JP2006290162A - Control unit for automobile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control unit for an automobile capable of effectively avoiding the abnormality of sleep/wake up action due to communication bus short-circuit. <P>SOLUTION: When a communication bus monitoring means detects the abnormality of communication bus and there is no wake up instruction by an internal sleep control means, since processing for forcedly changing/setting an input level of a wake up port is performed, inconvenience that the wake up port is maintained to an incorrect input level is solved and incorrect wake up and sleep based on it can be prevented. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an automobile control unit, and more particularly to an automobile control unit in which an operation mode can be switched between a normal operation mode and a sleep mode that consumes less power than the normal operation mode.

JP 2002-411141 A JP 2003-318924 A

  In order to control various devices (controlled elements) mounted on the vehicle, the vehicle is mounted with an ECU (control unit) having a CPU as a main control unit. The ECU shifts to the sleep mode under certain conditions, for example, when the vehicle is in a parked state or when there is no switch operation (Patent Documents 1 and 2). Specifically, the sleep mode is a standby mode in which the oscillator that constitutes the ECU is stopped, a slow clock mode that operates with a low-frequency oscillator different from the normal operation, or an intermittent mode in which the CPU is intermittently operated at regular intervals. It means that it is in the low current consumption mode. In particular, as in the keyless entry method, when the user who owns the portable device detects wirelessly that the user has approached the vehicle via the portable device and wants to automatically control operations such as door lock release and engine start, this control is performed. The controlling ECU must always continue to operate even when parking or when the engine is stopped. Especially when the parking time is extended for a long time, if the ECU is continuously operated in the normal operation mode, the battery voltage is lowered and the vehicle cannot be started. Therefore, the sleep control of the ECU has recently become important from the viewpoint of battery protection. It is increasing. Wake-up from sleep mode can be triggered by interrupt processing when an external program start command or input is received (hereinafter referred to as external factor wake-up), and periodically by internal timer control. There are two types of cases where sleep and wakeup are repeated (hereinafter referred to as internal factor wakeup). The latter is used for the purpose of saving power by intermittently generating a signal reception standby period from a user's portable device through a sleep period, as in a keyless entry system, for example.

  During sleep / wakeup control by an internal factor wakeup, if a wakeup signal based on, for example, a user pressing a switch is received from the outside during the sleep period, the ECU needs to wake up immediately. For this purpose, for example, a method of receiving an external wake-up signal via a communication bus at a dedicated port secured in the input / output unit of the main control unit can be obtained. However, in this case, if the communication bus is short-circuited to the ground or the power supply, a false detection of the wake-up signal occurs according to the short-circuit state of the communication bus even though the regular external wake-up signal is not received. In this case, the ECU repeats the wake-up operation frequently because the ECU performs the wake-up operation regardless of whether it is short-circuited to the ground or the power source. This leads to a problem that the power consumption increases, and on the other hand, the ECU does not wake up at the timing to wake up, leading to a problem that the control becomes impossible.

  The subject of this invention is providing the control unit for motor vehicles which can avoid the abnormality of sleep / wake-up operation | movement by the communication bus short circuit effectively.

Means for Solving the Problems and Effects of the Invention

In order to solve the above problems, the control unit for automobile of the present invention is:
A main control unit that controls the electrical operation of a controlled element on the vehicle, and the operation mode of the main control unit is between a normal operation mode and a sleep mode that consumes less power than the normal operation mode; A control unit for an automobile that is switchable,
Level valid signal to wake up the main control unit from sleep mode to normal mode, one of the binary signal levels is the first level, the other is the second level, and the first level is used as the wake-up factor A wake-up signal receiving means for receiving an external wake-up signal by communication via a communication bus at a predetermined wake-up port of the input / output unit of the main control unit;
Internal sleep control means for periodically switching the operation of the main control unit between the sleep mode and the normal mode by a timer in a state where the external wakeup signal is not recognized,
A communication bus monitoring means for monitoring the state of the communication bus;
A wake-up factor determining means for determining whether the wake-up factor when the wake-up process of the main control unit is performed is based on communication or an operation of the internal sleep control means;
Wake-up port level forced to perform processing to forcibly change and set the input level of the wake-up port when the communication bus monitoring means detects a communication bus error and there is no wake-up command from the internal sleep control means And a changing means.

  The above-described configuration of the present invention is premised on a system in which an external wakeup signal is used as an edge valid signal and is received via a communication bus at a predetermined wakeup port of the input / output unit of the main control unit. If an error occurs in the communication bus in this method, the wake-up port maintains an incorrect input level even though communication is not possible, and the wake-up and sleep transition control using the external wake-up signal is normal. It will not be done. However, in the present invention, when the communication bus monitoring means detects a communication bus abnormality and there is no wakeup command from the internal sleep control means, the process for forcibly changing and setting the input level of the wakeup port is performed. Therefore, the problem that the wake-up port is maintained at an illegal input level is solved, and illegal wake-up and sleep based on the problem can be prevented.

  If the communication bus has a dominant short circuit or recessive short circuit abnormality, the main control unit will not wake up regardless of how many times the wake-up command is issued from the outside, even though communication is not possible. The latter leads to frequent wake-up (hereinafter referred to as a second malfunction) even though no wake-up command is issued. Therefore, in the former, when the communication bus monitoring means detects a recessive short abnormality of the communication bus, the wakeup port level forcible change means forcibly changes the input level of the wakeup port to the dominant level. By performing the setting process, the first problem can be solved. In the latter case, when the communication bus monitoring means detects a dominant short abnormality of the communication bus, the wakeup port level forcible changing means forcibly changes and sets the input level of the wakeup port to the recessive level. By performing the above, the second problem can be solved.

  The wakeup port level forcible change means forcibly sets the input level of the wakeup port when the communication bus monitoring means detects an abnormality in the communication bus and there is no wakeup command from the internal sleep control means. A wake-up port level inversion means for inversion can also be used. In this configuration, an illegal recognition state of the external wakeup signal when an abnormality such as a grounding or a short circuit to the power supply has occurred in the communication bus is resolved by forcibly reversing the input level of the wakeup port. The occurrence of the first or second problem can be solved at once.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic diagram of an ECU 1 that constitutes a first configuration of an automobile control unit of the present invention. The ECU 1 includes a microprocessor (microcomputer) in which a CPU 3, a ROM 5, a RAM 4, and an input / output unit (I / O port) 2 are connected by a bus. In the present embodiment, the ECU 1 is configured as a body system ECU that controls the body system of the automobile, and FIG. 2 shows a schematic architecture thereof. The software installed on the hardware control entity composed of a microprocessor is a platform and an application for realizing a body function that operates on the platform. In addition, in order to distinguish a some application, it attached | subjected and shown with the symbol of 1-n. The platform is for giving a common operating environment to each application even when the base hardware is different. In addition to the basic software (OS) for the application, the platform is linked with the application and hardware. Although it is configured to include an interface program and the like, it is a well-known part conceptually and will not be described in detail.

The application realizes a body function that is a function related to operation of each part of the vehicle by the vehicle user. Specifically, the body system functions include control associated with opening / closing of a door, control associated with opening / closing of a window, control associated with turning on / off a light switch, control of a wireless door lock mechanism employed in a keyless entry system, etc.・ ・ Etc. Specific examples include the following:
-Driver door, passenger door, rear right seat door, rear left seat door, roof lock / unlock, power window operation, etc.
・ Power supply operation for air conditioners, car audio systems, car navigation systems, etc.
-Switch lighting control for room lamp, cockpit lamp, headlight, small lamp, hazard lamp, tail lamp, etc.

  Returning to FIG. 1, each application 1, 2,... Is stored in the ROM 5, and is executed by the CPU 3 on a work area corresponding to each application in the RAM 4. The ECU 1 controls the operation of the above-described various body-related control target devices (controlled elements) by executing each application while referring to external switches, sensors, and other input signals as necessary. However, the ECU 1 shifts to the sleep mode when a certain condition is satisfied, for example, when the vehicle is in a parking state or when there is no switch operation. Specifically, the transition to the sleep mode is performed when the entire ECU 1 is in a low power consumption mode (in this embodiment, the CPU is in a standby state for the start of the next operation). (Main control unit) The operation is shifted to the standby mode in which the operation of the main clock signal output circuit 8 that outputs the operation clock signal of 3 is stopped, and the platform portion of FIG. (Installed in the ROM 5 in FIG. 1).

  The ECU 1 is connected to another hardware control entity (for example, another ECU) via a network bus, and starts operation when a reset instruction or a wake-up factor is determined by communication via the network bus. 3 shows a state in which a plurality of applications 1, 2,... N are sequentially activated by a scheduler formed as a part of the platform function. The sleep management / control software (FIG. 1: in the ROM 5) acquires sleep control information for directly or indirectly specifying the start time and end time of the requested sleep period that differs for each application software. As shown in the upper part of FIG. 6, each application is programmed to set a timer for a requested sleep period and periodically repeat sleep and wakeup. For example, when the keyless entry method is adopted, a radio signal from the user portable device is received and input as “input of switch / sensor, etc.” in FIG. 1, and the door lock control application corresponding to the keyless entry method receives the received signal. The operation control of the ECU 1 is performed so that the standby period is the normal mode period and is repeated alternately with the sleep period.

  As shown in FIG. 1, the above-described timer is executed by each application in software during wakeup, and the next time to wake up before entering sleep is set in the sleep timer of the sleep control circuit 7. When entering the sleep mode, the sleep control circuit 7 sends a sleep signal to the main clock signal generation circuit 8 that provides the operation clock signal of the CPU 3 and stops its operation. On the other hand, when the sleep timer expires, a wakeup signal is output to the CPU 3 to shift to a wakeup process. This process is referred to as an internal wakeup process in this specification, and the wakeup signal that the sleep control circuit 7 outputs to the CPU 3 for this purpose is referred to as an internal wakeup signal. The timer measurement during the sleep is performed using a clock pulse from the sub clock signal generation circuit 6 that is operated separately from the main clock signal generation circuit 8 and continues to operate during the sleep.

  On the other hand, some or all of the applications may receive an interrupt processing command triggered by an external operation signal (light lighting, door lock release command, etc.) regardless of the sleep cycle described above. As wake up from time to time. This process is referred to as an external wake-up process in this specification. The wakeup signal (external wakeup signal) that causes the interrupt processing command is given by communication via the communication bus (network bus) in the form of a level valid signal. Specifically, as shown in FIG. 9, this external wake-up signal has one of the binary signal levels as the first level (dominant in the present embodiment) and the other as the second level (recessive in the present embodiment). The first level (dominant) is used as a wake-up factor. As shown in FIG. 1, the external wake-up signal is received by a predetermined wake-up port 120 of the input / output unit of the CPU (main control unit) 3 (wake-up signal receiving means). On the other hand, the internal wake-up signal is received at a different port 121. Therefore, it is possible to determine whether the wake-up factor is communication (that is, an external wake-up signal) or other than communication (that is, an internal wake-up signal) based on the port difference.

The ECU 100 has the following functions.
(1) Communication bus monitoring means: monitors the state of the communication bus.
(2) Wake-up factor discriminating means: Whether the wake-up factor when the wake-up processing of the CPU (main control unit) 3 is performed is based on communication or depending on the operation of the internal sleep control means (sleep control circuit) 7 It is determined whether it is a thing (that is, a cause other than communication).
(3) Level inverting means: When the communication bus monitoring means detects an abnormality in the communication bus and there is no wakeup command from the internal sleep control means, the input level of the wakeup port 120 is forcibly reversed.
The above functions are realized by executing sleep management / control software stored in the ROM 5 of FIG.

The contents of software processing for realizing the above functions by the sleep management / control software will be described below. As shown in FIG. 4, the communication bus monitoring means determines three recognition states of normal P1, indefinite P2 and abnormality P3 for the state of the communication bus, and performs monitoring by changing the recognition state among them. The conditions for state transition are as follows.
Normal to indefinite: When ECU 100 wakes up due to communication factors.
-Undefined → Normal: When successful communication is confirmed. When receiving a signal via the communication bus (network bus), a log including the designated port is stored in the reception buffer 122 (FIG. 1). By reading this content, the success or failure of communication can be determined (if communication fails, no log is left).

-Undefined → Abnormal: When the ECU 100 shifts to the sleep mode.
-Abnormal-> undefined: When ECU 100 wakes up due to communication factors.
-Abnormal → Normal: When communication is successful.
If there is no wakeup due to a communication factor, it does not transition to an indefinite state. On the other hand, if the communication is successful, the state transitions to the normal state. Therefore, the transition to the sleep mode in the undefined state means that the ECU 100 sleeps from the wake-up due to the communication factor even though the communication is not successful. This is a case where the communication factor situation that is the basis of the judgment is suspected. Therefore, it is set as a transition to an abnormal state. That is, if the ECU 100 wakes up due to a communication factor, the temporary state is always changed to an indefinite state. Then, if the success of communication is confirmed, it immediately shifts to normal, and if it shifts to sleep without confirming the success of communication, it shifts to an abnormal state. Thereby, it is possible to accurately determine a communication abnormality.

  On the premise of the above-described monitoring state transition, processing for realizing each function of the wake-up factor determination means and the level inversion means is performed according to the flow shown in FIG. That is, in J1, the communication result is stored in the reception buffer 122, while in J2, the cause of wakeup is determined. Based on the contents of these J1 and J2, in J3, the monitoring state of the communication bus is changed to the corresponding state. J5 refers to the specific determination result (J4) of J2 and the current monitoring state (J3) of the communication bus, and if there is an abnormality, the port level for receiving the external wakeup signal is forcibly set. The process to change and set is performed. Specifically, for wake-up so that it can cope with both recessive shorts (corresponding to ground shorts) and dominant shorts (corresponding to shorts to floating potential levels due to charging or power shorts) on the communication bus. This is a process for forcibly inverting the input level of the port 120.

  That is, if any of the above abnormalities occur in the communication bus, the former does not wake up no matter how many times a wake-up command is issued from outside (first failure) The latter leads to frequent wake-up (second failure) despite no wake-up command being issued. However, if the input level of the wake-up port 120 is forcibly reversed, both of the two external recognition states of the external wake-up signal are canceled, and the occurrence of the first and second problems is suppressed at once. can do.

  FIG. 6 shows a communication result storing process. In S1, the reception buffer 122 is read, and if a log remains, the bus monitoring state is normally shifted in S2. On the other hand, if there is no log remaining, nothing is done (because there may be no external wake-up signal). FIG. 7 shows a determination process of the wakeup factor. In S11, the state of the ports 120 and 121 involved in the wakeup is read, and based on which of them is dominant, whether the wakeup is due to communication, Determine if it is something else. In cases other than communication, the process proceeds to S14 and the wake-up factor is stored as others, and in the case of communication, the process proceeds to S12 and the bus monitoring state is changed indefinitely. In S13, the wake-up factor is stored as communication.

  FIG. 8 shows a flow of processing relating to setting of the wake-up level of the external wake-up port 120. In S21, it is determined which is the bus monitoring state. If it is normal, it means that communication is successful, so the signal level of the port 120 is set to dominant (first level) in order to wake up. If uncertain, the process proceeds to S23, and it is determined whether or not the wake-up factor is due to communication with reference to the stored contents. In cases other than communication, the process proceeds to S26 and the level of the port 120 is maintained. On the other hand, if the wake-up factor is due to communication in S23, the bus monitoring state is set to abnormal, and the level of the port 120 is inverted in S25. FIG. 9 is a timing chart showing the effects realized by the above processing. When the communication bus is short-circuited in the sleep state, the ECU 100 wakes up once. The monitoring state of the communication bus transitions to an indeterminate state triggered by a wake-up, and if it is determined that the communication has failed due to the log confirmation of the communication buffer 122, it transitions to an abnormal state, and thus transitions to sleep due to level inversion. This state is maintained as long as the short circuit is resolved and does not return to normal, so the sleep state continues and frequent wakeups due to the short circuit can be prevented.

The block diagram which shows the structure of ECU which concerns on the control unit for motor vehicles of this invention. FIG. 2 is a schematic diagram showing an architecture of the system of FIG. 1. The figure which shows typically the concept of the execution cycle of the some application by a scheduler. Explanatory drawing of the monitoring state transition of a communication bus. The flowchart which shows the flow of the whole process in the 2nd of the control unit for motor vehicles. FIG. 6 is a first flowchart showing details of FIG. 5. Similarly, the second flowchart. Similarly, the third flowchart. Explanatory drawing by 2nd of the control unit for motor vehicles of this invention.

Explanation of symbols

1,100 ECU (control unit for automobile)
3 CPU (Main Control Unit)
6 Sub clock signal generation circuit (sampling clock signal generation circuit)
8 Main clock signal generation circuit 23 Second D flip-flop circuit (post edge level detection storage unit)
24 1st D flip-flop circuit (change edge detection storage unit)
25 Main AND operation circuit 26 3rd D flip-flop circuit 27 Auxiliary AND operation circuit 110 Reception terminal 120 Wake-up port

Claims (7)

A main control unit that controls the electrical operation of a controlled element on the vehicle, and the operation mode of the main control unit is between a normal operation mode and a sleep mode that consumes less power than the normal operation mode; A control unit for an automobile that is switchable,
A level valid signal for waking up the main control unit from the sleep mode to the normal mode, wherein one of the binary signal levels is a first level and the other is a second level, and the first level is awakened. Wake-up signal receiving means for receiving an external wake-up signal used as an up factor by communication via a communication bus at a predetermined wake-up port of the input / output unit of the main control unit;
Internal sleep control means for periodically switching the operation of the main control unit between the sleep mode and the normal mode by a timer in a state where the external wake-up signal is not recognized;
Communication bus monitoring means for monitoring the state of the communication bus;
A wake-up factor determining unit that determines whether a wake-up factor when the wake-up process of the main control unit is performed is based on the communication or an operation of the internal sleep control unit;
Wake-up for forcibly changing and setting the input level of the wake-up port when the communication bus monitoring means detects an abnormality in the communication bus and there is no wake-up command from the internal sleep control means Port level forced change means,
An automobile control unit comprising: The automotive control unit according to claim 1, wherein the internal wakeup signal is received at a port different from the external wakeup signal at the input / output unit. When the communication bus monitoring means detects a recessive short abnormality of the communication bus, the wakeup port level forcible change means forcibly changes and sets the input level of the wakeup port to a dominant level. The automobile control unit according to claim 1 or 2, wherein the processing is performed. When the communication bus monitoring means detects a dominant short abnormality of the communication bus, the wakeup port level forcible changing means performs processing for forcibly changing and setting the input level of the wakeup port to a recessive level. The control unit for motor vehicles according to claim 1 or 2. The wakeup port level forcible change means forces the input level of the wakeup port when the communication bus monitoring means detects an abnormality in the communication bus and there is no wakeup command from the internal sleep control means. 5. The automobile control unit according to claim 1, wherein the wake-up port level reversing means for reversing is automatically provided. The communication bus monitoring means determines three recognition states of normal, indefinite, and abnormal for the state of the communication bus,
When the recognition state is normal, when the main control unit wakes up by level recognition of the communication bus, the recognition state is changed indefinitely,
When the recognition state is indefinite, when the communication is confirmed to be successful, the recognition state is normally shifted. When the main control unit shifts to the sleep mode, the recognition state is changed from undefined to abnormal. It is what
When the recognition state is abnormal, when the main control unit wakes up due to the level recognition of the communication bus, the recognition state is shifted indefinitely, and when the success of communication is confirmed, the recognition state is changed. Is a normal transition,
6. The automobile control unit according to claim 5, wherein the wakeup port level inversion means forcibly inverts the input level of the wakeup port when the recognition state by the communication bus monitoring means is abnormal. When receiving a signal via the communication bus, a reception buffer is provided for storing a log including a port designated to receive the signal, and the communication bus monitoring means leaves the log in the reception buffer. The vehicle control unit according to claim 6, wherein the success or failure of the communication is determined based on whether or not the communication is successful.

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