JP5690492B2 - In-vehicle control device - Google Patents

Description

  The present invention relates to an in-vehicle control device.

  2. Description of the Related Art Conventionally, in an automobile engine control device, a memory (ROM: Read Only Memory) is diagnosed by a CPU in addition to a self-diagnosis of a control microcomputer (CPU: Central Processing Unit).

  Patent Document 1 below describes a technique for performing a sum check or a parity check on the entire ROM area when the power is turned on before the engine is started.

JP 2000-66963 A

  Before starting the engine, control that directly affects the engine behavior such as initialization processing of each control is concentrated. On the other hand, since the ROM diagnosis is performed on the entire area of the ROM, if the ROM diagnosis is executed before the engine is started, the calculation load of the control microcomputer is greatly affected.

  Also, due to the recent expansion of the ROM area of control microcomputers, the amount of computation per ROM diagnosis increases, and the computation burden due to ROM diagnosis may increase to the extent that the computation load affects the engine control function. is there.

  The present invention has been made to solve the above-described problems, and it is an object of the present invention to provide an in-vehicle control device capable of performing ROM diagnosis efficiently and while suppressing the influence on control calculation. .

  The in-vehicle control device according to the present invention performs memory diagnosis on a part of the read-only memory during a standby time for waiting for completion of processing outside the control program.

  According to the vehicle-mounted control apparatus according to the present invention, the memory diagnosis can be efficiently performed by effectively using the standby time of the control program. Further, since the control process itself is in the standby state during the standby time, it is possible to suppress the influence of the calculation load of the memory diagnosis process on the control process.

3 is a functional block diagram of the in-vehicle control device 100 according to Embodiment 1. FIG. It is a figure which shows the processing flow in which the microcomputer 110 performs A / D conversion. It is a figure which shows the detailed flow of step S203.

<Embodiment 1>
FIG. 1 is a functional block diagram of in-vehicle control apparatus 100 according to Embodiment 1 of the present invention. The in-vehicle control device 100 is a device that controls the control target device 200, and includes a microcomputer 110, a ROM 120, a RAM 130, and an I / O unit 140.

  The microcomputer 110 is an arithmetic device that executes a control operation on the control target device 200 in accordance with an instruction of a control program stored in the ROM 120. The microcomputer 110 has an A / D conversion function. In addition, a memory diagnosis for the ROM 120 is performed. Details of the A / D conversion function and memory diagnosis will be described later.

  The ROM 120 is a storage device that stores a control program executed by the microcomputer 110. The RAM 130 is a storage device that stores data such as variables used while the microcomputer 110 executes the control program. The I / O unit 140 is an interface that transmits and receives data and signals between the microcomputer 110 and the control target device 200.

  The control target device 200 is a device provided in the vehicle. In the following, it is assumed that the internal combustion engine is a gasoline injection type. The control target device 200 includes a sensor 210 and an actuator 220. The sensor 210 is, for example, a sensor such as an intake air amount sensor or an engine speed sensor. Actuator 220 includes a fuel injection valve.

  The in-vehicle control device 100 calculates the fuel injection amount using information obtained from the sensor 210, and outputs a signal for controlling the valve opening time of the fuel injection valve based on the calculated fuel injection amount. The in-vehicle control device 100 repeatedly executes this processing operation while the operation power is on.

  FIG. 2 is a diagram illustrating a processing flow in which the microcomputer 110 executes A / D conversion. The A / D conversion process is necessary, for example, when an analog detection value is converted into a digital value when the detection result of the sensor 210 is acquired in the control program. The control program uses the A / D conversion function provided in the microcomputer 110 to acquire a digital value necessary for control calculation. Hereinafter, each step of FIG. 2 will be described.

(FIG. 2: Step S200)
The microcomputer 110 executes a control program stored in the ROM 120. When A / D conversion is required on the control program, the microcomputer 110 starts this processing flow in the control program, thereby starting this processing flow.

(FIG. 2: Step S201)
The microcomputer 110 starts executing an A / D conversion function that the microcomputer 110 has. In general, since A / D conversion is performed on a plurality of channels, a waiting time is generated before A / D conversion is completed for all channels.

(FIG. 2: Step S202)
The microcomputer 110 determines whether or not A / D conversion has been completed for all channels. If all A / D conversions have been completed, the process flow ends. If not, the process proceeds to step S203.

(FIG. 2: Step S203)
The microcomputer 110 performs memory diagnosis on the ROM 120. The contents of the memory diagnosis include a sum check and a parity check as described in Patent Document 1, for example. In this step, the entire area of the ROM 120 is not the object of diagnosis, but only a part of the area is the object of diagnosis. When this step ends, the process returns to step S202. If A / D conversion is not completed when this step is completed, this step is repeatedly executed. Thereby, the memory diagnosis can be finally executed on the entire area of the ROM 120.

(FIG. 2: Step S203: Supplement)
The number of times this step is executed is the time required for the microcomputer 110 to complete from the start of A / D conversion, the time required for the microcomputer 110 to perform one memory diagnosis on the ROM 120, and one diagnosis. It depends on the number of bytes. As to how many bytes should be diagnosed in one memory diagnosis, an appropriate value may be determined in advance after grasping the above numerical values.

  The configuration and operation of the in-vehicle control device 100 according to Embodiment 1 have been described above. Note that the A / D conversion function does not necessarily have to be provided in the microcomputer 110, and any other A / D converter can be used. In this case, a standby time while the A / D converter is performing A / D conversion is assigned to step S203.

  As described above, according to the first embodiment, when the microcomputer 110 performs A / D conversion in the control program, a part of the ROM 120 is in a standby time until the A / D conversion processing is completed. Perform memory diagnostics on the region. Since the waiting time until the A / D conversion is completed is a time when the original control calculation is not executed, the ROM diagnosis can be performed without affecting the original control calculation of the control program. it can. In addition, since the ROM diagnosis is performed using the standby time during which the control calculation is not executed, the diagnosis can be performed efficiently.

  In the prior art, there is a method for executing ROM diagnosis during idle time. However, conventionally, the ROM diagnosis is executed in a time zone where it is predicted that a free time will surely occur, which is different from the method according to the present invention. The method according to the present invention can execute the ROM diagnosis at an arbitrary timing when the A / D conversion completion waiting time occurs, so that the ROM diagnosis process can be executed more flexibly.

  Further, in the conventional method, although the ROM diagnosis is performed during the free time, the free time is a scheduled free time, and any free time cannot be used for the ROM diagnosis. The method according to the present invention is advantageous in that any free time in which A / D conversion completion waiting time occurs can be used.

<Embodiment 2>
In the second embodiment of the present invention, a specific example of step S203 in FIG. 2 will be described. The configuration of the in-vehicle control device 100 is the same as that of the first embodiment.

  FIG. 3 is a diagram showing a detailed flow of step S203. Hereinafter, each step of FIG. 3 will be described.

(FIG. 3: Step S301)
The microcomputer 110 determines whether or not this processing flow is executed for the first time. If it is the first time, the process proceeds to step S302, and if it is not the first time, the process skips to step S304.

(FIG. 3: Step S301: Supplement)
This step is a process that takes into account that the ROM diagnosis process is divided into a plurality of times and performed little by little. That is, in order to repeatedly execute the ROM diagnosis, it is necessary to memorize how far the diagnosis has been executed last time. On the other hand, in the first ROM diagnosis, it is necessary to initialize the diagnosis parameters. Therefore, in this step, it is determined whether or not this processing flow is executed for the first time, and it is determined whether or not initialization is necessary.

(FIG. 3: Step S302)
The microcomputer 110 initializes the ROM address to be diagnosed and the ROM capacity (assuming Z bytes) to be diagnosed by one ROM diagnosis.

(FIG. 3: Step S302: Supplement)
As described in the first embodiment, the diagnosis target address and the value of Z are based on the number of times this processing flow is executed in the standby time, the total capacity of the ROM 120, etc. Stipulated in

(FIG. 3: Step S303)
The microcomputer 110 initializes the sum value SUM and the parity value PTY to 0.

(FIG. 3: Step S304)
The microcomputer 110 reads Z-byte data from the diagnosis target ROM address.

(FIG. 3: Step S305)
The microcomputer 110 adds the data read in step S304 to the sum value SUM according to the following (formula 1).
SUM = SUM + data (Formula 1)

(FIG. 3: Step S306)
The microcomputer 110 uses the data read in step S304 to calculate the parity value PTY according to (Equation 2) below.
PTY = XOR (PTY, data) (Formula 2)

(FIG. 3: Step S307)
The microcomputer 110 advances the diagnosis target ROM address by Z bytes.

(FIG. 3: Step S308)
The microcomputer 110 determines whether or not the number of bytes set in advance as one ROM diagnosis process has been diagnosed. If the diagnosis for one time is not completed, the process returns to step S304 and the same processing is repeated. If one diagnosis is completed, the process proceeds to step S309.

(FIG. 3: Step S309)
The microcomputer 110 determines whether the sum calculation and the parity calculation have been completed for the entire area of the ROM 120. If there is an area that has not been diagnosed, this process flow is terminated, and the next diagnosis target ROM address is diagnosed again when this process flow is executed next time. If the diagnosis has been completed for all areas, the process proceeds to step S310.

(FIG. 3: Step S310)
The microcomputer 110 determines whether or not the sum value SUM coincides with a predetermined prescribed value for check SUMCHK. If they are different, it is determined that a problem has occurred in the ROM 120, and the process proceeds to step S314. If they match, it is determined that the sum check has no problem, and the process proceeds to step S311.

(FIG. 3: Step S311)
The microcomputer 110 determines whether or not the parity value PTY matches a predetermined check value PTYCHK. If they are different, it is determined that a problem has occurred in the ROM 120, and the process proceeds to step S314. If they match, it is determined that there is no problem in the parity check, and the process proceeds to step S312.

(FIG. 3: Step S312)
The microcomputer 110 determines that there is no problem in the ROM 120 because there is no problem in both the sum check and the parity check, and outputs a diagnosis result to that effect.

(FIG. 3: Step S313)
The microcomputer 110 initializes the sum value SUM and the parity value PTY to 0, respectively.

(FIG. 3: Step S314)
The microcomputer 110 determines that a failure has occurred in the ROM 120 because a failure has been detected by a sum check or a parity check, and outputs a diagnosis result to that effect.
The details of step S203 have been described in the second embodiment.

<Embodiment 3>
In the first and second embodiments, it has been described that the microcomputer 110 executes the ROM diagnosis while waiting for the A / D conversion to be completed in step S202. In the third embodiment of the present invention, two specific examples of the process of executing the ROM diagnosis and the process of the control program main body will be described. The configuration of the in-vehicle control device 100 is the same as in the first and second embodiments.

<Embodiment 3: Specific example 1 of step S202>
In step S202, the microcomputer 110 starts a wait process that waits for a predetermined time. The waiting time in this wait process is set in the vicinity of the time that is assumed to be necessary for completing the A / D conversion process in the prior art, but in the third embodiment, a predetermined time out of the waiting time is set. A ratio is assigned to step S203.

  For example, if the time assumed to be necessary for the A / D conversion process is 100 μs, the microcomputer 110 activates a wait process waiting for 50 μs and proceeds to step S203. When the wait time of 50 μs ends, the microcomputer 110 executes step S203, and at least a part of the remaining 50 μs is consumed in step S203.

  The distribution ratio of the time allocated to the weight process and step S203 is not limited to this. For example, if the wait time is set shorter, more time can be allocated to step S203. Further, by adjusting the ROM capacity to be diagnosed in step S203, the processing time of the entire steps S202 to S203 can be adjusted.

<Embodiment 3: Specific example 2 of step S202>
In step S202, the microcomputer 110 starts a wait process that waits for a predetermined time. In parallel with this wait process, the process of step S203 is started. The microcomputer 110 waits until the wait process, step S203, and the A / D conversion process are completed when executing step S202 next time.

<Embodiment 3: Supplement>
Specific examples 1 and 2 may be used in combination. For example, it is conceivable to use the above specific example 1 and 2 separately for each target to be A / D converted. Specific examples 2 may be adopted when the time required for the A / D conversion process cannot be predicted, and specific examples 1 may be adopted when the time can be predicted.

  As described above, according to the third embodiment, the microcomputer 110 allocates a part of the standby time in step S202 to step S203. As a result, the ROM diagnosis process is executed as part of the standby process, so that the method according to the present invention can be smoothly introduced without greatly changing the existing A / D conversion completion standby process.

<Embodiment 4>
In the above first to third embodiments, the ROM diagnosis process can be performed, for example, before starting the engine, or can be performed when the engine is stopped.

  In the first to third embodiments described above, the ROM diagnosis is performed during the standby time for completing the A / D conversion. However, other standby times can be used. Specifically, a standby time in which the microcomputer 110 is waiting for completion of processing outside the control program can be assigned to step S203.

  DESCRIPTION OF SYMBOLS 100: Car-mounted control apparatus, 110: Microcomputer, 120: ROM, 130: RAM, 140: I / O part, 200: Control object apparatus, 210: Sensor, 220: Actuator.

Claims (2)

An arithmetic unit that executes a control program describing an operation for controlling the vehicle;
A read-only memory storing the control program;
With
The computing unit is
During the execution of the control program and during the waiting time for waiting for completion of A / D conversion occurring at an arbitrary timing during execution of the control program that is processing outside the control program, the read-only memory Perform memory diagnosis for some areas ,
The computing unit is
The memory diagnosis is executed by assigning a predetermined percentage of the waiting time to the memory diagnosis, and the waiting time is elapsed by waiting for processing outside the control program for the amount of the waiting time excluding the predetermined ratio. A vehicle-mounted control device characterized by waiting . An arithmetic unit that executes a control program describing an operation for controlling the vehicle;
A read-only memory storing the control program;
With
The computing unit is
During the execution of the control program and during the waiting time for waiting for completion of A / D conversion occurring at an arbitrary timing during execution of the control program that is processing outside the control program, the read-only memory Perform memory diagnosis for some areas,
The computing unit is
The capacity obtained by dividing the total capacity of the read-only memory by the number of times waiting for processing outside the control program to be completed is set as a capacity for diagnosing the read-only memory in one memory diagnosis. car mounting control device shall be the features.

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