JP4158177B2 - Inter-vehicle distance control device - Google Patents

Description

  The present invention relates to an inter-vehicle distance control device that performs constant deceleration control based on a distance to a preceding vehicle, a host vehicle speed, and a relative distance to the preceding vehicle, and provides an appropriate inter-vehicle distance between the preceding vehicle.

As a conventional inter-vehicle distance control device, there is an automobile collision warning device (see, for example, Patent Document 1).
FIG. 5 is a block diagram showing a schematic configuration of a conventional apparatus.
In FIG. 5, the inter-vehicle distance sensor 1 uses, for example, a known scanning laser radar device.
The vehicle speed sensor 2 detects the speed of the host vehicle. The driving state detection sensor 3 which is another sensor outputs a driving state signal for making the set safe inter-vehicle distance variable according to the driving state.

The driving state detection sensor 3 includes a gear position detection sensor, a wiper movable detection sensor, a lane change light detection sensor, and the like.
The control means 4 generates a brake operation signal based on the input signals from the sensors 1 to 3 and outputs it to the brake means 5 and outputs an alarm signal to the alarm means 6.

  The control means 4 detects the relative speed calculated by the relative speed calculating section 4a and the relative speed calculated by the relative speed calculating section 4a and the vehicle speed sensor 2 based on the inter-vehicle distance information input from the inter-vehicle distance sensor 1. A safe inter-vehicle distance calculation unit 4b that calculates a safe inter-vehicle distance based on the vehicle speed and the driving state signal detected by the driving state detection sensor 3, and the inter-vehicle distance information and the safe inter-vehicle distance calculation input from the inter-vehicle distance sensor 1. A comparison unit 4c that compares the safe inter-vehicle distance calculated by the unit 4b and outputs a brake operation signal for brake operation to the braking unit 5 and outputs an alarm signal to the alarm unit 6 based on the comparison result It has.

Next, the operation of the conventional apparatus will be described.
The relative speed calculation unit 4a calculates the relative speed with the preceding vehicle based on the inter-vehicle distance information from the inter-vehicle distance sensor 1. Further, the safe inter-vehicle distance calculation unit 4b is based on a relative speed calculated by the relative speed calculation unit 4a, a host vehicle speed detected by the vehicle speed sensor 2, and a gear position sensor (driving state detection sensor) indicating a speed change of the host vehicle. The safe inter-vehicle distance is calculated based on the gear position signal.

  Next, the inter-vehicle distance information input from the inter-vehicle distance sensor 1 and the safe inter-vehicle distance calculated by the safe inter-vehicle distance calculation unit 4b are compared by the comparison unit 4c. If the former is determined to be smaller than the latter, the alarm means 6 is moved to alert the driver that the inter-vehicle distance is shorter than the safe inter-vehicle distance by the buzzer. In addition, a brake operation signal is output to the braking means to automatically perform the brake operation so as to increase the inter-vehicle distance.

JP-A-9-142237

  As described above, the conventional device increases the inter-vehicle distance by automatic operation of the braking means when the inter-vehicle distance is shorter than the safe inter-vehicle distance. For example, when the inter-vehicle distance decreases to overtake the preceding vehicle, etc. There is no need to operate the brakes, and the braking operation at this time may be uncomfortable for the driver. Also, when trying to increase the inter-vehicle distance by simply operating the brakes, the driver may However, there was a problem of giving a sense of incongruity due to sudden changes in driving.

  The present invention has been made to solve the above-described problems, and can smoothly increase the inter-vehicle distance under a constant deceleration without deteriorating the driving feeling, and can also reduce the traveling speed from normal traveling. An object of the present invention is to obtain an inter-vehicle distance control device that does not give the driver a sense of incongruity even if it is replaced.

An inter-vehicle distance control device according to the present invention includes an inter-vehicle distance detection unit that detects an inter-vehicle distance from a preceding vehicle, a vehicle speed detection unit that detects an own vehicle speed, and a relative speed calculation unit that calculates a relative speed based on the inter-vehicle distance. Target deceleration setting means for setting a target deceleration based on relative speed, host vehicle speed, and inter-vehicle distance, constant deceleration control means for performing constant deceleration control of the vehicle according to the set target deceleration, and constant deceleration Informing the driver during speed control , the constant deceleration control means provides a distance hysteresis with respect to the safe inter-vehicle distance from the preceding vehicle, and the safe inter-vehicle distance between the vehicle and the preceding vehicle When tracking is running and constant deceleration control is not performed, constant deceleration control is not performed until the inter-vehicle distance from the preceding vehicle reaches a predetermined value, and when constant deceleration control is performed, The distance from the preceding vehicle is And it performs constant deceleration control until the value.

  According to the present invention, it is possible to prevent a rear-end collision due to insufficient distance between the vehicles with a high probability, and the driver does not feel uncomfortable even when switching from normal traveling to decelerating traveling.

Embodiment 1 FIG.
Next, Embodiment 1 of the present invention will be described with reference to the drawings. 1 is a block diagram showing an inter-vehicle distance control apparatus according to Embodiment 1 of the present invention. In the figure, the same reference numerals as those in FIG. 5 denote the same or corresponding parts.
In FIG. 1, the control means 4A according to Embodiment 1 of the present invention includes a relative speed calculation means 4A1 for calculating a relative speed from the inter-vehicle distance information from the inter-vehicle distance detection means (inter-vehicle distance sensor) 1, and the calculated relative A target deceleration setting unit 4A2 that reads and sets a target deceleration from a map set in advance from the vehicle speed detected by the speed, inter-vehicle distance information and the vehicle speed detection means 2, and is detected by the set target deceleration and vehicle speed detection means 2. And a constant deceleration control unit 4A3 for outputting a constant deceleration signal determined from the generated vehicle speed to the braking means 5.

The notification means 6A notifies the driver that the constant deceleration control is being performed.
When the driver operation detection unit 4B detects a manual brake operation by the driver, the driver operation detection unit 4B cancels the constant deceleration control by the constant deceleration control unit 4A3 and executes the brake operation by the driver. The constant deceleration control unit 4A3 and the driver operation detection unit 4B constitute constant deceleration control release means.

The driver operation detection unit 4B detects a winker operation performed when overtaking the preceding vehicle, a steering wheel operation when changing lanes accompanying overtaking the preceding vehicle, or an accelerator operation during acceleration, in addition to manual brake operation by the driver, and performs constant deceleration control. Is to be canceled.
When the constant deceleration control is released, the constant deceleration control unit 4A3 gradually decelerates the target deceleration when the target deceleration is 0.2G or higher and releases the control when the target deceleration is 0.2G or lower. To do.

FIG. 2 is a system configuration diagram showing the inter-vehicle distance control apparatus according to Embodiment 1 of the present invention, and shows a case where it is applied to a master cylinder using a booster valve in ABS (Anti-Skid Braking System). . Note that the operation of the ABS H / U is not directly related to the present invention, so only the minimum necessary explanation will be given.
In FIG. 2, the ECU constitutes the control means 4A in FIG. 1, and inputs its own vehicle speed from the vehicle speed detection means 2 (wheel speed sensor for detecting the wheel speed of each wheel). As an example of the brake control means 5, a booster valve BV that alternately introduces and controls atmospheric pressure and negative pressure to the diaphragm constituting the master bag M / B is taken as an example.

Next, the operation of the master bag M / B operated by the booster valve BV will be described.
Normally, the master bag M / B depresses the brake pedal BP and pushes back a piston (not shown) in the master bag M / B against the spring pressure through the diaphragm, and sends the brake oil in the sump T to the master cylinder M / C. Pressure is generated.

  According to FIG. 2, normally, when the solenoid of the booster valve BV is de-energized, the atmosphere introduction side is opened and the negative pressure introduction side is closed, so that one side of the diaphragm is large through the first introduction port (1). Atmospheric pressure is applied, and a negative pressure is normally applied to the other side of the diaphragm through the third inlet (3), so that a large pressure difference is generated in the diaphragm. Therefore, a pressure several times as large as the driver's depressing force on the brake pedal BP is generated in the diaphragm. As a result, the piston (not shown) of the master bag M / B is pushed back against the spring pressure, and the brake oil in the sump T is sent to the master cylinder M / C to generate the brake pressure.

However, by adding the booster valve BV to the master bag M / B, the braking force can be generated without stepping on the brake pedal BP.
In other words, the booster valve control signal is output from the ECU to the booster valve BV to control the solenoid, the first inlet (1) is air, the second inlet (2) is shut off, and the third inlet (3) is negative. By introducing the pressure, the piston in the master bag M / B is moved to the left in the figure, the piston is pushed back against the spring pressure, and the brake oil in the sump T is sent to the master cylinder M / C to generate the brake pressure. To start deceleration operation.

  Further, when the brake is released, the master bag is established by blocking the first introduction port (1) by controlling the boost valve BV by the boost valve control signal and introducing negative pressure to the second introduction port (2) and the third introduction port (3). The piston is pushed back by the spring in M / B, and the brake oil is shut off from the oil supply from T to the master cylinder M / C, so that the brake is released.

Hereinafter, the deceleration operation will be described with reference to the deceleration characteristic diagram shown in FIG.
First, before describing the operation, a method for calculating the relative speed will be described. The relative speed is obtained periodically from the change in the inter-vehicle distance detected by the inter-vehicle distance detection means 1 and the change in the own vehicle speed detected by the vehicle speed detection means 2.

  For example, if the inter-vehicle distance input every 100 ms during driving at a vehicle speed of 100 km / h changes to 100 m and 98 m, the relative speed is (100 m−98 m) /0.1 [s] = 20 ms = 72 [km / h]. It becomes.

  The target deceleration setting in the target deceleration setting unit 4A2 is performed by setting a relative speed 0 having threshold values of target decelerations 0.1G, 0.2G, and 0.3G as shown in FIGS. 4 (a) and 4 (b). A map for every 60 km / h is prepared. When the inter-vehicle distance becomes short, the target deceleration is set by reading the relative speed, the host vehicle speed, and the inter-vehicle distance from a map stored in a storage means (not shown).

It is also possible to suddenly start the target deceleration from 0.3 G by interruption, a curve or the like. Furthermore, even if the constant deceleration control is started, the target deceleration can be changed from 0.1 G to 0.2 G when the inter-vehicle distance gradually decreases. The reverse is also possible.
As the relative speed increases, the relationship between the inter-vehicle distance at which the 0.1G threshold and the 0.3G threshold cross each other and the host vehicle speed are more frequently generated. Although it is possible to set a target deceleration of 0.3G or more, a deceleration of 0.3G or more becomes a sudden brake mode, which causes a problem of passenger safety.

  Next, a description will be given based on the constant deceleration control unit 4A that performs control to the target deceleration with reference to the functional block diagram of FIG. The target deceleration set in the target deceleration setting unit 4A2 by the vehicle body deceleration calculated from the change per unit time of the vehicle speed input from the vehicle speed detection means 2 in the vehicle body deceleration calculation unit 45 and the map according to the characteristic diagram of FIG. Find the deviation from. This deviation amount is differentiated and integrated by a differentiation element and an integration element, the respective processing results are added, and a hydraulic pressure (brake hydraulic pressure) command value proportional to the added value is input to the control amount conversion unit 43.

  The control amount converter 4B determines the duty ratio of the pulse train signal that determines the booster valve opening time based on the hydraulic pressure command value, and then transmits the duty ratio to the output unit 44. The output unit 44 inputs the pulse train signal having the transmitted duty ratio to the excitation solenoid of the booster valve BV. As a result, the booster valve BV adjusts the atmospheric pressure sent to the diaphragm D, gradually moves the piston in the master back MB to the left side, and gradually sends T brake oil to the master cylinder M / C for deceleration. .

  The output unit 44 also has a function of outputting the output of the wheel speed sensor to the vehicle body deceleration calculating unit 45. Further, an acceleration sensor (G sensor) may be provided instead of the vehicle body deceleration calculation unit 45, and the sensor output may be compared with the set target deceleration.

The operation of the ABS H / U is irrelevant in the present invention, but in some systems, the actuator can be braked even if the driver does not step on the brake pedal by an actuator due to deformation of the H / U. It goes without saying that such an actuator can be applied to the inter-vehicle distance control apparatus according to Embodiment 1 of the present invention.
In the constant deceleration control, it is desirable to provide distance hysteresis with respect to the safe inter-vehicle distance .
For example, when a constant deceleration control is not performed during tracking while providing a safe inter-vehicle distance between the host vehicle and the preceding vehicle, the constant deceleration control is not performed until the inter-vehicle distance reaches D1. Conversely, when constant deceleration control is being performed, constant deceleration control is performed until D0 (<D1).

According to the present invention, an inter-vehicle distance detection unit that detects an inter-vehicle distance from a preceding vehicle, a vehicle speed detection unit that detects an own vehicle speed, a relative speed calculation unit that calculates a relative speed based on the inter-vehicle distance, Target deceleration setting means for setting a target deceleration based on speed, host vehicle speed, and inter-vehicle distance; constant deceleration control means for performing constant deceleration control of the vehicle according to the set target deceleration; and constant deceleration control Informing the driver of the inside , the constant deceleration control means provides a distance hysteresis with respect to the safe inter-vehicle distance from the preceding vehicle, and provides a safe inter-vehicle distance between the vehicle and the preceding vehicle. During tracking driving, when constant deceleration control is not performed, constant deceleration control is not performed until the distance between the vehicle and the preceding vehicle reaches a predetermined value, and when constant deceleration control is performed, the preceding vehicle The distance between the vehicle and the Since in performing constant deceleration control, it is possible to prevent rear-end collision caused by the inter-vehicle distance insufficient probability high, there is an effect that even in place of the deceleration from the normal running never Motas the driver a sense of discomfort.

It is a block diagram which shows the inter-vehicle distance control apparatus which concerns on Embodiment 1 of this invention. It is a block diagram which shows the example which applied the inter-vehicle distance control apparatus which concerns on Embodiment 1 of this invention to the anti-skid braking system. It is a functional block diagram which shows the internal structure of the constant deceleration control part which concerns on the form of Embodiment 1 of this invention. It is a characteristic view of the deceleration characteristic which concerns on form of Embodiment 1 of this invention. It is a block diagram which shows the structure of the conventional apparatus.

Explanation of symbols

1 vehicle distance detection means, 2 vehicle speed detection means, 4A control means, 4A1 relative speed calculation part, 4A2 target deceleration setting part, 4A3 constant deceleration control part, 4B driver operation detection part, 5 braking means, 6A notification means .

Claims (1)

An inter-vehicle distance detecting means for detecting an inter-vehicle distance from the preceding vehicle;
Vehicle speed detecting means for detecting the own vehicle speed;
A relative speed calculating means for calculating a relative speed based on the inter-vehicle distance;
Target deceleration setting means for setting a target deceleration based on the relative speed, the host vehicle speed and the inter-vehicle distance;
Constant deceleration control means for performing constant deceleration control of the vehicle according to the set target deceleration;
An informing means for informing the driver of the constant deceleration control ,
The constant deceleration control means includes
A distance hysteresis is provided for the safe inter-vehicle distance from the preceding vehicle,
When the vehicle does not perform the constant deceleration control during tracking while providing a safe inter-vehicle distance with the preceding vehicle, the constant deceleration is performed until the inter-vehicle distance with the preceding vehicle reaches a predetermined value. When the constant deceleration control is performed without performing the control, the constant deceleration control is performed until the inter-vehicle distance from the preceding vehicle reaches the predetermined value .

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