JP2992898B2 - Vehicle speed control device - Google Patents

Description

Description: Object of the Invention (Industrial application field) The present invention relates to speed control of a vehicle equipped with a prime mover, and more particularly, to an image pickup screen provided with a photographing means for photographing the front of the vehicle on the vehicle. Vehicle ahead of the vehicle by image processing (hereinafter referred to as the forward vehicle)
The present invention relates to a speed control device for accelerating and decelerating a prime mover such that the distance (hereinafter referred to as an inter-vehicle distance) is maintained at a distance capable of sufficiently maintaining safety in running the vehicle.

(Prior Art) Japanese Patent Application Laid-Open No. Sho 62-153531 discloses one technique for running a vehicle at a constant speed at a speed designated by a driver (driver). On a road with a relatively large number of traveling vehicles, when traveling at a relatively high speed at a constant speed, the distance from the preceding vehicle (inter-vehicle distance) is often shorter than the safe distance. JP-A-64-
In the constant-speed running control disclosed in Japanese Patent No. 66712, a video camera is provided on the vehicle to capture an image of the front of the vehicle, and from a shooting screen, image processing is performed to extract a boundary line of a running lane of the vehicle (hereinafter referred to as “own vehicle”). The intervehicular distance is calculated by extracting the preceding vehicle on the traveling lane, and deceleration is performed so that the intervehicular distance becomes equal to or less than a predetermined value in order to maintain a safe distance between the vehicle and the preceding vehicle.

(Problems to be Solved by the Invention) The above-described constant-speed traveling control is based on setting the traveling speed of the own vehicle to a value set according to the driver's intention. On roads, driving at a speed that matches the overall flow speed of the vehicles on the road, rather than at any speed of the vehicle, is less driver fatigue and less likely to endanger other vehicles. No.

SUMMARY OF THE INVENTION It is an object of the present invention to smoothly travel by automatic speed control in accordance with the flow of vehicles on a road where there are relatively many traveling vehicles.

[Configuration of the invention]

(Means for solving the problem) (1) Photographing means for photographing the front of the vehicle (10 to 17, CPU
1) Distance calculating means (CPU2) for calculating the distance of the vehicle ahead of the traveling lane of the vehicle from a screen captured by the image capturing means (10-17, CPU1), and means for accelerating and decelerating the prime mover mounted on the vehicle ( (SDR, PCV) in the vehicle speed control device: If the distance is long according to the distance calculated by the distance calculation means (CPU2), the means (SDR, PCV) that accelerates and decelerates the motor mounted on the vehicle is accelerated. A speed control means (CPU3) for setting a deceleration when the distance is short; and a release means (CPU3) for releasing the speed control of the speed control means (CPU3) when the distance is less than a predetermined value. Vehicle speed control device.

(2) Imaging means for photographing the front of the vehicle (10 to 17, CPU
1) Distance calculating means (CPU2) for calculating the distance of the vehicle ahead of the traveling lane of the vehicle from a screen shot by the image capturing means (10-17, CPU1), and means for accelerating and decelerating the prime mover mounted on the vehicle (SDR, PCV), the vehicle speed control device comprising: (SDR, PCV) that accelerates and decelerates the motor mounted on the vehicle if the distance is long according to the distance calculated by the distance calculation means (CPU2) Speed control means (CPU3) for setting acceleration to short and deceleration to be short; interrupting vehicle detecting means (CPU2) for detecting an interrupting vehicle to the traveling lane from a screen taken by the imaging means (10-17, CPU1); Releasing means (CPU3) for releasing the speed control of the speed control means (CPU3) in response to the detection of the interrupting vehicle;
A vehicle speed control device comprising:

Signals in parentheses indicate corresponding elements in the embodiment shown in the drawings and described later.

(Operation) (1) First, the image pickup means (10 to 17, CPU1) photographs the front of the vehicle, and the distance of the vehicle ahead of the traveling lane of the vehicle from the screen photographed by the distance calculation means (CPU2) ( (Inter-vehicle distance). However, if the speed control means (CPU3) corresponds to the distance between vehicles and it is long, the motor mounted on the vehicle is added,
Deceleration means (SDR, PCV) are defined as acceleration, and short is defined as deceleration. Therefore, vehicle speed control that places a reasonable distance between the vehicle ahead and the vehicle is realized, and when traveling on a road with a relatively high density of traveling vehicles, the traveling speed automatically adapts to the flow of the vehicle, Driver fatigue is reduced and the possibility of danger to other vehicles is reduced.

Second, when the inter-vehicle distance becomes less than a predetermined value, the release means (CPU3) releases the speed control of the speed control means (CPU3), so that the speed is controlled by the acceleration / deceleration operation of the driver.
When the inter-vehicle distance is extremely short, there is a control error due to the combination of the distance detection accuracy, the speed control accuracy, and the response speed of control, so that a safe inter-vehicle distance cannot be secured. In such a case, the automatic speed control is automatically released,
The reliability of automatic speed control is improved.

(2) While the above-described first operation and effect of (1) are provided, secondly, the interrupting vehicle detecting means (CPU2) detects the interrupting vehicle to the own vehicle traveling lane from the photographing screen. The release means (CPU3) responds to the detection of the interrupting vehicle by controlling the speed control means (CP
Release the speed control of U3).

If another vehicle enters the driving lane, the inter-vehicle distance becomes sharply shorter than before, so that there is a large disturbance to the inter-vehicle distance automatic adjustment traveling for the tracked vehicle (front vehicle). Becomes Here, since the inter-vehicle distance automatic adjustment traveling is canceled, appropriate driving can be performed for the driver interrupt vehicle. Even when there is an interrupting vehicle, it is appropriate to determine whether it is appropriate to target a new preceding vehicle (interrupting vehicle) as a tracking target. We can expect proper driving based on strength and judgment.

Other objects and features of the present invention will become apparent from the following description of embodiments with reference to the drawings.

(Embodiment) FIG. 1a shows a system configuration of an embodiment of the present invention. This embodiment is a speed control device that monitors the traveling direction of a vehicle (own vehicle) equipped with an engine and controls the speed of the own vehicle according to the distance to the preceding vehicle (inter-vehicle distance). In this device, the microprocessor CPU1 and the microprocessor
The CPU 2 processes the image of the vehicle traveling direction by the video camera 15 to process the own vehicle lane, obstacles on the own vehicle lane (vehicles ahead, obstacles), the distance to the obstacle (inter-vehicle distance), and the own vehicle for the obstacle. The relative speed of the vehicle is detected and calculated, and the image is simplified and displayed on the CRT 1 to facilitate the driver's visual recognition. The traveling speed (target value) is set according to the correlation between the distance to the preceding vehicle (expressed only as the preceding vehicle) (inter-vehicle distance) and the relative speed of the own vehicle to the preceding vehicle, the target value is displayed on the character display 2, and the actual traveling is performed. The throttle valve of the engine on the vehicle is opened and closed so that the speed matches the target value. If the deceleration is insufficient by the deceleration due to the closing drive of the throttle valve, a downshift command is issued to the automatic transmission control device 3 to perform a large deceleration with a high engine brake due to the downshift of the automatic transmission.

In this embodiment, the video camera 15 is installed in the vehicle interior at the upper center of the front window of the vehicle, and captures a scene in front of the vehicle. Figures 1b and 1c (Fig. 1b
(IC-IC cross-sectional view) shows how the video camera 15 is mounted.
The video camera 15 is mounted on the support arm 5 of the inside mirror 6 (driver's rearview mirror). The support arm 5 is substantially Y-shaped, and has a through-hole 24 through which an electric cable of the imaging camera 15 passes and a through-hole 25 through which air passes through one branch branch protruding forward of the vehicle from the trunk. I have. Another inside mirror 6 is supported by a branch that protrudes downward. A lens 26, a video camera 15, and a video camera controller 14 are disposed in a relatively large diameter through-hole, which is continuous with the through-hole 24, of the branch that protrudes in the forward direction of the vehicle, from the front of the vehicle. The electric cable connected to the controller 14 passes through the through hole 24 and is connected to the connector 27 at the upper end of the trunk of the support arm 5. The upper end of the through hole 25 through which air passes is connected to an air conditioner (not shown), and a connector 31 is connected to the air pipe 30.
Connected through. The other end of the through hole 25 is open to face the front window glass 8. Support arm 5
A small-diameter open end of a rubber hood 28 having a roughly trumpet shape is connected to the tip of the branch that protrudes toward the windshield 8, and the large-diameter open end of the tip is connected to the front like a suction cup. It is pressed against the glass 8. The hood 28 substantially closes the space between the lens 26 and the windshield 8, that is, the optical path space for photographing the front outside the vehicle, and substantially blocks the space outside the vehicle and the space inside the vehicle. The hood 28 is provided with a small hole 29 for letting the air blown into the hood 28 through the through hole 25 escape into the vehicle. The air that has entered the inner space of the hood 28 through the through-hole 25 exits the hood 28 through the small hole 29, and causes dew condensation (cloudiness) on the inner surface of the windshield 8 and the outer surface of the lens 26 in the hood. To remove water. That is, an antifogging effect on the inner surface of the windshield 8 and the outer surface of the lens 26 is provided. The hood 28 has elasticity,
The propagation of one vibration of the support arm 5 and the windshield 8 to the other is blocked. Cleaned air from the air conditioner is guided by the duct and supplied to the through hole 25 through the air pipe 30. Lens 26 and video camera 15
However, since the wiper 7 is aimed at the front of the vehicle through the area to be cleaned as shown in FIG. 1b, dirt and raindrops on the outer surface of the windshield 8 in front of the lens 26 are removed by driving the wiper 7.

Referring back to FIG. 1a. The video camera 15 is a two-dimensional image sensor, and its video signal is transmitted to an A / D converter 16.
Is converted into a digital image signal of 256 gradations for each pixel, and is written into the image memory 17 of 512 × 512 pixels per frame. The CPU 1 controls the aperture of the video camera 15 and the output of the video signal via the video camera controller 14, and controls the input / output of the A / D converter 16 and the image memory 17.
And synchronously controls the writing process of.

The CPU 2 processes the image signal of the image memory 17 and writes the image signal into the output buffer memory 18. The memory 18 is for storing image signals for one frame for display. The display controller 19 is connected to a CRT driver 20 for driving the color CRT 1, a display driver 21 for driving the character display 2 for speed display, and a buzzer driver 22 for driving the buzzer 4. The CPU 2 processes the image signal of the image memory 17 to cut out the traveling lane (the boundary line on both sides of the traveling lane), cut out the vehicle ahead of the traveling lane, calculate the distance (from the own vehicle) of the preceding vehicle, and Executes image processing such as calculation of relative speed with the own vehicle and various calculations, and outputs the result to CRT1.
The screen shown in FIG. 3a is displayed. Since these image processing and calculation are disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 64-66712, detailed description in this document is omitted. In addition,
On the display screen, the image of the traveling direction and the template ARO indicating the preceding vehicle are displayed in different colors. The information in the character display area in the lower four columns of the screen in FIG. 3a is provided from the microprocessor CPU4 of the constant-speed traveling control device 13. The CPU 2 drives the character display 2 and the buzzer 4.
CPU3 gives to CPU2.

FIG. 1d shows the appearance of an instrument panel in front of the driver's seat of the vehicle. The color CRT 1 and the display 2 are housed and equipped in an instrument cluster.

Referring again to FIG. 1a, the control program is stored in the ROM 11, and the parameter being processed is stored in the RAM 12. The bus controller 10 controls data transfer, address transfer, and the like between the components.

FIG. 1e shows the configuration of the constant speed traveling control device 12. The input ports P1 to P1 of the microprocessor CPU3 which is the main body of the device 12.
A switch is connected to P11 via the interface circuit IOC.
IGS, SW1 to SW10 are connected, and a solenoid driver SDR and a motor driver MDR are connected to the input ports P12 and P13, respectively. The contents of each switch are as follows.

Of these switches, switches SW4 to SW7 are arranged at the center of the steering wheel WHL. The steering shaft connected to the steering wheel WHL is a hollow shaft rotatably supported by a fixed shaft. Since this center portion is fixed to the fixed shaft, the steering wheel 3 rotates. However, the posture does not change.

The switch SW10 is a magnetically responsive reed switch, and a four-pole permanent magnet MAG coupled to the axle is disposed near the switch SW10. The permanent magnet MAG rotates at the same rotation speed as the axle. LP is a stop lamp.

One end of the switch SW1 is connected to a positive pole of the on-board battery BAT via an engine key switch IGS, and the other end is grounded via a stop lamp LP. Switch SW1
Are connected to input ports P1 and P2 of the microprocessor CPU3 via the interface circuit IOC, respectively. When switch SW1 is turned on (closed: on),
If there is no abnormality, the input level of port P1 does not change
The input level of P2 changes from low level L to high level H. However, if the fuse of the battery voltage line is blown, the input level of port P2 does not change and the level of P1 remains high.
To L.

One end of each of the switches SW2 to SW10 is grounded. That is, when the switches are connected (closed: on), the input ports P3 to P9 connected to each other via the interface circuit IOC become L. Note that P11 is an external interrupt input port, and the CPU 3 executes an external interrupt process each time P11 is inverted from H to L.
Detect the opening / closing cycle of 10, calculate the vehicle speed from the detected cycle, and write it to the vehicle speed register.

Around the engine on the vehicle (not shown), a vacuum pump and an actuator having an air flow path switching solenoid valve PCV and a diaphragm for opening and closing a throttle valve are provided. The vacuum pump is provided with a motor VPM, and generates a negative pressure at its output port when the motor VPM is energized. When the electric coil of the air flow switching solenoid valve PCV is energized, the input port of the diaphragm communicates with the output port of the vacuum pump. When the electric coil of the solenoid valve PCV is not energized, the input port of the diaphragm communicates with the atmosphere. CPU3 is
To increase the throttle valve opening (increase the vehicle speed), energize the motor VPM and the solenoid valve PCV to increase the negative pressure in the diaphragm chamber, and maintain the throttle valve opening constant (maintain the vehicle speed constant). Sometimes a motor
Deenergize VPM and continue energizing solenoid valve PCV. When lowering the throttle valve opening (reducing the vehicle speed), the motor VPM and the solenoid valve PCV are deenergized to supply the atmospheric pressure into the diaphragm chamber. Solenoid driver SDR is CPU
In response to the instruction of (3), the electric coil of the solenoid valve PCV is activated / deactivated, and the motor driver MDR activates / deactivates the motor VPM in response to the instruction of the CPU3. In addition, the above-mentioned biasing / de-energizing for the structure of the actuator and the vehicle speed adjustment are
Since it is disclosed in the above-mentioned JP-A-62-153531, detailed description in this document is omitted.

The microprocessor CPU3 of the constant-speed traveling control device 12 performs processing or control of four control modes of "standby mode", "lock-on mode", "inter-vehicle distance control mode" and "constant-speed traveling mode". .

The relationship between transition conditions and transition directions between these modes is
This is shown in blocks in FIG. 2a and in a table in FIG. 2b. Note that
FIG. 2b also shows the content of the display image of the CRT 1 in each mode and the buzzer notification mode at the time of transition between modes.

FIG. 3b shows the respective buzzer activation timings of the buzzer notification mode at the time of transition between modes, and FIG. 3b shows a display timer 1 and a display for blinking a specific image on the screen of the CRT1 to draw the driver's attention. This shows the blink timing of the timer 2. 5a to 7 show the control operation of the CPU 3.
Hereinafter, with reference to these drawings, a control operation of each mode of the CPU 3 will be described.

(I) Standby mode (Fig. 5a) Stabilized power supply RVC with engine key switch IGS closed
Gives a constant voltage to each part of the circuit, the CPU 3 is turned on and a power-on reset is applied, and the CPU 3 initializes its input / output ports and internal memories, counters, registers, etc. (Step 1 in FIG. 5a). Hereinafter, the word “step” is omitted in parentheses.) In this initialization, the same signal as the signal instructing the release of the cruise control is output to the solenoid driver SDR and the motor driver MDR. The opening of the throttle valve by the diaphragm is not performed, and the driver (driver) operates the accelerator to operate the vehicle. Runs. There is no indication of CRT1.

The CPU 3 waits for the condition that the vehicle speed is equal to or higher than the low speed limit, equal to or lower than the high speed limit, and the switch SW is closed (ON) (2-8 in FIG. 5a).

When this condition is satisfied, the alarm 1 is set (9), and the process proceeds to the "lock-on mode". Alarm 1 is
As shown in FIG. 3b, the buzzer 4 is urged once for a short time. In the setting of alarm 1, the buzzer activation timer is started, and the buzzer activation start is output to CPU1,
Enable timer interrupts. The CPU 1 outputs an energization instruction signal to the alarm driver 22 in response to the buzzer activation start signal. After that, when the buzzer activation timer times out, the CPU 3 executes a timer interrupt TIP shown in FIG.
The buzzer activation stop is output to.

(II) Lock-on mode (Figs. 5b & 5c) In this mode, the operating status of the system is displayed to the driver (driver). That is, "AD" is added to CRT1 (Fig. 3a).
Only is displayed and the alarm instruction information (alarm 1, 2 or 3) is deleted (cleared) (10 to 12 in FIG. 5b).

Also, the automatic speed control is released (actuator release =
PCV and VPM are turned off) (13 in FIG. 5b). As a result, the throttle valve is automatically controlled by the speed control system (actuator).
, The driving is released, and the vehicle can be driven only by the accelerator operation by the driver.

The CPU 3 compares the vehicle speed with the low speed limit and the high speed limit (15 and 16 in FIG. 5b), and determines that the vehicle speed is between them.
Instructs PU2 to perform image processing. CPU2 displays on the CRT1 the image in front of the vehicle, which has been simplified and clarified by image processing, and calculates the distance between vehicles, relative speed data, and whether the vehicle crosses the lane boundary. The driving information is given to the CPU 3 (17 in FIG. 5b). FIG. 6 shows the contents of this processing. The screen of CRT1 shows the scene ahead of the vehicle, the template ARO that helps to recognize the vehicle ahead when there is a vehicle on the vehicle driving lane, and “AD” in the character column
Is displayed. A display timer 1 that does not display the template ARO when the preceding vehicle is not detected within the long-distance limit, and specifies the blinking of the display of the “template” and “front vehicle” when displaying the template and the preceding vehicle.
Is set, and alarm 2 is set (5c
Figures 18-22). As a result, the template ARO on the screen shown in FIG. 3a and the preceding vehicle block blink in the mode of the display timer 1 shown in FIG. 3c, and the buzzer 4 sounds intermittently in the alarm 2 timer mode shown in FIG. 3b.

When the vehicle speed falls below the low speed limit or above the high speed limit, or when the switch SW3 is turned off (open), the mode returns to the “standby mode”. To return to the "standby mode" in response to the switch SW3 being turned off, the alarm 1 is set (14 to 16, 31 in FIG. 5b).

When the CPU 3 is in the “lock-on mode” and the inter-vehicle distance is equal to or more than the short distance limit and equal to or less than the long distance limit, the CPU 3 waits for the switch SW6 or SW7 to be turned on (closed) (see FIG. ~ Fig. 5c 24).

Each of the switches SW4 to SW7 is a one-touch switch (a momentary switch that closes only when pressed and returns to open when the pressing force is removed). When the driver (driver) wants to perform the inter-vehicle distance automatic control traveling, he / she operates the switch SW7 one-touch when the inter-vehicle distance to the preceding vehicle and the own vehicle speed are desired. When the user wants to travel at a constant speed, the switch SW6 is operated with one touch when the vehicle speed is desired.

When the switch SW7 is turned on, the CPU 3 sets the alarm 1 (25 in FIG. 5c), writes the vehicle speed at that time into the reference vehicle speed register (26), and writes the inter-vehicle distance at that time into the reference distance register. (27) The process proceeds to the "inter-vehicle distance control mode".

When the switch SW6 is turned on, the CPU 3 sets the alarm 1, writes the vehicle speed at that time in the reference vehicle speed register (29), and proceeds to the "constant speed running mode".

(III) Inter-vehicle distance control mode (Figs. 5d, 5e & 5f
CPU3 First, CPU3 instructs CPU2 to display "AD", "vehicle distance" and "vehicle ahead" in the character columns on the screen of CRT1, and instructs to erase the display of "constant speed driving", and alarm instruction information Is reset (32-34 in FIG. 5d). Next, the deceleration α is calculated from the data in the reference vehicle speed register and the data in the reference distance register.
Is calculated.

Several examples of the deceleration α are shown in FIG. 4b. Distance L (m)
Is generally the control distance for the vehicle speed V (Km / h) (the travel distance from when the brake is depressed at the vehicle speed until when the vehicle safely stops)
And deceleration is α, L = V ² /
(2α). In Japan, it is usually taught that at V = 100Km / h, L = 100m, and at 60km, the distance between vehicles is 40m. For example, it is taught at a driving school.
It is assumed that However, in road driving, for example, in addition to the delay and speed of the driver's danger determination, the delay and speed from the danger determination to the brake application, and the delay and speed from the brake application to the start of braking, etc. There is a difference in the coefficient of friction, and the own vehicle applies the brake after the front vehicle has applied the brake in many cases, and the preceding vehicle also applies the brake and proceeds to some extent without stopping immediately. The vehicle is driven at a longer distance or at a shorter distance than the above-mentioned distance.

In this embodiment, such a tendency of the driver is estimated by the vehicle speed (the value of the reference vehicle speed register) and the inter-vehicle distance (the value of the reference inter-vehicle distance register) when the driver operates the switch SW7.

In this case, the speed is a single value. However, the speed of the preceding vehicle increases and decreases, and accordingly, the target inter-vehicle distance must be updated to be longer or shorter. If not, if the speed of the preceding vehicle increases, the speed of the own vehicle also increases, and the following distance is the same as the previous value.
Even when driving at high speeds, the vehicle will be driven with a short inter-vehicle distance to increase the danger, or at low speeds, the vehicle will be followed up with a long inter-vehicle distance, allowing interrupted vehicles one after another, and the vehicle will decelerate whenever there is an interrupted vehicle Problems can occur.

Therefore, in this embodiment, the CPU 3 writes the vehicle speed of the reference vehicle speed register, in which step 26 of FIG. 5c is written in V of L = V ² / (2α), and L in FIG. Substitute the written data of the reference inter-vehicle distance register to calculate α. That is, an inter-vehicle distance calculation formula L = V ² / (2α) estimated from the driver's tendency to follow the preceding vehicle (contents of the reference vehicle speed register + contents of the reference inter-vehicle distance register) is estimated (35 in FIG. 5d). Then, in order to enhance the safety, the calculated α is compared with the allowable maximum value, and the α calculated that the former is equal to or larger than the latter is updated to the allowable maximum value (38).

With α determined in this way, the following formula L = V ² /
(2α) is determined (37 in FIG. 5d). Then, roughly speaking, while the “inter-vehicle distance control mode” is continued thereafter, while repeatedly detecting the inter-vehicle distance La, the target inter-vehicle distance L corresponding to the ever-changing vehicle speed is calculated as described above. calculated by L = V ² / (2α) as defined in the detected inter-vehicle distance La is to meet the target inter-vehicle distance L, for opening and closing the throttle valve. By the determination of the target inter-vehicle distance L, the vehicle speed V versus the inter-vehicle distance characteristic according to the driving pattern and driving skill of the driver is automatically established, so that the inter-vehicle distance control that can meet the needs of the driver can be performed. Realize.

Since α is limited to the maximum allowable value or less as described above, automatic driving corresponding to a dangerous driving pattern such as running at high speed with a very short inter-vehicle distance cannot be realized.

Now, it is assumed that the following formula L = V ² / (2α) is determined as described above. The CPU3 determines that the vehicle speed is above the low-speed limit and below the high-speed limit, the preceding vehicle is above the short-range limit and below the long-range limit, and other requirements for automatic speed control cancellation (SW1
While the on, SW8 on, SW9 on, own vehicle lane change, SW4 on, forward vehicle lane change or interrupted car are not established, the image is cut out (41 in FIG. 5e; According to the inter-vehicle distance La detected by the CPU 2 and the instantaneous vehicle speed, the inter-vehicle distance calculation formula L = V ² / (2
α) to calculate the target inter-vehicle distance L corresponding to the vehicle speed (5 in FIG. 5f).
2) The inter-vehicle distance La detected by the CPU 2 is calculated as the target inter-vehicle distance L.
(53 in FIG. 5f), the speed increase control (54) is performed when La exceeds L, and the deceleration control (54) when La is less than L.
Perform 5). These speed-up control and deceleration control are disclosed in the above-mentioned JP-A-62-153531.

During the deceleration control, the degree of risk D = K · Vr / La is calculated. K is a constant, and Vr is the relative speed between the preceding vehicle and the own vehicle (own vehicle speed-forward vehicle speed). Several relative speeds Vr ₁ , Vr ₂ , Vr
FIG. 4a shows the relationship between the inter-vehicle distance and the risk D at ₃ (both are positive values). The higher the relative speed and the shorter the inter-vehicle distance, the greater the risk D is (the higher the risk).

When the risk D exceeds the set value Dbk, the CPU 3 sends a downshift instruction signal to the automatic transmission control device 3 (see FIG. 5h).
88,89). Upon receiving this signal, the automatic shift control device 3 shifts from the speed stage at that time. That is, the engine is braked by the shift down operation of the automatic transmission.

In the following cases, the CPU 3 informs the driver that the control condition has changed by displaying an alarm and / or CRT 1 and draws attention to the driver to change the mode.

-Transition to lock-on mode--When the inter-vehicle distance La is less than the short distance limit (fixed value) (44 in Fig. 5e-60-63 in Fig. 5f)-The preceding vehicle being captured is the own vehicle When the vehicle deviates from the lane (detection is 102, 103 in FIG. 6; transition is 50-60 to 63 in FIG. 5f).

-When the vehicle changes lanes (detection of 97B and 97 in Fig. 6)
D and 48A in FIG. 5f. The transitions are 48A, 48B-60 to 6 in Fig. 5f.
3).

-When there is an interrupted vehicle (detection is 104, 105 in Fig. 6; transition is 51-60 to 63 in Fig. 5f).

When the brake is operated (47 in FIG. 5e to 60 in FIG. 5f)
~ 63).

When the mode transits to the lock-on mode, the speed control is released (PCV off and VPM off) in step 13 of FIG. 5b.

-Transition to the constant speed mode-When the inter-vehicle distance La exceeds the long distance limit (fixed value) (58, 59 in Fig. 5e).

-When the vehicle speed exceeds the high speed limit (fixed value) (58, 59 in Fig. 5e).

(IV) Constant-speed running mode (FIGS. 5g and 5h) First, the CPU 3 instructs the CPU 2 to display "constant-speed running" in a character column on the screen of the CRT 1 (67 in FIG. 5g). Next, the CPU3 first outlines the vehicle speed, which is above the low speed limit and below the high speed limit, the preceding vehicle is above the short distance limit and below the long distance limit, and the other requirements (SW1 ON, SW4 ON) for releasing the constant speed driving are satisfied. While not, the vehicle speed V is compared with the reference vehicle speed of the reference vehicle speed register (85 in FIG. 5h). If the vehicle speed V is lower than the reference vehicle speed, the speed increasing control (54) is performed, and the vehicle speed V is equal to or higher than the reference vehicle speed. And deceleration control (55). These speed-up control and deceleration control are disclosed in the above-mentioned JP-A-62-153531.

When the vehicle shifts to the constant speed traveling mode from the "vehicle width distance control mode", the reference vehicle speed in the reference vehicle speed register indicates the vehicle speed when the driver operates the switch SW7 (see 24 in FIG. 5c).
27), in the constant-speed traveling mode, the traveling is to maintain the speed.

While executing the constant speed traveling mode, the CPU 3 sets the danger level D
= K · Vr / La, and this risk D is a relatively low value D
The constant speed control is continued as long as TH1 (see FIG. 4a) or less (81-85 to 89 in FIG. 5h).

While the danger level D is equal to or higher than DTH1 and equal to or lower than the upper limit value DTH2, D is written to the reference value register for volume setting, alarm 2 is set, the template ARO is attached to the vehicle in front of the CRT1 screen, and " Vehicles ahead "and display these in 3c
A display mode that blinks at the timing of the display timer 1 shown in the figure is set (83, 84 in FIG. 5h), and the constant-speed running is continued. By setting the alarm 2, the CPU 3 executes a "timer interrupt process" (TIP) shown in FIG. 7, thereby continuously energizing the buzzer 4 at the timing of the alarm 2 timer shown in FIG. 3b. Corresponding to the danger level D in the volume setting reference value register, the higher the level, the higher the volume is set (115 to 124 in FIG. 7). I do.

In the following cases, the CPU 3 informs the driver that the control condition has changed by displaying an alarm and / or CRT 1 and draws attention to the driver to change the mode.

-Transition to lock-on mode--When the degree of danger D exceeds the upper limit value DTH2, that is, when there is a vehicle ahead and the relationship between the inter-vehicle distance and the relative speed is in a danger area (for example, the vehicle speed is higher than that of the vehicle in front, and When the vehicle enters a short distance), set alarm 3 and enter CRT1
Is displayed in the character column of, a display mode in which the display blinks at the timing of the display timer 2 in FIG. 3c is set, and a transition is made to the “lock-on mode” (77, 78 in FIG. 5h).
In the “lock-on mode”, the cruise is released (5b
13).

When the switch SW1 or SW4 is operated (68 in FIG. 5g;
69-95). The alarm 1 activates the buzzer 4.

-Transition to the standby mode--When the switch SW3 is opened (70-94 in Fig. 5g).
The alarm 1 activates the buzzer 4.

-When the vehicle speed is higher than the high speed limit or lower than the low speed limit (71, 72-92-93 in Fig. 5g). The alarm 3 activates the buzzer 4 and the "timer running" in the character column on the CRT1 screen flashes on the display timer 2.

-Transition to inter-vehicle distance control mode-If the switch SW7 is operated when the inter-vehicle distance is equal to or greater than the short distance limit and equal to or less than the long distance limit, the buzzer 4 is activated by the alarm 1 and the mode transits to the inter-vehicle distance control mode (No. 76-79-80-90 in Figure 5h).

The contents of “image extraction” (17) in FIG. 5b, “image extraction” (41) in FIG. 5e, and “image extraction” (73) in FIG. 5g are the same, and the outline is shown in FIG. This is mainly CPU2
Runs. In this "image cutout" (73), the own vehicle lane is cut out, the preceding vehicle is cut out, the distance (inter-vehicle distance) is calculated by the image processing disclosed in JP-A-64-66712.
And the relative speed Vr (96,97A, 98,100, RV
A). In addition to this, the CPU 2 determines whether the vehicle crosses the lane boundary from the position of the cut lane on the screen,
If it is straddling, 1 is written to the turn flag register, and if it is not straddling, the turn flag register is cleared (6th
97B, 97C, 97D in the figure). When a preceding vehicle is detected on the own vehicle lane, a distance (inter-vehicle distance) calculation is performed. When this calculation is performed, the inter-vehicle distance calculated this time is compared with the previously calculated inter-vehicle distance to determine whether the preceding vehicle has changed the lane. Also, it is determined whether there is an interrupting vehicle (102, 104), and when the preceding vehicle changes lanes, 1 is written into the preceding vehicle lane change flag register (103) and 1 is written into the interrupting vehicle flag register 105 (103). Ten
Five). If no vehicle is detected in the vehicle's lane,
Clear the preceding vehicle detection flag register, interrupt vehicle flag register, and preceding vehicle lane change flag register (106 to 10
8).

The CPU 2 gives the inter-vehicle distance data and the relative speed data and the data of the turn flag register, the preceding vehicle detection flag register, the preceding vehicle lane change flag register and the interrupt vehicle flag register to the CPU 3, and displays the foreground image on the CRT 1. .

The display in the character column of CRT1 is `` A.
D. ”,“ inter-vehicle distance ”,“ constant speed driving ”, and“ vehicle ahead ”
There are four types. “AD” is lit and displayed in the lock-on mode, the following distance control mode, and the constant speed traveling mode.
The “vehicle distance” is illuminated and displayed in the vehicle distance control mode. “Constant speed traveling” is lit and displayed in the constant speed traveling mode. “Front vehicle” is illuminated when a vehicle ahead is detected below the long distance limit in the own vehicle lane. Note that these displays may be illuminated by individual lamps.

Next, the buzzer 4 in each of the above-described modes and the manner of notifying the driver by the character columns on the screen of the CRT 1 will be summarized.

* Lock-on mode * <When there is no vehicle ahead> ・ A.D. lights up.

・ The "inter-vehicle distance", "constant speed driving" and "vehicle ahead" are turned off.

・ Buzzer 4 stops.

<When a vehicle ahead is present>-Lights "A.D.".

-"Front vehicle" blinks on display timer 1.

-Turns off "Constant speed driving" and "Vehicle distance".

-The display timer 1 blinks the template ARO superimposed and displayed on the position indicating the vehicle ahead of the foreground image of CRT1.

・ When the risk D is between the set values DTH1 and DTH2,
The alarm 2 activates the buzzer 4 intermittently, but the sound volume increases as D increases.

* Constant speed mode * <When there is no vehicle in front> ・ Lights “A.D.” and “Constant speed”.

・ "Flight ahead" and "Distance between vehicles" are turned off.

・ Turn off template ARO.

・ Buzzer 4 stops.

<When a vehicle ahead is present> ・ Lights "A.D." and "Constant speed".

-Turns off "inter-vehicle distance".

-"Front vehicle" and template ARO are displayed blinking on display timer 1.

・ When the risk D is between the set values DTH1 and DTH2,
Although the buzzer 4 is continuously energized by the alarm 2, the volume is increased as the D is higher.

* When transiting from the constant-speed running mode to the standby mode, lock-on mode or inter-vehicle distance control mode *-The buzzer 4 is continuously energized at a high speed by the alarm 3 and stopped after a predetermined time.

"Constant speed running" flashes on the display timer 2 at high speed and turns off after a predetermined time.

* Vehicle distance control mode *-"AD", "Front vehicle" and "Vehicle distance" are illuminated.

・ Continuously displays the template ARO indicating the vehicle ahead on the CRT1 screen.

・ "Constant speed driving" is turned off.

・ Stop buzzer 4.

* When transiting from the inter-vehicle distance control mode to the standby mode, lock-on mode or constant-speed traveling mode *-The buzzer 4 is continuously energized at a high speed by the alarm 3 and then stopped.

-The "inter-vehicle distance" blinks at high speed on the display timer 2 and turns off after a predetermined time.

* Manual mode display * ・ In response to the operation of the switch SW4, SW5, SW6 or SW7, when transitioning to the mode corresponding to the operated switch, the buzzer 4 is activated by the alarm 1 in one shot.

As described above, the CPU 3 sets at least one of the alarms 1 to 3 and the display timers 1 and 2 and starts the internal timer by the CPU 3 to activate the buzzer and the CRT 1 display for notifying the driver. By enabling interrupts, CPU3
Is executed in the "timer interrupt process" shown in FIG.

According to the control operation of the CPU 3 described above, in the lock-on mode in which the own vehicle traveling lane and the preceding vehicle are displayed on the CRT 1, the driver appropriately sets the following distance to the preceding vehicle and the own vehicle speed is appropriate. When the switch SW7 is operated, the vehicle speed at that time is written into the reference vehicle speed register, and the following distance is written into the reference distance register (24 to 27 in FIG. 5c), and the vehicle speed control in the following distance control mode is started. . In this inter-vehicle distance control mode, a target inter-vehicle distance calculation function L = V ² / (2α) of the vehicle speed versus inter-vehicle distance characteristic based on the contents of the reference vehicle speed register and the inter-vehicle distance register is determined (35 to 3 in FIG. 5d).
7). Thereafter, the target inter-vehicle distance L corresponding to the instantaneous vehicle speed is calculated according to the function, and the throttle valve is opened (L <La) so that the inter-vehicle distance La detected by the CPU 2 matches the target inter-vehicle distance L. ) Or closing drive (when L> La) (85-87 in FIG. 5h). In addition, the risk D = K · based on the own vehicle speed−the forward vehicle speed = Vr and the inter-vehicle distance La.
When Vr / La is calculated and the risk D exceeds the upper limit DTH2,
The transmission is shifted down to lower gears, and strong engine brakes act on the vehicle, increasing deceleration (88, 89 in FIG. 5h).

When the inter-vehicle distance La exceeds the long-distance limit or when the vehicle speed exceeds the high-speed limit, the vehicle automatically runs at a constant speed, and the vehicle speed is maintained at the vehicle speed written in the reference vehicle speed register (45 in FIG. 5e). , 46-58-59-67 to 5h in Fig. 5g
Figures 85-87).

When the driver operates the switch SW7 while the preceding vehicle is equal to or more than the short distance limit and equal to or less than the long distance limit while traveling at a constant speed, the target inter-vehicle distance calculation function L = V ² / set in the preceding inter-vehicle distance control mode. The target inter-vehicle distance L is calculated based on (2α) and the vehicle speed is controlled such that the actual inter-vehicle distance becomes the distance L. The above-described inter-vehicle distance control mode is executed again.

As described above, even when the vehicle lane is in the inter-vehicle distance control mode, when the own vehicle lane is in a state where the constant speed traveling is more preferable, the constant speed traveling is automatically executed. Even when the vehicle is traveling at a constant speed, the switch to the inter-vehicle distance control mode is made when the switch SW7 is closed in a state where the inter-vehicle distance control mode is more preferable because the vehicle in front is nearer. Mode / constant speed running mode). Nevertheless, the switching between them is reasonable for vehicle operation,
The automatic speed control function of the vehicle is greatly improved, and the driver's workload is reduced.

In the above-described embodiment, when the risk D exceeds the upper limit DTH2 in the inter-vehicle distance control mode and the constant speed traveling mode, the transmission gear is changed to a lower speed than the speed at which the engine brake is effective. According to the second embodiment of the present invention, in a vehicle having a mechanism and a control means for automatically adjusting the wheel brake pressure for anti-skid control or traction slip control, for example, the degree of danger D is set to the upper limit DTH2. Is exceeded, the data indicating the brake pressure corresponding to the degree of danger D is given to the brake pressure control means, and the brake pressure is applied to the wheel brake so that the deceleration is actively performed not only by the engine brake but also by the wheel brake. .

〔The invention's effect〕

As described above, according to the first and second aspects of the present invention,
The imaging means (10 to 17, CPU1) photographs the front of the vehicle, and calculates the distance (inter-vehicle distance) of the vehicle in front of the traveling lane of the vehicle from the screen photographed by the distance calculation means (CPU2). However, if the speed control means (CPU3) corresponds to the inter-vehicle distance and is longer, the means for accelerating and decelerating the prime mover mounted on the vehicle (SD
R, PCV) is defined as acceleration, and short is defined as deceleration. Therefore,
Vehicle speed control that places a reasonable inter-vehicle distance with the vehicle ahead is realized, and when traveling on a road with a relatively high density of traveling vehicles, the traveling speed automatically adapts to the flow of the vehicle, Fatigue is reduced and the possibility of danger to other vehicles is reduced.

According to the first aspect of the present invention, when the inter-vehicle distance becomes less than the predetermined value, the release means (CPU3) releases the speed control of the speed control means (CPU3), so that the speed is controlled by the acceleration / deceleration operation of the driver. . When the inter-vehicle distance is extremely short, there is a control error due to a combination of the distance detection accuracy, the speed control accuracy, and the response speed of control, so that a safe inter-vehicle distance cannot be secured. In such a case, the automatic speed control is automatically canceled, so that the reliability of the automatic speed control is improved.

According to the second invention of the present application, the interrupting vehicle detecting means (CPU
3) detects an interrupted vehicle to the own vehicle traveling lane from the photographing screen, and the release means (CPU3) releases the speed control of the speed control means (CPU3) in response to the detection of the interrupted vehicle. If another vehicle enters the driving lane, the inter-vehicle distance will be sharply shorter than before.
Is a large disturbance to the automatic inter-vehicle distance adjustment traveling. Here, the inter-vehicle distance automatic adjustment traveling is canceled, so that the driver can appropriately drive the interrupted vehicle. Even when there is an interrupting vehicle, it is appropriate to determine whether it is appropriate to target a new preceding vehicle (interrupting vehicle) as a tracking target. We can expect proper driving based on strength and judgment.

[Brief description of the drawings]

FIG. 1a is a block diagram showing the configuration of one embodiment of the present invention. FIG. 1b is a perspective view of a front window of a vehicle equipped with the vehicle speed control device shown in FIG. 1a. FIG. 1c is an enlarged sectional view taken along line IC-IC of FIG. 1b. FIG. 1d is a perspective view of an instrument panel at a front portion of a driver seat of a vehicle equipped with the vehicle speed control device shown in FIG. 1a. FIG. 1e is a block diagram showing the configuration of the constant speed traveling control device 12 shown in FIG. 1a. FIG. 2a is a block diagram showing a relationship between a control mode of the vehicle speed control device shown in FIG. 1a and transition between modes. FIG. 2b is a plan view showing the relationship between the control modes of the vehicle speed control device shown in FIG. 1a and the transition between modes, and the relationship between display and buzzer notification in each control mode. FIG. 3a is an enlarged plan view showing a display screen of the CRT 1 shown in FIG. 1a. FIG. 3b is a time chart showing the timing of energizing the buzzer 4 shown in FIG. 1a. FIG. 3c is a time chart showing the lighting display timing of the character column of the screen of the CRT 1 shown in FIG. 1a. FIG. 4a is a graph showing a degree of risk D determined by an inter-vehicle distance La and a speed difference Vr of the own vehicle with respect to a preceding vehicle. FIG. 4b is a graph showing the relationship between the vehicle speed and the inter-vehicle distance. 5a, 5b, 5c, 5d, 5e, 5f,
Figures 5g and 5h show the microprocessor shown in Figure 1e.
6 is a flowchart illustrating a control operation of the CPU 3. FIG. 6 is a flowchart showing an outline of the photographed image processing and the arithmetic processing performed by the microprocessor CPU2 shown in FIG. 1a. FIG. 7 is a flowchart showing a buzzer activation process and a display activation process of the microprocessor CPU3 shown in FIG. 1e. 1: CRT, 2: Character display 4: Buzzer, 5: Support arm 6: Inside mirror, 7: Wiper 8: Front window glass, 9: Roof 10: Bus controller, 11: ROM 12: RAM, 13: Constant speed running Control unit 14: Video camera controller, 15: Video camera 16: A / D converter, 17: Image memory 18: Output buffer memory, 19: Display controller 20: CRT driver, 21: Display driver 22: Buzzer driver, 23: Arm Leg 24: Through hole, 25: Through hole 26: Lens, 27: Connector 28: Hood, 29: Small hole 30: Pipe, CPU1 to CPU3: Microprocessor PCV: Solenoid valve, VPM: Motor SDR: Solenoid driver, MDR: Motor Driver IGS, SW1 to SW10: switch, LP: ramp (10 to 17, CPU1: imaging means) (CPU2: distance calculation means, forward vehicle tracking means, lane change detection means, interrupt vehicle detection means) (SDR, PCV: (Means to increase and decrease the prime mover) (CPU3: Speed Your means, release means) (SW1: brake detecting means)

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-1-281600 (JP, A) JP-A-3-277988 (JP, A) JP-A-61-115730 (JP, A) JP-A-3-115 296200 (JP, A) JP-A-60-154920 (JP, A) JP-A-4-12143 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B60K 31/00-31 / 18 F02D 29/00-29/06 F02D 41/00-41/40 B60K 41/00-41/28 G05D 1/02

Claims (2)

(57) [Claims] 1. An image pickup means for photographing the front of a vehicle, a distance calculating means for calculating a distance of a vehicle ahead of a traveling lane of the vehicle from a screen photographed by the image pickup means, and a motor mounted on the vehicle to accelerate and decelerate. Means for controlling the speed of the prime mover mounted on the vehicle when the distance is long, corresponding to the distance calculated by the distance calculating means; And a release unit that releases the speed control of the speed control unit when the distance is less than a predetermined value. 2. An image pickup means for photographing the front of a vehicle, a distance calculating means for calculating a distance of a vehicle ahead of a traveling lane of the vehicle from a screen photographed by the image pickup means, and a motor mounted on the vehicle for accelerating and decelerating. Means for controlling the speed of the motor mounted on the vehicle when the distance is long, the speed is determined to be acceleration, and when the distance is short, the speed is determined to be deceleration corresponding to the distance calculated by the distance calculation means. Means; an interrupting vehicle detecting means for detecting an interrupting vehicle to the driving lane from a screen imaged by the imaging means; and a releasing means for releasing the speed control of the speed control means in response to the detection of the interrupting vehicle; A vehicle speed control device comprising: