JP5594416B1 - Electronic control unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the free time in a time partition by setting the length of the time partition corresponding to the task execution time when the task execution time changes.
An electronic control unit 201 according to the present invention uses a time partition allocated to the execution of each task included in both application programs of a non-safety-related application program 210 and safety-related application programs 211 and 212 as an application program. The time partition length derived by the conversion unit 214 that the OS 213 set for each time derives the length of the time partition corresponding to the task execution time based on the task execution time determination information 208 stored in the storage unit 206. To set the time partition in the application program.
[Selection] Figure 1

Description

  The present invention relates to an electronic control device that controls execution of a task included in an application program using a time partition.

  An automobile or a ship is equipped with an electronic control unit (hereinafter referred to as ECU) for controlling the ignition timing of the engine and the steering motor. With the advancement of control, application software (hereinafter referred to as application S / W) implemented in the ECU is becoming more complicated. In recent years, it has been demanded that the ECU conform to the functional safety standard ISO26262. The functional safety standard ISO 26262 has a function for ensuring safety even when some abnormality occurs, and is defined for the purpose of ensuring safety.

Conventionally, in order to efficiently develop a complex application S / W of an ECU while satisfying the functional safety standard, the application S / W is divided into two types of safety-related S / W components and non-safety-related S / W components. There is a method of dividing into S / W components.
The safety-related S / W component is an S / W portion that performs safety monitoring and safety control in which a method required by the functional safety standard is implemented. Further, the safety-related S / W component may be divided into a plurality of S / W components having different safety levels according to safety requirements. On the other hand, the non-safety-related S / W component is an S / W portion that performs normal control of automobiles and ships.

  By separating each S / W component in this way and ensuring its independence, the S / W component that performs normal control is defined as a non-safety-related S / W component that is excluded from the application of functional safety standards. S / W can be diverted. Further, by dividing the safety-related S / W component for each safety level, a safety technique suitable for each safety level can be applied to each S / W component. In this way, the S / W component can be efficiently developed by dividing the S / W component according to its contents.

  When a plurality of S / W components are mounted on the same microcontroller, independence between these S / W components is ensured by using a time partition that divides the execution time into a plurality of times and a spatial partition that divides the execution region into a plurality of areas. be able to. Here, independence between S / W components using a time partition will be described with reference to FIG. FIG. 13 is a time chart showing allocation of time partitions to S / W component tasks according to the background art. A task, which is an execution unit in each S / W component, is assigned to this time partition. One or more tasks exist in one S / W component, and tasks of different S / W components need to be assigned to different time partitions. Tasks with the same S / W component may be assigned to multiple time partitions.

In FIG. 13, task a and task b of the non-safety-related S / W component, task c of the safety-related S / W component 1, and task d of another safety-related S / W component 2 are assigned to time partitions 1 to 3, respectively. Assigned.
Each time partition is set with a start time and an end time, and tasks assigned in the time partition are executed only within the time between them. As a result, for example, even if an error occurs during execution of task b of the non-safety-related S / W component and task b runs away, the task b is forced to use the hardware function at the time partition break. The operation can be terminated, and it can be ensured that the operations of the task c and task d of the safety-related S / W component assigned to the time partition 2 and the time partition 3 are not affected. Therefore, it can be said that the tasks are not mixed in the processing time of the CPU, and each S / W component is independent.

As a method for controlling the execution of a task using a time partition, for example, in Patent Document 1, a normal control schedule composed of a fixed-length safety-related time partition and a fixed-length non-safety-related time partition is set to a constant cycle. A method of repeating has been proposed. The length of each time partition must be set to be equal to or greater than the worst execution time of the task to ensure that the task execution can be completed normally. The fixed length common to each set cycle inevitably increases. Therefore, when a task is completed without taking the worst execution time, unnecessary free time is generated in the time partition. Free time refers to the time in the time partition from the completion of task execution to the end time of the time partition when no other task is executed by the processor.
By switching from the normal control schedule to the safety control schedule when an abnormality is detected, the organization of the time partition in one cycle is changed. As with the normal control schedule, the fixed length of the time partition is Since it is set in accordance with the longest time of the worst execution time of the task, unnecessary free time may be generated in the time partition. (See FIG. 5 of Patent Document 1)

  Therefore, in Patent Document 2, although the length of each time partition is fixed, even if one task is completed by assigning a plurality of tasks belonging to the same S / W component in the same time partition, the same time partition is used. A method has been proposed in which another task is executed in the time partition and the free time of the time partition is reduced. (See FIG. 15 of Patent Document 2)

JP 2010-271759 A Japanese Patent No. 5136695

In the control of the ECU as in the above Patent Documents 1 and 2, the task execution time varies depending on the cycle number of the periodically executed task, the input information indicating the state of the vehicle, the previous calculation result, and the like. There is a case.
For example, immediately after the ECU is started, other ECUs do not transmit information until their own startup is completed. Therefore, a task that is calculated using information from other ECUs immediately ends the calculation process, thereby shortening the execution time. Or, on the contrary, the execution time becomes longer due to initialization processing. For example, a radar ECU that transmits various frequencies for the purpose of detecting a vehicle ahead by transmitting radio waves may change the execution time because different frequencies are used in even cycles and odd cycles. . Patent Document 1 cannot cope with this change, and Patent Document 2 has been proposed as a solution.

However, when there is only one task assigned to a certain time partition and the execution time of this task changes as described above, the method of Patent Document 2 that requires a plurality of tasks in the same time partition is applied. You can't reduce your free time.
Also, when there are multiple tasks assigned to a certain time partition and the total time of those tasks changes, even if the method of Patent Document 2 is applied, the time partition length is set sufficiently long Running all the tasks in the time partition can still cause free time.
In any case, there is a problem that unnecessary execution time in the time partition is generated because the time partition has a fixed length while the task execution time changes.

  The present invention has been made to solve the above problems, and when the execution time of the task changes, the cycle number of the task that is periodically executed, the input information indicating the state of the vehicle, the previous The purpose is to reduce the free time in the time partition by setting the length of the time partition corresponding to the execution time of the task based on information for determining the execution time of the task such as the calculation result.

  The electronic control device according to the present invention relates to arithmetic processing means, a non-safety related application program related to execution of control of the control target at normal time, and monitoring of control target abnormality or execution of control of control target at the time of abnormality At least two types of safety-related application programs to be executed, a system program for setting a time partition allocated for execution of tasks included in the application program for each application program, and task execution time for determining task execution time A storage unit that stores the determination information; and a conversion unit that derives the length of the time partition corresponding to the task execution time based on the task execution time determination information. The system program is derived by the conversion unit Time party The set time partition to the application program according to the length, the processing means is for performing a task according to the configured time partition system program.

  According to the electronic control device of the present invention, when the execution time of the task changes, the execution of the task such as the cycle number of the periodically executed task, the input information indicating the state of the vehicle, the previous calculation result, etc. By setting the length of the time partition corresponding to the task execution time based on the information for determining the time, the free time in the time partition can be reduced.

1 is a configuration diagram of a radar ECU according to a first embodiment of the present invention. It is the conversion table A which shows the length of the time partition based on cycle number information. It is a basic time chart which shows the allocation of the time partition based on Embodiment 1 of this invention. It is a time chart which shows allocation of the time partition based on a reference example. It is a time chart at the time of the error generation which shows allocation of the time partition based on Embodiment 1 of this invention. It is a time chart at the time of error occurrence which shows allocation of a time partition concerning a reference example. It is a block diagram of radar ECU which concerns on Embodiment 2 of this invention. It is the conversion table B which shows the length of the time partition in a signal processing program when a sleep flag is set. It is a conversion table C showing the length of the time partition when the cycle number information in the signal processing program is an odd number when the data number reduction flag is set. 10 is a flowchart showing the operation of the OS for setting the length of the time partition allocated to the task of the signal processing program according to the second embodiment. It is a time chart which shows allocation of a time partition at the time of a sleep flag setting. It is a time chart which shows allocation of a time partition at the time of a data number reduction flag set. It is a time chart which shows allocation of the time partition with respect to the task of S / W component concerning background art.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the same number is attached | subjected about the equivalent or corresponding element in a figure.

Embodiment 1 FIG.
The on-vehicle radar ECU 201 according to Embodiment 1 of the present invention will be described below. The radar ECU 201 has a function of transmitting / receiving radio waves, detecting a preceding vehicle from a difference in frequency of the transmitted / received radio waves, and calculating a distance and a relative speed from the own vehicle. Here, the in-vehicle radar ECU 201 is employed as the electronic control device, but the present invention is not limited to this, and various electronic control devices such as a ship, an airplane, and a robot can be employed.

  FIG. 1 is a configuration diagram of a radar ECU according to Embodiment 1 of the present invention. The radar ECU 201 includes a processor 202 that performs arithmetic processing, a transmission antenna 203 and a reception antenna 204, a transmission / reception driver 205 that controls the transmission antenna 203 and the reception antenna 204, a volatile memory (hereinafter referred to as RAM) 206 that can be read and written, and a read-only Non-volatile memory (hereinafter referred to as ROM) 207.

  The processor 202 executes an application program stored in the ROM 207. The transmission antenna 203 and the reception antenna 204 transmit and receive radio waves. The transmission / reception driver 205 transmits a radio wave from the transmission antenna 203 according to the transmission timing and transmission frequency of the radio wave set by the execution of the application program in the processor 202, and stores the frequency (measurement data) of the radio wave received from the reception antenna 204 in the RAM 206. To store. The RAM 206 stores cycle number information 208 and measurement data 209 from the transmission / reception driver 205. The ROM 207 stores a signal processing program 210, a safety monitoring program 211, an ECU management program 212, an operating system program (OS) 213, and a conversion table A214.

  Here, the processor 202 and the RAM 206 correspond to an arithmetic processing unit and a storage unit described in the claims. The signal processing program 210, the safety monitoring program 211, and the ECU management program 212 stored in the ROM 207 are all application programs, and the OS 213 is a system program.

The signal processing program 210 sets the transmission timing of the radio wave from the transmission antenna 203, calculates the distance and relative speed between the vehicle ahead and the own vehicle based on the measurement data 209 acquired using the reception antenna 204. The application program is a non-safety related application program related to the execution of control of the control target in a normal time.
The task of the signal processing program 210 needs to be started at a constant cycle in order to perform measurement and calculation periodically. In addition, the frequency band of the radio wave transmitted from the transmission antenna 203 is set to be different between the even cycle and the odd cycle.

  In the even cycle, radio waves in a frequency band intended for short-distance measurement are transmitted, and in the odd cycle, radio waves in a frequency band intended for long-range (wide range) measurement are transmitted. Furthermore, in order to increase the accuracy of the measurement result at a short distance, the sampling frequency of the frequency to be measured is larger than that at a long distance. Therefore, in an even cycle with a large number of samplings, the task execution time in the signal processing program 210 is longer than in an odd cycle.

  The safety monitoring program 211 is an application program that monitors the operation state of the transmission / reception driver 205 and the execution of the signal processing program 210 and needs to be executed in each cycle. The safety monitoring program 211 is one of safety-related application programs.

  The ECU management program 212 is an application program that causes the radar ECU 201 to sleep or shut down based on the execution result of the safety monitoring program 211. The ECU management program 212 needs to be executed once every two cycles. This ECU management program 212 is also one of safety-related application programs.

  Here, to simplify the description, it is assumed that the signal processing program 210, the safety monitoring program 211, and the ECU management program 212 executed by the processor 202 each include one task. Of course, each of these application programs may include a plurality of tasks.

  The OS 213 refers to the conversion table A214 using the cycle number information 208, and sets the start time and end time of each time partition to which the signal processing program 210, the safety monitoring program 211, and the ECU management program 212 are assigned. The cycle number information 208 is updated by a cycle counter (not shown) that the OS 213 increments by one before the signal processing program 210 is started. As described above, it is necessary to start the signal processing program 210 at a constant cycle. Considering the execution time of the safety monitoring program 211 and the ECU management program 212, one cycle is set to 50 ms.

The conversion table A214 indicates the correspondence relationship between the lengths of the time partitions in the signal processing program 210, the safety monitoring program 211, and the ECU management program 212 with respect to the cycle number information 208. This conversion table A214 is shown in FIG.
When the cycle number information 208 is an even number, the lengths of the time partitions to which the signal processing program 210 task, the safety monitoring program 211 task, and the ECU management program 212 task are assigned are 45 ms, 5 ms, and 0 ms, respectively. That is, the ECU management program 212 is not executed in even cycles.
On the other hand, when the cycle number information 208 is an odd number, the lengths of the time partitions to which the task of the signal processing program 210, the task of the safety monitoring program 211, and the task of the ECU management program 212 are assigned are 40 ms, 5 ms, and 5 ms, respectively. is there.

  As described above, since the task execution time of the signal processing program 210 is longer in the even cycle than in the odd cycle, the length of the time partition is set to 5 ms longer than the odd cycle in the even cycle. In other words, here, the worst execution time of the signal processing program 210 in the even cycle is given a margin of 45 ms, and that in the odd cycle is 40 ms. Note that the lengths of these time partitions are set in advance by estimating or actually measuring from the number of processing steps of each application program (signal processing program 210, safety monitoring program 211, ECU management program 212). is there.

A time partition allocation method will be described with reference to the time chart of FIG. 3, in which the time for which the processor 202 processes an operation, that is, the operation processing time is a time axis.
For example, when the cycle number information 208 is 2, since the cycle number information 208 is an even number, in the conversion table A214, “the length of the time partition of the signal processing program 210 is 45 ms, and the length of the time partition of the safety monitoring program 211 is The OS 213 refers to “5 ms, no time partition assigned to the ECU management program 212”. In accordance with this information, the OS 213 allocates a time partition for each application program during an arithmetic processing time of 100 ms to 150 ms. The processor 202 executes each task so that the task of the signal processing program 210 is executed during 100 to 145 ms and the task of the safety monitoring program 211 is executed during 145 to 150 ms according to the time partition set by the OS 213. Start and stop.

  When the cycle number information 208 is 3, the cycle number information 208 is an odd number. Therefore, in the conversion table A214, “the time partition length of the signal processing program 210 is 40 ms, the times of the safety monitoring program 211 and the ECU management program 212 are The OS 213 refers to the partition length of 5 ms each. In accordance with this information, the OS 213 allocates a time partition for each application program during a computation processing time of 150 ms to 200 ms. According to the time partition set by the OS 213, the processor 202 performs the task of the signal processing program 210 during 150 to 190 ms, the task of the safety monitoring program 211 during 190 ms to 195 ms, and the ECU management program 212 during 195 ms to 200 ms. Each task is started and finished so that each task is executed.

Although the execution time required for the OS 213 to set the time partition is not clearly shown in the time chart of FIG. 3, the start time and end time of each time partition of the next cycle are set at the cycle at the boundary of each cycle. Is what you are doing. However, this time partition may be set, for example, by setting the next time partition for each time partition boundary.
Here, the OS 213 sets the start time and end time of the time partition with reference to the absolute time, but may be set as a relative time from the start of the cycle.

  An example of the execution time of the task of the signal processing program 210 executed after the time partition is assigned is shown in the lower part of FIG. The task execution times when the cycle number information 208 is 0, 1, 2, 3 are 43 ms, 36 ms, 44 ms, and 38 ms, respectively. Thus, the task execution time is determined to be 45 ms or less when the cycle number information is an even number and 40 ms or less when the cycle number information is an odd number. The free time in each time partition set corresponding to the execution time of this task is 2 ms, 4 ms, 1 ms, and 2 ms. Here, each task starts executing simultaneously with the start of each time partition.

  Here, as a reference example, a time chart of a time partition allocation method when the length of the time partition is fixed in any cycle as in the control of Patent Document 1 without applying the present invention. As shown in FIG. For comparison with the configuration of the present invention, it is assumed that the task execution time in each cycle of the signal processing program 210 is the same as in FIG. The length of the time partition to which the task of the signal processing program 210 is assigned is set to 45 ms in order to set it in accordance with the worst execution time in the even cycle so that the task execution can be completed in any cycle. The length of the time partition to which the tasks of the safety monitoring program 211 and the ECU management program 212 are assigned is 5 ms. Therefore, the length of one cycle is 55 ms.

  As a result, the free time of the time partition in which the task of the signal processing program 210 is executed is 2 ms, 9 ms, 1 ms, and 7 ms, and it can be seen that the free time increases as compared with FIG. Further, since the task of the ECU management program 212 only needs to be executed once every two cycles, a time partition is assigned in any cycle, but is not executed in an even cycle. Therefore, if the length of the unnecessary time partition (pseudo free time) is also added, the sum of the free time and the pseudo free time in each cycle becomes 7 ms, 9 ms, 6 ms, and 7 ms. As compared with the above, it can be seen that the cycle number information 208 is three times or more (2 + 4 + 1 + 2 = 9 ms, 7 + 9 + 6 + 7 = 29 ms) with respect to the total free time at 0 to 4, and the use efficiency of the processor 202 is reduced.

As described above, the electronic control device 201 described in the first embodiment includes the arithmetic processing unit 202, the non-safety related application program 210 related to the execution of the control target in the normal time, and the control target abnormality. At least two types of safety-related application programs 211 and 212 related to the execution of the control of the control target at the time of monitoring or abnormality, and the time partition allocated to the execution of the tasks included in these application programs, any application A system program 213 that is also set in the program, a storage unit 206 that stores task execution time determination information 208 for determining the task execution time, and a time corresponding to the task execution time based on the task execution time determination information 208 Parte And a conversion unit 214 to derive the length of Deployment. Here, the system program 213 sets the time partition in the application program according to the length of the time partition derived to the conversion unit 214, and the arithmetic processing unit 202 executes the system program 213 to thereby execute the time partition. The task assigned in is executed.
With this configuration, unnecessary free time in each time partition can be reduced while maintaining independence among application programs (signal processing program 210, safety monitoring program 211, and ECU management program 212).

In addition to the configuration having the above effects, in the present invention, one cycle of calculation processing time by the calculation processing unit 202 includes a plurality of time partitions, and the conversion unit 214 derives the lengths of the plurality of time partitions. The length of the time partition corresponding to the task execution time is derived based on the task execution time determination information 208 for at least one time partition among the plurality of time partitions. Further, the system program 213 sets a time partition in the cycle at a predetermined period.
With this configuration, for example, when it is necessary to start execution of a task of the signal processing program 210 at a fixed period, it is easy to cope with it, and it is possible to set a time partition for one cycle at a time. Therefore, the control is not complicated. Further, since the conversion table is set in advance, the time required for setting the time partition is short, and the setting does not become complicated.

In addition, a cycle counter that is periodically incremented according to one cycle of the arithmetic processing time is provided, and the task execution time determination information 208 is based on the value of the cycle counter.
With this configuration, if the task execution time changes due to even odd cycles or changes in task processing at startup, the unused free time in each time partition is adjusted to accommodate this change in execution time. Can be reduced.

Furthermore, each cycle includes a time partition of the corresponding application program (signal processing program 210). The length of the time partition varies depending on the cycle, and the difference between the lengths of the corresponding time partitions is used. Thus, a time partition of an application program (ECU management program 212) different from the corresponding time partition is included in the cycle.
With this configuration, the number of tasks that can be executed in one cycle can be increased while shortening the length of one cycle. Specifically, in the odd cycle in which the length of the time partition of the signal processing program 210 is short, the time of the ECU management program 212 is calculated by using the short time, that is, the difference in the length of the corresponding time partition. Partitions can be added, and the usage efficiency of the processor 202 can be improved. In addition, since the time of one cycle is shorter than that of FIG. 4 of the reference example, the execution frequency of the signal processing program 210 can be increased. Since the radar ECU 201 calculates the distance and relative speed between the preceding vehicle and the host vehicle at a predetermined cycle period, the calculation frequency increases and fine control is possible.

  In the first embodiment, the time partition is set in the application program according to the length of the time partition derived to the conversion unit at a predetermined cycle for each cycle. However, the present invention is not limited to this. Only the cycle number may be set by the setting method of the present invention using the conversion unit. A specific example will be described later in the second embodiment. In the first embodiment, the length of the time partition of only the signal processing program 210 is variable within one cycle. However, the length of the time partition of a plurality of application programs may be variable within one cycle. Often, the length of the time partition of a safety-related application program can be made variable. Further, there may be a plurality of tasks in the time partition, and the length of the time partition may be derived corresponding to the total execution time of these tasks.

  Furthermore, the length of the time partition derived by the conversion unit is not limited to the absolute amount, and may be a relative change amount with respect to the length of the basic time partition. For example, a basic table that defines the organization of each time partition and its length in one cycle is prepared. In the case of a specific cycle number, the conversion unit derives the amount of change with respect to the time partition length defined in the basic table. The time partition is set in the application program according to the time partition length (absolute amount) at a specific cycle number obtained from this change amount (relative amount) and the time partition length (absolute amount) in the basic table. There may be.

  In addition, the cycle number information is classified into even and odd numbers, and the time partition length of the signal processing program 210 is set to the longer and shorter ones. For example, the cycle number information is classified into three or more. Correspondingly, the length of the time partition may be set to be different from three or more. Further, when the cycle number information 208 immediately after the start of the control by the radar ECU 201 is a small number, the length of the time partition may be set long in order to execute the initialization process.

  In the first embodiment, the system program uses the cycle number information 0, 1, 2,... That is task execution time determination information stored in the storage unit to determine whether the system program is even or odd, and refers to the conversion unit. Although the time partition is set, the conversion unit may determine even or odd numbers, or calculate the length of the time partition, and the storage unit may be even number or odd number obtained from the cycle number information. Secondary information may be stored.

  The task execution time determined by the task execution time determination information is not limited to one point such as 43 ms or 36 ms, but is determined with a certain width such as 45 ms or less or 40 ms or less as described above. However, it is sufficient if the free time of the time partition is reduced by this determination.

Next, a case where an error occurs during task execution of the signal processing program 210 using the radar ECU shown in FIG. 1 and the task is not completed within the assigned time partition will be described with reference to FIG. FIG. 5 is a time chart showing time partition assignment when an error occurs according to the first embodiment. The lower part of FIG. 5 also shows the task execution time of the signal processing program 210.
In the cycle in which the cycle number information 208 is 1, that is, when the length of the time partition of the signal processing program 210 is 40 ms, an error occurs when the task execution time of the signal processing program 210 is 36 ms. Suppose that execution of is not completed. At this time, the time partition of the signal processing program 210 is forcibly terminated after 4 ms from the occurrence of the error. When the safety monitoring program 211 assigned after the signal processing program 210 is immediately executed, it is detected that the task of the signal processing program 210 is not completed, and it is determined that an error has occurred.

With respect to the situation of FIG. 5, a case where an error occurs in the reference example shown in FIG. 4 as a case where the present invention is not applied will be described with reference to FIG. FIG. 6 is a time chart showing time partition allocation when an error occurs according to the reference example. The task execution time of the signal processing program 210 is also shown at the bottom of FIG.
The length of the time partition of each signal processing program 210 is set to 45 ms. If the error occurrence time is 36 ms, which is the same as that in FIG. 5, the time partition of the signal processing program 210 is forcibly terminated 9 ms after the occurrence of the error, because the time partition length of the signal processing program 210 is longer than that in FIG. . It is finally determined that an error has occurred by executing the safety monitoring program 211 assigned thereafter.

  As can be seen by comparing FIG. 5 and FIG. 6, the time partition length can be set in accordance with the task execution time included in the application program in FIG. 5 by applying the present invention. When an error occurs in the time partition, the time until the error is detected is shortened, and as a result, the processing can be started early with respect to the error.

Embodiment 2. FIG.
Next, a second embodiment of the present invention will be described with reference to the drawings. The description of the same components as those in the first embodiment will be omitted, and differences and new points from the first embodiment will be described in detail. FIG. 7 is a configuration diagram of the radar ECU according to the second embodiment.

  The radar ECU 801 according to the second embodiment has the following two functions in addition to the functions described in the first embodiment. First, when the radar ECU 801 is connected to another ECU (not shown) via a CAN (Controller Area Network), and the measurement stop signal is received from the other ECU, the setting of the transmission / reception driver 205 is performed. This is a function to change the radar ECU 801 to a sleep state with low power consumption after stopping the transmission / reception of radio waves at the transmission antenna 203 and the reception antenna 204 and executing the calculation using the measurement data 209. . The second function is to shorten the time required for calculation processing by reducing the number of received radio waves when the object is not detected when measuring a long distance ahead of the host vehicle. .

  The radar ECU 801 includes a CAN communication controller 802. The CAN communication controller 802 transmits and receives messages according to the communication protocol CAN with other ECUs. The communication protocol is not limited to CAN, and may be another communication protocol such as FlexRay or LIN. The CAN communication controller 802 is a specific example of an information input unit that receives information from an external device.

The RAM 803 stores a sleep flag 804 and a data number decrease flag 805 in addition to the cycle number information 208 and the measurement data 209.
The sleep flag 804 is set or cleared by the ECU management program 808. When set, it indicates that the radar ECU 801 shifts to the sleep state when the next ECU management program 808 is executed.
The data number reduction flag 805 is set or cleared by the signal processing program 807. When set, it indicates that the sampling number in the signal processing program 807 is reduced in the next odd cycle.

  Whether or not the sleep flag 804 is set and whether or not the data decrease flag 805 is set is the task execution time determination information described in the claims, and here, together with the cycle number information 208, three types of task execution times Decision information is used. Priorities are assigned to the sleep flag 804, the data number reduction flag 805, and the cycle number information 208, and a conversion table to be referred to is determined according to the priorities.

  In addition to the signal processing program 807, the safety monitoring program 211, the ECU management program 808, the conversion table A 214, and the operating system (OS) 809, the ROM 806 stores a conversion table B 810 and a conversion table C 811.

The signal processing program 807 confirms whether the sleep flag 804 is set at the beginning of each cycle. If it is set, the signal processing program 807 changes the setting of the transmission / reception driver 205 to stop transmission / reception of radio waves and measure data The calculation using 209 is not executed.
Further, the signal processing program 807 sets a data number reduction flag 805 in the RAM 803 when an object is not detected in front of the host vehicle based on a calculation result using the long-distance measurement data 209.
In addition, at the beginning of an odd cycle in which the calculation using the long-distance measurement data 209 is performed, it is confirmed whether the data number reduction flag 805 is set. And the arithmetic processing corresponding to the decreased sampling number is executed.

  When the ECU management program 808 receives a measurement stop signal from the CAN communication controller 802, the ECU management program 808 sets a sleep flag 804. In addition, after the sleep flag 804 is set, the operation of the processor 202 is stopped and the radar ECU 801 is put to sleep in order to reduce power consumption after two cycles when the ECU management program 808 is executed next. Other application programs (the signal processing program 807 and the safety monitoring program 211) after the sleep flag 804 is set and before entering the sleep state can perform an end process for the sleep.

  The conversion table B 810 indicates the length of the time partition in the signal processing program 807 when the sleep flag 804 is set. This conversion table B810 is shown in FIG. At this time, since the signal processing program 807 stops transmission / reception of radio waves from the transmission antenna 203 and the reception antenna 204, only the setting change of the transmission / reception driver 205 is performed, and the calculation using the measurement data 209 is not performed. Therefore, since the execution time is shortened, the length of the time partition assigned to the signal processing program 807 is 15 ms, and the assigned time partition is shorter than the conversion table A214.

  The conversion table C811 indicates the length of the time partition when the cycle number information in the signal processing program 807 is odd when the data number reduction flag 805 is set. This conversion table C811 is shown in FIG. At this time, the length of the time partition allocated to the signal processing program 807 is 30 ms. Since the number of data is reduced and the execution time of the signal processing program 807 is shortened, the time partition to be assigned is shorter than the conversion table A214.

  Next, the operation when the OS 809 according to the second embodiment sets the length of the time partition allocated to the task of the signal processing program 807 will be described with reference to the flowchart of FIG.

  When starting the setting of the time partition assigned to the task of the signal processing program 807, the OS 809 first refers to the sleep flag 804 in step S1101. If the sleep flag 804 is set, the process proceeds to step S1105. If the sleep flag 804 is not set, the process proceeds to step S1102.

  When the processing proceeds to step S1102, the OS 809 refers to the cycle number information 208. If the cycle number information 208 is an even number, the process proceeds to step S1106. If the cycle number information 208 is an odd number, the process proceeds to step S1103.

  When the processing proceeds to step S1103, the OS 809 refers to the data number reduction flag 805. If the data number reduction flag 805 is set, the process proceeds to step S1107. If not set, the process proceeds to step S1104. If the process proceeds to step S1104, the conversion table A214 is referred to, the time partition length is set to 40 ms, and the time partition length setting process for the signal processing program 807 is terminated.

  On the other hand, if the sleep flag 804 is set in step S1101 and the process proceeds to step S1105, the conversion table B810 is referred to, the time partition length is set to 15 ms, and the time partition of the signal processing program 807 is set. The length setting process ends.

  When the cycle number information 208 is an even number in step S1102 and the process proceeds to step S1106, the conversion table A214 is referred to, the length of the time partition is set to 45 ms, and the time partition for the signal processing program 807 is set. The length setting process ends.

  When the data number reduction flag 805 is set in step S1103 and the process proceeds to step S1107, the conversion table C811 is referred to, the time partition length is set to 30 ms, and the time partition for the signal processing program 807 is set. The length setting process ends.

  In this way, the OS 809 assigns each task execution time determination information on the right to the sleep table 804, the cycle number information 208, and the data number reduction flag 805 in order of priority, determines the conversion table to be referenced, and sets the time partition information. Set the length.

  Next, a series of processes of the OS 809 according to the flowchart of FIG. 10 when a measurement stop signal is received from another ECU will be described using the time chart shown in FIG. FIG. 11 is a time chart showing time partition allocation when the sleep flag is set.

  Assume that when the cycle number information 208 is 1, the ECU management program 808 receives a measurement stop signal from the CAN communication controller 802 and sets the sleep flag 804 when the ECU management program 808 executes a task. Next, the OS 809 ends the time partition of the ECU management program 808, increments the cycle number information 208 to 2, and starts setting the time partition of the next signal processing program 807.

  In step S1101, it is confirmed whether the sleep flag 804 is set. Here, since it is already set by the ECU management program 808, the process proceeds to step S1105. Next, referring to the conversion table B810, the length of the time partition of the signal processing program 807 is set to 15 ms, and the process ends. Since the cycle number information 208 is an even number, the length of the safety monitoring program 211 time partition is set to 5 ms, and the time partition of the ECU management program is not set.

Subsequently, when the task of the signal processing program 807 is activated, the setting of the transmission / reception driver 205 is changed and transmission / reception of radio waves is stopped. Since the calculation using the measurement data 209 is not executed, the execution time is shortened and the process is finished within 15 ms.
As a result, compared with the case where the stop process is performed in the state where the length of the time partition is fixed at 45 ms as shown in the reference example of FIG. 4 in the first embodiment, unnecessary empty space in the time partition of the signal processing program 807 is obtained. It can be seen that the time can be shortened by 30 ms.

  When the next cycle number information 208 is 3, the operation for the sleep of the radar ECU 801 in the signal processing program 807 also shortens the task execution time, so the time partition length of the signal processing program 807 is set to 15 ms. To do. The length of the time partition of the safety monitoring program 211 and the ECU management program 808 is set to 5 ms because the cycle number information 208 is an odd number. By executing each task within the set time partition, the time can be shortened by 30 ms or more compared to the reference example shown in FIG. 4, and the radar ECU 801 can be put in the sleep state.

As described above, the above-described invention according to the second embodiment changes the length of the time partition for executing the task of the signal processing program 807 based on the signal information received from another ECU. That is, the task execution time determination information (whether the sleep flag 804 is set) is based on information received from the external device by the information input means, and a time partition corresponding to the task execution time based on the task execution time determination information Is derived.
As a result, the application program (signal processing program 807, safety monitoring program 211 is also adapted to the case where the task execution time changes due to the change of the task processing content according to the vehicle state information from the external device. Unnecessary idle time in the time partition can be reduced while maintaining independence between the ECU management programs 808).

Even if the data count reduction flag 805 is set at the same time, a time partition suitable for the task execution time of the signal processing program 807 is set by checking the state of the sleep flag 804 with priority. ing. That is, a plurality of types of task execution time determination information each have a priority, and according to the priority, the task execution time determination information used for deriving the length of the time partition is determined by the conversion unit.
Therefore, the idle time can be appropriately reduced according to the amount of reduction in unnecessary idle time in the time partition, the urgency level of the task to be executed, and the like from the plural types of task execution time determination information.

  Next, a series of processing of the OS 809 according to the flowchart of FIG. 10 when an object is not detected when measuring a long distance ahead of the host vehicle will be described using the time chart shown in FIG. At this time, it is assumed that a measurement stop signal is not received from another ECU and the sleep flag 804 is not set. FIG. 12 is a time chart showing time partition assignment when the data number reduction flag is set.

When the cycle number information 208 is 1, the task of the signal processing program 807 executes transmission / reception of long-distance radio waves and arithmetic processing. Here, since no object is detected far away from the vehicle, the signal processing program 807 sets the data number reduction flag 805. Thereafter, each time the cycle number information 208 is incremented to 2 or 3, the OS 809 starts setting the time partition of the next signal processing program 807, and confirms whether the sleep flag 804 is set in step S1101. Since the sleep flag 804 is not set, the process proceeds to step S1102, and the cycle number information 208 is referred to. When the cycle number information 208 is an odd number 3, the process proceeds to step S1103.
In addition, the calculation result that an object was not detected at the time of measuring a long distance ahead of the host vehicle in an odd cycle corresponds to the execution result of the previous task in the claims.

  In step S1103, the OS 809 checks whether the data number reduction flag 805 is set. Since the data number reduction flag 805 is set when the cycle number information 208 is 1, the process advances to step S1107, the OS 809 refers to the conversion table C811, and sets the time partition length of the signal processing program 807 to 30 ms. To finish the process. The length of the time partition of the safety monitoring program 211 and the ECU management program 808 is set to 5 ms because the cycle number information 208 is an odd number as in the first embodiment.

Subsequently, when the task of the signal processing program 807 is activated, the setting of the transmission / reception driver 205 is changed to reduce the number of measurement samplings, and the arithmetic processing is executed on the measurement data 209 that is reduced by that amount. Due to the decrease, the execution time is shortened and the processing is completed within 30 ms.
As a result, as compared with the reference example shown in FIG. 4 in which the length of the time partition is fixed at 45 ms, it can be seen that the unnecessary free time of the time partition of the signal processing program 807 can be reduced by 15 ms.

As described above, another invention according to the second embodiment is that, as an execution result of the previous task, if no object is detected during long distance measurement in front of the host vehicle in the odd cycle, the data number reduction flag 805 Is set, and the length of the time partition for executing the task of the signal processing program 807 is changed in the next odd cycle. That is, the task execution time determination information (whether or not the data count reduction flag 805 is set) is based on the previous task execution result, and the time partition corresponding to the task execution time based on the task execution time determination information is determined. The length is derived.
As a result, the application program (signal processing program 807, safety monitoring program 211, ECU management) can be used even when the task execution time changes due to the change of the task content according to the previous task execution result. Unnecessary free time in the time partition can be reduced while maintaining independence among the programs 808).

  In the time charts of FIGS. 11 and 12, the time during which processing is not executed in the same cycle increases as the time partition of the signal processing program 807 is shortened. Here, as shown in the first embodiment, another time partition may be assigned and a task of another application program may be executed, so that the degree of freedom of time partition assignment is improved.

  In the second embodiment, information received via a network is used as input information from an external device, but the present invention is not limited to this. For example, the length of the time partition may be changed using information from a sensor directly connected to the radar ECU 801.

  The present invention is not limited to the configurations and operations of Embodiments 1 and 2 described above, and may be implemented by changing other configurations and operations as long as they are within the scope of the present invention.

201, 801 Radar ECU
202 Processor 206, 803 RAM
208 Cycle number information 210, 807 Signal processing program 211 Safety monitoring program 212, 808 ECU management program 213, 809 Operating system program (OS)
214 Conversion table A
802 CAN communication controller 804 Sleep flag 805 Data number decrease flag 810 Conversion table B
811 Conversion table C

Claims (7)

Arithmetic processing means;
At least two types of applications, that is, a non-safety related application program related to execution of control of the controlled object at normal time and a safety related application program related to execution of control of the controlled object at the time of abnormality monitoring of the controlled object Program and
A system program that sets, for each application program, a time partition that is allocated to the execution of tasks included in the application program;
A storage unit for storing task execution time determination information for determining the execution time of the task;
Based on the task execution time determination information, a conversion unit for deriving the length of the time partition corresponding to the execution time of the task;
With
The system program sets the time partition in the application program according to the length of the time partition derived by the conversion unit,
The electronic control device, wherein the arithmetic processing means executes the task according to the time partition set in the system program. One cycle of the calculation processing time by the calculation processing means includes a plurality of the time partitions,
The conversion unit has a conversion table for deriving the lengths of the plurality of time partitions, and at least one of the plurality of time partitions is based on the task execution time determination information for the task. Deriving the length of the time partition corresponding to the execution time,
The electronic control apparatus according to claim 1, wherein the system program sets the time partition in the cycle at a predetermined period. One cycle of the calculation processing time by the calculation processing means includes a plurality of the time partitions,
A cycle counter that is periodically incremented according to the one cycle;
The electronic control device according to claim 1, wherein the task execution time determination information is based on a value of the cycle counter. Each said cycle contains a corresponding time partition,
The length of the corresponding time partition varies depending on the cycle, and the time partition different from the corresponding time partition is included in the cycle by using the difference in length between the corresponding time partitions. The electronic control device according to claim 2 or 3. Comprising an information input means for receiving information from an external device;
The electronic control device according to claim 1, wherein the task execution time determination information is based on information received by the information input unit. 6. The electronic control device according to claim 1, wherein the task execution time determination information is based on a previous execution result of the task. Each type of task execution time determination information has a priority,
7. The electronic control according to claim 1, wherein the task execution time determination information used for deriving the length of the time partition is determined in the conversion unit according to the priority. apparatus.

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