WO1999052222A1

WO1999052222A1 - Non-contact moving body identifying device

Info

Publication number: WO1999052222A1
Application number: PCT/JP1998/001572
Authority: WO
Inventors: Hirofumi Fujino; Hiroshi Ishida; Shunzi Watanabe
Original assignee: Mitsubishi Denki Kabushiki Kaisha
Priority date: 1998-04-06
Filing date: 1998-04-06
Publication date: 1999-10-14

Abstract

A non-contact moving body identifying device provided with a responder (3) which is fixed to a moving body to be identified and, at the same time, writes or reads data in or from a built-in memory by demodulating a transmitted command signal and transmits a generated response signal after modulation, and an interrogator (2) which transmits the modulated command signal to the responder (3) by using a carrier, receives the transmitted response signal, and generates demodulated data. The interrogator (2) is provided with an extraction circuit (100) which extracts the frequency component of an original signal lower than the frequency of the carrier of the response signal based on the frequency of the carrier.

Description

Description Non-contact mobile object identification device Technical field

The present invention relates to a non-contact moving object identification device for products in a factory automation line for managing products and parts or in a transport system. Background art

The non-contact mobile object identification device consists of an interrogator and a transponder, and the interrogator generates a command (command signal that becomes rewriting information in the memory of the transponder) based on a command signal from a higher-level control device. Then, the signal is modulated by a transmission circuit using a carrier wave, and after modulation, is transmitted to a transponder. The transponder is fixed to the moving object to be identified, and also demodulates the command from the interrogator and writes or reads out the data to / from the internal memory (rewriting the stored contents of the memory). A response (response signal to be sent to the interrogator) is generated based on the frequency of the transmitted wave, modulated, and transmitted to the interrogator.

The transponder extracts power and received data from the modulated wave transmitted by the interrogator, and supplies power without a built-in battery. The receiving circuit of the interrogator uses a filter circuit that removes the frequency of the carrier of the transmission signal in order to prevent erroneous reception of its own transmission signal.

However, in the conventional non-contact mobile object identification device configured as described above, the carrier frequency of the command signal from the interrogator is generated based on the frequency of the carrier wave of the response signal from the transponder. The requirements for the characteristics of the filter circuit through which signals pass are strict, and the filter circuit is complicated. There was a problem. Disclosure of the invention

The present invention has been made in order to solve the above problems, and has as its object to provide a non-contact moving object identification device capable of easily and accurately extracting a response signal from a transponder.

In order to achieve this object, the non-contact mobile object identification device according to the first aspect is fixed to a mobile object to be identified, and demodulates a transmitted command signal to write or read data to or from an internal memory. A transponder that modulates and transmits the generated response signal, transmits the command signal modulated using a carrier wave to the transponder, receives the transmitted response signal, and generates demodulated data. A non-contact mobile object identification device including an interrogator for extracting a frequency component of an original signal lower than the carrier of the response signal based on the frequency of the carrier. And a means.

The extracting means of the non-contact moving object identification device according to the second aspect comprises: a pulse generating means for generating a pulse signal substantially equal to the frequency of the carrier based on the frequency of the carrier; and a pulse generating means for generating a pulse signal based on the pulse signal of the pulse generating means. Switching means for turning on and off the response signal, differential amplifying means for amplifying a difference voltage of the response signal turned on and off by the switching means, and an output signal of the differential amplifier means And a filter means for passing a voltage in a signal frequency band.

The extracting means of the non-contact moving object identification device according to the third aspect includes: differential amplifying means for amplifying a difference voltage of a response signal from the transponder; Pulse generating means for generating, and an analog of the differential amplifying means based on a pulse signal of the pulse generating means. Sample voltage holding means for sampling the output voltage and holding the voltage; and filter means for passing a voltage in the frequency band of the original signal of the output signal of the voltage holding means. It is assumed that. The extraction means of the non-contact mobile object identification device according to the fourth aspect comprises: differential amplifying means for amplifying a difference voltage of a response signal from the transponder; phase shift means for shifting the phase of the frequency of the carrier; Multiplying means for multiplying the output signal of the differential amplifying means based on the output signal of the phase shifting means; and a frequency band of a signal obtained by shifting the phase of the frequency of the response signal among the output signals of the multiplying means. And a filter means for passing the voltage.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a block diagram showing an entire configuration of a non-contact mobile object identification device showing one embodiment of the present invention.

FIG. 2 is a connection diagram showing the extraction circuit of FIG.

FIG. 3 is a waveform chart showing waveforms at various parts in FIG.

FIG. 4 is a connection diagram of an extraction circuit showing another embodiment of the present invention. FIG. 5 is a connection diagram showing the extraction circuit of FIG.

FIG. 6 is a connection diagram of an extraction circuit showing another embodiment of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION

Next, examples of the present invention will be described as follows.

Example 1

One embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a block diagram showing the overall configuration of a non-contact moving object identification device according to the present invention. In FIGS. 1 and 2, the mobile object identification device includes a host controller 1, an interrogator 2 controlled by the host controller 1, and a responder 3. The command signal and the power of the transponder 3 are transmitted from the interrogator 2 to the transponder 3. Even if the command signal is not transmitted, an unmodulated power wave is always transmitted. The interrogator 2 includes a transmission unit, a reception unit, and an interface circuit (hereinafter, referred to as an IZF circuit). The transmission unit modulates a command signal transmitted from the host control device 1 via the IZF circuit 10. It comprises a modulation circuit 11 as a means, an amplifier 14 as an amplifying means for amplifying modulated data, and a transmission antenna circuit 19 for transmitting the output of the amplifier 14 to the transponder 1.

The receiving unit includes a receiving antenna circuit 21 for receiving the response signal of the transponder 3, and extracting means for extracting a frequency component of the original signal lower than the carrier of the response signal of the transponder 3 based on the frequency of the carrier. An extraction circuit 100, a comparison circuit 25 for converting an analog output voltage of the extraction circuit 100 into a digital voltage, and a demodulation circuit 28 for demodulating a response signal output from the comparison circuit 25 are provided. ing.

The transponder 3 includes a transmission / reception antenna circuit 31 for transmitting / receiving a transmission signal to / from the interrogator 2, a modulation / demodulation circuit 33 for demodulating an amplitude / phase modulated signal, and modulating a response signal, and a modulation / demodulation circuit. It is composed of a control circuit 35 that sends and receives signals to and from the circuit 33 and analyzes the command signal 4 and creates a response signal 5, and a memory 37 that reads and writes data using the control circuit 35. Reference numeral 30 denotes a power supply rectification circuit which rectifies the power (current) received by the antenna circuit 31 and uses the power (current) as a power supply for the transponder.

The extraction circuit 1003 generates a pulse signal as a pulse generating means for generating a pulse signal substantially equal to the frequency of the carrier wave (carrier signal) based on the frequency of the carrier wave, and outputs from the pulse generation circuit 103 A switching circuit 101 as switching means for turning on / off a response signal received by the reception antenna circuit 21 based on the pulse signal thus obtained, and a switching circuit 10 The differential amplifier circuit 105 as differential amplifier means for amplifying the difference voltage between the response signals turned on and off by the step 3, and the output signal of the differential amplifier circuit 105 And a filter circuit 107 as a filter means for passing a voltage in a frequency band.

The operation of the mobile object identification device configured as described above will be described with reference to FIG. 1 to FIG. First, the response signal is transmitted from the transponder 3 to the interrogator 2, and the reception antenna 21 receives the response signal A in which the original signal is superimposed on the carrier frequency (carrier signal C) having the waveform shown in FIG. 3 (a). Receive.

On the other hand, the pulse generator 103 outputs a pulse signal P shown in FIG. 3 (b) which is substantially equal to the frequency of the carrier based on the frequency of the carrier, and turns on the switch circuit 101 by turning on the pulse signal P. Switching off and turning on / off the received signal A, and the differential amplifier circuit 105 receives the turned on / off received signal A and differentially amplifies it as shown in Fig. 3 (c). The differential signal B is output, and the filter circuit 107 obtains an analog voltage extraction signal F substantially equal to the frequency of the original signal shown in FIG. 3 (d). Convert to

According to the above embodiment, the response signal is switched at the carrier frequency, and the original signal is differentially amplified and extracted by the filter circuit. Therefore, the response signal is not affected by the reception impairment due to the carrier frequency. Only the response signal from the device 3 can be easily detected, and the communication reliability can be improved.

Example 2.

Another embodiment of the present invention will be described with reference to FIG. FIG. 4 is a connection diagram showing a receiving unit of the interrogator. In FIG. 4, an extraction circuit 200 includes a differential amplification circuit 201 as a differential amplification means for amplifying a differential voltage of a response signal of the transponder 2 and a frequency of a carrier (carrier signal). Pulse generation means for generating a pulse signal approximately equal to the frequency of the carrier wave A circuit for sampling the voltage of the analog output signal of the differential amplifier based on the circuit and a pulse signal output from the pulse generation circuit, and holding the sampled voltage for holding the voltage It comprises a sample-and-hold circuit 205 as a means, and a filter circuit 207 as a filter means for passing a voltage in the frequency band of the original signal among the output signals of the sample-and-hold circuit 205.

The operation of the mobile object identification device configured as described above will be described with reference to FIG. 1, FIG. 4, and FIG. First, a response signal is transmitted from the transponder 3 to the interrogator 2, and the response signal A in which the original signal is superimposed on the frequency of the carrier (carrier signal) having the waveform shown in FIG. The differential amplifier circuit 105 receives the received signal A and outputs a differentially amplified differential signal B.

On the other hand, the pulse generation circuit 203 outputs the pulse signal P shown in FIG. 5 (b) which is substantially equal to the frequency of the carrier based on the frequency of the carrier, and the sample hold circuit 205 outputs the analog difference. In addition to sampling the voltage of the dynamic signal B, this voltage is held and a sample signal S shown in FIG. 5 (c) is generated. The filter circuit 207 generates the original signal shown in FIG. 3 (d). An analog extraction signal F that is approximately equal to the frequency is obtained, and converted to a digital signal by the comparison circuit 25.

Example 3.

Another embodiment of the present invention will be described with reference to FIG. FIG. 6 is a connection diagram showing a receiving unit of the interrogator. In FIG. 6, an extraction circuit 300 includes a differential amplifier circuit 301 that amplifies a difference voltage of a response signal from the transponder 3 and a phase shift unit that shifts the phase of the frequency of a carrier (carrier signal). And a multiplication circuit 30 as multiplication means for multiplying the output signal of the differential amplifier circuit 301 based on the output signal of the phase shift circuit 303. 5 and a filter circuit 307 as filter means for passing a voltage in a frequency band of a signal obtained by shifting the frequency of a response signal out of the output signal of the multiplication circuit 305.

The operation of the mobile object identification device configured as described above will be described with reference to FIG. First, a response signal is transmitted from the transponder 3 to the interrogator 2, and the response signal A in which the original signal is superimposed on the carrier frequency is received by the receiving antenna 21, and the differential amplifier circuit 105 receives the response signal a is input and outputs a voltage V _B of the differential signal B of the differential amplified following equation (1).

On the other hand, the phase shifting circuit 3 0 3 shifts the phase of the frequency of the carrier wave to generate a voltage V _Y of the shift signal Y of equation (2), the multiplication circuit 3 0 5, the differential signal B and the shift signal Multiply by Y and output the voltage V _z of the multiplication signal Z in the following equation (3).

This voltage V _z has a frequency component of the sum ω a of twice the carrier frequency ω c and the original signal frequency ω s, and the difference ω b between the frequency twice the carrier frequency ω c and the original signal frequency ω s. appear. Therefore, an angular frequency ωa is generated in a low-frequency region and an angular frequency cb is generated in a high-frequency region around a frequency twice the carrier frequency ωc. Accordingly, the filter circuit 307 outputs the component of the angular frequency ωa or ωb of the multiplied signal Z as an extraction signal F, and the analog extraction signal F is converted into a digital signal by the comparison circuit 25. Convert.

V B = V! s i η ω c t + V, s i n ω c t s i n ω s t (1)

V, c os ω c t (2)

V _z = KJ sin 2 ω ct — K ₂ {cos co at — cost} (3)

Where K ₁ = 1 Z2 V ₁ V ₃ , K ₂ = 1/4 V ₂ V ₃

co a = 2 c c + o) s, co b = 2 co c— co s

ω ct = angular frequency of carrier wave, angular frequency of ω st dual signal As described above, according to the first invention, the interrogator is provided with the extraction means for extracting the frequency component of the original signal lower than the carrier of the response signal based on the frequency of the carrier. This has the effect that the response signal can be easily and accurately extracted.

According to the second aspect, in addition to the effect of the first aspect, the extracting means includes a pulse generating means for generating a pulse signal substantially equal to the frequency of the carrier based on the frequency of the carrier, and a pulse of the pulse generating means. Switching means for turning on / off the response signal based on the signal; differential amplifying means for amplifying a difference voltage of the response signal turned on / off by the switching means; and an output signal of the differential amplifying means. Since the filter means for passing the voltage in the frequency band of the present invention is provided, there is an effect that the circuit can be simply configured. According to the third invention, in addition to the effect of the first invention, the extracting means further comprises: a differential amplifying means for amplifying a difference voltage of a response signal from the transponder; Pulse generating means for generating substantially equal pulse signals; sample voltage holding means for sampling the voltage of the analog output signal of the differential amplifying means based on the pulse signals of the pulse generating means and holding the voltage; However, since the filter means for passing the voltage in the frequency band of the original signal out of the output signal of the voltage holding means is provided, there is an effect that the circuit can be simply configured.

According to the fourth aspect, the extracting means includes: differential amplifying means for amplifying a differential voltage of the response signal from the transponder; phase shifting means for shifting the phase of the frequency of the carrier; Multiplying means for multiplying the output signal of the phase shifter based on the output signal of the phase shifter; Therefore, there is an effect that the circuit can be easily configured. Industrial applicability

As described above, the non-contact mobile object identification device according to the present invention is used for non-contact communication by the interrogator and the transponder.

Claims

The scope of the claims

1. A transponder that is fixed to the mobile object to be identified, demodulates the transmitted command signal, writes or reads data to or from the internal memory, modulates the generated response signal, and transmits it.

A non-contact mobile object identification device comprising: an interrogator that transmits the command signal modulated using a carrier wave to the transponder, receives the transmitted response signal, and generates demodulated data. hand,

Extracting means for extracting a frequency component of the original signal lower than the carrier of the response signal based on the frequency of the carrier;

A non-contact moving object identification device comprising:

2. The extraction means is as follows:

Pulse generating means for generating a pulse signal substantially equal to the frequency of the carrier based on the frequency of the carrier;

Switching means for turning on / off the response signal based on the pulse signal of the pulse generation means;

A differential amplifying means for amplifying a difference voltage of the response signal turned on / off by the switching means,

Filter means for passing a voltage in the frequency band of the original signal out of the output signal of the differential amplifying means;

The non-contact moving body according to claim 1, characterized by comprising:

3. The extraction means is

A differential amplifying means for amplifying a difference voltage of the response signal from the transponder; a pulse generating means for generating a pulse signal substantially equal to the frequency of the carrier based on the frequency of the carrier; Sample voltage holding means for sampling the analog output voltage of the differential amplifying means based on the pulse signal of the pulse generating means, and holding this voltage;

Filter means for passing a voltage in the frequency band of the original signal out of the output signal of the voltage holding means;

2. The non-contact mobile object identification device according to claim 1, comprising:

4. The extraction means

A differential amplifying means for amplifying a difference voltage of the response signal from the transponder; a phase shifting means for shifting a phase of a frequency of the carrier; and an output signal of the differential amplifying means as an output signal of the phase shifting means. Multiplication means for multiplying based on

Filter means for passing a voltage in the frequency band of a signal obtained by shifting the phase of the frequency of the response signal out of the output signal of the multiplying means;

The non-contact moving body according to claim 1, characterized by comprising: