Posture control system

Abstract

This aims to create an attitude control system that can respond appropriately to pilot inputs during maneuvers such as turning and landing. [Solution] An attitude control device installed in a radio-controlled model airplane, which is a controlled object that is operated based on control signals received from an external device, includes a calculation unit that selectively outputs a first aileron control signal input as a control signal and a second aileron control signal calculated to maintain the horizontal position of the controlled object based on the roll angle of the controlled object. The calculation unit selects and outputs the second aileron control signal when the function is instructed to be ON by a function setting signal received from an external source, the first aileron control signal is a signal indicating neutral, and the roll angle of the controlled object is within a set angle.

Description

Technical Field

[0001] The present invention relates to an attitude control device mounted on an object to be controlled that is controlled based on a control signal received from the outside.

Background Art

[0002] Some flight control systems for remotely controlling objects to be controlled such as model airplanes and drones have an attitude control function as described in, for example, Patent Documents 1 and 2 below. Patent Document 1 describes a control method for a multicopter that can obtain the pleasure of flying while reducing the complexity of operating the multicopter. Patent Document 2 describes that the flying object has a function of maintaining itself horizontal.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] As an attitude control device for a flying object, there is one equipped with a flight assistance function for beginners to intermediate users. For example, there is one that automatically performs horizontal return control by a horizontal flight automatic return function so as to maintain a horizontal attitude. This detects the roll angle and pitch angle of the airframe from a gyro sensor (angular velocity sensor) and an acceleration sensor, and automatically controls the aileron and elevator so as to achieve a horizontal attitude. During the control of this horizontal flight automatic return, the control inputs of the aileron and elevator are limited to a predetermined angle to prevent excessive input.

[0005] In a normal turn, the pilot (user) tilts the aircraft by operating the aileron stick on the transmitter, then returns the aileron stick to neutral, and then pulls the elevator stick to turn the aircraft. After the turn is complete, the aileron stick is moved in the opposite direction to return the aircraft to level flight, ending the turn operation. However, if a turn operation is attempted during the above-mentioned automatic return-to-level flight control, the aileron input is limited, making it impossible to turn to the desired angle, resulting in a wide turn.

[0006] Furthermore, while it is necessary to input the elevator to raise the nose during landing, the elevator may automatically operate to return the aircraft to a horizontal position, causing the nose to drop and making a stable landing difficult. Furthermore, during automatic horizontal flight return control, the pitch angle is limited and elevator operation is not very effective, making it difficult to make fine adjustments to altitude and speed using the elevator stick.

[0007] Therefore, the present invention provides an attitude control device that has a flight assistance function separate from the above-mentioned automatic horizontal flight return function, and that can respond appropriately to pilot operations during turns, landings, etc. [Means for solving the problem]

[0008] The attitude control device according to the present invention is an attitude control device mounted on a radio-controlled model airplane, which is a controlled object that is operated based on control signals received from an external device, and comprises a calculation unit that selectively outputs a first aileron control signal input as the control signal and a second aileron control signal calculated for maintaining the horizontal position of the controlled object based on the roll angle of the controlled object, wherein the calculation unit is instructed to turn on by a function setting signal received from an external source, the first aileron control signal is a signal indicating neutral, and the roll angle of the controlled object is within a set angle, and the calculation unit selects and outputs the second aileron control signal when these conditions are met. In other words, the new flight assistance function will be activated not only when the function is instructed to be turned on, but also when the conditions are met that the first aileron control signal is neutral and the roll angle is within a set angle. This function uses aileron control signals calculated based on the roll angle to maintain the aircraft's horizontal position. Maintaining horizontal position means maintaining the roll angle at approximately 0° or approximately 180°. Furthermore, the attitude control device according to the present invention may also include an additional condition for activating a new function: that the pitch angle of the controlled body is within a set angle. [Effects of the Invention]

[0009] According to the present invention, when controlling a piloted vehicle, even when the flight assistance function is activated, it is possible to properly perform maneuvers such as turning and landing. [Brief explanation of the drawing]

[0010] [Figure 1] This figure shows an example of the configuration of a control system according to an embodiment of the present invention. [Figure 2] This is a block diagram showing an example of the internal configuration of the transmitter and the controlled body according to the embodiment. [Figure 3] This is a block diagram of an example configuration of the attitude control device according to the first embodiment. [Figure 4] This is an explanatory diagram of the pulse width of the function setting signal in the embodiment. [Figure 5] This is an explanatory diagram of the pulse width of the aileron control signal in the embodiment. [Figure 6] This is a flowchart of the aileron control signal selection process in the first embodiment. [Figure 7] This is a block diagram of an example configuration of the attitude control device according to the second embodiment. [Figure 8] This is a flowchart of the aileron control signal selection process in the second embodiment. [Figure 9] This is a block diagram of an example configuration of the attitude control device according to the third embodiment.

Mode for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present invention will be described in the following order. <1. First Embodiment> [1-1 Example of System Configuration] [1-2 Example of Configuration of Transmitter and Controlled Object] [1-3 Configuration and Processing of Attitude Control Device] <2. Second Embodiment> <3. Third Embodiment> <4. Effects of Embodiments>

[0012] <1. First Embodiment> [1-1 Example of System Configuration] FIG. 1 shows an example of the configuration of a control system 1 according to an embodiment of the present invention. In the following embodiments, a new flight assistance function will be referred to as the "roll flat function". The roll flat function is also a function for automatically maintaining the aircraft in a horizontal state, but it is different from the above-mentioned "automatic return to horizontal flight function", so it is to distinguish it from the automatic return to horizontal flight function.

[0013] The control system 1 is configured to include at least a controlled object 2 and a transmitter 3. The controlled object 2 is an object that is controlled based on a control signal received from the outside. The transmitter 3 is a device that transmits various signals including a control signal to the controlled object 2.

[0014] In this embodiment, a model airplane is cited as an example of the controlled object 2. The controlled object 2 as a model airplane includes a fuselage portion 21, a pair of left and right main wings 22, 22 and horizontal tail wings 23, 23, and a vertical tail wing 24.

[0015] Here, the attitude of the controlled vehicle 2 can be expressed by the direction of rotation around the roll axis, the direction of rotation around the pitch axis, and the direction of rotation around the yaw axis. In the figure, these directions of the roll axis, pitch axis, and yaw axis are illustrated as examples, but as shown in the figure, the roll axis is the axis that runs through the fuselage 21 of the controlled vehicle 2 from front to back, the pitch axis is the axis that runs through the controlled vehicle 2 from left to right, and the yaw axis is the axis that runs through the controlled vehicle 2 from up to down.

[0016] In the piloted vehicle 2, each main wing 22 is equipped with an aileron 26. In addition, each horizontal stabilizer 23 is equipped with an elevator 27, and the vertical stabilizer 24 is equipped with a rudder 28. The aileron 26 is a movable wing section for rotating the controlled object 2 around the roll axis. The elevator 27 is a movable wing section for rotating the controlled object 2 around the pitch axis, and the rudder 28 is a movable wing section for rotating the controlled object 2 around the yaw axis. By operating these ailerons 26, elevator 27, and rudder 28, the flight attitude of the piloted vehicle 2 can be changed.

[0017] Furthermore, the piloted vehicle 2 is equipped with a propeller 25. The rotation of this propeller 25 can provide thrust to the piloted vehicle 2 in the forward and backward directions. The piloted vehicle 2 is configured to allow the rotation direction of the propeller 25 to be switched. Switching the rotation direction of the propeller 25 makes it possible to switch the piloted vehicle 2 between moving forward and backward.

[0018] Transmitter 3 has the function of receiving control commands from the user as the pilot and transmitting control signals corresponding to the received commands. The transmitter 3 includes an antenna 3a for wirelessly transmitting control signals, an operator 3b for receiving control inputs for operation, and a display screen 33a for displaying various information to the user, such as the pilot. Here, a transmitter 3 is shown as an example of a type equipped with two stick-shaped controls 3b for control, but the shape of the controls 3b is not limited to sticks; other shapes such as wheel shapes are also possible, and the number of controls 3b can also be other than two.

[0019] Hereinafter, in this specification, "control signal" means a signal that instructs the operation of a movable part of the controlled body 2, such as a propeller 25, aileron 26, elevator 27, rudder 28, etc. In the control system 1, signals other than control signals that instruct the movement of movable parts can also be transmitted from the transmitter 3 to the controlled body 2. For example, a function setting signal that instructs the on / off of the roll-flat function is transmitted from the transmitter 3 to the controlled body 2.

[0020] In the control system 1, multiple channels are available for transmitting signals from the transmitter 3 to the controlled object 2. For example, the control system 1 provides a total of 18 channels for signal transmission. Using these multiple channels, it is possible to transmit control signals for each movable part, such as the propeller 25, aileron 26, elevator 27, and rudder 28, separately for each channel. Specifically, it is possible to set which signal is transmitted for each channel, for example, by assigning the control signal for the propeller 25 to channel CH1, the control signal for the aileron 26 to channel CH2, and the control signal for the elevator 27 to channel CH3. In this type of channel-specific transmission signal assignment setting, it is also possible to assign signals other than control signals as transmission signals. For example, a function setting signal could be assigned to channel CH5.

[0021] [1-2 Example of transmitter and controlled device configuration] Referring to the block diagram in Figure 2, an example of the internal configuration of the transmitter 3 and the controlled body 2 will be described. Figure 2 shows an example of the electrical configuration of the transmitter 3 and the controlled body 2, while the mechanical configuration is not shown.

[0022] As shown in the figure, the transmitter 3 comprises a transmitter-side control unit 31, an operation unit 32, a display unit 33, and a transmission unit 34. The control unit 32 comprehensively represents the controls that the user uses to input various operations to the transmitter 3. Specifically, it comprehensively represents the controls 3b for control operations such as the stick described above, as well as controls such as buttons, keys, levers, and touch panels for various operations other than control operations. In the transmitter 3 of this example, a touch panel for detecting touch operations on the display screen 33a is formed on the display screen 33a described above, and the touch panel is also included as an operator in the operation unit 32.

[0023] The display unit 33 is configured with a display device such as an LCD (Liquid Crystal Display) or an organic EL (Electro Luminescence) display, and displays various information to the user. The display screen 33a described above is the display screen of the display unit 33.

[0024] The transmitter-side control unit 31 is configured with a microcomputer equipped with, for example, a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), etc., and the CPU performs overall control of the transmitter 3 by executing processing according to a program stored in memory such as ROM. For example, the transmitter-side control unit 31 performs a process to generate a control signal based on the operation of the operator 3b in the operation unit 32. Furthermore, the transmitter-side control unit 31 processes various information to be displayed on the display unit 33 based on operations on predetermined operators other than the operator 3b on the operation unit 32, particularly on the touch panel on the display screen 33a described above in this example. For example, it processes the display unit 33 to display the settings menu screen, or to display the settings screen for the item selected from the settings menu screen. In addition, on the settings screen, it processes the display of information such as values ​​instructed by the user through operations on the operation unit 32, and processes setting operations corresponding to the instruction operations for settings.

[0025] Furthermore, the transmitter-side control unit 31 performs a process to cause the transmission unit 34 to transmit signals to the controlled body 2, such as the generated control signals. The transmitting unit 34 transmits the signal instructed by the transmitter-side control unit 31 via the antenna 3a.

[0026] The transmitting unit 34 may have a receiving function as well as a transmitting function. If the receiver 4, which will be described later, has a transmitting function, the transmitter 3 can receive information acquired on the controlled body 2 side. For example, if the controlled body 2 is equipped with monitoring sensors such as a temperature sensor or a rotation speed sensor for the propeller 25 (propulsion motor 7, which will be described later), the transmitter 3 can receive the detection information from these sensors and display it on the display unit 33.

[0027] The controlled vehicle 2 is equipped with a receiver 4, an attitude control device 5, an ESC (Electronic Speed ​​Controller, also called a speed controller) 6, a propulsion motor 7, and a plurality of servo motors 8 (8R, 8E, 8A).

[0028] The propulsion motor 7 is a motor that rotates the propeller 25 shown in Figure 1. For example, the propulsion motor 7 is a motor that can switch the direction of rotation by the polarity of the drive current.

[0029] Three servo motors 8 are provided: servo motor 8A for driving the aileron 26, servo motor 8E for driving the elevator 27, and servo motor 8R for driving the rudder 28.

[0030] The receiver 4 has an antenna 4a and receives signals transmitted by the transmitting unit 34 of the transmitter 3. Receiver 4 outputs the received signal to ESC 6 and attitude control device 5.

[0031] The ESC6 acquires control signals that instruct the operation of the propeller 25, which are included in the transmission signal from the transmitter 3 input via the receiver 4, and generates a drive signal for the propulsion motor 6 based on these control signals. This drive signal is output to the propulsion motor 7, and the propulsion motor 7 is driven.

[0032] As described later, the attitude control device 5 has sensors (3-axis angular velocity acceleration sensors 11) corresponding to the roll axis, pitch axis, and yaw axis, and is a unit that controls the attitude of the controlled body 2 based on the detection signals, i.e., the angular velocity and acceleration signals of each axis.

[0033] As will be described in more detail later, the attitude control device 5 extracts the aileron control signal that instructs the operation of the aileron 26, the elevator control signal that instructs the operation of the elevator 27, and the rudder control signal that instructs the operation of the rudder 28 from the transmission signal from the transmitter 3 input via the receiver 4. Based on these control signals and the sensor detection signals, it generates drive signals AL2, EL2, and RD2 for the servo motors 8A, 8E, and 8R, respectively, to realize attitude control (attitude stabilization control). In this way, the servo motors 8A, 8E, and 8R are driven based on the drive signals AL2, EL2, and RD2 generated by the attitude control device 5, thereby achieving attitude stabilization control of the controlled body 2.

[0034] [1-3 Configuration and Processing of Attitude Control Devices] Figure 3 shows an example configuration of the attitude control device 5. Figure 3 shows a configuration that can switch between outputting drive signals AL2, EL2, and RD2 to servo motors 8A, 8E, and 8R corresponding to the aileron control signal AL1, elevator control signal EL1, and rudder control signal RD1 transmitted from transmitter 3 (i.e., no flight assistance is provided) and outputting drive signals due to the roll-flat function to servo motors 8A, 8E, and 8R (i.e., the flight assistance function is activated).

[0035] Figure 3 shows an example configuration for realizing the roll-flat function, but does not show the automatic horizontal flight return function. It is possible to have both the automatic horizontal flight return function and the roll-flat function coexist in the attitude control device 5, allowing the user to arbitrarily select which one to activate, but this will be explained in the third embodiment, and the first embodiment will focus on explaining the roll-flat function.

[0036] Furthermore, the attitude control device 5 may include functions and circuit blocks other than those shown, or some of the functions and circuit blocks shown may be omitted. Figure 3 also shows an example configuration of the attitude control device 5, along with the receiver 4 shown in Figure 2.

[0037] The attitude control device 5 includes a communication unit 10, a 3-axis angular velocity acceleration sensor 11 (hereinafter referred to as "sensor 11"), a roll-flat calculation unit 12, and drive signal generation units 15, 16, and 17.

[0038] The communication unit 10 receives signals from the transmitter 3 that are received by the receiver 4. Although not described in detail here, the attitude control device 5 can also transmit information to an external device via the communication unit 10.

[0039] Sensor 11 is a sensor that detects angular velocity Rag and acceleration Rac around the roll axis (direction of rotation by the aileron 26), angular velocity Pag and acceleration Pac around the pitch axis (direction of rotation by the elevator 27), and angular velocity Yag and acceleration Yac around the yaw axis (direction of rotation by the rudder 28).

[0040] The roll-flat calculation unit 12 is capable of wired communication with an external device via the communication unit 10. When the controlled body 2 is being controlled, as shown in the figure, the receiver 4 is wired to the communication unit 10, and the roll-flat calculation unit 12 is capable of receiving the transmission signal from the transmitter 3 that the receiver 4 receives via the communication unit 10.

[0041] Specifically, the roll-flat calculation unit 12 receives the rudder control signal RD1, elevator control signal EL1, aileron control signal AL1, and function setting signal RFF as transmission signals from the transmitter 3. When the roll-flat calculation unit 12 does not activate the roll-flat function, it supplies the rudder control signal RD1, the elevator control signal EL1, and the aileron control signal AL1 to the drive signal generation units 15, 16, and 17, respectively.

[0042] The drive signal generation unit 15 generates a drive signal RD2 for the servo motor 8R based on the rudder control signal RD1. The drive signal generation unit 16 generates a drive signal EL2 for the servo motor 8E based on the elevator operation signal EL1. The drive signal generation unit 17 generates a drive signal AL2 for the servo motor 8A based on the aileron control signal AL1.

[0043] These drive signals RD2, EL2, and AL2 are supplied to the servo motors 8R, 8E, and 8A, allowing the attitude of the controlled object 2 to be controlled according to the operator's input using the transmitter 3.

[0044] When the roll-flat function of this embodiment is activated, the rudder control signal RD1 is supplied to the drive signal generation unit 15, and the elevator control signal EL1 is supplied to the drive signal generation unit 16. In other words, the rudder and elevator operations performed by the operator are directly reflected in the rudder 28 and elevator 27. On the other hand, the aileron control signal ALa is supplied to the drive signal generation unit 17. The aileron control signal ALa is a control signal that is automatically generated for horizontal return based on the detection signal from the sensor 11.

[0045] In other words, when the roll-flat function is not activated, the aileron control signal AL1 is selected and supplied to the drive signal generation unit 17, while the roll-flat function is activated when the aileron control signal ALa is supplied to the drive signal generation unit 17.

[0046] The functional configuration of the roll-flat calculation unit 12 for this purpose will now be explained. In particular, the roll-flat function in this embodiment does not activate or continue simply by the instruction to turn on the roll-flat function. Rather, it is activated and continues only when the following conditions are met: the instruction to turn on the roll-flat function is received from the transmitter 3, the aileron control signal AL1 is a neutral signal, and the roll angle of the controlled body 2 is within the set angle. Here, activation and continuation of the roll-flat function refers to the state in which the aileron control signal ALa is supplied to the drive signal generation unit 17. Figure 3 shows the configuration of the roll-flat calculation unit 12 that controls the activation / deactivation of the roll-flat function under these conditions.

[0047] The roll-flat calculation unit 12 can be implemented as a calculation device using a microprocessor or as a calculation device using hardware logic circuits. The roll-flat calculation unit 12 is provided with the following functions, which are either software-based or hardware-based: a pulse determination unit 50, an attitude angle calculation unit 51, an on / off determination unit 52, a selection unit 54, a neutral determination unit 55, an aileron operation amount calculation unit 56, and a roll angle confirmation unit 57.

[0048] The pulse determination unit 50 receives the function setting signal RFF from the transmitter 3 via the communication unit 10 and determines the pulse width of the ON side of the function setting signal RFF. The transmitter 3 transmits the user's operation of turning the roll flat function on / off, as well as information on the pre-set roll angle, via the function setting signal RFF. In this case, the roll angle information is the information on the set angle, which is one of the conditions for activating the roll flat function described above.

[0049] Figure 4 shows the function setting signal RFF. The function setting signal RFF is defined as a signal that generates an H-level pulse with a period of, for example, 15 msec and a duration of, for example, 1500 μsec ± 600 μsec. The diagram illustrates the cases where the H level period is 1500 μsec, 1800 μsec, 2000 μsec, 2100 μsec, and 1100 μsec. These pulse widths are determined according to the user's settings on the transmitter 3.

[0050] These pulse widths provide information indicating the function on / off instruction and the set roll angle, i.e., the roll angle as the condition for function activation. For example, if the function setting signal RFF is a signal with a high-level period of 1500 μsec ± 600 μsec, then when the high-level period is between 1500 μsec and 2100 μsec, it indicates that the roll-flat function is ON. On the other hand, when the H level period is from 1499 μsec to 900 μsec, it indicates that the roll-flat function is off. For example, in the case of 1100 μsec as shown in the figure, it is a signal indicating that the roll-flat function is off.

[0051] The H-level pulses from 1500 μsec to 2100 μsec, which indicate the roll-flat function is on, are defined by their pulse width (duration), which represents the roll angle. For example, 1500 μsec is defined as 0°, and the angle increases by 1° every 10 μsec. Therefore, as shown in the figure, 1800 μsec corresponds to 30°, 2000 μsec to 50°, and 2100 μsec to 60°. For example, in this case, the user can arbitrarily set the angle between 0° and 60° as the condition for activating the roll-flat function.

[0052] Setting the angle to 0° means that the roll angle is within 0° or within 180° in inverted flight, in other words, the roll flat function will only be activated when the aircraft is level in forward or inverted flight. A setting angle of 30° means that the roll angle is within 0°±30° or within 180°±30° in inverted flight, in other words, the roll flat function is activated when the roll angle is within ±30° of horizontal in either forward or inverted flight.

[0053] The pulse determination unit 50 determines the pulse width of the H level in the function setting signal RFF as described above, and notifies the on / off determination unit 52 and the roll angle confirmation unit 57 of the pulse width. The on / off determination unit 52 determines that the roll flat function is instructed to be turned on if the notified pulse width is 1500 μsec or more. The on / off determination unit 52 then notifies the selection unit 54 of the determination result of whether the roll flat function is on or off.

[0054] The roll angle confirmation unit 57 determines the set angle as a condition for the roll angle based on whether the pulse width notified by the pulse determination unit 50 is between 1500 μsec and 2100 μsec. For example, if the pulse width is 1800 μsec, the set angle is set to ±30°.

[0055] The aileron control signal AL1, input via the communication unit 10, is supplied to the neutral determination unit 55 and the selection unit 54 (terminal m in the figure). The neutral determination unit 55 determines whether the aileron control signal AL1 is neutral or not.

[0056] Figure 5 shows an example of the aileron control signal AL1. For example, the aileron control signal AL1, like the function setting signal RFF, is a signal that generates an H-level pulse with a period of 15 msec. When the H-level pulse is 1500 μsec, it is neutral; when it exceeds 1500 μsec, it instructs the servo motor 8 to rotate to the right; and when it is less than 1500 μsec, it instructs the servo motor 8 to rotate to the left.

[0057] Figure 5 shows the cases where the H level period is 1500 μsec, 1500 + T1 μsec, and 1500 - T2 μsec, respectively. If the H level period is 1500 μsec, it is neutral. If the H level period is 1500 + T1 μsec, it becomes a signal that instructs a clockwise rotation by the amount indicated by period T1. If the H level period is 1500-T2μsec, it will be a signal that indicates a leftward rotation by the amount indicated by period T2.

[0058] In such an example, the neutral determination unit 55 notifies the selection unit 54 of whether or not the H level period is 1500 μsec, that is, whether it is neutral or whether aileron drive is instructed.

[0059] The attitude angle calculation unit 51 calculates the attitude angles of the controlled body 2 based on the detection signals from the sensor 11. For example, it calculates the roll angle Ra, pitch angle Pa, and yaw angle Ya. The roll angle Ra information obtained by the attitude angle calculation unit 51 is supplied to the aileron operation amount calculation unit 56 and the roll angle confirmation unit 57.

[0060] The roll angle confirmation unit 57 compares the roll angle indicated by the function setting signal RFF with the current roll angle Ra to determine whether the current roll angle Ra is within the set roll angle. The result of this determination is then notified to the selection unit 54.

[0061] The aileron control amount calculation unit 56 calculates an aileron control signal ALa to return the aircraft attitude of the controlled vehicle 2 to horizontal, i.e., to a roll angle of 0° (or 180°), based on the current roll angle Ra. This aileron control signal ALa is supplied to the selection unit 54 (terminal a in the figure).

[0062] The selection unit 54 is shown as a switch having an m terminal and an a terminal, but this is a schematic representation. It may be formed as an actual selection circuit, but it is sufficient if it has the function of selecting and outputting either the aileron control signal AL1 or the aileron control signal ALa through calculation.

[0063] The selection unit 54 performs the selection process, for example, as shown in Figure 6. The selection unit 54 determines whether or not the roll-flat function is instructed to be turned on in step S101. That is, it determines this based on the notification from the on / off determination unit 52. In step S102, the selection unit 54 determines whether the aileron control signal AL1 is neutral or not based on the notification from the neutral determination unit 55. In step S103, the selection unit 54 determines whether the current roll angle Ra is within the set roll angle based on a notification from the roll angle confirmation unit 57.

[0064] If positive results are obtained in all of steps S101, S102, and S103, the selection unit 54 proceeds to step S110, where it selects terminal a, i.e., the aileron control signal ALa, and supplies it to the drive signal generation unit 17. If any one of steps S101, S102, or S103 yields a negative result, the selection unit 54 proceeds to step S111, selects the m terminal, i.e., the aileron control signal AL1, and supplies it to the drive signal generation unit 17.

[0065] Due to the functions of the roll-flat calculation unit 12 as described above, when the function setting signal RFF from the transmitter 3 instructs the roll-flat function to be ON, the aileron control signal AL1 is a neutral signal, and the roll angle Ra of the controlled vehicle 2 is within the set angle, the aileron control signal ALa is supplied to the drive signal generation unit 17, and flight assistance by the roll-flat function is activated. At this time, the rudder control signal RD1 and elevator control signal EL1 are supplied directly to the drive signal generation units 15 and 16, so that user rudder and elevator operations remain active and unrestricted even while the roll-flat function is activated.

[0066] After the roll-flat function is activated, automatic level-keeping control by aileron control signal ALa continues until the conditions are no longer met, for example, until aileron control signal AL1 becomes anything other than neutral. However, when the user operates the ailerons, the aileron control signal AL1 becomes something other than neutral. Consequently, the aileron control signal AL1 is selected by the selection unit 54, and the roll-flat function is deactivated.

[0067] These factors lead to the following advantages: In the case of the aforementioned automatic level flight return function, if you attempt to turn while automatic control is active, the aileron input is restricted, preventing you from turning to the desired angle and resulting in a wide turn. Also, when landing, it is necessary to input the elevator to raise the nose, but the elevator is automatically operated to return to a level attitude, causing the nose to drop.

[0068] In contrast, with the roll-flat function of this embodiment, even when performing a turning maneuver for landing approach while the roll-flat function is activated, both aileron and elevator operations can be performed as usual, and the turning can be performed in accordance with the operation, resulting in a natural feel and making operational errors less likely. Furthermore, in landing approach (on the extension of the runway with a horizontal roll angle), the roll angle is automatically maintained horizontally, allowing the pilot to concentrate on controlling aircraft speed and altitude, i.e., operating the throttle and elevator. Furthermore, the elevator operates as usual, so you can use it without any problems. Furthermore, the roll-flat function allows for stable horizontal flight when flying directly in front of or behind the aircraft.

[0069] Furthermore, the roll angle at which the roll-flat function is activated can be set from transmitter 3. For example, beginners can set a larger roll angle to activate the roll-flat function earlier, allowing the function to automatically maintain a level flight. On the other hand, advanced pilots can activate the roll-flat function after the aircraft has almost reached a level flight. In other words, the roll-flat function can be used according to the pilot's skill level and preferences.

[0070] <2. Second Embodiment> Figure 7 shows an example configuration of the attitude control device 5 according to the second embodiment. Note that the same parts as in Figure 3 are denoted by the same reference numerals to avoid redundant explanation. In Figure 7, the pitch angle confirmation unit 58 is provided, which is a difference from the first embodiment.

[0071] The pitch angle confirmation unit 58 obtains the current pitch angle Pa of the aircraft calculated by the attitude angle calculation unit 51 and determines whether it is less than or equal to a preset angle. For example, a pitch angle of 60° may be set in advance as the preset angle.

[0072] In this case, the pitch angle setting (e.g., 60°) should be set to an angle that results in a steep descent or ascent. In the case of a steep ascent or descent, it is difficult to determine whether the plane is horizontal to the ground, and there is no particular need to be concerned with maintaining a horizontal position. In particular, the roll-flat function is not very useful. Therefore, the roll-flat function will be disabled if the pitch angle Pa exceeds the set angle.

[0073] Therefore, the pitch angle confirmation unit 58 notifies the selection unit 54 of the information it has determined regarding whether the pitch angle Pa is less than or equal to the set angle. The selection unit 54 performs the selection process as shown in Figure 8. Note that the same steps as in Figure 6 are assigned the same step numbers to avoid detailed explanations.

[0074] In steps S101, S102, and S103, the selection unit 54 determines whether the roll flat function is instructed to be ON, whether the aileron control signal AL1 is neutral, and whether the current roll angle Ra is within the set roll angle. In addition, in step S104, the selection unit 54 determines whether the current pitch angle Pa is within the set pitch angle based on a notification from the pitch angle confirmation unit 58.

[0075] If positive results are obtained in all of steps S101, S102, S103, and S104, the selection unit 54 proceeds to step S110, selects the aileron control signal ALa, and supplies it to the drive signal generation unit 17. If any one of steps S101, S102, S103, or S104 yields a negative result, the selection unit 54 proceeds to step S111, selects the aileron control signal AL1, and supplies it to the drive signal generation unit 17.

[0076] In this second embodiment, as in the first embodiment, user operation remains effective even when the roll-flat function is activated, and in addition, the roll-flat function is deactivated during rapid ascent and descent. The pitch angle setting can also be changed by the user via operation from transmitter 3.

[0077] <3. Third Embodiment> Figure 9 shows an example of the configuration of the attitude control device 5 according to the third embodiment. Note that the same parts as in Figure 7 are denoted by the same reference numerals to avoid redundant explanation. Figure 9 shows an example where the roll-flat function and the automatic horizontal flight return function coexist, and the function selection is performed using a function setting signal RFF from a single signal transmission channel from the transmitter 3. For this reason, the part corresponding to the roll-flat calculation unit 12 in Figure 7 is shown as the flight assistance function calculation unit 12A.

[0078] The automatic horizontal flight return function, when enabled, outputs an aileron control signal ALa calculated based on the roll angle Ra of the piloted vehicle 2 to maintain horizontal flight, and an elevator control signal ELa calculated based on the pitch angle Pa of the piloted vehicle 2 to maintain horizontal flight. Therefore, in Figure 9, in addition to the configuration in Figure 7, an elevator operation amount calculation unit 60 and a selection unit 61 are provided.

[0079] The elevator operation amount calculation unit 60 calculates the elevator operation amount for horizontal return based on the current pitch angle Pa calculated by the attitude angle calculation unit 51, and outputs an elevator operation signal ELa. This elevator operation signal ELa is supplied to the selection unit 61 (terminal a in the figure).

[0080] The selection unit 61 is shown as a switch having an m terminal and an a terminal, but this is a schematic representation. It may be formed as an actual selection circuit, but it is sufficient if it has the function of selecting and outputting either the elevator control signal EL1 or the elevator control signal ELa through calculation.

[0081] The on / off determination unit 52 determines whether the function is off, the roll-flat function is on, or the automatic horizontal flight return function is on based on the pulse width of the function setting signal RFF. The on / off determination unit 52 then notifies the selection units 54 and 61 of the determination result. For example, as explained in Figure 4, the roll flat function is determined to be ON when the H-level pulse width is 1500 μsec or more, and the set angle for the roll angle condition is also determined. In this case, for example, the roll flat function is ON from 1500 μsec to less than 2100 μsec, and the duration of that H-level period indicates the roll angle. Furthermore, if the duration of the H level period is the maximum value of 2100 μsec, it is determined that the automatic horizontal flight return function is turned on. In other words, the pulse width is used to determine whether to turn on the roll-flat function or the automatic horizontal flight return function.

[0082] The selection process for selection units 54 and 61 is as follows. If the pulse width of the function setting signal RFF is less than 1500 μsec and the flight assistance function is off, both selection units 54 and 61 select the m terminal. Consequently, the aileron control signal AL1 and the elevator control signal EL1 are supplied to the drive signal generation units 16 and 17.

[0083] If the pulse width of the function setting signal RFF is between 1500 μsec and less than 2100 μsec, the selection unit 54 assumes that the roll-flat function is ON and selects either the aileron control signal AL1 or the aileron control signal ALa in the processing example shown in Figure 8. On the other hand, the selection unit 61 always selects the elevator control signal EL1 (m terminal). In other words, the selection is made by the roll-flat function as described above.

[0084] If the pulse width of the function setting signal RFF is 2100 μsec, both selection units 54 and 61 select terminal a. Consequently, the aileron control signal ALa and the elevator control signal ELa are supplied to the drive signal generation units 16 and 17. This activates the automatic return to level flight function.

[0085] In both the roll-flat function and the automatic return-to-level-flight function, the rudder control signal RD1 is supplied directly to the drive signal generation unit 15. In practice, even when the automatic level flight return function is turned on, aileron and elevator operations are not impossible, although they are limited. Therefore, the aileron operation amount calculation unit 56 in Figure 9 calculates the aileron control signal ALa by referring to the aileron control signal AL1 in addition to the roll angle Ra. Similarly, the elevator operation amount calculation unit 60 calculates the elevator control signal ELa by referring to the elevator control signal EL1 in addition to the pitch angle Pa.

[0086] As shown in Figure 9, both the roll-flat function and the automatic horizontal flight return function can be selectively activated. Furthermore, both the roll-flat function and the automatic horizontal flight return function can be controlled by a single signal transmission channel from transmitter 3. Furthermore, separate signal transmission channels may be used for controlling the roll-flat function and the automatic horizontal flight return function. In that case, if both channels are instructed to turn on the function, the attitude control device 5 should interpret the instruction to turn on one of the functions as the priority.

[0087] Furthermore, in the third embodiment, the activation conditions for the roll-flat function were described in addition to the pitch angle conditions described in the second embodiment, but the activation determination of the roll-flat function may also be made using the conditions shown in Figure 6, as described in the first embodiment.

[0088] <4. Effects of the Embodiment> According to the above embodiments, the following effects can be obtained.

[0089] The attitude control device 5 of the first embodiment includes a roll-flat calculation unit 12 that selectively outputs a first aileron control signal AL1 input as a control signal and a second aileron control signal ALa calculated for maintaining the horizontal position of the controlled body 2 based on the roll angle Ra of the controlled body 2. The roll-flat calculation unit 12 selects and outputs the second aileron control signal ALa when the roll-flat function is instructed to be ON by the function setting signal RFF, the first aileron control signal AL1 is a signal indicating neutral, and the roll angle Ra of the controlled body 2 is within the set angle. By introducing this roll-flat function, automatic aileron control is performed only when the roll angle of the controlled aircraft 2 is within a predetermined angle from the horizontal position, without any user aileron operation, in addition to the roll-flat function being turned on. This means that the automatic level-keeping control by the roll-flat function is performed when it does not affect the user's control, resulting in improved maneuverability and control that is tailored to the pilot's skill level.

[0090] In the second embodiment, the attitude control device 5 has a roll-flat calculation unit 12 that selects and outputs a second aileron control signal ALa when the following conditions are met: the roll-flat function is instructed to be ON by the function setting signal RFF, the first aileron control signal AL1 is a signal indicating neutral, the roll angle Ra of the controlled body 2 is within the set angle, and the pitch angle Pa of the controlled body 2 is within the set angle. In other words, the condition for the roll-flat function to manifest is further enhanced by the requirement that the pitch angle Pa is within a set angle. By also considering the pitch angle, it's possible to prevent the roll-flat function from activating when it's not meaningful, such as during steep descents or ascents. In other words, the roll-flat function will be activated when horizontal stability control is more useful.

[0091] In the first, second, and third embodiments, the roll-flat calculation unit 12 selects and outputs the first aileron control signal AL1 when the conditions are not met. Therefore, even if the aileron control signal ALa is output from the selection unit 54 due to the roll-flat function, if the aileron control signal AL1 from the control signal is not neutral, the aileron control signal AL1 will be output immediately from the selection unit 54. In other words, even when the roll-flat function is activated, if an aileron operation is performed, that aileron operation will be accepted. This allows for smooth turning operations and reduces the likelihood of operating errors.

[0092] In the first, second, and third embodiments, the roll-flat calculation unit 12 selects and outputs the second aileron control signal ALa when the conditions are met, and during this period, it outputs the elevator control signal EL1, which is input as a control signal from the transmitter 3, for elevator control. Even with the roll-flat function in control, the elevator remains in normal operation, allowing for seamless operation. Especially during landing, you can leave the roll angle to automatic control while concentrating on elevator and throttle control.

[0093] In the first, second, and third embodiments, the roll flat calculation unit 12 sets the angle that is the condition for the roll angle of the controlled body 2 based on the pulse width of the function setting signal RFF. This allows the angle range in which the roll angle is automatically controlled to be set from the transmitter 3, so the angle range in which automatic control is initiated can be changed according to the pilot's skill level. For example, a beginner can use it to automatically control the aircraft to be horizontal even from an angle that is somewhat off-horizon, while an advanced pilot can use it to automatically control the aircraft only from a nearly horizontal attitude. Furthermore, by allowing the set angle, which is the condition for the roll angle, to be specified by the pulse width, the roll-flat function can be turned on / off and the angle set using a single channel from transmitter 3, thereby improving the efficiency of transmitted information. Note that the 1500 μsec to 2100 μsec range mentioned above is merely an example for illustrative purposes. The specific numerical value for the pulse width is not particularly limited.

[0094] In the third embodiment, the roll-flat calculation unit 12 outputs an aileron control signal ALa and an elevator control signal ELa when the pulse width of the function setting signal RFF is a predetermined value, for example, the maximum value. In other words, the automatic return to level flight function is turned on. This allows the roll-flat function and the automatic horizontal flight return function to be controlled by a single channel's function setting signal RFF, making the information transmitted from transmitter 3 more efficient. While the example uses the maximum pulse width (e.g., 2100 μsec), 2100 μsec is just one example. Furthermore, while the maximum value is used as an example, it doesn't have to be the maximum; any pulse width that specifies the automatic horizontal flight return function being ON would suffice. [Explanation of Symbols]

[0095] 2 Maneuvered object 3 Transmitter 4 Receiver 5. Attitude control system 8, 8R, 8E, 8A Servo Motors 10 Communications Department 11 sensors 12 Roll Flat Calculation Unit 15, 16, 17 Drive signal generation unit 26 Ailerons 27 Elevator 28 Ladder 50 Pulse determination unit 51 Attitude angle calculation section 52 On / Off Determination Unit 54 Selection Section 55 Neutral Determination Unit 56 Aileron control amount calculation unit 57 Roll angle confirmation section 58 Pitch angle confirmation section 60 Elevator operation amount calculation unit 61 Selection Section

Claims

1. An attitude control device installed in a radio-controlled model airplane, which is a controlled object whose operation is performed based on control signals received from an external device, The system includes a calculation unit that selectively outputs a first aileron control signal input as the control signal and a second aileron control signal calculated based on the roll angle of the controlled body to maintain the controlled body horizontally. The aforementioned arithmetic unit, When the function is turned ON by a function setting signal received from an external source, the first aileron control signal is a neutral signal, and the roll angle of the controlled object is within the set angle, the second aileron control signal is selected and output. Posture control device.

2. An attitude control device installed in a radio-controlled model airplane, which is a controlled object whose operation is performed based on control signals received from an external device, The system includes a calculation unit that selectively outputs a first aileron control signal input as the control signal and a second aileron control signal calculated based on the roll angle of the controlled body to maintain the controlled body horizontally. The aforementioned arithmetic unit, The function is turned ON by a function setting signal received from an external source, the first aileron control signal is a neutral signal, the roll angle of the controlled vehicle is within the set angle, and the pitch angle of the controlled vehicle is within the set angle. When these conditions are met, the second aileron control signal is selected and output. Posture control device.

3. The aforementioned arithmetic unit, Except when the above conditions are met, the first aileron control signal is selected and output. The posture control device according to claim 1 or claim 2.

4. The aforementioned arithmetic unit, During the period when the second aileron control signal is selected and output due to the fulfillment of the above conditions, the elevator control signal input as the control signal is output with respect to elevator control. The posture control device according to claim 1 or claim 2.

5. The aforementioned arithmetic unit, The set angle that is the condition for the roll angle of the controlled object is an angle set based on the pulse width of the function setting signal. The posture control device according to claim 1 or claim 2.

6. The aforementioned arithmetic unit, When the pulse width of the function setting signal is a predetermined value, Aileron control signals calculated to maintain the horizontal position of the piloted body based on the roll angle of the piloted body, An elevator control signal calculated to maintain the horizontal position of the controlled object based on the pitch angle of the controlled object, Output The attitude control device according to claim 5.

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