JPH0592005U - Vehicle occupant protection device - Google Patents

Abstract

(57) [Summary] [Purpose] To notify the failure of the diagnostic circuit that checks the abnormality of the collision detector or the operation control circuit. [Structure] A reset circuit which inputs a pulse of a constant cycle from a diagnostic circuit and supplies a reset signal to the diagnostic circuit when the input state of the pulse is abnormal, and the reset signal from the reset circuit is counted to reach a predetermined value. In addition, a notifying means for notifying a failure of the diagnostic circuit is provided.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a vehicle occupant protection device that protects data in a non-volatile memory when a CPU runs out of control.

[0002]

[Prior Art]

 2. Description of the Related Art As a conventional vehicle occupant protection device, for example, there is one as shown in FIG. In FIG. 2, 1 is an on-vehicle battery, 2 is an ignition switch connected to the on-vehicle battery 1, 3 is a controller, 4 is a DC power source for deploying an air bag, and the on-vehicle battery 1 is connected via the ignition switch 2. The battery voltage supplied to the controller 3 is boosted by the DC / DC converter 5 for boosting high voltage, and the backup capacitor 7 is charged via the resistor 6.

In this case, the backflow prevention diodes 8a to 8c prevent the backflow, and the diode 9 prevents the current from flowing into the backup capacitor 7. Reference numeral 10 is a diagnostic circuit including a CPU 10a and the like, and 11 is a diagnostic circuit power supply unit, which is supplied with a battery voltage from the vehicle-mounted battery 1 and supplies a predetermined voltage to the diagnostic circuit 10. Reference numeral 12 is a non-volatile storage unit for exchanging data with the diagnostic circuit 10.

Reference numerals 13a to 13e are diodes, and 14 to 19 are collision detection portions provided in various parts of the vehicle body. These are acceleration switches 14a to 19a for closing the input and output at accelerations higher than a predetermined value, and resistors 14b to 19b. It is configured in parallel. The resistors 14b to 19b are not always necessary. Reference numeral 20 denotes a squeeze provided in the steering section or the like, which is an electrode for igniting explosive for deploying an airbag (vehicle occupant protection device) (not shown) provided in the steering section.

Reference numeral 21 is a spiral cable formed of a flexible cord wound around a steering shaft for electrically connecting the squeeze 20 and the controller 3 provided on the vehicle body side. Further, 3a to 3n are output terminals of the above controller, and from this output terminal 3a, a collision detector 14-output terminal 3b-diode 13a-output terminal 3e-spiral cable 21-squeeze 20-output terminal 3f. It is connected to the line L1.

The collision detector 15 is connected between the output terminals 3a, 3c and 3d, and the line L1 and the output terminal 3g are connected, the line L1 and the output terminal 3i are connected, the line L1 and the output terminal 3k are connected, and the line L1 and the output terminal are connected. Diodes 13b to 13e are respectively connected between 3m. Collision detectors 16 to 19 are connected between the output terminals 3g and 3h, between the output terminals 3i and 3j, between the output terminals 3k and 3l, and between the output terminals 3m and 3n, respectively. The output terminals 3h, 3j, 3l, 3n are connected to the line L2. Line L2 is earthed.

Next, the operation will be described. When the ignition switch 2 is closed, the voltage from the in-vehicle battery 1 is boosted by the DC / DC converter 5 and the time constant determined by the resistor 6 and the backup capacitor 7 is charged to the backup capacitor 7 via the diode 8c. The charging voltage of the backup capacitor 7 is always higher than the voltage of the vehicle-mounted battery 1.

The diagnostic circuit 10 inputs data such as the voltage generated in each of the resistors 14b to 19b, the charging voltage of the backup capacitor 7, etc., and any one of the acceleration switches 14a to 19a becomes a state close to a short circuit and the resistors 14b to 19b. When the voltage generated between the terminals of 19b has a value different from that in the normal state, it is determined and stored in the non-volatile storage unit 12. Further, the non-volatile storage unit 12 stores which acceleration switch is turned on when any of the acceleration switches 14a to 19a is turned on due to a collision or the like.

In the above configuration, when the vehicle collides and negative acceleration more than a predetermined value is generated and any one of the acceleration switches 14a and 15a and any one of the acceleration switches 16a to 19a are turned on, the backup capacitor 7 is charged. Voltage flows, for example, as indicated by the broken line, the squeeze 20 generates heat, the explosive is ignited, and the airbag is deployed.

[0010]

[Problems to be solved by the device]

 However, in such a conventional vehicle occupant protection device, a protection means for the memory (nonvolatile storage unit 12) during a runaway of the CPU (diagnosis circuit 10) is not particularly provided. Therefore, there is a problem that the contents of the nonvolatile memory are cleared and rewritten when the CPU runs out of control.

The present invention has been made by paying attention to such a conventional problem, and detects a runaway of the CPU (repeated reset of the CPU) to turn on the power supply of the nonvolatile memory. The purpose is to solve the above problems by blocking or disabling chip select.

[0012]

[Means for Solving the Problems]

 The vehicle occupant protection system according to the present invention counts the reset signal from the reset circuit and notifies the failure of the diagnostic circuit when it reaches a predetermined value.

[0013]

[Action]

 The vehicle occupant protection system according to the present invention can promptly take necessary countermeasures by notifying the failure of the diagnostic circuit, and can accurately perform occupant protection.

[0014]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. Also in this invention, the overall structure of the vehicle occupant protection system is the same as the conventional system shown in FIG.

FIG. 1 shows a diagnostic circuit included in the vehicle occupant protection system of the present invention. In FIG. 1, 101 is a diagnostic circuit for diagnosing an error state of each part of the electronic circuit of the vehicle occupant protection system. CPU, 102 is a counter that counts a reset pulse output from a watchdog timer circuit 103, which will be described later, when the diagnostic CPU 101 is out of control. 103 is a constant frequency from an output port when the program of the CPU 101 is operating normally. This is a watchdog timer circuit that detects a predetermined clock pulse that is output, and repeats and outputs a reset pulse when the clock pulse is not detected when the program operation is abnormal. All of these are well-known. .. Reference numeral 104 is an OR gate, which inputs both the signal output from the diagnostic CPU 101 and the signal from the counter 102, which is the object of the present application. The output terminal of the augment 104 is connected to the collector of a transistor 132 via a resistor 131, and a warning lamp 133 is provided at the base of the transistor 132.

The watchdog timer circuit 103 is composed of resistors 111, 113, 115 and 119, capacitors 112 and 118, inverters 114 and 120, and diodes 116 and 117, as shown in the figure.

The counter 102 is composed of a capacitor 122 and a resistor 121, which are power sources, flip-flops (hereinafter abbreviated as F / F) 123, 124, 125, and an AND gate 126. Since the operation of the above is well known, its detailed description is omitted.

Next, the operation will be described. The diagnostic CPU 101 is constantly diagnosing abnormalities in each part of the electronic circuit. If there is no abnormality in the program operation, a clock of a constant frequency is output from the output pot and given to the watchdog timer circuit 103. The dog timer circuit 103 only outputs L or H and does not output the reset pulse.

On the other hand, during the normal runaway of the CPU 101, the watchdog circuit 102 outputs only one reset pulse, so that the CPU 101 immediately returns and the output of the F / F 125 of the counter 103 becomes high level. There is no warning lamp 133.

On the other hand, when the CPU 101 fails, the watchdog circuit 102 continuously outputs the reset pulse. However, if the CPU 101 does not recover, the reset pulse is also input to the counter 102. Therefore, the negative output from the terminal P of the F / F 124 and the output of the AND gate 126 when the reset pulse becomes high level. Becomes a high level, the Q output of the F / F 125 becomes a high level, the transistor 132 is turned on, the warning lamp 133 is turned on, and the operator is notified of the failure of the CPU 101.

[0021]

[Effect of the device]

 As described above, according to the present invention, the failure of the CPU is distinguished from the case of the runaway, and the warning lamp is lit to notify the failure, so that the necessary countermeasures against the failure of the CPU can be promptly taken. Therefore, there is an effect that occupant protection can be performed accurately.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of the present invention.

FIG. 2 is a circuit diagram of a conventional vehicle occupant protection device.

[Explanation of symbols]

 14-17 Collision detector 20 Operation control circuit 102 Counter 133 Warning lamp (informing means)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hirohisa Nakata, 2-1910, Nisshin-cho, Omiya-shi, Saitama, Kansei Co., Ltd. (72) Shinichiro Tsurushima, 2-1910, Nisshin-cho, Omiya-shi, Saitama, Kansei

Claims (1)

[Scope of utility model registration request] 1. A collision detector mounted on a vehicle, an operation control circuit for inflating an airbag based on a detection output from the collision detector, and at least one of the operation control circuit and the collision detector. A diagnostic circuit that checks one of the abnormalities and outputs a pulse of a constant cycle, a non-volatile storage unit that stores the abnormality detected by the diagnostic circuit, and inputs a pulse of a constant cycle from the diagnostic circuit, In a vehicle occupant protection device including a reset circuit that supplies a reset signal to the diagnostic circuit when the pulse input state is abnormal, when the reset signal from the reset circuit is counted and reaches a predetermined value, the diagnostic circuit An occupant protection device for a vehicle, which is provided with informing means for informing of a failure of the vehicle.