Communication method and device of ultrasonic passive tag reader-writer

Abstract

This invention relates to a communication method and apparatus for an ultrasonic passive tag reader / writer. It employs a single ultrasonic transducer for simultaneous energy and information transmission, adaptively adapts to communication duration, and uses time-division multiplexing to encode the transmitted signal. First, initially, the reader / writer drives the ultrasonic transducer to emit an ultrasonic signal to the passive tag for a specified period. Once the passive tag is fully charged, it responds. The reader / writer records this charging time and uses it as a reference for the next communication step. Second, by designing an encoding method with stronger error correction capabilities, the accuracy is improved. This invention effectively saves communication energy consumption, is applicable to ultrasonic communication at any frequency, enhances its applicability, and improves transmission efficiency and accuracy. It is suitable for ultrasonic passive tag communication using a single ultrasonic transducer, and the method is simple with stable and reliable data transmission.

Description

Technical Field

[0001] This invention relates to the field of ultrasonic passive tag technology, and in particular to a communication method and device for an ultrasonic passive tag reader / writer. Background Technology

[0002] The Internet of Things (IoT) industry is developing rapidly, and ID (Identity Document) technology is a crucial factor driving this development. Currently, active tags on the market rely on batteries or other external power sources for their lifespan. Frequent battery replacements and charging lead to instability and inconvenience during use, severely limiting their application scenarios.

[0003] In this context, passive tags are gaining increasing attention. Currently, the vast majority of passive tags on the market are based on radio frequency identification (RFID) technology, which is widely used in access control systems, public transportation systems, banking systems, etc. However, they are easily interfered with by metal devices, which reduces transmission reliability. In particular, they can hardly work properly when attached to metal surfaces.

[0004] In response, some existing technologies disclose communication methods for ultrasonic-based passive tag readers; however, existing ultrasonic-based passive tag communication methods generally have the following drawbacks:

[0005] 1. The transmission and reception of ultrasonic signals require higher precision.

[0006] 2. It places higher demands on the power consumption of the equipment and cannot effectively save communication energy. Summary of the Invention

[0007] The purpose of this invention is to provide a communication method and device for an ultrasonic passive tag reader / writer. It can realize the transmission of energy and information using a single ultrasonic transducer, which can effectively save hardware costs. Furthermore, it uses time-division multiplexing to encode data, which has strong error correction capabilities and is simple and clear. At the same time, decoding is simple and does not consume too many computing resources.

[0008] The objective of this invention can be achieved through the following technical solutions:

[0009] A communication method for an ultrasonic passive tag reader includes:

[0010] Send a charging signal and wait for feedback, wherein the charging signal is configured as an uninterrupted ultrasonic signal for a first set duration;

[0011] If a feedback response signal is received within the pre-configured waiting time, an identification command or a writing command is sent. The identification command or writing command is composed of multiple first signal units and / or second signal units. The first signal unit includes an uninterrupted ultrasonic signal lasting for a second set duration and an empty signal lasting for a second duration. The second signal unit includes an uninterrupted ultrasonic signal lasting for a third set duration, where the third set duration is twice the second set duration.

[0012] After sending the identification command, one or more data strings are received, wherein the data strings are composed of multiple first signal units and / or second signal units, and each data string is separated by a null signal that lasts for a fourth set duration.

[0013] After sending the write command, one or more data strings are sent, wherein the data strings are composed of multiple first signal units and / or second signal units, and each data string is separated by an empty signal that lasts for a fourth set duration.

[0014] The fourth set duration is greater than twice the second set duration.

[0015] The process of sending a charging signal and waiting for feedback specifically includes:

[0016] Initialize the counter value N to 1;

[0017] A charging signal is sent with N*k as the first set duration, where k is the unit duration;

[0018] If no feedback response signal is received within the pre-configured waiting time, the count value N is incremented by 1, and after resetting the first set duration, a charging signal is sent.

[0019] The step of sending a charging signal and waiting for feedback also includes:

[0020] If a feedback response signal is received within the pre-configured waiting time, the count value N is saved as the current value.

[0021] A communication method for an ultrasonic passive tag reader includes:

[0022] The system receives a charging signal and sends a feedback response signal after charging is completed. The feedback response signal is composed of multiple first signal units and / or second signal units. The first signal unit includes an uninterrupted ultrasonic signal lasting for a second set duration and an empty signal lasting for a second duration. The second signal unit includes an uninterrupted ultrasonic signal lasting for a third set duration, where the third set duration is twice the second set duration.

[0023] Upon receiving the identification instruction, the data stored in the memory is sent out as one or more data strings, wherein the data strings are composed of multiple first signal units and / or second signal units, and each data string is separated by a blank signal that lasts for a fourth set duration.

[0024] Upon receiving a write command, one or more data strings are received and written into the memory, wherein the data strings are composed of multiple first signal units and / or second signal units, and each data string is separated by a null signal that lasts for a fourth set duration.

[0025] The method further includes:

[0026] After all data is written into the memory, a check code signal is sent, which is composed of multiple first signal units and / or second signal units.

[0027] A communication device for an ultrasonic passive tag reader / writer includes:

[0028] An ultrasonic transducer generates ultrasonic signals based on electrical energy and converts ultrasonic waves into electrical signals.

[0029] The charging transmission unit is configured to: send a charging signal and wait for feedback, wherein the charging signal is configured to be an uninterrupted ultrasonic signal that lasts for a first set duration;

[0030] The instruction sending unit is configured to: if a feedback response signal is received within a pre-configured waiting time, send an identification instruction or a writing instruction, wherein the sending identification instruction or writing instruction is composed of a combination of multiple first signal units and / or second signal units, the first signal unit includes an uninterrupted ultrasonic signal lasting for a second set duration and an empty signal lasting for a second duration, and the second signal unit includes an uninterrupted ultrasonic signal lasting for a third set duration, wherein the third set duration is twice the second set duration;

[0031] The data reading unit is configured to receive one or more data strings after sending an identification command, wherein the data strings are composed of multiple first signal units and / or second signal units, and each data string is spaced by a null signal that lasts for a fourth predetermined duration.

[0032] The first data transmission unit is configured to: after sending a write instruction, send one or more data strings thereafter, wherein the data strings are composed of multiple first signal units and / or second signal units, and each data string is separated by an empty signal that lasts for a fourth predetermined duration.

[0033] The fourth set duration is greater than twice the second set duration.

[0034] The charging and transmitting unit includes:

[0035] The count value initialization subunit is configured to initialize the count value N to 1.

[0036] The charging control subunit is configured to send a charging signal with a first set duration of N*k, where k is the unit duration.

[0037] The iterative control subunit is configured to: if no feedback response signal is received within the pre-configured waiting time, increment the count value N by 1, and after resetting the first set duration, send a charging signal.

[0038] The charging and transmitting unit includes:

[0039] The count value storage subunit is configured to save the count value N as the current value if a feedback response signal is received within a pre-configured waiting time.

[0040] A communication device for an ultrasonic passive tag reader / writer includes:

[0041] An ultrasonic transducer generates ultrasonic signals based on electrical energy and converts ultrasonic waves into electrical signals.

[0042] A charging feedback unit is configured to receive a charging signal and send a feedback response signal after charging is completed. The feedback response signal is composed of a plurality of first signal units and / or second signal units. The first signal unit includes an uninterrupted ultrasonic signal lasting for a second set duration and an empty signal lasting for a second duration. The second signal unit includes an uninterrupted ultrasonic signal lasting for a third set duration, wherein the third set duration is twice the second set duration.

[0043] The second data transmission unit is configured to: after receiving the transmission identification instruction, transmit the data stored in the memory to the outside in the form of one or more data strings, wherein the data strings are composed of multiple first signal units and / or second signal units, and each data string is separated by a continuous empty signal for a fourth set duration.

[0044] The data writing unit is configured to: receive one or more data strings after receiving a write instruction, and write them into the memory, wherein the data strings are composed of multiple first signal units and / or second signal units, and each data string is separated by a null signal that lasts for a fourth set duration.

[0045] The device further includes:

[0046] The verification sending unit is configured to send a verification code signal after all data has been written into the memory. The verification code signal is composed of multiple first signal units and / or second signal units.

[0047] Compared with the prior art, the present invention has the following beneficial effects:

[0048] 1. Energy and information transmission can be achieved using a single ultrasonic transducer, which can effectively save hardware costs. Furthermore, the time-division multiplexing method is used for data encoding, which has strong error correction capabilities and is simple and clear. At the same time, decoding is simple and does not consume too many computing resources.

[0049] 2. It can adapt the charging time to different tags, communication distances or environments, thus saving communication energy consumption. Attached Figure Description

[0050] Figure 1 This is a schematic diagram of the charging waveform during the communication process of the present invention;

[0051] Figure 2 This is a schematic diagram illustrating the encoding of data "0" during the communication process of this invention;

[0052] Figure 3 This is a schematic diagram illustrating the encoding of data "1" during the communication process of this invention;

[0053] Figure 4 This is a schematic diagram of the interval signal between each data string during the data transmission and reception process in the communication process of this invention;

[0054] Figure 5 This is a flowchart illustrating the process of obtaining adaptive charging time in this invention.

[0055] Figure 6 A schematic diagram illustrating the process of a reader reading information stored in a passive tag;

[0056] Figure 7 A schematic diagram illustrating the process of a reader writing information into a passive tag;

[0057] Figure 8 A schematic diagram illustrating the hardware implementation of this application;

[0058] Among them: 1. Reader / writer, 2. Passive tag. Detailed Implementation

[0059] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0060] This application utilizes time-division multiplexing to achieve charging, communication, and data encoding functions. The reader / writer employs ultrasonic communication to realize reading and writing operations on passive tags. An ultrasonic transducer is used as the energy and information transmission device, and time-division multiplexing is used to simultaneously perform charging and communication encoding.

[0061] In the process of passive tag communication based on ultrasound, the passive tag needs to be charged first, and then the relevant data reading and writing operations are performed after the charging is completed.

[0062] In this embodiment, the following is determined first:

[0063] 1. The unit of duration k is milliseconds. Similarly, the units of the first set duration, the second set duration, the third set duration, and the fourth set duration are all milliseconds.

[0064] 2. The first signal unit represents the data "0", and the second signal unit represents the data "1".

[0065] 3. The length of the instruction is limited to the length of a data string in this embodiment, and the length of a data string is 8 bits.

[0066] Based on such Figure 8 The reader and passive tag shown in the diagram first have the reader emit a charging pulse signal for a duration of k milliseconds via an ultrasonic transducer. After the passive tag is fully charged, it responds. The reader records this charging time (N*k) milliseconds, storing the count value N. Using this charging time as a reference time, the reader then emits a pulse signal for a duration of m = N*k milliseconds. Figure 1 The charging pulse signal shown;

[0067] Then, the reader encodes the data to be sent, specifically using the following encoding method:

[0068] like Figure 2 As shown, an ultrasound signal of n milliseconds plus no signal of n milliseconds represents the data "0";

[0069] like Figure 3 As shown, a 2n-millisecond ultrasound signal represents data "1";

[0070] like Figure 4 As shown, j milliseconds of no signal represents the interval between data strings;

[0071] Where m>2n and j>2n, based on this, a j-millisecond period without signal can be used as an interval and a means of correction to correct the transmitted data.

[0072] In addition, in this embodiment, a signal representing the end of communication can also be designed, which can be a no-signal with a length greater than j.

[0073] The encoded information is transmitted to the passive tag via an ultrasonic transducer. The passive tag receives the signal and decodes it via the ultrasonic transducer. After successful identification, it sends the information stored in the tag to the reader or writes the data sent by the reader into the passive tag's memory.

[0074] The process by which the reader obtains the adaptive charging time is as follows: Figure 5 The specific process is as follows:

[0075] 1. The reader's counter value N is initially 0;

[0076] 2. Increment the counter value by 1. The reader sends a charging signal of k milliseconds. Within the specified time T, the passive tag responds. After receiving the response signal, the reader records the current value of N. At this time, the time N*k milliseconds is used as the charging time for the next communication. If the reader does not receive a response, it will re-execute the step after a delay of t0.

[0077] Of course, in other embodiments, a simpler approach can also be adopted, as follows:

[0078] 1. The reader's counter value N is initially set to 1;

[0079] 2. The reader sends a charging signal of k milliseconds. Within a specified time T, the passive tag responds. After receiving the response signal, the reader records the current value of N. At this time, the time N*k milliseconds is used as the charging time for the next communication. If the reader does not receive a response, the count value is incremented by 1, and the step is repeated after a delay of t0.

[0080] The read operation process of the reader / writer, such as Figure 6 The specific process is as follows:

[0081] 1. The reader sends a charging signal to the passive tag. Within a specified time T, the passive tag responds with a signal. If the reader does not receive a response, it repeats this step after a delay of t0.

[0082] 2. The reader sends an identification command signal to the passive tag. Within a specified time T, the passive tag identifies the command and replies with stored information to the reader. If the reader does not reply with a stored signal, it will re-execute the previous step after a delay of t0.

[0083] The write operation process of the reader, such as Figure 7 The specific process is as follows:

[0084] 1. The reader sends a charging signal to the passive tag. Within a specified time T, the passive tag responds with a signal. If the reader does not receive a response, it delays for t0 and then repeats this step; otherwise, it proceeds to the next step.

[0085] 2. The reader sends a write command to the passive tag. Within a specified time T, the passive tag recognizes the command and sends an acknowledgment signal. If the reader does not receive an acknowledgment, it will delay for t0 and then re-execute the previous step; otherwise, it will execute the next step.

[0086] 3. The reader sends write data to the passive tag. Within a specified time T, the passive tag recognizes the instruction, stores the received data in its memory, and replies with a verification code to the reader. If the reader does not receive the verification information or the verification information is incorrect, it will re-execute the first step after a delay of t0.

[0087] In this embodiment, the frequency of the ultrasonic signal can be selected as needed, but the frequencies of the ultrasonic waves generated and received by the super-powered transducer between the reader and the passive tag should be matched.

Claims

1. A communication method for an ultrasonic passive tag reader / writer, characterized in that, include: Send a charging signal and wait for feedback, wherein the charging signal is configured as an uninterrupted ultrasonic signal for a first set duration; If a feedback response signal is received within the pre-configured waiting time, an identification command or a writing command is sent. The identification command or writing command is composed of multiple first signal units and / or second signal units. The first signal unit includes an uninterrupted ultrasonic signal lasting for a second set duration and an empty signal lasting for a second duration. The second signal unit includes an uninterrupted ultrasonic signal lasting for a third set duration, where the third set duration is twice the second set duration. After sending the identification command, one or more data strings are received, wherein the data strings are composed of multiple first signal units and / or second signal units, and each data string is separated by a null signal that lasts for a fourth set duration. After sending the write command, one or more data strings are sent, wherein the data strings are composed of multiple first signal units and / or second signal units, and each data string is separated by an empty signal that lasts for a fourth set duration. The fourth set duration is greater than twice the second set duration; The process of sending a charging signal and waiting for feedback specifically includes: Initialize the counter value N to 1; A charging signal is sent with N*k as the first set duration, where k is the unit duration; If no feedback response signal is received within the pre-configured waiting time, the count value N is incremented by 1, and after resetting the first set duration, a charging signal is sent. If a feedback response signal is received within the pre-configured waiting time, the count value N is saved as the current value, and the first set duration obtained by N*k is used as the charging time for the next communication.

2. A communication device for an ultrasonic passive tag reader / writer, characterized in that, include: An ultrasonic transducer generates ultrasonic signals based on electrical energy and converts ultrasonic waves into electrical signals. The charging transmission unit is configured to: send a charging signal and wait for feedback, wherein the charging signal is configured to be an uninterrupted ultrasonic signal that lasts for a first set duration; The instruction sending unit is configured to: if a feedback response signal is received within a pre-configured waiting time, send an identification instruction or a writing instruction, wherein the sending identification instruction or writing instruction is composed of a combination of multiple first signal units and / or second signal units, the first signal unit includes an uninterrupted ultrasonic signal lasting for a second set duration and an empty signal lasting for a second duration, and the second signal unit includes an uninterrupted ultrasonic signal lasting for a third set duration, wherein the third set duration is twice the second set duration; The data reading unit is configured to receive one or more data strings after sending an identification command, wherein the data strings are composed of multiple first signal units and / or second signal units, and each data string is spaced by a null signal that lasts for a fourth predetermined duration. The first data transmission unit is configured to: after sending a write instruction, send one or more data strings thereafter, wherein the data strings are composed of multiple first signal units and / or second signal units, and each data string is separated by an empty signal that lasts for a fourth predetermined duration. The fourth set duration is greater than twice the second set duration; The charging and transmitting unit includes: The count value initialization subunit is configured to initialize the count value N to 1. The charging control subunit is configured to send a charging signal with a first set duration of N*k, where k is the unit duration. The iterative control subunit is configured to: if no feedback response signal is received within the pre-configured waiting time, increment the count value N by 1, and after resetting the first set duration, send a charging signal; The counting value storage subunit is configured to: if a feedback response signal is received within a pre-configured waiting time, save the counting value N as the current value, and use the first set duration obtained by N*k as the charging time for the next communication.

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