JP2005335550A - Vehicle speed control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle speed control device capable of changing the degree of control by the relative traveling condition of a preceding vehicle traveling before an own vehicle to the own vehicle. <P>SOLUTION: The vehicle speed control device comprises operational condition detection means (2, 3) to detect the operational condition of a vehicle, a target vehicle speed setting means (30) to set the target vehicle speed of an own vehicle based on the operational condition, an actual vehicle speed detection means (4) to detect the actual vehicle speed of the own vehicle, vehicle speed control means (40, 50, 60) to perform the control so that the actual vehicle speed is matched with the target vehicle speed by feeding back the actual vehicle speed, a traveling condition detection means (9) to detect the relative traveling condition of the own vehicle to a preceding vehicle traveling before the own vehicle, a control gain correction means (70) to correct the control gain of the vehicle speed control means based on the relative traveling condition of the own vehicle to the preceding vehicle. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vehicle speed control device that controls a vehicle to a vehicle speed intended by a driver.

  Various vehicle speed control devices that control the vehicle speed by controlling the throttle opening, the gear ratio, etc. based on the vehicle speed command signal have been proposed for the purpose of reducing the burden on the driver.

For example, in Patent Document 1, the target acceleration or target deceleration is obtained from the accelerator opening, and the valve opening of the throttle valve is controlled so that the target acceleration / deceleration can be achieved. Next, the actual vehicle speed is detected by the vehicle speed sensor, and the actual acceleration / deceleration is obtained by differentiating the vehicle speed. Then, it is determined whether or not the target acceleration / deceleration and the actual acceleration / deceleration match, and if they do not match, the response of the vehicle acceleration to the depression of the accelerator is improved by correcting the valve opening. .
JP 2000-205015 A

  However, the above-described conventional vehicle speed control device simply determines whether or not the target acceleration / deceleration matches the actual acceleration / deceleration, and if not, corrects the valve opening to depress the accelerator pedal. Since the response of the vehicle acceleration to the vehicle is enhanced, an excessive correction may be made depending on the driving scene.

  That is, for example, when the inter-vehicle distance from the preceding vehicle traveling ahead is likely to become a little more appropriate distance, the driver may step on the accelerator and try to approach. Further, when the distance between the preceding vehicle and the preceding vehicle is an appropriate distance, there is a possibility that the accelerator will be stepped on too much due to a driver's operation mistake or the like. In such a case, if the response of the vehicle acceleration to the depression of the accelerator pedal is increased too much, the own vehicle may be too close to the preceding vehicle.

Vehicles with high vehicle acceleration responsiveness to accelerator pedal depression are often preferred by drivers as being responsive.
However, such control always has the possibility of increasing the driver's fatigue instead of the vehicle speed control device originally intended to reduce the burden on the driver.

  The present invention has been made paying attention to such conventional problems, and a vehicle speed control device that changes the degree of control according to the relative traveling state of a preceding vehicle traveling in front of the own vehicle and the own vehicle. The purpose is to provide.

  The present invention solves the above problems by the following means. In addition, in order to make an understanding easy, although the code | symbol corresponding to embodiment of this invention is attached | subjected, it is not limited to this.

  The present invention includes operation state detection means (2, 3) for detecting an operation state of a vehicle, target vehicle speed setting means (30) for setting a target vehicle speed of the own vehicle based on the operation state, and an actual vehicle of the own vehicle. An actual vehicle speed detecting means (4) for detecting the speed, a vehicle speed control means (40, 50, 60) for controlling the actual vehicle speed so as to coincide with the target vehicle speed by feeding back the actual vehicle speed; A vehicle state control means (9) for detecting a relative traveling state between the preceding vehicle traveling on the vehicle and the host vehicle, and control of the vehicle speed control unit based on a relative traveling state of the host vehicle with respect to the preceding vehicle. And a control gain correction means (70) for correcting the gain.

  According to the present invention, the relative traveling state between the preceding vehicle traveling in front of the host vehicle and the host vehicle is detected, and the control gain of the vehicle speed control means is corrected based on the detected traveling state. Therefore, when there is no preceding vehicle, it is possible to increase the response of the vehicle acceleration to the depression of the accelerator pedal, and when there is a preceding vehicle, when the accelerator is stepped too much due to a driver's operation mistake etc. Even so, it is possible to prevent the vehicle from approaching the vehicle ahead.

Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings.
(First embodiment)
FIG. 1 is a diagram showing a system configuration showing a first embodiment of a vehicle speed control apparatus according to the present invention.

  The control start switch 1 detects whether or not to execute vehicle speed control. If the switch is on, it is determined that vehicle speed control is being executed. When the switch is off, the vehicle speed control is stopped.

  The brake switch 2 detects whether or not the driver is stepping on the brake. When the brake is depressed, it is turned on. When the brake is released, it is turned off.

  The inter-vehicle distance sensor 9 uses a laser or a radio wave, and detects an inter-vehicle distance La and a relative speed detection value Vt from a preceding vehicle from a reflected wave.

  The accelerator opening sensor 3 detects the accelerator depression amount APO of the driver.

  The vehicle speed sensor 4 detects the actual vehicle speed aVSP of the vehicle from the rotational speed of the tire.

  The engine speed sensor 5 detects the engine speed aNE from the engine ignition signal.

  The vehicle speed control ECU 10 is composed of a microcomputer and its peripheral components. The control start switch 1, brake switch 2, accelerator opening sensor 3, vehicle speed sensor 4, engine rotation speed sensor 5, inter-vehicle distance are provided every control cycle (for example, 10 ms). A signal from the sensor 9 is taken in and a command value is output to the engine ECU 6 and the transmission ECU 7. As shown in FIG. 1, the vehicle speed control ECU 10 includes a control start determination unit 20, a target vehicle speed calculation unit 30, a vehicle speed control unit 40, an actual gear ratio calculation unit 50, and a driving force distribution unit 60 configured in the form of a microcomputer software. The control gain correction value calculation unit 70 is provided.

  The vehicle speed control ECU 10 controls the vehicle speed by using a throttle and a transmission.

  The engine ECU 6 calculates the throttle opening based on the engine torque command value cTE output from the vehicle speed control ECU 10 and the control execution flag fSTART, and outputs a throttle opening signal to the throttle actuator 8. That is, when the control execution flag fSTART is 1, the engine ECU 6 determines that the vehicle speed control is being executed, and causes the throttle actuator 8 to output the engine torque based on the engine torque command value cTE output from the vehicle speed control ECU 10. Control. On the other hand, when the control execution flag fSTART is 0, it is determined that the vehicle speed control is stopped, and the throttle actuator 8 is controlled so as to output the engine torque corresponding to the accelerator depression amount APO.

  The throttle actuator 8 adjusts the throttle valve of the engine according to the throttle opening signal.

  The transmission ECU 7 adjusts the transmission gear ratio based on the gear ratio command value cRATIO and the control execution flag fSTART output from the vehicle speed control ECU 10. That is, when the control execution flag fSTART is 1, the transmission ECU 7 determines that the vehicle speed control is being executed, and sets the speed ratio to the speed ratio command value cRATIO output from the vehicle speed control ECU 10. On the other hand, when the control execution flag fSTART is 0, it is determined that the vehicle speed control is stopped, and a gear ratio is set according to the accelerator depression amount APO and the actual vehicle speed aVSP.

Next, each component of the vehicle speed control ECU 10 will be described in detail.
<< Control start determination unit 20 >>
The operation of the control start determination unit 20 will be described based on the flowchart shown in FIG.

  In step 1 (abbreviated as “S1” in the figure, the same applies hereinafter), a signal from the control start switch 1 is taken to determine whether the switch is on or off. If it is in the on state, the process proceeds to step 2. If it is in the off state, the process proceeds to step 4.

  In step 2, a signal from the brake switch 2 is captured to determine whether the brake switch is in an on state or an off state. If it is in the on state, the process proceeds to step 4, and if it is in the off state, the process proceeds to step 3.

  In step 3, the control execution flag fSTART is set to 1.

  In step 4, the control execution flag fSTART is set to 0, and vehicle speed control stop processing is performed. For example, when the driver is stepping on the brake, the vehicle speed control stop process is performed with the flag fSTART set to 0 because the target vehicle speed tVSP cannot be made to follow the target vehicle speed tVSP with the throttle opening and the gear ratio.

  The control execution flag fSTART output from the control start determination unit 20 is input to the engine ECU 6 and the transmission ECU 7, and the engine ECU 6 and the transmission ECU 7 perform the control as described above.

≪Target vehicle speed calculation unit 30≫
As shown in FIG. 3, the target vehicle speed calculation unit 30 includes a target acceleration determination unit 31 and an integration processing unit 32. The target vehicle speed calculation unit 30 takes in a control execution flag fSTART, an actual vehicle speed aVSP, and an accelerator depression amount APO, and calculates a target vehicle speed tVSP.

  The target acceleration determining unit 31 determines the target acceleration tACC based on the map shown in FIG. 4 from the accelerator depression amount APO and the target vehicle speed tVSP calculated by the integration processing unit 32. As shown in FIG. 4, the target acceleration tACC increases as the accelerator depression amount increases. Further, in order to cope with the fact that the higher the vehicle speed, the greater the running resistance and the lower the realizable acceleration, in FIG. 4, the target acceleration is set to become smaller as the vehicle speed increases for the same accelerator depression amount. Yes.

  The integration processing unit 32 calculates the target vehicle speed tVSP based on the control execution flag fSTART, the actual vehicle speed aVSP, and the target acceleration tACC. Here, the processing content of the integration processing unit 32 will be described with reference to FIG. When the control execution flag fSTART is 0, that is, when the control start switch 1 is in the off state or the brake is depressed, the target vehicle speed tVSP and the previous value of tVSP are initialized with the actual vehicle speed aVSP (step 7). When the control execution flag fSTART is 1, that is, when the control start switch 1 is on and the brake is not depressed, the target vehicle speed tVSP is obtained by adding the target acceleration tACC to the previous value of tVSP. After calculating the target vehicle speed tVSP, the previous value of tVSP is updated with the target vehicle speed tVSP (step 6). The target vehicle speed tVSP is output to the vehicle speed control unit 40.

<< Control Gain Correction Value Calculation Unit 70 >>
The control gain correction value calculation unit 70 takes in the inter-vehicle distance La to the vehicle traveling ahead and the relative speed Vt (= the vehicle speed of the preceding vehicle−the vehicle speed of the host vehicle), and calculates the differential control gain correction value α. Specifically, the differential control gain correction value is tabulated from the map shown in FIG.

The control gain correction value α is set based on the correction value α _L obtained from the inter-vehicle distance La using the map (a) and the correction value α _V obtained from the relative speed Vt using the map (b). Alternatively, only one of them may be used as the control gain correction value α.

  For example, the following formulas (1) to (4) may be used based on the map shown in FIG.

≪車速制御部４０≫
図７に車速制御部４０の構成を示す。車速制御部４０はフィードフォワード制御部（以下Ｆ／Ｆ制御部と略す）とフィードバック制御部（以下Ｆ／Ｂ制御部と略す）からなる２自由度制御系で構成されている。車速制御部４０は、目標車速tVSPを入力とし出力を自車速aVSPとした場合の伝達特性が図７の規範モデル４２の伝達特性となるようにＦ／Ｆ制御部とＦ／Ｂ制御部を用いて制御を行う。規範モデル４２の伝達関数Ｇ_T(s)は、次式で表される。

≪Vehicle speed control unit 40≫
FIG. 7 shows the configuration of the vehicle speed control unit 40. The vehicle speed control unit 40 includes a two-degree-of-freedom control system including a feedforward control unit (hereinafter abbreviated as F / F control unit) and a feedback control unit (hereinafter abbreviated as F / B control unit). The vehicle speed control unit 40 uses the F / F control unit and the F / B control unit so that the transfer characteristic when the target vehicle speed tVSP is input and the output is the own vehicle speed aVSP is the transfer characteristic of the reference model 42 in FIG. Control. The transfer function G _T (s) of the reference model 42 is expressed by the following equation.

すなわち、規範モデル４２の伝達関数Ｇ_T(s)は時定数τ_Hの１次のローパスフィルタと無駄時間Ｌ_Vからなる。ここでｓはラプラス演算子を表す。

That is, the transfer function G _T (s) dead time and first-order low-pass filter time constant tau _H is L _V of the reference model 42. Here, s represents a Laplace operator.

  The vehicle model to be controlled is modeled using the drive torque command value as the manipulated variable and the vehicle speed as the controlled variable, so that the behavior of the vehicle's powertrain can be expressed by the simple nonlinear model shown in FIG. expressed.

駆動トルク指令値を入力とし、車速を出力とする車両モデルは積分特性となる。ただし、制御対象の特性にはパワートレイン系の遅れにより無駄時間も含まれることになり、使用するアクチュエータやエンジンによって無駄時間Ｌ_Pは変化する。

A vehicle model having the drive torque command value as input and the vehicle speed as output has integral characteristics. However, the characteristics to be controlled include a dead time due to the delay of the power train system, and the dead time L _P varies depending on the actuator and engine used.

The F / F control unit includes a phase compensator 41 as shown in FIG. 7, and the F / F command value predetermines response characteristics of a control target when the target vehicle speed tVSP is input and the actual vehicle speed aVSP is output. Furthermore, it is made to coincide with the characteristic of a predetermined transfer characteristic G _T (s) having a first order delay and a dead time element. If the dead time of the control target is ignored and the transfer characteristic G _T (s) of the reference model 42 is a first-order low-pass filter with a time constant τ _H , the transfer characteristic G _C (s) of the phase compensator 41 is It is expressed by a formula.

Ｆ／Ｂ制御部は図７に示すように規範モデル４２とフィードバック補償器４３より構成される。規範モデル４２から出力される規範応答Vrefと自車速aVSPとの差をフィードバック補償器４３の入力とし、Ｆ／Ｂ指令値を算出する。Ｆ／Ｂ指令値により外乱やモデル化誤差による影響を抑える。

The F / B control unit includes a reference model 42 and a feedback compensator 43 as shown in FIG. The difference between the reference response Vref output from the reference model 42 and the own vehicle speed aVSP is input to the feedback compensator 43, and the F / B command value is calculated. The F / B command value suppresses the influence of disturbances and modeling errors.

  As the feedback compensator, a PD compensator is used as shown in FIG. The proportional control gain Kp uses a preset value, and the differential control gain Kd uses the differential control gain Dgain calculated by the control gain correction value calculation unit 70 as the differential control gain Dgain set in advance. Multiply to find. That is, the differential control gain Kd is obtained by the following equation.

Kd = Dgain · α
The drive torque conversion unit 44 applies a value obtained by adding the F / B command value calculated by the F / B compensator 43 to the F / F command value calculated by the phase compensator (F / F control unit) 41. A drive torque command value cTDR is calculated by multiplying the vehicle mass M and the tire moving radius Rt.

≪Actual gear ratio calculation unit 50≫
The actual speed ratio calculating unit 50 in FIG. 1 calculates the actual speed ratio aRATIO according to the following equation from the host vehicle speed aVSP and the engine speed aNE.

≪駆動力分配部６０≫
駆動力分配部６０について図９をもとに説明する。駆動力分配部６０では、車速aVSP、駆動トルク指令値cTDR、実変速比aRATIOを入力として変速比指令値cRATIOとエンジントルク指令値cTEを算出する。

≪Driving force distribution unit 60≫
The driving force distribution unit 60 will be described with reference to FIG. The driving force distribution unit 60 receives the vehicle speed aVSP, the driving torque command value cTDR, and the actual gear ratio aRATIO as input, and calculates the gear ratio command value cRATIO and the engine torque command value cTE.

  The gear ratio command value cRATIO is calculated by the gear ratio command value setting unit 61. The gear ratio command value setting unit 61 determines the gear ratio command value cRATIO from the drive torque command value cTDR and the host vehicle speed aVSP using the map shown in FIG. FIG. 10 shows a map when a continuously variable transmission is used.

  The engine torque command value calculation unit 62 calculates an engine torque command value cTE from the drive torque command value cTDR and the actual gear ratio aRATIO according to the following equation.

駆動力分配部６０にて算出された変速比指令値cRATIOは、図１に示される通り、トランスミッションＥＣＵ７へ出力される。エンジントルク指令値cTEは、エンジンＥＣＵ６へ出力される。

The gear ratio command value cRATIO calculated by the driving force distribution unit 60 is output to the transmission ECU 7 as shown in FIG. The engine torque command value cTE is output to the engine ECU 6.

  The configuration of the vehicle speed control device according to the present invention is as described above. Next, the effects will be described.

  FIG. 11 is a diagram illustrating a difference in response of the actual vehicle speed to the target vehicle speed for each F / B control method of the vehicle speed control unit.

  FIG. 11A shows the response of the actual vehicle speed for each control when the target vehicle speed changes from V0 to V1 at times t0 to t1. Pattern A is a case where only proportional control is performed. Pattern B is a case where proportional control and differential control are performed. Pattern C is a case where proportional control and differential control are performed, and the differential control is slightly weakened.

  FIG. 11B shows a change in the acceleration command value in the pattern A. As is apparent from FIG. 11B, when only the proportional control is performed, when the target vehicle speed changes from V0 to V1, the acceleration command value also changes in accordance with the change (time after FIG. 11B). Until the target vehicle speed is reached (t0 to t1), the acceleration command value also changes with a constant gradient (time t1 to t4 in FIG. 11B). At this time, the actual vehicle speed hardly changes immediately after the target vehicle speed changes as indicated by the solid line in FIG. 11A (near time t0 to t1 in FIG. 11A), and the actual vehicle speed matches the target vehicle speed. It is time t4 and is delayed compared to other patterns.

  FIG. 11C shows a change in the acceleration command value in the pattern B. As is apparent from FIG. 11C, when proportional control and differential control are performed, if the target vehicle speed changes from V0 to V1, the acceleration command value changes greatly at the start of the change (FIG. 11). At time t0 in (C), the acceleration command value also changes in accordance with the change in the target vehicle speed (time t0 to t1 in FIG. 11C). When the target vehicle speed becomes constant (time t1 in FIG. 11A), the acceleration command value also decreases (time t1 in FIG. 11C). Thereafter, the acceleration command value also has a constant gradient until the target vehicle speed is reached. (Time t1 to t2 in FIG. 11C). At this time, as shown by a broken line in FIG. 11A, the actual vehicle speed changes immediately after the target vehicle speed changes (near time t0 in FIG. 11A), and the actual vehicle speed matches the target vehicle speed. At time t2, it matches earlier than the other patterns.

  Thus, pattern B (broken line) is a case where proportional control + derivative control is performed on pattern A. In this case, since the influence of the differential control is strong at the moment when the target vehicle speed changes, the responsiveness of the vehicle at the moment when the accelerator is started, that is, the moment when the target vehicle speed changes can be improved.

  FIG. 11D shows a change in the acceleration command value in the pattern C. As is apparent from FIG. 11D, when the proportional control and the slightly weaker differential control are performed, if the target vehicle speed changes from V0 to V1, the acceleration command value changes at the start of the change ( At time t0 in FIG. 11D, the acceleration command value also changes in accordance with the change in the target vehicle speed (time t0 to t1 in FIG. 11D). When the target vehicle speed becomes constant (time t1 in FIG. 11A), the acceleration command value also decreases (time t1 in FIG. 11D), and thereafter, the acceleration command value also has a constant gradient until the target vehicle speed is reached. (Time t1 to t2 in FIG. 11D). At this time, the actual vehicle speed changes immediately after the target vehicle speed changes, as indicated by a two-dot broken line in FIG. 11A (near time t0 in FIG. 11A), and the actual vehicle speed matches the target vehicle speed. No. is a time t3, which is a characteristic between other patterns.

  As described above, the pattern C (two-dot chain line) is a case where only the gain of differential control is lowered (multiplied by 0.8) with respect to the pattern B. In this case, the response at the moment when the target vehicle speed changes is slightly suppressed. Therefore, the vehicle does not respond more sensitively to the driver's accelerator operation than pattern B.

  As is apparent from the above, by adjusting only the gain of the differential control, the responsiveness of the actual vehicle speed at the moment when the driver depresses the accelerator, that is, the moment when the target vehicle speed changes can be changed. In addition, the steady-state characteristics where the target vehicle speed is constant for all three patterns remain the same, so if the driver is steadily stepping on the accelerator, it can be accelerated as before, for example, overtaking performance, etc. Can obtain the same characteristics as in the prior art.

  12 and 13 show the vehicle behavior when approaching the preceding vehicle.

  FIG. 12 shows a case where proportional control and differential control are performed, but the gain of differential control is not particularly adjusted.

  Although the vehicle is approaching the vehicle ahead, there is still a sufficient inter-vehicle distance, so if the driver steps on the accelerator a little to reduce the inter-vehicle distance (time t11 to t12 in FIG. 12A), a certain vehicle Acceleration occurs (FIG. 12B), and the inter-vehicle distance is reduced (FIG. 12D).

  When the driver is about to reach an appropriate inter-vehicle distance (time t13), when the driver depresses the accelerator as before (Fig. 12 (A)), the vehicle accelerates with the same response as when the inter-vehicle distance is far away. In such a case (FIG. 12 (B)), there is a possibility that the space between the vehicles will be clogged more than necessary (FIG. 12 (D)).

  FIG. 13 shows a case where proportional control and differential control are performed and the gain of the differential control is adjusted in relation to the vehicle ahead.

  Although the vehicle is approaching the vehicle ahead, there is still a sufficient inter-vehicle distance, so when the driver steps on the accelerator a little to reduce the inter-vehicle distance (time t21 to t22 in FIG. 13A), a certain vehicle Acceleration occurs (FIG. 13B), and the inter-vehicle distance is reduced (FIG. 13D).

  When the vehicle distance is likely to become a little more appropriate (time t23), even if the driver steps on the accelerator again as in the previous time (FIG. 13A), the differential gain is lowered, so the vehicle acceleration does not increase. (FIG. 13B), it is possible to avoid a rapid decrease in the inter-vehicle distance (FIG. 13D).

  As described above in detail, according to the present embodiment, while looking at the inter-vehicle distance and the relative vehicle speed, the gain of differential control is lowered as the inter-vehicle distance becomes shorter and the relative speed becomes larger. When the degree of approach is high with respect to the vehicle ahead, the vehicle's responsiveness to the accelerator operation is reduced, so even if the driver steps on the accelerator too much due to a driver's operation error, etc. Can be prevented. Furthermore, because only the differential gain is lowered, if the driver keeps stepping on, it accelerates as before, so that unnecessary acceleration can be suppressed without giving the driver a sense of incongruity, improving fuel efficiency and improving safety. Can do it.

  The present invention is not limited to the embodiment described above, and various modifications and changes can be made within the scope of the technical idea, and it is obvious that these are equivalent to the present invention.

1 is a diagram showing a system configuration showing a first embodiment of a vehicle speed control device according to the present invention. FIG. 4 is a flowchart showing an operation of a control start determination unit 20. 4 is a block diagram showing a target vehicle speed calculation unit 30. FIG. 3 is an example of a target acceleration calculation map used in a target acceleration determination unit 31. 3 is a flowchart showing the operation of an integration processing unit 32. 6 is a diagram showing an example of a control gain correction value calculation map used in a control gain correction value calculation unit 70. FIG. 4 is a block diagram showing a vehicle speed control unit 40. FIG. 2 is a block diagram of a vehicle model 45. FIG. 3 is a block diagram showing a driving force distribution unit 60. FIG. 3 is an example of a gear ratio calculation map used in a gear ratio command value setting unit 61. It is a figure which shows the responsiveness improvement effect by differential control. It is a figure which shows an example of the problem of a prior art example. It is a figure which shows the effect by this invention.

Explanation of symbols

1 Control start switch 2 Brake switch (operation state detection means)
3 Accelerator opening sensor (operation state detection means)
4 Vehicle speed sensor 5 Engine rotation speed sensor 6 Engine ECU
7 Transmission ECU
9 Inter-vehicle distance sensor (traveling state detection means)
10 Vehicle speed control ECU
30 target vehicle speed calculation unit 40 vehicle speed control unit (vehicle speed control means)
50 Actual gear ratio calculation unit (vehicle speed control means)
60 Driving force distribution unit (vehicle speed control means)
70 Control gain correction value calculation unit (control gain correction means)

Claims (7)

Operation state detection means for detecting the operation state of the vehicle;
Target vehicle speed setting means for setting a target vehicle speed of the host vehicle based on the operation state;
An actual vehicle speed detecting means for detecting the actual vehicle speed of the own vehicle;
Vehicle speed control means for controlling the actual vehicle speed so as to match the target vehicle speed by feeding back the actual vehicle speed;
A traveling state detection means for detecting a relative traveling state between the preceding vehicle traveling in front of the own vehicle and the own vehicle;
Control gain correction means for correcting the control gain of the vehicle speed control means based on the relative running state of the host vehicle with respect to the preceding vehicle;
A vehicle speed control device. The control gain has a differential gain that is set based on the amount of change in the target vehicle speed per unit time, and a proportional gain that is set based on the difference between the target vehicle speed and the actual vehicle speed,
The control gain correction means corrects the differential gain;
The vehicle speed control device according to claim 1. The control gain has a differential gain that is set based on the amount of change in the target vehicle speed per unit time, and a proportional gain that is set based on the difference between the target vehicle speed and the actual vehicle speed,
The control gain correction means corrects the differential gain and the proportional gain;
The vehicle speed control device according to claim 1. The traveling state detection means detects a distance between the host vehicle and a preceding vehicle,
The control gain correction means corrects the control gain based on the inter-vehicle distance detected by the running state detection means;
The vehicle speed control device according to any one of claims 1 to 3, characterized in that: The control gain correction means corrects the control gain to be smaller as the inter-vehicle distance is closer.
The vehicle speed control device according to claim 4. The traveling state detection means detects the relative vehicle speed of the vehicle relative to the preceding vehicle,
The control gain correction means corrects the control gain based on the relative vehicle speed detected by the running state detection means;
The vehicle speed control device according to any one of claims 1 to 5, wherein the vehicle speed control device is provided. The control gain correction means corrects the control gain to be smaller as the speed at which the vehicle approaches the preceding vehicle is higher.
The vehicle speed control device according to claim 6.

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