Electronic control device, determination method

Abstract

An electronic control device includes a reception unit that receives a data signal from an external device via a transmission path, a determination reference selection unit that determines a determination reference based on transition information of a waveform in the data signal, and a state determination unit that determines a state of a communication system including the external device, the reception unit, and the transmission path based on a transmission waveform characteristic in the data signal and the determination reference.

Description

Technical Field

[0001] This invention relates to an electronic control device and a determination method. Background Technology

[0002] Electronic control devices for autonomous driving and advanced driver assistance systems require sensor-based driving control. With the increasing speed of data signals from sensors, the degradation of signal quality due to transmission path deterioration becomes significant. Highly reliable communication between sensors and the ECU is required, and techniques for diagnosing communication quality by comparing data transmission variables with diagnostic criteria are known. Patent Document 1 discloses a diagnostic device characterized by comprising: an acquisition unit that acquires data transmission variables set according to the characteristics of the data transmission path from a transceiver device on the target path; and a diagnostic unit that diagnoses the target path based on the acquired data transmission variables and by referring to diagnostic criteria information that correlates the values ​​of the data transmission variables with good / bad judgment information.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2017-129969 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] The invention described in Patent Document 1 does not take into account the deviations of each product.

[0008] Technical means to solve the problem

[0009] The electronic control device according to a first aspect of the present invention includes: a receiving unit that receives a data signal from an external device via a transmission path; a determination reference selection unit that determines a determination reference based on waveform transition information in the data signal; and a status determination unit that determines the status of a communication system including the external device, the receiving unit, and the transmission path based on the transmission waveform characteristics in the data signal and the determination reference.

[0010] The second aspect of the present invention is a determination method executed by a computer having a receiving unit that receives data signals from an external device via a transmission path. The determination method includes: determining a determination criterion based on waveform transition information in the data signal; and determining the state of a communication system including the external device, the receiving unit, and the transmission path based on the transmission waveform characteristics in the data signal and the determination criterion.

[0011] The effects of the invention

[0012] According to the present invention, it is possible to diagnose deviations in the overall characteristics of a communication system including and transmitting / receiving devices and transmission paths. Issues, configurations, and effects other than those described above will become clear from the following description of the embodiments for carrying out the invention. Attached Figure Description

[0013] Figure 1 This is a configuration diagram of the signal transmission system in the first embodiment.

[0014] Figure 2 This is a graph showing the relationship between the loss and compensation coefficient of a communication system.

[0015] Figure 3 It is a diagram representing an eye diagram.

[0016] Figure 4 It is a conceptual diagram representing the presumed opening of an eye diagram.

[0017] Figure 5 It is a diagram that represents the characteristics of a communication system.

[0018] Figure 6 This is a flowchart illustrating the operation of the signal transmission system in the first embodiment.

[0019] Figure 7 This is a diagram showing the configuration of the signal transmission system in Modified Example 2.

[0020] Figure 8 This is a schematic diagram of the signal transmission system in the second embodiment.

[0021] Figure 9 This is a flowchart illustrating the operation of the signal transmission system in the second embodiment.

[0022] Figure 10 This is a configuration diagram of the signal transmission system in the third embodiment.

[0023] Figure 11 This is a configuration diagram of the signal transmission system in the fourth embodiment. Detailed Implementation

[0024] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The embodiments are illustrative of the present invention, and omissions and simplifications have been made as appropriate to clarify the description. The present invention can be implemented in various other forms. Unless otherwise specified, the constituent elements can be singular or plural.

[0025] To facilitate understanding of the present invention, the positions, sizes, shapes, and extents of the constituent elements shown in the accompanying drawings may not represent their actual positions, sizes, shapes, or extents. Therefore, the present invention is not limited to the positions, sizes, shapes, and extents disclosed in the accompanying drawings. As examples of various types of information, they are sometimes described using terms such as "table," "list," or "queue," but various types of information can also be represented using data structures other than these. For example, various types of information such as "XX table," "XX list," or "XX queue" can also be referred to as "XX information." When describing identification information, terms such as "identification information," "identifier," "name," "ID," and "number" are used, but these can be interchanged.

[0026] When multiple components with the same or identical functions exist, different subscripts are sometimes added to the same symbols for description. Additionally, when it is not necessary to distinguish these multiple components, the subscripts are sometimes omitted for description. In embodiments, the processing performed by executing a program is sometimes described. Here, the computer executes a program via a processor (e.g., CPU, GPU), using storage resources (e.g., memory) or interface devices (e.g., communication ports) to perform processing determined by the program. Therefore, the entity performing the processing by executing the program can also be the processor. Similarly, the entity performing the processing by executing the program can be a controller, device, system, computer, or node having a processor. The entity performing the processing by executing the program can be an arithmetic unit or a dedicated circuit containing specific processing. Here, the dedicated circuit is, for example, an FPGA (Field Programmable Gate Array), an ASIC (Application Specific Integrated Circuit), or a CPLD (Complex Programmable Logic Device).

[0027] The program can be installed onto a computer from a program source. The program source can be, for example, a program distribution server or a computer-readable storage medium. When the program source is a program distribution server, the program distribution server includes a processor and storage resources for storing the program to be distributed. The processor of the program distribution server can also distribute the program to other computers. Furthermore, in embodiments, two or more programs can be implemented as a single program, or a single program can be implemented as two or more programs.

[0028] —First Embodiment—

[0029] The following is for reference Figures 1-6 The first embodiment of the signal transmission system is described.

[0030] (constitute)

[0031] Figure 1 This is a configuration diagram of the signal transmission system S1 in the first embodiment. The location where the signal transmission system S1 is installed is not particularly limited, but in this embodiment, it is assumed that the signal transmission system S1 is installed inside a vehicle for explanation. The signal transmission system S1 includes: a sensor module 100, which has a built-in sensor 400; an ECU 300 as an Electronic Control Unit; and a transmission path 200 connecting the sensor module 100 and the ECU 300. The sensor module 100 includes: the sensor 400; and a sensor communication LSI 500 as a Large Scale Integration (LSI) for communication. The sensor communication LSI 500 includes a sensor transceiver circuit 51, which communicates with the ECU 300.

[0032] ECU 300 includes an ECU communication LSI 600 and a data processing LSI 700. The ECU communication LSI 600 includes an ECU transceiver circuit 610 for communicating with the sensor module 100, and a transmission characteristic extraction unit 620 for extracting the characteristics of the transmission waveform of the sensed signal sent to the ECU transceiver circuit 610. The data processing LSI 700 includes a data processing unit 710, a characteristic determination unit 720, a determination reference selection unit 740, and a status determination unit 750. Additionally, the data processing LSI 700 includes a non-volatile storage device (not shown) storing a dataset 730.

[0033] The data processing LSI 700 includes a CPU (not shown) as a central processing unit, a ROM (not shown) as a dedicated read storage device, and a RAM (not shown) as a read / write storage device. The CPU deploys in the RAM and executes a program stored in the ROM, thereby implementing the data processing unit 710, the feature determination unit 720, the determination reference selection unit 740, and the status determination unit 750. However, the data processing LSI 700 can use an FPGA (Field Programmable Gate Array) as a rewritable logic circuit or an ASIC (Application Specific Integrated Circuit) as an application-specific integrated circuit to replace the combination of CPU, ROM, and RAM to implement these functions.

[0034] Sensing data obtained by sensor 400 is transmitted to sensor communication LSI 500. This data is received by sensor transceiver circuit 510 located within sensor communication LSI 500 and sent as a sensing signal to transmission path 200. This sensing signal reaches ECU 300 via transmission path 200 and is input to ECU communication LSI 600. The sensing signal received by ECU transceiver circuit 610 located within LSI 600 is transmitted to data processing unit 710 of data processing LSI 700. Furthermore, while the transmission path of the sensing signal from sensor 400 to data processing unit 710 has been described, the transmission of control signals from data processing unit 710 to sensor 400 is also performed.

[0035] The transmission characteristic extraction unit 620 acquires transmission characteristic information such as waveform information and equalizer information from the ECU transceiver circuit 610, and sends this transmission characteristic information to the state determination unit 750. The equalizer information includes FFE (Feed Forward Equalizer), CLTE (Continuous Time Linear Equalizer), and DFE (Decision Feedback Equalizer). Furthermore, this equalizer information includes loss compensation coefficients used in the calculations of the ECU transceiver circuit 610 to compensate for signal loss between the sensor communication LSI 500 and the ECU communication LSI 600. In addition, the transmission characteristic extraction unit 620 has the function of deriving the transmission waveform transition information, which will be described later.

[0036] The data processing unit 710 performs the original processing of the ECU 300 using the output of the sensor 400. The processing content of the data processing unit 710 is not particularly limited, but the data processing unit 710 detects other vehicles, estimates the distance to the vehicles, and transmits the information to other ECUs, for example, based on images captured by the sensor 400, which is a camera.

[0037] The characteristic determination unit 720 classifies the characteristics of the communication system 250, which includes the sensor transceiver circuit 510, the transmission path 200, and the ECU transceiver circuit 610, into one of the following: SS, which is the lowest operating speed; TT, which is the representative value; and FF, which is the highest operating speed. The operation of the characteristic determination unit 720 will be described in detail later.

[0038] The determination criterion selection unit 740 determines the determination criterion based on the classification of the characteristic determination unit 720 and refers to the dataset 730, and sends it to the status determination unit 750. However, the determination criterion selection unit 740 may also write the determined determination criterion to a predetermined location in a storage device (not shown). The operation of the status determination unit 750 will be described in detail later. In addition, the characteristic determination unit 720 and the determination criterion selection unit 740 operate relatively infrequently, for example, when at least one of the sensor module 100, transmission path 200, and ECU 300 is replaced at the time of manufacture of the vehicle equipped with the signal transmission system S1 or after manufacture.

[0039] The status determination unit 750 compares the determination criteria sent from the determination criterion selection unit 740 with the equalizer coefficient (described later) sent from the transmission characteristic extraction unit 620 to determine whether the characteristics of the communication system 250 have deteriorated. Hereinafter, the determination criterion will also be referred to as a "threshold," and the equalizer coefficient as a "loss compensation coefficient." The status determination unit 750 operates at a higher frequency than the determination criterion selection unit 740, for example, every hour, every day, every month, or every inspection of a vehicle equipped with the signal transmission system S1. If the characteristics of the communication system 250 are determined to be deteriorated, the status determination unit 750 may transmit this information to the data processing unit 710 or to other ECUs.

[0040] (The relationship between characteristic deviation and state determination)

[0041] Before detailing each function, we will explain the impact of deviations in the characteristics of the communication system 250 on anomaly detection. Figure 2 This is a graph showing the relationship between the loss and compensation coefficient of a communication system 250 under constant power supply voltage and temperature conditions.

[0042] Figure 2 The graph shown is obtained, for example, by taking a large number of signal transmission systems S1 with the same model as the object, through prior calculations, prior experiments, etc. Figure 2 The horizontal axis in the diagram represents the magnitude of the communication system loss 250, which increases as it moves to the right. Figure 2 The vertical axis in the diagram represents the loss compensation coefficient of the equalizer in the ECU transceiver circuit 610, increasing towards the top. The ECU transceiver circuit 610 shapes the signal waveform by setting a larger loss compensation coefficient for greater losses in the communication system 250, thereby ensuring accurate A / D conversion of the signal waveform. Therefore, in Figure 2 In the middle, all of them have a tendency to rise to the right.

[0043] Furthermore, as described above, the status determination unit 750 detects the characteristics of the communication system 250 with a light processing load by monitoring the loss correction coefficient. Here, there is a problem that the relationship between the loss correction coefficient and the loss varies in each system. For example, if the value of the loss correction coefficient "6" is used as the threshold, then in the case of TT as a standard, the loss is set to 21dB as the threshold. However, even with the same loss correction coefficient value of "6", the loss is 13dB in the case of FF and 25dB in the case of SS, showing a large deviation. Of course, even in this case, if detection is required when the loss deteriorates to 12dB or more, then 13, 21, and 25 are all above 12, so there is no error in being able to perform detection. However, this would require excessively high quality, which is uneconomical.

[0044] Therefore, in this embodiment, as an initial process, the characteristics of the communication system 250 are determined, and an appropriate threshold for the loss compensation coefficient is set. This processor processing is performed by the transmission characteristic extraction unit 620, the characteristic determination unit 720, and the determination criterion selection unit 740. In the subsequent stabilization process, the state determination unit 750 compares the set threshold with the loss compensation coefficient output by the transmission characteristic extraction unit 620 each time.

[0045] (Characteristics identification)

[0046] Figure 3 This is an eye diagram, commonly used to evaluate the transmission characteristics of communication paths. The horizontal axis represents time, and the vertical axis represents voltage. An eye diagram can be said to be obtained by superimposing the waveforms of the received signals on a large number of times; in this embodiment, the number of superpositions is referred to as the "number of samples". Figure 3 The upper part represents the case where the number of samples is 2. Figure 3 The lower part represents the case where the number of samples is very large. The eye diagram is an important indicator of the size of the opening. The opening is... Figure 3 The upper hexagonal region, indicated by the symbol 901E, is located in... Figure 3 The lower part is the rhomboid region represented by the symbol 902E.

[0047] according to Figure 3 A comparison of the upper and lower parts reveals that, even when using the same communication system, the more times the images are superimposed, the narrower the opening becomes. Therefore, a sampling number is typically specified when evaluating eye diagrams. For example, the eye diagram condition might be specified as "in 10 to the power of 12 samplings, the width 902W of the opening 902E is T1 seconds or more, and the height 902H is T2V or more," etc. However, with a large number of samplings, this results in a problem where the experiment takes a long time. In this embodiment, this is solved by the following method.

[0048] Figure 4 It is a conceptual diagram representing the presumed opening of an eye diagram. Figure 4 It consists of a diagram showing the eye diagram in the upper left corner, a presumed diagram with a width of 902W shown in the lower left corner, and a presumed diagram with a height of 902H shown in the upper right corner. Figure 4 In this paper, the variable "N" represents the number of samples in the eye diagram. The inventors of this application conducted in-depth research and found that the width 902W and height 902H of the eye diagram are related to the number of samples "N". Figure 4 The "Log" shown in the various graphs represents the common logarithm, i.e., with a base of 10. Additionally, Figure 4 The two inferred graphs shown are also known as "bathtub curves" because of their similar shapes.

[0049] exist Figure 4 The estimated width 902W shown in the lower left diagram indicates that when the number of samples N is 10 squared (100 times), the width 902W is NW2; when the number of samples N is 10 to the power of 4 (10000 times), the width 902W is NW4; and when the number of samples N is 10 to the power of 12, the width 902W is NW12. Figure 4 In the estimation diagram of height 902H shown in the upper right corner, it is indicated that when the number of samples N is 10 squared, that is, 100 times, height 902H is NH2; when the number of samples N is 10 to the power of 4, that is, 10000 times, height 902H is NH4; and when the number of samples N is 10 to the power of 12, height 902H is NH12.

[0050] In this embodiment, the slope of the illustrated straight line is estimated using a small number of samples, while the width and height of the eye diagram opening are calculated using a large number of samples. For example, even when evaluating an eye diagram with 10^12 samples, only 10^2 and 10^4 eye diagrams are actually generated, thereby calculating the width and height of the 10^12 eye diagram. Furthermore, in Figure 4 In the example shown, a linear function is used for approximation, but a quadratic function can also be used.

[0051] Figure 5 This is a diagram representing the characteristics of a communication system. The width and height of the eye diagram's opening correspond to the magnitudes of random jitter (RJ) and random noise (RN), respectively. These ratios determine the switching rate of the communication system's characteristics. Specifically, the switching rate is calculated as RN / RJ. In the dataset 730, for example, it contains a combination of characteristics and switching rates, specifically information such as "SS is 0.8, TT is 1.0, FF is 1.2". The characteristic determination unit 7720 compares the calculated switching rate with the information recorded in the dataset 730 to determine the characteristics of the communication system 250. Furthermore, this switching rate is also referred to as "transmission waveform transition information".

[0052] Furthermore, in the characteristic discrimination processing of the communication system 250 described above, the transmission characteristic extraction unit 620 performs processing up to the calculation of the conversion rate, while the characteristic determination unit 720 only performs characteristic discrimination. Additionally, the data signal used by the transmission characteristic extraction unit 620 for evaluating the eye diagram with a small number of samples can be a signal specifically prepared for system characteristic evaluation, or any signal passing through the transmission path 200, such as the sensing signal output by the sensor 400.

[0053] (Selection of Judgment Criteria)

[0054] The dataset 730 stores a pre-determined loss threshold and a representation of... Figure 2 The information shows the relationship between the loss and the loss compensation coefficient for each characteristic. When the characteristic determination unit 720 selects a characteristic of the communication system 250, the determination benchmark selection unit 740 determines the threshold by referring to the dataset 730. For example, if the predetermined loss threshold is 21dB, the threshold is determined to be "6" for the characteristic TT, "4" for the characteristic SS, and "10" for the characteristic FF.

[0055] (flow chart)

[0056] Figure 6 This is a flowchart illustrating the operation of the signal transmission system S1. In the steps described below, steps S931 to S935 are initial processes, and steps S936 to S937 are stabilization processes. Furthermore, this flowchart is provided to illustrate the sequential relationship between each process and does not represent a continuous chronological order. In particular, there may sometimes be an interval of several days, months, or years between the initial and stabilization processes.

[0057] In step S931, the transmission characteristic extraction unit 620 evaluates the bathtub curve. Specifically, the transmission characteristic extraction unit 620 generates an eye diagram with a small number of samples, such as 100 or 10,000, and evaluates the width and height of the opening. In the subsequent step S932, the transmission characteristic extraction unit 620 calculates... Figure 4 The slopes of the two curves shown are used to calculate the coefficients that approximate a straight line. In the subsequent step S932, the transmission characteristic extraction unit 620 uses the coefficients calculated in step S932 to calculate the width 902W and height 902H of the eye diagram at a specified number of samples. Furthermore, the transmission characteristic extraction unit 620 also calculates the conversion rate as the ratio of width 902W to height 902H.

[0058] In the subsequent step S934, the characteristic determination unit 720 determines the characteristics of the system by referring to the dataset 730. For example, the characteristic determination unit 720 selects the characteristic with a value closest to the calculated conversion rate. In the next step S935, the determination benchmark selection unit 740 determines a threshold based on the characteristics determined by the characteristic determination unit 720 and referring to the dataset 730. In step S936, the state determination unit 750 reads the equalizer coefficient set in the ECU transceiver circuit 610 from the transmission characteristic extraction unit 620. In the subsequent step S937, the state determination unit 750 compares the threshold set in step S935 with the equalizer coefficient read in step S936 to evaluate the system.

[0059] Specifically, if the equalizer coefficient read in step S936 is greater than the threshold, the state determination unit 750 determines that an anomaly has occurred; if the equalizer coefficient read in step S936 is below the threshold, the state determination unit 750 determines that it is normal. When the processing in step S937 is completed, the state determination unit 750 returns to step S936. Alternatively, step S936 can also be started under the condition of receiving a specified signal from an external source. That is, the stabilization processing of steps S936 to S937 can begin after the initial processing shown in steps S931 to S935 is completed and a specified signal is received from an external source.

[0060] According to the first embodiment described above, the following effects can be obtained.

[0061] (1) The ECU 300, as an electronic control device, includes: an ECU transceiver circuit 610 that receives data signals from a sensor module 100, which is an external device, via a transmission path 200; a determination reference selection unit 740 that determines a determination reference, i.e., a threshold, based on waveform transition information, i.e., conversion rate, in the data signal and with reference to a dataset 730; and a state determination unit 750 that determines the state of the communication system 250 based on the transmission waveform characteristics in the data signal, i.e., the loss compensation coefficient of the equalizer, and the aforementioned threshold. Therefore, the ECU 300 can perform diagnosis corresponding to deviations in the characteristics of the communication system 250, which includes and transmits and receives related devices, i.e., the sensor module 100, the ECU 300, and the transmission path 200. This improves diagnostic accuracy. In other words, in this embodiment, by setting a threshold based on the characteristics of the communication system 250, the same diagnostic accuracy as when the deviations in the characteristics of the communication system 250 are small can be obtained.

[0062] Furthermore, equipment deviations generally involve PVT (process, power supply voltage, and temperature), but in this embodiment, allowable ranges are set for power supply voltage and temperature during diagnosis, thereby suppressing deviations and ensuring diagnostic accuracy. Additionally, the determination method in this embodiment also includes the characteristics of the transmission path between the sensor communication LSI 500 and the ECU communication LSI 600. Therefore, when using a substrate, connector, cable, relay connector, etc., as the transmission path 200, information on the transformation of the data transmission waveform affected by these characteristics can be obtained. Therefore, a determination criterion that includes process information related to the communication equipment can be selected.

[0063] (2) The transmission waveform characteristics in the data signal are equalizer waveform adjustment settings, i.e., loss compensation coefficients, used to adjust the waveform of the data signal. The status determination unit 750 determines the status of the communication unit based on the transmission waveform characteristics and the determination criteria.

[0064] (3) The ECU 300 includes a transmission characteristic extraction unit 620, which uses an eye diagram based on a first sample number N1 and an eye diagram based on a second sample number N2 to estimate the characteristics of the eye diagram in a third sample number N3 to calculate waveform transition information. N1 is, for example, 10 squared, N2 is, for example, 10 to the power of 4, and N3 is, for example, 10 to the power of 12, with N3 being larger than both N1 and N2. Therefore, the characteristics of the communication system 250 can be determined in a short time during initial processing.

[0065] (Variation Example 1)

[0066] In the first embodiment, the loss correction coefficient of the equalizer is noted for the signal shaping process performed when the ECU 300 is the receiving side of communication. However, the same method can also be applied to the signal shaping, i.e., pre-emphasis or de-emphasis, when the ECU 300 is the transmitting side. In other words, the same effect as in the first embodiment can be obtained not only when the ECU 300 is the receiving side, but also when the ECU 300 is the transmitting side.

[0067] According to this modified example 1, the following effects can be achieved.

[0068] (4) The transmission waveform characteristics of the data signal also include settings for pre-emphasis and deemphasis of the data signal waveform. Therefore, the ECU 300 can perform the same diagnostics as in the first embodiment, both when receiving data and when transmitting data.

[0069] (Variation Example 2)

[0070] Figure 7This diagram illustrates the configuration of the signal transmission system S1b in Modified Example 2. In this modified example, the ECU communication LSI 600 further includes a recording unit 628 for recording loss correction coefficients. The recording unit 628 obtains the loss correction coefficients from the ECU transceiver circuit 610 and records them as a log 629. The log 629 is recorded in a non-volatile storage device (not shown).

[0071] According to this modified example 2, the following effects can be obtained.

[0072] (5) The ECU 300 has a recording unit 628, which is used to store log data of the transmission waveform characteristics related to the data signal. Therefore, the log data can be used for post-event analysis.

[0073] (Variation Example 3)

[0074] The transmission waveform transition information extracted by the transmission characteristic extraction unit 620 may include overshoot and undershoot information. In this case, the characteristics of the communication system 250 can be determined based on the overshoot and undershoot information, i.e., voltage value and time information.

[0075] (Variation Example 4)

[0076] When determining the process based on the transformation information of the transmission waveform, instead of classifying the dataset 730, the transformation rate value can be classified to determine the process information.

[0077] (Variation Example 5)

[0078] The transmission characteristic extraction unit 620 can directly obtain the process information of the sensor transceiver circuit 510 of the sensor module 100 and the process information of the ECU transceiver circuit 610 from the outside. It can also make use of machine learning or AI technologies to determine the process information or diagnose the communication quality.

[0079] (Variation Example 6)

[0080] In the first embodiment described above, the characteristics of the communication system 250 are classified into three types. However, the number of classifications is not limited to three; two or more types are acceptable. Furthermore, the determination criterion selection unit 740 selects one of the three thresholds for the communication system 250 based on the conversion rate value, but the intermediate value can also be used as the threshold through methods such as proportional compensation.

[0081] —Second Implementation—

[0082] Reference Figures 8-9This describes a second embodiment of the signal transmission system. In the following description, the same reference numerals are used for components identical to those in the first embodiment; the main differences are explained. Aspects not specifically described are the same as in the first embodiment. The main difference in this embodiment compared to the first embodiment lies in the consideration of voltage and temperature.

[0083] Figure 8 This is a configuration diagram of the signal transmission system S2 in the second embodiment. In the signal transmission system S2, in addition to the configuration of the signal transmission system S1 in the first embodiment, the sensor module 100 also includes a power supply voltage sensor 830 and a temperature sensor 840, and the ECU 300 also includes a power supply voltage sensor 810 and a temperature sensor 820. The sensing signals from the power supply voltage sensors 810 and 830 and the temperature sensors 820 and 840 are input to the determination reference selection unit 740 of the ECU 300. Furthermore, in the dataset 730 of this embodiment, information representing the relationship between losses and loss compensation coefficients corresponding to the combinations of power supply voltage and temperature is stored for the characteristics of the SS, TT, and FF of the communication system 250.

[0084] In this embodiment, the determination criterion selection unit 740 uses not only the characteristics of the communication system 250 determined by the characteristic determination unit 720, but also information on power supply voltage and temperature to determine the threshold. That is, in this embodiment, the determination criterion selection unit 740, as an initial process, sets the threshold based on power supply voltage and temperature not only once, but every time the state determination unit 750 makes a determination.

[0085] Figure 9 This is a flowchart illustrating the operation of the signal transmission system S2 in the second embodiment. Processes identical to those in the first embodiment are assigned the same step numbers, and descriptions are omitted. In the second embodiment, step S935a is executed after step S934. Furthermore, in the second embodiment, steps S931 to S934 are initial processing steps, and steps S935a to S937 are stabilization processes.

[0086] In step S935a, the determination reference selection unit 740 reads the sensing signals from the power supply voltage sensors 810 and 830 and the temperature sensors 820 and 840, and reads the voltage and temperature values. In the subsequent step S935b, the determination reference selection unit 740 refers to the dataset 730 and sets a corresponding loss compensation coefficient, i.e., a threshold, based on the combination of voltage and temperature read in step S935a and a predetermined loss threshold. This threshold is used in step S937. The processing of steps S936 and S937 is the same as in the first embodiment. However, when the processing of step S937 ends, the process returns to step S935a.

[0087] According to the second embodiment described above, the following effects can be obtained.

[0088] (6) The determination criterion selection unit 740 of ECU 300 determines the determination criterion based on the power supply voltage and temperature information of sensor module 100 and ECU 100. Therefore, the determination criterion selection unit 740 has more information when selecting the determination criterion, enabling high-precision diagnosis.

[0089] —Third Implementation—

[0090] Reference Figure 10 A third embodiment of the signal transmission system will be described. In the following description, the same reference numerals are used for the same components as in the first embodiment; the main differences will be explained. Aspects not specifically described are the same as in the first embodiment. The main difference in this embodiment compared to the first embodiment lies in the evaluation of multiple communication systems.

[0091] Figure 10 This is a configuration diagram of the signal transmission system S3 in the third embodiment. In the signal transmission system S3, in addition to the configuration of the signal transmission system S1 in the first embodiment, the second sensor module 101 is also connected to the ECU 330 via the second transmission path 201. The ECU 330, in addition to the configuration of the first embodiment, also includes an ECU second communication LSI 601 and a second data processing LSI 701.

[0092] The second sensor module 101 includes a sensor 401 and a second sensor communication LSI 501, which includes a sensor transceiver circuit 511. The ECU second communication LSI 601 includes an ECU transceiver circuit 611 and a transmission characteristic extraction unit 621. The second data processing LSI 701 includes a data processing unit 711, a characteristic determination unit 721, a determination criterion selection unit 741, and a status determination unit 751. In this embodiment, the sensor transceiver circuit 511, the second transmission path 201, and the ECU transceiver circuit 611 are collectively referred to as the second communication system 251.

[0093] The configuration and operation of the ECU second communication LSI 601 are basically the same as those of the ECU communication LSI 600, and the configuration and operation of the second data processing LSI 701 are also basically the same as those of the data processing LSI 700. However, the predetermined loss included in the dataset 731 of the second data processing LSI 701 is the value corresponding to the second communication system 251.

[0094] According to the third embodiment described above, the following effects can be obtained.

[0095] The ECU 330 includes: an ECU transceiver circuit 611 that receives a second data signal from a second sensor module 101, which is a second external device, via a second transmission path 201; a determination reference selection unit 741 that determines a second determination reference based on waveform change information in the second data signal; and a status determination unit 751 that determines the status of the second communication system 251 based on the transmission waveform characteristics in the second data signal and the second determination reference. Therefore, since each sensor has a determination reference selection unit, a transceiver circuit, and a transmission path, diagnostics can be performed in each transmission system, and abnormal paths after diagnosis can be determined.

[0096] —Fourth Implementation—

[0097] Reference Figure 11 A fourth embodiment of the signal transmission system will be described. In the following description, the same reference numerals are used for the same components as in the first embodiment; the main differences will be explained. Aspects not specifically described are the same as in the first embodiment. The main difference from the first embodiment lies in the detection of communication system degradation at the sensor side.

[0098] Figure 11 This is a configuration diagram of the signal transmission system S4 in the fourth embodiment. Compared to the signal transmission system S1 in the first embodiment, the transmission characteristic extraction unit 620, characteristic determination unit 720, data set 730, determination reference selection unit 740, and state determination unit 750 included in the ECU 300 are moved to the sensor module 140. However, the operation of each component is the same as in the first embodiment, so the description is omitted.

[0099] According to the fourth embodiment described above, in addition to the effects of the first embodiment, a communication diagnostic function is also provided on the sensor side, thus reducing the computational load on the ECU 300. Furthermore, the communication status of the signals from the ECU 300 to the sensor module 100 can be determined.

[0100] In the above embodiments and variations, the configuration of the functional blocks is merely one example. Several functional configurations, represented as different functional blocks, may also be configured as a single unit, or the configuration represented by a single functional block diagram may be divided into two or more functions. Furthermore, a portion of the function possessed by each functional block may be incorporated into the configuration possessed by other functional blocks.

[0101] In the above embodiments and variations, the program is stored in a ROM (not shown), but it can also be stored in a non-volatile storage device. Additionally, the ECU may have an input / output interface (not shown) to read the program from other devices via the input / output interface and a medium available to the ECU when needed. Here, "medium" refers to, for example, a storage medium or communication medium removable from the input / output interface, i.e., a wired, wireless, or optical network, or a carrier wave or digital signal propagating in such a network. Furthermore, some or all of the functions implemented by the program can also be implemented by hardware circuitry or an FPGA.

[0102] The above-described embodiments and modifications can also be combined separately. Various embodiments and modifications have been described above, but the present invention is not limited to these. Other methods that can be contemplated within the spirit and scope of the present invention are also included within the scope of the present invention.

[0103] Symbol Explanation

[0104] 100… Sensor Module

[0105] 200… Transmission Path

[0106] 250… communication system

[0107] 510… Sensor transceiver circuit

[0108] 610…ECU transceiver circuit

[0109] 620…Transmission Characteristic Extraction Unit

[0110] 628…Records Department

[0111] 710…Data Processing Department

[0112] 720...Characteristics Judgment Department

[0113] 730… dataset

[0114] 740… Judgment Criterion Selection Section

[0115] 750…Status Determination Department

[0116] 810, 830… Power supply voltage sensors

[0117] 820, 840... temperature sensors.

Claims

1. An electronic control device comprising: a reception section that receives a data signal from an external device via a transmission path; a determination reference selection section that decides a determination reference based on transition information of a waveform in the data signal; a state determination section that determines a state of a communication system including the external device, the reception section, and the transmission path based on a transmission waveform characteristic in the data signal and the determination reference; and a transmission characteristic extraction section that calculates the transition information of the waveform using a feature of an eye pattern at a third sampling number N3 estimated using an eye pattern based on a first sampling number N1 and an eye pattern based on a second sampling number N2, the N3 being greater than the N1 and the N2.

2. The electronic control device according to claim 1, wherein the transmission waveform characteristic in the data signal is a waveform adjustment setting value of an equalizer or a pre-emphasis that adjusts a waveform of the data signal, and the state determination section determines a state of the communication section based on the transmission waveform characteristic and the determination reference.

3. The electronic control device according to claim 1, further comprising a recording section that saves log data of the transmission waveform characteristic related to the data signal.

4. The electronic control device according to claim 1, wherein the determination reference selection section decides the determination reference based on power supply voltage and temperature information of the external device and the electronic control device.

5. The electronic control device according to claim 1, further comprising: a second reception section that receives a second data signal from a second external device via a second transmission path; a second determination reference selection section that decides a second determination reference based on transition information of a waveform in the second data signal; and a second state determination section that determines a state of a second communication system including the second external device, the second reception section, and the second transmission path based on a second transmission waveform characteristic in the second data signal and the second determination reference.

6. A determination method executed by a computer having a reception section that receives a data signal from an external device via a transmission path, the determination method characterized by comprising the steps of: deciding a determination reference based on transition information of a waveform in the data signal; determining a state of a communication system including the external device, the reception section, and the transmission path based on a transmission waveform characteristic in the data signal and the determination reference; and calculating the transition information of the waveform using a feature of an eye pattern at a third sampling number N3 estimated using an eye pattern based on a first sampling number N1 and an eye pattern based on a second sampling number N2, the N3 being greater than the N1 and the N2. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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