JPH0853963A - Remote operation device - Google Patents

Abstract

PURPOSE:To widen an operation range while restraining the occurrence of a malfunction caused by a noise in a remote operation device to perform, for example, opening-closing of a door lock of a vehicle or starting-stopping or the like of an engine by using a radio wave. CONSTITUTION:In transmission, after a carrier wave of a low frequency is modulated by a key signal, a carrier wave of a high frequency is modulated and transmitted by this carrier wave of the low frequency, and in reception, a received high frequency signal is detected after it is passed through a band- pass filter 12, and a low frequency signal is demodulated, and the demodulated low frequency signal is detected after it is passed through a band-pass filter 61, and a key signal is taken out. Therefore, even if a noise is received together with an object signal since a band of the band-pass filter 12 is wide, a signal after passing through this band pass filter 12 is detected, and when it is again passed through the band-pass filter 61 after a low frequency signal is demodulated, since a noise can be removed, even a signal of a small signal level can be taken out, so that a remote control operable range can be widened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a remote control device which uses radio waves to open and close a door lock of a vehicle and start / stop an engine.

[0002]

2. Description of the Related Art Conventionally, there is a remote control device for opening and closing a vehicle door lock and starting / stopping an engine using radio waves. This type of remote control device receives a command transmitted from a transmitter (remote controller) that transmits commands instructing various operations, analyzes the command, and opens and closes the door lock based on the result. Or engine start /
It is composed of a receiving device for stopping. The transmitter is carried by a person using the vehicle, such as a driver, and the receiver is mounted inside the vehicle. Here, FIG. 5 is a block diagram showing a schematic configuration of a conventional remote control device. In this figure,
A transmitter 1 includes a key input unit 2 for generating a key code corresponding to each command, a signal generator 3 for generating a key signal from the key code output from the key input unit 2, and a signal generator for this signal. A high frequency modulator 4 that modulates a high frequency carrier wave with a key signal output from the device 3, and a power amplifier 5 that power-amplifies the carrier wave modulated by the high frequency modulator 4 and outputs the amplified carrier wave to the antenna 6.

Reference numeral 10 denotes a receiving device, which is composed of a bandpass filter 12 that passes the frequency band of the signal transmitted from the transmitting device 1 among the signals input through the antenna 11, and a signal that has passed through this bandpass filter 12. A detector 13 for demodulating the key signal, an amplifier 14 for amplifying the key signal demodulated by the detector 13, and an amplifier 14
The control signal output unit 15 outputs a control signal based on the key signal amplified in.

The output of the control signal output section 15 is input to a door lock controller or an engine controller (not shown). The door lock controller controls the door lock mechanism. When a control signal for locking the door is input from the control signal output section 15, the door lock controller controls the door lock mechanism to lock the door. Further, when a control signal for unlocking the door is input, the door lock mechanism is controlled to unlock. The engine controller controls the engine. When the control signal for starting the engine from the control signal output unit 15 is input, the engine is started, and when the control signal for stopping the engine is input, the engine is stopped.

In such a configuration, when the driver carrying the transmitter 1 presses a desired key of the transmitter 1, for example, a key for unlocking the door, a key code for unlocking the door is output, and further, A key signal corresponding to the key code is output. Then, after the carrier wave is modulated by this key signal and power is amplified, it is output from the antenna 6 to the hollow. On the other hand, in the receiving device 10, the high frequency signal from the transmitting device 1 captured by the antenna 11 passes through the bandpass filter 12, and then the detector 13 demodulates the key signal. Then, the demodulated key signal is power-amplified and a control signal based on this key signal is output. In this case, since the control signal is for unlocking the door, the door lock controller receiving this control signal controls the door lock mechanism to unlock the door.
This releases the door lock.

[0006]

However, such a conventional remote control device has the following problems. Although miniaturization of the transmission device is required from the viewpoint of portability, the miniaturization also requires the use of a small battery, so the transmission output cannot be increased so much from the viewpoint of power supply capacity. The operable range cannot be widened. Since there is a limit to the transmission output that can be used without permission by the Radio Law, it is general to increase the receiving sensitivity of the receiving device in order to extend the distance from the transmitting device to the receiving device. However, since noise other than the intended signal is easily picked up by increasing the receiving sensitivity, there is a problem that malfunction is likely to occur. In this case, as shown in FIG. 6, in the normal setting of the receiving sensitivity, the target signal can be extracted by passing through the band pass fill. However, if the receiving sensitivity is increased, as shown in FIG. As a result, the signal level rises, so that signals (noise) other than the target signal are also extracted.

In order to solve the problem of (1), the target signal and noise are separated while increasing the receiving sensitivity.
As shown in (1), a method of narrowing the band of the bandpass filter of the receiving device and extracting only the source signal is generally used. However, with this method, it is necessary to increase the accuracy of the center frequency and transmission frequency of the bandpass filter,
There is a drawback in that it is necessary to manage variations in individual parts and make fine adjustments in manufacturing.

Therefore, an object of the present invention is to provide a remote control device capable of expanding the operation range while suppressing the occurrence of malfunction due to noise.

[0009]

In order to achieve the above object, a remote control device according to the present invention includes transmitting means for transmitting a key signal output by operating an operation key, and a key signal transmitted by the transmitting means. And a receiving means for outputting a control signal for opening and closing a door lock of the vehicle or starting / stopping an engine of the vehicle by receiving the control signal. It has a low frequency modulating means for modulating a carrier wave and a high frequency modulating means for modulating a high frequency carrier wave by the output of the low frequency modulating means, and the receiving means passes the high frequency signal transmitted from the transmitting means. A first filter having a band, a first detecting means for demodulating a low frequency signal from a high frequency signal passing through the first filter, and a low frequency signal demodulated by the first detecting means. A second filter having a pass band for allowing the key signal component of (1) to pass through, and a second detecting means for demodulating the key signal from the key signal component of the low frequency signal passing through the second filter. To do.

[0010]

According to the present invention, in transmission, a low frequency carrier is modulated with a key signal, and then a high frequency carrier is modulated with this low frequency carrier and transmitted. Upon reception, the received high frequency signal is passed through the first filter, and then detected and demodulated to the low frequency signal. Then, after passing the demodulated low frequency signal through the second filter, it is detected to extract the key signal. Therefore, even if noise is received together with the target signal due to the wide band of the first filter, the signal after passing through the first filter is detected, the low frequency signal is demodulated, and then passed through the second filter again. By doing so, noise can be removed. As a result, the reception sensitivity can be increased even if the selection accuracy of the first filter is low, and therefore a signal with a low signal level can be extracted.
It becomes possible to widen the operable range of the remote controller.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a schematic configuration of an embodiment of a remote control device according to the present invention. In this figure, the same parts as those in FIG. 5 described above are designated by the same reference numerals and the description thereof will be omitted. In the figure, reference numeral 50 denotes a transmitter (remote controller), which includes a key input unit 2, a signal generator 3, a low frequency modulator 51, a high frequency modulator 4, a power amplifier 5, and an antenna 6. The low frequency modulator 51 modulates a low frequency carrier wave by the key signal from the signal generator 3. The high frequency modulator 4 receives the low frequency carrier from the low frequency modulator 51, and modulates the high frequency carrier by the low frequency carrier. The high frequency carrier wave modulated by the high frequency modulator 4 is amplified by the power amplifier 5 and output from the antenna 6 to the hollow.

FIG. 2 is a diagram showing an example of a waveform in the AM (amplitude) modulation. When low frequency modulation is performed with the key signal shown in (a), it becomes as shown in (b). When high frequency modulation is performed on the waveform, it becomes as shown in (c). (D)
[Fig. 4] is an enlarged view of a part of the high frequency modulation waveform shown in (c). On the other hand, FIG. 3 is a diagram showing an example of a waveform in FM (frequency) modulation. When low frequency modulation is performed with the key signal shown in (a), it becomes as shown in (b), and high frequency modulation is performed with this low frequency modulation waveform. Is performed, the result is as shown in (c). (D) is (c)
FIG. 3 is an enlarged view of a part of the high frequency modulation waveform shown in FIG. The frequency of the low frequency carrier wave is, for example, 40 kHz, and the frequency of the high frequency carrier wave is, for example, 300 MHz. It should be noted that these frequencies are merely examples, and what frequency is selected is arbitrary.

Returning to FIG. 1, reference numeral 60 denotes a receiver, which is a high-frequency bandpass filter 12, a detector 13, a low-frequency bandpass filter 61, a detector 62, an amplifier 63, and a control signal. The band pass filter 61 is composed of the output section 15 and passes the low frequency signal including the key signal demodulated by the detector 13. The detector 62 demodulates the key signal from the low frequency signal that has passed through the band pass filter 61. The amplifier 63 amplifies the key signal demodulated by the detector 62. The amplifier 63 has an automatic gain adjustment function by an AGC circuit, and automatically changes the amplification factor according to the input signal level. In addition to the automatic gain adjustment, manual gain adjustment may be possible. Further, each of the bandpass filters 12 and 61 may be a passive filter such as an LC type filter or an active filter including a passive filter and an operational amplifier.

Here, FIG. 4 is a diagram showing signal processing in the receiving device 60, and as shown in FIG.
By passing the high-frequency signal captured in step 3 through the bandpass filter 12, a high frequency signal including a key signal component is extracted as shown in (b). At this time, since the bandpass filter 12 is not a narrow passband as shown in FIG. 8 but a normal passband, a high-frequency signal containing a key signal component and noise having a similar frequency are together. Pass 12. Bandpass filter 12
The high frequency signal that has passed through is detected by the detector 13 as a low frequency signal including the key signal. Then, as shown in (c), the low-frequency signal including the key signal is passed through the bandpass filter 61, whereby a substantially key signal is extracted as shown in (d).

The modulator 4 corresponds to high frequency modulation means,
The bandpass filter 12 corresponds to the first filter, and the detector 13 corresponds to the first detecting means. The transmitter 50 corresponds to the transmitter, the modulator 51 corresponds to the low frequency modulator, and the receiver 60 corresponds to the receiver. Also,
The bandpass filter 61 corresponds to the second filter, and the detector 62 corresponds to the second detecting means.

In such a structure, when the driver carrying the transmitter 50 presses a desired key of the transmitter 50, for example, a key for unlocking the door of the vehicle, a key code for unlocking the door is output. , And a key signal corresponding to the key code is output. Then, the low-frequency carrier wave is modulated by this key signal. Then, the high-frequency carrier wave is modulated by this low-frequency carrier wave, and the power is amplified, and then output from the antenna 6 to the hollow. On the other hand, in the receiving device 60, the high frequency signal from the transmitting device 50 captured by the antenna 11 passes through the band pass filter 12, and then the low frequency signal including the key signal is demodulated by the detector 13. Then, after the low-frequency signal including the demodulated key signal passes through the bandpass filter 61, the detector 62 demodulates the key signal. The demodulated key signal is amplified and then input to the control signal output unit 15, and a control signal based on the key signal is output. In this case, since the control signal is for unlocking the door, the door lock controller receiving this control signal controls the door lock mechanism to unlock the door. This releases the door lock. If the control signal from the control signal output unit 15 is a door lock, the door lock controller that receives this control signal controls the door lock mechanism to lock the door. This locks the door.

As described above, in this embodiment, in the transmission, the low frequency carrier is modulated with the key signal, the high frequency carrier is then modulated with the low frequency carrier, and the reception is received in the receiving. After passing the high-frequency signal through the bandpass filter 12, it is detected to demodulate the low-frequency signal, and the demodulated low-frequency signal is passed through the bandpass filter 61, and then detected to extract the key signal. Therefore, even if noise is received together with the desired signal due to the wide band of the bandpass filter 12, the signal after passing through the bandpass filter 12 is detected, the low frequency signal is demodulated, and then the bandpass filter 61 is again used. By passing it, noise can be removed. As a result, the reception sensitivity can be increased even if the selection accuracy of the bandpass filter 12 is low, so that even a signal with a low signal level can be extracted. As a result, it becomes possible to widen the operable range of the remote controller.

Although the door lock controller of the vehicle is controlled in the above embodiment, the engine controller for starting / stopping the engine may be controlled. Further, in the above embodiment, the invention is applied to a vehicle, but it goes without saying that it can be applied to a remote controller for electric devices such as an automatic shutter, a television and an air conditioner.

[0019]

According to the present invention, in transmission, a low frequency carrier is modulated with a key signal, then a high frequency carrier is modulated with this low frequency carrier, and the received high frequency signal is received. After passing through the first filter, it is detected to demodulate the low-frequency signal, and the demodulated low-frequency signal is passed through the second filter to detect the key signal component to extract the key signal. Therefore, even if there is noise in the signal that has passed through the first filter, noise can be effectively removed because it passes through the second filter. As a result, even if the accuracy of the first filter is low, the receiving sensitivity can be increased and even a signal with a low signal level can be taken out, so that the operable range of the remote controller can be widened.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a remote control device according to an embodiment of the present invention.

FIG. 2 is a waveform diagram showing an example of a modulation waveform by an AM modulation method of the remote control device of the embodiment.

FIG. 3 is a waveform diagram showing an example of a modulation waveform according to the FM modulation method of the remote control device of the embodiment.

FIG. 4 is a diagram showing signal processing of the remote control device according to the embodiment.

FIG. 5 is a block diagram showing a schematic configuration of a conventional remote control device.

FIG. 6 is a diagram showing signal processing of a conventional remote control device.

FIG. 7 is a diagram showing a problem in signal processing of a conventional remote control device.

FIG. 8 is a diagram showing a problem in signal processing of a conventional remote control device.

[Explanation of symbols]

 2 Key Input Section 3 Signal Generator 4 High Frequency Modulator (High Frequency Modulation Means) 5 Power Amplifier 12 Bandpass Filter (First Filter) 13 Detector (First Detection Means) 15 Control Signal Output Section 50 Transmitter (Transmission) Means) 51 low frequency modulator (low frequency modulating means) 60 receiving device (receiving means) 61 band pass filter (second filter) 62 detector (second detecting means) 63 amplifier

Claims (1)

[Claims] 1. Transmitting means for transmitting a key signal output by operating an operation key, and receiving the key signal transmitted by this transmitting means for opening / closing a vehicle door lock or starting / stopping an engine. A remote control device comprising: a receiving unit that outputs a control signal for outputting a low-frequency modulating unit that modulates a low-frequency carrier wave with a key signal; and an output of the low-frequency modulating unit. A high-frequency modulator that modulates a high-frequency carrier wave; wherein the receiver receives a first filter having a pass band that allows the high-frequency signal transmitted from the transmitter to pass, and the first filter passes through the first filter. First detection means for demodulating a low frequency signal from a high frequency signal, and a second filter having a pass band for passing a key signal component of the low frequency signal demodulated by the first detection means , Remote control device, characterized in that it comprises a second detection means for demodulating a key signal from a key signal component of the low frequency signal having passed through the second filter.