JP4629504B2 - Apparatus and method for autorotation control of small unmanned helicopter aircraft - Google Patents

Description

  The present invention is a small unmanned vehicle that can autonomously control autorotation (automatic rotation) flight even when engine trouble occurs for some reason during the flight of the helicopter aircraft and rotation energy cannot be supplied to the main rotor. The present invention relates to an autorotation control device and method for a helicopter airframe.

A helicopter aircraft has a range of behavior that is difficult to implement on airplanes, such as forward / backward, left / right, vertical motion, and air suspension (hovering), and has the potential to be used flexibly in various situations. . For example, it is expected to be used in places that are difficult or dangerous for humans to perform, such as inspection work performed at high places such as inspection of power transmission lines, photographing work at a disaster site, or work for detecting landmines. In recent years, attention has been paid to the effectiveness of such helicopter airframes, and research has been conducted to make the helicopter aircraft fly autonomously toward a predetermined target value (see Patent Document 1).
JP 2000-118498 A

  The helicopter airframe maintains its flight by supplying rotational energy to the main rotor, even when it becomes autonomous. If the engine trouble occurs for some reason during the flight of the helicopter airframe and rotation energy cannot be supplied to the main rotor, the helicopter airframe must be lowered. In such cases, the helicopter airframe is not only damaged, but there is a risk of human damage. When making a helicopter aircraft autonomous, it is necessary to take such unforeseen circumstances into consideration and to provide means for minimizing damage even when rotational energy is no longer supplied to the main rotor.

  As a means for that, a means for reducing the descent speed near the ground by mounting a parachute on the helicopter airframe and using it is conceivable. However, helicopter airframes with weight restrictions are a burden, and it is very difficult to achieve this by downsizing. In addition, since the main rotor and tail rotor of the helicopter fuselage rotate even when lowered, there is a possibility that the parachute rope may be entangled with them. Furthermore, the parachute is easily affected by disturbances, and there is a problem that it cannot be controlled when the wind is blowing.

  As another means, a means for switching from autonomous flight to manual control flight and performing autorotation flight is also conceivable. The autorotation flight is a flight in which the helicopter body glides down by rotating the main rotor like a windmill by manipulating the pitch angle of the main rotor blade when rotation energy cannot be supplied to the main rotor. A freewheeling clutch is built into the transmission of the helicopter fuselage so that the main rotor can rotate even when engine trouble occurs. Switching from autonomous flight to manual flight, manipulating the pitch angle of the main rotor blade during the descent, controlling the rotation speed of the main rotor and controlling the descent speed, generating lift near the ground to increase the speed The helicopter can be safely landed close to zero. However, there is a problem that it is very difficult for an amateur to perform autorotation flight, and it is possible for an expert to perform autorotation flight, but helicopter aircraft in flight is always on the ground. There is a problem that the advantage of autonomous flight is lost because it must be monitored.

  Paying attention to such problems, the present invention is able to detect the occurrence of engine trouble and perform safe landing even when engine trouble occurs for some reason during the flight of the helicopter aircraft and rotation energy cannot be supplied to the main rotor. It is an object of the present invention to provide an autorotation control device and control method for a small unmanned helicopter airframe that can autonomously control up to autorotation flight and minimize damage.

  The autorotation control device for a small unmanned helicopter fuselage of the present invention includes a switching unit that performs switching control of connection with various control units that perform engine rotation detection or autorotation control from the rotation speed of the main rotor of the helicopter fuselage, When the engine trouble is determined to occur, the switching unit is connected to the rotation number control unit for controlling the rotation number of the main rotor to reach a target value, and when the rotation number of the main rotor reaches the target value And a descent speed control unit that controls the descent speed of the helicopter body to reach a target value. The rotation speed control unit and the descent speed control unit indicate dynamic characteristics of the helicopter body. Calculates the collective pitch angle based on various model formulas, and autonomously controls using the collective pitch angle A.

  The autorotation control method for a small unmanned helicopter fuselage according to the present invention includes a step of detecting the occurrence of an engine trouble from the rotation speed of the main rotor of the helicopter fuselage, and a control for causing the detected rotation speed of the main rotor to reach a target value. A step of performing, a step of acquiring a descending speed of the helicopter fuselage when the rotational speed of the main rotor reaches a target value, and a step of performing a control for reaching the target descent speed of the acquired helicopter fuselage. The control for reaching the target value of the rotational speed of the main rotor and the control for reaching the target value of the descent speed of the helicopter fuselage are based on various model formulas indicating the dynamic characteristics of the helicopter fuselage. In this method, the angle is calculated and autonomously controlled using the collective pitch angle.

  As is clear from the above, according to the present invention, even when an engine trouble occurs for some reason during the flight of the helicopter fuselage and the rotation energy cannot be supplied to the main rotor, the detection of the engine trouble occurrence and the safety Autorotation flight until landing can be controlled autonomously, and damage can be minimized.

  Hereinafter, the best mode for carrying out the present invention will be described. In addition, this invention is not limited to the range demonstrated below, If it is a range which does not deviate from the summary, it can change and implement suitably.

  Hereinafter, the configuration of each block used in the present embodiment will be briefly described. First, the internal configuration of the autorotation control device will be described. As shown in FIG. 1, the autorotation control apparatus 100 includes a rotation speed control unit 110, a descent speed control unit 120, and a switching unit 130. In the information, it is monitored whether or not the rotational speed of the main rotor has reached the target value, and when it is determined that the target value has not been reached, it is detected that an engine trouble has occurred for some reason. Further, after detecting the occurrence of an engine trouble, the switching unit 130 performs switching control of connection with the rotation speed control unit 110 or the descent speed control unit 120 that performs autorotation control.

  Further, as shown in FIG. 2, the rotational speed control unit 110 is configured to acquire the rotational speed of the main rotor based on the rotational speed acquisition unit 210 that acquires the rotational speed of the main rotor and the model formula indicating the dynamic characteristics of the helicopter airframe. Rotation torque calculation unit 220 that calculates the rotation torque using the first, the first collective pitch angle acquisition unit 230 that acquires the first collective pitch angle based on the rotation torque obtained by the calculation, and the rotational speed control A rotation speed control model storage unit 240 storing a model formula indicating the dynamic characteristics of the helicopter airframe to be used is provided. Here, the first collective pitch angle acquired and output by the rotation speed control unit 110 is a value for adjusting the pitch angle of the main rotor blades so that the rotation speed of the main rotor reaches the target value.

  Further, as shown in FIG. 3, the descent speed control unit 120 calculates the thrust using the obtained descent speed based on the descent speed acquisition unit 310 that obtains the descent speed and the model equation indicating the dynamic characteristics of the helicopter aircraft. Storing a thrust calculation unit 320, a second collective pitch angle acquisition unit 330 for acquiring a collective pitch angle based on the thrust obtained by the calculation, and a model formula indicating the dynamic characteristics of the helicopter body used when performing descent speed control The descent speed control model storage unit 340 is provided. Here, the second collective pitch angle acquired and output by the descent speed control unit 120 is the safe landing of the helicopter body using the rotation speed (rotational energy) of the main rotor that has reached the target value. It is a value that adjusts the pitch angle of the main rotor blade in order to converge to zero, which is the target lowering speed.

  The above is the configuration of the autorotation control apparatus 100. The autorotation control device 100 is basically mounted on the helicopter body 14. Further, as shown in FIG. 4, other configurations mounted on the helicopter fuselage 14 include various sensors 11 for detecting the state of the helicopter fuselage 14 such as the rotational speed and the descending speed of the main rotor of the helicopter fuselage 14, and auto rotation. A control signal processing unit 12 that converts a control value of the collective pitch angle output from the control device 100 into a control signal, and a servo motor 13 that is driven according to the control signal are provided. Various sensors 11, an autorotation control device 100, and a control A control loop is configured among the signal processing unit 12, the servo motor 13, and the helicopter body 14.

  Next, the processing operation of the autorotation control apparatus 100 will be described with reference to FIG. The switching unit 130 of the autorotation control device 100 acquires the rotation speed of the main rotor of the helicopter body 14 from a main rotor rotation speed detection sensor (not shown) included in the various sensors 11, and whether the rotation speed has reached the target value. It is monitoring whether or not. If it is determined that the rotational speed has not reached the target value, it is determined that an engine trouble has occurred for some reason and rotational energy cannot be supplied to the main rotor, and autorotation control is started (START). At this time, the switching unit 130 is connected to the rotation speed control unit 110 to start the rotation speed control mode in the autorotation control. In step 501, the current rotation speed of the main rotor is acquired. In step 502, it is determined whether or not the acquired rotation speed has reached a target value. Since the target value has not been reached at the present time, the process proceeds to step 503. In step 503, the rotational torque calculation unit 220 calculates the rotational torque using the acquired rotational speed of the main rotor based on the rotational torque model and the induced speed model indicating the dynamic characteristics of the helicopter airframe. The rotational torque is a driving force for the rotation of the main rotor of the helicopter body, and the rotational torque of the main rotor is obtained by integrating the rotational torque twice. The rotational torque model is a mathematical model that calculates the rotational torque at that time from the acquired rotational speed of the main rotor, estimated induction speed, and collective pitch angle of the main rotor. Further, the induced speed model is a mathematical model that estimates the induced speed at that time using the acquired main rotor rotational speed and the like in order to estimate the induced speed that cannot be obtained from various sensors. The rotational torque model and the induced speed model are managed by the rotational speed control model storage unit 240.

  Subsequently, in step 504, the first collective pitch angle is acquired from the value of the rotational torque obtained by the calculation. That is, as described above, the rotational torque and the main rotor rotational speed have an integral relationship, and the relationship between the rotational torque and the main rotor collective pitch angle is shown in the rotational torque model. Using these relationships, the collective pitch angle (first collective pitch angle) of the main rotor necessary to reach the desired number of rotations of the main rotor is calculated. Then, the calculated value of the first collective pitch angle is output to the control signal processing unit 12 and converted into a control signal, and then the servo motor 13 is driven in accordance with this value, so that the root of the main rotor blade in the helicopter body 14 is obtained. Adjust the collective pitch angle. As this is adjusted, the rotational speed of the main rotor that is being lowered also changes.

  Thereafter, the process returns to step 501, and the switching unit 130 acquires again the rotation speed of the main rotor of the helicopter body 14 from the main rotor rotation speed detection sensor. In step 502, whether or not the acquired rotation speed has reached the target value. Determine again. If the rotational speed has reached the target value, the process proceeds to step 505, where the switching unit 130 switches to the lowering speed control unit 120 to start the lowering speed control mode in the autorotation control. On the other hand, when the rotational speed has not reached the target value, the switching unit 130 continues the rotational speed control mode and repeats the same processing as described above until the target value is reached.

  In step 505, the switching unit 130 acquires the descending speed of the helicopter body 14 from the descending speed detection sensor (not shown) included in the various sensors 11, and in step 506, whether or not the acquired descending speed has reached the target value. Determine whether. The target value of the descent speed here is a speed necessary for safely landing the helicopter body, and is a value close to zero as much as possible. Since the target value has not been reached at the present time, the process proceeds to step 507. In step 507, the thrust calculation unit 320 calculates the thrust using the acquired descent speed of the helicopter airframe based on the thrust model and the induced speed model indicating the dynamic characteristics of the helicopter airframe. The thrust is a driving force for the helicopter body to ascend and descend, and the difference between the thrust and gravity is integrated once, which is almost the body descending speed. The thrust model is a mathematical model that calculates the thrust at that time from the acquired rotation speed of the main rotor, estimated induction speed, and collective pitch angle of the main rotor. Further, the induced speed model is a mathematical model that estimates the induced speed at that time using the acquired main rotor rotational speed and the like in order to estimate the induced speed that cannot be obtained from various sensors. The thrust model and the induced speed model are managed by the descending speed control model storage unit 340.

  Subsequently, in step 508, the second collective pitch angle is acquired from the thrust value obtained by the calculation. That is, as described above, the thrust and the aircraft lowering speed are in an integral relationship, and the relationship between the thrust and the collective pitch angle of the main rotor is shown in the thrust model. Using these relationships, a collective pitch angle (second collective pitch angle) of the main rotor necessary to reach a desired aircraft lowering speed is calculated. Then, the calculated value of the second collective pitch angle is output to the control signal processing unit 12 and converted into a control signal, and then the servo motor 13 is driven in accordance with the value to thereby control the root of the main rotor blade in the helicopter body 14. Adjust the collective pitch angle. As this is adjusted, the descent speed of the descending helicopter aircraft also changes.

  Thereafter, returning to step 505, the switching unit 130 acquires again the descending speed of the helicopter body 14 from the descending speed detection sensor, and in step 506, determines again whether or not the acquired descending speed has reached the target value. When the descending speed reaches the target value (zero), the helicopter body can be safely landed, so the descending speed control mode is terminated, and the entire autorotation control process is terminated accordingly (END). On the other hand, when the descent speed has not reached the target value (zero), the switching unit 130 continues the descent speed control mode and repeats the same processing as described above until the target value is reached.

  As described above, according to the present embodiment, even when an engine trouble occurs for some reason during the flight of the helicopter aircraft and the rotation energy cannot be supplied to the main rotor, the detection of the engine trouble occurrence and the automatic landing until the safety landing are performed. Rotation flight can be controlled autonomously, and damage can be minimized.

  It should be noted that the autorotation flight of this embodiment has been proved by experiments. The result is shown in FIG. Finally, the descent rate was about -1.5m / s, and safe landing was achieved.

  As is apparent from the above description, according to the autorotation control device and method for a small unmanned helicopter fuselage of the present invention, it is possible to autonomously control autorotation flight until detection of engine trouble occurrence and safe landing. . This is expected to improve the reliability and safety of autonomy of small unmanned helicopter aircraft, such as inspection work performed at high places such as inspection of power transmission lines, shooting work at disaster sites, or work to detect landmines, etc. It can be expected to be used in places that are difficult or dangerous for humans to do.

The block diagram which shows the internal structure of the autorotation control apparatus of this invention Block diagram showing the internal configuration of the rotation speed control unit Block diagram showing the internal configuration of the descent speed controller Control loop in helicopter fuselage with autorotation control device of the present invention The flowchart which shows the process sequence in the autorotation control apparatus of this invention The figure which shows the experimental result of the autorotation flight using the autorotation control apparatus of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Various sensors 12 Control signal processing part 13 Servo motor 14 Helicopter airframe 100 Autorotation control apparatus 110 Rotational speed control part 120 Descent speed control part 130 Switching part 210 Rotational speed control part 220 Rotational torque calculation part 230 1st collective pitch angle acquisition Unit 240 rotational speed control model storage unit 310 descent speed acquisition unit 320 thrust calculation unit 330 second collective pitch angle acquisition unit 340 descent speed control model storage unit

Claims (3)

A switching unit that performs switching control of connection with various control units that perform engine rotation detection or auto-rotation control from the number of rotations of the main rotor of the helicopter fuselage,
A rotation speed control section that is connected to the switching section when it is determined that the engine trouble has occurred, and that controls the rotation speed of the main rotor to reach a target value;
A descent speed control unit that is connected to the switching unit when the rotational speed of the main rotor reaches a target value, and that controls the descent speed of the helicopter body to reach the target value;
The rotational speed control section and the descending speed control unit calculates the collective pitch angle of each based on various model equation showing the dynamic characteristics of the helicopter airframe, autonomously controlled by using the collective pitch angle, also
The rotational speed control unit obtains the rotational speed of the main rotor, and shows the dynamic characteristics of the helicopter fuselage as follows.

And the following induction speed model

On the basis of the obtained rotational speed of the main rotor, and obtaining a first collective pitch angle for causing the rotational speed of the main rotor to reach a target value from the computed rotational torque. Autorotation control device for small unmanned helicopter aircraft. A switching unit that performs switching control of connection with various control units that perform engine rotation detection or auto-rotation control from the number of rotations of the main rotor of the helicopter fuselage,
A rotation speed control section that is connected to the switching section when it is determined that the engine trouble has occurred, and that controls the rotation speed of the main rotor to reach a target value;
A descent speed control unit that is connected to the switching unit when the rotational speed of the main rotor reaches a target value, and that controls the descent speed of the helicopter body to reach the target value;
The rotational speed control unit and the descent speed control unit calculate respective collective pitch angles based on various model expressions indicating the dynamic characteristics of the helicopter airframe, and autonomously control using the collective pitch angles, and
The descending speed control unit acquires the descending speed of the helicopter fuselage, and shows the following thrust model indicating the dynamic characteristics of the helicopter fuselage

And the following induction speed model

And calculating a thrust using the obtained descent speed of the helicopter fuselage, and obtaining a second collective pitch angle for reaching the target value of the descent speed of the helicopter fuselage from the calculated thrust. autorotation control device of small-type non-human helicopter aircraft you. Detecting engine trouble occurrence from the number of rotations of the main rotor of the helicopter fuselage,
Performing a control to reach the target value of the detected rotation speed of the main rotor;
Obtaining a descending speed of the helicopter fuselage when the rotational speed of the main rotor reaches a target value;
A step of performing a control to reach the target value for the descent speed of the acquired helicopter fuselage,
The control to reach the target value for the rotation speed of the main rotor and the control to reach the target value for the descent speed of the helicopter fuselage are performed by calculating the collective pitch angle based on various model equations indicating the dynamic characteristics of the helicopter fuselage. , Autonomously controlled using the collective pitch angle,
In controlling the rotational speed of the main rotor to reach a target value, the rotational torque model below is obtained to obtain the rotational speed of the main rotor and indicate the dynamic characteristics of the helicopter fuselage.

And the following induction speed model

And calculating a rotational torque using the acquired rotation speed of the main rotor, and acquiring a first collective pitch angle that causes the rotation speed of the main rotor to reach a target value from the calculated rotation torque. autorotation control method of small-type non-human helicopter aircraft shall be the feature.

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