine 4, for example, nozzles 8 and 9, to reduce the error 19. The steering system 36 generates aerodynamic force 42 by applying a yaw angle 41 to the control surfaces 35. The thrust axis of the total thrust 30 (thrusts 22 and 29) is 31 units away from the center of gravity 15, and the point of application of the aerodynamic force 42 is 43 units away from the center of gravity 15, so yawing moments 32 and 44 are generated in the aircraft 60. The magnitude My of the yawing moments 32 and 44 of Vehicle 1 can be expressed as shown in equation (9). T2 is the magnitude of the total thrust 30, and L2 corresponds to the distance 31 from the thrust axis of the total thrust 30 to the center of gravity 15. Nw is the magnitude of the aerodynamic force 42, δy is the magnitude of the yaw angle 41, and L4 corresponds to the distance 43 in the x-direction from the point of application of the aerodynamic force 42 to the center of gravity 15.

[0045] My=T2·L2+Nw·cos(δy)·L4 ···(9)

[0046] When yawing moments 32 and 44 are generated in the aircraft 60, the attitude angle of the aircraft 60 in the yaw direction changes as shown in Figure 12. A component force 33 of the total thrust 30 acts in the direction of the velocity vector 18 of the vehicle 1, and a component force 34 of the total thrust 30 acts in the vertical and lateral direction of the velocity vector 18. Component force 33 acts as acceleration in the x direction, and component force 34 acts as acceleration in the y direction. In addition, the aerodynamic force 42 of the control surface 35 also acts as acceleration in the x and y directions. The acceleration ax in the direction of the velocity vector 18 generated in the vehicle 1, the acceleration ay in the vertical and lateral direction of the aircraft axis generated in the vehicle 1, the angular acceleration r in the yaw direction generated in the vehicle 1, and the change in the yaw attitude angle Δψ of the vehicle 1 can be expressed as shown in equation (10). ψ is the yaw attitude angle of the vehicle 1, Iyy is the moment of inertia of the vehicle 1 in the yaw direction, and Δt is the elapsed time.

[0047] ax=T2·cos(ψ)+Nw·sin(ψ-δy) ay=T2·sin(ψ)-Nw·cos(ψ-δy) r=My / Iyy Δψ=r·Δt ...(10)

[0048] The error 19 is reduced when vehicle 1 experiences acceleration in the y-direction. At that time, the attitude angle of the aircraft 60 is controlled by angular velocity control, etc., so that the yaw direction sensor beam angle 28 remains within the beam angle limit of sensor 2, so that vehicle 1 can continue tracking the rendezvous point 16. This control can be expressed as shown in equation (6) above.

[0049] As described above, according to Embodiment 2, the aircraft body 60 is equipped with a cluster engine 4 that provides translational and rotational motion to the rear of the aircraft. Therefore, the combustion gases of the cluster engine 4 do not cause interference between the shock waves and the flow generated from the front of the aircraft to the side, and do not generate unsteady aerodynamic forces on the aircraft body 60. This has the effect of improving the accuracy of guidance to the rendezvous point 16.

[0050] Furthermore, the nozzles 6-9, which provide translational and rotational motion to the aircraft 60, can be concentrated at the rear of the aircraft, and the number of nozzles can be reduced compared to side thrusters, thus enabling miniaturization of the propulsion system.

[0051] Furthermore, in addition to the thrust from the cluster engine 4, aerodynamic forces from the control surfaces 35 can be used as a controller to impart translational and rotational motion to the aircraft 60, thus further improving the accuracy of guidance to the rendezvous point 16.

[0052] Embodiment 3. Figure 13 shows the configuration of Vehicle 1 according to Embodiment 3. The left side of Figure 13 is a front cross-sectional view, and the right side of Figure 13 is a rear view. In Embodiment 3, a plurality of attitude control devices 45 are added to the configuration of Embodiment 1. The attitude control devices 45 include reaction wheels, magnetic torquers, or control momentum gyros, etc.

[0053] Figure 14 is a block diagram showing the configuration of the control system of the vehicle 1 according to Embodiment 3. In Figure 14, an attitude control device 45 is added to the control system of Embodiment 1 shown in Figure 2. Sensor 2 observes and tracks the rendezvous point 16 and transmits the tracking information of the rendezvous point 16 to the autopilot 5. Inertial device 3 transmits inertial information, including the acceleration and angular velocity of the vehicle 1, to the autopilot 5. Tracking filter 5a calculates guidance signals necessary to correct errors from the tracking information of the rendezvous point 16 and the inertial information of the vehicle 1 to the predicted meeting point with the rendezvous point 16. Acceleration command calculation unit 5b calculates acceleration commands and angular velocity commands from the guidance signals. Autopilot calculation unit 5c calculates thrust commands for the multiple nozzles 6-9 of the cluster engine 4 and device control commands for the attitude control device 45 based on the acceleration commands and angular velocity commands. The autopilot calculation unit 5c outputs thrust commands for multiple nozzles 6-9 to the cluster engine 4 and device control commands for the attitude control device 45 to multiple attitude control devices 45. Based on the thrust commands for nozzles 6-9, the cluster engine 4 controls the fuel on / off valve 12, the oxidizer on / off valve 13, and the ignition device 14 to generate thrust. The attitude control devices 45 also generate control responses to the aircraft 60. At the same time, the acceleration generated in the vehicle 1 by the thrust of the cluster engine 4 and the control responses of the attitude control devices 45 is made to follow the acceleration command, and angular velocity control is also performed to ensure that the vehicle 1 maintains tracking of the rendezvous point 16 and that the attitude angle does not diverge. By continuously performing the above operations, the vehicle 1 performs autonomous flight toward the rendezvous point 16.

[0054] Figure 15 is an explanatory diagram showing a state of longitudinal thrust control of Vehicle 1 according to Embodiment 3. The left side of Figure 15 shows the rendezvous point 16 of Vehicle 1, the middle side of Figure 15 is a front view of Vehicle 1, and the right side of Figure 15 is a rear view of Vehicle 1. Figure 16 is an explanatory diagram showing another state of longitudinal thrust control of Vehicle 1 according to Embodiment 3. The left side of Figure 16 shows the rendezvous point 16 of Vehicle 1, and the right side of Figure 16 is a front view of Vehicle 1. Longitudinal thrust control corresponds to thrust control in the z direction.

[0055] Figures 15 and 16 show the rendezvous point 16 of vehicle 1, the velocity vector 17 of the rendezvous point 16, the velocity vector 18 of vehicle 1, the error 19 between the velocity vector 17 of the rendezvous point 16 and the velocity vector 18 of vehicle 1, the sensor aiming angle 20 in the pitch direction of sensor 2, the thrust 21 generated using nozzle 7, the thrust 22 generated using nozzle 8, the total thrust 23 of thrust 21 and thrust 22, the distance 24 from the thrust axis of the total thrust 23 to the center of gravity 15, the pitching moment 25 generated by the total thrust 23, the component force 26 in the direction of the velocity vector 18 in the total thrust 23, the vertical component force 27 of the velocity vector 18 in the total thrust 23, the control response 46 of the attitude control device 45, the x-direction distance 47 from the point of application of the control response 46 to the center of gravity 15, and the pitching moment 48 generated by the control response 46.

[0056] In Figure 15, Vehicle 1 tracks the rendezvous point 16 using sensor 2. If there is an error 19 in the z direction between the velocity vector 17 of the rendezvous point 16 and the velocity vector 18 of Vehicle 1, thrusts 21 and 22 are generated in the cluster engine 4, for example, nozzles 7 and 8, to reduce the error 19. The attitude control device 45 also generates a control response 46. The thrust axis of the total thrust 23 (thrusts 21 and 22) is located 24 units away from the center of gravity 15 in the z direction, and the point of application of the control response 46 is located 47 units away from the center of gravity 15 in the x direction. As a result, pitching moments 25 and 48 are generated in the vehicle 60. The magnitude Mz of the pitching moments 25 and 48 of Vehicle 1 can be expressed as shown in equation (11). T1 is the magnitude of the total thrust 23, and L1 corresponds to the distance 24 from the thrust axis of the total thrust 23 to the center of gravity 15. Nd is the magnitude of the control response 46, and L5 corresponds to the x-direction distance 47 from the point of application of force of the control response 46 to the center of gravity 15.

[0057] Mz = T1·L1 + Nd·L5 ···(11)

[0058] When pitching moments 25 and 48 are generated in the aircraft 60, the attitude angle of the aircraft 60 in the pitch direction changes as shown in Figure 16. A component force 26 of the total thrust 23 acts in the direction of the velocity vector 18 of the vehicle 1, and a component force 27 of the total thrust 23 acts in the vertical direction perpendicular to the velocity vector 18. Component force 26 acts as acceleration in the x direction, and component force 27 acts as acceleration in the z direction. The control response 46 of the attitude control device 45 also acts as acceleration in the x and z directions. The acceleration ax in the direction of the velocity vector 18, the acceleration az perpendicular to the axis of the vehicle 1, the angular acceleration q in the pitch direction of the vehicle 1, and the change in the pitch attitude angle Δθ of the vehicle 1 can be expressed as shown in equation (12). θ is the pitch attitude angle of the vehicle 1, Izz is the moment of inertia of the vehicle 1 in the pitch direction, and Δt is the elapsed time.

[0059] ax = T1·cos(θ) + Nd·sin(θ) az = T1·sin(θ) - Nd·cos(θ) q=My / Izz Δθ = q·Δt ...(12)

[0060] The error 19 is reduced when vehicle 1 experiences acceleration in the z direction. At that time, the attitude angle of the aircraft 60 is controlled by angular velocity control, etc., so that the sensor heading angle 20 in the pitch direction remains within the heading angle limit of sensor 2, so that vehicle 1 can continue to track the rendezvous point 16. This control can be expressed as shown in equation (3) above.

[0061] Figure 17 is an explanatory diagram showing a state of lateral thrust control of Vehicle 1 according to Embodiment 3. The left side of Figure 17 shows the rendezvous point 16 of Vehicle 1, the middle side of Figure 17 is a front view of Vehicle 1, and the right side of Figure 17 is a rear view of Vehicle 1. Figure 18 is an explanatory diagram showing another state of lateral thrust control of Vehicle 1 according to Embodiment 3. The left side of Figure 18 shows the rendezvous point 16 of Vehicle 1, and the right side of Figure 18 is a front view of Vehicle 1. Lateral thrust control corresponds to thrust control in the y-direction.

[0062] Figures 17 and 18 show the rendezvous point 16 of vehicle 1, the velocity vector 17 of the rendezvous point 16, the velocity vector 18 of vehicle 1, the error 19 between the velocity vector 17 of the rendezvous point 16 and the velocity vector 18 of vehicle 1, the sensor directional angle 28 in the yaw direction of sensor 2, the thrust 22 generated using nozzle 8, the thrust 29 generated using nozzle 9, the total thrust 30 of thrust 22 and thrust 29, the y-direction distance 31 from the thrust axis of the total thrust 30 to the center of gravity 15, the yawing moment 32 generated by the total thrust 30, the component force 33 in the direction of the velocity vector 18 in the total thrust 30, the vertical and lateral component force 34 of the velocity vector 18 in the total thrust 30, the control response 49 of the attitude control device 45, the distance 50 from the point of application of the control response 49 to the center of gravity 15, and the yawing moment 51 generated by the control response 49.

[0063] In Figure 17, Vehicle 1 tracks the rendezvous point 16 using sensor 2. If there is an error 19 in the y-direction between the velocity vector 17 of the rendezvous point 16 and the velocity vector 18 of Vehicle 1, thrusts 22 and 29 are generated in nozzles 8 and 9 of the cluster engine 4 to reduce the error 19. The attitude control device 45 also generates a control response 49. The thrust axis of the total thrust 30 (thrusts 22 and 29) is 31 units away from the center of gravity 15, and the point of application of the control response 49 is 50 units away from the center of gravity 15. As a result, yawing moments 32 and 51 are generated in the vehicle 60. The magnitude My of the yawing moments 32 and 51 of Vehicle 1 can be expressed as shown in equation (13). T2 is the magnitude of the total thrust 30, and L2 corresponds to the distance 31 from the thrust axis of the total thrust 30 to the center of gravity 15. Nd is the magnitude of the control response 49, and L6 corresponds to the distance 50 in the x-direction from the point of application of the control response 49 to the center of gravity 15.

[0064] My = T2·L2 + Nd·L6 ···(13)

[0065] When yawing moments 32 and 51 are generated in the aircraft 60, the attitude angle of the aircraft 60 in the yaw direction changes as shown in Figure 18. A component force 33 of the total thrust 30 acts in the direction of the velocity vector 18 of the vehicle 1, and a component force 34 of the total thrust 30 acts perpendicular to the velocity vector 18. Component force 33 acts as acceleration in the x direction, and component force 34 acts as acceleration in the y direction. The control response 49 of the attitude control device 45 also acts as acceleration in the x and y directions. The acceleration ax in the direction of the velocity vector 18, the acceleration ay in the direction perpendicular to the axis of the vehicle 1, the angular acceleration r in the yaw direction of the vehicle 1, and the change in the yaw attitude angle Δψ of the vehicle 1 can be expressed as shown in equation (14). ψ is the yaw attitude angle of the vehicle 1, Iyy is the moment of inertia in the yaw direction of the vehicle 1, and Δt is the elapsed time.

[0066] ax = T²·cos(ψ) + Nd·sin(ψ) ay = T2·sin(ψ) - Nd·cos(ψ) r = Mz / Iyy Δψ=r·Δt ...(14)

[0067] The error 19 is reduced when vehicle 1 experiences acceleration in the y-direction. At that time, the attitude angle of the aircraft 60 is controlled by angular velocity control, etc., so that the yaw direction sensor beam angle 28 remains within the beam angle limit of sensor 2, so that vehicle 1 can continue tracking the rendezvous point 16. This control can be expressed as shown in equation (6) above.

[0068] As described above, according to Embodiment 3, the aircraft body 60 is equipped with a cluster engine 4 that provides translational and rotational motion to the rear of the aircraft. Therefore, the combustion gases of the cluster engine 4 do not cause interference between the shock waves and the flow generated from the front of the aircraft to the side, and do not generate unsteady aerodynamic forces on the aircraft body 60. This has the effect of improving the accuracy of guidance to the rendezvous point 16.

[0069] Furthermore, the nozzles 6-9, which provide translational and rotational motion to the aircraft 60, can be concentrated at the rear of the aircraft, and the number of nozzles can be reduced compared to side thrusters, thus enabling miniaturization of the propulsion system.

[0070] Furthermore, in addition to the thrust from the cluster engine 4, the control response from the attitude control device 45 can be used as a controller to impart translational and rotational motion to the aircraft 60, thus further improving the accuracy of guidance to the rendezvous point 16.

[0071] The configurations shown in the embodiments described above are merely examples of the content of this disclosure, and can be combined with other known technologies, and the configurations of each embodiment can be combined. It is also possible to omit or modify parts of the configuration without departing from the gist of this disclosure. [Explanation of Symbols]

[0072] 1 Vehicle, 2 Sensors, 3 Inertial device, 4 Cluster engine, 5 Autopilot, 5a Tracking filter, 5b Acceleration command calculation unit, 5c Autopilot calculation unit, 6-9 Nozzles, 10 Fuel compartment, 11 Oxidizer compartment, 12 Fuel on / off valve, 13 Oxidizer on / off valve, 14 Ignition device, 15 Center of gravity, 16 Rendezvous point, 17,18 Velocity vector, 19 Error, 20,28 Sensor beam angle, 21,22,29 Thrust, 23,30 Total thrust, 24,31,39,43,47,50 Distance, 25,40,48 Pitching moment, 26,27,33,34 Force component, 32,44,51 Yawing moment, 35 Control surface, 36 Steering device, 37 Pitch angle, 38,42 Aerodynamic force, 41 Yaw angle, 45; attitude control device, 46, 49; control response, 60; airframe, O; axis.

Claims

1. A sensor that obtains tracking information for the rendezvous point, An inertial device that obtains inertial information of the vehicle, A cluster engine located at the rear of the aircraft, which includes multiple nozzles that impart translational and rotational motion to the aircraft, The autopilot includes calculating an acceleration command for guiding to the rendezvous point based on the tracking information and the inertial information, and controlling the thrust of the cluster engine, including the plurality of nozzles, based on the acceleration command. A vehicle characterized by the following:

2. It further comprises a control surface and a steering device for controlling the control surface, The autopilot controls the steering system and the aerodynamic forces of the control surfaces based on the tracking information and the inertial information. The vehicle according to feature 1.

3. The aircraft further comprises an attitude control device for controlling the attitude of the aircraft, The autopilot controls the control response of the attitude control device based on the tracking information and the inertial information. The vehicle according to feature 1.

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