KR20100039998A - A tpms system being improved a wireless transmitting/receiving property - Google Patents

Abstract

PURPOSE: A TPMS(Tire Pressure Measuring System) with enhanced wireless transceiving performance is provided to improve wireless transceiving performance by adding an EOM(End Of Message) which applies other coding scheme. CONSTITUTION: TPMS sensors(10) add an EOM processed by a second coding scheme in order to inform completion time of data to tire pressure data processed by a first coding scheme. A TPMS receiver receives the data through wireless communications method, processes the data through the first coding scheme, and processes the EOM through the second coding scheme by controlling clock timing. The EOM is added by forcibly implementing logic low and high signal in the wireless communications chip of the TPMS sensors.

Description

TPMS system with improved wireless transmission and reception performance {A TPMS SYSTEM BEING IMPROVED A WIRELESS TRANSMITTING / RECEIVING PROPERTY}

This document relates to a TPMS system, and more particularly, to a TPMS system with improved wireless transmit / receive performance.

The TPMS (Tire Pressure Measuring System) system is a system that receives the tire pressure data sent from the TPMS sensor on the wheel and receives the radio from the receiver, and alerts the driver according to the wheel pressure information after processing. The application of TPMS technology to mass production vehicles is expanding, and in North America, the application of TPMS system is required by law. In such a TPMS system, the wireless communication part of how well data can be transmitted and received can be said to be a key technical matter. In the TPMS development, if the wireless transmission / reception performance is lower than the standard, the error of the tire warning light will be probabilistic, which causes confusion for the driver. In addition, in North America, there are additional problems in which legal and quality issues arise.

This document provides a TPMS system with improved wireless transmit / receive performance by adding an end-of-message to which a coding scheme different from that of basic data is applied in the background art.

The TPMS system having improved wireless transmission / reception performance as one means for solving the above-mentioned problems is an end processed by a second coding scheme to inform the tire pressure data of the vehicle processed by the first coding scheme to inform the completion time of the data. It includes an TPMS sensor that transmits data, to which an object message is added.

The TPMS system having improved wireless transmission / reception performance may receive the data from the TPMS sensor in a wireless communication manner, process the data in the first coding scheme, and then adjust a clock timing to adjust the end-of-message with the second coding scheme. It includes a TPMS receiver to process.

The end of message may be added by forcibly implementing a logic low signal and a logic high signal in a wireless communication chip of the TPMS sensor.

The data includes a checksum, and the checksum may be compared to process the end-of-message with the second coding scheme when there is an error in data reception.

The first coding scheme may be a Manchester coding scheme and the second coding scheme may be a frequency shift keying (FSK).

At this time, the end-of-message is added by forcibly implementing a continuous logic low signal and a continuous logic high signal in a wireless communication chip of the TPMS sensor, and the clock timing is changed between the logic low signal and the logic high signal. It can be adjusted to handle.

The TPMS receiver may reprocess the data according to the processing result of the end of message.

According to the present invention, an end-of-message is added in a unit such as a TPMS system using in-vehicle RF wireless communication, thereby improving the accuracy and reliability of the message.

In addition, it is possible to implement an end-of-message that is processed by a coding method different from basic data using one wireless communication chip.

In addition, through a plurality of reset operations for a wireless communication chip for a predetermined time before data transmission, it is possible to simultaneously implement Manchester coding and simulated FSK coding using one wireless communication chip.

In addition, after processing according to the Manchester coding scheme after data reception, the clock timing of the wireless communication chip is adjusted to decode the end-of message according to the simulated FSK coding scheme.

Hereinafter, embodiments of the present invention for a TPMS system having improved wireless transmission / reception performance by adding an end-of message to which a coding scheme different from basic data is applied will be described in detail with reference to the accompanying drawings.

1 is a diagram illustrating a configuration of a TPMS system to which an improved wireless transmission / reception scheme according to an embodiment of the present invention may be applied.

The TPMS system shown in FIG. 1 includes a TPMS sensor 10 mounted on four tires T, a TPMS receiver 20 for receiving sensor information transmitted from the TPMS sensor 10, and sensor information. And a display 30 for providing a tire condition to the driver. In this case, the TPMS sensor 10 codes the TPMS message including the sensor information, that is, data about the tire pressure, according to a predetermined coding scheme, and then transmits the data through a wireless communication scheme. Then, the TPMS receiver 20 receives the TPMS message and decodes it according to the coding scheme applied by the transmitting TPMS sensor 10 to extract sensor information. Then, the sensor information is checked and analyzed to inform the driver of the tire state through the display 30.

When the TPMS sensor 10 transmits a TPMS message in a wireless communication scheme, data is transmitted over the air by implementing a digital signal of 0 and 1 using a center frequency component. In this case, various modulation schemes, such as non-return-to-zero (NRZ), Manchester, amplitude-shift keying (ASK), and frequency-shift keying (FSK), are used according to the frequency modulation scheme. In the case of a TPMS system, the frequency coding is performed in a manner that guarantees the maximum message transmission in consideration of a malicious vehicle environment in which there is a high risk of message loss. Manchester coding may be used.

In the following description, an embodiment of the present invention will be described on the assumption that the Manchester coding method is used as the basic coding method in the TPMS system. However, the present invention is not limited thereto.

2 is a diagram for describing a Manchester coding scheme that may be used as a basic coding scheme in a TPMS system having improved wireless transmission / reception performance according to an embodiment of the present invention.

According to a general frequency shifting coding scheme, as shown in FIG. 2, a deviation of the center frequency 200 by d is set so that, for example, the low frequency (= center frequency-d, 210) is zero. By processing the digital signal of and processing the high frequency (= center frequency + d, 220) into a digital signal of 1, logic is implemented to show the characteristics vulnerable to DC noise.

However, according to the Manchester coding scheme, as shown in FIG. 2, the deviation is given by the center frequency 200 as much as d, for example, from the low frequency 210 to the high frequency 220. The logic is implemented by processing a digital signal of zero when a frequency shift occurs and processing a digital signal of one when a frequency shift occurs from a high frequency 220 to a low frequency 210.

When coding using the Manchester coding scheme, DC noise is removed to enable data transmission that is resistant to DC noise. The Manchester coding scheme is used in various units as a transmission scheme to secure reception performance, which is an important characteristic of a vehicle wireless communication.

Processing data according to the Manchester coding scheme has the advantage of being strong against DC noise and preventing logic from error due to transient noise, as described above. In case of occurrence or frequency shift due to the medium, an error occurs due to missing data. In addition, in applying the noise filtering technique, since the length and bit time of the data are processed as fixed variables, it is difficult to process the filter.

Therefore, in order to improve the TPMS reception performance, further improvement of a data processing technique capable of overcoming a bad condition of a vehicle, such as noise generated depending on wiring, a vehicle shape, a tire wheel shape, and the surrounding electrical equipment, is required.

3 is a diagram for describing a method of improving wireless transmission / reception performance in a TPMS system using a Manchester coding scheme according to an embodiment of the present invention.

According to the present embodiment, an end of message (EOM) 310 indicating an end point of data is added to basic TPMS data 300 to which Manchester coding scheme is applied, but wirelessly vulnerable to AC noise of Manchester coding. In order to improve the transmission / reception performance, the wireless transmission / reception performance of the TPMS system is improved by adding an end-of-message 310 to which a coding scheme different from the basic data is applied.

In general, since a wireless communication IC chip implemented in a TPMS sensor and performing a wireless communication function is uniquely determined according to a coding method, it is difficult to apply another coding method together with one coding method. That is, when using a dedicated wireless communication chip that processes the basic data by the Manchester coding scheme, it is difficult to simultaneously use other coding schemes because only the edge, that is, frequency shift, is monitored according to the Manchester coding scheme.

Therefore, in order to process data by applying two coding schemes according to the present embodiment, two chips corresponding to each chip may be embedded at the same time. However, since there is a problem of an increase in parts and a corresponding cost increase, the following describes a method of processing data by applying two coding schemes using a single wireless communication chip.

4 is a diagram for describing a method of improving wireless transmission / reception performance using one wireless communication chip in a TPMS system using a Manchester coding scheme based on an embodiment of the present invention.

According to the present embodiment, the end-of-message 400 informing the completion time of the data to the basic TPMS data to which the Manchester coding scheme is applied and applying a coding scheme different from the above basic data is added, but the Manchester coding scheme and the end-of-message ( The other coding scheme applied to 400 is implemented through one wireless communication chip implemented in the TPMS sensor, thereby improving the wireless transmission / reception performance of the TPMS system.

According to the present embodiment, the logic chip of the TPMS sensor generates a logic low signal and a logic high signal for a predetermined time to implement the end-of-message 400, and the clock timing of the TPMS receiver side. By adjusting the to process the received data to be able to decode the end-of-message (400).

First, the operation of the TPMS sensor side will be described. When using a wireless communication chip that processes data according to Manchester coding method, data can not be maintained for a certain time because only the edge is monitored, so that a logic low signal and a logic high signal can be It is basically impossible to generate.

Therefore, in order to implement this, in the present embodiment, after the transmission of the basic TPMS data 420 is completed, the TPMS sensor adds the end-of-message 400 as a tag. In order to simulate a coding scheme other than the conventional coding scheme, this operation is performed several times by resetting the reset switches 420 and 430 which are set to logic low or logic high in a wireless communication chip implemented in a TPMS sensor. Generate a signal.

In this case, when the frequency-shift keying (FSK) coding scheme is used as the coding scheme applied to the end-of-message 400, after the transmission of the basic TPMS data 420 is completed, for example, four low reset switch operations are performed. This generates a logic low signal that is held for a period of time, corresponding to four bits. Then, the FSK coding scheme can be simulated by generating a logic high signal that is maintained for a predetermined time corresponding to 4 bits through four high reset switch operations.

That is, according to the present exemplary embodiment, the end of message 400 inserts a function added by the wireless communication chip instead of the microcomputer in the sensor to implement data. In order to implement the end-of-message 400 in the above manner, in order to apply the FSK logic processing technique, the FSK processing scheme is transmitted through a reset setting command of the wireless communication chip rather than sending data using the Manchester coding scheme. It will be copied.

First, the operation of the TPMS receiver side will be described. If the TPMS sensor sends the end-of-message 400 to the basic TPMS message, the TPMS receiver must apply logic that can process not only the basic TPMS message but also the end-of-message 400. As described above, since the wireless communication chip processes data using only one method, logic for processing the end-of-message 400 simulating FSK data using the Manchester coding method should be added to the TPMS receiver.

On the TPMS receiver side, the received data is first switched to the end-of-message 400 processing mode in which Manchester data is read. In this case, if the check sum bit is included in the basic data, after the error checking operation is completed accordingly, the process changes to the end-of-message 400 processing mode. In addition, when it is determined that the data is normally received as a result of the error check, the data processing may be immediately completed without processing the end-of-message 400 according to the present embodiment.

In order to determine the start and end of data processing, a clock promised between the transmitter and the receiver is used. If the timing set to the clock does not match, data loss occurs. That is, according to the wireless communication chip according to the present embodiment, since the Manchester coding scheme is basically applied, if an edge is not detected within the reference time, it is determined that there is an error.

Accordingly, in order to process the end-of-message 400 according to the present exemplary embodiment without error using an existing wireless communication chip, clock timing is adjusted at the end of Manchester coding. For example, the end-of-message 400 which consists of a logic low signal maintained for a predetermined time corresponding to 4 bits and a logic high signal maintained for a predetermined time corresponding to 4 bits by simulating the FSK coding scheme at the TPMS sensor side. Assume that it is sent.

In this case, the TPMS receiver temporarily increases the processing time by doubling the clock timing constants that process the data. Then, the end-of-message 400 determines the data reception suitability by processing an edge signal that transitions from logic low to logic high after the clock timing increased by four times. This can be thought of as processing data by slowing down the data bits by four times. Therefore, it is not only robust against the noise coming in the middle, but also an error can be prevented by determining the completion time of the data.

5 is a flowchart illustrating a method of improving wireless transmission / reception performance using one wireless communication chip in a TPMS system using a Manchester coding scheme based on an embodiment of the present invention.

FIG. 5 illustrates the operation of the TPMS receiver in particular. First, in step S500, data including an end-of-message processed by the FSK coding scheme and the basic TPMS data processed by the Manchester coding scheme are received.

Then, the data once received in step S510 is decoded according to the Manchester coding scheme which is a basic coding scheme, and the data is processed in step S520. In operation S530, whether an error occurs may be determined using the checksum bit included in the data.

If there is an error in the data reception only to check the end-of-message according to the present embodiment, the end-of-message may be confirmed by checking whether the data is normally received in step S540 and proceeding to step S541.

In step S541, the end-of-message is detected and the FSK coding mode simulated in step S542 is switched to adjust the decoding clock timing of the TPMS receiver in step S543. In addition, by detecting a logic edge according to the clock timing changed in step S544, the end-of message may be confirmed, and thus, the completion point of data may be recovered in step S545.

Then, in step S546, the data may be reprocessed with reference to the recovered data completion time point, and thereafter, in step S547, it may be determined whether an error has occurred using the checksum bit again. In step S550, the data decoding is terminated. In step S560, the data processing result is transmitted to the microcomputer in the TPMS receiver to terminate the process.

Although described above with reference to the drawings and embodiments, those skilled in the art that the present invention can be variously modified and changed within the scope without departing from the spirit of the invention described in the claims below I can understand.

1 is a diagram illustrating a configuration of a TPMS system to which an improved wireless transmission / reception scheme according to an embodiment of the present invention may be applied.

2 is a diagram for describing a Manchester coding scheme that may be used as a basic coding scheme in a TPMS system having improved wireless transmission / reception performance according to an embodiment of the present invention.

3 is a diagram for describing a method of improving wireless transmission / reception performance in a TPMS system using a Manchester coding scheme according to an embodiment of the present invention.

4 is a diagram for describing a method of improving wireless transmission / reception performance using one wireless communication chip in a TPMS system using a Manchester coding scheme based on an embodiment of the present invention.

5 is a flowchart illustrating a method of improving wireless transmission / reception performance using one wireless communication chip in a TPMS system using a Manchester coding scheme based on an embodiment of the present invention.

<Description of the code for the main configuration of the drawings>

10: TPMS sensor 20: TPMS receiver

300: TPMS message 310, 400: End of message

Claims (6)

A TPMS sensor that transmits data to the tire pressure data of the vehicle processed by the first coding scheme, to which an end-of message processed by the second coding scheme is added to indicate when the data is completed; And A TPMS receiver receiving the data in a wireless communication method and processing the first coding method, and then adjusting a clock timing to process the end-of message using the second coding method. Including, TPMS system with improved wireless transmission and reception performance. The method according to claim 1, And the end-of-message is added by forcibly implementing a logic low signal and a logic high signal in a wireless communication chip of the TPMS sensor. The method according to claim 1, And the data includes a checksum, and compares the checksums to process the end-of-message with the second coding scheme when there is an error in data reception. The method according to claim 1, The first coding scheme is a Manchester coding scheme and the second coding scheme is Frequency-Shift Keying (FSK). The method according to claim 4, The end of message is added by forcibly implementing a continuous logic low signal and a continuous logic high signal in a wireless communication chip of the TPMS sensor, and the clock timing handles the change between the logic low signal and the logic high signal. TPMS system, characterized in that the radio transmission and reception performance is improved. The method according to claim 3, The TPMS receiver, characterized in that for reprocessing the data according to the end-of-message processing result, TPMS wireless transmission and reception performance improved TPMS system.

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