Vehicle control device

Abstract

To provide a vehicle control apparatus capable of selecting, when an error occurs in one of calculation results performed in a dual system, the result with the correct calculation result.SOLUTION: Two ECUs 3(1) and 3(2) execute the same calculation in parallel, and an ECU 4 determines the results of the calculation performed by these ECUs 3 (S1). The ECUs 3 add parity codes to the results of the calculation and output them to the ECU 4. The ECU 4 compares the two results of the calculation (S3), and performs a parity check on each result (S4, S5, S7, S10).SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a vehicle control device that detects errors in calculation results. [Background technology]

[0002] In the past, in order to detect errors in the results of calculations performed by the ECU (Electronic Control Unit) in control devices installed in vehicles, a triplex or more system configuration was used in which the same calculations were performed, and a majority vote was taken on the results of those calculations. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-229405 Summary of the Invention [Problem to be solved by the invention]

[0004] A triplex or higher configuration increases costs. Also, a dualx configuration can detect errors, but it becomes impossible to determine which calculation result is correct.

[0005] The present invention has been made in consideration of the above circumstances, and its purpose is to provide a vehicle control device that can select the correct calculation result when an error occurs in one of the calculation results performed in a dual system. [Means for solving the problem]

[0006] According to the vehicle control device of claim 1, two vehicle control devices execute the same calculation in parallel and determine the results of the calculations performed by these vehicle control devices. Then, when the two vehicle control devices output the results of the calculations with parity codes attached, the two calculation results are compared and a parity check is performed on each result. In this way, by checking the calculation results of the two vehicle control devices and the parity codes attached to those calculation results, the vehicle control device can detect an error if the calculation result of one vehicle control device is incorrect and select the correct calculation result of the other vehicle control device.

[0007] and, Claim 1 According to the described vehicle control device, first it is determined whether the results of two calculations match, and then the parity check results for each are determined. Therefore, processing efficiency can be improved by checking whether the two calculation results match or mismatch before determining the parity check results.

[0008] Claim 2 According to the described vehicle control device, if the results of two calculations match, the parity check result of one of the vehicle control devices is judged, and if the result is correct, the calculation result of the vehicle control device is output.Therefore, by judging the parity check result for one of the matching calculation results, it is possible to confirm that there is no error in the calculation result, and the correct calculation result can be output. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a flowchart showing the processing performed by an ECU having a determination function according to a first embodiment. [Figure 2] A flowchart showing the processing performed by an ECU, which is a vehicle control device. [Figure 3] Functional block diagram showing the configuration of a vehicle control device [Figure 4] 10 is a flowchart showing the processing performed by an ECU having a determination function according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] (First embodiment) As shown in FIG. 3, the vehicle control system 1 of this embodiment includes a sensor 2, ECUs 3(1) and 3(2) corresponding to vehicle control devices, an ECU 4, and an actuator 5. The sensor 2 senses, for example, the temperature and voltage of a battery mounted on the vehicle. The ECUs 3(1) and 3(2) synchronize with a system clock and execute control programs containing the same calculation content in parallel. A parity code is then assigned to the calculation result, and the result is output to the ECU 4 together with the calculation result. The parity code may be either even or odd parity.

[0013] The ECU 4 determines whether the calculation results input from the ECUs 3(1) and 3(2) are correct, and if the calculation results are correct, it controls the drive of the actuator 5 based on the calculation results. The actuator 5 is, for example, a DC-DC converter that reduces the power supply voltage of the battery to generate a control power supply, etc. Note that communication between the sensor 2 and the ECU 3 is performed using, for example, a LIN (Local Interconnect Network), and communication between the ECU 3 and the ECU 4 and between the ECU 4 and the actuator 5 is performed using, for example, a CAN (Controller Area Network; registered trademark).

[0014] Next, the operation of this embodiment will be described. As shown in Fig. 2, when the ECU 3 acquires the sensing results of the battery temperature and voltage from the sensor 2 (S21), it calculates a voltage command value for the DC-DC converter from the temperature and voltage (S22). Then, it generates a parity code for the voltage command value (S23), assigns the parity code to the voltage command value (S24), and outputs them to the ECU 4.

[0015] As shown in Fig. 1, ECU 4 first checks the parity codes received from ECU 3(1) and 3(2) (S1, S2), and then determines whether the calculation results from ECU 3(1) and 3(2) match (S3). If the calculation results match (YES), ECU 4 determines whether the parity check result for ECU 3(1) is correct (S7). If the result is correct (YES), ECU 4 outputs the calculation result of ECU 3(1) to actuator 5 (S8). If the parity check result for ECU 3(1) is incorrect (S7; NO), ECU 4 detects an error in the calculation result (S9).

[0016] In step S3, if the calculation results of both ECUs do not match (NO), it is determined whether the parity check results for each of ECU3(1) and 3(2) are correct (S4, S5). If the parity check result for ECU3(1) is correct (S4; YES), it is determined whether the parity check result for ECU3(2) is correct (S10). If the result is correct (YES), it means that a contradictory result has been obtained in which the parity check results for both ECUs are correct despite the fact that the calculation results of both ECUs do not match. Therefore, an error in the calculation result is detected (S11). If the parity check result for ECU3(2) is not correct (S10; NO), it can be said that the calculation result of ECU3(1) is correct, and therefore the calculation result of ECU3(1) is output (S8).

[0017] Conversely, if the parity check result for ECU3(1) is incorrect and the parity check result for ECU3(2) is correct (S5; YES), it can be said that the calculation result of ECU3(2) is correct, and the calculation result of ECU3(2) is output (S6).

[0018] As described above, according to this embodiment, ECU3(1) and 3(2) execute the same calculation in parallel, and ECU4 judges the results of the calculations performed by these ECUs 3. ECU3 assigns a parity code to the result of the calculation and outputs it to ECU4, which compares the results of the two calculations and performs a parity check on each result. In this way, by checking the calculation results of the two ECUs 3 and the parity codes assigned to those calculation results, ECU4 can detect an error if the calculation result of one ECU 3 is incorrect, and select the correct calculation result of the other ECU 3.

[0019] Furthermore, ECU4 first determines whether the results of the two calculations match, and then determines the respective parity check results. This improves processing efficiency by checking whether the two calculation results match or mismatch before determining the parity check results.

[0020] Furthermore, if the two calculation results match, the ECU 4 checks the parity check result of one of the ECUs 3, and if the result is correct, it outputs the calculation result of the ECU 3, and if the parity check result is incorrect, it detects an error. In this way, by checking the parity check result of one of the matching calculation results, it is possible to confirm that there is no error in that calculation result, and to output the correct calculation result.

[0021] In addition, if the results of the two calculations do not match, ECU4 judges the parity check results of both ECUs 3 and outputs the result of the calculation whose check result is correct, and if both parity check results are incorrect, it detects the error, so that even if the two calculation results do not match, the correct calculation result can be selected.

[0022] (Second embodiment) Hereinafter, the same parts as those in the first embodiment are denoted by the same reference numerals and their explanations are omitted, and only the differences will be explained. The configuration of the second embodiment is the same as that of the first embodiment, and the content of the calculations performed by the ECU 3 is also the same. However, the execution order of the processes performed by the ECU 4 is partially different from that of the first embodiment. As shown in FIG. 4, step S3 is omitted from steps S1 to S6 in the first embodiment. Then, when the determination in step S10 is "YES", step S3 is executed. If the determination here is "YES", step S8 is executed, and if the determination is "NO", step S11 is executed.

[0023] As described above, according to the second embodiment, similarly to the first embodiment, ECUs 3(1) and 3(2) execute the same calculation in parallel, and ECU 4 determines the results of the calculations executed by these ECUs 3. ECU 3 assigns a parity code to the result of the calculation and outputs it to ECU 4, which then performs a parity check on the results of the calculations executed by both ECUs 3 and outputs the result of the calculation by the ECU 3 whose check result is correct.

[0024] Specifically, if both parity check results are correct, the calculation results of the two ECUs 3 are compared, and if the results match, the calculation result of one of the ECUs 3 is output, and if the results do not match, an error is detected. Also, if both parity check results are incorrect, an error is detected. Therefore, the same effects as in the first embodiment can be obtained.

[0025] (Other embodiments) The sensor 2 is not limited to a temperature sensor or a voltage sensor. The actuator 5 is not limited to a DC-DC converter. The number of ECUs constituting the vehicle control system may be four or more. Alternatively, the number of ECUs constituting the system may be two, with one ECU being equipped with a function to compare the results of two calculations and perform a parity check on the results of each calculation. Although the present disclosure has been described with reference to the embodiments, it is understood that the present disclosure is not limited to the embodiments or structures. The present disclosure also encompasses various modifications and equivalent modifications. In addition, various combinations and forms, including only one element, more than one element, or less than one element, are also within the scope and spirit of the present disclosure. [Explanation of symbols]

[0026] In the drawing, 1 denotes a vehicle control device, 2 denotes a sensor, 3 and 4 denote ECUs, and 5 denotes an actuator.

Claims

1. Determine the results of the calculations performed by two vehicle control devices (3(1), 3(2)) that perform the same calculation in parallel; The two vehicle control devices add parity codes to the results of the calculations and output the results, and compare the two results, and perform a parity check on the results of each calculation, A vehicle control device that first determines whether the results of two calculations match, and then determines the respective parity check results.

2. 2. The vehicle control device according to claim 1, wherein if the results of the two calculations match, the parity check result of one of the vehicle control devices is judged, and if the result is correct, the calculation result of the vehicle control device is output.

3. 3. The vehicle control device according to claim 2, wherein if the parity check result is an error, the error is detected.

4. 4. A vehicle control device according to claim 2, wherein if the results of the two calculations do not match, the parity check results of both vehicle control devices are judged, and the result of the calculation whose check result is correct is output.

5. 5. A vehicle control device according to claim 4, wherein if both parity check results are incorrect, an error is detected.

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