JP2011111089A - Seat belt retractor control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem that ECU and EEPROM or Flash are composed in separate blocks and the mounting region of the EEPROM or the Flash is required besides the mounting area of the ECU on a circuit board so that miniaturization of a seat belt retractor control device is difficult, and a problem that opening/closing information of a door required for a seat belt control device or a storage place of fastening information of a buckle switch is not clearly indicated in conventional technology. <P>SOLUTION: The seat belt retractor control device controls a vehicle seat belt, an actuator capable of driving the seat belt in a winding direction and an unwinding direction, and the actuator. The control device include a control operation circuit arranged in the control device and a circuit for carrying out communication with an apparatus outside the control device. A power supply source for supplying power for the operation circuit is configured by using an one exclusive IC. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a seat belt retractor control device for a vehicle.

  According to FIG. 3, FIG. 8, FIG. 12, and FIG. 14 in the seat belt retractor described in Patent Document 1, the ECU (163) and the data storage unit (164) in the controller (16) are separate blocks. In addition, the data storage unit (164) is described as EEPROM or Flash. Furthermore, a plurality of control parameters and set value change condition tables are stored in advance in the data storage unit.

  According to FIG. 1 in the seat belt system described in Patent Document 2, the CPU (23) and the EEPROM (24) are separate blocks. The EEPROM (24) includes a millimeter wave radar (60), motors (3a, 3b). ) Failure information is stored.

  According to FIG. 1, in the pre-crash seat belt device described in Patent Document 3, the CPU (23) and the EEPROM (24) are separate blocks. The EEPROM (24) includes a millimeter wave radar (60), a motor (3a , 3b) is stored.

  According to FIG. 1 in the operating device of the passenger protection system described in Patent Document 4, the electric circuit of the operating device is configured using a signal processing ASIC (45), a power supply ASIC (42), and a power ASIC (43). Yes.

JP 2008-143275 A JP 2005-263040 A JP 2005-271729 A Japanese Utility Model Publication No. 7-023672

  According to the above prior art, the ECU and the EEPROM or Flash are separate blocks, and in addition to the mounting area of the ECU on the circuit board, the mounting area of the EEPROM or Flash is necessary, and the seat belt retractor control device can be downsized. It was difficult. In the conventional apparatus, a plurality of control parameters and setting value change condition tables are stored in advance, or other control apparatus such as a millimeter wave radar, or failure information of a motor to be controlled is stored. . However, the storage location of door opening / closing information and buckle switch fastening information necessary for the seat belt control device is not clearly shown. Furthermore, the electric circuit of the actuator is composed of three ASICs, ie, a signal processing ASIC, a power supply ASIC, and a power ASIC, each of which requires a mounting area on the circuit board. Further cost reduction was necessary.

  In order to solve the above problems, one of the desirable aspects of the present invention is as follows.

  In a vehicle seat belt, an actuator capable of driving the seat belt in a winding direction and a delivery direction, and a seat belt retractor control device that controls the actuator, the control device includes a control arithmetic circuit provided in the control device, And a circuit that communicates with devices outside the control device, and a power supply circuit that supplies power for the arithmetic circuit is configured using one dedicated IC.

  According to the present invention, the main part of the electric circuit is configured by using a dedicated IC (custom IC), so that the degree of circuit integration can be further increased, the size and weight can be reduced, and the cost can be greatly reduced. . Furthermore, a more compact seat belt retractor control device has been realized, which can be mounted in a small vehicle that could not be mounted due to restrictions in the vehicle space, and can improve safety for passengers of small vehicles. it can.

The connection diagram of the collision safety device in vehicles. Crew restraint diagram for seats. The disassembled perspective view of a retractor control apparatus. FIG. 3 is a component layout diagram of a control circuit board. The block diagram of a control circuit. The overcurrent detection circuit diagram. The figure which shows a data storage destination. The connection relation figure of CPU and an external storage device. The figure which shows the update and deletion timing of stored data. The flowchart which shows the transfer procedure to sleep mode. Wake-up circuit diagram.

  Embodiments will be described below with reference to the drawings.

  First, FIG. 1 shows a connection diagram of a collision safety device in a vehicle. An obstacle sensor 12 that outputs a signal corresponding to the distance from the obstacle is attached to the vehicle 10 at the front part of the vehicle. The output signal of the obstacle sensor 12 is transmitted to the collision determination controller 14 that is electrically connected to the obstacle sensor 12. A signal from the wheel speed sensor 18 that outputs a signal corresponding to the speed of the vehicle is also transmitted to the collision determination controller 14 electrically connected to the wheel speed sensor 18. The collision determination controller 14 determines whether the vehicle 10 collides with an obstacle based on signals from the obstacle sensor 12 and the wheel speed sensor 18. For example, when the distance from the obstacle obtained from the output signal of the obstacle sensor 12 is shorter than a predetermined value and the vehicle speed obtained from the output signal of the wheel speed sensor 18 is higher than the predetermined value, The collision determination controller 14 determines that the vehicle 10 collides with an obstacle, and outputs a command signal to the brake assist device 16 and the seat belt drive controller 20 before the vehicle 10 collides with the obstacle.

  The brake assist device 16 and the seat belt drive controller 20 are electrically connected to the collision determination controller 14 and execute predetermined operations based on command signals from the collision determination controller 14, respectively. The seat belt drive controller 20 is electrically connected to the retractor 22 and controls power feeding to the retractor 22.

  FIG. 2 shows an occupant restraint diagram for the seat. The retractor 22 is provided with a motor 24. The rotation of the motor 24 enables the seat belt to be wound. For example, consider a case where the occupant 30 is driving the vehicle 10, but the occupant 30 moves slightly in the forward direction of the vehicle, and a gap is generated between the occupant 30 and the seat 28. In such a situation, when the vehicle 10 collides with an obstacle, the occupant is not restrained by the seat 28 and is strongly hit against the seat 28. However, according to the present system, the gap between the occupant 30 and the seat 28 is eliminated by operating the motor 24 attached to the retractor 22 and winding the seat belt 26 before the vehicle 10 and the obstacle collide. It is possible. Therefore, when the vehicle 10 and the obstacle collide, since the occupant 30 is already restrained by the seat 28, the impact on the occupant 30 can be reduced.

  According to FIGS. 1 and 2, the door switch 11 indicating the door open / close state and the buckle switch 13 indicating the seat belt buckle fastening state are electrically coupled to the seat belt drive controller 20 to drive the seat belt. The controller 20 periodically reads the on / off state of the door switch 11 and the buckle switch 13 or interrupts a CPU (not shown) included in the seat belt drive controller 20 when an on / off switch transition occurs. It is possible to read state transitions using. In addition, after the occupant 30 gets off, the seat belt drive controller 20 enters a low power consumption mode (hereinafter, sleep mode) in order to suppress the power consumption of the vehicle battery, but the state change of the door switch 11 and the buckle switch 13, etc. When the cause of the wake-up occurs, the seat belt drive controller 20 shifts from the sleep mode to the normal mode, and performs predetermined operations such as communication with other control devices mounted on the vehicle and the seat belt winding operation. Execute. The wake-up factor of the seat belt drive controller 20 may be CAN (Control Area Network) communication, K-Line communication, Lin (Local Interconnect Network) communication, or the like, or a combination thereof or any one of the factors. It may be set as an up factor.

  Further, the seat belt drive controller 20 illustrated in FIG. 1 may have an integrated structure with the retractor 22, and the present invention is not limited to the attachment position of the seat belt drive controller 20 and the retractor 22. .

  FIG. 3 is an exploded perspective view of the seat belt drive controller 20 used in this embodiment. On the circuit board 42, a connector 35 that carries power supply from the vehicle and communication with other control devices mounted on the vehicle and a dedicated IC (custom IC) 34 to be described later are mounted. The circuit board 42 is mounted with a protection element (not shown) for protecting circuit components such as a motor drive circuit (not shown) for driving the motor 24 and a custom IC 34 from overvoltage or reverse connection of the vehicle battery. Yes. The circuit board 42 is fastened by the cover 32 and screws 36, 38 and the like. The circuit board 42 and the cover 32 can be fastened not only by screw fastening but also by fastening with an adhesive or by fitting. The circuit board 42 and the cover 32 that are fastened to each other are fitted with the case 40, and the seat belt drive controller 20 is completed.

  In addition, referring to FIG. 3B, it can be seen that the circuit component is not mounted on the back surface of the circuit board 42, and is mounted on one side. This is one of the effects of adopting the custom IC 34, and circuit components are consolidated to enable single-sided mounting. As a result, it is possible to reduce the manufacturing cost by simplifying the mounting process such that the solder reflow process, the circuit component shortage, and the polarity inspection are completed on one side, that is, only once.

  In addition, the seat belt drive controller 20 can be conceived in which electronic components are also mounted on the back surface of the circuit board 42 to further reduce the size of the circuit board 42 and reduce the size.

  FIG. 4 shows a component layout of the control circuit board 42 used in this embodiment. When driving the command signal from the collision determination controller 14, power supply from the vehicle battery, input from the door switch 11 or the buckle switch 13, and the connector 35 and the motor 24 that communicate with other control devices mounted on the vehicle. Aluminum electrolytic capacitor 58 for suppressing generated conduction noise, MOSFET (46, 48, 50, 52) constituting a motor drive circuit for switching a power supply state to the motor 24, and current detection for converting a current supplied to the motor into a voltage A resistor 54, a custom IC 34 that controls the control function of the seat belt drive controller 20, an oscillator 56 that supplies a high-accuracy clock signal to the custom IC 34, and a control circuit board 42 when the vehicle battery is connected to the vehicle in a reverse polarity state Protective MOSFET 44 that protects the above circuit components from reverse voltage, It is mounted on the control circuit board 42 by conductive adhesive.

  FIG. 5A shows a block diagram of a control circuit in the conventional method. The control circuit in the conventional method includes a regulator 260 that supplies power to the control circuit during the sleep mode, a wakeup I / F 62 that detects that a wake-up factor has occurred and wakes up the regulator 1 64 that is the main power source, communication control, Power supplied to the motor 24 based on output signals of the PreDriver 88 and PreDriver 88 that convert the command signal of the CPU 82 that executes diagnosis and calculation processing of the motor control system into a drive signal to the MOSFET (46, 48, 50, 52) MOSFET 46, MOSFET 48, MOSFET 50, MOSFET 52, the motor 24 that converts electrical energy into rotational energy, the current detection resistor 54 that converts the current applied to the motor 24 into voltage, and the voltage generated by the current detection resistor 54 Amplified and transmitted to analog input of CPU82 Current Sense I / F 92, door switch 11 whose on / off state changes according to opening / closing of the door, buckle switch 13 whose on / off state changes according to fastening / release of the buckle, when the battery is reversely connected A protective element 44 that protects the electronic circuit, a sensor 70 and a sensor 72 that measure the amount of displacement of the vehicle brake and a seat belt, a regulator 36 that supplies predetermined power to the sensor 70 and the sensor 72, the sensor 70, A sensor I / F 68 that transmits the signal of the sensor 72 to the CPU 82, a communication I / F 74 that controls CAN communication, Lin communication, or K-Line communication with other control devices of the vehicle, and further, is different from the CPU 82. As IC, vehicle parameters, failure information of seat belt control device, door switch 11 or buckle State change switch 13, EEPROM 4 to store the motor control constants have been connected to the CPU 82. Each of these functions is mounted on a circuit board as a single IC, and the electrical connection that interacts with each other is realized by copper wiring generated on the circuit board. The line width and spacing of the copper wiring must be at least a certain distance to prevent short-circuiting due to ion migration, and the gap between the ICs is short between electrodes due to solder balls and the accuracy of the mounting machine component holding part There was a restriction such as that, it was necessary to leave a predetermined interval. In addition, in each IC, a bonding wire is used for connection between the bare chip and an external electrode such as a frame, and it is desirable as a seat belt control device because it is necessary to secure the bonding wire cost and the bonding area. It was difficult to achieve downsizing and cost reduction.

  FIG. 5B shows a control circuit block diagram of the seat belt drive controller 20 in the present embodiment. In the custom IC 34, the above-described regulator 2 60, wakeup I / F 62, regulator 1 64, regulator 3 66, sensor I / F 68, CAN (Lin) I / F 74, SW I / F 80, CPU 82, RAM 84, data retention even in the sleep mode Possible BackupRAM 84a, FlashROM1 86a for storing application software, FlashROM2 86b for storing vehicle parameters and control constants, FlashROM3a 86c and FlashROM3b 86d for storing failure information of seat belt control device, Current Sense I / F 92, pre-driver circuit and An overcurrent protection circuit 96 is formed on the same chip. The pre-driver circuit and the overcurrent protection circuit 96 measure the potential difference between the drain and source of the high-side MOSFET 46 and the high-side MOSFET 48, respectively, and measure the output of the current detection resistor 54. In the case of exceeding, the output of the pre-driver circuit is stopped and the MOSFET (46, 48, 50, 52) is turned off. In this embodiment, the CPU 82 is also mounted in the custom IC. However, the protection function is formed independently of the CPU 82, and the protection function is continuously effective even when the operation of the CPU 82 is stopped. Is possible.

  Further, the output terminal of the regulator 3 can be connected to the outside of the retractor control device, that is, the vehicle side, and the output terminal of the regulator 3 has a protection function against a short circuit with the vehicle battery or the vehicle housing.

  In addition, the sensor I / F 68 in the custom IC 34 has a pulse up / down count function in order to adapt to an encoder type sensor for detecting the rotation angle, such as a sensor for measuring the amount of seat belt retracted. Or two signals indicating the rotation direction and rotation amount can be directly input.

  Further, the SWI / F 80 inside the custom IC 34 has a function of causing the seat belt control device to transition from the sleep mode to the normal mode by the state transition of its input terminal.

  Further, the custom IC 34 is provided with a terminal that reflects the reset state of the custom IC 34. By measuring the potential of the custom IC 34, a reset state caused by an external cause such as a power supply voltage drop or an internal cause such as a software reset occurs. It is possible to confirm. This terminal also functions as an input terminal from the outside. When a GND potential is applied by an external circuit, the custom IC 34 has a function of resetting and transitioning the internal circuit to a reset state.

  Further, the custom IC 34 is provided with a terminal for connection to the AD conversion voltage stabilization capacitor 98 for voltage stabilization at the time of AD conversion, and this terminal is directly connected to the analog input terminal of the CPU 82. Therefore, the circuit design verification and software debugging work can be performed by measuring the potential with an external measuring device or the like. Further, in this custom IC 34, the overcurrent protection function functions independently of the CPU 82, the terminal potential is fixed in the normal range due to an internal failure or the like, the CPU 82 recognizes that it is normal, and continues to drive the motor. Even when the overcurrent occurs, the pre-driver circuit stops and the MOSFET can be safely turned off.

  Further, in the current sense I / F 92 of the custom IC 34, when the motor current is stopped, that is, at the time of 0 A, the output of the current sense I / F 92, that is, the AD conversion voltage stabilization capacitor 98 section is 0.5 V. It has a function of giving a certain offset potential. For this reason, the AD conversion voltage is stabilized when a failure occurs when the output of the Current Sense I / F 92 becomes the GND potential, that is, when a GND short-circuit failure of the internal circuit or an open failure occurs in the input terminal of the Current Sense I / F 92. Since the potential generated in the capacitor 98 is the GND potential, it can be distinguished from the normal state, and the CPU 82 can detect the failure.

  As described above, among the basic functions necessary for the seat belt drive controller 20, a function that does not require a steady current of 1 A or more is realized by one IC, and the mounting interval of a plurality of ICs, the copper wiring on the board, and the wires inside the IC Bonding and its area can be reduced, and the size of the seat belt drive controller 20 can be reduced.

  In addition, in the seat belt drive controller 20, the MOSFET 46, MOSFET 48, MOSFET 50, MOSFET 52, current detection resistor 54, reverse connection prevention circuit that switches the power supplied to the motor 24 outside the custom IC 34 and on the same circuit board 42. 44, an AD conversion voltage stabilization capacitor 98 is mounted. For this reason, not only the seat belt control device but also the application that requires more current, the MOSFETs 46, 48, 50, 52, the current detection resistor 54, and the reverse connection prevention circuit 44 have more current. By changing to the type having the capability, it is not necessary to change the custom IC, and the current capability can be improved simultaneously with the optimization of the circuit size.

  6A and 6B show functional blocks for overcurrent protection in this embodiment. In FIG. 6A, a CPU 82 and a watch dog timer (hereinafter referred to as WDT 102) for monitoring the operation of the CPU 82 are formed in the custom IC 34, and the CPU 82 always transmits a pulse signal (hereinafter referred to as a PRUN signal) to the WDT 102. is doing. When the operation of the CPU 82 is stopped and the PRUN signal is stopped, the WDT 102 causes the CPU 82 to generate a reset signal. At the same time, the WDT 102 also generates a reset signal for the pre-driver 88, stops the function of the pre-driver 88, and the MOSFETs 46, 48, 50, 52 are turned off. Further, comparators 108, 110, and 112 are installed inside the custom IC 34, the comparator 108 compares the drain-source potential difference of the high-side MOSFET 46, and the comparator 110 compares the drain-source of the high-side MOSFET 48. The comparator 112 compares the potential difference generated at both ends of the current detection resistor 54. Here, the drain-source potential difference between the high-side MOSFET 46 and the high-side MOSFET 48 is the product of the drain current flowing through the MOSFET 46 or MOSFET 48 and the on-resistance of the MOSFET 46 or MOSFET 48. For this reason, as the current increases, the drain-source potential also increases, and when the overcurrent occurs, the threshold of the comparator is exceeded. Furthermore, the comparison results of the respective comparators are transmitted to the OR circuit 114, and if any of the comparators exceeds the threshold and is determined to be an overcurrent, the pre-driver 88 is stopped. In addition, an external switch 120 is connected to the pre-driver 88, and the pre-driver 88 is forcibly set regardless of the processing contents of the custom IC 34 by setting the switch to the fastening state (GND potential) in the external circuit. Can be stopped and the MOSFETs 46, 48, 50, 52 can be turned off. Further, the potential difference of the current detection resistor 54 is also transmitted to the amplifier 116, processed with a predetermined amplification factor, and then added with the offset voltage 118 generated by the offset voltage generation unit 118, and the analog input unit of the CPU 82. Is transmitted to. The amplification and addition results are output to the connection terminal to the external capacitor 98 and can be measured by an external device. Here, the comparator 108, the comparator 110, the comparator 112, and the OR circuit 114 function independently of the CPU 82. For example, even when the operation of the CPU 82 is stopped, the input potential difference to the comparator is different. If it exceeds the predetermined value, the pre-driver 88 can be stopped.

  FIG. 6B shows a functional block for overcurrent protection in another method of this embodiment. The current detection resistor 122 is connected to the upper stage of the high-side MOSFETs 46 and 48, and the voltage between both ends thereof is connected to the comparator 108 in the custom IC 34. When the current value increases and the potential difference generated in the current detection resistor 122 exceeds a predetermined value, the comparator 108 can react and stop the pre-driver circuit 88. According to this method, since the current value to be interrupted can be determined by the resistance value of the current detection resistor 122 regardless of the ON resistance of the MOSFET having a large temperature change, the protection circuit can be realized with higher accuracy. Become.

  FIG. 7A shows a data storage destination in the conventional method. In the conventional method, the Flash ROM 86 is provided on the same chip as the CPU 82, and BootCode 124 and Application Software 126 are stored in the Flash ROM 86. Further, data that is frequently changed and data that needs to be updated while the vehicle is running are stored in an EEPROM 94 that is another IC. For example, parameters for motor control (MotorControlParameters) 128, vehicle model information (Vhiecle Parameters) 130, failure diagnosis information (DiagnosticTroubleCode) 132, ECU wake-up frequency, and ECUStatus134 indicating the on / off state of the door switch 11 or the buckle switch 13 Corresponds to the data. In this method, the Flash ROM 86 in which the application is stored and the EEPROM 94 in which the above-described data are stored are configured as separate ICs. Therefore, data communication between the CPU 82 and the EEPROM 94 is independent of the Flash ROM 86 and there is no data interference. The CPU 82 can erase and update the data in the EEPROM 94 at any time while executing the software stored in the Flash ROM 86. is there. However, it is necessary to mount the EEPROM 94 as an IC separate from the CPU 82 on the circuit board, which is an obstacle to downsizing and cost reduction of the control device.

  FIG. 7B shows a data storage destination in this embodiment. In the custom IC 34, a Flash ROM 186a is formed on the same chip as the CPU, and BootCode 124 and Application Software 126 are stored. On the same chip, Flash ROM 286b is formed, and MotorControlParameters 128 and Vhiecle Parameters 130 are stored. Has been. The BootCode 124, the Application Software 126, the MotorControlParameters 128, and the Vhiecle Parameters 130 do not need to be changed in the vehicle running state after being written on the control device production line. For this reason, even if the data update operation fails, the data update operation can be performed. Since redoing is allowed, one area (124, 126, 128, 130) is assigned.

  On the same chip, the FlashROM 3a 86c and the FlashROM 3b 86d store a Diagnostic TroubleCode 132 and an ECUStatus1 134 indicating the number of times the ECU has been woken up. These DiagnosticTroubleCode 132 and ECUStatus1 134 need to be updated while the vehicle is running, and the update operation is not allowed to be performed again. Therefore, by updating each of the areas of FlashROM 3a 86c and FlashROM 3b 86d, the data is updated. If this fails, the data in the other area is validated, and the reliability is further improved. Further, a backup RAM 84a capable of holding data even in the sleep mode is formed on the same chip, and information on the door switch 11 and the buckle switch 13 is stored. Since the state of these switch information frequently changes, the backup RAM 84a, which has no limit on the number of data updates, is optimal as a storage destination.

  FIG. 8A shows a connection relationship between the CPU and the external storage device in the conventional method. In the conventional method, a storage device such as an EEPROM 86 is arranged as an external component in addition to the CPU 82. Further, a plurality of signal lines are required for connection between them, and they are formed by a copper pattern on the control circuit board.

  FIG. 8B shows a connection relationship between the CPU and the internal storage device in the conventional method. In the conventional method, the connection between the CPU 82 and the storage device (Flash) 86 is an internal connection, but they are connected by different memory buses and data buses 136, respectively. As a result, the area occupied on the chip is increased, and the influence on other functions such as an increase in the chip size or a storage capacity limit of the storage device is considered.

  FIG. 8C shows a connection relationship between the CPU and the internal storage device in this embodiment. In this embodiment, the CPU 82 and the internal storage device 86 are connected by a single memory bus and data bus 136. For this reason, the chip size can be reduced, and the control circuit can be downsized.

  FIG. 9 shows the update and erase timing of stored data in this embodiment. In this embodiment, the CPU 82 and the internal storage device 86 are connected by a single memory bus and data bus 136, and the erasing operation of the storage device usually takes about several seconds. This erase operation means that the memory bus and the data bus 136 are occupied, and the execution of the application software is stopped during that time. This is not allowed in a seat belt retractor control device that requires real-time performance. For this reason, in this embodiment, as shown in FIG. 9, in the transition period from the normal mode to the sleep mode (sleep mode transition period), the data erasing operation of the storage device is executed if necessary.

  Next, the power supply wake-up and shut-off sequence of the control device is shown. After the power supply VB rises, the VCC is woken up by the internal power supply (Regulator 1) 64, and the boot software 124 and application software 126 stored on the Flash ROM 186a are woken up. The CPU 82 executes application software 126 on the Flash ROM 1 to realize functions necessary for the seat belt drive controller 20. Here, when the conditions for shifting to the sleep mode are satisfied due to the occupant 30 getting off, stopping the operation for a certain period of time, stopping CAN communication, or the like, the mode shifts to the sleep mode transition period, and the CPU 82 stores data in a RAM (not shown). The necessary software is transferred, and if necessary, the FlashROM 3a 86c or FlashROM 3b 86d is erased, and the data in the FlashROM 3a 86c or FlashROM 3b 86d is updated. During this period, the execution operation of the application software stored on the Flash ROM 186a operating in the normal mode is stopped for a few seconds, and the program is operating on the RAM. Also during this period, the WDT functions and it is necessary to periodically output the PRUN signal from the CPU 82 to the WDT as in the normal mode. In this case, the timing generated by the normal timer interrupt cannot be used and depends on the software periodicity, so the period of the PRUN signal may be different from that in the normal mode. Also during this period, if a wake-up factor such as opening / closing of a door, fastening / opening of a buckle switch, or restart of CAN communication occurs again, the software on the RAM monitors the occurrence state of the wake-up factor. The operation can be continued with the software operating on the RAM and the control can be switched to the application software operating on the Flash ROM. Therefore, the CPU 82 can be returned to the normal mode without being reset. After the necessary operation such as data erasure is completed, the CPU 82 cuts off the internal VCC power supply and enters the sleep mode, and suppresses the current consumption as a control device to 100 μA or less (however, 25 ° C.).

  Also, when data is erased during this period, all bits are erased to 1 after 0 is written to all bits of the FlashROM. If the power supply VB is cut off during this period, the data in the Flash ROM may have changed to unintended data, and the reliability of the data is confirmed by a checksum or the like.

  FIG. 10 is a flowchart showing a procedure for shifting to the sleep mode according to the present embodiment. During normal mode, it is confirmed 140 that sleep mode transition conditions such as passenger disembarkation and CAN communication are periodically met. When the sleep mode transition conditions are satisfied, the flash ROM data is updated via wakeup factor determination 142. Condition satisfaction determination 144 is executed. If it is determined in the flash ROM data update condition establishment determination 144 that the data needs to be updated, the data is stored in a predetermined area. Furthermore, if it is determined in the flash ROM erasure condition establishment determination 148 that the data in the flash ROM needs to be erased, the data in a predetermined area is erased. Next, an erasure completion determination is performed to determine the completion of the erasure operation that is normally continued for several seconds. To deal with the occurrence of a wake-up factor during erasure, the wake-up factor occurrence determination is periodically executed. If a wake-up factor such as CAN communication occurs, the status is confirmed by software. Return to normal mode. During this period, the operation of the CPU 82 is executed by software on the RAM, and it is possible to return to the normal mode within 10 msec by monitoring the wake-up factor flag with the software on the RAM.

  As described above, various data can be stored in the custom IC 34 without using an external IC, and the control device can be downsized.

  FIG. 11A shows a wake-up circuit diagram in the conventional method. There are CAN communication, Lin or K-Line communication, buckle switch input, door switch input, and ignition SW input as wakeup factors, and edge detection circuits (158a to 158e) for detecting the rising and falling of the signal are connected. Has been. These edge detection circuits (158a to 158e) need to function continuously even in the sleep mode, and are always supplied with power. The outputs of these edge detection circuits (158a to 158e) are connected to the one-shot pulse generator 162 via the logic unit 160, and become a wake-up factor for the main power supply regulator 164. When the main power supply 64 wakes up, the CPU 82 starts operation. After the operation of the CPU 82 starts, the CPU 82 supplies the Alive number to the Regulator 1 64 within the pulse generation duration of the one-shot pulse generator 162, and the Regulator 1 64 is fixed to the wake-up state and is generated by the one-shot pulse generator 162. Even after the pulse signal becomes invalid (Low potential), the power supply 5V necessary for the operation of the CPU 82 is secured. Further, the CPU 82 confirms the respective terminal potentials and the output of the edge detection circuit via the wakeup factor I / F circuit 160 in order to determine the wakeup factor. In order to realize the above functions, in the conventional method, each function is realized by an individual IC, and reduction of the mounting area has been a problem. In addition, in order to switch the validity / invalidity of the wakeup factor by mounting / not mounting the edge detector, in the same application, only a time-invariant system can be constructed, and switching during vehicle running is possible. It was impossible to respond.

  FIG. 11B shows a wake-up circuit diagram in this embodiment. In the present embodiment, the edge detection circuit, the pulse generator, and the wakeup factor I / F circuit are formed in the same custom IC 34, and the CPU 82 is also formed on the same chip. The control circuit board can be reduced in size.

  FIG. 11C shows an internal configuration diagram of a wake-up circuit diagram in this embodiment. As wake-up factors, there are CAN communication, Lin or K-Line communication, buckle switch input, door switch input, and ignition SW input, and switches (168a to 168e) for switching between valid and invalid of the signal are connected. The wake-up factor selection circuit 164 is supplied with power from the Regulator 260 and has an electrical connection with the CPU 82. For this reason, it is possible to select the wake-up factor from the CPU 82 before entering the sleep mode. For example, when entering the sleep mode with the buckle fastened, it is not necessary to open / close the door but to release the buckle. The wake-up factor can be switched in a state where the control circuit is mounted on the vehicle. The generated wake-up factor is stored in the memory, and the CPU 82 can determine the wake-up factor by accessing the memory after wake-up. This memory can hold data even during sleep, and a backup RAM can be considered as an example. In addition, since the wakeup control circuit 166 enables the regulator 1 64 after the wakeup factor is generated, it is not necessary to generate the above-described alive signal from the CPU 82, and the wakeup process of the CPU 82 is simplified.

DESCRIPTION OF SYMBOLS 10 Vehicle 11 Door switch 12 Obstacle sensor 14 Collision judgment controller 16 Brake assist device 18 Wheel speed sensor 20 Seat belt drive controller 22 Retractor

Claims (8)

In a vehicle seat belt, an actuator that can drive the seat belt in a winding direction and a feeding direction, and a seat belt retractor control device that controls the actuator,
The control device includes a control arithmetic circuit provided in the control device;
A circuit for communicating with equipment outside the control device,
A seat belt retractor control device comprising a power supply circuit for supplying power for the arithmetic circuit using one dedicated IC. In a vehicle seat belt, an actuator that can drive the seat belt in a winding direction and a feeding direction, and a seat belt retractor control device that controls the actuator,
The control device includes a control arithmetic circuit provided in the control device;
A circuit for communicating with a device outside the control device;
A circuit for starting the control device,
A seatbelt retractor control device comprising a power circuit for an arithmetic circuit using one dedicated IC. A vehicle seat belt, a sensor mechanism attached to the seat belt or the vehicle, an actuator capable of driving the seat belt in a winding direction and a feeding direction, and a seat for controlling the actuator based on a signal of the sensor mechanism In the belt retractor control device,
The control device
The control device includes a control arithmetic circuit provided in the control device, and a sensor power supply circuit for supplying power to the sensor mechanism,
A seat belt retractor control device comprising the sensor power supply circuit having a ground fault and a power fault protection function using one dedicated IC. Based on a vehicle seat belt, an angle sensor mechanism for measuring a winding amount or a feeding amount of the seat belt, an actuator capable of driving the seat belt in a winding direction and a feeding direction, and a signal from the angle sensor mechanism, In the seat belt retractor control device that controls the actuator,
The control device includes a control arithmetic circuit provided in the control device,
A seatbelt retractor control device comprising an arithmetic circuit for processing a signal of the sensor mechanism and a single dedicated IC.   The seat belt retractor control device according to any one of claims 1 to 4, wherein a terminal that reflects a reset state of the dedicated IC is provided in the dedicated IC.   The seat belt retractor control device according to any one of claims 1 to 4, wherein a terminal that reflects an AD (analog / digital) conversion value in the dedicated IC is provided in the dedicated IC.   The seat belt retractor control device according to any one of claims 1 to 4, wherein a plurality of storage devices are provided inside the dedicated IC. Having a function of measuring the current generated in the actuator;
Having a terminal whose voltage changes according to the current;
The seatbelt retractor control device according to any one of claims 1 to 4, wherein a positive voltage is generated at the terminal even when the current is zero amperes.

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