JP4865006B2 - Vehicle driving support device - Google Patents

Description

  The present invention relates to a vehicle driving support apparatus having an automatic braking control function for automatically interposing a brake appropriately according to a driving environment outside a vehicle.

  In recent years, on-board radar means such as millimeter wave radar and infrared laser radar, imaging means such as stereo cameras and monocular cameras, or combination of these radar means and imaging means recognizes information outside the vehicle and recognizes outside the vehicle. Various proposals have been made for driving support devices that perform various types of vehicle control based on information. As one of the functions of such a driving support device, a cruise control with an inter-vehicle distance control (ACC;) that selectively performs a follow-up running control and a constant speed running control according to the capture state of a preceding vehicle ahead of the host vehicle. Adaptive Cruise Control) function is widely used.

  When this ACC function is executed, for example, in the constant speed running control, the driving support device sets the set vehicle speed set by the driver or the like as the target vehicle speed, and operates the throttle actuator provided in the electronically controlled throttle device. Then, the throttle valve is opened and closed to control the vehicle speed at the target vehicle speed. In the follow-up running control, the host vehicle speed is controlled by opening and closing the throttle valve so as to maintain the target inter-vehicle distance set based on the vehicle speed of the preceding vehicle or the host vehicle. At that time, for example, as a result of the preceding vehicle decelerating by operating the brake, the inter-vehicle distance between the host vehicle and the preceding vehicle becomes shorter than the target inter-vehicle distance, and the throttle valve is fully closed to decelerate, When the inter-vehicle distance cannot be returned to the target inter-vehicle distance, the host vehicle is decelerated by performing automatic braking control by the brake device.

  Incidentally, the lighting of the brake lamp is generally performed by a brake lamp switch mechanically interlocked with the brake pedal. Therefore, during the automatic braking control by the driving support device as described above, even if deceleration by the brake device is performed, the brake lamp is not turned on, and it is difficult to call attention to the deceleration of the own vehicle to the following vehicle or the like. It becomes. In response to this, for example, in Patent Document 1, a brake start request signal (or a brake release request signal) is transmitted from the inter-vehicle control ECU to the brake control ECU based on the comparison result between the inter-vehicle distance detected by the inter-vehicle distance sensor and the target inter-vehicle distance. Signal), and pressurizing control (or stopping pressurization control) of the brake means through the brake control ECU and turning on (or turning off) the stop lamp are disclosed.

JP 2003-63274 A

  However, even if a configuration for turning on the brake lamp during automatic braking control is added as in the technique disclosed in the above-mentioned Patent Document 1, it may be difficult to turn on the brake lamp at an appropriate timing. As one of such cases, for example, a case where the driver operates the brake pedal in a state where the hydraulic pressure by the automatic braking control remains in the master cylinder is assumed. In other words, when the driver operates the brake pedal while the hydraulic pressure from the automatic braking control remains in the master cylinder, it is usually controlled by a small amount of operation (stroke) that is a dead zone of the brake lamp switch. In some cases, power is generated and the brake lamp is not lit despite the fact that deceleration is actually occurring, which is desirable to turn on the brake lamp.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a vehicle driving support device capable of lighting a brake lamp at an appropriate timing when a braking force exceeding a predetermined level is generated.

A vehicle driving support apparatus according to an aspect of the present invention includes a master cylinder that generates a brake fluid pressure corresponding to an operation amount of a brake pedal and supplies the brake fluid pressure to a wheel cylinder, and a brake fluid pressure independent of the operation amount of the brake pedal. And a brake control means for performing automatic braking control through supply control of brake fluid pressure generated by the fluid pressure source to the wheel cylinder. The first switch means for turning on the brake lamp when the operation amount is equal to or greater than the set amount, the second switch means for turning on the brake lamp independently of the brake pedal, and the second switch means Lighting control means for controlling the switch means, the lighting control means, when the hydraulic pressure of the master cylinder is equal to or higher than a set value, Is lit the brake lamp is turned on the second switching means when said first switching means is turned on, which prohibits the ON operation of the second switching means based on the hydraulic pressure of the master cylinder It is .

  According to the vehicle driving support device of the present invention, the brake lamp can be turned on at an appropriate timing when a braking force exceeding a predetermined level is generated.

Schematic configuration diagram of a vehicle driving support device Schematic configuration diagram of brake fluid pressure control circuit Flow chart showing brake lamp lighting control routine Timing chart showing an example of the relationship between the master cylinder hydraulic pressure and the trigger, relay switch, and brake lamp switch

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In FIG. 1, reference numeral 1 denotes, for example, a cruise control with an inter-vehicle distance control (ACC; Adaptive Cruise Control) that selectively performs a follow-up running control and a constant speed running control according to the state of catching a preceding vehicle ahead of the host vehicle. 1 shows a vehicle driving support device having a function. In the present embodiment, the driving support device 1 is configured around a preview control unit (PCU) 5. More specifically, the driving support apparatus 1 includes various control devices such as an engine control device (E / G_ECU) 6, a transmission control device (T / M_ECU) 7, and a brake control device (BRK_ECU) 8 with respect to the PCU 5. The main part is configured to be connected to each other through CAN (Controll Area Network) communication or the like.

  In the present embodiment, the PCU 5 is configured to integrally include a laser radar 5a as a sensor for recognizing information outside the vehicle ahead of the vehicle, for example. The laser radar 5a includes a light emitting unit and a light receiving unit (not shown). The light emitting unit and the light receiving unit are exposed to the outside of the vehicle above the front bumper, for example, by placing the PCU 5 at the front of the vehicle body. ing. As a result, the laser radar can emit laser light from the light emitting unit toward the front of the host vehicle, and by detecting the reflected light of the laser light at the receiving unit, it can detect the preceding vehicle and the like. It is possible to do.

  Further, the PCU 5 receives, for example, operation signals from the ACC operation switch 10 for performing various settings for ACC travel, various detection signals from the accelerator opening sensor 11 and the brake pedal sensor 12, and the like through the E / G_ECU 6. Is done. Here, the ACC operation switch 10 includes, for example, a plurality of switches disposed on the steering wheel. Specifically, the ACC operation switch 10 is a cruise switch that instructs execution (ON) of ACC travel, a cancel switch that instructs stop (OFF) of ACC travel, ACC, or vehicle speed ( A set / coast switch that changes the set vehicle speed Vset) to the lower side, a resume / accelerate switch that resets the set vehicle speed Vset to the higher side, or a resume / accelerate switch that changes the set vehicle speed Vset to the higher side (not shown) It is configured with switches.

  Further, for example, various signals indicating the host vehicle speed V detected by the vehicle speed sensor 15 are input to the PCU 5 via the T / M_ECU 7.

  Further, the PCU 5 includes, for example, a master cylinder hydraulic pressure Pm, a wheel cylinder hydraulic pressure Ph, and the like from a master cylinder hydraulic pressure sensor 21 and a wheel cylinder hydraulic pressure sensor 22 that are disposed on a brake device 20 described later. A signal and various signals indicating an on / off state of a brake lamp switch 54 disposed on a brake lamp lighting circuit 50 described later are input via the BRK_ECU 8.

  As shown in FIG. 2, the brake device 20 of the present embodiment has a master cylinder 27 connected to a brake pedal 25 via a booster 26, and the master cylinder 27 is connected to each wheel via a hydraulic unit 30. The main part is configured to communicate with the wheel cylinder 28.

  The hydraulic unit 30 has a pressure reducing solenoid valve 32 interposed in the middle of each brake pipe line 31 communicating the master cylinder 27 and each wheel cylinder 28, and a relief valve 33 that bypasses the pressure reducing solenoid valve 32. The hydraulic unit 30 has an oil pump 36 as a hydraulic pressure source driven by a motor 35, and a pipe 37 connected to the oil reservoir 29 of the master cylinder 27 communicates with the suction side of the oil pump 36. ing. On the other hand, the discharge side pipe line 38 of the oil pump 36 communicates with the relief valve 40 via the check valve 39 and further communicates with the accumulator 41 so as to accumulate pressure. Further, on the downstream side of each pressure reducing solenoid valve 32, the pipe line 38 is communicated with the brake pipe line 31 via the pressurizing solenoid valve 42.

  Here, the pressure reducing solenoid valve 32 is constituted by a normally open solenoid valve, which opens when the power is off and closes when the power is on. On the other hand, the pressurizing solenoid valve 42 is configured by a normally closed solenoid valve, which is closed when de-energized and is opened when energized. As a result, when the pressure solenoid valve 42 is turned off and the pressure reducing solenoid valve 32 is turned off, the hydraulic pressure generated in the master cylinder 27 according to the amount of operation of the brake pedal 25 by the driver is supplied to the wheel cylinder 28. It becomes possible to perform normal footbrake that is supplied and generates braking force. On the other hand, when the pressure reducing solenoid valve 32 is turned on and closed, and the pressure solenoid valve 42 is turned on with a predetermined duty ratio, the hydraulic pressure of the wheel cylinder 28 is increased (increased control) by the accumulator pressure. . When the pressure reducing solenoid valve 32 is turned on and closed, and the pressure solenoid valve 42 is turned off, the increased hydraulic pressure is contained in the wheel cylinder 28 and held. When the pressurizing solenoid valve 42 is turned off and the pressure reducing solenoid valve 32 is turned off at a predetermined duty ratio, the hydraulic pressure in the wheel cylinder 28 is released via the master cylinder 27 ( The pressure is controlled).

  The BRK_ECU 8 can perform automatic braking control by appropriately feedback-controlling the brake pressure supplied to the wheel cylinder 28 through pressurization, holding, and decompression, thereby realizing a function as a brake control means. To do.

  As shown in FIG. 1, the brake lamp lighting circuit 50 for lighting the brake lamp 52 at the time of braking has a main wiring 53 that connects the battery power source 51 to the brake lamp 52. Is provided with a brake lamp switch 54 as a first switch means. As shown in FIG. 2, the brake lamp switch 54 is a normally open switch that is turned off by contact with the brake pedal 25 when not operated, and when the operation amount of the brake pedal 25 reaches a predetermined value or more, It is separated from the brake pedal 25 and turned on.

  Further, a sub-wiring 55 that bypasses the brake lamp switch 54 is provided in the middle of the main wiring 53, and further, the connection to the brake lamp 52 is selectively switched between the brake lamp switch 54 side and the sub-wiring 55 side. The relay switch 56 is interposed. This relay switch 56 realizes a function as a second switch means for lighting the brake lamp 52 independently of the brake lamp switch 54 by turning on the auxiliary wiring 55 side with respect to the brake lamp 52.

  Here, the voltage signal between the brake lamp switch 54 and the relay switch 56 and the voltage signal between the relay switch 56 and the brake lamp 52 are input to the BRK_ECU 8 through the respective signal lines 57a and 57b. By monitoring these voltage signals, the BRK_ECU 8 can detect the on / off state of the brake lamp switch 54.

  In such a configuration, when the execution of the ACC travel is instructed based on the operation input of the ACC operation switch 10 of the driver while the host vehicle is traveling, the PCU 5 detects (captures) the preceding vehicle through the laser radar 5a. . When the preceding vehicle is not captured by the laser radar 5a, the PCU 5 sets the set vehicle speed Vset as the target vehicle speed Vt. On the other hand, when the preceding vehicle is supplemented, the PCU 5 sets a target inter-vehicle distance Dt based on the preceding vehicle speed, and obtains a target vehicle speed Vt for maintaining the target inter-vehicle distance Dt. Based on the set target vehicle speed Vt, the PCU 5 calculates the target throttle opening degree θαs and outputs a signal to the E / G_ECU 6, and calculates the pseudo accelerator opening degree θha and outputs the signal to the T / M_ECU 7. . As a result, the E / G_ECU 6 controls an electronically controlled throttle device (not shown) so that the opening of the throttle valve converges to the target throttle opening θαs. Further, the T / M_ECU 7 performs a shift control by outputting a shift signal to a control valve (not shown) in accordance with a shift pattern set based on the pseudo accelerator opening θha.

  At this time, as a result of the preceding vehicle decelerating by actuating a brake or the like, the inter-vehicle distance between the host vehicle and the preceding vehicle becomes shorter than the target inter-vehicle distance Dt, and the inter-vehicle distance is returned to the target inter-vehicle distance Dt only with the engine brake. If it is not possible, the PCU 5 calculates the target deceleration Gt for maintaining the inter-vehicle distance from the preceding vehicle, and outputs it to the BRK_ECU 8. Thereby, the BRK_ECU 8 supplies the brake hydraulic pressure corresponding to the target deceleration Gt to the wheel cylinder 28 through the control on the hydraulic unit 30, and performs automatic braking control.

  In addition, in order to properly light the brake lamp 52 including during such automatic braking control, the PCU 5 controls the lighting of the brake lamp 52 through connection control (ON control) of the relay switch 56 to the sub wiring 55 side. I do.

  In this lighting control, the PCU 5 basically has a large braking force generated by the automatic braking control when the control hydraulic pressure applied to the wheel cylinder 28 by the automatic braking control is equal to or higher than a preset threshold value. The relay switch 56 is turned on to the sub wiring 55 side, and the brake lamp 52 is forcibly lit independently of the brake lamp switch 54.

  In addition, when the master cylinder hydraulic pressure Pm is equal to or higher than a set value P0 (for example, P0 = 0.35 MPa), the PCU 5 turns on the relay switch 56 to the sub wiring 55 side and lights the brake lamp 52. However, for the purpose of ensuring the durability of the relay switch 56, etc., the PCU 5 allows the ON operation of the relay switch 56 in order to limit the operation frequency of the relay switch 56 based on the master cylinder hydraulic pressure Pm to the minimum necessary. When the trigger T is set, and the trigger T is released, the ON operation of the relay switch 56 is prohibited. Further, the PCU 5 prohibits the ON operation of the relay switch 56 when the brake lamp switch 54 is turned on.

  Here, for example, the PCU 5 sets the trigger T on condition that the master cylinder hydraulic pressure Pm becomes equal to or higher than the set value P0 during execution of the automatic braking control. On the other hand, the PCU 5 has, for example, that at least one of the master cylinder hydraulic pressure Pm and the wheel cylinder hydraulic pressure Ph during traveling of the host vehicle has dropped to the hydraulic pressure at the time of brake release, or automatic braking control is started. The trigger T is canceled on the condition.

  Thus, in this embodiment, PCU5 implement | achieves each function as a lighting control means and a trigger setting means.

  Next, lighting control for the brake lamp 52 executed by the PCU 5 will be described according to the flowchart of the brake lamp lighting control routine shown in FIG. This routine is repeatedly executed every predetermined time. When the routine is started, the PCU 5 checks in step S101 whether or not the automatic braking control is currently being executed.

  If it is determined in step S101 that automatic braking control is not being performed, the PCU 5 proceeds to step S104.

  On the other hand, if it is determined in step S101 that automatic braking control is being performed, the PCU 5 proceeds to step S102 and determines whether or not the master cylinder hydraulic pressure Pm is higher than a set hydraulic pressure P0 (for example, P0 = 0.35 MPa). Investigate.

  If it is determined in step S102 that the master cylinder hydraulic pressure Pm is equal to or lower than the set hydraulic pressure P0, the PCU 5 proceeds to step S104.

  On the other hand, if it is determined in step S102 that the master cylinder hydraulic pressure Pm is higher than the set hydraulic pressure P0, the PCU 5 proceeds to step S103, sets the trigger T, and then proceeds to step S104. That is, as a case where the master cylinder hydraulic pressure Pm becomes higher than the set hydraulic pressure P0 during the automatic braking control, for example, the hydraulic pressure supplied from the oil pump 36 side into the wheel cylinder 28 is oiled via the master cylinder 27. When releasing into the reservoir 29, the flow path to the oil reservoir 29 is blocked by the master cylinder 27 by the driver's brake operation, and the master cylinder hydraulic pressure Pm is increased. Therefore, in such a case, since there is a high possibility that a high hydraulic pressure is supplied to the wheel cylinder 28 by a slight brake operation by the driver, the PCU 5 sets the trigger T.

  When the process proceeds from step S101, step S102, or step S103 to step S104, the PCU 5 checks whether a release condition for a preset trigger T is satisfied. That is, in step S104, as a release condition for the trigger T, the PCU 5, for example, at least one of the master cylinder hydraulic pressure Pm and the wheel cylinder hydraulic pressure Ph during traveling of the host vehicle drops to the hydraulic pressure at the time of brake release. It is checked whether or not automatic braking control is newly started.

  If it is determined in step S104 that the release condition for the trigger T is not satisfied, the PCU 5 proceeds to step S106.

  On the other hand, if it is determined in step S104 that the release condition for the trigger T is satisfied, the PCU 5 proceeds to step S105, releases the trigger T, and then proceeds to step S106.

  When the process proceeds from step S104 or step S105 to step S106, the PCU 5 checks whether or not the control hydraulic pressure by the automatic braking control is equal to or higher than the set threshold value.

  If it is determined in step S106 that the control hydraulic pressure by the automatic braking control is equal to or greater than the set threshold value and a large braking force is currently generated by the automatic braking control, the PCU 5 proceeds to step S110.

  On the other hand, when it is determined in step S106 that the control hydraulic pressure by the automatic braking control is less than the set threshold value and no large braking force is currently generated by the automatic braking control, the PCU 5 proceeds to step S107.

  When the process proceeds from step S106 to step S107, the PCU 5 checks whether or not the master cylinder hydraulic pressure Pm is higher than a set value P0 sufficient to generate a braking force greater than or equal to a predetermined value.

  If it is determined in step S107 that the master cylinder hydraulic pressure Pm is less than or equal to the set value P0, the PCU 5 proceeds to step S111.

  On the other hand, if it is determined in step S107 that the master cylinder hydraulic pressure Pm is higher than the set value P0, the PCU 5 proceeds to step S108 and checks whether the trigger T is set.

  If it is determined in step S108 that the trigger T is not set, the PCU 5 proceeds to step S111.

  On the other hand, if it is determined in step S108 that the trigger T is set, the PCU 5 proceeds to step S109 and checks whether or not the brake lamp switch 54 is turned off.

  If it is determined in step S109 that the brake lamp switch 54 is turned off, the PCU 5 proceeds to step S110.

  On the other hand, if it is determined in step S109 that the brake lamp switch 54 is turned on, the PCU 5 proceeds to step S111.

  When the process proceeds from step S106 or step S109 to step S110, the PCU 5 exits the routine after performing connection control (ON control) of the relay switch 56 to the sub wiring 55 side. Thereby, the brake lamp 52 is turned on without depending on the brake lamp switch 54.

  On the other hand, when the process proceeds from step S107, step S108, or step S109 to step S111, the PCU 5 performs connection control (off control) to the brake lamp switch 54 side of the relay switch 56, and then exits the routine. As a result, the brake lamp 52 is turned on in conjunction with the on / off state of the brake lamp switch 54.

  According to such an embodiment, not only when the control hydraulic pressure by the automatic braking control is equal to or higher than the threshold value, but also when the master cylinder hydraulic pressure Pm is equal to or higher than the set value P0, the relay switch 56 is connected to the sub wiring 55 side. And the brake lamp 52 is turned on without depending on the brake lamp switch 54, for example, the state in which the hydraulic pressure by the automatic braking control remains in the master cylinder 27 (that is, applied to the wheel cylinder 28). When the driver operates the brake pedal 25 while the hydraulic pressure is being released to the oil reservoir 29 via the master cylinder 27), the master cylinder 27 is operated by a normal depression operation using the remaining pressure. Even when a hydraulic pressure higher than the hydraulic pressure generated in the brake lamp 5 is generated, the brake lamp 5 is It can be turned (for example, see in Fig. 4 t1 to t4).

  In this case, even when the master cylinder hydraulic pressure Pm is higher than the set value P0, the brake lamp switch 54 is turned on when the trigger T is not set (for example, see t5 to t6 in FIG. 4). (For example, refer to t2 to t3 and t5 to t6 in FIG. 4), by prohibiting the ON operation of the relay switch 56 to the sub wiring 55 side, the unnecessary operation of the relay switch 56 is suppressed. , Durability can be improved. That is, when the master cylinder hydraulic pressure Pm is higher than the set value P0 and the trigger T is not set, or when the brake lamp switch 54 is turned on, the liquid in the master cylinder 27 is controlled by automatic braking control. When the normal foot brake operation is performed with no pressure remaining, or when the brake lamp 52 can be properly turned on by the normal operation of the brake lamp switch 54 even if the hydraulic pressure remains. is assumed. Therefore, in such a case, it is not necessary to turn on the relay switch 56 and turn on the brake lamp 52. By suppressing the on operation in such a case, the durability of the relay switch 56 can be improved. Can do.

DESCRIPTION OF SYMBOLS 1 ... Vehicle driving assistance device 5 ... Preview control unit (braking control means, lighting control means, trigger setting means)
DESCRIPTION OF SYMBOLS 5a ... Laser radar 6 ... Engine control device 7 ... Transmission control device 8 ... Brake control device 10 ... ACC operation switch 11 ... Accelerator opening sensor 12 ... Brake pedal sensor 15 ... Vehicle speed sensor 20 ... Brake device 21 ... Master cylinder hydraulic pressure sensor DESCRIPTION OF SYMBOLS 22 ... Wheel cylinder hydraulic pressure sensor 25 ... Brake pedal 26 ... Booster 27 ... Master cylinder 28 ... Wheel cylinder 29 ... Oil reservoir 30 ... Hydraulic unit 31 ... Brake line 32 ... Pressure-reducing solenoid valve 33 ... Relief valve 35 ... Motor 36 ... Oil Pump (hydraulic pressure source)
37 ... Pipe line 38 ... Discharge side pipe 39 ... Check valve 40 ... Relief valve 41 ... Accumulator 42 ... Pressure solenoid valve 50 ... Brake lamp lighting circuit 51 ... Battery power supply 52 ... Brake lamp 53 ... Main wiring 54 ... Brake lamp switch (First switch means)
55 ... Sub wiring 56 ... Relay switch (second switch means)
57a, 57b ... signal lines

Claims (3)

A master cylinder that generates brake fluid pressure according to the amount of operation of the brake pedal and supplies the brake cylinder to the wheel cylinder, a fluid pressure source that generates brake fluid pressure independent of the amount of operation of the brake pedal, and the fluid pressure source In a vehicle driving support apparatus comprising: a braking control unit that performs automatic braking control through supply control of the generated brake fluid pressure to the wheel cylinder;
First switch means for turning on the brake lamp when the operation amount of the brake pedal is equal to or greater than a set amount;
Second switch means for lighting the brake lamp independently of the brake pedal;
Lighting control means for controlling the second switch means,
The lighting control means turns on the second switch means to light the brake lamp when the hydraulic pressure of the master cylinder is equal to or higher than a set value ,
An on- vehicle driving support device , wherein when the first switch means is on, the on operation of the second switch means based on the hydraulic pressure of the master cylinder is prohibited . The lighting control means includes trigger setting means for setting a trigger on condition that the hydraulic pressure of the master cylinder is equal to or higher than a set value during execution of the automatic braking control,
  2. The vehicle driving support device according to claim 1, wherein when the trigger is released, the on-operation of the second switch unit based on the hydraulic pressure of the master cylinder is prohibited. The trigger setting means that at least one of the hydraulic pressure of the master cylinder or the hydraulic pressure of the wheel cylinder has dropped to the hydraulic pressure at the time of brake release, or that the automatic braking control has been started. The vehicle driving support device according to claim 2, wherein the trigger is released as a condition.

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