JPS6021748B2 - Tail rotor pitch angle control device for radio-controlled helicopters - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tail rotor pitch angle control device for a radio controlled helicopter.

A radio control helicopter rotates its main rotor to obtain lift, and as the main rotor rotates, reaction torque is generated in the aircraft body, so the tail rotor is rotated to cancel out the reaction torque. In addition, as the rotational speed of the main rotor changes, the reaction torque also increases or decreases, so the pitch angle of the tail rotor is changed in conjunction with this, and the thrust of the tail rotor is also changed, so that the reaction torque is always canceled out by the tail rotor thrust. You must ensure that the Therefore, when the rotational speed of a helicopter's main rotor is artificially changed by remote control from the ground, it is necessary to simultaneously send a signal to the aircraft to correct the pitch angle of the tail rotor, and various control methods have been proposed for this purpose. It has reached this point. However, according to these control methods, there is no problem if the main rotor's rotational speed is changed by remote control from the ground, but the natural If the force is due to an external force such as wind, the pitch angle of the tail rotor will not change, and the aircraft will rotate due to reaction torque. For example, if a helicopter that is stationary in the air starts moving forward, even if it is assumed that there is no wind, this forward movement causes wind (air) to flow from above the main rotor to below, increasing lift. This is called transfer cooperation, and due to the transfer lift generated by this forward movement, the rotation of the main rotor becomes lighter compared to when it is stationary in the air, the rotation speed of the main rotor increases, and the recoil torque of the aircraft increases. . Other external forces, such as wind blowing against the helicopter, also change the engine output, which changes the load on the main rotor, which in turn causes the main rotor rotational speed to increase or decrease from the set rotational speed, causing the aircraft to rotate. It is impossible for an operator on the ground to cope with such subtle and unpredictable natural forces that are applied to the helicopter using the above-mentioned control method. For this reason, it is required that the pitch angle of the tail row be automatically corrected independently on the helicopter side and independently of remote control from the ground side by changing the rotational speed of the main rotor. The present invention satisfies this need. The following will be explained based on the drawings. Fig. 1 is a block diagram of the main rotor rotational speed automatic control circuit in the receiver on the aircraft side, and a plurality of magnets 2 are equipped on the shaft 1 of the main rotor at regular intervals in the circumferential direction. The number of rotations of the shaft 1 is read out by a sensor 3 via this magnet 2, and the detected minute signal is amplified by an amplifier circuit 4 and then converted into a pulse by a pulse shaping circuit 5.

Therefore, in the rotational speed detection circuit made up of these components 2, 3, 4, and 5, the pulse shaping circuit output corresponds to the rotational speed of the shaft 1, and the pulse interval becomes smaller as the rotational speed increases. The output of this pulse shaping circuit is input to a rotation speed determining circuit comprising a basic pulse generating circuit 6, a comparison pulse generating circuit 7, and an error pulse detecting circuit 8. In this rotation speed determination circuit, a basic pulse is created from the output of the pulse shaping circuit by a basic pulse creation circuit 6, a comparison pulse is created from this basic pulse by a comparison pulse creation circuit 7, and both pulses are input to an error pulse detection circuit 8. The error pulse of both pulses is extracted and output. That is, when there is a pulse shaping circuit output A as shown in FIG. 3, the basic pulse generating circuit 6 operates at the rising edge of this pulse shaping circuit A and outputs a basic pulse L with a constant pulse width tl at the same period T as the output A. However, the comparison pulse generating circuit 7 operates at the falling edge of the basic pulse LO and outputs a comparison pulse C having a constant pulse width t2, and the error of both pulses LO and C is output as an error pulse 2. Therefore, when the rotation speed of the shaft 1 increases and the period T of the pulse shaping circuit output A and the basic pulse L becomes shorter, the error pulse pulse width t3 becomes longer, and conversely, the rotation speed of the shaft 1 decreases and the period T becomes longer. When this happens, the pulse width of error pulse 2 becomes smaller. This error pulse 2 is input to the next stage amplification/DC conversion circuit 9, where the discussion difference pulse 2 is amplified and converted to DC, and a DC voltage with a voltage value corresponding to the length of the pulse width of the error pulse is used to create a control pulse. It is input to the circuit 10. A throttle adjustment signal sent from a remote control transmitter of a radio control helicopter is input to this control pulse generation circuit 10, and the control pulse generation circuit 10 generates a control pulse synchronized with this throttle adjustment signal. It is generated from the DC output of the amplification/DC conversion circuit 9 and has a pulse width corresponding to the voltage value of this DC output.
The reason why control pulses are generated in synchronization with the throttle adjustment signal in this way is that when performing radio control of a radio-controlled helicopter, all control pulses sent from the transmitter to the receiver in the aircraft have a fixed period (for example, 2 hs). It was carried out in
This is because drive devices such as a throttle servo motor on the aircraft body side are also designed to be driven by this constant cycle control signal. Control pulses synchronized with the throttle adjustment signal are sent to the throttle control circuit 11 through the mode switching circuit 11.
The signal is sent to the servo motor, and the servo motor is driven to adjust the throttle function and control the rotation speed of the shaft (main rotor) 1 so that it approaches the set rotation speed. When the number of rotations of the main rotor settles down to the set number of rotations, the pulse width of the error pulse from the error pulse detection circuit 8 is fixed to a constant value, and thereafter the number of rotations of the main rotor is maintained at the set number of rotations. When the load on the main rotor increases or decreases due to the pitch angle change operation and the rotation speed changes, the pulse width of the second error pulse changes as described above, and the throttle servo motor is driven so that the rotation speed approaches the set rotation speed again. . When the main rotor's rotational speed approaches the set rotational speed, in order to prevent the main rotor's rotational speed from exceeding the set rotational speed, the amplification/DC conversion circuit 9 is connected to the throttle servo motor. The DC voltage input to the control pulse generating circuit 10' is adjusted by applying negative feedback to the control pulse generating circuit 10'. For example, when the main rotor rotation speed is lower than the set rotation speed, the pulse width of the error pulse is small and the amplification/DC conversion circuit 9 sends a high DC voltage to the control pulse generation circuit 10 to drive the throttle servo motor. ,
The rotation speed of the main rotor is increased, but as the rotation speed of the main rotor approaches the set rotation speed, the terminal voltage of the throttle servo motor is fed back and acts in the direction of canceling the DC output of the amplification/DC conversion circuit 9. Therefore, the movement of the throttle servo motor is suppressed, and the throttle servo motor is correctly stopped at the desired position. As is clear from the above explanation, the set rotational speed of the main rotor is determined by varying the pulse widths t, t2 of the pulses generated by the basic pulse generation circuit 6 and the comparison pulse generation circuit 7, and by changing the margin appearing in the output of the error pulse detection circuit 8. The pulse width t3 of the second pulse may be adjusted to be different for the same rotation speed.

Therefore, in the present invention, a 1.1 ms subtraction circuit 12, an amplifier circuit 13, and a DC conversion circuit 14 are provided. That is, in order to change the set rotation speed, a set rotation speed adjustment signal is sent from the transmitter side. This signal is a set rotation speed adjustment signal with a pulse width of 1.1ms to 1.9hs.
The set rotation speed is commanded to be changed by varying the pulse width between ms and 1.9hs. On the other hand, in the receiver, the set rotation speed adjustment signal sent from the transmitter is input into a 1.1 ms subtraction circuit 12 to generate a signal of 0 to 0.8 hs. The reason for subtracting in this way is to increase the rate of change of the set rotation speed adjustment signal to clarify the adjustment operations of the basic pulse generation circuit 6 and comparison pulse generation circuit 7, and the 1.1ms subtraction circuit output is further amplified. After being sent to the circuit 13, it is converted to DC,
This is added to the basic pulse generation circuit 6 and the comparison pulse generation circuit 7 to change the pulse widths t, , etc. generated by these circuits. Further, the above control pulse is sent to the throttle servo motor, while being branched to the 1.1ms subtraction circuit 1.
5, and the amount of change in the control pulse that drives the throttle servo motor is derived.

Subtracting 1.1ms from the control pulse is because the control pulse normally changes between 1.1ms and 1.9hs to control the throttle servo motor, and subtracting 1.1ms above will result in the control pulse The amount of change in is 0
This is because the value is extracted at a large rate of change of ~0.8 hs. Next, the 1.1 ms subtraction circuit output is sent to the mixing amount setter 16, where it is shaped into a mixing pulse having the required peak value.The mixing pulse is then input to the DC conversion circuit 17, and the DC The output is input to a mixing pulse re-creation circuit 18, and the circuit 18 is triggered by the ladder adjustment signal to create a mixing pulse synchronized with the rising edge of the ladder adjustment signal. In this mixing pulse re-creation circuit 18, when the mixing amount is 0, 1. A mixing pulse for shoe s (therefore, the mixing pulse is 1.50 Qms) is created. This is added together with the ladder adjustment pulse to the addition circuit 19 to add both signals, and then in the 1.8hs subtraction circuit 20 described in 1. shoes s
After subtracting the additional amount, add the rudder/servo motor. In this way, the rudder servo motor is driven according to the amount that the throttle servo motor is driven by the control pulse, and the recoil torque of the aircraft caused by fluctuations in the main rotor load and engine output can be reduced by changing the pitch of the tail rotor. can be canceled out. That is, fluctuations in the load on the main rotor and fluctuations in the engine output lead to changes in the reaction torque, while fluctuations in the load on the main rotor and the engine output appear as changes in the rotational speed of the main rotor. Since the main rotor rotational speed automatic control circuit generates a control pulse in the direction of making the rotational speed constant as the rotational speed of the main rotor changes, the control pulse for correcting the rotational speed is applied to the tail rotor pitch angle. If this signal is used as a correction signal and mixed with a rudder adjustment signal to drive the rudder servo motor, the increase or decrease in reverse torque will be automatically canceled out. Next, to explain the mode switching circuit 11 using FIG. 2, the mode selection signal sent from the transmitter has a pulse width of 0.9hs in manual mode and 2.1ms in automatic control mode. ing.

This mode selection signal is 1.5hs basic pulse generation circuit 2
1 and is sent to the pulse comparison circuit 22, and the reference pulse generation circuit 21 generates a basic pulse of 1.8 hs and inputs it to the pulse comparison circuit 22. Therefore, the pulse comparison circuit 22 compares this 1.9hs reference pulse with 0.9hs or 2.1ms.
The mode selection signal is 0.9.
hs, outputs 18hs pulse, 2.1ms
No output when . The next-stage DC conversion circuit 23 converts the output of the pulse comparison circuit 22 into DC, and therefore outputs an "H" level in manual mode and an "L" level in automatic control mode. This output is sent to a switching pulse generation circuit 25 and an input selection circuit 26 via a Schmitt circuit 24. The control pulse generation circuit 25 receives control pulses from the control pulse generation circuit 10 described above, and the Schmitt circuit 24 receives control pulses from the switching pulse generation circuit 2 in the manual mode.
5, the circuit 25 always outputs a pulse with a width of 1 ms. Furthermore, in automatic control mode, the circuit 25
Trigger the pulse width of its output from lms to 2h
It expands beyond s. Further, the Schmitt circuit 24 functions to send the a terminal input of the input selection circuit 26 to the throttle servo motor in the manual mode, and to send the b terminal input to the throttle servo motor in the automatic control mode.
The long pulse priority circuit 27 receives the throttle adjustment signal and the switching pulse generation circuit output, compares the two, and inputs a long pulse signal to the short pulse priority circuit 28. The control pulse is input to the short pulse priority circuit 28, which is configured to compare this control pulse with the output of the long pulse priority circuit and send a short pulse signal to the b terminal of the input selection circuit 26. There is. Therefore, when the engine is started and placed in manual mode, a 0.9hs width pulse is input to the pulse comparison circuit 22, and this circuit 22
An 18 hs width pulse is outputted from the input selector circuit 24, and the output of the DC converter circuit becomes "H" level, and the a terminal of the input selection circuit 26 is selected by the Schmitt circuit 24, so that a throttle adjustment signal is sent to the throttle servo motor.

At the time of starting the engine, a throttle adjustment signal that is slightly larger than lms is sent, so the throttle is narrowed down and the main rotor rotates at a relatively low speed. Next, when the mode selection signal is set to 2.1ms, the input selection circuit 26
selects the b terminal input, and the switching pulse generation circuit 2
5 is triggered, and the circuit output is gradually widened from the lms width. In the long pulse priority circuit 27, at the beginning of mode switching, the throttle adjustment information G has a longer width than the switching pulse H, as shown in the graph of FIG. As the width is expanded, the switching pulse ho is prioritized and output from one point.
Each signal is sent to a short pulse priority circuit 28. When the engine is first started, the throttle is narrowed and the main rotor rotational speed is low as described above, so the control pulse has a sufficiently large pulse width of 2 ms or more as shown in Figure 4 (that is, the control pulse has a sufficiently large pulse width of 2 ms or more). (having a force in the direction of driving the motor to a large extent and increasing the main rotor rotational speed), therefore, the throttle adjustment speed is shorter than that,
A switching pulse is then output, which passes through the input selection circuit 26 to the throttle servo motor. Since the pulse width of the switching pulse ho is expanded as shown in FIG. 4, the throttle servo motor is also driven in the direction of opening the throttle, and therefore the rotational speed of the main rotor increases. Next, as the main rotor rotational speed increases, the pulse width of the control pulse becomes striped, while the pulse width of the switching pulse ho changes or becomes hidden as described above. The pulse widths of the two match. This is the point in time when the main rotor rotation speed reaches the set rotation speed, and at this point, the short pulse priority circuit 28 outputs a control pulse, and the throttle servo motor is controlled by this control pulse. The rotational speed settles to the set rotational speed, and the operation shifts to the automatic control mode as described in the explanation of FIG. In the above embodiment, the control pulse generation circuit 1 of the main rotor rotational speed automatic control circuit
0 output, that is, a control pulse is applied to the throttle servo motor, while 1 output is applied as a signal for rudder servo motor correction.
．． 1ms subtraction circuit 15, but in radio control helicopters that are not equipped with the above-mentioned automatic stopper rotor rotation speed control circuit, the throttle adjustment signal is added directly to the 1.1ms subtraction circuit from the transmitter side. The rudder servo motor may be controlled in response to throttle operation. As detailed above, according to the present invention, the main row rotational speed is constantly detected on the helicopter body side independently from the remote throttle control by the pilot on the ground, and this is set as the set rotational speed. As the detected rotation speed increases or decreases with respect to the set rotation speed, control pulses are given to the throttle servo motor to adjust the opening of the throttle so that the main rotor rotation speed settles to the set rotation speed. The pulse is used as a tail rotor pitch angle correction signal, which is mixed into the rudder adjustment signal, and then added to the rudder servo motor to automatically correct the tail rotor pitch angle, and also to prevent recoil of the aircraft due to changes in main rotor rotation speed. Since it cancels out the torque, even if the load on the main rotor or the engine output fluctuates unexpectedly due to natural and external forces applied to the aircraft, such as the transfer lift mentioned at the beginning, the The pitch angle of the tail rotor is automatically changed in response to the above-mentioned fluctuations without any manual remote control, and the reaction torque is canceled. Therefore, the helicopter can fly stably without rotating its body.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 is a block diagram of a mode switching circuit, Fig. 3 is a signal waveform diagram used to explain the circuit shown in Fig. 1, and Fig. 4 is a diagram explaining mode switching operation. It is. 1. ...Main rotor shaft, 2-5...Rotation speed detection circuit, 6, 7, 8...Rotation speed judgment circuit, 9...Amplification
DC conversion circuit, 10... control pulse creation circuit, 16.
...Mixing amount setting device, 18...Mixing pulse re-creation circuit, 19...Addition circuit. *Fushishige Rin Momesato Boat/Snake Fishing

Claims (1)

[Claims] 1 The rotation speed detection circuits 2, 3, 4, and 5 detect the rotation speed of the main rotor shaft 1, and compare this detected rotation speed with the set rotation speed sent from the remote control transmitter to generate an error signal. The output rotation speed determination circuits 6, 7, and 8, the amplification/DC conversion circuit 9 that converts this error signal into a DC voltage signal, and the throttle adjustment signal that converts this DC voltage signal from the remote control transmitter. a control pulse generation circuit 10 that converts the control pulses into control pulses synchronized with the control pulses and supplies the control pulses as drive signals for the throttle servo motor;
A mixing amount setter 16 that shapes the control pulse into a mixing pulse having a required peak value as a tail rotor pitch angle correction signal, and synchronizes this mixing pulse with the rudder adjustment signal sent from the remote control transmitter. A tail rotor pitch of a radio control helicopter, which includes a mixing pulse re-creation circuit 18 for re-creating the re-created mixing pulse, and an addition circuit 19 that adds the re-created mixing pulse to the rudder adjustment signal and sends it to the rudder servo motor. Angle control device.