JP2006335134A - Brake lighting form controlling device, rear-end collision alarming device, inter-vehicle distance controlling device, brake lamp information transmitting system and its method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To transmit the information which the foregoing vehicle has to the following vehicle through a lighting form of a brake lamp by interlocking the information which the foregoing vehicle has with the lighting form of the brake lamp. <P>SOLUTION: A brake lighting form controlling device is equipped with a brake operation sensing means to sense the physical amount whereon the brake operation of the driver is reflected and a brake lamp controlling means to control the lighting form of the brake lamp in accordance with the physical amount sensed by the brake operation sensing means. A tail-end collision alarming device is equipped with an image pickup means to photograph the brake lamp of the foregoing vehicle, a brake operation amount calculating means to calculate the size of the brake operation from the lighting form of the brake lamp, an inter-vehicle distance sensing means to determine the inter-vehicle distance between the forgoing vehicle and the vehicle concerned, a future inter-vehicle distance predicting means to predict the future inter-vehicle distance from the size of the brake operation and the inter-vehicle distance, and an alarm controlling means to control whether an alarm is to be given or not to the driver about a likely collision with the foregoing vehicle on the basis of the future inter-vehicle distance. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a brake lighting mode control device, a rear-end collision warning device, an inter-vehicle distance control device, a brake lamp information transmission system, and a brake lamp information transmission method that transmit information held by a preceding vehicle to a subsequent vehicle via a lighting mode of a brake lamp.

Conventionally, a preceding vehicle braking identification device having a recognition means for recognizing a front image captured by an in-vehicle camera and detecting lighting of a brake lamp in a preceding vehicle, or an alarm when a lighting of a brake lamp is detected. Alternatively, a vehicle control device that performs deceleration control or inter-vehicle distance control by operating a braking mechanism or a throttle mechanism is known (see, for example, Patent Document 1).
JP-A-9-267686

  With the apparatus of Patent Document 1, it is not possible to detect the magnitude of the deceleration of the preceding vehicle, only by detecting whether or not the brake lamp is lit. Therefore, it is difficult to accurately predict the risk of a rear-end collision with the own vehicle due to the deceleration of the preceding vehicle. Accordingly, there may be a situation in which an excessive rear-end warning is issued or the inter-vehicle distance control device frequently performs acceleration / deceleration in response to excessive lighting of the brake lamp of the preceding vehicle.

  The first feature of the present invention is that a brake operation detecting means for detecting a physical quantity reflecting a driver's brake operation, and a brake for controlling a lighting state of a brake lamp in accordance with the physical quantity detected by the brake operation detecting means. The gist of the present invention is a brake lighting mode control device including a lamp control means.

  According to a second aspect of the present invention, there is provided imaging means for imaging a brake lamp of a preceding vehicle whose lighting mode is controlled according to a physical quantity that reflects a driver's braking operation, and the brake operation based on the lighting mode of the brake lamp. A brake operation amount calculation means for calculating the magnitude of the vehicle, an inter-vehicle distance detection means for obtaining an inter-vehicle distance between the preceding vehicle and the host vehicle, and predicting the future inter-vehicle distance from the magnitude of the brake operation and the inter-vehicle distance. The gist of the present invention is a rear-end collision warning device comprising a future inter-vehicle distance prediction means and an alarm control means for controlling whether to warn a driver of a rear-end collision with the preceding vehicle based on the future inter-vehicle distance. To do.

  According to a third aspect of the present invention, there is provided imaging means for imaging a brake lamp of a preceding vehicle whose lighting form is controlled in accordance with a physical quantity that reflects a driver's braking operation, and the brake lamp imaged by the imaging means. Brake operation amount calculating means for calculating the magnitude of the brake operation from the lighting mode, preceding vehicle behavior predicting means for predicting the deceleration behavior of the preceding vehicle from the magnitude of the brake operation, and the preceding vehicle and the host vehicle The gist of the present invention is an inter-vehicle distance control device that includes an inter-vehicle distance detection unit that determines an inter-vehicle distance, and an inter-vehicle distance control unit that controls the inter-vehicle distance based on the inter-vehicle distance and the deceleration behavior determined by the inter-vehicle distance detection unit. To do.

  A fourth feature of the present invention is provided with a brake information transmitting device and a brake information receiving device, the brake information transmitting device including a brake operation detecting means for detecting a physical quantity reflecting a driver's brake operation, and the brake Brake light control means for controlling the lighting state of the brake lamp according to the physical quantity detected by the operation detection means, and the brake information receiving device is an image pickup means for picking up an image of the brake lamp of a preceding vehicle, and the image pickup means. And a preceding vehicle information acquisition means for acquiring information of the preceding vehicle from the lighting state of the brake lamp imaged by the vehicle.

  According to a fifth aspect of the present invention, a physical quantity reflecting a driver's brake operation is detected, a lighting state of a brake lamp is controlled according to the physical quantity, the brake lamp of a preceding vehicle is imaged, and the brake lamp This is a brake lamp information transmission method for acquiring information of the preceding vehicle from the lighting mode.

  According to the present invention, the brake lighting form control device for transmitting information held by the preceding vehicle to the succeeding vehicle through the lighting form of the brake lamp by interlocking the information that the preceding vehicle has with the lighting form of the brake lamp, the rear collision An alarm device, an inter-vehicle control device, a brake lamp information transmission system, and a brake lamp information transmission method can be provided.

  Embodiments of the present invention will be described below with reference to the drawings. In the description of the drawings, the same or similar parts are denoted by the same or similar reference numerals.

(First embodiment)
[Constitution]
As shown in FIG. 1, the brake lighting control apparatus according to the first embodiment of the present invention includes a brake operation detecting means (hydraulic sensor 2) that detects a physical quantity that reflects a driver's brake operation, Brake lamp control means (brake lamp drive circuit 3) for controlling the lighting mode of the brake lamp 24 according to the physical quantity detected by the operation detection means.

  The “physical quantity reflecting the driver's braking operation” is an amount indicating the braking force of the vehicle controlled by the driver. Here, the foot brake pedal 21 that the driver can step on with the foot is connected to the brake 23 via the hydraulic system 22, and the driver increases the foot brake pedal as the stepping angle of the foot brake pedal 21 increases by the driver. As the pedal 21 is depressed, the hydraulic pressure increases, and as a result, the braking force of the vehicle increases. In this case, the depression angle of the foot brake pedal 21 and the hydraulic pressure of the hydraulic system 22 detected by the hydraulic sensor 2 are included in the “physical quantity reflecting the driver's brake operation”. The hydraulic pressure sensor 2 transmits the detected hydraulic pressure to the brake lamp drive circuit 3 as a brake pressure signal SG1.

  The brake lamp drive circuit 3 as the brake lamp control means controls the lighting mode of the brake lamp 24 according to the received brake pressure signal SG1. Specifically, the brake lamp drive circuit 3 generates a modulation drive signal SG2 from the brake pressure signal SG1 and transmits it to the brake lamp 24. The modulation drive signal SG2 is a control signal for modulating the blinking frequency of the brake lamp 24. The brake lamp 24 is lit in a lighting mode according to the modulation drive signal SG2.

  As shown in FIG. 2A, when the depression angle of the foot brake pedal 21 is 0 degree or within the range of the play angle, the brake lamp 24 is turned off, but the depression angle of the foot brake pedal 21 is substantially equal. When it is not 0 degree at a time, the brake lamp 24 is repeatedly turned on and off at the blinking frequency f according to the modulation drive signal SG2, that is, blinks.

  As shown in FIG. 2B, the blinking frequency f increases as the brake pressure, that is, the depression angle of the foot brake pedal 21 (hereinafter simply referred to as “brake pressure”) increases. Preferably it increases linearly.

The blinking frequency f is preferably higher than the maximum frequency (the critical eye fusion frequency frequency) at which the blinking of the direction indicator lamp can be recognized by the human naked eye. More preferably, flicker frequency f varies until half the sampling frequency f _c of the in-vehicle camera 4 of Figure 3 to be described later from the naked eye of the critical fusion frequency frequency _{f e (f c / 2)} .

  With reference to FIG. 3, the rear-end collision alarm device according to the first embodiment of the present invention will be described. The rear-end collision warning device includes an image pickup means (on-vehicle camera 4) for picking up an image of a brake lamp of a preceding vehicle equipped with the brake lighting type control device of FIG. Calculation means (demodulation processing section 5), inter-vehicle distance detection means (inter-vehicle distance detection section 6) for determining the inter-vehicle distance between the preceding vehicle and the host vehicle, and the magnitude of the brake operation and the inter-vehicle distance detection calculated by the demodulation processing section 5 The future inter-vehicle distance prediction means (future inter-vehicle distance prediction calculation unit 7) that predicts the future inter-vehicle distance from the inter-vehicle distance detected by the unit 6, and warns the driver of a collision with a preceding vehicle based on the future inter-vehicle distance Alarm control means (alarm necessity determination processing unit 8) for controlling whether or not to perform, and an alarm unit 25 for warning the driver of the rear-end collision according to the control result of the alarm necessity determination processing unit 8 .

The “imaging means” captures an image necessary for identifying the lighting mode of the brake lamp 24 in FIG. When the blinking frequency f shown in FIGS. 2 (a) and 2 (b) is controlled as the lighting mode, the vehicle-mounted camera 4 as an example of the imaging means has a frame rate (required for identifying the blinking frequency f). comprising a sampling frequency f _c). When the lighting luminance or the lighting luminance change amount is controlled as the lighting mode, the imaging unit has a function capable of identifying the lighting luminance or the lighting luminance change. The in-vehicle camera 4 transfers the captured brake lamp image SG3 to the demodulation processing unit 5.

  The demodulation processing unit 5 calculates the blink frequency f of the brake lamp 24 from the brake lamp photographed image SG3, and calculates the brake operation magnitude (brake pressure) of the preceding vehicle from the blink frequency f. Then, the brake pressure signal SG4 is transmitted to the future inter-vehicle distance prediction calculation unit 7.

  The inter-vehicle distance detection unit 6 transmits the inter-vehicle distance SG5 between the preceding vehicle and the host vehicle to the future inter-vehicle distance prediction calculation unit 7.

  The future inter-vehicle distance prediction calculation unit 7 predicts the deceleration behavior of the preceding vehicle from the brake pressure and the inter-vehicle distance from the preceding vehicle, and predicts the future inter-vehicle distance. For example, the inter-vehicle distance from the preceding vehicle when a certain time (predicted section) has elapsed from the present time is calculated as the “future inter-vehicle distance”. Then, the future inter-vehicle distance SG6 is transmitted to the alarm necessity determination processing unit 8.

  The alarm necessity determination processing unit 8 determines that the alarm is necessary when the future inter-vehicle distance is less than the alarm threshold, and transmits the alarm driving signal SG7 to the alarm unit 25 for driving. If the future inter-vehicle distance is equal to or greater than the alarm threshold, it is determined that there is no need for alarm, and the alarm unit 25 is not driven.

[Operation]
The operation of the brake lighting mode control device of FIG. 1 will be described with reference to FIG.

  (A) First, in step S1, the hydraulic sensor 2 reads a brake pressure (a brake depression amount). In step S2, the brake lamp drive circuit 3 determines whether or not the brake pressure is greater than or equal to a predetermined value. The predetermined value here corresponds to the play amount of the foot brake pedal 21. If it is determined that the brake pressure is greater than or equal to a predetermined value (YES in step S2), the process proceeds to step S3. If it is determined that the brake pressure is less than the predetermined value (NO in step S2), the process proceeds to step S6.

  (B) The brake lamp drive circuit 3 reads the brake pressure in step S3, and determines the blinking frequency (modulation frequency) of the brake lamp 24 in accordance with the brake pressure in step S4. In step S5, a modulation drive signal SG2 is generated and transmitted to the brake lamp 24.

  (C) On the other hand, in step S6, it is determined that the foot brake pedal 21 is not depressed, and the brake lamp 24 is turned off.

  Through the above procedure, as shown in FIG. 7, the lighting mode of the brake lamp of the preceding vehicle 26 is controlled, and the information (brake pressure information) held by the preceding vehicle 26 through the lighting mode of the brake lamp is the following vehicle 27. Sent to.

  With reference to FIG. 5, operations of the in-vehicle camera 4 and the demodulation processing unit 5 in FIG. 3 will be described.

  (1) First, in step S11, the in-vehicle camera 4 mounted on the succeeding vehicle 27 in FIG. 7 captures an image of the preceding vehicle 26. In step S12, the demodulation processing unit 5 extracts a brake lamp part from the image.

  (2) In step S13, the demodulation processing unit 5 determines whether or not to detect a lighting state. If the lighting state is detected (YES in step S13), the process proceeds to step S14. If the lighting state is not detected (NO in step S13), the process proceeds to step S17.

  (3) The demodulation processing unit 5 calculates the blinking time interval from the time when the previous brake lamp lighting was detected in step S14, and records and updates the current time as the time when the brake lamp lighting was detected in step S15. . In step S <b> 16, the demodulation processing unit 5 calculates the brake pressure of the preceding vehicle from the blinking time interval, and outputs the brake pressure signal SG <b> 4 to the future inter-vehicle distance prediction calculation unit 7.

  (4) On the other hand, in step S17, it is determined whether or not the non-lighting state continues for a predetermined number of frames or more. Here, the “predetermined number of frames” is calculated from the frame rate of the in-vehicle camera 4. If the predetermined number of frames have been continued (YES in step S17), it is determined that the brake lamp is turned off, and the process proceeds to step S18. If it has not continued for a predetermined number of frames (NO in step S17), it means that the brake lamp is lit again in the predetermined frame. Therefore, it is determined that the brake lamp is blinking, and the process proceeds to step S20. move on.

  (5) The demodulation processing unit 5 deletes the lighting detection time in step S18, determines that the brake pressure is 0 in step S19, and transmits a brake pressure signal SG4 to that effect to the future inter-vehicle distance prediction calculation unit 7. To do. On the other hand, in step S20, the brake pressure signal SG4 is transmitted to the future inter-vehicle distance prediction calculation unit 7 while maintaining the previously calculated brake pressure value.

  Through the above procedure, as shown in FIG. 7, the succeeding vehicle 27 can receive the information (brake pressure information) of the preceding vehicle 26 transmitted via the brake lamp lighting mode of the preceding vehicle 26. .

  With reference to FIG. 6, operations of the inter-vehicle distance detection unit 6, the future inter-vehicle distance prediction calculation unit 7, and the alarm necessity determination processing unit 8 of FIG. 3 will be described.

  (I) First, in step S31, the inter-vehicle distance detection unit 6 obtains the inter-vehicle distance between the preceding vehicle 26 and the host vehicle (following vehicle 27). In step S32, the future inter-vehicle distance prediction calculation unit 7 calculates the relative speed with the preceding vehicle from the rate of change of the inter-vehicle distance.

  (II) In step S33, the future inter-vehicle distance prediction calculation unit 7 calculates a predicted value of deceleration of the preceding vehicle from the brake pressure signal SG4. For example, as shown in FIG. 8A, the deceleration of the preceding vehicle is predicted, and the speed change of the preceding vehicle within the prediction section is calculated from the current time.

  (III) In step S34, the future inter-vehicle distance prediction calculation unit 7 predicts the future inter-vehicle distance from the preceding vehicle from the speed change of the preceding vehicle. For example, as shown in FIG. 8B, the change in the inter-vehicle distance within the prediction section is calculated from the current time.

  (IV) In step S35, the future inter-vehicle distance prediction calculation unit 7 calculates the inter-vehicle distance (future inter-vehicle distance) when the prediction section has elapsed from the current time, and the future inter-vehicle distance is set to a predetermined threshold (alarm threshold). Judge whether it is below or not. As shown in FIG. 8 (b), when the value is below the alarm threshold value (YES in step S35), the alarm necessity determination processing unit 8 determines that there is an alarm necessity, generates the alarm drive signal SG7, and outputs it. To do. If it is equal to or greater than the alarm threshold value (NO in step S35), the alarm necessity determination processing unit 8 determines that there is no alarm necessity, and ends the process as it is.

  Through the above procedure, the presence or absence of an alarm can be controlled based on the information (brake pressure information) of the preceding vehicle 26 received by the following vehicle 27.

(Modification)
In the brake lighting mode control device of FIG. 1, the brake lamp drive circuit 3 may perform different controls on two or more brake lamps 24. In this case, in the rear-end collision alarm device of FIG. 3, the demodulation processing unit 5 identifies lighting modes of the two brake lamps. Specifically, as shown in FIG. 9, the brake lamp 24 of the preceding vehicle is divided into two zones, a first zone 24a and a second zone 24b, with respect to the first and second zones 24a, 24b. Thus, a different blinking frequency f may be set. For example, in the first zone 24a, the speed of wherever rows vehicle using a first flicker frequency f ₁ transmitted to the following vehicle, the second zone 24b, by using the second flicker frequency f ₂ prior The brake pressure of the vehicle can be transmitted to the following vehicle. As shown in FIGS. 10 (a) and 10 (b), by giving different flashing frequency characteristics for the speed of the preceding vehicle and the brake pressure of the preceding vehicle, both can be controlled independently. Here, the case where there are two brake lamps has been described, but three or more brake lamps may be used. Here, the “first vehicle” indicates a vehicle that travels in front of the preceding vehicle. Of course, the speed of the preceding vehicle may be used instead of the speed of the preceding vehicle.

  With reference to FIG. 11, the structure of the brake lighting type control apparatus in the case of two brake lamps will be described. The foot brake pedal 21, hydraulic system 22, and brake 23 are the same as in FIG. In FIG. 11, a pedal depression angle sensor 34 that detects the depression angle of the foot brake pedal 21 is used as another example of the brake operation detection unit in place of the hydraulic sensor 2 of FIG. 1. The brake lamp drive circuit 3 in FIG. 1 corresponds to the brake lamp drive circuit 3a in FIG. 11, and the brake lamp 24 in FIG. 1 corresponds to the brake lamp 24a in FIG.

  The own vehicle speed sensor 31 detects the speed of the own vehicle (preceding vehicle). The inter-vehicle distance radar 32 obtains the inter-vehicle distance between the vehicle (first vehicle) and the own vehicle (preceding vehicle) traveling in front of the own vehicle. The preceding vehicle speed calculation unit 33 calculates the speed of the preceding vehicle from the speed of the host vehicle (preceding vehicle) and the inter-vehicle distance. The brake lamp drive circuit 3b calculates the blinking frequency of the brake lamp 24b according to the speed of the preceding vehicle, and drives the brake lamp 24b.

  The depression angle of the foot brake pedal 21 is detected by a pedal depression angle sensor 34. The on / off information of the foot brake pedal 21 is transmitted to the brake lamp driving circuit 3b, and the information on the depression angle of the foot brake pedal 21 is transmitted to the brake lamp driving circuit 3a.

[effect]
As described above, the brake lighting control device according to the first embodiment of the present invention and the modification thereof includes the brake operation detection means for detecting the physical quantity reflecting the driver's brake operation, and the brake operation detection. Brake lamp control means for controlling the lighting mode of the brake lamp 24 in accordance with the physical quantity detected by the means.

  According to this, since the driver's brake operation and the lighting mode (flashing frequency) of the brake lamp 24 can be linked, it is possible to inform the subsequent vehicle how much the vehicle decelerates.

  The brake lamp control means modulates the blinking frequency of the brake lamp 24 in accordance with a physical quantity that reflects the driver's brake operation. According to this, it is possible to notify the subsequent vehicle how much the vehicle decelerates through the blinking frequency of the brake lamp 24.

  The brake lamp control means performs different control on the two or more brake lamps 24. According to this, two or more pieces of information can be simultaneously transmitted to the following vehicle.

  The brake operation detection means detects the brake pressure or the depression angle of the brake pedal as a physical quantity. That is, the hydraulic pressure sensor 2 or the pedal depression angle sensor 34 is used as a brake operation detection unit. As a result, the brake pressure, the pedal depression angle, and the lighting state of the brake lamp 24 can be linked.

  The blinking frequency of the brake lamp is higher than the critical fusion frequency frequency of the naked eye. According to this, since the occupant of the following vehicle cannot recognize the flashing of the brake lamp, the information of the preceding vehicle can be transmitted without confusing the occupant of the following vehicle.

  The rear-end collision warning device according to the first embodiment of the present invention and its modification includes an imaging unit that images a brake lamp of a preceding vehicle whose lighting mode is controlled according to a physical quantity that reflects a driver's brake operation. A brake operation amount calculation means for calculating the magnitude of the brake operation from the lighting state of the brake lamp, an inter-vehicle distance detection means for obtaining an inter-vehicle distance between the preceding vehicle and the host vehicle, the magnitude of the brake operation and the A future inter-vehicle distance predicting means for predicting a future inter-vehicle distance from an inter-vehicle distance, and an alarm control means for controlling whether or not to warn a driver of a collision with the preceding vehicle based on the future inter-vehicle distance; Is provided.

  According to this, not only the lighting of the brake lamp 24 but also the brake operation information put on the lighting form can be read and the deceleration behavior of the preceding vehicle can be predicted with high accuracy, so that only a highly necessary alarm is issued. Excessive reaction can be suppressed.

  The brake operation amount calculation means calculates the magnitude of the brake operation from the blinking frequency of the brake lamp 24. Thereby, it is possible to predict how much the preceding vehicle decelerates via the blinking frequency of the brake lamp 24.

  The brake operation amount calculation means identifies lighting modes of two or more brake lamps 24a and 24b. According to this, two or more pieces of information can be simultaneously received from the preceding vehicle.

  The blinking frequency of the brake lamp 24 is equal to or higher than the critical fusion frequency frequency of the naked eye. According to this, since the occupant of the following vehicle cannot recognize the flashing of the brake lamp, the information of the preceding vehicle can be received without confusing the occupant of the following vehicle.

(Second Embodiment)
[Constitution]
In the second embodiment, from a preceding vehicle equipped with a brake lighting form control device including brake lamp drive circuits 3a and 3b for performing different control on the two brake lamps 24 shown in FIGS. A description will be given of an inter-vehicle control device that receives information held by a preceding vehicle and controls the inter-vehicle distance between the host vehicle (following vehicle) and the preceding vehicle.

  With reference to FIG. 12, the configuration of the inter-vehicle control apparatus according to the second embodiment of the present invention will be described. The inter-vehicle control device includes an imaging unit (on-vehicle camera 4) that images a brake lamp of a preceding vehicle whose lighting form is controlled according to a physical quantity that reflects a driver's brake operation, and a brake lamp imaged by the on-vehicle camera 4 Brake operation amount calculation means (demodulation processing unit 5) for calculating the magnitude of the brake operation of the preceding vehicle and the speed of the preceding vehicle from the lighting mode, and predicting the deceleration behavior of the preceding vehicle from the magnitude of the brake operation and the speed of the preceding vehicle Preceding vehicle behavior prediction means (preceding vehicle behavior prediction calculation unit 9), inter-vehicle distance detection means (inter-vehicle distance detection unit 6) for determining the inter-vehicle distance between the preceding vehicle and the host vehicle, and the inter-vehicle distance obtained by the inter-vehicle distance detection unit 6 An inter-vehicle distance control means for controlling the inter-vehicle distance based on the distance and the deceleration behavior. The inter-vehicle distance control means includes an inter-vehicle distance control calculation unit 10 that calculates an acceleration / deceleration required for the inter-vehicle control, and a braking / driving force control unit 35 that controls the braking / driving force of the vehicle based on the acceleration / deceleration calculation result.

  The in-vehicle camera 4, the demodulation processing unit 5, and the inter-vehicle distance detection unit 6 as imaging means are the same as those in FIG.

  The preceding vehicle behavior prediction calculation unit 9 predicts the deceleration behavior of the preceding vehicle from the magnitude of the brake operation and the inter-vehicle distance from the preceding vehicle. Then, the predicted state quantity SG9 of the preceding vehicle is transmitted to the inter-vehicle distance control calculation unit 10.

  The inter-vehicle distance control calculation unit 10 calculates the acceleration / deceleration from the predicted state quantity SG9 of the preceding vehicle, and transmits the braking / driving force target value SG10 to the braking / driving force control unit 35.

  The braking / driving force control unit 35 controls the braking / driving force of the vehicle according to the braking / driving force target value SG10.

  With reference to FIG. 13A and FIG. 13B, a method in which the preceding vehicle behavior prediction calculation unit 9 predicts the deceleration behavior of the preceding vehicle from the magnitude of the brake operation of the preceding vehicle and the speed of the preceding vehicle will be described. .

  In FIG. 13A, a dotted line PF1 indicates a change in speed of the preceding vehicle when the preceding vehicle decelerates at a deceleration predicted from the information on the brake depression angle of the preceding vehicle obtained from the brake lamp 24a in FIG. . The preceding vehicle behavior prediction calculation unit 9 corrects the dotted line PF1 in consideration of not only the brake depression angle of the preceding vehicle but also the speed information of the preceding vehicle obtained from the brake lamp 24b in FIG. And Considering the speed information of the preceding vehicle as well, it is possible to avoid that the speed of the preceding vehicle is lower than the speed of the preceding vehicle in the prediction section, and it is possible to predict the preceding vehicle closer to reality.

  As shown in FIG. 13 (b), the preceding vehicle behavior prediction calculating unit 9 predicts and calculates the inter-vehicle distance between the host vehicle (following vehicle) and the preceding vehicle from the solid line PF2, and the inter-vehicle distance control calculating unit 10 The inter-vehicle distance is controlled based on the result.

[Operation]
With reference to FIG. 14, the operation of the brake lighting mode control apparatus in the second embodiment will be described.

  (A) First, in step S41, the pedal depression angle sensor 34 reads the brake depression amount. In step S42, the brake lamp drive circuit 3a determines whether or not the brake depression amount is a predetermined value or more. The predetermined value here corresponds to the play amount of the foot brake pedal 21. If it is determined that the amount of brake depression is greater than or equal to a predetermined value (YES in step S42), the process proceeds to step S43, and if it is determined that the amount of brake depression is less than the predetermined value (NO in step S42), the process proceeds to step S47.

  (B) In step S43, the preceding vehicle speed calculation unit 33 calculates the inter-vehicle distance between the preceding vehicle and the host vehicle (preceding vehicle). In step S44, the preceding vehicle speed calculation unit 33 calculates the speed of the preceding vehicle. To do.

  (C) In step S45, the brake lamp drive circuits 3a and 3b determine the modulation frequencies of the first and second zones 24a and 24b, respectively. In step S46, the brake lamp drive circuits 3a and 3b generate drive signals for the brake lamps 24a and 24b according to the modulation frequency.

  (D) On the other hand, in step S47, it is determined that the foot brake pedal 21 is not depressed, and the brake lamps 24a and 24b are turned off.

  Through the above procedure, the lighting form of the brake lamps 24a, 24b of the preceding vehicle is controlled, and information that the preceding vehicle has via the lighting form of the brake lamps 24a, 24b (information on the brake pressure of the preceding vehicle and the speed of the preceding vehicle) ) Is transmitted to the following vehicle 27.

  With reference to FIG. 15, operations of the in-vehicle camera 4 and the demodulation processing unit 5 in FIG. 12 will be described.

  (1) First, the vehicle-mounted camera 4 mounted on the succeeding vehicle in step S51 captures an image of the preceding vehicle. In step S52, the demodulation processing unit 5 extracts the brake lamp 24a (24b) portion from the image.

  (2) In step S53, the demodulation processing unit 5 determines whether or not to detect a lighting state. If the lighting state is detected (YES in step S53), the process proceeds to step S54. If the lighting state is not detected (NO in step S53), the process proceeds to step S57.

  (3) The demodulation processing unit 5 calculates the blinking time interval from the time when the previous lighting of the brake lamp 24a (24b) was detected in step S54, and the current time is turned on in step S55. Record and update as detected time. In step S56, the demodulation processing unit 5 calculates the depression angle of the brake pedal of the preceding vehicle (the speed of the preceding vehicle) from the blinking time interval, and sends the brake pressure signal SG4 and the preceding vehicle speed signal to the preceding vehicle behavior prediction calculating unit 9. SG8 is output.

  (4) On the other hand, in step S57, it is determined whether or not the non-lighting state continues for a predetermined number of frames or more. Here, the “predetermined number of frames” is calculated from the frame rate of the in-vehicle camera 4. If the predetermined number of frames have been continued (YES in step S57), it is determined that the brake lamp has been turned off, and the process proceeds to step S58. If the predetermined number of frames has not been continued (NO in step S57), it means that the brake lamp is lit again in the predetermined frame, so it is determined that the brake lamp is blinking, and the process proceeds to step S60. move on.

  (5) The demodulation processing unit 5 deletes the lighting detection time in step S58, determines in step S59 that the brake pressure is 0 (no information on the preceding vehicle), and determines that the brake pressure signal SG4 and the preceding vehicle speed. The signal SG8 is transmitted to the preceding vehicle behavior prediction calculation unit 9. On the other hand, in step S60, the brake pressure signal SG4 and the preceding vehicle speed signal SG8 are transmitted to the preceding vehicle behavior prediction calculation unit 9 while maintaining the brake pressure value (predecessor vehicle information) calculated last time.

  Through the above procedure, the succeeding vehicle can receive the information (the brake pressure and the preceding vehicle speed information) of the preceding vehicle 26 transmitted via the lighting form of the brake lamp of the preceding vehicle.

  With reference to FIG. 16, operations of the inter-vehicle distance detection unit 6, the preceding vehicle behavior prediction calculation unit 9, and the inter-vehicle distance control calculation unit 10 of FIG. 12 will be described.

  (I) First, in step S71, the inter-vehicle distance detection unit 6 obtains the inter-vehicle distance between the preceding vehicle and the host vehicle (following vehicle). In step S72, the preceding vehicle behavior prediction calculation unit 9 calculates the relative speed with the preceding vehicle from the rate of change of the inter-vehicle distance.

  (II) In step S73, the preceding vehicle behavior prediction calculation unit 9 calculates a predicted value of the deceleration behavior of the preceding vehicle from the brake pressure signal SG4 and the preceding vehicle speed signal SG8. For example, as shown in FIG. 13A, the deceleration of the preceding vehicle is predicted, and the speed change of the preceding vehicle within the prediction section is calculated from the current time.

  (III) In step S74, the preceding vehicle behavior prediction calculation unit 9 predicts the future inter-vehicle distance from the preceding vehicle and the future speed of the preceding vehicle from the speed change of the preceding vehicle. For example, as shown in FIG. 13B, the change in the inter-vehicle distance within the predicted section is calculated from the current time.

  (IV) In step S75, the inter-vehicle distance control calculation unit 10 calculates a target value for inter-vehicle distance control from the state of the preceding vehicle when the predicted section has elapsed from the current time. In step S <b> 76, the inter-vehicle distance control calculation unit 10 calculates a command value for the actuator for controlling the vehicle braking / driving force, and transmits the command value to the braking / driving force control unit 35.

  Through the above procedure, the braking / driving force of the vehicle can be controlled based on the information (brake pressure and speed information of the preceding vehicle) that the preceding vehicle has received by the following vehicle.

[effect]
As described above, the inter-vehicle control apparatus according to the second embodiment of the present invention images the brake lamp of the preceding vehicle whose lighting mode is controlled according to the physical quantity reflecting the driver's brake operation. From means (vehicle-mounted camera) 4, brake operation amount calculation means (demodulation processing unit) 5 that calculates the magnitude of the brake operation from the lighting state of the brake lamp imaged by the imaging means, and the magnitude of the brake operation Preceding vehicle behavior predicting means (previous vehicle behavior prediction calculating unit) 9 for predicting the deceleration behavior of the preceding vehicle, inter-vehicle distance detecting means (inter-vehicle distance detecting unit 6) for determining an inter-vehicle distance between the preceding vehicle and the host vehicle, Vehicle distance control means (10, 35) for controlling the vehicle distance based on the vehicle distance and the deceleration behavior obtained by the vehicle distance detection means.

  According to this, not only the lighting of the brake lamp 24 but also the brake operation information put on the lighting mode can be read and the deceleration behavior of the preceding vehicle can be accurately predicted, so that the inter-vehicle distance control is performed with high accuracy. Thus, it is possible to suppress an excessive reaction to the behavior of the preceding vehicle.

  The brake operation amount calculation means calculates the magnitude of the brake operation from the blinking frequency of the brake lamp 24a. Thereby, it can be predicted how much the preceding vehicle decelerates via the blinking frequency of the brake lamp 24a.

  The brake operation amount calculation means identifies lighting modes of two or more brake lamps 24a and 24b. According to this, two or more pieces of information can be simultaneously received from the preceding vehicle.

  The blinking frequency of the brake lamps 24a and 24b is equal to or higher than the critical fusion frequency frequency of the naked eye. According to this, since the occupant of the following vehicle cannot recognize the flashing of the brake lamp, the information of the preceding vehicle can be received without confusing the occupant of the following vehicle.

(Third embodiment)
In the brake lighting type control device, the brake lamp control means (brake lamp driving circuit 3) for controlling the lighting form of the brake lamp 24 according to the physical quantity detected by the brake operation detecting means is configured to control the brake lamp according to the physical quantity. The lighting brightness may be changed. That is, the lighting brightness may be controlled as a lighting mode of the brake lamp 24. In this case, the brake operation amount calculation means (the demodulation processing unit 5) in the rear-end collision warning device and the inter-vehicle distance control device calculates the magnitude of the brake operation or the speed of the preceding vehicle from the lighting brightness of the brake lamp 24.

  For example, as shown in FIG. 17, the lighting brightness is changed according to the brake depression angle. The brake lamp 24 is lit only when a predetermined play angle is provided for the brake depression angle and a depression angle greater than that is detected, and the lighting brightness is increased linearly according to the depression angle.

  As described above, the brake lamp control means of the brake lighting form control device changes the lighting brightness of the brake lamp according to the physical quantity detected by the brake operation detecting means. According to this, it is possible to notify the subsequent vehicle how much the vehicle decelerates through the lighting brightness of the brake lamp 24.

  The brake operation amount calculation means of the rear-end collision warning device and the inter-vehicle distance control device calculates the magnitude of the brake operation from the lighting brightness of the brake lamp 24. Thereby, it is possible to predict how much the preceding vehicle decelerates through the lighting brightness of the brake lamp 24.

(Fourth embodiment)
Further, in the brake lighting mode control device, the brake lamp control means (brake lamp drive circuit 3) for controlling the lighting mode of the brake lamp 24 according to the physical quantity detected by the brake operation detecting means, The lighting luminance change amount may be changed. That is, the lighting luminance change amount may be controlled as the lighting mode of the brake lamp 24 instead of the lighting luminance. In this case, the brake operation amount calculation means (demodulation processing unit 5) in the rear-end collision warning device and the inter-vehicle distance control device calculates the magnitude of the brake operation from the lighting luminance change amount of the brake lamp 24.

  For example, as shown in FIG. 18A, the amount of change in lighting luminance is changed according to the brake depression angle. A predetermined play angle is provided for the brake depression angle, and the luminance of the brake lamp 24 is gradually increased according to the brake depression angle only when a depression angle greater than that is detected. In FIG. 18A, when the brake depression angle is large (in the case of sudden braking), the luminance change is suddenly increased, and when the brake depression angle is small (in the case of slow braking), the luminance change is gradually increased. The relationship between the lighting brightness change amount and the depression angle of the brake pedal is as shown in FIG.

  As described above, the brake lamp control means of the brake lighting mode control device changes the lighting intensity change amount of the brake lamp according to the physical quantity detected by the brake operation detecting means. According to this, it is possible to notify the subsequent vehicle how much the vehicle decelerates through the amount of change in the lighting brightness of the brake lamp 24.

  The brake operation amount calculation means of the rear-end collision warning device and the inter-vehicle control device calculates the magnitude of the brake operation from the amount of change in the lighting brightness of the brake lamp 24. Thereby, it can be predicted how much the preceding vehicle decelerates through the amount of change in the lighting brightness of the brake lamp 24.

(Fifth embodiment)
In the fifth embodiment, the brake lighting control device (FIGS. 1 and 11) shown in the first and second embodiments and the rear-end collision warning device (FIG. 3) shown in the first embodiment. Or the system (brake lamp information transmission system) which combined the inter-vehicle distance control apparatus (FIG. 12) shown in 2nd Embodiment is demonstrated.

  The brake lamp information transmission system corresponds to a device (brake information transmission device) corresponding to the brake lighting type control device shown in FIG. 1 or FIG. 11, and a rear-end collision warning device or an inter-vehicle distance control device shown in FIG. 3 or FIG. Device (brake information receiving device).

  The brake information transmitting device includes a brake operation detection unit that detects a physical quantity that reflects a driver's brake operation, and a brake lamp control unit that controls a lighting state of the brake lamp according to the physical quantity detected by the brake operation detection unit. Have.

  The brake information receiving device includes an imaging unit that images a brake lamp of a preceding vehicle, and a preceding vehicle information acquisition unit that acquires information of the preceding vehicle from a lighting state of the brake lamp captured by the imaging unit.

  The “information that the preceding vehicle has” includes information on the magnitude of the brake operation of the preceding vehicle and the vehicle in front of the preceding vehicle (previous vehicle). The “information about the predecessor vehicle” includes, for example, the distance between the predecessor vehicle and the preceding vehicle, the speed of the predecessor vehicle, the acceleration / deceleration, and the like.

  As described above, since the information that the preceding vehicle has and the lighting form of the brake lamp 24 of the preceding vehicle can be linked, the information that the preceding vehicle has can be transmitted from the preceding vehicle to the succeeding vehicle.

(Other embodiments)
As described above, the present invention has been described according to the first to fifth embodiments. However, it should not be understood that the description and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  For example, in the above embodiment, the case where the hydraulic sensor 2 or the pedal depression angle sensor 34 is used as the brake operation detection unit has been described. However, the present invention is not limited to this, and the deceleration of the vehicle speed may be detected using the vehicle speed detection means as the physical quantity reflecting the brake operation amount, and the deceleration may be used as the physical quantity. In this case, the physical quantity can be obtained by calculating the speed information obtained from the existing speed sensor without using the hydraulic pressure sensor 2, the pedal depression angle sensor 34, or the like.

  That is, it should be understood that the present invention includes various embodiments not described herein. Therefore, the present invention is limited only by the invention specifying matters according to the scope of claims reasonable from this disclosure.

It is a block diagram which shows the structure of the brake lighting form control apparatus concerning the 1st Embodiment of this invention. FIG. 2A is a graph showing the lighting pattern of the brake lamp, and FIG. 2B is a graph showing the relationship between the flashing frequency and the brake pressure. It is a block diagram which shows the structure of the rear-end collision alarm device concerning the 1st Embodiment of this invention. It is a flowchart which shows operation | movement of the brake lighting form control apparatus of FIG. It is a flowchart which shows operation | movement of the vehicle-mounted camera of FIG. 3, and a demodulation process part. It is a flowchart which shows operation | movement of the inter-vehicle distance detection part of FIG. It is a schematic diagram which shows a mode that the information (brake pressure) which a preceding vehicle has via the lighting form of the brake lamp of a preceding vehicle is transmitted / received with respect to a following vehicle. FIG. 8A is a graph showing the predicted value of the time change of the speed of the preceding vehicle, and FIG. 8B is a graph showing the predicted value of the time change of the inter-vehicle distance from the preceding vehicle. FIG. 9A is a plan view showing a brake lamp part of the preceding vehicle, and FIG. 9B is an enlarged view of the brake lamp part. FIG. 10A is a graph showing the relationship between the speed of the preceding vehicle and the flashing frequency, and FIG. 10B is a graph showing the relationship between the brake pressure of the preceding vehicle and the flashing frequency. It is a block diagram which shows the structure of the brake lighting form control apparatus concerning the modification of 1st Embodiment. It is a block diagram which shows the structure of the headway control apparatus concerning the 2nd Embodiment of this invention. It is a graph explaining how the preceding vehicle behavior prediction calculation unit predicts the deceleration behavior of the preceding vehicle from the magnitude of the brake operation of the preceding vehicle and the speed of the preceding vehicle, and (a) is the speed of the preceding vehicle in the prediction section. (B) shows the change in the inter-vehicle distance within the predicted section. It is a flowchart which shows operation | movement of the brake lighting form control apparatus in 2nd Embodiment. It is a flowchart which shows operation | movement of the vehicle-mounted camera of FIG. 12, and a demodulation process part. 13 is a flowchart illustrating operations of an inter-vehicle distance detection unit, a preceding vehicle behavior prediction calculation unit, and an inter-vehicle distance control calculation unit in FIG. 12. It is a graph explaining the brake lamp drive circuit which changes lighting brightness according to a brake depression angle. FIG. 18A is a graph for explaining a brake lamp driving circuit that changes the lighting luminance change amount according to the brake depression angle, and FIG. 18B is a graph showing the relationship between the brake depression angle and the lighting luminance change amount. It is.

Explanation of symbols

2 ... Hydraulic sensor (brake operation detection means)
3, 3a, 3b ... Brake lamp drive circuit (brake lamp control means)
4 ... In-vehicle camera (imaging means)
5 ... Demodulation processor (brake operation amount calculation means)
6 ... Inter-vehicle distance detection unit (inter-vehicle distance detection means)
7. Future inter-vehicle distance prediction calculation unit (future inter-vehicle distance prediction means)
8 ... Alarm necessity judgment processing part (alarm control means)
9 ... Preceding vehicle behavior prediction calculation unit (preceding vehicle behavior prediction means)
10: Inter-vehicle distance control calculation unit (inter-vehicle distance control means)
21 ... Foot brake pedal 22 ... Hydraulic system 23 ... Brake 24 ... Brake lamp 24a ... First zone (brake lamp)
24b ... 2nd zone (brake lamp)
25 ... alarm unit 26 ... preceding vehicle 27 ... following vehicle 28 ... LED
31 ... Own vehicle speed sensor 32 ... Inter-vehicle distance radar 33 ... Previous vehicle speed calculation unit 34 ... Pedal depression angle sensor 35 ... Braking / driving force control unit fc ... Sampling frequency fe ... Critical fusion frequency frequency f ... Flashing frequency

Claims (18)

Brake operation detection means for detecting a physical quantity that reflects the driver's brake operation;
And a brake lamp control unit that controls a lighting mode of the brake lamp according to the physical quantity detected by the brake operation detecting unit.   2. The brake lighting control apparatus according to claim 1, wherein the brake lamp control means modulates the blinking frequency of the brake lamp according to the physical quantity.   2. The brake lighting control device according to claim 1, wherein the brake lamp control means changes a lighting luminance or a lighting luminance change amount of the brake lamp in accordance with the physical quantity.   The brake lighting control device according to any one of claims 1 to 3, wherein the brake lamp control means performs different control on the two or more brake lamps.   The brake lighting form control device according to any one of claims 1 to 4, wherein the brake operation detecting means detects a brake pressure or a depression angle of a brake pedal as the physical quantity.   The brake lighting mode control device according to claim 2, wherein the flashing frequency of the brake lamp is equal to or higher than a critical fusion frequency frequency of the naked eye. An imaging means for imaging a brake lamp of a preceding vehicle whose lighting mode is controlled according to a physical quantity that reflects a driver's brake operation;
Brake operation amount calculation means for calculating the magnitude of the brake operation from the lighting state of the brake lamp,
An inter-vehicle distance detecting means for obtaining an inter-vehicle distance between the preceding vehicle and the host vehicle;
A future inter-vehicle distance prediction means for predicting a future inter-vehicle distance from the magnitude of the brake operation and the inter-vehicle distance;
A rear-end collision warning device comprising: alarm control means for controlling whether or not a driver is warned of a rear-end collision with the preceding vehicle based on the future inter-vehicle distance.   The rear-end collision warning device according to claim 7, wherein the brake operation amount calculation means calculates the magnitude of the brake operation from the blinking frequency of the brake lamp.   8. The rear-end collision warning device according to claim 7, wherein the brake operation amount calculation means calculates the magnitude of the brake operation from the lighting luminance of the brake lamp or the amount of change in lighting luminance.   The rear-end collision warning device according to any one of claims 7 to 9, wherein the brake operation amount calculation means identifies two or more brake lamp lighting modes.   The rear-end collision warning device according to claim 8, wherein the flashing frequency of the brake lamp is equal to or higher than a critical fusion frequency frequency of the naked eye. An imaging means for imaging a brake lamp of a preceding vehicle whose lighting mode is controlled according to a physical quantity that reflects a driver's brake operation;
Brake operation amount calculation means for calculating the magnitude of the brake operation from the lighting form of the brake lamp imaged by the imaging means;
Preceding vehicle behavior predicting means for predicting deceleration behavior of the preceding vehicle from the magnitude of the brake operation;
An inter-vehicle distance detecting means for obtaining an inter-vehicle distance between the preceding vehicle and the host vehicle;
An inter-vehicle distance control unit comprising: an inter-vehicle distance control unit configured to control the inter-vehicle distance based on the inter-vehicle distance and the deceleration behavior obtained by the inter-vehicle distance detection unit.   13. The inter-vehicle distance control device according to claim 12, wherein the brake operation amount calculation means calculates the magnitude of the brake operation from the blinking frequency of the brake lamp.   13. The inter-vehicle distance control device according to claim 12, wherein the brake operation amount calculation means calculates the magnitude of the brake operation from the lighting luminance of the brake lamp or the lighting luminance change amount.   The inter-vehicle distance control device according to any one of claims 12 to 14, wherein the brake operation amount calculation means identifies two or more types of lighting of the brake lamps.   The inter-vehicle control device according to claim 13, wherein the flashing frequency of the brake lamp is equal to or higher than a critical fusion frequency frequency of the naked eye. Brake operation detection means for detecting a physical quantity that reflects the driver's brake operation;
A brake information transmitting device comprising: a brake lamp control means for controlling a lighting state of a brake lamp according to the physical quantity detected by the brake operation detecting means;
Imaging means for imaging the brake lamp of the preceding vehicle;
A brake information receiving system comprising: a preceding vehicle information acquiring unit that acquires information held by the preceding vehicle from a lighting state of the brake lamp imaged by the imaging unit. Detect physical quantities that reflect the driver's braking operation,
Control the lighting mode of the brake lamp according to the physical quantity,
Image the brake lamp of the preceding vehicle,
The information which the preceding vehicle has is acquired from the lighting form of the brake lamp. A brake lamp information transmission method characterized by things.

Images