JPH1035407A - Side air bag controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To use a backup power source in common for a left side controller and a right side controller arranged in compliance with side air bags on the left side and the right side in a side air bag controller. SOLUTION: A right side ECU 14 controlling an action of a right side air bag arranged on the vehicle right side is arranged on the right side face of a vehicle. A left side ECU 22 controlling an action of a left side air bag arranged on the vehicle left side is arranged on the left side face of the vehicle. A backup power source constructed of a pressure increasing circuit 72 and a backup circuit 74 is arranged in the right side ECU 14. In the left side ECU 22, any element serving as a constitutional element of a pressure increasing circuit nor any element serving as a constitutional element of a backup circuit is not mounted. A Vreg line 64 of the right side ECU 14 and a Vreg line 150 of the left side ECU 22 are connected together via a power source connection line 24.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a side airbag control device, and more particularly to a side airbag control device suitable for controlling the operation of a side airbag mounted on a vehicle.

[0002]

2. Description of the Related Art Conventionally, for example, Japanese Utility Model Laid-Open Publication No. 1-17995.
7, JP-A-6-1035 and JP-A-5-9373.
As disclosed in No. 5, a side airbag is known. The side airbag is a safety device provided to absorb energy input from the side of the vehicle. The side airbag is housed, for example, on the side of a seat, and when energy exceeding a predetermined value is input to the vehicle from the side, the side airbag expands to absorb the energy.

[0003] Energy input from the side of the vehicle reaches the vehicle interior in a shorter time than energy input from the front of the vehicle. Therefore, the side airbag system is required to have higher responsiveness than an airbag for absorbing energy input from the front of the vehicle (hereinafter, this airbag is referred to as a front airbag). In order to ensure high responsiveness in the airbag system, it is effective to detect the magnitude of the input energy in the vicinity of the part where the energy is input.

The above-described conventional side airbag system includes a right acceleration sensor provided on a right side of a vehicle and a left acceleration sensor provided on a left side of the vehicle. As described above, when the acceleration sensors are disposed on the left and right side surfaces of the vehicle, the magnitude of the energy input from the right side of the vehicle and the magnitude of the energy input from the left side of the vehicle are improved. It is possible to detect with high accuracy under the responsiveness. Therefore, according to the conventional side airbag system, the side airbag can be operated with high responsiveness.

[0005] The signal output from the acceleration sensor is generally a weak signal that is easily affected by noise. For this reason,
It is desirable that the acceleration sensor and the control circuit that processes the signal of the acceleration sensor be close to each other. Therefore, when the acceleration sensors are disposed on the left and right sides of the vehicle, the control circuit for the right side airbag and the control circuit for the left side airbag are separately configured, and are respectively disposed on the left and right sides of the vehicle. It is desirable.

[0006]

By the way, in the front airbag system, a backup power supply is mounted on the front airbag control device in preparation for damage to the battery, disconnection of the wire harness, and reduction of the battery voltage. That is being done. If the backup power supply is mounted on the control device in this manner, the front airbag can be operated properly even if a situation occurs in which sufficient power cannot be supplied from the battery to the control device due to input of energy to the vehicle. Can be.

[0007] In the side airbag system,
With the input of energy to the vehicle, a situation may arise in which sufficient power cannot be supplied from the battery to the control circuit of the side airbag. Therefore, when the control circuits are disposed on the left and right side surfaces of the vehicle as described above, it is conceivable to incorporate the backup power supplies into the control circuits.

[0008] However, the right side airbag and the left side airbag are not simultaneously expanded.
Therefore, even if the backup power supply is shared by the left and right control circuits, no substantial inconvenience occurs. Furthermore, if the backup power supply is shared by the left and right control circuits, the number of parts and the number of assembling steps can be reduced as compared with the case where the backup power supply is provided for each of the left and right control circuits.

The present invention has been made in view of the above points, and provides a side airbag control device in which left and right control circuits for controlling the operation of the left and right side airbags share a backup power supply. With the goal.

[0010]

The above object is achieved by the present invention.
As described in the above, a right control device that controls the operation of the right side airbag disposed on the right side of the vehicle, and a left control device that controls the operation of the left side airbag disposed on the left side of the vehicle, In the side airbag control device provided, one of the right control device and the left control device has a backup power supply, and a power supply system of the right control device and a power supply system of the left control device have a power supply connection line. This is achieved by a side airbag control device connected via a.

In the present invention, the operation of the right side airbag is controlled by the right control device. The operation of the left side airbag is controlled by the left control device. The power supply system of the right control device and the power supply system of the left control device are connected via a power supply connection line. Therefore, the power supplied by the backup power supply can reach both the right control device and the left control device. Thus, the backup power supply is shared by the right control device and the left control device.

[0012]

FIG. 1 is a system configuration diagram of a side airbag system according to an embodiment of the present invention. FIG. 2 is a block diagram showing an electrical configuration of the side airbag system according to the present embodiment.

The side airbag system of the present embodiment has a battery 10. As shown in FIG.
Reference numeral 0 communicates with a right electronic control unit 14 (hereinafter, referred to as a right ECU 14) via a junction box 12. As shown in FIG. 2, the battery 10 and the right ECU
14, an ignition switch 16 (hereinafter referred to as an ignition switch).
IG switch 16) is interposed.

The IG switch 16 and the right ECU 14
Are connected by an IGN line 18 and an ACC line 20. The IG switch 18 brings the battery 10 and the ACC line 20 into conduction by setting the ignition key to the ACC position. The IG switch 18 brings the battery 10 and the IGN line 18 into conduction by turning the ignition key to the ON position.

The right ECU 14 is connected to a left electronic control unit 22 (hereinafter referred to as a left ECU 22). A power supply connection line 24 is provided between the right ECU 14 and the left ECU 22. Power connection line 24
Is used as a line for supplying power from the right ECU 14 to the left ECU 22.

A communication line 26 is provided between the right ECU 14 and the left ECU 22. Communication line 26
Is used when information is exchanged between the right ECU 14 and the left ECU 24. Right ECU 14 and left ECU
22, a GND line 28 is provided.
The right ECU 14 is body-grounded by connecting its GND system to the vehicle body. Left ECU 22
Is grounded via the GND line 28 and the right ECU 14.

A warning lamp 30 is connected to the right ECU 14. The right ECU 14 detects the abnormality of its own,
When a signal indicating an abnormality of U22 is input, a warning lamp is turned on. The right ECU 14 is provided with a Tc terminal 31. Right ECU 14 and left EC
U22 has a function of storing an abnormal state generated during its operation. Right ECU 14 and Left ECU 22
Outputs a code signal corresponding to the stored abnormal state when the Tc terminal 31 is grounded.

A right side airbag module 32 is connected to the right ECU 14. The right side airbag module 32 is housed near the right lumbar support of the right front seat 33. The right side airbag module 32 includes a squib 34 together with a side airbag folded to a predetermined size and an inflator for supplying inflation gas to the side airbag.

The right ECU 14 supplies a predetermined current to the squib 34 when energy exceeding a predetermined value is input to the vehicle from the right side of the vehicle. Squibb 34
When the predetermined current is supplied, the inflator is ignited, and the side airbag of the right front seat 33 is expanded.

A left side airbag module 36 is connected to the left side ECU 22. The left side airbag module 36 is housed near the left lumbar support of the left front seat 38. The left side airbag module 36 includes a squib 40 together with a side airbag folded to a predetermined size and an inflator for supplying inflation gas to the side airbag.

The left ECU 22 supplies a predetermined current to the squib 40 when energy exceeding a predetermined value is input to the vehicle from the left side of the vehicle. Squibb 40
Then, when the predetermined current is supplied, the inflator is ignited, and the side airbag of the left front seat 38 is expanded.

The energy input to the vehicle from the side of the vehicle is
It reaches the vehicle interior in a short time compared to the energy input from the front of the vehicle. Therefore, it is necessary to expand the side airbag earlier than the front airbag after energy starts to be input to the vehicle. For this reason, a control device for the side airbag is required to have better responsiveness than a control device for the front airbag.

In order to ensure excellent responsiveness in the control device for the side airbag, it is desirable to arrange a sensor for detecting the energy input to the vehicle in the vicinity of the portion where the energy is input. In the present embodiment, the right ECU 14 and the left ECU 22 are housed inside the center pillar 42 on the right side of the vehicle and inside the center pillar 44 on the left side of the vehicle, respectively. Also, the right side E
Each of the CU 14 and the left ECU 22 is equipped with an acceleration sensor for detecting energy input to the vehicle from the right side and an acceleration sensor for detecting energy input to the vehicle from the left side.

According to the above configuration, the energy input to the vehicle from the right side is accurately detected by the acceleration sensor built in the right ECU 14. The energy input to the vehicle from the left side is accurately detected by an acceleration sensor built in the left ECU 22.

The signal output from the acceleration sensor is a small signal. Therefore, the output signal of the acceleration sensor is easily affected by noise. As in this embodiment,
If the acceleration sensor is mounted on the right ECU 14 or the left ECU 22, the transmission distance until the signal is processed can be made sufficiently short. The output signal of the acceleration sensor is less affected by noise as the transmission distance is shorter. Therefore, according to the control device of the present embodiment, the influence of noise superimposed on the output signal of the acceleration sensor can be sufficiently suppressed.

When a large amount of energy is input to the vehicle, the battery 10 may be damaged due to the input, or the wire harness from the battery 10 to the right ECU 14 may be damaged, so that power cannot be supplied to the right ECU 14. When the capacity of the battery 10 decreases,
In some cases, predetermined power cannot be supplied to the right ECU 14. In the front airbag system, a method of incorporating a backup power supply in the control device has been widely used in order to enable the front airbag to be expanded even in a case where power cannot be supplied to the control device as described above. I have.

As described above, the system of this embodiment supplies power to the left ECU 22 through the right ECU 14. Therefore, when sufficient power cannot be supplied from the battery 10 to the right ECU 14, a situation occurs in which appropriate power cannot be supplied not only to the right ECU 14 but also to the left ECU 22. For this reason, in the system of the present embodiment, the right ECU 14 and the left ECU
It is conceivable that a backup power supply is built in both of them.

However, the system of this embodiment is a system in which, when energy is input from the side of the vehicle, only the side airbag disposed in the direction in which the energy is input is expanded. Accordingly, there is no need to simultaneously open the right side airbag and the left side airbag.

If it is not necessary to simultaneously expand the right side airbag and the left side airbag, the backup power supply can be shared by the right ECU 14 and the left ECU 22. For this reason, in the system of this embodiment, the backup power supply is mounted only on the right ECU 14 and
The CU 22 is supplied with power from a backup power supply mounted on the right ECU 14.

Hereinafter, referring to FIGS. 3 to 5, the right EC
The configuration of the U14 and the left ECU 22 will be described.
3 and 4 are circuit diagrams of the right ECU 14, respectively.
2 shows a circuit diagram of the left ECU 22. In this embodiment, the circuits shown in FIGS. 3 and 4 are configured on a common printed wiring board (hereinafter, referred to as PWB).

FIG. 5 shows a part of the PWB 45 (hereinafter, referred to as right PWB 45) used in the right ECU 14 and a part of the PWB 46 (hereinafter, referred to as left PWB 46) used in the left ECU 22. In this embodiment, the backup power supply is provided only in the right ECU 14 as described above. FIG. 5 shows a portion of the right PWB 45 that constitutes a backup power supply and a left PWB corresponding to the portion.
WB 46 is shown.

[0032] As shown in FIG.
A C terminal 47 and an IG terminal 48 are provided. The ACC terminal 47 is connected to a positive terminal of the battery 10 via a switch 50 which is a component of the IG switch 16. The IG terminal 48 is connected to a positive terminal of the battery 10 via a switch 52 which is a component of the IG switch 16.

The ACC terminal 47 and the IG terminal 48 are connected to a diode circuit 54. Diode circuit 5
4 has four diodes 56 to 62 as shown in FIG. The cathode terminals of the diodes 56 and 58 are
Both are power supply lines 64 (hereinafter referred to as Vreg lines 64)
It is connected to the. These diodes 56, 58
When a high potential is generated at at least one of the ACC terminal 47 and the IG terminal 48, an OR circuit for transmitting the potential to the Vreg line 64 is formed.

The right ECU 14 has a VBUI terminal 66 and a VBUO terminal 68. Both the VBUI terminal 66 and the VBUO terminal 68 are connected to the Vreg line 64
It is connected to the. In the right ECU 14, VBUI
The terminal 66 is in an open state. On the other hand, the left ECU 2 is connected to the VBUO terminal 68 via a connector (not shown).
2 is connected.

The diode 6 included in the diode circuit 54
The cathode terminals 0 and 62 are both connected to the booster circuit 72. These diodes 60 and 62 form an OR circuit that transmits a high potential to at least one of the ACC terminal 47 and the IG terminal 48 to the booster circuit 72.

The booster circuit 72 is a circuit that outputs a voltage of about 15 V when a battery voltage is supplied to its input terminal. The output terminal of the booster circuit 72 is connected to the Vreg line 64. The booster circuit 72 is provided to output an appropriate voltage to the Vreg line 64 when the battery voltage drops. The operation of the booster circuit 72 requires some power consumption.

A backup circuit 74 is connected to the Vreg line 64. As shown in FIG. 5, the backup circuit 74 includes a resistor 76, a backup capacitor 78, and a diode 80. The resistance 76 is Vreg
It is interposed between the line 64 and the backup capacitor 78. The diode 80 is interposed between the Vreg line 64 and the backup capacitor 78 so that a current can flow from the backup capacitor 78 toward the Vreg line 64. The backup capacitor 78 is grounded at one electrode. The other electrode of the backup capacitor 78 is connected to the resistor 76 and the diode 80 as described above, and to the Vc line 82 for outputting the charging potential Vc.

As shown in FIG. 3, the Vreg line 64 includes:
An ignition circuit 86 is connected via a resistor 84. The ignition circuit 86 is constituted by an FET element. The Vreg line 64 is connected to the drain terminal of an ignition circuit 86 via a resistor 84. The right ECU 14 controls the squib 3
4 and a negative output terminal 90 (hereinafter referred to as F + terminal 88).
R-terminal 90). The source terminal of the ignition circuit 86 is connected to the FR + terminal 88.

A safing sensor 92 is connected to the FR-terminal 90. The safing sensor 92 is a mechanical acceleration sensor. Safing sensor 92
Is turned on when an acceleration having a component exceeding a predetermined value acts on the right ECU 14 in a predetermined direction.

The safety circuit 9 includes a safety circuit 9.
4 are connected. The safety circuit 94 is constituted by an FET element. The safing sensor 92 is connected to the drain terminal of the safety circuit 94. The source terminal of the safety circuit 94 is connected to the GND line 95. G
The ND line 95 is connected to the first ground terminal 96 of the right ECU 14.
(Hereinafter referred to as E1 terminal 96) and second ground terminal 97.
(Hereinafter referred to as E2 terminal 97).

The right ECU 14 has a CPU 100. CPU 100 is supplied with power from Vreg line 64. An EEPROM 102 as a non-volatile primary memory is connected to the CPU 100. CPU 100
Writes the data to be stored irrespective of whether power is supplied, for example, a history of an abnormality detected by the right ECU 14 into the EEPROM 102.

The gate terminal of the safety circuit 94 is connected to the CPU 100. Further, the CPU 100 is connected to an acceleration sensor 104 for detecting acceleration generated in the vehicle when energy is input to the vehicle from the right side. CPU 100 turns on safety circuit 94 when it is determined based on the output signal of acceleration sensor 104 that energy exceeding a predetermined value has been input from the right side of the vehicle.

The CPU 100 is connected to a Vc line 82 connected to the backup capacitor 78. CP
U100 detects the charging voltage Vc of the backup capacitor 78 via the Vc line 82, and determines whether the backup capacitor 78 is functioning normally based on the detected value.

The right ECU 14 has an ignition control circuit 108. In addition, the ignition control circuit 108
12 are provided. The ignition control circuit 108 controls the ignition circuit 8
6 is connected to the gate terminal. Ignition control circuit 108
Turns on the ignition circuit 86 when it is determined that energy exceeding a predetermined value is input from the right side of the vehicle, and controls the state of the ignition circuit 86 detected by the inhibition circuit 112.

A latch circuit 114 is connected to the prohibition circuit 112. 5V power supply IC
116 is connected. The 5V power supply IC 116 has C
A watchdog terminal (hereinafter, referred to as a WD terminal) and a reset terminal of the PU 100 are connected. CPU10
A watchdog pulse (hereinafter, referred to as WDP) is always output to the WD terminal of 0 at a predetermined period while the CPU 100 is operating.

The 5V power supply IC has a function of converting the power supply voltage Vreg to a 5V voltage, and a WD of the CPU 100.
When the normal WDP is not output to the terminal, the CPU
100 is provided with a function of determining that an abnormality has occurred and transmitting a reset signal to its reset terminal. When detecting an abnormality in CPU 100 based on WDP, 5V power supply IC 116 supplies the abnormality to latch circuit 114. The latch circuit 114 latches an abnormal signal transmitted from the 5V power supply IC 116. Prohibition circuit 112
Prohibits the ignition control circuit 108 from outputting an ON signal to the ignition circuit 86 when the latch circuit 114 latches the abnormality signal indicating the abnormality of the CPU 100. For this reason, in the right ECU 14, the CPU 1
When an abnormality occurs in 00, the ignition circuit 86 is not accidentally turned on.

The right ECU 14 also operates the comparator 1
20. The comparator 120 has two input terminals, a bias power supply 122 and a DSO terminal 12.
4 is connected. The bias power supply 122 is a constant voltage source that generates a half of the power supply voltage Vreg. The DSO terminal 124 is a terminal that receives supply of a pulse signal according to an abnormal state of the left ECU 22 from the left ECU 22 via a connector (not shown). The comparator 120 converts the pulse signal supplied to the DSO terminal to 0-
The signal is converted into a pulse signal of 5V and supplied to the CPU 100.
The CPU 100 determines whether the left ECU 22 is operating normally based on the output signal of the comparator 100.

The CPU 100 also has one terminal Vba connected between the booster circuit 72 and the diode circuit 54.
The tt line 125 is connected. Vbatt line 125
Supplies the battery voltage Vbatt to the CPU 100 via the diode circuit 54. CPU 100 determines whether battery 10 is generating an appropriate voltage based on battery voltage Vbatt.

The right ECU 14 controls the lamp drive circuit 12
6 and a lamp disconnection detection circuit 128.
The lamp drive circuit 126 includes an L
Two terminals 130 are connected. The right ECU 14
Further, an SLA terminal 132 connected to the warning lamp 30 and an L1 terminal 134 connected to the SLA terminal 132 are provided. The L2 terminal 130 is connected to the L1 terminal 1 by properly fitting a connector (not shown).
34.

When the L1 terminal 134 and the L2 terminal 130 are properly fitted and the warning lamp 30 is not disconnected, the power supply voltage Vreg is supplied to the lamp driving circuit 126.
Is led. In other words, when the power supply voltage Vreg is not guided to the lamp driving circuit 126, it can be determined that the connector is not properly fitted or the warning lamp 30 is disconnected.

The lamp driving circuit 126 has an L2 terminal 130
When the power supply voltage Vreg is not supplied from the controller, a predetermined electric signal is output to the lamp disconnection detection circuit 128 to indicate that the above-described abnormality has occurred. The lamp disconnection detection circuit 128 is connected to the CPU 100. The lamp disconnection detection circuit 128 transmits an abnormal signal to the CPU 100 when the above signal is supplied from the lamp drive circuit 126. The CPU 100 includes a lamp disconnection detection circuit 1
When an abnormality signal is supplied from 28, the history of the abnormality is recorded in the EEPOM 102 so that the occurrence of the abnormality is recorded.

The lamp driving circuit 126 includes a latch circuit 1
14 and an abnormal signal output from the CPU 100 are supplied. When a signal indicating the occurrence of some abnormality is transmitted from the latch circuit 114 or the CPU 100, the lamp driving circuit 126
Is lowered to the ground level. When the L2 terminal 130 reaches the ground level, current starts to flow through the warning lamp 30, and the warning lamp 30 is turned on.

The right ECU 14 controls the TC terminal buffer 13
6 is provided. The TC terminal buffer 136 is connected to the right EC.
It is connected to the TC terminal 31 of U14 and the CPU 100. The TC terminal buffer 136 is configured by a comparator. The TC terminal buffer 136
When the potential of the C terminal 31 is lower than a predetermined threshold, CP
A low level signal is supplied to U100. Also,
When the potential of the TC terminal 31 is maintained at a potential exceeding a predetermined threshold, the TC terminal buffer 136
A high level signal is supplied to U100. When a low-level signal is supplied from the TC buffer 136 to the CPU 100, the diagnosis data stored in the EEPROM 102 can be read.

The right ECU 14 has an E1 terminal 96 and an E1 terminal.
A second GND line 138 connected to the two terminals 97 is provided. The second GND line 138 is connected to the E3O terminal 140
It is connected to the. The E3O terminal 140 is connected to a GND terminal of the left ECU 22 via a connector (not shown).

Next, the configuration of the left ECU 22 will be described. As shown in FIG. 5, the left ECU 22 includes an ACC terminal 142 and an IG terminal 144. Left ECU
22 is an ACC terminal 142 and an IG terminal 144
Are used in a state where both are opened. Therefore, the left EC
No power is directly supplied to U22 from the battery 10.

The left ECU 22 has a VBUI terminal 146 and a VBUO terminal 148. VBUI terminal 1
46 and VBUO terminal 148 are both connected to Vreg line 1
50. The VBUO terminal 148 is used in an open state. On the other hand, the VBUI terminal 146 is connected to the VBUO terminal 68 of the right ECU 14 via the power supply connection line 24 via a connector (not shown). Therefore, the Vreg line 150 includes the Vre of the right ECU 14.
A voltage equivalent to g line 64 is derived.

The left PWB 4 which is a substrate of the left ECU 22
6, Vbatt lines 125 corresponding to the Vbatt line 125 and Vc line 82 of the right PWB 45 are provided.
52 and a Vc line 154. On the other hand, on the left PWB 46, a diode circuit 54, a booster circuit 72, and a backup circuit 7 provided in the right ECU 14 are provided.
4 are not mounted. In this case, Vba
The potentials of the tt line 152 and the Vc line 154 are always at the ground level.

As shown in FIG. 4, the drain terminal of the ignition circuit 158 is connected to the Vreg line 150 via the resistor 156. The source terminal of the ignition circuit 158 is connected to a positive output terminal 160 (hereinafter, referred to as FL + terminal 160) provided in the left ECU 22. The left ECU 22 includes an FL-terminal 160 and a negative output terminal 162 (hereinafter referred to as an FL-terminal 162). FL + terminal 160 and FL− terminal 162 are connected to both ends of squib 40, respectively.

The safing sensor 164 is connected to the FL-terminal 162. The safing sensor 164 is a sefing sensor 9 provided in the right ECU 14.
Similar to 2, it is a mechanical acceleration sensor. The safing sensor 164 is turned on when an acceleration having a component exceeding a predetermined value acts on the left ECU 22 in a predetermined direction.

The safety circuit 166 is connected to the safing sensor 164. The safety circuit 166 is configured by an FET element as in the case of the right ECU 14. The source terminal of the safety circuit 166 is connected to the GND line 168. The left ECU 22 includes an E3I terminal 170 connected to the GND line 168. The E3I terminal 170 is connected to the E3O terminal 140 of the right ECU 14. That is, the E3I terminal 170
Is grounded via the right ECU 14.

The left ECU 22 has a CPU 172. CPU 172 is supplied with power from Vreg line 150. One end of a communication line 174 is connected to the CPU 172. The other end of the communication line 174
It is connected to SI terminal 176. DSI terminal 176
Is connected to the DSO terminal 124 of the right ECU 14. When detecting any abnormality, the CPU 172 outputs a signal indicating the state of the abnormality to the communication line 174. The signal output to the communication line 174 is
It is transmitted to the CU. The right ECU 14 is the left ECU
When receiving the abnormal signal issued from 22, the contents thereof are stored in the EEPROM 102, and processing such as turning on the warning lamp 30 is performed.

The gate terminal of the safety circuit 166 is connected to the CPU 172. Further, an acceleration sensor 178 for detecting acceleration generated in the vehicle when energy is input to the vehicle from the left side is connected to the CPU 172. CPU 172 turns on safety circuit 166 when it is determined based on the output signal of acceleration sensor 178 that energy exceeding a predetermined value has been input from the left side of the vehicle.

The left ECU 22 includes an ignition control circuit 182,
A 5V power supply circuit 186 and a latch circuit 188 are provided. These circuits function similarly to the ignition control circuit 108, the 5V power supply circuit 116, and the latch circuit 114 included in the right ECU 14, respectively.

The left ECU 22 has a half-fit detection circuit 190. The L1 terminal 192 of the left ECU 22 is connected to the half-fit detection circuit 190. Left E
The CU 22 also has an L2 terminal 196 connected to the Vreg line 150 via a resistor 194. L2
The terminal 196 is connected to the L1 terminal 192 by properly fitting a connector (not shown).

When the L1 terminal 192 and the L2 terminal 196 are properly fitted, the power supply voltage Vreg is guided to the half-fitted detection circuit 190. In other words, the half-fit detection circuit 1
If the power supply voltage Vreg is not guided to 90, it can be determined that the connector is not properly fitted.

The half-fitting detection circuit 190 has an L1 terminal 192
When the power supply voltage Vreg is not supplied from the CPU, it is determined that the connector is not properly fitted, and an abnormal signal is output to the CPU 172. When an abnormal signal is supplied from the half-fit detection circuit 190, the CPU 172 outputs a signal indicating the abnormal state to the communication line 174.

Hereinafter, an operation when energy exceeding a predetermined value is input from the right side of the vehicle to the vehicle equipped with the system of this embodiment will be described. When the above-described energy acts on the vehicle equipped with the system of the present embodiment, the right ECU 1
4 is turned on, and the acceleration sensor 1 built in the right ECU 14 is turned on.
With 04, the acceleration according to the energy is detected. When the acceleration sensor 104 detects the acceleration, the CPU 100 of the right ECU 14 turns on both the ignition circuit 86 and the safety circuit 94.

As described above, when all of the safing sensor 92, the ignition circuit 86, and the safety circuit 94 are turned on, the power supply voltage Vreg is applied to the squib 34 incorporated in the right side airbag module 32. When the power supply voltage Vreg is applied to the squib 34, the inflator built in the right side airbag module 32 is ignited, and the opening of the right side airbag is started.

When energy is applied from the right side of the vehicle, the battery 10 is damaged, or the battery 10
If the wire harness that connects the right ECU 14 and the right ECU 14 is damaged and power cannot be supplied from the battery 10 to the right ECU 14, the system of the present embodiment operates as follows.

In a situation where power can be supplied from the battery 10 to the right ECU 14, the voltage Vreg boosted by the booster circuit 72 is supplied to the backup circuit 74. While the voltage Vreg is supplied to the backup circuit 74, the backup capacitor 78 is charged with electric charge until the potential difference between both ends reaches the voltage Vreg. When the backup capacitor 78 is fully charged and the battery 1
When the power supply from 0 is stopped and all of the ignition circuit 86, the safing sensor 92, and the safety circuit 94 are turned on, the electric charge charged in the backup capacitor 78 is discharged through the diode 80. It is supplied to the squib 34.

The backup capacitor 78 is provided with a capacity capable of sufficiently storing an electric charge necessary for igniting the inflator. For this reason, according to the system of the present embodiment, the right side airbag can be reliably expanded even in a situation where power cannot be supplied from the battery 10 to the right ECU 14.

Next, the operation when energy exceeding a predetermined value is input from the left side of the vehicle to the vehicle equipped with the system of this embodiment will be described. When the above-described energy acts on the vehicle equipped with the system of this embodiment, the left ECU 2
2 is turned on, and the acceleration sensor 178 included in the left ECU 22 detects an acceleration corresponding to the energy. When the acceleration sensor 178 detects such acceleration, the CPU 172 of the left ECU 22 turns on both the ignition circuit 158 and the safety circuit 166.

The Vreg line 150 of the left ECU 22 is
It is substantially connected to the battery 10 via the power supply connection line 24. For this reason, the safing sensor 164,
When the ignition circuit 158 and the safety circuit 166 are all turned on, the power supply voltage Vreg is applied to the squib 40 built in the left side airbag module 36. When the power supply voltage Vreg is applied to the squib 40, the inflator built in the left side airbag module 36 is ignited, and the opening of the left side airbag is started.

When energy is applied from the left side of the vehicle, the battery 10 is damaged, or the battery 10
If the wire harness connecting the ECU and the right ECU 14 is damaged and power cannot be supplied from the battery 10 to the right ECU 14, the system of the present embodiment operates as follows.

As described above, while power is being supplied from the battery 10 to the right ECU 14, the backup capacitor 78 incorporated in the right ECU 14
It is fully charged. When the ignition circuit 158, the safing sensor 164, and the safety circuit 166 of the left ECU 22 are turned on in a state where the backup capacitor 78 is sufficiently charged, the electric charge charged in the backup capacitor 78 is transferred to the power supply connection line. 24, reach the Vreg line 150 of the left ECU 22,
Further, it is discharged through the squib 40. As a result, the inflator built in the left side airbag module 36 is ignited, and the left side airbag is expanded.

As described above, according to the system of this embodiment, although the backup power supply (the booster circuit 72 and the backup circuit 74) is mounted only in the right ECU 14, energy is input from the right side of the vehicle. And when energy is input from the left side of the vehicle, the left and right side airbags can be appropriately opened.

If the backup power supply is provided in only one of the right ECU 14 and the left ECU 22 as in the present embodiment, the number of parts, the cost, and the weight of the system can be reduced. In the present embodiment, the right PWB 45 and the left PWB 46 are shared. The system according to the present embodiment further reduces costs in this regard.

In the present embodiment, each time the IG switch 16 is turned on and at a predetermined time, the right ECU 14 and the left ECU 22 check whether the system can function normally. In the system of the present embodiment, whether the backup capacitor 78 has failed, whether the output voltage Vbatt of the battery 10 is an appropriate value, whether short-circuit or open-circuit has occurred between both ends of the squibs 34, 40, Vreg Lines 64 and 150 and GND lines 95,
Items such as whether a short circuit or open circuit has occurred in 168 are inspected.

These inspections are performed by operating the components of the right ECU 14 and the components of the left ECU 22 according to a predetermined inspection pattern, and monitoring whether or not an appropriate phenomenon appears with the operations. realizable. By the way, in the present embodiment, the backup capacitor 78 is mounted only on the right ECU 14. The output voltage Vbatt of the battery 10 is supplied only to the right ECU 14. Therefore, if the same inspection is performed by the left ECU 22 and the right ECU 14, the left EC 22
In U22, abnormality of the backup capacitor 78,
In addition, a situation in which the output voltage Vbatt abnormality of the battery 10 is erroneously determined may occur.

The above-described erroneous determination of the abnormality is performed, for example, by using the right side E
It is also possible to prevent the problem by making the inspection program stored in the CPU 100 of the CU 14 and the inspection program stored in the CPU 172 of the left ECU 22 different programs. However, according to this method, the CPU 100 for the right ECU 14 and the left ECU 22
And the CPU 172 cannot be shared.

FIG. 6 shows a state in which an erroneous determination of an abnormal state is prevented.
4 shows a flowchart of an example of a control routine executed by the CPU 100 and the CPU 172 in the present embodiment so that the CPU 100 and the CPU 172 can be shared. The routine shown in FIG. 6 is started by both the right ECU 14 and the left ECU 22 when the IG switch 16 is turned on (including the state in which the switch 52 is turned on). When the routine shown in FIG. 6 is started, first, the process of step 200 is executed.

At step 200, the CPU 100 or 172 is initialized. Specifically, the CPU 10
Processing such as setting of input / output ports provided in 0, 172 and resetting of various flags are executed. When the process of step 200 ends, the process of step 202 is executed next.

At step 202, the battery voltage Vbatt
Is "0". This step 202
In the right ECU 14, the CPU 100 determines whether or not the potential of the Vbatt line 125 is "0". On the other hand, in the left ECU 22, the CPU 172 determines whether or not the potential of the Vbatt line 152 is "0".

After the IG switch 16 is turned on, the potential of the Vbatt line 125 of the right ECU 14 is immediately boosted to the vicinity of the power supply voltage Vreg. Therefore, the right ECU 14
In, the condition of step 202 is not satisfied. On the other hand, the potential of the Vbatt line 152 of the left ECU 22 is maintained at the ground level in any case. Therefore, the condition of step 202 is satisfied in the left ECU 22. In other words, if the condition of step 202 is not satisfied, the CPU mounted on the ECU is replaced by the CPU mounted on the right ECU 14.
If it is 100, and if the condition of step 202 is satisfied, it can be recognized that the CPU is the CPU 172 mounted on the left ECU 22.

If it is determined in step 202 that Vbatt = 0 is not established, that is, if the CPU
If it is recognized that it is mounted on the CU 14, the process of step 204 is executed next. In step 204, it is checked whether the backup capacitor 78 is normal. In the right ECU 14, when the IG switch 16 is turned on, the supply of the voltage Vreg to the backup circuit 74 starts. When the voltage Vreg starts to be supplied to the backup circuit 74, the backup capacitor 78 starts to be charged with a charge according to a time constant determined by the resistance value R of the resistor 76 and the capacitance C of the backup capacitor 78.

In step 204, it is determined whether or not the charging voltage Vc of the backup capacitor 78, that is, the potential Vc of the Vc line 82 is boosted at an appropriate speed. As a result, when the potential rising speed of the Vc line 82 is appropriate for the time constant RC, it is determined that the backup capacitor 78 is normal. on the other hand,
If the potential rising speed of the Vc line 82 is not appropriate for the time constant RC, it is determined that the backup capacitor 78 is abnormal. If it is determined that an abnormality has occurred in the backup capacitor 78, the abnormality is stored in the EEPROM 102 and the warning lamp 30 is turned on. When the process of step 204 is completed, the process of step 206 is executed.

If it is determined in step 202 that Vbatt = 0 is established, that is, if the CPU
If it is recognized that the device is mounted on the device 22, step 204 is jumped, and the process of step 206 is executed immediately after step 202. Left ECU2
2, no backup capacitor is mounted.
Therefore, when the processing of step 204 is performed by the left ECU 22, the CPU 172 always determines that an abnormality has occurred in the backup capacitor. According to the present embodiment, the processing of step 204 is not executed by the left ECU 22. For this reason, it is possible to avoid a problem that the left ECU 22 erroneously determines that the backup capacitor is abnormal.

In step 206, other initial inspections are performed except for the initial inspection of the backup capacitor 78. Specifically, in step 206, squib 3
Inspection is performed on components that the right ECU 14 and the left ECU 22 have in common, such as a short circuit or an open circuit near 4,40. If any abnormality is detected in step 206, the abnormality is stored in the EEPROM 102 and the warning lamp 30 is turned on. When the process of step 206 ends, the process of step 208 is executed next.

In step 208, a test for a constant test item except a test for the power supply voltage Vbatt is performed. Specifically, an inspection related to a short circuit / open of the ignition system, a short circuit / open of the acceleration sensors 104 and 178, and the like are executed. If any abnormality is detected in step 208,
The abnormality is stored in the EEPROM 102 and the warning lamp 30 is turned on. When the process of step 208 is completed, the process of step 210 is executed next.

At step 210, the battery voltage Vbatt
Is "0". As a result, Vbatt
If it is determined that = 0 holds, the process of step 208 is executed again. On the other hand, when it is determined that Vbatt = 0 is not established, the process of step 212 is executed next. As in the case of step 202 described above, the condition of step 210 is determined to be satisfied by the left ECU 22 and is determined not to be satisfied by the right ECU 14. Therefore, the left ECU 22 repeatedly executes the processing of steps 208 and 210 until the IG switch 16 is turned off. On the other hand, the right ECU 14 always executes step 212 following step 210.

At step 212, a check is made for a decrease in the power supply voltage Vbatt. In this step 212,
The potential of the Vbatt line 125 is the output voltage V of the battery 10.
It is determined whether or not the value is appropriate as batt. As a result, if the potential of the Vbatt line 125 is an appropriate value, it is determined that the battery voltage Vbatt is normal. On the other hand, Vba
If the potential of the tt line 125 is unduly lowered, it is determined that the battery voltage Vbatt is abnormal. When it is determined that the battery voltage Vbatt is abnormal,
The warning lamp 30 is turned on. When the processing in step 212 ends, the processing in step 208 is executed again. Thereafter, the right ECU 14 repeats step 208 until the IG switch 16 is turned off.
To 212 are executed.

The potential of the Vbatt line 125 of the left ECU 22 is always at the low level. Accordingly, when the processing of step 212 is executed by the left ECU 22, the CPU 17
2 always determines that the battery voltage Vbatt is abnormal. According to the present embodiment, the processing of step 212 is not executed by the left ECU 22. For this reason, the left ECU 22
Thus, it is possible to avoid erroneous determination of the abnormality of the battery voltage Vbatt.

By the way, in the above embodiment, Vba
The CPU 100, 172 selects an inspection item based on whether or not the potentials of the tt lines 125, 152 are “0”, but the basis of selection of inspection items is limited to the potentials of the Vbatt lines 125, 152. Not something. For example, a pull-up resistor or a pull-down resistor is mounted at different positions on the right ECU 14 and the left ECU 22,
U100 and 172 may be made to select an inspection item based on the difference. In addition, data indicating the right ECU 14 is stored in the EEPROM 102 mounted on the right ECU 14 in advance, and the CPU 100, 172 determines whether the data can be read.
May select an inspection item.

In the above embodiment, the right ECU
14 is a right-side controller according to claim 1;
U22 corresponds to the "left control device" of the first embodiment, the booster circuit 72 and the backup circuit 74 correspond to the "backup power supply" of the first embodiment, and the Vreg line 64 corresponds to the "left control device" of the first embodiment. Power system ”and Vreg
The line 150 corresponds to the “power supply system of the left control device” according to claim 1.

[0095]

As described above, according to the present invention, the backup power supply provided in one of the right control device and the left control device can be shared by both the right control device and the left control device. Therefore, according to the present invention, it is possible to realize a side bag control device capable of reliably operating the left and right side air bags without providing a plurality of backup power supplies.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a side airbag system according to an embodiment of the present invention.

FIG. 2 is a block diagram showing an electrical configuration of the side airbag system shown in FIG.

FIG. 3 is a circuit diagram of a right ECU shown in FIG. 2;

FIG. 4 is a circuit diagram of a left ECU shown in FIG. 2;

FIG. 5 shows a part of a right PWB used for a right ECU and a corresponding part of a left PWB used for a left ECU.

FIG. 6 shows a CPU of a right ECU and a CPU of a left ECU.
3 is a flowchart of an example of a control routine executed in step S1.

[Explanation of symbols]

 Reference Signs List 10 Battery 14 Right ECU (right control device) 16 IG switch 22 Left ECU (left control device) 24 Power supply connection line 32 Right side airbag module 34, 40 Squib 36 Left side airbag module 72 Boost circuit 74 Backup circuit 78 Backup capacitor 100,172 CPU

Claims (1)

[Claims] 1. A right control device for controlling operation of a right side airbag disposed on a right side of a vehicle, and a left control device for controlling operation of a left side airbag disposed on a left side of the vehicle. In the side airbag control device provided, one of the right control device and the left control device includes a backup power supply, and a power supply system of the right control device and a power supply system of the left control device are connected to a power supply line. A side airbag control device, wherein the side airbag control device is connected via an airbag.