JP2017123106A - Electronic control apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic control apparatus capable of activating a normal mode even in a case where abnormality in which an instruction of a program-rewriting mode is continuously output occurs.SOLUTION: An electronic control apparatus includes: a first circuit for applying, to a control terminal of a microprocessor, a first potential for activating the microprocessor in a normal mode or a second potential for activating the microprocessor in a program-rewriting mode, on the basis of an output from a mode-switching switch; a second circuit for detecting an output from the mode-switching switch every time an ignition switch is turned on (S22), counting the number of times of continuously detecting an output for applying the second potential to a control terminal of the microprocessor (S23), and determining whether the count value has reached a given value; and a third circuit for switching the potential applied to the control terminal of the microprocessor to the first potential (S25) in the case of the second circuit determining that the count value has reached the given value (S24). Further, the second circuit resets the count value after the third circuit switches to the first potential (S26).SELECTED DRAWING: Figure 2

Description

  The present invention relates to an electronic control device equipped with a functional unit capable of rewriting a program.

  For example, Patent Document 1 discloses a countermeasure when an abnormality occurs during a process of rewriting a program of a functional unit (such as a microcomputer) of an electronic control device mounted on a vehicle from a rewriting device outside the vehicle.

  In Patent Document 1, it is preliminarily specified that the process in the program rewrite mode is executed when the ignition switch is in the ON state, and the process in the normal mode is executed when the ignition switch is in the OFF state. And in patent document 1, when abnormality arises in the middle of the process by the mode which rewrites a program, an electronic control apparatus is started in normal mode by switching an ignition switch to an OFF state. As a result, even if the process of rewriting the program is interrupted in the middle due to the occurrence of an abnormality, the process does not stagnate there.

Japanese Patent Laying-Open No. 2015-098311

  However, in the technique of the above-mentioned Patent Document 1, when an abnormality occurs in which the instruction for the program rewrite mode is continuously output from the switch for outputting the instruction for the normal mode or the program rewrite mode, the ignition switch is changed to the OFF state. However, the program rewrite mode instruction is not canceled and the normal mode cannot be activated.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an electronic control device capable of starting a normal mode even when an abnormality occurs in which a program rewrite mode instruction is continuously output. .

  In order to solve the above-described problems, the present invention provides an electronic control device that switches a mode in which a microcomputer is activated based on an output from a mode switch, and sets the microcomputer in a normal mode based on an output from the mode switch. The first potential applied to the microcomputer or the second potential to activate the microcomputer in the program rewrite mode is applied to the control terminal of the microcomputer, and the output from the mode switch is detected each time the ignition switch is turned on. The second circuit that counts the number of times that the output for applying the second potential to the control terminal of the microcomputer is continuously detected and determines whether or not the count value has reached a predetermined value is counted by the second circuit When it is determined that the value has reached a predetermined value, the third time for switching the potential applied to the control terminal of the microcomputer to the first potential. With the door, the second circuit, after switching to the first potential at the third circuit, resets the count value, it is characterized.

  In the electronic control device according to the present invention, the output from the mode changeover switch when the ignition switch is turned on is monitored, and the output for instructing the start in the program rewrite mode is applied to the control terminal of the functional unit. The counter is used to count the number of times it appears continuously. When the count value of the counter reaches a predetermined value, the potential applied to the control terminal of the functional unit is switched to the first potential instructing activation in the normal mode regardless of the output from the mode switch. As a result, an abnormality that the instruction of the program rewrite mode continues to be output occurs, and even if the program can be started only in the program rewrite mode, if the count value reaches a predetermined value, it is forcibly set in the normal mode. Can be activated.

  In the electronic control device of the present invention, when the count value of the counter reaches a predetermined value and the microcomputer starts in the normal mode, the count value is reset. As a result, the program rewrite mode can be provided to the user of the vehicle by intentionally performing the start in the unintended program rewrite mode while ensuring the opportunity to start in the normal mode at a rate of at least once for the predetermined number of times. An abnormality that the instruction continues to be output can be notified.

  As described above, according to the electronic control device of the present invention, the normal mode can be activated even when an abnormality occurs in which the program rewrite mode instruction continues to be output.

The figure which shows the structural example of the vehicle-mounted system containing the electronic controller which concerns on one Embodiment of this invention. The flowchart which showed the procedure of the starting mode control process which an electronic controller performs

[Overview]
The electronic control device of the present invention monitors the state of the switch that instructs the start mode of the microcomputer. When the switch state instructing activation of the program rewrite mode is continued to some extent, the electronic control unit is forcibly activated in the normal mode regardless of the switch state. Thereby, even if an abnormality occurs in the switch, an opportunity to start in the normal mode can be secured.

  Hereinafter, an electronic control device provided by the present invention will be described in detail by taking a configuration applied to an in-vehicle system as an example.

[Configuration example of in-vehicle system]
FIG. 1 is a diagram illustrating a configuration example of an in-vehicle system 1 including an electronic control device 10 according to an embodiment of the present invention. The in-vehicle system 1 illustrated in FIG. 1 includes an electronic control device 10, a program rewrite mode transition switch 20, a program rewrite tool 30, an ignition switch 40, and a battery 50.

  The battery 50 is, for example, a 12V secondary power source mounted in an engine room or a trunk room of the vehicle. At least one battery 50 is mounted on a general vehicle. The battery 50 is connected to the + B terminal of the electronic control device 10 and is connected to the IG terminal of the electronic control device 10 via the ignition switch 40. The power supply potential of the battery 50 input to the + B terminal is referred to as “+ B potential”.

  An ignition switch (hereinafter referred to as “IG switch”) 40 is a switch disposed near the driver's seat of the vehicle, and is interposed between the battery 50 and the electronic control device 10 (IG terminal thereof). If the IG switch 40 is in the switch OFF state, the IG terminal on the switch output side can be set to a low level potential in the example of FIG. Further, in the example of FIG. 1, the IG switch 40 can set the IG terminal on the switch output side to a high level potential, that is, the power supply potential of the battery 50 if the switch is in the ON state. The power supply potential of the battery 50 input to the IG terminal is referred to as “IG potential”.

  A program rewrite mode transition switch (hereinafter referred to as “mode changeover switch”) 20 is connected to the WFSE terminal of the electronic control device 10 from the outside. The mode change switch 20 is a switch for changing a mode in which a microcomputer of the electronic control device 10 described later is activated to a normal mode or a program rewrite mode. In the example of FIG. 1, the mode changeover switch 20 can switch the WFSE terminal on the switch output side to a high level potential, that is, a potential appearing via the load R1 from the IG potential in the example of FIG. Further, if the mode changeover switch 20 is in the switch ON state, in the example of FIG. 1, the WFSE terminal on the switch output side can be set to the low level potential, that is, the GND potential that appears by grounding. The High potential and the Low potential that appear at the WFSE terminal in each switch state are input to the microcomputer (described later) via the load R2.

  Mode switching is performed for a load R1 having one end connected to the IG potential and the other end connected to the WFSE terminal, and a load R2 having one end connected to the WFSE terminal and the other end connected to the control terminal of the microcomputer. Based on the output from the switch 20, it functions as a circuit (“first circuit” in the claims) that applies to the control terminal of the microcomputer a potential for starting the microcomputer in the normal mode or a potential for starting the microcomputer in the program rewrite mode. .

  The program rewriting tool 30 is connected to the PR terminal of the electronic control device 10 from the outside. When the electronic control device 10 is activated in the program rewrite mode, the program rewrite tool 30 performs program rewrite control by communicating with a microcomputer of the electronic control device 10 described later.

  The electronic control device 10 is a device equipped with a functional unit capable of rewriting a program, and switches the mode in which the functional unit is activated based on the potential of the WFSE terminal that is an output from the mode changeover switch 20. The electronic control device 10 includes a power supply circuit 11, a state monitor circuit 12, a program rewrite mode cancel circuit 13, and a microcomputer 14. The state monitor circuit 12 corresponds to a “second circuit” in the claims, and the program rewrite mode cancel circuit 13 corresponds to a “third circuit” in the claims.

  The power supply circuit 11 inputs a voltage signal (for example, 12V system signal) of the battery 50 input to the IG terminal via the IG switch 40 in the ON state, and generates a new voltage (for example, 5V system voltage) from the voltage signal. And output to a predetermined signal line. This new voltage is used as a power source for the microcomputer 14, for example.

  The state monitor circuit 12 is connected to the IG terminal, and the IG switch 40 is in an ON state or an OFF state based on a change in potential appearing at the IG terminal, that is, whether or not a voltage signal of the battery 50 is input. Determine if there is. Further, the state monitor circuit 12 is connected to the WFSE terminal, and the mode changeover switch 20 is turned on by detecting a change in the potential appearing at the WFSE terminal, that is, whether the potential is a high potential or a low potential. Or whether it is in the OFF state.

  Further, the state monitor circuit 12 is provided with a counter 12c. When the IG switch 40 is changed from the OFF state to the ON state (IG_ON operation), the counter 12c detects that the potential appearing at the WFSE terminal is the Low potential, that is, the mode switch 20 is turned on. If it is determined that the count value C is determined, the count value C is incremented. When the IG switch 40 changes from the OFF state to the ON state (IG_ON operation), the count value C is detected as the potential appearing at the WFSE terminal being a High potential, that is, the mode changeover switch 20 is in the OFF state. If the count value C reaches a predetermined value Th, it is initialized (reset).

  The predetermined value Th is determined by the microcomputer 14 of the electronic control device 10 when an abnormality that the Low potential indicating that the mode change switch 20 is in the ON state continues to be output (hereinafter referred to as “mode change switch abnormality”) occurs. It is a value that is set so that it can be forcibly started in the normal mode. The mode change switch abnormality occurs, for example, when the electrical contact of the mode change switch 20 is fixed or the WFSE terminal is short-circuited to GND. This predetermined value Th is typically a natural number of 2 or more. From the above, the counter 12c counts the number of times the Low potential is continuously detected as the potential of the WFSE terminal detected by the state monitor circuit 12 every time the IG switch 40 is turned on, and the counted value Is used to determine whether or not a predetermined value Th has been reached.

  Furthermore, the state monitor circuit 12 is connected to the program rewrite mode cancel circuit 13, and when it is determined that the number of times the Low potential has been continuously detected at the WFSE terminal has reached a predetermined value Th, the program rewrite mode A cancel operation is instructed to the cancel circuit 13.

  The state monitor circuit 12 is connected to the + B terminal, and is always operating by receiving power directly from the battery 50. For this reason, even if the IG switch 40 is turned off, the state monitor circuit 12 holds the state of the IG switch 40, the state of the mode change switch 20, the count value C of the counter 12c, and the cancel operation instruction. be able to.

  A program rewrite mode cancel circuit (hereinafter referred to as “mode cancel circuit”) 13 is interposed between the mode changeover switch 20 and the microcomputer 14. The mode cancel circuit 13 controls whether to start the microcomputer 14 in the normal mode or the program rewrite mode based on the state of the mode switch 20 and the presence / absence of the cancel operation instructed from the state monitor circuit 12 ( Instructions).

  When there is no cancel operation instruction from the state monitor circuit 12, the mode cancel circuit 13 controls (instructs) the mode to be activated based on the state of the mode changeover switch 20. Specifically, the mode cancel circuit 13 is configured so that the mode change switch 20 is in an OFF state, that is, if the potential appearing at the WFSE terminal is a High potential, the High potential appears via the load R2 (hereinafter “first potential”). Is applied to the control terminal of the microcomputer 14. Application of the first potential instructs the microcomputer 14 to start in the normal mode. Further, the mode cancel circuit 13 sets the potential at which the Low potential appears via the load R2 (hereinafter referred to as “second potential”) when the mode switch 20 is in the ON state, that is, when the potential appearing at the WFSE terminal is the Low potential. Applied to the control terminal of the microcomputer 14. The application of the second potential instructs the microcomputer 14 to start in the program rewrite mode.

  On the other hand, the mode cancel circuit 13 performs control (instruction) for forcibly starting the microcomputer 14 in the normal mode regardless of the state of the mode change switch 20 when the cancel operation instruction is issued from the state monitor circuit 12. . Forcibly starting in the normal mode, for example, as shown in FIG. 1, the control terminal of the microcomputer 14 is set to + B voltage via the load R3 by turning on the switch SW included in the mode cancel circuit 13. It can be easily realized by connecting and raising the voltage applied to the control terminal to the first potential.

  In the example of FIG. 1, the voltage value applied to the control terminal of the microcomputer 14 by the mode cancel circuit 13 is a voltage value obtained by dividing the + B voltage by the load R3 and the load R2, so that the mode change switch 20 The voltage value applied to the control terminal of the microcomputer 14 in the normal mode when there is no abnormality is strictly different. In this regard, the microcomputer 14 determines the activation mode so that the value of the load R3 is set sufficiently large with respect to the value of the load R2 or the normal mode can be activated regardless of which voltage value is applied to the control terminal. This can be done by designing a threshold value for this purpose.

  The microcomputer 14 is a microcomputer that executes various controls in the electronic control device 10. The microcomputer 14 is a functional unit capable of rewriting a program, and in accordance with control (instruction) from the mode cancel circuit 13, if a first voltage (approximately IG potential, approximately + B potential) is applied to the control terminal, the normal mode is set. If the second voltage (substantially GND potential) is applied to the control terminal, it starts in the program rewrite mode. When the microcomputer 14 is activated in the normal mode, the microcomputer 14 performs normal control related to the traveling of the vehicle. When the microcomputer 14 is activated in the program rewriting mode, the microcomputer 14 establishes communication with the program rewriting tool 30 connected to the PR terminal, and performs program rewriting control according to the program information transmitted from the program rewriting tool 30.

  The electronic control device 10 described above is typically configured to include a central processing unit (CPU), a memory, an input / output interface, and the like, and the CPU reads a program stored in the memory. By executing the interpretation, the functions as the power supply circuit 11, the state monitor circuit 12, the mode cancel circuit 13, and the microcomputer 14 described above are exhibited.

[Startup mode switching process executed in the in-vehicle system]
With further reference to FIG. 2, processing for appropriately switching the activation mode of the electronic control device 10 performed in the in-vehicle system 1 according to an embodiment of the present invention will be described. FIG. 2 is a flowchart showing the procedure of the start mode control process executed by the electronic control device 10. Note that the counter 12c of the state monitor circuit 12 is initialized when the vehicle is shipped, and the count value C is assumed to be zero.

  The start mode control process shown in FIG. 2 is started, for example, when the power state of the vehicle becomes the accessory power on state (ACC_ON). When the start mode control process is started, the electronic control unit 10 monitors the state of the IG switch 40 (S21).

  If the change of the potential appearing at the IG terminal is detected and it is determined that the IG switch 40 has changed from the OFF state to the ON state (IG_ON operation) (S21: Yes), the electronic control unit 10 The state is determined (S22).

  When the High potential appearing at the WFSE terminal is detected and it is determined that the mode switch 20 is in the OFF state (S22: No), the electronic control unit 10 is activated in the normal mode (S25). If it is determined in step S22 that the operation has been started in the normal mode, it is determined that no mode change switch abnormality has occurred. When the electronic control unit 10 is activated in the normal mode, the electronic control unit 10 initializes the counter 12c of the state monitor circuit 12 and resets the count value C (S26).

  On the other hand, when the Low potential appearing at the WFSE terminal is detected and it is determined that the mode switch 20 is in the ON state (S22: Yes), the electronic control unit 10 increments the counter 12c of the state monitor circuit 12 and counts it. The value C is increased by 1 (S23). Then, the electronic control unit 10 determines whether or not the count value C of the counter 12c has reached a predetermined value Th (S24).

  When it is determined in step S24 that the count value C of the counter 12c has not reached the predetermined value Th (S24: No), the electronic control unit 10 is activated in the program rewrite mode (S27). When the program rewrite mode is activated in the determination in step S24, it is impossible to determine whether or not a mode change switch abnormality has occurred.

  On the other hand, when it is determined in step S24 that the count value C of the counter 12c has reached the predetermined value Th (S24: Yes), the electronic control unit 10 determines that a mode change switch abnormality has occurred, Therefore, it starts in the normal mode (S25). When the electronic control unit 10 is activated in the normal mode, the electronic control unit 10 initializes the counter 12c of the state monitor circuit 12 and resets the count value C (S26).

  The processes in steps S21 to S27 are repeatedly executed until, for example, the power state of the vehicle becomes the power off state (ACC_OFF) (S28).

[Operations and effects of the embodiment]
As described above, according to the electronic control device 10 according to an embodiment of the present invention, the potential appearing at the end of the mode switch 20 when the IG switch 40 changes from the OFF state to the ON state (IG_ON operation) is monitored. . Then, the counter 12c counts the number of times that the Low potential for applying the second potential for instructing activation in the program rewrite mode to the control terminal of the microcomputer 14 appears continuously at the end of the mode changeover switch 20. When the count value C reaches a predetermined value Th, a first potential for instructing activation in the normal mode is applied to the control terminal of the microcomputer 14 regardless of the potential at the end of the mode switch 20.

  As a result, even if the mode changeover switch malfunctions and can be activated only in the program rewrite mode, the normal mode can be forcibly activated if the count value C reaches the predetermined value Th. . Therefore, it is possible to avoid a state in which the vehicle cannot be moved at all when a mode change switch abnormality occurs, and it is possible to travel to a place where maintenance can be received, such as a maintenance shop.

  Further, in the electronic control apparatus 10 according to the present embodiment, the counter 12c is initialized after determining that the mode change switch abnormality has occurred due to the count value C reaching the predetermined value Th. When the counter 12c is initialized, a mode change switch abnormality occurs, and even if it can be activated only in the program rewrite mode, activation in the normal mode is performed at a rate of once per the predetermined value Th. An opportunity to be able to In addition, by intentionally starting up in an unintended program rewrite mode, it is possible to notify a vehicle user or the like of a mode change switch abnormality.

  The present invention can be used for an electronic control device equipped with a functional unit capable of rewriting a program, and is particularly useful when it is desired to start the normal mode even when an abnormality occurs in which an instruction of the program rewriting mode is continuously output. is there.

DESCRIPTION OF SYMBOLS 1 In-vehicle system 10 Electronic controller 11 Power supply circuit 12 Status monitor circuit 12c Counter 13 Program rewrite mode cancellation circuit 14 Microcomputer 20 Program rewrite mode changeover switch 30 Program rewrite tool 40 Ignition switch 50 Battery

Claims (1)

An electronic control device that switches the mode in which the microcomputer starts based on the output from the mode switch,
A first circuit for applying a first potential for starting the microcomputer in a normal mode or a second potential for starting the microcomputer in a program rewrite mode to a control terminal of the microcomputer based on an output from the mode switch;
Each time the ignition switch is turned on, the output from the mode change switch is detected, the number of times that the output for applying the second potential to the control terminal of the microcomputer is continuously detected is counted, and the count value is predetermined. A second circuit for determining whether or not a value of
A third circuit that switches the potential applied to the control terminal of the microcomputer to the first potential when the second circuit determines that the count value has reached the predetermined value;
The second circuit resets the count value after being switched to the first potential in the third circuit.
Electronic control device.

Images