JP4449478B2 - Vehicle safety device - Google Patents

Description

  The present invention relates to a vehicle safety device, and more particularly to a vehicle safety device that prevents a collision with an obstacle in the traveling direction of the vehicle.

  In recent years, as automatic transmissions have become more widespread, there are sudden start and runaway accidents in vehicles caused by mistakes in the accelerator pedal and brake pedal, or by depressing the brake pedal and accelerator pedal at the same time with the intention of depressing only the brake pedal. It has occurred.

  Such an accident is caused by the fact that the vehicle starts only by depressing the accelerator pedal due to the characteristics of the automatic transmission.

  In addition, it is considered that the mistaken depression and simultaneous depression of the accelerator pedal and the brake pedal are usually caused by the driver depressing both the accelerator pedal and the brake pedal with the right foot.

  For example, if the driver intends to depress the brake pedal to stop, but accidentally depresses the accelerator pedal, the braking force is insufficient and the pedal will be depressed more strongly. Will be stepped on.

  In such a case, if the driver thinks that the driver is stepping hard on the brake pedal, the vehicle behavior expected by the driver and the actual vehicle behavior will be severely panicked. Since the accelerator pedal is depressed, the vehicle starts suddenly or goes out of control. This situation is almost the same when the accelerator pedal and the brake pedal are depressed simultaneously.

  As a conventional technique for preventing such sudden start and runaway of the vehicle, the distance between the vehicle and the accelerator pedal is detected, the distance between the vehicles is shorter than the safe distance, and the accelerator pedal is not less than a predetermined value. In such a case, there is a control that reduces the vehicle speed of the host vehicle (see, for example, Patent Document 1).

  Further, in a vehicle stop state or a slow driving state, there has been proposed one that suppresses the throttle valve opening of the engine rather than the accelerator pedal depression amount (see, for example, Patent Document 2).

Furthermore, there is an apparatus that restricts the engine output at the time of start by the obstacle detection signal of the obstacle detection means to prevent sudden start (for example, see Patent Document 3).
JP-A-4-215527 (Summary, Fig. 1) Japanese Patent Laid-Open No. 9-287488 (summary, FIG. 1) JP 2000-255351 (pages 7-8, FIG. 1)

  According to the prior art described in Patent Document 1 above, the clutch or brake device is controlled when the condition that the inter-vehicle distance is shorter than the safe inter-vehicle distance and the depression force of the accelerator pedal is equal to or greater than a predetermined value is satisfied. Therefore, braking is suddenly applied when the condition is satisfied.

  In other words, when the accelerator pedal is strongly depressed (the accelerator pedal force is greater than or equal to a predetermined value) and approaching the preceding vehicle, the brake is suddenly applied when the inter-vehicle distance falls below the safe inter-vehicle distance. The driver may be shocked.

  In addition, when the clutch is disengaged without returning the accelerator, there is a possibility of emptying.

  Furthermore, when using a brake having a negative pressure type booster that uses the intake negative pressure of the engine, the accelerator pedal is strongly depressed at the start of braking. It does not occur and sufficient braking force cannot be obtained.

  In addition, according to the prior art described in Patent Document 2 above, the throttle valve is suppressed every time the vehicle starts or slows down. Therefore, it is dangerous to make a right turn that requires rapid start or rapid acceleration. May be incurred.

  Furthermore, according to the prior art described in Patent Document 3 above, the engine output is uniformly regulated according to the presence or absence of obstacles, so appropriate acceleration power and safety in various situations such as traffic jams and waiting for traffic lights. It is difficult to achieve compatibility of sex.

  Therefore, an object of the present invention is to provide a vehicle safety device capable of appropriately avoiding a collision with an obstacle according to a traveling state or a stopping state of the vehicle.

In order to achieve the above object, a vehicle safety device according to the present invention includes an obstacle distance detection unit that detects an obstacle distance from an own vehicle to an obstacle in the traveling direction, an accelerator pedal depression amount detection unit, Based on the accelerator pedal depression amount, an engine output instruction value is set and stored as a first stored value. When calculating the target output instruction value, when the obstacle distance is less than or equal to the first threshold value, A proportional engine output upper limit value is set and stored as a second stored value, and when the second stored value is smaller than the first stored value , the first stored value is updated to the second stored value , When the second stored value is equal to or greater than the first stored value , the first stored value is maintained as it is , and when the first stored value is smaller than the third stored value that is the previously obtained target output instruction value , the first stored value is maintained . Update 3 stored values to the first stored value When the first stored value is larger than the third stored value, a value obtained by adding a preset value to the third stored value is updated as the third stored value, and the first stored value is a calculation unit for maintaining a third stored value in the case of the third or more stored value updated as it is characterized by comprising an engine control unit for controlling the engine, the by third stored value.

That is, in the present invention, when the first stored value is larger than the third stored value which is the previous target output value, a value obtained by adding a predetermined value to the third stored value is set as the third stored value. When the updated third stored value is equal to or lower than the first stored value, the engine control is performed using the updated third stored value.
As a result, in situations where the first stored value is greater than or equal to the third stored value, it is necessary to increase the engine output. However, in the case where the obstacle distance is less than or equal to the first threshold value, When the third stored value updated by adding a predetermined value is still smaller than the first target value under the situation where the distance is small and it is necessary to suppress the engine output and avoid the obstacle, the third stored value is The engine control is performed, and the obstacle can be surely avoided while achieving the request for the engine output increase.

  Further, a brake control unit is further provided, and when the obstacle distance is equal to or less than a second threshold value lower than the first threshold value, the calculation unit outputs a signal instructing brake operation to the brake control unit. Also good.

  As a result, when the obstacle distance is less than or equal to the second threshold value, the brake is applied in addition to the control of the engine output value, so that collision with the obstacle can be avoided more reliably. Become.

  In this case, the brake may include a negative pressure booster using intake negative pressure of the engine.

  That is, when the brake is activated, the intake negative pressure is generated because the rotational speed of the engine is decreasing, and this negative pressure can be secured as a braking force.

  In addition, a vehicle speed detection unit that detects the vehicle speed of the host vehicle may be further provided, and the calculation unit may calculate the second threshold value based on the vehicle speed.

  As a result, the second threshold value is determined in accordance with the vehicle speed, so that the brake operation is started at a more appropriate time, and the obstacle is more reliably than in the case of using the second threshold value unrelated to the vehicle speed as described above. It is possible to avoid collisions with

  As described above, according to the vehicle safety device of the present invention, it is possible to appropriately avoid a collision with an obstacle according to the traveling state or the stopping state of the vehicle.

Example 1
FIG. 1 shows a configuration of an embodiment of a vehicle safety device according to the present invention. First, as a first embodiment, a vehicle safety device excluding the vehicle speed detection unit 5 and the brake control unit 6 indicated by dotted lines in FIG.

  The vehicle safety device according to the first embodiment includes an obstacle distance detection unit 1, an accelerator pedal depression amount detection unit 2, a calculation unit 3, and an engine control unit 4 which are indicated by solid lines in FIG.

  The obstacle distance detection unit 1 detects the presence or absence of an obstacle in the traveling direction of the host vehicle, and outputs the distance between the obstacle and the host vehicle as an obstacle distance signal, and is generally installed in front of the vehicle. However, it can be added to the rear of the vehicle for reversing.

  The accelerator pedal depression amount detection unit 2 may use a known device that detects the accelerator pedal depression amount by the driver.

  The calculation unit 3 calculates an obstacle using the input unit 31 that reads the obstacle distance signal from the obstacle detection unit 1 and the accelerator pedal depression amount signal from the accelerator pedal depression amount detection unit 2, and the output signal of the input unit 31. CPU32 that performs the determination, RAM33 that the CPU32 uses for calculation, ROM34 that stores the control program and control parameters, and the target engine output instruction value to the engine control unit 4 according to the output data obtained by the CPU32 An output unit 35 and a power source unit 36 for supplying necessary power to these units from the vehicle power source are configured.

  In addition, the engine control unit 4 uses a known device that controls the fuel and intake air amount in accordance with a target engine output instruction value that is an output from the output unit 35 so as to obtain a desired engine output. That's fine.

  FIG. 2 shows the flow of the control program stored in the ROM 34 in the computing unit 3 shown in FIG. 1, and the operation of the first embodiment will be described below with reference to FIG. Note that this flowchart is started at predetermined time intervals, and only the part related to the control by the calculation unit 3 is described, but the initial processing at the time of starting the hardware such as the CPU is omitted.

  The operation of the first embodiment will be described with reference to FIG. Note that steps S100 and S200 indicated by dotted lines in the figure are the operations of Example 2 described later, and thus the description thereof is omitted here.

  First, the CPU 32 reads an obstacle distance signal from the obstacle detector 1 and an accelerator pedal depression amount signal from the accelerator pedal depression amount detector 2 via the input unit 31 (step S1).

  Next, the CPU 32 refers to a table in the ROM 34 in which the relationship between the accelerator pedal depression amount and the engine output instruction value (hereinafter abbreviated as output instruction value) is recorded in advance, thereby reading the accelerator pedal depression amount read in step S1. Based on the signal, an output instruction value is obtained (S2), and this output instruction value is stored in the memory B in the RAM 33 (S3).

  Further, the CPU 32 compares the obstacle distance with a predetermined value as the first threshold value based on the obstacle distance signal read in step S1 (S4).

  In step S4, if it is determined that the obstacle distance is equal to or less than the predetermined value, the engine output is regulated according to the distance to the obstacle, so the ROM 34 in which the relationship between the obstacle distance and the output upper limit value is recorded in advance. By referring to the table, the output upper limit value is obtained based on the obstacle distance signal read in step S1 (S5), and this output upper limit value is stored in the memory C in the RAM 33 (S6).

  Further, the values of the memory B and the memory C are compared (S7), and only when the value of the memory B> the value of the memory C, the smaller value of the memory C is substituted into the memory B (S8).

  After executing the above steps S5 to S8 or when it is determined in step S4 that the obstacle distance> predetermined value, the target engine output instruction obtained in step S17 described later when the flowchart of FIG. The value is assigned to the memory A in the RAM 33 (S9).

  Next, the values of the memory A and the memory B are compared (S10).

  In this case, if the values of memory A and memory B are equal, the process proceeds to step S15 without changing the value of memory A, but if the value of memory A is greater than the value of memory B, the current process calculates Since the output instruction value is smaller than the value calculated in the previous process and the engine output needs to be reduced, the smaller value of the memory B is substituted into the memory A (S11).

  Conversely, if the value of memory A <the value of memory B, the output instruction value calculated in the current process is larger than the value calculated in the previous process and the engine output needs to be increased. The memory A is updated with a value obtained by adding the stored setting value to the memory A (S12).

  Next, the value of the memory A updated in step S12 is compared with the upper limit value MAX of the memory A stored in the ROM 34 in advance (S13), and the upper limit value MAX is stored in the memory A only when the value of the memory A exceeds the upper limit value MAX. (S15).

  Further, the value of memory A updated in step S12 is compared with the value of memory B (same as S14), and only when the value of memory A exceeds the value of memory B, the value of memory B is assigned to memory A (same as S16). ).

  Note that in the processing of steps S13 and S15 described above, the value of the memory A is limited to be equal to or lower than the upper limit value MAX. This is in order to avoid overflow during calculation in consideration of actual programming. It is processing.

  Further, in the processing of the above steps S14 and S16, the value of the memory A is limited to be equal to or less than the value of the memory B. This is because the value of the memory A calculated in the above step S10 is the step This is to prevent exceeding the value stored in the memory B in S3 or S8.

  Next, the value of the memory A currently obtained is substituted into the target engine output instruction value (S17), and this value is output to the engine control unit 4 via the output unit 35 (S18). finish.

Example 2
In the second embodiment of the present invention, the obstacle distance detection unit 1, the accelerator pedal depression amount detection unit 2, the calculation unit 3, and the engine control unit 4 shown by the solid line in FIG. A vehicle safety device to which a vehicle speed detection unit 5 and a brake control unit 6 indicated by dotted lines are added will be described. The vehicle speed detection unit 5 added in the second embodiment may use a known device that detects the vehicle speed of the host vehicle, and the brake control unit 6 may use a known device.

  First, the operation of the second embodiment will be described with reference to FIG. As in the case of the first embodiment, this flowchart is started at predetermined time intervals, and only the part related to the control by the arithmetic unit 3 is described. Is omitted.

  The basic operation of the second embodiment is the same as that of the first embodiment described above, but is different from the first embodiment in that steps S100 and S200 indicated by dotted lines in the figure are added.

  In Example 2, in addition to the obstacle distance signal from the obstacle detection unit 1 and the accelerator pedal depression amount signal from the accelerator pedal depression amount detection unit 2 in step S1 of FIG. Read the signal.

  In step S100 performed after step S1, a safe obstacle distance is calculated based on the vehicle speed signal read in step S1.

Thereafter, the steps S2～S1 8 was carried out as in Example 1 above, in step S200, the following processing is performed.

  First, the obstacle distance is compared with the safe obstacle distance that is the second threshold based on the obstacle distance signal read in step S1 (step S201). If it is determined that the obstacle distance is greater than the safety obstacle distance, the brake is deactivated by outputting a control signal to the brake control unit 6 via the output unit 35 (S203), and the obstacle distance ≦ If it is determined that the distance is a safe obstacle distance, the brake is activated (S202).

  In the configuration of the vehicle safety device shown in FIG. 1, the engine control unit 4 is a component of the vehicle safety device, but a configuration in which a part of the vehicle safety device is included in the engine control unit 4 may be used.

It is the block diagram which showed the Example of the vehicle safety device which concerns on this invention. FIG. 2 is a flowchart showing a control program used in the embodiment of the vehicle safety device according to the present invention shown in FIG.

Explanation of symbols

1 Obstacle distance detector
2 Accelerator pedal depression detection unit
3 Calculation unit
4 Engine control unit
5 Vehicle speed detector
6 Brake control part In the figure, the same reference numerals indicate the same or corresponding parts.

Claims (4)

An obstacle distance detection unit for detecting an obstacle distance from the own vehicle to the obstacle in the traveling direction;
An accelerator pedal depression amount detection unit;
An engine output instruction value is set based on the current accelerator pedal depression amount, stored as a first stored value , and when the obstacle distance is less than or equal to the first threshold value when calculating the target output instruction value, the obstacle set the output upper limit value of the proportional engine distance stores as a second stored value, when the second storage value is less than the first stored value, and updates the first stored value in the second memory value On the other hand, when the second stored value is equal to or greater than the first stored value , the first stored value is maintained as it is , and when the first stored value is smaller than the third stored value that is the previously obtained target output instruction value. The third stored value is updated to the first stored value, and when the first stored value is greater than the third stored value, a value obtained by adding a preset set value to the third stored value is set to the third stored value. Update as stored value, the first stored value is greater than or equal to the updated third stored value In this case, the arithmetic unit that maintains the third stored value as it is;
An engine control unit that performs engine control according to the third stored value ;
Vehicle safety apparatus comprising the. In claim 1,
A brake control unit is further provided, and when the obstacle distance is equal to or less than a second threshold value lower than the first threshold value, the calculation unit outputs a signal instructing brake operation to the brake control unit. Vehicle safety device. In claim 2,
A vehicle safety device characterized in that the brake has a negative pressure type booster using intake negative pressure of the engine. In claim 2 or 3,
A vehicle safety device further comprising a vehicle speed detection unit that detects a vehicle speed of the host vehicle, wherein the calculation unit calculates the second threshold value based on the vehicle speed.

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