JPH11125535A - Method and apparatus for displaying vehicle speed - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate recognition of a danger by simultaneously displaying on the same display screen actual speed of a preceding vehicle and a measured distance between the preceding vehicle and its own vehicle correspondingly. SOLUTION: A display control circuit receives, from an arithmetic circuit, signals indicating actual speed of its own vehicle, calculated speed of a preceding vehicle and a measured distance between the vehicles and reads vehicle image data from a memory. The preceding vehicle and its own vehicle are displayed respectively at positions B, C at both lower ends of a display screen A, the calculated speed of the preceding vehicle is displayed at a position D above an image of the preceding vehicle, and the actual speed of its own vehicle is displayed at a position E above an image of its own vehicle. Further, the measured distance between the vehicles is displayed at a position F between the positions D, E. In addition, the display control circuit changes a distance L between the images of the preceding vehicle and its own vehicle according to the measured distance between the vehicles. Thus how dangerous a current status can be easily known.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a collision with a vehicle in front by emitting a laser beam to the front of the vehicle, measuring the distance between the vehicle and the vehicle in front, and issuing an alarm when the vehicle approaches the vehicle in front. The present invention relates to a vehicle speed display method and an apparatus for displaying the absolute vehicle speed (actual vehicle speed) of the preceding vehicle, the inter-vehicle distance between the preceding vehicle and the own vehicle (measured inter-vehicle distance) on a single display, and the like.

[0002]

2. Description of the Related Art As a device having a function of detecting (or calculating) a vehicle speed, an inter-vehicle distance, and the like of a preceding vehicle, there is a collision prevention device, for example. FIG. 4 is a block diagram showing a configuration example of such a collision prevention device.

In FIG. 1, reference numeral 1 denotes a distance detecting unit which detects a distance between an own vehicle and an obstacle by using a laser beam emitted from a laser diode (hereinafter referred to as an LD) 13, and 2 denotes a vehicle speed sensor 31. The traveling state detection unit detects the traveling state of the own vehicle such as the own vehicle speed by the method described above.

[0004] Reference numeral 3 designates a distance detection command to the distance detection unit 1, and based on the distance information returned in response thereto and the vehicle speed information detected by the traveling state detection unit 2, Calculates the relative speed with respect to the preceding vehicle and other obstacles, determines whether the obstacle is a stationary or moving object, and determines the vehicle speed (absolute speed), the relative speed, and the idle running time until the brake is applied. The signal processing unit determines whether there is a possibility of collision between the host vehicle and an obstacle based on a distance setting or the like set according to individual differences of the vehicle.

[0005] 4 is based on information from the signal processing unit 3,
An alarm notifying unit that displays the distance between the host vehicle and the obstacle on a distance indicator 51 and that issues an alarm with an alarm 52 when the signal processing unit 3 determines that there is a possibility of collision with the obstacle. It is.

Next, the operation of the above device will be described. The vehicle speed signal of the own vehicle detected by the vehicle speed sensor 31 is output to the signal processing unit 3.
When the vehicle speed calculated based on the vehicle speed signal is 35 Km / h or more,
A distance detection command signal is sent to the distance detection unit 1.

In the distance detecting section 1, the distance detection command signal is received by the drive signal generation circuit 11, and the drive signal generation circuit 11 sends an LD emission signal of a constant frequency shown in FIG. Based on the received LD light emission signal (a), the LD switching driver 12 performs the operation shown in FIG.
The signals shown in (c) and (d) are transmitted, and the LD-L, LD-C, and LD-R of the LD array 13 emit light at the same intensity at all times.

The laser beam from the LD-L of the LD array 13 is directed to the front left of the vehicle, the laser beam from the LD-C is directed forward, and the laser beam from the LD-R is directed to the front right. Emitted through the LD-
The laser beam of C is used to detect an obstacle ahead, the laser beam of LD-L is used to detect an interrupted vehicle from the left lane, and the laser beam of LD-R is used to detect an interrupted vehicle from the right lane.

Light reflected from an obstacle is collected by a light receiving lens 15 and received by a photodiode (hereinafter referred to as PD) 16. This light receiving signal is sent to the amplifier circuit 17, which amplifies the signal and outputs the signal B shown in FIG.

The reference signal generation circuit 18 outputs a reference voltage V0 shown in FIG. Comparison circuit 1
Reference numeral 9 denotes an output signal (e) of the amplifier circuit 17 and the reference voltage V
By comparing the level with 0, a reflected signal from an obstacle is extracted, and an obstacle detection pulse signal shown in FIG.

The counter 20 has L as shown in FIG.
At the rise of the D light emission signal (a), the reference pulse generation circuit 21
The counting of the clock pulse signal supplied from the controller is started, and the counting is stopped at the rising edge of the obstacle detection pulse signal (f) based on the reflection signal from the obstacle. Find distance information,
It is sent to the arithmetic circuit 41 of the signal processing unit 3.

Next, a method of determining the possibility of collision in the arithmetic circuit 41 of the signal processing unit 3 will be described with reference to a flowchart shown in FIG. First, when the power is turned on,
Proceeding to the START step, C constituting the arithmetic circuit 41
Initial settings of PU, RAM, etc. are performed. Next, in step ST11, the counter 20 of the distance detection unit 1 is
From the vehicle speed sensor 31 of the traveling state detection unit 2 to the vehicle speed signal indicating the information of the own vehicle speed Vf.

In step ST12, the arithmetic circuit 41
Converts the distance signal R into a display signal and outputs the distance
To display the distance R. Next, step ST1
3 to calculate a relative speed (d / dt) R between an obstacle such as a preceding vehicle and the host vehicle by using a calculation method such as a least squares method, and calculate a vehicle speed Va of the preceding vehicle. , And the relative speed (d / dt) R.

In this calculation, (d / dt) R <0
In the case of (d / dt) R, the distance R decreases and approaches the obstacle, and when (d / dt) R> 0, the distance R increases. = 0 indicates that there is no change in the distance R.

When judging the possibility of collision with an obstacle, the initial speed of the own vehicle is Vf (m / s), and the initial speed of the obstacle (preceding vehicle) is Va (m / s). Assuming that the deceleration performance is α (m / s ² ), the own vehicle set by the distance setting switch 42 brakes the difference between the stop distance Vf ² / 2α of the own vehicle and the stop distance Va ² / 2α of the preceding vehicle. Time T
The distance R shown in the equation (1), which is obtained by adding the free running distance Vf · Td based on d, is a reference for collision determination.

[0016]

(Equation 1)

Therefore, first, at step ST14, the relative speed (d / dt) R is compared with the own vehicle speed Vf to obtain-(d / dt).
dt) If R ≒ Vf, that is, if the obstacle is regarded as a road stop, the process proceeds to step ST15, and since Va = 0 in the equation (1), the driving law according to the following equation (2) is used. Determine the risk of collision.

[0018]

(Equation 2)

If equation (2) holds, there is a danger of collision with an obstacle, and the process proceeds to step ST18, where an alarm signal is generated and sent to the alarm notifying unit 4, and the alarm 52 , And warns of danger avoidance.

On the other hand, as a result of the determination in step ST14,
If not-(d / dt) R ≒ Vf, the obstacle is a preceding vehicle traveling on the road ahead, and the danger judgment should be made in accordance with equation (1). However, since the calculation accuracy of the relative speed (d / dt) R may not be strictly obtained, the calculation error may cause a false alarm. Therefore, in the case of a preceding vehicle in which an obstacle moves, the relative speed is determined in step ST16. (D
/ Dt) It is first determined whether R is equal to or higher than a predetermined speed C (m / sec).

As a result, when (d / dt) R ≧ C, the relative speed is high and the vehicle is approaching rapidly, so that the preceding vehicle is regarded as infinitely close to a stationary object, and the process proceeds to step ST15. With the same logic as that of the stopped obstacle, the alarm output is determined by the discriminant equation (2).

The result of the determination in step ST16 is (d
/ Dt) If R <C, it is considered that the relative speed is low and the vehicle is running normally following the vehicle at a constant inter-vehicle distance, and the own vehicle speed Vf
Since the vehicle speed Va is substantially equal to the preceding vehicle speed, the equation (1) becomes the following equation (3). In step ST17, the danger of a collision is determined by the equation (3). If the condition is satisfied, an alarm is issued in step ST18.

[0023]

(Equation 3)

[0024]

However, in such a collision prevention device, the distance between vehicles is displayed, and an alarm is issued only when a possibility of collision occurs.
If the speed relationship between your vehicle and the vehicle in front is the same, it is difficult to tell whether your vehicle is gradually approaching or leaving, and it is difficult to know how dangerous it is. There was a problem that there was.

The present invention has been made to solve the above-described problems, and displays at least the actual vehicle speed of the preceding vehicle and the measured inter-vehicle distance between the preceding vehicle and the own vehicle on a single display screen. Thus, it is an object of the present invention to obtain a vehicle speed display method and a vehicle speed display method capable of easily ascertaining the degree of danger.

[0026]

According to a first aspect of the present invention, at least one actual screen speed of a preceding vehicle and a measured inter-vehicle distance between the preceding vehicle and the own vehicle are displayed on one display screen. Are displayed at the same time.

According to the second aspect of the invention, the actual vehicle speed of the preceding vehicle, the measured inter-vehicle distance between the preceding vehicle and the own vehicle, and the actual vehicle speed of the own vehicle are displayed on one display screen in association with each other. The measured inter-vehicle distance is displayed at a position between an actual vehicle speed display of the preceding vehicle and an actual vehicle speed display of the host vehicle.

According to the third aspect of the invention, two vehicle images are displayed on a display screen in front of and behind a straight line, and the interval between the two vehicle images arranged in front of and behind the straight line is set to the measured inter-vehicle distance. It will be adjusted accordingly.

According to a first aspect of the invention, there is provided a vehicle speed display device, comprising: detecting means for detecting an actual vehicle speed of a host vehicle, an actual vehicle speed of a preceding vehicle, and a measured inter-vehicle distance between the host vehicle and the preceding vehicle; Display means for displaying the actual vehicle speed and the measured inter-vehicle distance, and controlling the display content of the display means according to the actual vehicle speed of the preceding vehicle detected by the detecting means and the measured inter-vehicle distance between the host vehicle and the preceding vehicle. Display control means.

According to a second aspect of the present invention, the host vehicle moves in front of the host vehicle in accordance with the actual vehicle speed of the host vehicle, the actual vehicle speed of the preceding vehicle, and the measured inter-vehicle distance between the host vehicle and the preceding vehicle. The vehicle is provided with a warning unit for warning that the vehicle will collide with the vehicle.

According to a third aspect of the present invention, there is provided a memory for storing vehicle image data, wherein the display control means reads the vehicle image data from the memory, and the display control means reads the vehicle image data from the memory.
The two vehicle images are displayed together with the actual speed of the own vehicle, the actual vehicle speed of the preceding vehicle, and the measured inter-vehicle distance, and according to the measured inter-vehicle distance, the display interval between the image of the preceding vehicle and the image of the own vehicle is displayed. To adjust.

[0032]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. Hereinafter, the configuration according to this embodiment will be described with reference to FIG. In FIG. 1, a distance detecting unit (detecting unit) 1, a traveling state detecting unit (detecting unit) 2, a signal processing unit (display control unit) 3, and an alarm notifying unit (alarm unit) 4
Are the same as or similar to those of the configuration described with reference to FIG. 4, and therefore, the same reference numerals are given and their description is omitted. Only different configurations will be described below.

That is, in FIG. 1, reference numeral 5 denotes a display (display means) which is arranged in front of the driver's seat of the vehicle and gives information necessary for driving to the driver. Actual speed Va of the own vehicle supplied via
The calculated vehicle speed Vf and the measured inter-vehicle distance R of the preceding vehicle are displayed, and traffic information from an external fixed radio station (not shown) is displayed.

When the signal 6 indicating the actual speed Vf of the own vehicle, the calculated vehicle speed Va of the preceding vehicle, and the measured inter-vehicle distance R is received from the arithmetic circuit 41 ', the vehicle image data is read from the memory 7, and as shown in FIG. In addition, the front vehicle and the own vehicle are displayed at positions B and C at both lower ends of the display screen A, and the calculated vehicle speed Va of the front vehicle is displayed at a position D above the image of the front vehicle. The actual vehicle speed Vf of the own vehicle is displayed at the position E, and the measured inter-vehicle distance R is displayed at the position F between the display position D of the calculated vehicle speed Va of the preceding vehicle and the display position E of the actual vehicle speed Vf of the own vehicle. It is a display control circuit (display means) for displaying. The display control circuit 6
Changes the distance L between the image of the preceding vehicle and the image of the host vehicle according to the measured inter-vehicle distance. That is, when the measured inter-vehicle distance is reduced, the interval L is reduced.

The operation circuits 41 'and 41
The difference is that the calculation circuit 41 'calculates the calculation vehicle speed Va of the preceding vehicle.
And the actual vehicle speed Vf of the own vehicle is also output to the display control circuit 6.

Next, the operation of the arithmetic circuit 41 'will be described with reference to the flowchart shown in FIG. The difference between this flowchart and the flowchart shown in FIG.
Since steps ST22 to ST22 are added, only different points will be described below, and the same or similar operations will be denoted by the same reference numerals and detailed description thereof will be omitted.

At step ST19, the measured inter-vehicle distance R taken at step ST11 and the actual speed Vf of the own vehicle are set.
And the calculated vehicle speed Va of the preceding vehicle calculated in step ST13 is displayed at the center left position D of the display 5 as shown in FIG. The actual vehicle speed Vf is displayed.
That is, the measured inter-vehicle distance R is set at a position between the display position D of the vehicle speed Va of the preceding vehicle and the display position E of the actual vehicle speed Vf of the own vehicle.
Is displayed. In step ST20, the display control circuit 6
Reads the vehicle image data from the memory 7 and
The front vehicle is displayed at a position B on the lower left side of the vehicle, and the own vehicle is displayed at a position C on the lower right side.

In step ST21, the arithmetic circuit 4
1 'calculates the display interval L of the vehicle image data taken in step ST20 based on the measured inter-vehicle distance R taken in step ST11. Then, in step ST22, the vehicle image data is stored in step S22.
It is displayed at the interval L calculated at T21.

As described above, according to the first embodiment, as shown in FIG.
In addition to displaying and displaying the preceding vehicle and the own vehicle respectively, the vehicle speed Va of the preceding vehicle is displayed at a position D above the display position B of the image of the preceding vehicle, and the position E above the image display position C of the own vehicle is displayed. Since the vehicle speed Vf of the own vehicle is displayed, and the calculated inter-vehicle distance R is displayed at the position F between the display position D of the calculated vehicle speed Va of the preceding vehicle and the display position E of the actual vehicle speed Vf of the own vehicle. Thus, it is possible to easily understand how dangerous the current situation is.

Further, the interval between the image of the preceding vehicle and the image of the own vehicle is indicated by an arrow according to the calculated inter-vehicle distance R, and the length L of the arrow is changed. Is obtained. In the above embodiment, the display control circuit 6
It is also possible to add traffic information etc. as input to
In this case, it goes without saying that the operation is performed by an external operation using a changeover switch (not shown).

[0041]

As described above, according to the present invention, at least the calculated vehicle speed of the preceding vehicle and the measured inter-vehicle distance between the preceding vehicle and the own vehicle are displayed on one display screen in association with each other. The effect is that it is possible to easily grasp how dangerous the current situation is.

Further, according to the present invention, an image of the preceding vehicle and an image of the own vehicle are displayed on the display screen, and the display interval between the image of the preceding vehicle and the image of the own vehicle is adjusted according to the inter-vehicle distance. , There is an effect that the state of the following distance can be intuitively recognized.

Further, according to the present invention, detecting means for detecting the vehicle speed of the own vehicle, the vehicle speed of the preceding vehicle, and the distance between the own vehicle and the preceding vehicle, and display means for displaying at least the vehicle speed and the following distance of the preceding vehicle And display control means for controlling the display means according to the vehicle speed of the preceding vehicle detected by the detecting means and the distance between the host vehicle and the preceding vehicle, so that how dangerous the current situation is There is an effect that can be easily grasped.

Further, according to the present invention, a warning that the own vehicle collides with the preceding vehicle is issued in accordance with the vehicle speed of the own vehicle, the vehicle speed of the preceding vehicle, and the distance between the own vehicle and the preceding vehicle detected by the detecting means. Since it is configured to include an alarm unit that performs a warning, it is possible to easily understand how dangerous the current situation is, and to issue an alarm when there is a possibility of collision.

Further, according to the present invention, a memory for storing vehicle image data is provided, the display control means reads the vehicle image data from the memory, and the display means displays the image of the preceding vehicle and the image of the own vehicle on the display device. Displayed together with the speed of the vehicle, the speed of the preceding vehicle, and the following distance, and according to the following distance,
Since the display interval between the image of the preceding vehicle and the image of the host vehicle is adjusted, there is an effect that the state of the following distance can be intuitively recognized.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a vehicle speed display device according to Embodiment 1 of the present invention.

FIG. 2 is a flowchart illustrating an operation of an arithmetic circuit 41 ′ in FIG. 1;

FIG. 3 is a diagram showing an example of various types of information displayed in the first embodiment of the present invention.

FIG. 4 is a block diagram showing a configuration of a conventional collision prevention device.

5 is a timing chart showing waveforms of various signals in the collision prevention device of FIG.

FIG. 6 is a flowchart illustrating an operation of an arithmetic circuit 41 of the collision prevention device of FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Distance detection part (detection means) 2 Running state detection part (detection means) 3 Signal processing part (display control means) 4 Warning notification part (alarm means) 5 Display (display means) 6 Display control circuit (display control means) 7 memory 41, 41 'arithmetic circuit

Claims (6)

[Claims] 1. A vehicle speed display method, wherein at least an actual vehicle speed of a preceding vehicle and a measured inter-vehicle distance between the preceding vehicle and the own vehicle are simultaneously displayed on one display screen in a corresponding manner. 2. The one display screen displays an actual vehicle speed of a preceding vehicle, a measured inter-vehicle distance between the preceding vehicle and the own vehicle, and an actual vehicle speed of the own vehicle in association with each other. The vehicle speed display method according to claim 1, wherein the distance is displayed at a position between the display of the actual vehicle speed of the preceding vehicle and the display of the actual vehicle speed of the host vehicle. 3. The display screen displays two vehicle images in front of and behind a straight line, and adjusts an interval between two vehicle images arranged in front of and behind the straight line according to the measured inter-vehicle distance. 3. The vehicle speed display method according to claim 2, wherein: 4. A detecting means for detecting the actual vehicle speed of the own vehicle, the actual vehicle speed of the preceding vehicle, and the measured inter-vehicle distance between the own vehicle and the preceding vehicle, and a display for displaying at least the actual vehicle speed of the preceding vehicle and the measured inter-vehicle distance. And a display control means for controlling display contents of the display means according to an actual vehicle speed of the preceding vehicle detected by the detecting means and a measured inter-vehicle distance between the host vehicle and the preceding vehicle. . 5. The host vehicle collides with the front vehicle according to an actual vehicle speed of the host vehicle detected by the detection means, an actual vehicle speed of the front vehicle, and a measured inter-vehicle distance between the host vehicle and the front vehicle. 5. The vehicle speed display device according to claim 4, further comprising alarm means for alarming the fact. 6. A memory for storing vehicle image data, wherein the display control means reads vehicle image data from the memory, and displays the two vehicle images on the display means, the actual speed of the own vehicle, The display according to claim 4, wherein the display is performed together with the actual vehicle speed of the preceding vehicle and the measured inter-vehicle distance, and a display interval between the image of the preceding vehicle and the image of the own vehicle is adjusted according to the measured inter-vehicle distance. 6. The vehicle speed display device according to claim 5.