JP2006160189A - Tire information management system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tire information management system capable of enhancing the data receiving probability of between a sensor module and a reception module and transmitting and receiving the measuring data without changing the system even when the reception module goes in failure. <P>SOLUTION: The reception module 1 is equipped with a receiving signal intensity measuring means 12 and measures the receiving signal intensity of the data signal given from the sensor module 3. A central control module 5 compares the receiving signal intensity value of the data signal given from an antenna 2 measured by the reception module 1 by each sensor module 3, selects a reception module 1 corresponding to the antenna which gives the maximum receiving signal intensity among the reception modules able to transmit and receive the data, and requests a data acquisition from the sensor module 3. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a plurality of sensor modules that are mounted on a tire and that detects the state of the tire including the tire internal pressure, a receiving module that acquires data from these sensor modules, and commands the receiving module to acquire data from the sensor module And a central control module for the tire information management system.

  To manage the tires of vehicles in operation, such as construction vehicles, a sensor module that measures tire temperature and pressure is attached to the inner surface of the tire, and wireless signals including measurement data transmitted from this sensor module are received. The module receives this signal and sends this signal to the vehicle operation management center that manages multiple vehicles. In the event of a dangerous situation, the vehicle operation management center instructs the driver on appropriate measures. A tire information management system has been proposed (for example, Patent Document 1).

In this system, a receiving module corresponding to each sensor module mounted in each tire is attached to the vehicle, and signals processed by this receiving module are once collected in the central control module of this vehicle. The central control module transmits a radio wave to the vehicle operation management center.
JP-A-10-104103

  In the conventional tire information management system described above, each receiving module is arranged in the vicinity of the sensor module of each tire, and the signal transmitted from the sensor module is generally closest to the sensor module. In order to show a large received signal strength, this sensor module and the nearest receiving module are fixedly associated with each other, and data is transmitted and received between these modules. There are structures such as mufflers, and these structures disturb the traveling direction of radio waves. Therefore, the received signal strength is not always the highest when combined with the receiving module closest to the sensor module, and data reception is often performed. There were cases where it was impossible.

  In addition, when the sensor module and the receiving module are fixedly associated with each other, when the number of receiving modules changes depending on the vehicle size or when communication with the sensor module becomes impossible due to a failure, the receiving module is re-established. A system change work for associating is required, and this work takes a lot of time, leading to an increase in cost.

  The present invention has been made in view of such problems, and the object thereof is to increase the data reception probability between the sensor module and the receiving module, and the number of receiving modules mounted varies depending on the vehicle size. It is an object to provide a tire information management system that can transmit and receive measurement data without changing the system even when the reception module fails.

  The present invention includes a sensor module mounted in each tire, an antenna that receives data from these sensor modules, a receiving module that is connected to the antenna and acquires data from the sensor module, and a sensor module in the receiving module. In a tire information management system comprising a central control module that commands acquisition of data from the receiving module, the receiving module comprises received signal strength measuring means for measuring the received signal strength of the data signal transmitted from the sensor module received by the antenna The central control module includes reception signal strength acquisition control means for acquiring reception signal strengths for all combinations of sensor modules and antennas, and reception signals of data signals from the antennas measured by each reception module for each sensor module. Signal strength representing strength A signal strength table creation means for creating and storing a table, and referring to the signal strength table, the received signal strength value of the data signal from the antenna is compared for each sensor module, and the data signal can be transmitted and received. And a data acquisition request means for selecting an antenna arranged at a position where the maximum received signal strength is obtained and requesting the reception module corresponding thereto to acquire data from the sensor module.

  The receiving module is preferably integrated with the central control module, and the central control module has a receiving module disposed therein, and antenna switching means is disposed between the receiving module and the antenna, and the antenna. It is preferable to connect the receiving module and the antenna by switching the switching means.

  According to the tire information management system of the present invention, a reception module corresponding to an antenna disposed at a place where the reception signal strength is the highest among the reception modules capable of measuring the reception signal strength and transmitting and receiving data to and from the sensor module. Since data transmission / reception is used, the data reception probability can be improved.

  In addition, since data is transmitted and received using a receiving module corresponding to an antenna arranged in a place where the received signal strength is the largest among the receiving modules capable of transmitting and receiving data to and from the sensor module at a fixed period, Even if the receiving module fails or the number of receiving modules is changed, the central control module can be shared without changing the system, and the cost can be reduced.

  Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a tire information management system of the present invention. In FIG. 1, a tire information management system 10 includes sensor modules 3 (SM1 to SM6) mounted in respective tires 4 of a vehicle 6, and temperature and pressure data from the sensor modules 3 (SM1 to SM6). An antenna that receives radio signals, a receiving module 1 (RM1 to RM4) that is connected to the antenna and acquires data from the sensor modules 3 (SM1 to SM6), and a central control module that collects signals from each receiving module 1 5 and a vehicle operation management center 7 that receives a signal transmitted wirelessly from the central control module 5 and monitors the running state of the tire.

  The central control module 5 is connected to the receiving module 1 (RM1 to RM4). In addition, a reception module 1 (RM1) and an antenna 2 connected to the reception module 1 (RM1) are disposed in the vicinity of the sensor module 3 (SM1), and the reception module 1 (RM2) is disposed in the vicinity of the sensor module 3 (SM2). ) And the antenna 2 connected to the receiving module 1 (RM2), and the antenna 2 connected to the receiving module 1 (RM3) and the receiving module 1 (RM3) is disposed in the vicinity of the sensor module 3 (SM3, SM4). In the vicinity of the sensor module 3 (SM5, SM6), a receiving module 1 (RM4) and an antenna 2 connected to the receiving module 1 (RM4) are arranged.

  Further, the receiving module 1 (RM1 to RM4) is a received signal strength measuring means 12 composed of an RSSI (Received signal strength indicator) circuit for measuring the received signal strength of the radio signal transmitted from the sensor module 3 (SM1 to SM6). It has.

  In addition, the central control module 5 causes all sensor modules 3 (SM1 to SM6) attached to the vehicle 6 to transmit data signals including temperature and pressure measurement data according to commands, and receives the modules 1 (RM1 to RM4). The received signal strength acquisition for acquiring the received signal strength for all combinations of sensor modules and antennas is performed by measuring the received signal strength for the data signal transmitted from each sensor module 3 and transmitting the measurement result. The reception signal strength is acquired from the control unit 14 and the reception signal strength acquisition control unit 14, and a signal strength table representing the reception signal strength of the data signal from the antenna measured by each reception module is created for each sensor module. A signal strength table creating means 16 for storing the created signal strength table in the storage means 20, and The received signal strength value of the data signal from the antenna is compared for each sensor module with reference to the signal strength table stored in the storage means 20, and as a result of the comparison, the antenna module that can transmit and receive the data signal with the sensor module And a data acquisition requesting means 18 for selecting an antenna from which the largest received signal strength value can be obtained and requesting the reception module corresponding thereto to acquire temperature and pressure measurement data from the sensor module. These means are constituted by a CPU, a memory, a program stored in the memory, and the like.

  Next, the processing routine of the received signal strength acquisition control means 14 that starts processing based on the ignition signal of the engine will be described based on the flowchart shown in FIG. Here, there are m sensor modules 3, each sensor module is assigned a module number i in the order of 1 to m, and there are n receiving modules 1, each receiving module having a module number k. 1 to n are assigned in order. Also, the received signal strength when the data signal transmitted from the sensor module with module number i is received by the receiving module with module number k is RSSI (i, k).

  In this processing routine, first, initialization is performed, module number i and module number k are set to 1, and RSSI (i, k) is set to zero for all i and k (step 1). . Next, the received signal strength acquisition control means 14 sends temperature and pressure measurement data to the sensor module of module number 1 through the reception module corresponding to the antenna located in the vicinity of the sensor module of module number 1. A command for transmitting the included data signal is output, and a command for acquiring RSSI (1, 1) of the data signal transmitted from the sensor module of module number 1 is output to the receiving module of module number 1 (step 2). ).

  The receiving module of module number 1 acquires the data signal from the sensor module of module number 1 via the antenna, and the RSSI (1, 1, 2) of this data signal is received using the received signal strength measuring means 12 provided inside the receiving module. ) And is output to the received signal strength acquisition control means 14 of the central control module 5, and the received signal strength acquisition control means 14 that has input the received RSSI (1, 1) The creation means 16 stores each sensor module in a signal strength table representing RSSI (i, k) of the data signal from the antenna measured by each receiving module (step 4). However, prior to step 4, the received signal strength acquisition control means 14 performs the process of step 3 for determining whether or not there is a response from the receiving module within a predetermined time. If there is no response, the RSSI (1, Step 2 of obtaining 1) is performed. If there is no response from the receiving module even after repeating the processing of step 2 a predetermined number of times, a signal indicating that the receiving module of module number 1 is faulty is output to the vehicle operation management center 7 and processing such as fault indication is performed. This can be done. Further, there is a case where there is no response from the sensor module to the receiving module due to the positional relationship between the sensor module and the receiving module. In this case, the received signal strength acquisition control means 14 signals that there is no response from the sensor module. Is received from the receiving module, this signal can be output to the vehicle operation management center 7 to display that effect.

  In the process of step 4 for storing the acquired RSSI (1, 1), the process of the receiving module of module number 1 for the sensor module of module number 1 is completed. Next, according to steps 5 and 6, the sensor module While the module number i is 1, the module number k of the receiving module is increased by 1, and the same operation is performed on the next receiving module to obtain RSSI (1, 2). After the RSSI (1, k) of the data signal from the antenna measured by all the receiving modules for the sensor module of module number 1 is obtained, the same processing is performed for the next sensor module according to Step 7 and Step 8. To obtain RSSI (2, k).

  In this way, the received signal strength acquisition control means 14 acquires RSSI (i, k) for all combinations of sensor modules and antennas, and the signal strength table creation means 16 sends each reception module for each sensor module. A signal strength table representing the RSSI (i, k) of the data signal from the antenna measured in step (b) is created, the created signal strength table is stored in the storage means 20, and the process is terminated. 3 and 4 show examples of signal strength tables stored in the storage unit 20. 3 and 4 show RSSI (i, k) of the data signal from the antenna measured by the receiving modules (RM1 to RM4) for each sensor module (SM1 to SM6). The unit is V.

  Next, the processing routine of the data acquisition request unit 18 will be described with reference to the flowchart of FIG. The data acquisition request means 18 performs processing for acquiring tire temperature and pressure measurement data, etc., related to the tire to which the sensor module is attached from each sensor module at a constant cycle. Is as follows.

  First, when there is a periodic interrupt requesting the receiving module to acquire temperature or pressure measurement data from the sensor module, the data acquisition requesting means 18 sets the module number i of the sensor module to 1 and sets the variable l as an initial condition. n is set (step 11).

  Next, the data acquisition request unit 18 refers to the signal strength table stored in the storage unit 20 and the RSSI (1, k) of the data signal from the antenna measured by the receiving module for the sensor module with the module number 1 And the receiving module that gives the maximum RSSI value as a result of the comparison is selected (step 12).

  Next, in order to obtain temperature and pressure measurement data from the sensor module of module number 1, data is transmitted and received between the sensor module of module number 1 and the receiving module corresponding to the antenna that gives the maximum RSSI value. (Step 13). Data transmission / reception is performed as follows. A signal instructing data acquisition from the sensor module of module number 1 is output to the receiving module corresponding to the antenna that gives the maximum RSSI value. The receiving module ordered to acquire data modulates this signal and transmits it to the sensor module from the antenna connected to the receiving module. The sensor module receives a signal instructing data transmission, and receives the temperature and pressure of the tire. A data signal including the measured data is transmitted. This signal can be received by an antenna connected to a receiving module that is instructed to acquire data, and the receiving module that receives this signal extracts data related to the tire by demodulation processing and sends this data to the central control module. Output.

  Next, it is determined whether or not data can be transmitted / received between the sensor module of module number 1 and the receiving module within a predetermined time, for example, 10 seconds (step 14). Then, 1 is subtracted from the variable l (step 15), and it is determined whether or not the variable l is 0 (step 16). Step 16 is a process of determining whether or not data transmission / reception has been attempted between the sensor module of module number 1 and all the receiving modules.

  When the variable l is not 0, that is, when transmission / reception of data is not attempted with all the receiving modules, the data acquisition request unit 18 refers to the signal strength table stored in the storage unit 20 and refers to the module number. Among the receiving modules excluding the receiving module corresponding to the antenna that gives the maximum RSSI value as a result of the comparison, comparing the RSSI (1, k) of the data signal from the antenna measured by the receiving module with respect to one sensor module. Thus, the reception module corresponding to the antenna giving the maximum RSSI value is selected (step 17), and the process returns to step 13.

  For example, when the signal strength table of FIG. 3 is obtained, the sensor module 3 (SM6) gives the maximum RSSI value of 2.08 V when combined with the antenna connected to the receiving module 1 (RM4). At 12, the receiving module 1 (RM4) is selected for the sensor module 3 (SM6). When data cannot be transmitted and received between the sensor module 3 (SM6) and the reception module 1 (RM4) within a predetermined time, the sensor module 3 (SM6) is connected to the antenna connected to the reception module 1 (RM2). Since the next largest RSSI value of 2.00 V is given at the time of combination, in step 17, the receiving module 1 (RM2) is selected for the sensor module 3 (SM6).

  When the signal strength table of FIG. 4 is obtained, the sensor module 3 (SM6) gives the maximum RSSI value of 2.00 V when combined with the antenna connected to the receiving module 1 (RM2). The receiving module 1 (RM2) is selected for the sensor module 3 (SM6). When data cannot be transmitted / received between the sensor module 3 (SM6) and the receiving module 1 (RM2) within a predetermined time, the sensor module 3 (SM6) is connected to the antenna connected to the receiving module 1 (RM4). Since the next largest RSSI value of 1.97 V is given at the time of combination, the receiving module 1 (RM4) is selected for the sensor module 3 (SM6) in step 17.

  In step 14, when data can be transmitted / received between the sensor module of module number 1 and the receiving module within a predetermined time, and in step 16, between the sensor module of module number 1 and all receiving modules. When data transmission / reception is attempted (when l = 0), the module number i of the sensor module is incremented by 1 (step 18).

  Next, it is determined whether the module number i of the sensor module is greater than m (i> m) (step 19). If the module number i is not larger than m, data is not transmitted / received to / from all sensor modules. Therefore, the process returns to step 12, and if the module number i is larger than m, data is transmitted / received to / from all sensor modules. Therefore, the processing routine is terminated.

  In this way, it is possible to acquire data from all sensor modules using a receiving module corresponding to an antenna arranged at a place where the received signal strength is the highest among receiving modules capable of transmitting and receiving data, Data collected in the central control module 5 is transmitted to the vehicle operation management center 7 that monitors the running state of the tire.

  As described above, this tire information management system transmits / receives data to / from the sensor module using the receiving module corresponding to the antenna arranged at the place where the received signal strength is the highest among the receiving modules capable of transmitting / receiving data. As a result, the data reception probability can be improved.

  In addition, since the receiving module corresponding to the antenna arranged in the place where the received signal strength is the largest among the receiving modules capable of transmitting and receiving data at a certain period, the data is transmitted and received with the sensor module. Even if the receiving module fails or the number of receiving modules is changed, the central control module can be shared without changing the system, and the cost can be reduced.

  In the above-described embodiment, the case where the receiving module main body and the antenna are separated has been described. However, it goes without saying that the present invention can also be applied to the case where the receiving module main body and the antenna are integrated. .

  In the above-described embodiment, the reception module measures the received signal intensity using the data signal including the temperature and pressure measurement data transmitted from the sensor module, but the data signal transmitted from the sensor module Instead of measuring the received signal strength, a predetermined reference signal for measuring the received signal strength may be transmitted from the sensor module, and the received signal strength of the reference signal may be measured.

  Next, a modification of the tire information management system of the present invention will be described. In the above embodiment, the receiving module and the antenna are arranged in the vicinity of the tire where the sensor module is provided, but only the antenna 2 is arranged in the vicinity of the tire and the receiving module 8 is integrated with the central control module 5. good. In FIG. 6, the central control module arranges one or more receiving modules 8 inside, further arranges an antenna switching means 9 between the receiving module 8 and the antenna 2, and switches the antenna switching means 9 to change the receiving module. 8 and the antenna 2 are connected, and the received signal strength of data signals from all antennas is measured by one or more receiving modules. The antenna switching means 9 can be constituted by a wiring relay, a semiconductor switch, or the like, but a port that is always connected to each antenna 2 is provided as hardware in the receiving module 8, and each port is opened and closed by software. You may comprise by what is performed in. When the receiving module is arranged in the vicinity of the tire, the receiving module is easily broken because the vicinity of the tire is a place where rocks and the like frequently fly when the vehicle travels. If only the antenna is placed near the tire and the receiving module is integrated with the central control module where rocks do not fly, the communication efficiency between the receiving module and sensor module will not be sacrificed, and damage will be caused by flying rocks, etc. Damage can be minimized by limiting the possible parts to the antenna alone. Furthermore, the structure can be simplified by integrating the receiving module and the central control module.

It is a block diagram which shows embodiment of the tire information management system of this invention. It is a flowchart which shows the processing routine of a received signal strength acquisition control means. It is a figure which shows the example of the signal strength table preserve | saved at a memory | storage means. It is a figure which shows the example of the signal strength table preserve | saved at a memory | storage means. It is a flowchart which shows the processing routine of a receiving module selection means. It is a block diagram which shows the tire information management system which has arrange | positioned only an antenna to the tire vicinity, and made the receiving module integrated with the central control module.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,8 Reception module 2 Antenna 3 Sensor module 4 Tire 5 Central control module 6 Vehicle 7 Vehicle operation management center 9 Antenna switching means 10 Tire information management system 12 Received signal strength measurement means 14 Received signal strength acquisition control means 16 Signal strength table creation Means 18 Data acquisition request means 20 Storage means

Claims (3)

Sensor modules installed in the respective tires, antennas for receiving data from these sensor modules, receiving modules connected to the antennas for acquiring data from the sensor modules, and receiving modules for data from the sensor modules In a tire information management system comprising a central control module that commands acquisition,
The reception module includes reception signal strength measurement means for measuring a reception signal strength of a data signal transmitted from the sensor module received by the antenna,
The central control module includes reception signal strength acquisition control means for acquiring reception signal strengths for combinations of all sensor modules and the antennas, and reception of data signals from the antennas measured by each reception module for each sensor module. A signal strength table creating means for creating and storing a signal strength table representing the signal strength, and referring to the signal strength table, the received signal strength value of the data signal from the antenna is compared for each sensor module to compare the data signal A data acquisition request means for selecting an antenna arranged at a position where the maximum received signal strength can be obtained from among antennas capable of transmission and reception, and requesting the reception module corresponding thereto to acquire data from the sensor module; A tire information management system comprising:   The tire information management system according to claim 2, wherein the receiving module is integrated with the central control module.   The central control module arranges the receiving module therein, further arranges antenna switching means between the receiving module and the antenna, and connects the receiving module and the antenna by switching antenna switching means. The tire information management system according to claim 1 or 2.

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