JPH0631600Y2 - Inter-vehicle distance control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] This invention calculates acceleration / deceleration of a vehicle in front or an obstacle,
The present invention relates to an inter-vehicle distance control device that changes a target inter-vehicle distance according to the acceleration / deceleration.

[Prior Art] Conventionally, an inter-vehicle distance control device for keeping an inter-vehicle distance at a predetermined value has been proposed (see Japanese Patent Laid-Open No. 61-77534), but in this one, a braking means (hereinafter referred to as a brake) is used. ), A vehicle traveling forward using the output of the engine (throttle valve opening) or a transmission gear (hereinafter referred to as the preceding vehicle)
A predetermined distance corresponding to the vehicle speed is maintained as the vehicle-to-vehicle distance.

Further, as disclosed in Japanese Patent Application Laid-Open No. 62-23832, the fact that the vehicle (hereinafter referred to as the own vehicle) is decelerating is notified, the difference between the inter-vehicle distance and the target inter-vehicle distance, and the change rate of the inter-vehicle distance. There is an inter-vehicle distance control device that gives an advance notice of the increase / decrease of the vehicle speed based on.

[Problems to be Solved by the Invention] By the way, in any of the inter-vehicle distance control devices described above, when a sudden traveling change occurs due to acceleration / deceleration of the preceding vehicle, the change in the inter-vehicle distance changes with respect to the traveling change of the preceding vehicle. Since it changes with a delay, there is a problem in that the control of the own vehicle using this delays and the followability of the own vehicle is poor.

The present invention has been made to solve the above-described problems, and an object thereof is to obtain an inter-vehicle distance control device that can improve the following performance and safety by changing the target inter-vehicle distance according to the acceleration / deceleration of the preceding vehicle. To do.

[Means for Solving the Problems] An inter-vehicle distance control device according to the present invention drives a throttle valve, a distance measuring means for measuring an inter-vehicle distance between an own vehicle and a vehicle in front, a braking means for braking the own vehicle, and a throttle valve. A throttle valve driving means, a vehicle speed measuring means for measuring the traveling speed of the own vehicle,
Acceleration / deceleration calculation means for calculating the acceleration / deceleration of the front vehicle from the inter-vehicle distance and the own vehicle traveling speed, and setting the target inter-vehicle distance based on the inter-vehicle distance, the own vehicle traveling speed and the acceleration / deceleration of the preceding vehicle, And a control means for controlling the braking means or the throttle valve driving means so that the distance measured by the inter-vehicle distance becomes equal to the target inter-vehicle distance.

[Operation] According to the device of the present invention configured as described above, when the vehicle or obstacle in front accelerates or decelerates, the acceleration / deceleration calculating means first determines the distance from the output of the distance measuring means and the output of the vehicle speed measuring means. Calculate the acceleration / deceleration of the vehicle or obstacle.

Then, based on the acceleration / deceleration, the inter-vehicle distance, and the traveling speed of the host vehicle, separate calculation processing is performed when the preceding vehicle is in the steady traveling state and when the preceding vehicle is in the accelerating / decelerating state, and the target optimal inter-vehicle distance is calculated. Ask. Then, the braking means or the throttle valve driving means is controlled so that the current distance measured by the distance measuring means becomes equal to the target inter-vehicle distance.

Therefore, the followability when the vehicle ahead accelerates or decelerates is improved, and further safety is secured.

[Embodiment] A preferred embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention. An inter-vehicle distance control device 10 is provided for a vehicle driven by an engine.
Is mounted, and the control device 10 includes an arithmetic processing circuit 12 as a control means configured by a microcomputer or the like.

Then, the output of the distance measuring device 14 for measuring the inter-vehicle distance D between the preceding vehicle or the obstacle and the output of the vehicle speed measuring device 16 for measuring the speed V of the own vehicle are input to the arithmetic processing circuit 12. There is.

Further, a braking device 20 for frictionally braking a wheel is connected to the arithmetic processing circuit 12, and the braking device 20 can be controlled by a signal from the arithmetic processing circuit 12. The driver can also operate the pedal directly.

A throttle valve drive device 22 for driving a throttle valve of the engine is connected to the arithmetic processing circuit 12, and the throttle valve drive device valve 22 is connected to the arithmetic processing circuit 12
Further, the driving device 22 can be directly operated by the driver by an accelerator pedal.

Next, the operation of this embodiment will be described with reference to the flowchart of FIG.

In step 1, the arithmetic processing circuit 12 inputs the output of the distance measuring device 14 and calculates the current inter-vehicle distance D from the preceding vehicle.

Then, the arithmetic processing circuit 12 which receives the output from the vehicle speed measuring device 16 calculates the vehicle speed V of the own vehicle (step S2). Further, the arithmetic processing circuit 12 obtains the acceleration / deceleration g of the own vehicle by differentiating the vehicle speed V with respect to time (step S).
3).

Then, the arithmetic processing circuit 12 calculates the vehicle speed V ₀ of the preceding vehicle by the expression 100 (step S4). Further, the arithmetic processing circuit 12 uses a first
The acceleration / deceleration g ₀ of the preceding vehicle is calculated by the expression 01 (step S5). That is, Since dV ₀ / dt = g ₀ and dV / dt = g, the 101st equation is Can be displayed as Ask for.

Then, the arithmetic processing circuit 12 determines whether or not the preceding vehicle is in the acceleration / deceleration state on the basis of the calculated acceleration / deceleration g ₀ of the preceding vehicle (step S6). A target inter-vehicle distance during steady traveling, which is determined by the time change rate of the distance D, is calculated (step S7) (see FIG. 3).

Then, the arithmetic processing circuit 12 calculates the target torque, that is, the steady torque F ₀ due to the running resistance, the road inclination, etc. (step S8).

Further, the arithmetic processing circuit 12 calculates a difference ΔF between the calculated torque F ₀ and the target torque calculated one step before (step S9), and when ΔF = 0, returns to step S1 (step S10).

Then, when ΔF ≠ 0, the arithmetic processing circuit 12 determines ΔF>
When it is determined that it is 0 (step S11), and when it is determined that ΔF> 0, a control signal is sent to the throttle valve drive device 22 to accelerate it (step S12). When it is determined that ΔF <0, it is an arithmetic processing circuit. 12 sends a control signal to the braking device 20 to brake and decelerate (step S13).

On the other hand, when it is determined in step S6 that the vehicle is in the acceleration / deceleration state, the arithmetic processing circuit 12 calculates the target inter-vehicle distance at the time of acceleration / deceleration by the expression 103 (step S1).
4).

= + Αg ₀ (103) where α is a control gain.

Further, the arithmetic processing circuit 12 calculates the target torque F at the time of acceleration / deceleration by the expression 104 (step S15).

F = K ₁ (D −) + K ₂ (V−V ₀ ) + F ₀ (104) Note that K ₁ and K ₂ are control gains.

Hereinafter, steady running or acceleration / deceleration is performed by the same operation after step S9.

In addition, by adding an own vehicle acceleration / deceleration measuring device that directly measures the acceleration / deceleration of the own vehicle to the device of the present invention, it is possible to detect changes in the running state of the own vehicle, causing the preceding vehicle to change suddenly. In this case, by changing the correction method according to the acceleration state and the deceleration state of the host vehicle, control with better followability becomes possible.

[Advantages of the Invention] As described above, according to the present invention, the target inter-vehicle distance is changed according to the acceleration / deceleration state of the preceding vehicle, so that the followability can be improved and the driving feeling can be improved. You can
Further, even if an unexpected situation such as a sudden stop during acceleration or deceleration of the preceding vehicle occurs, the time margin for dealing with the situation increases and the safety improves.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2 is a flow chart for explaining the operation of the embodiment of FIG. 1, and FIG. 3 is a diagram showing a relationship between a target inter-vehicle distance and a vehicle speed. Is. 10 ... Inter-vehicle distance control device 12 ... Control means 14 ... Distance measuring means 16 ... Vehicle speed measuring means 18 ... Acceleration / deceleration measuring means 20 ... Braking means 22 ... Throttle valve driving means

Claims (1)

[Scope of utility model registration request] 1. A distance measuring means for measuring a distance between an own vehicle and a vehicle ahead, a braking means for braking the own vehicle, a throttle valve driving means for driving a throttle valve, and a traveling speed of the own vehicle. A vehicle speed measuring means, an acceleration / deceleration calculating means for calculating an acceleration / deceleration of a front vehicle from the inter-vehicle distance and the own vehicle traveling speed, and a target based on the inter-vehicle distance, the own vehicle traveling speed and an acceleration / deceleration of the preceding vehicle. An inter-vehicle distance control device, comprising: a control means for setting a vehicle-to-vehicle distance and controlling the braking means or the throttle valve driving means so that the distance measured by the vehicle-to-vehicle distance becomes equal to the target vehicle-to-vehicle distance.