JP2008155815A - Traveling controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a traveling controller for not deteriorating control performance while smoothly shifting a control value by each control in switching between constant speed traveling control and following traveling control. <P>SOLUTION: A traveling controller 100 having constant speed traveling control for controlling a vehicle speed V at a target vehicle speed V<SP>*</SP>by feedback control including integral control and having following traveling control for controlling an inter-vehicle distance X to a target inter-vehicle distance X<SP>*</SP>by the feedback control including the integral control includes: a control switching means SW1 for switching two control values of a control value Vx related to the following traveling control and a control value V<SP>*</SP>related to the constant traveling control, corresponding to each other, and for outputting either of the control values Vx, V<SP>*</SP>; a braking power control means 14 for controlling breaking power in the vehicle on the basis of a control value Vt output from the switching means SW1; and a traveling control means 1 for continuing traveling control by making the two control values Vx, V<SP>*</SP>, corresponding to each other, equivalent in switching by the switching means SW1. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a travel control device that executes a constant speed travel control that controls a vehicle speed to a target vehicle speed and a follow-up travel control that controls an inter-vehicle distance to a target inter-vehicle distance, and in particular, a control value related to a target vehicle speed and a target inter-vehicle distance. The present invention relates to a travel control device that smoothly changes a control value by each control when switching a control value related to a distance.

  Conventionally, a vehicle speed control unit that controls the vehicle speed so that the vehicle travels at a constant target speed at a predetermined target vehicle speed, and an inter-vehicle distance control unit that controls the inter-vehicle distance between the host vehicle and the preceding vehicle to be a predetermined target inter-vehicle distance, A travel control device is known that smoothly switches between control by a distance control unit and control by a vehicle speed control unit so as not to cause a step in a control amount that is finally output (see, for example, Patent Document 1). ).

  This travel control device adds the individual control ratios to the control amount by the inter-vehicle distance control unit and the control amount by the vehicle speed control unit, and adds them together to obtain the required control amount, and changes the individual control ratio according to the situation. However, the travel control actuator is controlled based on the required control amount.

  This travel control device sets the control ratio of the control amount by the vehicle speed control unit to be relatively higher as the inter-vehicle distance is larger, and as the relative speed between the host vehicle and the preceding vehicle is larger in the approaching direction, the inter-vehicle distance is increased. The control ratio of the control amount by the control unit is set to be relatively high.

  In addition, the smaller of the set vehicle speed set by the vehicle speed control unit and the set vehicle speed set by the inter-vehicle distance control unit is set as the target vehicle speed, and the acceleration is limited to a predetermined value or less when the current vehicle speed is shifted to the target vehicle speed. There is also known a vehicle speed control device that smoothly switches between control by a distance control unit and control by a vehicle speed control unit (see, for example, Patent Document 2).

Thus, the above-described travel control device or vehicle speed control device prevents a shock to the vehicle at the time of control switching.
Japanese Patent Laid-Open No. 7-17294 JP-A-11-227494

  However, the travel control device described in Patent Document 1 is a case where the switching from the vehicle speed control unit to the inter-vehicle distance control unit is performed suddenly, such as when another vehicle interrupts in front of the host vehicle due to a lane change. Gives priority to shock reduction and deteriorates the transitional distance control performance.

  Moreover, since the vehicle speed control apparatus described in Patent Document 2 allows only a slow change in the vehicle speed, the vehicle speed control device cannot cope with a case where the vehicle speed needs to be changed quickly and deteriorates the control performance.

  In view of the above-described points, an object of the present invention is to provide a travel control device that does not deteriorate the control performance while smoothly changing the control value of each control when switching between constant speed travel control and follow-up travel control. .

  In order to achieve the above object, a travel control device according to a first aspect of the present invention provides a constant speed travel control that controls a vehicle speed to a target vehicle speed by feedback control including integral control, and an inter-vehicle distance by feedback control including integral control. Is a travel control device having a follow-up travel control that controls the target inter-vehicle distance, and switches between two corresponding control values of the control value related to the follow-up travel control and the control value related to the constant speed travel control. Control switching means for outputting a value, braking / driving force control means for controlling braking / driving force in a vehicle based on a control value output by the control switching means, and the two corresponding control values at the time of switching by the control switching means And travel control means for continuing travel control with equality.

  Further, the second invention is a travel control device according to the first invention, wherein the travel control means sets the integral control initial value of the constant speed travel control or the follow-up travel control at the time of switching by the control switching means. The travel control is continued using the calculated integral control initial value.

  A third invention is a travel control device according to the first or second invention, wherein the control switching means sets a vehicle speed value for achieving a target inter-vehicle distance as a control value related to the follow-up travel control. A target vehicle speed value acquired as a first input and registered in advance as a control value related to the constant speed traveling control is acquired as a second input.

  A fourth aspect of the invention is a travel control apparatus according to the first or second aspect of the invention, wherein the control switching means is an engine braking / driving force for achieving a target inter-vehicle distance as a control value related to the follow-up travel control. A control value is acquired as a first input, and an engine braking / driving force control value for achieving a target vehicle speed is acquired as a second input as a control value related to the constant speed traveling control.

  With the above-described means, the present invention can provide a travel control device that does not deteriorate the control performance while smoothly shifting the control value of each control when switching between constant speed travel control and follow-up travel control.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings.

(1) Outline of Embodiment The travel control device according to the present invention is used for ACC (Auto Cruise Control) that controls travel of the host vehicle while switching between constant speed travel control and follow-up travel control.

  “Constant speed travel control” refers to the content of travel control that automatically controls the accelerator opening, brake amount, shift position, etc., so that the travel speed of the vehicle reaches a preset target vehicle speed. The `` travel control '' refers to the content of travel control that automatically controls the accelerator opening, brake amount, shift position, etc. so that the inter-vehicle distance between the host vehicle and the preceding vehicle becomes a preset target inter-vehicle distance. Say.

  In addition, when the traveling control device detects a preceding vehicle while executing the constant speed traveling control, the traveling control content is switched from the constant speed traveling control to the following traveling control, and the traveling control is continued. If the preceding vehicle is no longer present during the running control, the running control content is switched from the follow running control to the constant speed running control and the running control is continued.

  In addition, the travel control apparatus acquires physical quantities controlled by various sensors based on the output value (control value) of the control circuit using PID (Proportional-Integral-Derivative) control, and controls the acquired physical quantity values. The input value is changed by feeding back to the circuit so that the physical quantity value approaches the target value.

  “Control value” refers to control of motors, actuators, etc. that control the control target physical quantities such as engine driving force, accelerator opening, brake amount, vehicle speed, shift position, etc. This is the value to be input to the device.

  “PID control” is one type of feedback control, and is a method of performing control of an input value by three elements of a deviation between an output value and a target value, an integral thereof, and a derivative thereof, Proportional control to change the input value in proportion to the deviation, integral control to change the input value in proportion to the time that the deviation continues, proportional to the magnitude of the change when a sudden change in the control value occurs Thus, the control method combines differential control for changing the input value.

  The “control circuit” includes, for example, a vehicle speed controller having a vehicle speed deviation that is a difference between the target vehicle speed and the actual vehicle speed as an input value and an engine braking / driving force control value as an output value, and a target inter-vehicle distance and There is an inter-vehicle distance controller that uses an inter-vehicle distance deviation, which is a difference between the actual inter-vehicle distances, as an input value and an output value that is a target vehicle speed for calculating a value that becomes an input value of the vehicle speed controller.

  The “engine braking / driving force control value” is desired by driving a braking / driving force control device such as an accelerator control device, a brake control device, or a shift position control device that controls the braking / driving force of the engine in a predetermined state. This is a value for obtaining the engine driving force.

  In addition, the travel control device switches the target vehicle speed set for constant speed travel control to the target vehicle speed output by the inter-vehicle distance controller by the control changeover switch, and the target vehicle speed output by the inter-vehicle distance controller and the actual vehicle speed. The vehicle speed deviation calculated based on the above is input to the vehicle speed controller to obtain the engine braking / driving force control value.

  The control changeover switch switches the target vehicle speed set for constant speed travel control to the target vehicle speed output by the intervehicular distance controller when the intervehicular distance becomes less than a predetermined value. The switching of the traveling control content to is realized.

  The inter-vehicle distance controller controls the initial value of the integral control (constant speed running) so that the target vehicle speed, which is the output value, is equal to the target vehicle speed set for constant speed running control during constant speed running control. The deviation integration amount at the time when the travel control content is switched from the control to the follow-up travel control is zero because the deviation has not yet continued, and the value of the integral control term in the PID control is the initial value itself. )) Periodically in the background, and when the target vehicle speed is switched by the control changeover switch, the same target vehicle speed as the target vehicle speed set for constant speed traveling control can be provided as the output value. To. Note that the value of the integral control term in the PID control changes with time while adding the deviation integral amount to the initial value.

  In addition, the inter-vehicle distance controller performs calculation for the first time when the target vehicle speed is switched by the control changeover switch, and provides the same target vehicle speed as the output value that is the same as the target vehicle speed set for constant speed traveling control. It may be.

  After that, the inter-vehicle distance controller changes the inter-vehicle distance deviation as an input value so that the actual inter-vehicle distance becomes the target inter-vehicle distance by PID control (strictly speaking, the actual inter-vehicle distance is changed by changing the engine braking / driving force). The target vehicle speed is output, and the vehicle speed controller changes the target vehicle speed output by the inter-vehicle distance controller and the actual vehicle speed as an input value. (Strictly speaking, by changing the engine braking / driving force to change the actual vehicle speed, the vehicle speed deviation is converged to zero.) The engine braking / driving force control value is output.

As described above, the travel control device determines the target vehicle speed for calculating the vehicle speed deviation that is the input value of the vehicle speed controller even when the travel control content is switched from the constant speed travel control to the follow-up travel control. Since it is continuously changed without changing in steps, the engine braking / driving force control value, which is the output value of the vehicle speed controller, is suddenly changed to make the vehicle behavior unstable (for example, the engine braking / driving force changes suddenly). To generate a shock such as sudden acceleration or sudden deceleration.).
(2) Details of Embodiment FIG. 1 is a block diagram showing a configuration example of a travel control device according to the present invention. A travel control device 100 includes a control unit 1, an inter-vehicle distance sensor 2, a vehicle speed sensor 3, and a storage device 4. , An accelerator control device 5, a brake control device 6, and a shift position control device 7.

  The control unit 1 obtains data from the inter-vehicle distance sensor 2, the vehicle speed sensor 3, and the storage device 4, and calculates an control circuit to output to the accelerator control device 5, the brake control device 6, and the shift position control device 7. It is.

  The inter-vehicle distance sensor 2 is for measuring a distance between a vehicle (hereinafter referred to as “own vehicle”) on which the travel control device 100 is mounted and another vehicle (hereinafter referred to as “other vehicle”). The sensor is, for example, a laser radar, a millimeter wave radar, an image sensor (stereo camera), an ultrasonic sensor, or the like attached to the lower part of the front bumper of the own vehicle, and outputs measured data to the control unit 1. The inter-vehicle distance sensor 2 may calculate a relative speed between the host vehicle and the other vehicle from the temporal change in the measured inter-vehicle distance and output the relative speed to the control unit 1.

  The vehicle speed sensor 3 is a sensor that measures the traveling speed of the host vehicle. For example, an MR (Magnetic Resistance) element reads a change in a magnetic field caused by a magnet attached to each wheel and rotating together with each wheel, and rotates the magnetic resistance. The rotational speed of the wheel and the traveling speed of the vehicle are measured by taking out as a pulse signal proportional to the speed, and the measured data is output to the control unit 1.

  The storage device 4 is a device for storing various data necessary for the travel control device 100 to execute constant speed travel control or follow-up travel control. For example, the storage device 4 is a storage medium such as a hard disk or a flash memory. A target vehicle speed for high-speed driving control and a target inter-vehicle distance for following driving control are stored. The storage device 4 outputs various data to the control unit 1 in response to an inquiry from the control unit 1. Note that the value of the target vehicle speed for the constant speed traveling control or the target inter-vehicle distance for the following traveling control is stored so as to be changeable via an input means such as a touch panel or an escutcheon switch.

  The accelerator control device 5, the brake control device 6, and the shift position control device 7 are braking / driving force control devices for automatically controlling the traveling speed of the host vehicle. For example, the motor is based on a control signal output from the control unit 1. Or the actuator is driven to adjust the accelerator opening, the braking force, or the shift position to change the traveling speed of the vehicle.

  FIG. 2 is a block diagram illustrating a configuration example of the control unit 1. The control unit 1 includes a target inter-vehicle distance acquisition unit 10, an actual inter-vehicle distance acquisition unit 11, a target vehicle speed acquisition unit 12, an actual vehicle speed acquisition unit 13, and braking / driving. It comprises a force control unit 14, computing units P1, P2, an inter-vehicle distance controller C1, a vehicle speed controller C2, and a control changeover switch SW1.

  The target inter-vehicle distance acquisition unit 10 is a means for acquiring a target inter-vehicle distance for follow-up running control, and for example, acquires a target inter-vehicle distance X * by reading a value stored in the storage device 4.

  The actual inter-vehicle distance acquisition unit 11 is a means for acquiring an actual inter-vehicle distance between the own vehicle and another vehicle traveling in front of the own vehicle (hereinafter referred to as “actual inter-vehicle distance”). The actual inter-vehicle distance X is acquired based on the data measured by the inter-vehicle distance sensor 2 mounted on the host vehicle.

  The target vehicle speed acquisition unit 12 is a means for acquiring a target vehicle speed for constant speed traveling control. For example, the target vehicle speed V * is acquired by reading a value stored in the storage device 4.

  The actual vehicle speed acquisition unit 13 is a means for acquiring the actual traveling speed of the own vehicle (hereinafter referred to as “actual vehicle speed”), and is based on, for example, data measured by the vehicle speed sensor 3 mounted on the own vehicle. To obtain the actual vehicle speed V.

  The braking / driving force control unit 14 is a means for outputting a control signal to the braking / driving force control device mounted on the host vehicle. For example, based on the final control value Ft acquired as an input, the accelerator control device 5, the brake A control signal corresponding to each braking / driving force control device is output to each of the control device 6 and the shift position control device 7.

  The calculator P1 is a circuit that obtains the target inter-vehicle distance X * and the actual inter-vehicle distance X as inputs and outputs an inter-vehicle distance deviation Xe that is a difference between the target inter-vehicle distance X * and the actual inter-vehicle distance X. The device P2 is a circuit that obtains the final target vehicle speed Vt and the actual vehicle speed V as inputs and outputs a vehicle speed deviation Ve that is a difference between the final target vehicle speed Vt and the actual vehicle speed V.

  The inter-vehicle distance controller C1 is a PID controller that acquires the inter-vehicle distance deviation Xe as an input and outputs a target vehicle speed Vx for follow-up running control. The vehicle speed controller C2 acquires the vehicle speed deviation Ve as an input and obtains the desired vehicle speed Vx. This is a PID controller that outputs a final control value Ft for obtaining the vehicle speed.

  3A and 3B are diagrams showing a configuration example of the PID controller. FIG. 3A shows the inter-vehicle distance controller C1, and FIG. 3B shows the vehicle speed controller C2.

  The inter-vehicle distance controller C1 acquires the inter-vehicle distance deviation Xe as an input, and obtains the proportional gain Kp1 (first term), the product of the differential gain Kd1 and the differential dXe / dt value of the inter-vehicle distance deviation Xe (second term), The value obtained by adding three terms (the third term) of the product of the integral gain Ki1 and the integral value Xedt of the inter-vehicle distance deviation Xe plus the initial value α (third term) is the target vehicle speed Vx for the follow-up running control. Output as. In addition, Formula (1) showing the above-mentioned relationship is as follows.

なお、第二項における車間距離偏差Ｘｅの微分ｄＸｅ／ｄｔの値は、車間距離センサ２が測定した自車と他車との間の相対速度Ｖｒをそのまま用いるようにしてもよい。

Note that as the value of the differential dXe / dt of the inter-vehicle distance deviation Xe in the second term, the relative speed Vr between the own vehicle and the other vehicle measured by the inter-vehicle distance sensor 2 may be used as it is.

  Further, the vehicle speed controller C2 acquires the vehicle speed deviation Ve as an input, and obtains a proportional gain Kp2 (first term), a product of the differential gain Kd2 and the differential dVe / dt value of the vehicle speed deviation Ve (second term), and The final control for the braking / driving force control unit 14 to output to the braking / driving force control device a value obtained by adding the three terms of the product (third term) of the integral gain Ki2 and the integral ∫Vedt value of the vehicle speed deviation Ve. Output as value Ft. The mathematical formula (2) representing the above relationship is as follows.

なお、比例ゲインＫｐ１、Ｋｐ２、微分ゲインＫｄ１、Ｋｄ２、積分ゲインＫｉ１、Ｋｉ２は、最適レギュレータ法や極配置法によって、制御切り替え時の状況に応じた最適な値が設定されており、制御切り替え時の制御性能を損なうことは無いものとする。

The proportional gains Kp1, Kp2, differential gains Kd1, Kd2, integral gains Ki1, Ki2 are set to optimum values according to the situation at the time of control switching by the optimal regulator method or pole placement method. It is assumed that the control performance is not impaired.

  The control changeover switch SW1 acquires, as inputs, the target vehicle speed V * for constant speed travel control acquired by the target vehicle speed acquisition unit 12 and the target vehicle speed Vx for follow-up travel control output by the inter-vehicle distance controller C1, This is a switch for outputting either one as the final target vehicle speed Vt. When the actual inter-vehicle distance X measured by the inter-vehicle distance sensor 2 is less than a predetermined value, the final target vehicle speed Vt that is output is controlled at a constant speed. The target vehicle speed V * for the vehicle is switched to the target vehicle speed Vx for the following traveling control.

  The control unit 1 calculates the inter-vehicle distance deviation Xe by the calculator P1 based on the target inter-vehicle distance X * acquired by the target inter-vehicle distance acquisition unit 10 and the actual inter-vehicle distance X acquired by the actual inter-vehicle distance acquisition unit 11. The inter-vehicle distance controller C1 causes the inter-vehicle distance controller C1 to input the target vehicle speed Vx for follow-up traveling control to the input terminal E2 of the control changeover switch SW1 by PID control.

  In addition, the control unit 1 causes the target vehicle speed V * for constant speed traveling control acquired by the target vehicle speed acquisition unit 12 to be input to the input terminal E1 of the control switch SW1, and the control switch SW1 is connected to the inter-vehicle distance sensor 2. When the measured actual inter-vehicle distance X is equal to or greater than a predetermined value, the target vehicle speed V * for constant speed traveling control is output as the final target vehicle speed Vt, and the actual inter-vehicle distance X measured by the inter-vehicle distance sensor 2 is less than the predetermined value. In this case, the target vehicle speed Vx for the follow-up traveling control is output as the final target vehicle speed Vt.

  Further, the control unit 1 calculates the vehicle speed deviation Ve by the computing unit P2 based on the final target vehicle speed Vt output by the control changeover switch SW1 and the actual vehicle speed V acquired by the actual vehicle speed acquisition unit 13, and sends the vehicle speed deviation Ve to the vehicle speed controller C2. The vehicle speed controller C2 inputs the final control value Ft to the braking / driving force control unit 14 by PID control.

  The control unit 1 may be a computer having a central processing unit (CPU), a random access memory (RAM), a read only memory (ROM), a non-volatile random access memory (NVRAM), and the like. Distance acquisition unit 10, actual inter-vehicle distance acquisition unit 11, target vehicle speed acquisition unit 12, actual vehicle speed acquisition unit 13, braking / driving force control unit 14, calculators P1, P2, inter-vehicle distance controller C1, vehicle speed controller C2, and control switching A program corresponding to each of the switches SW1 may be stored in the NVRAM, and the programs may be expanded on the RAM to cause the CPU to execute corresponding processing.

  Next, a flow of processing in which the traveling control device 100 switches the traveling control content will be described. FIG. 4 is a flowchart showing the flow of the switching process.

  First, the control unit 1 acquires the actual inter-vehicle distance X via the inter-vehicle distance sensor 2 by the actual inter-vehicle distance acquisition unit 11 and acquires the actual vehicle speed V via the vehicle speed sensor 3 by the actual vehicle speed acquisition unit 13. (Step S1).

  Thereafter, the control unit 1 determines whether or not to switch the travel control content based on the actual inter-vehicle distance X acquired by the actual inter-vehicle distance acquisition unit 11 (step S2).

  When the actual inter-vehicle distance X is equal to or greater than a predetermined value, the control unit 1 switches the travel control content from the follow-up travel control to the constant speed travel control (following travel → constant speed travel in Step S2), and for the constant speed travel control. The target vehicle speed Vx for follow-up running control at the time of switching is set to the target vehicle speed V * (step S3).

  Thereafter, the control unit 1 switches the connection at the control changeover switch SW1 from the input terminal E2 to the input terminal E1 (step S4), and the target vehicle speed V * for constant speed traveling control (currently set to Vx). Is the final target vehicle speed Vt, the vehicle speed deviation Ve is calculated by the calculator P2, and the final control value Ft is obtained. Here, the control unit 1 changes the setting so that the target vehicle speed for the constant speed traveling control gradually approaches the initial V * from Vx at a predetermined interval, while the actual vehicle speed V is the target for the constant speed traveling control. Control is performed to reach the vehicle speed V *.

  The control unit 1 sets the travel control content from the following travel control to the constant speed travel control without setting the target vehicle speed Vx for the following travel control at the time of switching to the target vehicle speed V * for the constant speed travel control. You may make it switch.

  In this case, the control unit 1 changes the final control value Ft within a predetermined control range (refers to limiting the rate of change of the final control value Ft) and sets the actual vehicle speed V to a target for constant speed traveling control. Let the vehicle speed V * be reached.

  On the other hand, when the actual inter-vehicle distance X becomes less than the predetermined value, the control unit 1 switches the travel control content from the constant speed travel control to the follow travel control (constant speed travel → follow travel in step S2), and the follow travel control. The target vehicle speed V * for constant speed travel control is set as the target vehicle speed Vx for calculating the initial value α in the third term of the inter-vehicle distance controller C1 (step S5). Note that the target vehicle speed V * for constant speed traveling control is a value that was used as the final target vehicle speed Vt until the control is switched by the control switch SW1.

  The initial value α is derived by the following formula (3) by substituting V * into Vx of the formula (1). Note that the value of the integral ∫ Xedt of the inter-vehicle distance deviation Xe at the time of switching is zero.

仮に初期値αが算出されなかった場合（初期値αがゼロであるか、或いは、無意味な値が設定されている場合をいう。）、制御切り替えスイッチＳＷ１によって制御が切り替えられた時点における追従走行制御のための目標車速Ｖｘは、異常な値となってしまう場合があり、異常な目標車速Ｖｘに基づいて導出される最終制御値Ｆｔも異常な値となり自車の挙動を不安定にしてしまう。

If the initial value α is not calculated (the initial value α is zero or a meaningless value is set), the tracking at the time when the control is switched by the control switch SW1. The target vehicle speed Vx for travel control may become an abnormal value, and the final control value Ft derived based on the abnormal target vehicle speed Vx also becomes an abnormal value, which makes the behavior of the host vehicle unstable. End up.

  Therefore, by deriving the initial value α as described above, the control unit 1 makes the behavior of the host vehicle unstable even when the travel control content is switched from constant speed travel control to follow-up travel control. Can be prevented.

  Thereafter, the control unit 1 switches the connection at the control changeover switch SW1 from the input terminal E1 to the input terminal E2 (step S6), and finally sets the target vehicle speed Vx (currently V *) for follow-up running control. The vehicle speed deviation Ve is calculated by the calculator P2 as the target vehicle speed Vt, and the final control value Ft is obtained by the vehicle speed controller C2.

  Thereafter, the control unit 1 changes the target vehicle speed Vx for follow-up running control so that the inter-vehicle distance deviation Xe converges to zero by PID control in the inter-vehicle distance controller C1, and the vehicle speed by PID control in the vehicle speed controller C2. The vehicle is caused to travel while changing the final control value Ft so that the deviation Ve converges to zero.

  With the above configuration, the travel control device 100 prevents the control value from changing discontinuously at the time of switching the travel control content by calculating the initial value of the integral control, so that the control value changes discontinuously. In order to stabilize the behavior of the vehicle, the time constant of the feedback control (the constant for determining the response speed after the start of control) is changed according to the situation at the time of switching the traveling control content, and others This makes it possible to stabilize the behavior of the vehicle at the time of switching the travel control contents without having to change the adjustment parameters.

  In addition, the traveling control device 100 prevents the control value at the time of switching the traveling control from changing discontinuously without changing the time constant of the feedback control or changing other adjustment parameters. The response speed can be improved without degrading the control performance while stabilizing the behavior of the vehicle at the time of switching the control contents.

  Further, the travel control device 100 uses the vehicle speed controller C2 as an inner loop (directly connected to the braking / driving force control unit 14) and the inter-vehicle distance controller C1 as an outer loop (provided to the braking / driving force control unit 14). Indirect connection)), the responsiveness of the speed control can be further improved while stabilizing the behavior of the vehicle at the time of switching the traveling control content.

  Next, another embodiment of the travel control device according to the present invention will be described. FIG. 5 is a block diagram illustrating another configuration example of the control unit.

  As shown in FIG. 5, the control unit 1A of the travel control device 100A connects the inter-vehicle distance controller C3 and the vehicle speed controller C4 in parallel to the control changeover switch SW2 (hereinafter, this configuration is referred to as “independent feedback configuration”). In this regard, the three units are connected in series in the order of the inter-vehicle distance controller C1, the control switch SW1 and the vehicle speed controller C2 (hereinafter, this configuration is referred to as “double feedback configuration”). This is different from FIG.

  The control unit 1A calculates the inter-vehicle distance deviation Xe by the calculator P1 based on the target inter-vehicle distance X * acquired by the target inter-vehicle distance acquisition unit 10 and the actual inter-vehicle distance X acquired by the actual inter-vehicle distance acquisition unit 11. The inter-vehicle distance controller C3 causes the inter-vehicle distance controller C3 to input a control value Fx for follow-up traveling control to the input terminal E4 of the control changeover switch SW2 by PID control.

  Further, the control unit 1A uses the calculator P2 to calculate the vehicle speed deviation Ve based on the target vehicle speed V * for constant speed travel control acquired by the target vehicle speed acquisition unit 12 and the actual vehicle speed V obtained by the actual vehicle speed acquisition unit 13. Is input to the vehicle speed controller C4, and the vehicle speed controller C4 inputs a control value Fv for constant speed traveling control to the input terminal E3 of the control changeover switch SW2 by PID control.

  When the actual inter-vehicle distance X measured by the inter-vehicle distance sensor 2 is greater than or equal to a predetermined value, the control changeover switch SW2 outputs a control value Fv for constant speed traveling control as the final control value Ft, and the inter-vehicle distance sensor 2 measures When the actual inter-vehicle distance X is less than the predetermined value, the control value Fx for follow-up running control is output as the final control value Ft, and the final control value Ft is input to the braking / driving force control unit 14.

  FIG. 6 is a diagram illustrating a configuration example of a PID controller. FIG. 6A illustrates an inter-vehicle distance controller C3, and FIG. 6B illustrates a vehicle speed controller C4.

  Similar to the inter-vehicle distance controller C1 in FIG. 3A, the inter-vehicle distance controller C3 acquires the inter-vehicle distance deviation Xe as an input and outputs a control value Fx for follow-up traveling control. Formula (4) representing control in the inter-vehicle distance controller C3 is as follows.

また、車速制御器Ｃ４は、図３（Ｂ）における車速制御器Ｃ２と同様、車速偏差Ｖｅを入力として取得し、定速走行制御のための制御値Ｆｖを出力する。なお、車速制御器Ｃ４における制御を表す数式（５）は、以下のようになる。

Similarly to the vehicle speed controller C2 in FIG. 3B, the vehicle speed controller C4 acquires the vehicle speed deviation Ve as an input, and outputs a control value Fv for constant speed traveling control. Formula (5) representing control in the vehicle speed controller C4 is as follows.

なお、比例ゲインＫｐ３、Ｋｐ４、微分ゲインＫｄ３、Ｋｄ４、積分ゲインＫｉ３、Ｋｉ４は、最適レギュレータ法や極配置法によって、制御切り替え時の状況に応じた最適な値が設定されており、制御切り替え時の制御性能を損なうことは無いものとする。

The proportional gains Kp3 and Kp4, the differential gains Kd3 and Kd4, and the integral gains Ki3 and Ki4 are set to optimum values according to the situation at the time of control switching by the optimal regulator method or pole placement method. It is assumed that the control performance is not impaired.

  The control changeover switch SW2 acquires, as inputs, a control value Fx for follow-up running control output from the inter-vehicle distance controller C3 and a control value Fv for constant speed running control output from the vehicle speed controller C4. This is a switch for outputting one as the final control value Ft, and when the actual inter-vehicle distance X measured by the inter-vehicle distance sensor 2 is less than a predetermined value, the final control value Ft to be output is used for constant speed traveling control. The control value Fv is switched to the control value Fx for follow-up running control.

  At that time, the control unit 1A sets a control value Fv for constant speed traveling control as a control value Fx for follow-up traveling control, and calculates an initial value β in the third term of the inter-vehicle distance controller C3. Note that the control value Fv for the constant speed traveling control is a value that was actually used as the final control value Ft until the control is switched by the control selector switch SW2.

  The initial value β is derived by the following formula (6) by substituting Fv into Fx of the formula (4). Note that the value of the integral ∫ Xedt of the inter-vehicle distance deviation Xe at the time of switching is zero.

このようにして、制御部１Ａは、定速走行制御から追従走行制御に走行制御内容が切り替えられた場合にも最終制御値Ｆｔを連続的に変化させることで、自車の挙動が不安定となるのを防止することができる。

In this way, the control unit 1A continuously changes the final control value Ft even when the travel control content is switched from the constant speed travel control to the follow-up travel control. Can be prevented.

  On the other hand, when the actual inter-vehicle distance X measured by the inter-vehicle distance sensor 2 becomes equal to or greater than a predetermined value, the control changeover switch SW2 changes the final control value Ft to be output from the control value Fx for follow-up traveling control to constant speed traveling control. Is switched to the control value Fv.

  At that time, the control unit 1A sets the control value Fx for the follow-up traveling control to the control value Fv for the constant speed traveling control, and calculates the initial value γ in the third term of the vehicle speed controller C4. Note that the control value Fx for the follow-up running control is a value that was actually used as the final control value Ft until switching by the control changeover switch SW2.

  The initial value γ is derived by the following formula (7) by substituting Fx into Fv of the formula (5). Note that the value of the integral ∫Vedt of the vehicle speed deviation Ve at the time of switching is zero.

このように、制御部１Ａは、定速走行制御から追従走行制御に走行制御内容が切り替えられた場合と同様、追従走行制御から定速走行制御に走行制御内容が切り替えられた場合にも最終制御値Ｆｔを連続的に変化させることで、自車の挙動が不安定となるのを防止することができる。

As described above, the control unit 1A performs the final control even when the travel control content is switched from the follow-up travel control to the constant-speed travel control, in the same manner as when the travel control content is switched from the constant-speed travel control to the follow-up travel control. By continuously changing the value Ft, it is possible to prevent the behavior of the vehicle from becoming unstable.

  With the above configuration, the travel control device 100A calculates the initial value of the integral control so that the control value does not change discontinuously at the time when the travel control content is switched. While stabilizing the behavior, the response speed can be improved without impairing the control performance.

  In addition, since the traveling control device 100A employs an independent feedback configuration, it is possible to continue predetermined traveling control even when either the inter-vehicle distance controller C3 or the vehicle speed controller C4 fails.

  Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the present invention. Can be added.

  For example, in the above-described embodiment, the control unit 1A employs an independent feedback configuration in which the inter-vehicle distance controller C3 and the vehicle speed controller C4 are connected in parallel to the control changeover switch SW2, and the control unit 1 performs inter-vehicle distance control. The dual feedback configuration in which the three components are connected in series in the order of the device C1, the control changeover switch SW1, and the vehicle speed controller C2 is adopted, but the independent feedback configuration and the dual feedback configuration may be combined.

  Moreover, although the above-mentioned Example stabilizes the behavior of the own vehicle at the time of switching between constant speed traveling control and follow-up traveling control, a lane in which the other vehicle traveling in front of the own vehicle travels by changing the lane. If the other vehicle that was traveling ahead of the other vehicle becomes a preceding vehicle, the behavior of the vehicle at the time when the actual inter-vehicle distance X changes discontinuously should be stabilized. Also good.

It is a block diagram which shows the structural example of the traveling control apparatus which concerns on this invention. It is a block diagram (the 1) which shows the example of a structure of a control part. It is a figure (the 1) which shows the structural example of a PID controller. It is a flowchart which shows the flow of the process which a traveling control apparatus switches the content of traveling control. It is a block diagram (the 2) which shows the structural example of a control part. It is a figure (the 2) which shows the structural example of a PID controller.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1A control part 2 Inter-vehicle distance sensor 3 Vehicle speed sensor 4 Memory | storage device 5 Accelerator control apparatus 6 Brake control apparatus 7 Shift position control apparatus 10 Target inter-vehicle distance acquisition part 11 Actual inter-vehicle distance acquisition part 12 Target vehicle speed acquisition part 13 Actual vehicle speed acquisition part 14 Braking / driving force control unit 100, 100A Travel control device C1, C3 Inter-vehicle distance controller C2, C4 Vehicle speed controller E1-E4 Input terminal Ft Final control value Fv Control value for constant speed travel control Fx For tracking travel control Control value of Kd1 to Kd4 Differential gain Ki1 to Ki4 Integral gain Kp1 to Kp4 Proportional gain P1, P2 Controller X Distance between actual vehicles Xe Distance between vehicles X * Target distance between vehicles V Actual vehicle speed Ve Vehicle speed deviation Vx Target for follow-up control Vehicle speed Vt Final target vehicle speed V * Target vehicle speed for constant-speed driving control α, β Initial inter-vehicle distance deviation integration Value γ Initial value of vehicle speed deviation integral

Claims (4)

A travel control device having a constant speed travel control for controlling the vehicle speed to a target vehicle speed by feedback control including integral control, and a follow-up travel control for controlling the inter-vehicle distance to the target inter-vehicle distance by feedback control including integral control,
Control switching means for switching between two corresponding control values of the control value relating to the follow-up running control and the control value relating to the constant speed running control and outputting any one of the control values;
Braking / driving force control means for controlling braking / driving force in the vehicle based on a control value output by the control switching means;
Travel control means for equalizing the two corresponding control values at the time of switching by the control switching means and continuing travel control;
A travel control device comprising: The travel control means calculates an integral control initial value of the constant speed travel control or the follow-up travel control at the time of switching by the control switching means, and continues the travel control using the integral control initial value;
The travel control apparatus according to claim 1. The control switching means obtains, as a first input, a vehicle speed value for achieving the target inter-vehicle distance as a control value related to the following travel control, and a target registered in advance as a control value related to the constant speed travel control Get the vehicle speed value as the second input,
The travel control device according to claim 1 or 2, wherein The control switching means acquires, as a first input, an engine braking / driving force control value for achieving a target inter-vehicle distance as a control value related to the following traveling control, and a target vehicle speed as a control value related to the constant speed traveling control. Obtaining the engine braking / driving force control value as a second input to achieve
The travel control device according to claim 1 or 2, wherein

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