JP5565681B2 - Inter-vehicle distance control device - Google Patents

Description

  The present invention relates to an inter-vehicle distance control device that controls acceleration / deceleration of a host vehicle, appropriately keeps the headway distance between the host vehicle and a preceding vehicle, and causes the preceding vehicle to travel following the host vehicle.

  Japanese Patent Laid-Open No. 2006-335129 discloses fuel consumption caused by excessive deceleration of the host vehicle when the host vehicle approaches the preceding vehicle and the inter-vehicle distance L becomes equal to or less than the target inter-vehicle distance S1 (L ≦ S1). An inter-vehicle distance control device that can suppress the deterioration of the rate is described. In this inter-vehicle distance control device, the cancellation inter-vehicle distance S3 (S1> S3> S2) is set between the target inter-vehicle distance S1 and the approaching inter-vehicle distance S2, and the inter-vehicle distance L is greater than or equal to the cancellation inter-vehicle distance S3 and less than the target inter-vehicle distance S1. When the target acceleration / deceleration G is in the convergence direction, the acceleration / deceleration control of the host vehicle ends.

JP 2006-335129 A

  The inter-vehicle distance control device described in Japanese Patent Application Laid-Open No. 2006-335129 alleviates the conditions for performing acceleration control when the inter-vehicle distance between the preceding vehicle and the host vehicle is equal to or less than the target inter-vehicle distance, thereby improving the fuel consumption rate. However, the fuel consumption rate is not improved when the inter-vehicle distance between the preceding vehicle and the host vehicle exceeds the target inter-vehicle distance.

  Accordingly, an object of the present invention is to provide an inter-vehicle distance control device capable of improving the fuel consumption rate in a state where the inter-vehicle distance between the preceding vehicle and the host vehicle exceeds the target inter-vehicle distance.

  In order to achieve the above object, the inter-vehicle distance control device of the present invention comprises inter-vehicle distance detection means, speed detection means, target inter-vehicle distance setting means, and acceleration / deceleration control means.

The inter-vehicle distance detection means detects the inter-vehicle distance between the preceding vehicle and the host vehicle. The speed detection means detects the speed of the host vehicle. The target inter-vehicle distance setting means obtains a reference inter-vehicle distance based on the speed of the host vehicle detected by the speed detection means. When the inter-vehicle distance detected by the inter-vehicle distance detection means is equal to or less than the reference inter-vehicle distance, the reference inter-vehicle distance is set as the target inter-vehicle distance. The reference inter-vehicle distance, which is set as a distance, and when the inter-vehicle distance detected by the inter-vehicle distance detection means exceeds the reference inter-vehicle distance , the reference inter-vehicle distance and the inter-vehicle distance detected by the inter-vehicle distance detection means are added together at a predetermined ratio. The longer extended inter-vehicle distance is set as the target inter-vehicle distance. The acceleration / deceleration control means performs acceleration / deceleration control of the host vehicle so that the inter-vehicle distance detected by the inter-vehicle distance detection means approaches the target inter-vehicle distance.

  In the above configuration, the acceleration / deceleration control means performs acceleration / deceleration control of the host vehicle so that the inter-vehicle distance detected by the inter-vehicle distance detection means (hereinafter referred to as the detected inter-vehicle distance) approaches the target inter-vehicle distance. For example, when the detected inter-vehicle distance exceeds the target inter-vehicle distance, the acceleration / deceleration control means accelerates the own vehicle when the vehicle tends to increase from the preceding vehicle due to acceleration of the preceding vehicle. In addition, when the detected inter-vehicle distance is less than the target inter-vehicle distance and shows a decreasing tendency (when the host vehicle attempts to approach the preceding vehicle due to deceleration of the preceding vehicle), the acceleration / deceleration control means decelerates the host vehicle.

The target inter-vehicle distance setting means obtains a reference inter-vehicle distance based on the speed of the host vehicle (hereinafter referred to as detected vehicle speed) detected by the speed detecting means, and the detected inter-vehicle distance is used as the target inter-vehicle distance used by the acceleration / deceleration control means. If the distance is less than the reference distance, set the above-mentioned reference distance, and if the detected distance exceeds the reference distance, add the reference distance and the distance detected by the distance detector at a specified ratio. The extended inter-vehicle distance that is longer than the reference inter-vehicle distance is set.

  Therefore, for example, when the preceding vehicle decelerates, the host vehicle under the condition of following the vehicle while maintaining the target inter-vehicle distance with the preceding vehicle decelerates the reference inter-vehicle distance as the target inter-vehicle distance, When the preceding vehicle accelerates, the extended inter-vehicle distance that is longer than the reference inter-vehicle distance is accelerated as the target inter-vehicle distance. That is, the rear-end collision of the host vehicle with the preceding vehicle decelerating is avoided by setting the reference inter-vehicle distance as the target inter-vehicle distance. Further, the tracking of the preceding vehicle to be accelerated is mitigated as compared with the case where the reference inter-vehicle distance is set as the target inter-vehicle distance by setting the extended inter-vehicle distance longer than the reference inter-vehicle distance as the target inter-vehicle distance. In this way, when the preceding vehicle accelerates, excessive follow-up to the preceding vehicle is alleviated and the acceleration of the host vehicle is suppressed, so that the fuel consumption rate is prevented from deteriorating and the fuel consumption rate can be improved. it can.

Further, as the acceleration of the preceding vehicle increases (the rate of change in speed increases), the difference between the detected inter-vehicle distance and the reference inter-vehicle distance increases, and the extended inter-vehicle distance increases correspondingly and is set as the target inter-vehicle distance. Accordingly, excessive follow-up traveling is mitigated according to the magnitude of the acceleration of the preceding vehicle, and the fuel consumption rate can be improved accurately.

  Further, since the detected inter-vehicle distance can be calculated as a time integral value of the relative speed between the host vehicle and the preceding vehicle, it can be regarded as a time history of the relative speed between the host vehicle and the preceding vehicle. Therefore, the extended inter-vehicle distance considering the time history of the relative speed between the host vehicle and the preceding vehicle can be used as the target inter-vehicle distance when the detected inter-vehicle distance exceeds the reference inter-vehicle distance.

The inter-vehicle distance setting means may calculate a reference inter-vehicle distance by adding a distance obtained by multiplying the detected vehicle speed by a predetermined inter-vehicle time and a predetermined stop inter-vehicle distance. The inter-vehicle time is the time from the passage of the rear end of the preceding vehicle to the passage of the front end of the host vehicle at a certain point, and the stop inter-vehicle distance is the stop of the preceding vehicle and the host vehicle that are running. This is the distance between vehicles required for safety.

  According to the above configuration, the inter-vehicle time, the stop inter-vehicle distance, and the ratio are set in advance, and the reference inter-vehicle distance and the extended inter-vehicle distance are obtained simply by sequentially acquiring the detected vehicle speed and the detected inter-vehicle distance while the host vehicle is traveling. Therefore, it is possible to improve the fuel consumption rate with a very simple configuration and processing.

  According to the present invention, when the inter-vehicle distance exceeds the reference inter-vehicle distance, excessive follow-up traveling with respect to the preceding vehicle is suppressed, so that the fuel consumption rate can be improved.

It is a block diagram which shows the principal part of the vehicle provided with the inter-vehicle distance control apparatus which concerns on embodiment of this invention. It is a flowchart which shows the inter-vehicle distance control process which concerns on this invention. It is a flowchart which shows the target inter-vehicle distance setting process which concerns on this invention.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram illustrating a main part of a vehicle including an inter-vehicle distance control device according to an embodiment of the present invention, FIG. 2 is a flowchart illustrating inter-vehicle distance control processing executed by the inter-vehicle distance control device, and FIG. 3 is a target inter-vehicle distance. It is a flowchart explaining a distance setting process.

  As shown in FIG. 1, the vehicle 1 of this embodiment includes a radar sensor 2, a vehicle speed sensor 3, an ECU (Electric Control Unit) 4, an engine actuator 5, a brake actuator 6, and an inter-vehicle distance control switch 7. The radar sensor 2 constitutes an inter-vehicle distance detection means, and the vehicle speed sensor 3 constitutes a speed detection means.

  The radar sensor 2 transmits an electromagnetic wave such as a laser or a millimeter wave at a predetermined time from a front end portion of the vehicle 1 within a predetermined angle range in the traveling direction, and receives a reflected wave thereof. The detected inter-vehicle distance Da (m) and the relative speed with respect to 1 are detected, and the detected detected inter-vehicle distance Da and the relative speed are output to the ECU 4. The vehicle speed sensor 3 detects a detected vehicle speed V (m / s) as travel state information of the vehicle 1 at predetermined time intervals and outputs it to the ECU 4.

  The ECU 4 includes a CPU (Central Processing Unit) 41, a ROM (Read Only Memory) 42, and a RAM (Random Access Memory) 43. The CPU 41 functions as a target inter-vehicle distance setting unit and an acceleration / deceleration control unit by reading the program stored in the ROM 42 and executing the inter-vehicle distance control process. The RAM 43 has an area for appropriately storing the detection data of each sensor read by the CPU 41, the reference inter-vehicle distance Ds (m) and the target inter-vehicle distance Dr (m) calculated by the CPU 41. In addition, the RAM 43 stores in advance an inter-vehicle time Th (s), a stop inter-vehicle distance D0 (m), and a coefficient k (0 <k <1) as a predetermined ratio.

  The engine actuator 5 accelerates the vehicle 1 by opening an engine throttle (not shown) or controlling the fuel injection amount in accordance with an acceleration control signal from the ECU 4. The brake actuator 6 decelerates the vehicle 1 by operating disc brakes or drum brakes of front wheels and rear wheels (not shown) according to a deceleration control signal from the ECU 4. The inter-vehicle distance control switch 7 outputs an execution instruction signal for the inter-vehicle distance control process to the ECU 4 in response to an ON operation from the driver.

  Next, the inter-vehicle distance control process executed by the ECU 4 will be described based on the flowchart of FIG. This process is executed at predetermined time intervals on the condition that the vehicle 1 is traveling and has received an execution instruction signal from the inter-vehicle distance control switch 7.

  When this process is started, the ECU 4 acquires the inter-vehicle distance Da and the relative speed detected by the radar sensor 2 and the vehicle speed V detected by the vehicle speed sensor 3 (step S1).

  Next, the ECU 4 executes a target inter-vehicle distance setting process (step S2). In this process, the ECU 4 calculates the reference inter-vehicle distance Ds, and calculates the target inter-vehicle distance Dr from the detected inter-vehicle distance Da acquired in step 1 and the reference inter-vehicle distance Ds.

Next, the ECU 4 executes an acceleration / deceleration control process (step S3). In this process, the ECU 4 performs acceleration / deceleration control of the vehicle 1 based on the detected inter-vehicle distance Da acquired in step 1 and the target inter-vehicle distance Dr calculated in step S2. For example, in the case where the detected inter-vehicle distance Da exceeds the target inter-vehicle distance Dr and shows an increasing tendency (when the vehicle 1 tries to leave the preceding vehicle due to acceleration of the preceding vehicle), the engine actuator is controlled to control the vehicle 1 is accelerated, and the detected inter-vehicle distance Da is converged to the target inter-vehicle distance Dr. Further, when the detected inter-vehicle distance Da indicates decreasing trend in the state of less than the target inter-vehicle distance D r (if the vehicle 1 by the reduction of the preceding vehicle is going to approach the preceding vehicle) is a vehicle 1 by controlling the brake actuator Decelerate.

  Next, the details of the target inter-vehicle distance setting process will be described based on the flowchart of FIG.

  In this process, the ECU 4 uses the following inter-vehicle distance Ds as the following equation (1) using the pre-stored inter-vehicle time Th and stop inter-vehicle distance D0 and the vehicle speed V acquired in step S1 (see FIG. 2). Calculate (step S21).

  Ds = Th × V + D0 (1)

  Next, the ECU 4 determines whether or not the detected inter-vehicle distance Da acquired in step S1 exceeds the calculated reference inter-vehicle distance Ds (step S22). When it is determined that the detected inter-vehicle distance Da is equal to or less than the reference inter-vehicle distance Ds (step S22: NO), the ECU 4 updates and stores the reference inter-vehicle distance Ds in the RAM 43 as the target inter-vehicle distance Dr (step S23). End and proceed to step S3 (see FIG. 2).

  On the other hand, when it is determined that the detected inter-vehicle distance Da exceeds the reference inter-vehicle distance Ds (step S22: YES), the process proceeds to step S24, where the ECU 4 sets the extended inter-vehicle distance De (m) to a previously stored coefficient k, Calculation is performed according to the following equation (2) using the inter-vehicle time Th and the stop inter-vehicle distance D0, the vehicle speed V acquired in step S1 (see FIG. 2), and the detected inter-vehicle distance Da.

  De = (1-k) × (Th × V + D0) + k × Da (2)

  Subsequently, the ECU 4 updates and stores the calculated extended inter-vehicle distance De as the target inter-vehicle distance Dr (step S25), ends the present process, and proceeds to step S3 (see FIG. 2).

  In addition, when the right side of the above equation (2) is expanded and summarized, the following equation (3) is obtained, and the following equation (4) is obtained from the following equation (3) and the above equation (1).

De = Th × V + D0 + k × (Da− (Th × V + D0)) (3)
De−Ds = k × (Da−Ds) (4)

  As apparent from the above equation (4), the extended inter-vehicle distance De is longer than the reference inter-vehicle distance Ds by a distance obtained by multiplying the difference between the detected inter-vehicle distance Da and the reference inter-vehicle distance Ds by a coefficient k.

  According to the present embodiment, for example, when the preceding vehicle decelerates in a situation where the vehicle 1 follows the vehicle 1 while maintaining the target inter-vehicle distance Dr with the preceding vehicle, the vehicle 1 sets the reference inter-vehicle distance Ds. Decelerate as the target inter-vehicle distance Dr. On the other hand, when the preceding vehicle accelerates, the vehicle 1 accelerates using the extended inter-vehicle distance De that is longer than the reference inter-vehicle distance Ds as the target inter-vehicle distance Dr. That is, the rear-end collision of the vehicle 1 with the preceding vehicle that decelerates is avoided by setting the reference inter-vehicle distance Ds as the target inter-vehicle distance Dr. In addition, following the accelerating preceding vehicle is mitigated as compared with the case where the reference inter-vehicle distance Ds is set as the target inter-vehicle distance Dr by setting the extended inter-vehicle distance De longer than the reference inter-vehicle distance Ds as the target inter-vehicle distance Dr. . In particular, the extended inter-vehicle distance De increases / decreases depending on the difference between the detected inter-vehicle distance Da and the reference inter-vehicle distance Ds, so that excessive follow-up traveling is reduced according to the magnitude of the acceleration of the preceding vehicle. Therefore, deterioration of the fuel consumption rate of the vehicle 1 is prevented.

  Further, since the detected inter-vehicle distance Da can be calculated as a time integral value of the relative speed between the vehicle 1 and the preceding vehicle, it can be regarded as a time history of the relative speed between the vehicle 1 and the preceding vehicle. Therefore, the extended inter-vehicle distance De taking into account the time history of the relative speed between the vehicle 1 and the preceding vehicle can be used as the target inter-vehicle distance Dr when the detected inter-vehicle distance Da exceeds the reference inter-vehicle distance Ds.

Furthermore, only sequentially obtains the detection inter-vehicle distance Da and the vehicle speed V during running of the vehicle 1, since the a reference inter-vehicle distance Ds and extended inter-vehicle distance D e can be calculated, the fuel by the extremely simple configuration and processing The consumption rate can be improved.

  As mentioned above, although the embodiment to which the invention made by the present inventor is applied has been described, the present invention is not limited by the discussion and the drawings that form part of the disclosure of the present invention according to this embodiment. That is, it is needless to say that other embodiments, examples, operation techniques, and the like made by those skilled in the art based on this embodiment are all included in the scope of the present invention.

  For example, in the above embodiment, the radar sensor 2 detects the detected inter-vehicle distance Da and the relative speed. However, the radar sensor 2 detects only the detected inter-vehicle distance Da, and the ECU 4 determines the relative speed from the time change of the detected inter-vehicle distance Da. It is good also as a structure which calculates.

  Further, in the above embodiment, the coefficient k is set in advance as one fixed value. However, a plurality of different coefficients k are set in advance, and the driver of the vehicle 1 can select a plurality of coefficients k depending on the driving situation. Further, the ECU 4 may be configured so that a desired one can be selected, and the ECU 4 selects one of a plurality of coefficients k according to the state of the vehicle 1 (for example, the detected inter-vehicle distance Da and the reference inter-vehicle distance Ds). You may comprise so that it may select and determine. Further, the coefficient k may be obtained by calculation according to the state of the vehicle 1.

  In the above embodiment, one ECU 4 executes the target inter-vehicle distance setting process and the acceleration / deceleration control process. However, the processing apparatus that executes the target inter-vehicle distance setting process and the processing apparatus that executes the acceleration / deceleration control process; May be configured as different units. Therefore, for an existing vehicle equipped with a device that executes acceleration / deceleration control processing according to the target inter-vehicle distance Dr, a device (unit) that performs target inter-vehicle distance setting processing may be additionally installed. The present invention can be easily applied to such an existing vehicle to improve the fuel consumption rate.

  The present invention can be widely applied to an inter-vehicle distance control device that causes a vehicle to follow a preceding vehicle.

1: Vehicle (own vehicle)
2: Radar sensor (vehicle distance detection means)
3: Vehicle speed sensor (speed detection means)
4: ECU (target inter-vehicle distance setting means, acceleration / deceleration control means)
5: Engine actuator
6: Brake actuator
7: Inter-vehicle distance control switch Da: Detected inter-vehicle distance Ds: Reference inter-vehicle distance Dr: Target inter-vehicle distance De: Extended inter-vehicle distance D0: Stop inter-vehicle distance Th: Inter-vehicle time V: Vehicle speed k: Coefficient (ratio)

Claims (2)

An inter-vehicle distance detecting means for detecting an inter-vehicle distance between the preceding vehicle and the host vehicle;
Speed detecting means for detecting the speed of the host vehicle;
A reference inter-vehicle distance is obtained based on the speed detected by the speed detection means, and when the inter-vehicle distance detected by the inter-vehicle distance detection means is equal to or less than the reference inter-vehicle distance, the reference inter-vehicle distance is set as a target inter-vehicle distance, When the inter-vehicle distance detected by the inter-vehicle distance detection means exceeds the reference inter-vehicle distance, the reference inter-vehicle distance is obtained by adding the reference inter- vehicle distance and the inter-vehicle distance detected by the inter-vehicle distance detection means at a predetermined ratio. A target inter-vehicle distance setting means for setting a long extended inter-vehicle distance as a target inter-vehicle distance,
An inter-vehicle distance control device comprising: an acceleration / deceleration control unit that controls acceleration / deceleration of the host vehicle so that the inter-vehicle distance detected by the inter-vehicle distance detection unit approaches the target inter-vehicle distance. The inter-vehicle distance control device according to claim 1,
The target inter-vehicle distance setting means obtains a reference inter-vehicle distance by adding a distance obtained by multiplying a speed detected by the speed detecting means by a predetermined inter-vehicle time and a predetermined stop inter- vehicle distance. .

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