JP6258624B2 - Lane departure prevention system - Google Patents

Description

  The present invention relates to a lane departure prevention system.

  As a conventional lane departure prevention system, for example, as described in Patent Document 1, a lane is recognized by a monocular camera or the like, it is determined whether or not the vehicle deviates from the recognized lane, and it is determined to deviate. In this case, there is known one that transmits a signal for maintaining the position of the host vehicle in a lane to a control unit. In this lane departure prevention system, the steering actuator is controlled by calculating a steering assist torque to be applied to the steering actuator based on the signal. Further, the brake actuator is controlled by calculating a braking force required for the brake actuator based on the signal.

JP 2008-285013 A

  In the above conventional lane departure prevention system, in order to prevent lane departure, for example, a desired yaw motion is generated by steering control by a steering actuator or brake control of each wheel by a brake actuator. Therefore, the vehicle control of the host vehicle can be performed, but the cost is high and the generalization is difficult. Therefore, as an existing system with low cost and generalization, when it is determined that the vehicle may deviate from the lane, a warning is given with a buzzer or display to alert the driver. There is a lane departure warning system. However, this lane departure warning system cannot control the vehicle.

  Accordingly, an object of the present invention is to provide a lane departure prevention system capable of vehicle control related to lane departure prevention of the host vehicle with a simple configuration and low cost.

  In order to solve the above problems, a lane departure prevention system according to the present invention is a lane departure prevention system for preventing a lane departure of a host vehicle, and is recognized by a lane recognition unit that recognizes a lane and a lane recognition unit. Vehicle lane departure determining means for determining the possibility of lane departure of the host vehicle with respect to the lane, and vehicle control means for performing vehicle control of the host vehicle in accordance with a determination result by the lane departure determining means. When it is determined by the lane departure determination means that there is a possibility of lane departure, the engine is brought into an engine brake state and decelerated.

  In the lane departure prevention system of the present invention, when there is a possibility of lane departure of the host vehicle, the engine can be decelerated in the engine brake state regardless of the accelerator operation by the driver. That is, for example, the vehicle control for preventing the lane departure of the host vehicle can be performed without performing the steering control by the steering actuator or the brake control of each wheel by the brake actuator. Therefore, vehicle control related to prevention of lane departure of the host vehicle can be performed with a simple configuration and low cost.

  In addition, the vehicle control means sets the engine to the engine brake state after a certain period of time has passed without a winker operation or a brake operation of the host vehicle when the lane departure determination means determines that there is a possibility of lane departure. It is preferable to decelerate. By comprising in this way, the deceleration by an engine brake state can be performed suitably according to a driver | operator's lane change or a driver | operator's deceleration operation.

  Further, the vehicle control means includes a hold circuit that outputs a voltage when the accelerator operation is not performed by the driver, and an engine control unit that controls the engine, an accelerator sensor that outputs a voltage according to the amount of the accelerator operation, or A switching relay that is switchably connected to one of the hold circuits, and when the lane departure determining means determines that there is a possibility of lane departure, the switching relay connects the engine control unit to the hold circuit. Thus, it is preferable to decelerate by setting the engine in an engine brake state. In this case, the present invention can be easily applied to an existing system and can be highly versatile.

  Further, the vehicle control means further comprises own vehicle return determination means for determining whether or not the position of the own vehicle has returned within the lane recognized by the lane recognition means, and the vehicle control means determines the position of the own vehicle by the own vehicle return determination means. When it is determined that the vehicle has returned to the lane, it is preferable to connect the engine control unit to the accelerator sensor by a switching relay and output a voltage corresponding to the amount of accelerator operation by the driver to the engine control unit. With this configuration, when the position of the host vehicle returns to the lane, vehicle control of the host vehicle according to the amount of accelerator operation by the driver can be performed as usual.

  In addition, it is preferable that the vehicle further includes a lane departure warning unit that issues a warning when the lane departure determination unit determines that there is a possibility of a lane departure of the host vehicle. With this configuration, when there is a possibility that the host vehicle deviates from the lane, the driver can be alerted by an alarm.

  ADVANTAGE OF THE INVENTION According to this invention, the vehicle control which concerns on the lane departure prevention of the own vehicle is attained by simple structure and low cost.

It is a block diagram which shows the structure of the lane departure prevention system which concerns on 1st Embodiment. It is a flowchart which shows an example of the processing content in the lane departure prevention system of FIG. It is a block diagram which shows the structure of the lane departure prevention system which concerns on 2nd Embodiment.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, the same or equivalent elements will be denoted by the same reference numerals, and redundant description will be omitted.

[First Embodiment]
FIG. 1 is a block diagram showing the configuration of the lane departure prevention system according to the first embodiment. As shown in FIG. 1, the lane departure prevention system 1 is a system that is mounted on the host vehicle V and performs vehicle control for preventing the departure of the host vehicle V. Examples of the host vehicle V include large vehicles such as trucks, buses, and heavy machinery, and medium-sized vehicles.

  The lane departure prevention system 1 includes a lane sensor 2 that detects a lane in which the host vehicle V travels, a winker operation switch 3 that detects a winker operation of the host vehicle V, and a brake operation switch that detects a brake operation of the host vehicle V. 4, a lane departure ECU 5 that performs various processes for preventing lane departure, a switching relay 7 that enables an engine control ECU (engine control unit) 6 that controls the engine to be connected to the lane departure ECU 5, and lane departure prevention And an alarm device 8 for generating an alarm for the purpose. The lane departure ECU 5 and the engine control ECU 6 are each configured by a CPU that performs arithmetic processing, a ROM and a RAM that serve as a storage unit, an input signal circuit, an output signal circuit, a power supply circuit, and the like.

  The lane sensor 2 is, for example, a monocular camera disposed at the front center of the host vehicle V, and acquires an image of the road surface in front of the host vehicle V through the windshield. The acquired image may be either a color image (for example, an RGB image) or a black and white image as long as the lane recognition means described below can recognize the lane. Information on the image acquired by the lane sensor 2 is output to the lane departure ECU 5.

  The winker operation switch 3 is provided, for example, in a winker (direction indicator) (not shown) or a device related thereto, and detects the driver's winker operation. The winker operation switch 3 is turned on when the winker operation is performed, and is turned off when there is no winker operation. An on / off signal from the winker operation switch 3 is output to the lane departure ECU 5.

  The brake operation switch 4 is provided, for example, on a brake pedal (not shown) or a device related thereto, and detects a driver's brake operation on the brake pedal. The brake operation switch 4 is turned on when the brake operation amount exceeds a predetermined amount, and turned off when the brake operation amount becomes equal to or less than the predetermined amount. An on / off signal from the brake operation switch 4 is output to the lane departure ECU 5.

  The lane departure ECU 5 performs various processes for controlling the host vehicle V based on output signals from the lane sensor 2, the blinker operation switch 3, and the brake operation switch 4. The lane departure ECU 5 functions as lane recognition means, lane departure determination means, vehicle control means, and own vehicle return determination means described in the claims. Details of the functions of the lane departure ECU 5 will be described later.

  The switching relay 7 connects the engine control ECU 6 to either one of the lane departure ECU 5 or the accelerator sensor 9 that detects an accelerator operation by the driver. The accelerator sensor 9 is a sensor that detects an accelerator operation amount with respect to an accelerator pedal for accelerating the host vehicle V. For example, the switching relay 7 is turned off to connect the engine control ECU 6 to the accelerator sensor 9 and is turned on to connect the engine control ECU 6 to the lane departure ECU 5. The switching relay 7 functions as vehicle control means described in the claims.

  If the lane departure ECU 5 determines that there is a possibility of lane departure, the warning device 8 notifies that there is a possibility of lane departure according to the output of the determination result from the lane departure ECU 5. The warning device 8 here is a warning lamp, a warning buzzer, or the like, and generates a light or sound warning according to the determination of the possibility of lane departure in the lane departure ECU 5 to alert the driver. The warning device 8 has a function as lane departure warning means described in the claims.

  Next, details of the functions of the above-described lane departure ECU 5 will be described.

  The lane departure ECU 5 recognizes the lane in which the host vehicle V travels based on the image information output from the lane sensor 2. For example, image processing is performed on an image of the road surface ahead of the host vehicle V acquired by the lane sensor 2, and road sections (hereinafter simply referred to as “white lines”) that divide both ends of the lane in which the host vehicle V is traveling. ) Is detected.

  Further, the lane departure ECU 5 determines the possibility of the lane departure of the host vehicle V with respect to the recognized lane. For example, the distance between the white line detected by image processing and the host vehicle V is calculated, and it is determined whether there is a possibility of lane departure from the displacement. The possibility of departure from the lane may include not only the possibility of departure but also the possibility of departure.

  The lane departure ECU 5 includes an output circuit 10 that outputs a signal corresponding to the possibility of lane departure, and a hold circuit 11 that outputs a fixed voltage. The output circuit 10 outputs a command signal related to operation or non-operation to the alarm device 8 depending on whether or not there is a possibility of lane departure. Further, the output circuit 10 outputs a switching signal for switching on or off of the switch to the switching relay 7 in accordance with the possibility of lane departure. The hold circuit 11 holds the same fixed voltage as when the accelerator pedal is released (when the driver does not depress the accelerator pedal), and outputs the fixed voltage to the engine control ECU 6. The fixed voltage is, for example, a voltage when the engine is in an idle state, and is read from the engine control ECU 6 by the idle switch 12 and is held by the hold circuit 11.

  In particular, when the lane departure ECU 5 determines that there is a possibility of lane departure, a state in which there is no blinker operation or brake operation of the host vehicle V based on output signals from the blinker operation switch 3 and the brake operation switch 4 has elapsed for a certain period of time. Determine whether or not. When the lane departure ECU 5 determines that there is a possibility of lane departure and there is no blinker operation or brake operation of the host vehicle V for a certain period of time, the lane departure ECU 5 sends a switching signal for switching the switch to the on state from the output circuit 10. Output to the switching relay 7. As a result, the engine control ECU 6 is connected to the hold circuit 11, and as a result, a fixed voltage held in the hold circuit 11 is output to the engine control ECU 6, and the engine enters an engine brake state. Note that the certain time is, for example, the time required for the driver to change lanes.

  On the other hand, if the lane departure ECU 5 determines that there is no possibility of lane departure, the lane departure ECU 5 outputs a switching signal for switching to a state in which the switch is turned off from the output circuit 10 to the switching relay 7. As a result, the engine control ECU 6 is connected to the accelerator sensor 9, and as a result, a voltage corresponding to the actual amount of accelerator operation by the driver is output from the accelerator sensor 9 to the engine control ECU 6.

  Further, the lane departure ECU 5 determines whether or not the position of the host vehicle V has returned to the lane when there is a possibility of lane departure. When the lane departure ECU 5 determines that the position of the host vehicle V has returned to the lane, the lane departure ECU 5 outputs a switching signal for switching the switch to the off state, similarly to the case where it is determined that there is no possibility of lane departure. Output from the circuit 10 to the switching relay 7. As a result, the engine control ECU 6 is connected to the accelerator sensor 9, and as a result, a voltage corresponding to the actual amount of accelerator operation by the driver is output from the accelerator sensor 9 to the engine control ECU 6.

  Next, the flow of lane departure prevention processing executed by the lane departure prevention system 1 will be described with reference to FIG. FIG. 2 is a flowchart showing an example of processing contents in the lane departure prevention system of FIG.

  As shown in FIG. 2, first, the lane departure ECU 5 determines the presence or absence of a winker operation based on a detection signal from the winker operation switch 3 (S1). When there is no blinker operation (S1; Yes), the lane departure ECU 5 determines whether or not there is a possibility of lane departure (S2). On the other hand, if there is a blinker operation (S1; No), the process proceeds to step S4 described later without determining whether there is a possibility of lane departure.

  Subsequently, when it is determined that there is a possibility of lane departure (S2; Yes), the alarm device 8 activates an alarm (S3). On the other hand, when it is determined that there is no possibility of lane departure (S2; No), the alarm is not activated and the process proceeds to step S7 described later (S4).

  Subsequently, based on signals from the winker operation switch 3 and the brake operation switch 4, the lane departure ECU 5 determines whether or not a certain period of time has elapsed without a winker operation or without a brake operation (S5).

  When the state where there is no blinker operation or no brake operation has elapsed for a certain time (S5; Yes), the switch of the switching relay 7 is turned on (S6). That is, the engine control ECU 6 is connected to the hold circuit 11. As a result, the fixed voltage held in the hold circuit 11 is output to the engine control ECU 6, the engine enters the engine brake state, and the host vehicle V is decelerated by the engine brake.

  On the other hand, when the state where there is no blinker operation or no brake operation has not elapsed for a predetermined time (S5; No), the switch of the switching relay 7 is turned off (S7). That is, the engine control ECU 6 is connected to the accelerator sensor 9. As a result, a voltage corresponding to the actual amount of accelerator operation by the driver is output from the accelerator sensor 9 to the engine control ECU 6, and the host vehicle V travels at the engine torque and engine speed corresponding to the accelerator operation. Become. And after passing through step S6 or step S7, it transfers to the said step S1 and repeats a process.

  In such a lane departure prevention system 1, when the position of the host vehicle V that deviates from the lane returns to the lane, the engine control ECU 6 is connected to the accelerator sensor 9 as follows, and the amount of accelerator operation by the driver is as follows. Is output to the engine control ECU 6. That is, when the switch of the switching relay 7 is on (S6), the lane departure ECU 5 determines whether there is a possibility of lane departure (S2), and when there is no possibility of lane departure (S2; No). Assuming that the position of the host vehicle V has returned to the lane, the switch of the switching relay 7 is turned off (S7), and the engine control ECU 6 is connected to the accelerator sensor 9. As a result, a voltage corresponding to the actual amount of accelerator operation by the driver is output from the accelerator sensor 9 to the engine control ECU 6.

  As described above, according to the lane departure prevention system 1 of the present embodiment, when there is a possibility of the lane departure of the host vehicle V, the engine can be decelerated and decelerated regardless of the accelerator operation by the driver. That is, for example, vehicle control for preventing the vehicle V from departing from the lane can be performed without performing steering control by the steering actuator or brake control of each wheel by the brake actuator. Therefore, vehicle control related to prevention of lane departure of the host vehicle V is possible with a simple configuration and low cost.

  Further, in the lane departure prevention system 1, as described above, when it is determined that there is a possibility of lane departure, the engine brake is performed after a certain period of time when there is no blinker operation or brake operation of the host vehicle V. Decelerate and slow down. Thereby, the deceleration by an engine brake state can be performed suitably corresponding to the driver | operator's lane change or a driver | operator's deceleration operation. For example, deceleration by engine braking can be performed only when the driver does not change lanes or decelerate even after a certain grace period elapses after the lane departure warning is activated. As a result, for example, when the lane change is made simply by forgetting the blinker operation, it is possible to prevent the rear vehicle from being collided.

  In the lane departure prevention system 1, as described above, the vehicle control related to the lane departure prevention of the host vehicle V can be performed by the configuration including the vehicle departure ECU 5 having the hold circuit 11 and the switching relay 7. As a result, retrofit such as improvement by applying to an existing system is possible, and it can be highly versatile and can be commercialized as an aftermarket product.

  Further, in the lane departure prevention system 1, as described above, when it is determined that the position of the host vehicle V has returned to the lane, the vehicle of the host vehicle V according to the amount of accelerator operation by the driver as usual. Control can be performed.

  Further, in the lane departure prevention system 1, as described above, when there is a possibility of lane departure of the host vehicle V, it is possible to prompt the driver to be alerted by generating an alarm by the alarm device 8.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. In the description of the present embodiment, differences from the first embodiment will be mainly described.

  FIG. 3 is a block diagram showing a configuration of a lane departure prevention system according to the second embodiment. As shown in FIG. 3, the lane departure prevention system 100 according to this embodiment is different from the lane departure prevention system 1 in that the switching relay 7, the output circuit 10, and the hold circuit 11 are not provided. Yes (see FIG. 1).

  The lane departure prevention system 100 performs vehicle control similar to the above by communicating between the lane departure ECU 5 and the engine control ECU 6. Specifically, when the lane departure ECU 5 determines that there is a possibility of lane departure, the vehicle lane departure ECU 5 changes to the engine control ECU 6 after a certain period of time has passed without a winker operation or a brake operation of the host vehicle V. On the other hand, a signal indicating that there is a possibility of lane departure is transmitted. When receiving the signal, the engine control ECU 6 additionally incorporates a program for setting the engine in an engine brake state. As a result, the engine can be decelerated in the engine brake state regardless of the accelerator operation.

  On the other hand, if the lane departure ECU 5 determines that there is no possibility of lane departure, the lane departure ECU 5 transmits a signal indicating that there is no possibility of lane departure to the engine control ECU 6, and the engine control ECU 6 When the signal is received, control during normal operation is performed. As a result, control according to the amount of actual accelerator operation by the driver can be performed. Note that the communication may be wireless or wired.

  In the lane departure prevention system 100, the lane departure ECU 5 and the warning device 8 communicate with each other to transmit a determination result of the possibility of lane departure from the lane departure ECU 5 to the warning device 8. If there is a possibility of lane departure according to the determination result, the warning device 8 generates a sound or light to give a warning.

  As described above, this embodiment also has the same effect as that of the above-described embodiment, that is, the effect that the vehicle control for preventing the lane departure of the host vehicle V can be performed with a simple configuration and low cost. Moreover, according to this embodiment, it is not necessary to provide the switching relay 7, the output circuit 10, and the hold circuit 11. Therefore, the lane departure prevention system 100 is particularly suitable when mounted on the host vehicle V in advance and performing vehicle control related to the lane departure prevention of the host vehicle V.

  As mentioned above, although preferred embodiment of this invention was described, this invention is not limited to the said embodiment, It changed within the range which does not change the summary described in each claim, or applied to the other thing It may be a thing.

  For example, the host vehicle V to be applied is not limited to the above embodiment, and may be a normal passenger car, a small vehicle, a light vehicle, or the like. Further, the alarm device 8 is not limited to an alarm lamp, an alarm buzzer, or the like. For example, the alarm device 8 may perform an alarm by displaying characters, graphics, or the like on a display.

  Further, the winker operation switch 3 may acquire information related to the direction indicated by the winker instead of or in addition to the presence or absence of the winker operation, and may output the information to the lane departure ECU 5. Further, the brake operation switch 4 may acquire information on the amount of the brake operation instead of or in addition to the presence or absence of the brake operation, and output the information to the lane departure ECU 5.

  Further, the lane departure ECU 5 of the above embodiment assumes that the engine is in the engine braking state after a certain period of time has passed without the winker operation or brake operation of the host vehicle V, but there is no winker operation or brake operation of the host vehicle V. Regardless of whether or not the state has passed for a certain period of time, the engine may be put into an engine brake state and decelerated when it is determined that there is a possibility of lane departure.

  DESCRIPTION OF SYMBOLS 1 ... Lane departure prevention system, 5 ... Lane departure ECU (lane recognition means, lane departure determination means, vehicle control means, own vehicle return determination means), 6 ... Engine control ECU (engine control unit), 7 ... Switching relay, 8 ... warning device (lane departure warning means), 9 ... accelerator sensor.

Claims (4)

A lane departure prevention system for preventing a lane departure of the host vehicle,
Lane recognition means for recognizing the lane;
Lane departure determination means for determining the possibility of lane departure of the host vehicle with respect to the lane recognized by the lane recognition means;
Vehicle control means for performing vehicle control of the host vehicle according to a determination result by the lane departure determination means,
The vehicle control means includes
A hold circuit that outputs a voltage when the accelerator operation by the driver is not performed;
An engine control unit that controls the engine, and a switching relay that is switchably connected to either the accelerator sensor that outputs a voltage corresponding to the amount of the accelerator operation or the hold circuit,
When it is determined by the lane departure determining means that there is a possibility of lane departure, steering control by a steering actuator and brake control of each wheel by a brake actuator are not performed, and the engine control unit is held by the switching relay by the hold circuit. A lane departure prevention system in which the engine is braked and decelerated regardless of the accelerator operation by the driver .   When the vehicle lane departure determining unit determines that there is a possibility of a lane departure, the vehicle control unit performs engine braking on the engine after a certain period of time has passed without a winker operation or a brake operation of the host vehicle. The lane departure prevention system according to claim 1, wherein the lane departure prevention system is decelerated to a state. A host vehicle return determination means for determining whether or not the position of the host vehicle has returned in the lane;
The vehicle control means connects the engine control unit to the accelerator sensor by the switching relay when the own vehicle return determination means determines that the position of the own vehicle has returned to the lane, and The lane departure prevention system according to claim 1 or 2 , wherein a voltage corresponding to an accelerator operation amount by a person is output to the control unit of the engine. The lane departure prevention unit according to any one of claims 1 to 3 , further comprising a lane departure warning unit that issues a warning when the lane departure determination unit determines that there is a possibility of lane departure of the host vehicle. system.

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