JP2003190659A - Modulation method of radio-controlled transmitter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a modulation method of a radio-controlled transmitter that can reliably recognize external noise, and further can narrow transmission bandwidth without making operation response slow. <P>SOLUTION: The voltage of inputs 1 and 2 are fetched into a CPU12 from first and second input sections 13 and 14, half the pulse width in an operation pulse signal corresponding to the voltage of the inputs 1 and 2 is allocated to an operation high-level pulse (VH), and the remaining half of the pulse width is allocated to an operation low-level pulse (VL). Additionally, the remaining pulse width where the pulse width of the operation pulse signal is subtracted from 1 frame is set to be a synchronous pulse signal. The pulse width of the synchronous pulse signal is set to be a remaining pulse width, and the half of the remaining pulse width is modulated to a synchronous high-level pulse (VH). Further, the remaining half of the remaining pulse width is modulated to a synchronous low-level pulse (VL). <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a modulation method for a radio control transmitter, and more particularly to an operation pulse signal included in one frame of the operation signal in the radio control transmitter when transmitting the operation signal from the radio control transmitter to the receiver. And a modulation method of a radio control transmitter for modulating a sync pulse signal.

[0002]

2. Description of the Related Art For example, a radio control transmitter is known as one for remotely controlling a model car. The conventional radio control transmitter takes in an input voltage into a CPU and outputs an operation signal corresponding to the input voltage to the CPU. Is to operate the model car by transmitting it from the receiver to the model car receiver.

A PPM (pulse position modulation) signal is known as an operation signal transmitted from the CPU to the receiver. According to this PPM signal system, as shown in FIG. 7, for example, the input first signal 100 for controlling the steering wheel of the model car and the input second signal 101 for controlling the accelerator of the model car are transmitted to the receiver as pulse signals. Thus, it is possible to control the steering wheel and the accelerator (the number of rotations of the motor) of the model car.

Generally, the input first signal 100 is used as the operation signal.
And a synchronization signal 10 for synchronizing the second input signal 101
2 are provided, and the input first signal 100 and the input second signal 10 are provided.
1 and the synchronization signal 102 make up one frame.

However, in the PPM signal, when the external noise 103 is generated as shown in FIG. 7, the external noise 103 is easily misidentified as the input first signal 100, the input second signal 101 or the synchronization signal 102. As a result, there is a problem that the model car is affected by the external noise 103 and malfunctions.

A PCM (Pulse Code Modulation) signal is known as a signal improved from this drawback. In this PCM signal system, an input first signal and an input second signal for controlling a steering wheel and an accelerator are AD-converted into digital data, which is serially output. At this time, in order to recognize the external noise, for example, the number of 1s of the digital data is summed and the noise identification signal of the lower 8 bits is output.

By comparing the lower 8 bits in the binary system of the total number of 1s of 1 frame of digital data with FIG. 8, it is determined whether external noise has entered this 1 frame. Can be confirmed.

[0008]

However, in PCM transmission, it is necessary to newly output a noise identification signal in order to recognize external noise. For this reason, this noise identification signal, which is not normally necessary, must be sent every time. Further, there is a problem that the processing on the transmitting side and the processing on the receiving side become complicated.

On the other hand, the transmission band used when operating the model car remotely is set to, for example, 25.4 to 25.6 MHz. Therefore, in order to remotely operate a plurality of model cars, in order to remotely operate each model car, the band of 25.4 to 25.6 MHz is divided into a plurality of usage bands, and each of the usage bands is used. Bands are distributed to each radio-controlled car.

As described above, when the band of 25.4 to 25.6 MHz is allocated to a plurality of used bands, the used band of each radio controlled car becomes narrower in transmission band. In the case of the PCM signal system, if the transmission band of the used band is narrowed, the modulation rate (that is, the number of frames per unit time) must be reduced, which causes a problem that the operation response becomes slow.

The present invention provides a modulation method for a radio control transmitter, which does not require a new noise discrimination signal to be output for recognizing external noise, and can narrow the transmission band without slowing the operation response. Then, all the above problems are to be solved.

[0012]

In order to achieve the above object, the first aspect of the present invention is to control the input voltage of a radio control transmitter by using a CP voltage.
When the actuator receives the operation signal corresponding to this input voltage from the radio-controlled transmitter to the receiver and drives the actuator, the CPU supplies the operation pulse signal and the synchronization pulse signal included in one frame of this operation signal. A modulation method of a radio control transmitter for modulating, wherein the operation pulse signal has an operation high level pulse of 1/2 of a pulse width of the pulse signal and an operation low level pulse of the remaining 1/2. The signal is modulated and transmitted from the CPU to the receiver, and the remaining pulse width remaining after subtracting the pulse width of the operation pulse signal from the one frame is set as the synchronization pulse signal. / 2 is modulated so as to be a synchronous high level pulse, and the remaining 1/2 is modulated so as to be a synchronous low level and transmitted from the CPU to the receiver. To.

In the above-mentioned modulation method for the radio controlled transmitter according to the present invention, ½ of the pulse width of the operation pulse signal is modulated to become the operation high level pulse, and the remaining ½ is modulated to the operation low level pulse, One half of the sync pulse signal is modulated so that the sync high level pulse and the other half are sync low level.

Thus, for example, when the operation low level pulse of the operation pulse signal includes the foreign nozzle, the pulse widths of the operation high level pulse and the operation low level pulse are not the same, so check this. Thus, it is possible to reliably detect that the external noise has entered. In addition, even when external noise enters the sync pulse signal, the external noise can be reliably detected in the same manner.

According to a second aspect of the present invention, a plurality of the operation pulse signals are provided in the one frame.

By providing a plurality of operation pulse signals in one frame, it becomes possible to control a plurality of controlled parts such as the steering wheel and accelerator of a model car.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a modulation method for a radio control transmitter according to the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a schematic diagram showing a radio control transmitter for implementing a modulation method for a radio control transmitter according to the present invention, and FIG. 2 is an explanatory diagram showing a modulation method for the radio control transmitter according to the present invention.
FIG. 4 is a flowchart illustrating a modulation method of a radio control transmitter according to the present invention, FIG. 4 is a graph showing a relationship between voltage and pulse width in the modulation method of the radio control transmitter according to the present invention, and FIG. 5 is a radio control transmitter according to the present invention. 6 is a graph showing the relationship between the voltage and the pulse width of the modulation method in more detail, FIG. 6 shows a case where a constant frequency band allocated for radio control transmission is adopted when the modulation method of the radio control transmitter according to the present invention is adopted. It is a graph which shows the example which put in a plurality of bands.

The radio-controlled transmitter 10 shown in FIG. 1 is provided with a CPU 12 for transmitting a control signal to a model car 11, and this CPU C
A first input unit 13 that transmits a voltage for controlling the steering wheel of the model car 11 to the PU 12 and a second input unit 14 that transmits a voltage for controlling the accelerator (motor rotation speed) of the model car 11 to the CPU 12. The CPU 12 according to the voltage transmitted from the first and second input units 13 and 14.
To transmit a signal for controlling the steering wheel of the model car 11 and a signal for controlling the accelerator to the receiver 11a of the model car 11. In addition, radio controlled transmitter 1
0 includes a clock transmission unit 15 for synchronizing signals.

According to the radio-controlled transmitter 10, the input voltages of the input 1 and the input 2 are taken into the CPU 12 from the first and second input sections 13 and 14, respectively, and the CPU 12 modulates the operation signal corresponding to the input voltage. Model car 1 with modulated signal
The steering wheel and the accelerator can be controlled by transmitting the signal to the first receiver 11a and driving an actuator (not shown) based on the signal from the receiver 11a.

The modulation method of the radio control transmitter 10 will be described below with reference to FIGS. 2 and 3. First, in ST10, the input 1 voltage is taken into the CPU 12 from the first input unit 13. Next, in ST11, a half pulse width (S1) of the operation pulse signal corresponding to the input 1 voltage is assigned to the operation high level pulse (VH), and the remaining 1/2 pulse width (S1) is allocated. The operation high level pulse (VH) and the operation low level pulse (VL) which are modulated by the CPU 12 so as to be assigned to the operation low level pulse (VL) are modulated.
Is transmitted from the CPU 12 to the receiver 11a of the model car 11.

Next, in ST12, the second input section 1
Input 2 voltage from 4 is taken into CPU 12. Then, ST
At 13, the half of the operation pulse signal corresponding to the input 2 voltage (S2) is allocated to the operation high level pulse (VH), and the remaining 1/2 (S2) is allocated to the operation low level pulse (VL). ), And the modulated operation high level pulse (VH) and operation low level pulse (VL) are transmitted from the CPU 12 to the receiver 11a of the model car 11.

Next, in ST14, the pulse width of the operation panel signal from one frame (that is, 2 × S1 + 2 ×).
The remaining pulse width (2 × S3) remaining after subtracting S2) is set as the sync pulse signal. The pulse width of this synchronizing pulse signal is defined as the remaining pulse width (2 × S3), and 1/2 (S) of the remaining pulse width
3) Modulates synchronous high-level pulse (VH) to CPU
From 12 to the receiver 11a of the model car 11.

Subsequently, in ST15, the remaining 1/2 (S3) of the residual pulse width is modulated so as to become a synchronous low level pulse (VL) and transmitted from the CPU 12 to the receiver 11a of the model car 11.

On the other hand, on the receiver 11a side, the sync pulse signal is recognized after confirming that the pulse widths of the sync high level pulse (VH) and the sync low level pulse (VL) are the same width (S3). Thus, the operation signal for input 1 and the operation signal for input 2 can be synchronized.

On the side of the receiver 11a, it is confirmed that the pulse widths of the operation high level pulse (VH) and the operation low level pulse (VL) of the input 1 are the same width (S1), and the input 1 Recognize the operation pulse signal of. Further, on the receiver 11a side, it is confirmed that the pulse widths of the operation high level pulse (VH) and the operation low level pulse (VL) of the input 2 are the same width (S2), and the input 2
Recognize the operation pulse signal for.

As described above, the operation signal for input 1 and the operation signal for input 2 can be synchronized by recognizing the synchronizing pulse signal, so that the operation signal for input 1 and the operation for input 2 are operated. The accelerator and steering wheel of the radio controlled car 11 can be controlled based on the signal.

Here, for example, when the foreign nozzle 16 enters the operating low level pulse (VL) of the input 1, this external noise 16 is recognized as the operating high level pulse (VH). Therefore, the operation high level pulse (V
The pulse width of H) becomes larger than S1, and the pulse width of the operation low level pulse (VL) becomes smaller than S1.

Therefore, the operation high level pulse (VH)
And the pulse width of the operation low level pulse (VL) are not the same width (S1). This allows the receiver 11a to detect that external noise has entered one frame of the transmission signal.

As described above, when the external noise is detected, the output from the CPU of the receiver 11a to the actuator is stopped or the previous normal output is output again to prevent the malfunction due to the external noise. can do. It should be noted that one frame in which external noise has entered can be canceled by discarding it in the trash box of the CPU of the receiver 11a (so-called trash box of the computer).

Further, even when external noise enters the second input signal or the synchronizing pulse signal, the external noise can be detected in the same manner. As a result, the input first signal and the input second signal can be accurately detected, and the location of the synchronization signal can also be accurately detected. The steering wheel and accelerator can be controlled accurately.

FIG. 4 is a graph showing the relationship between the input voltage and the pulse width. In this graph, the horizontal axis shows the input voltage and the vertical axis shows the pulse width. According to the graph line g1, the pulse width when the input voltage is 2 V is 1 ms (micro.
Second (seconds), and the pulse width is 2 ms when the input voltage is 3V. From this graph line g1, it can be seen that the pulse width changes linearly, that is, linearly, corresponding to the change in the input voltage.

This change in the input voltage is achieved by operating the first and second input sections 13 and 14 of the radio-controlled transmitter 10 shown in FIG. 1 to change the resistance values of these input sections 13 and 14. You can do it.

Next, referring to FIG. 5, the graph line g shown in FIG.
1 will be described more specifically. As shown in FIG. 5, when the input voltage is set to 2V, the pulse widths of the high level pulse (VH) and the low level pulse (VL) are each 1 ms, and when the input voltage is set to 2.5V, the high level pulse (VH) is set. ) And the low-level pulse (VL) each have a pulse width of 1.5 ms. Further, when the input voltage is set to 3V, the pulse widths of the high level pulse (VH) and the low level pulse (VL) are each 2 ms.

Thus, in comparison with PPM and PCM,
Since it does not output pulses that are narrower than necessary,
The frequency band required for the operation signal can be narrowed while the operation response is normally maintained.

As a result, as shown in FIG. 6, a fixed frequency band (25.4 to
25.6 MHz) with multiple bands 18a, 18b,
18c ... can be inserted, for example, a plurality of bands 18
It becomes possible to play a game using a, 18b, 18c, ...

In the above embodiment, the example applied to the radio controlled car has been described, but the present invention is not limited to this.
The same effect can be obtained even if it is adopted in other radio controlled devices. Further, in the above-described embodiment, the constant frequency band assigned for radio-controlled transmission is described as an example of 25.4 to 25.6 MHz, but similar effects can be obtained for other frequency bands. it can.

Further, in the above embodiment, FIG. 4 and FIG.
Although the pulse width has been described as 1 ms, 1.5 ms, or 2 ms as an example, the pulse width is not limited to this and can be appropriately selected.

Further, in the above-described embodiment, an example in which the radio control transmitter 10 controls the handle and accelerator of the radio control car has been described, but the present invention is not limited to this, and it is also possible to control other controlled parts.

[0039]

As described above, according to the modulation method for a radio controlled transmitter according to claim 1, 1/2 of the pulse width of the operation pulse signal is an operation high level pulse, and the remaining 1/2 is an operation low level pulse. The sync pulse signal is modulated so that 1/2 of the sync pulse signal is a sync high level pulse and the other half is a sync low level pulse.

Thus, for example, when the operation low level pulse of the operation pulse signal includes the foreign nozzle, the pulse widths of the operation high level pulse and the operation low level pulse are not the same, so check this. Thus, it is possible to reliably detect that the external noise has entered.

Further, even when the external noise enters the sync pulse signal, the external noise can be surely detected in the same manner. Therefore, the external noise can be reliably recognized without newly outputting the noise identification signal dedicated to the detection of the external noise as in the conventional case.

According to the second aspect, by providing a plurality of operation pulse signals in one frame, it becomes possible to control a plurality of controlled parts such as a steering wheel and an accelerator of a model car. As a result, the modulation method of the present invention can be preferably used as an operation signal for a model car.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a radio control transmitter for implementing a modulation method of a radio control transmitter according to the present invention.

FIG. 2 is an explanatory diagram showing a modulation method of a radio-controlled transmitter according to the present invention.

FIG. 3 is a flowchart illustrating a modulation method of a radio-controlled transmitter according to the present invention.

FIG. 4 is a graph showing a relationship between voltage and pulse width in a modulation method of a radio control transmitter according to the present invention.

FIG. 5 is a graph more specifically showing the relationship between the voltage and the pulse width in the modulation method of the radio control transmitter according to the present invention.

FIG. 6 is a graph showing an example in which a plurality of bands are put in a constant frequency band assigned for radio control transmission when the modulation method of the radio control transmitter according to the present invention is adopted.

FIG. 7 is an explanatory diagram showing a PPM modulation method of a conventional radio control transmitter.

FIG. 8 is an explanatory diagram showing a PCM modulation method of a conventional radio control transmitter.

[Explanation of symbols]

10 ... Radio control transmitter 11 ... RC car 11a ... RC receiver 12 ... CPU of radio control transmitter 13 ... First input section 14 ... Second input section S1, S2, S3 ... Pulse width

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H04Q 9/00 311 H04Q 9/00 311L 9/14 9/14 DF term (reference) 2C150 CA08 DA06 DK02 DK11 EB01 ED02 ED10 ED13 EF39 FA24 5K004 AA03 DA03 DD00 5K048 AA09 BA09 DB01 EA03 EB02 FA07 5K060 BB08 CC11 DD08 FF07 HH32

Claims (2)

[Claims] 1. The input voltage of a radio-controlled transmitter is set to CP.
When the actuator receives the operation signal corresponding to this input voltage from the radio-controlled transmitter to the receiver and drives the actuator, the CPU supplies the operation pulse signal and the synchronization pulse signal included in one frame of this operation signal. A modulation method of a radio control transmitter for modulating, wherein the operation pulse signal is one of a pulse width of the pulse signal.
/ 2 is modulated so as to become an operation high-level pulse, and the remaining 1/2 is modulated to be an operation low-level pulse, which is transmitted from the CPU to the receiver, and the remaining one obtained by subtracting the pulse width of the operation pulse signal from the one frame. The remaining pulse width is set as a synchronizing pulse signal, and the synchronizing pulse signal is modulated so that ½ of the remaining pulse width becomes a synchronous high level pulse and the remaining ½ becomes a synchronous low level pulse, and the remaining pulse width is modulated by the CPU. A radio-controlled transmitter modulation method characterized in that it is transmitted to a receiver. 2. The modulation method for a radio controlled transmitter according to claim 1, wherein a plurality of the operation pulse signals are provided in the one frame.