JP2020077140A - Travel control device and travel control method - Google Patents

Abstract

To provide a travel control device and a travel control method capable of controlling an own vehicle to a target inter-vehicle distance by reducing sudden acceleration in controlling follow-up travel using sliding mode control.SOLUTION: A travel control device CTS of the present invention includes a travel state measurement part 1 for measuring a travel state of an own vehicle, a first travel control part 22 for controlling travel of the own vehicle so as to follow the preceding vehicle with sliding mode control using a target sliding mode surface (SM surface) including a target travel state, and a second travel control part 23 for controlling the travel of the own vehicle until converging the travel state of the own vehicle to the target SM surface. The second travel control part 23 performs setting processing for setting a temporary SM surface on the basis of the measured travel state of the own vehicle, performs auxiliary travel control for controlling the travel of the own vehicle with sliding mode control using the temporary SM surface, and repeats the setting processing and the auxiliary travel control until converging the temporary SM surface to the target SM surface.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a travel control device and a travel control method for controlling the travel of the host vehicle so as to follow a preceding vehicle preceding the host vehicle.

  BACKGROUND ART Conventionally, there is known a traveling control device that controls traveling of the host vehicle so as to follow the preceding vehicle while maintaining an inter-vehicle distance from the preceding vehicle preceding the host vehicle at an appropriate predetermined distance (for example, Patent Document 1). 1st grade). When such follow-up running control is realized by so-called PID control, when the inter-vehicle distance during the follow-up running control approaches the target inter-vehicle distance, overshoot and undershoot are repeated with respect to the target inter-vehicle distance. While converging on the target inter-vehicle distance. The vehicle is accelerated and decelerated when these overshoots and undershoots are repeated. Therefore, such control is not preferable in consideration of ride comfort of the passenger. Therefore, sliding mode control is known as a control method for controlling a target without overshooting, and is also applied to a vehicle (for example, Patent Document 2). This sliding mode control is a non-linear control having good robustness, and generally, a sliding mode surface (hyperplane) for sliding mode control is defined by a linear function having a plurality of state quantities to be controlled as variables. The state quantity is set to converge on the sliding mode surface, and the state quantity is converged to an equilibrium point on the sliding mode surface while constraining the state quantity on the sliding mode surface. This is a method of controlling the quantity to a target state quantity.

JP, 2005-155249, A JP2012-003452A

  By the way, in such a sliding mode control, when the state quantity is converged to the equilibrium point on the sliding mode surface while restraining the state quantity on the sliding mode surface, for example, the relative speed of the host vehicle with respect to the preceding vehicle or Since the state quantity such as the inter-vehicle distance transits on the sliding mode surface, the host vehicle can be controlled to the target inter-vehicle distance without causing rapid acceleration / deceleration. However, when the state quantity of the host vehicle at the time of starting the sliding mode control deviates relatively from the sliding mode surface, the state quantity of the own vehicle is placed on the sliding mode surface. There is a risk that relatively rapid acceleration / deceleration will occur.

  The present invention is made in view of the above circumstances, and an object of the present invention is to reduce sudden acceleration / deceleration during control of follow-up travel using sliding mode control, to achieve a desired inter-vehicle distance. A travel control device and a travel control method capable of controlling a vehicle.

  As a result of various studies, the present inventor has found that the above object can be achieved by the present invention described below. That is, the traveling control device according to one aspect of the present invention is a traveling mode control unit that measures a traveling state of the host vehicle and a sliding mode control using a target sliding mode surface including the target traveling state, A first traveling control unit that controls the traveling of the host vehicle so as to follow the preceding vehicle preceding the vehicle, and controls the traveling of the host vehicle until the traveling state of the host vehicle converges on the target sliding mode surface. A second traveling control unit, and the second traveling control unit performs a setting process for setting a provisional sliding mode surface based on the traveling state of the vehicle measured by the traveling state measuring unit; An auxiliary traveling control unit that performs auxiliary traveling control that controls traveling of the own vehicle by sliding mode control using the temporary sliding mode surface set by the setting unit, A repeating unit that causes the setting unit and the auxiliary traveling control unit to repeatedly perform the setting process and the auxiliary traveling control, respectively, until the provisional sliding mode surface set by the setting unit converges on the target sliding mode surface. With. Preferably, in the above-described traveling control device, the traveling state is an inter-vehicle distance and a relative speed of the host vehicle with respect to the preceding vehicle. Preferably, in the above-described traveling control device, the target sliding mode surface is set in a coordinate space whose coordinate axes are the inter-vehicle distance and the relative speed of the own vehicle with respect to the preceding vehicle, and a predetermined target set in advance. It is expressed by a predetermined function that is set in advance and passes through the point where the relative speed is 0, which is the inter-vehicle distance.

  Such a traveling control device sets the provisional sliding mode surface based on the traveling state of the vehicle until the provisional sliding mode surface converges on the target sliding mode surface, and uses the provisional sliding mode surface. Since the running mode of the host vehicle is controlled by the sliding mode control, the driving speed of the host vehicle is controlled more rapidly than in the case where the host vehicle is controlled so that the running state of the host vehicle is included in the target sliding mode surface. Deceleration can be reduced. Therefore, the traveling control device can control the own vehicle up to the target inter-vehicle distance by reducing rapid acceleration / deceleration during the follow-up traveling control using the sliding mode control.

  In another aspect, in the above-described traveling control device, the setting unit is parallel to the target sliding mode surface, and a parallel surface including the traveling state of the own vehicle measured by the traveling state measuring unit, The provisional sliding mode surface is set in parallel with the target sliding mode surface in parallel with the target sliding mode surface.

  Since such a traveling control device sets the temporary sliding mode surface in parallel to the target sliding mode surface, the sliding mode control using the temporary sliding mode surface and the sliding mode using the target sliding mode surface are performed. Both controls can be controlled with substantially the same acceleration. Therefore, the traveling control device can control the own vehicle to the target inter-vehicle distance by decelerating at a substantially constant speed or increasing the speed at a substantially constant speed.

  In another aspect, in the above-described traveling control device, the setting unit determines, based on the traveling state of the own vehicle measured by the traveling state measuring unit, a time until the own vehicle collides with the preceding vehicle. Then, the provisional sliding mode surface is set based on the obtained collision margin time.

  Since such a traveling control device sets the temporary sliding mode surface based on the collision allowance time, the time until the temporary sliding mode surface converges to the target sliding mode surface in consideration of the collision allowance time. Can be adjusted.

  In another aspect, in the above-described traveling control device, the temporary sliding mode surface is set so that the shorter the calculated collision margin time is, the closer to the target sliding mode surface.

  Such a travel control device sets a temporary sliding mode surface such that the shorter the collision allowance time is, the closer it is to the target sliding mode surface. Therefore, when the collision allowance time is relatively short, there is a risk of collision. The temporary sliding mode surface can be converged to the target sliding mode surface in a relatively short time while avoiding, while the temporary sliding mode surface is gradually increased in a relatively long time when the collision margin time is relatively long. A surface can be converged to the target sliding mode surface.

  In another aspect, in the above-described traveling control device, the traveling state is an inter-vehicle distance and a relative speed of the own vehicle with respect to the preceding vehicle, and the target sliding mode surface is the inter-vehicle distance and the relative speed. It is expressed by a predetermined function that passes through a point having a predetermined target inter-vehicle distance and a relative speed of 0, which is set in a coordinate space having the speed as a coordinate axis, and the setting unit is parallel to the sliding mode plane of the target. And a second distance passing through a coordinate point of a relative speed closer to the target sliding mode surface by a predetermined value than the inter-vehicle distance measured by the running condition measuring unit and the relative speed measured by the running condition measuring unit. A parallel surface is set as the temporary sliding mode surface.

  According to this, it is possible to provide a traveling control device that can set a temporary sliding mode surface that is close to the target sliding mode surface by a predetermined value.

  A traveling control method according to another aspect of the present invention is a traveling state measuring step of measuring a traveling state of a host vehicle, and a sliding mode control using a target sliding mode surface including a target traveling state. A first traveling control step of controlling the traveling of the own vehicle so as to follow the preceding vehicle preceding the vehicle, and controlling the traveling of the own vehicle until the traveling state of the own vehicle converges on the target sliding mode surface. A second traveling control step for setting a provisional sliding mode surface based on the traveling state of the vehicle measured in the traveling state measuring step, and the setting step. In the sliding mode control using the temporary sliding mode surface set in step 1, the auxiliary traveling control step of controlling the traveling of the own vehicle is set in the setting step. Until the sliding mode surface of the temporary converges to a sliding mode surface of the target was carried out repeatedly.

  Such a traveling control method sets the provisional sliding mode surface based on the traveling state of the vehicle until the provisional sliding mode surface converges on the target sliding mode surface, and uses the provisional sliding mode surface. Since the running mode of the host vehicle is controlled by the sliding mode control, the driving speed of the host vehicle is controlled more rapidly than in the case where the host vehicle is controlled so that the running state of the host vehicle is included in the target sliding mode surface. Deceleration can be reduced. Therefore, the above traveling control method can reduce the sudden acceleration / deceleration and control the host vehicle to the target inter-vehicle distance during the follow-up traveling control using the sliding mode control.

  The travel control device and the travel control method according to the present invention can control the host vehicle to a target inter-vehicle distance by reducing rapid acceleration / deceleration when performing follow-up travel control using the sliding mode control.

It is a block diagram showing composition of a running control device in an embodiment. It is a figure for demonstrating the technique in which the driving | running state of the own vehicle is put on a target sliding mode surface, when a collision with a preceding vehicle is not expected in the said driving | running control apparatus. FIG. 4 is a diagram for explaining a method of placing the traveling state of the host vehicle on a target sliding mode surface when a collision with a preceding vehicle is expected in the traveling control device. It is a flow chart which shows operation of the above-mentioned run control device.

  Hereinafter, one or more embodiments of the present invention will be described with reference to the drawings. However, the scope of the invention is not limited to the disclosed embodiments. It should be noted that in each of the drawings, the components denoted by the same reference numerals indicate the same components, and the description thereof will be appropriately omitted. In the present specification, reference numerals without suffixes are used for generic names, and reference numerals with suffixes are used when referring to individual components.

  The running control device in the embodiment is a running mode measuring unit that measures a running state of the own vehicle, and a sliding mode control using a target sliding mode surface including a running state of the target. A first travel control unit that controls the travel of the own vehicle so as to follow, and a second travel control unit that controls the travel of the own vehicle until the traveling state of the own vehicle converges on the target sliding mode surface. With. Then, in the present embodiment, the second traveling control unit is configured to perform a setting process for setting a temporary sliding mode surface based on the traveling state of the host vehicle measured by the traveling state measuring unit, and the setting. In the sliding mode control using the temporary sliding mode surface set in the section, the auxiliary traveling control section for performing auxiliary traveling control for controlling the traveling of the own vehicle, and the temporary sliding mode surface set in the setting section A repeating unit that causes the setting unit and the auxiliary traveling control unit to repeatedly perform each of the setting process and the auxiliary traveling control until the target sliding mode surface is converged. Hereinafter, such a travel control device will be described more specifically.

  FIG. 1 is a block diagram showing a configuration of a travel control device in the embodiment. FIG. 2 is a diagram for explaining a method of placing the traveling state of the host vehicle on the target sliding mode surface when the collision with the preceding vehicle is not expected in the traveling control device. FIG. 3 is a diagram for explaining a method of placing the traveling state of the host vehicle on the target sliding mode surface when the collision with the preceding vehicle is expected in the traveling control device. 2 and 3, the inter-vehicle distance from the preceding vehicle to the own vehicle and the relative speed (relative vehicle speed) of the own vehicle to the preceding vehicle are coordinate axes, and the rear end position of the preceding vehicle is the origin 0 of the inter-vehicle distance. The coordinate space is shown.

  The traveling control device CTS according to the embodiment includes, for example, as shown in FIG. 1, a traveling state measuring unit 1, a control processing unit 2, and a storage unit 3. Further, in the present embodiment, a sliding mode control is performed first. A power unit 4 and a braking unit 5 are provided in order to realize the traveling operation of the vehicle that travels so as to follow the vehicle.

  The traveling state measuring unit 1 is a device that is connected to the control processing unit 2 and measures the traveling state of the host vehicle under the control of the control processing unit 2. The traveling state measuring unit 1 outputs the measured traveling state of the own vehicle to the control processing unit 2. The traveling state may be any fishing amount if necessary in order to control the follow-up traveling to follow the preceding vehicle in the sliding mode control, and the traveling state measuring unit is a device capable of measuring the physical quantity. Any device may be used as long as it is available. In one example, in the present embodiment, the traveling state is the inter-vehicle distance and the relative speed of the host vehicle with respect to the preceding vehicle (the inter-vehicle distance from the preceding vehicle to the own vehicle and the relative speed of the own vehicle with respect to the preceding vehicle (relative vehicle speed)). Is. For this reason, the traveling state measurement unit 1 is configured to include a radar device because it can measure the inter-vehicle distance and the relative speed, for example, one unit can measure the inter-vehicle distance and the relative speed. ..

  The radar device detects the target object by transmitting a predetermined transmission wave and receiving a reflected wave of the transmission wave reflected by the target object, and measures the direction of the target object and the distance to the target object. It is a device that does. Then, the radar device also obtains the relative speed of the object with respect to the own vehicle based on the Doppler shift of the reflected wave with respect to the transmitted wave. In the present embodiment, for example, the radar device is provided at the front end of the vehicle and measures an object in front of the vehicle within a predetermined object range. In one example, for example, the radar device transmits a millimeter wave band transmission wave while scanning the transmission wave in a target range, a reception section that receives a reflected wave of the transmission wave reflected by an object, and the transmission wave. And a signal processing unit that obtains the position of the object by obtaining the direction of the object and the distance to the object based on the reflected wave. The signal processing unit obtains the direction of the object from the transmission direction of the transmission wave in the scanning of the target range, based on the time difference between the transmission timing of the transmission wave and the reception timing of the reflected wave, up to the object Is calculated (TOF (Time-Of-Flight) method).

  The radar device is not limited to such a configuration and may be a radar device of an appropriate type. For example, the radar device may be a laser radar device that uses laser light instead of the millimeter wave band, and the radar device includes a plurality of receiving antennas and the reflected waves received by the plurality of receiving antennas. It may be a device that obtains the direction of the object from the phase difference.

  The traveling state measuring unit 1 that measures the inter-vehicle distance and the relative speed is not limited to the radar device and may be another type of measuring device. For example, the traveling state measuring unit 1 may include a distance image sensor, obtain the inter-vehicle distance from the distance image, and obtain the relative speed from the change over time. Alternatively, for example, the traveling state measuring unit 1 is configured to include a so-called stereo camera, obtains the inter-vehicle distance by obtaining the parallax from a pair of images generated by the stereo camera, and obtains the relative speed from the change over time. Good. The traveling state measuring unit 1 may be configured to include two devices, a first measuring device that measures the inter-vehicle distance and a second measuring device that measures the relative speed. For example, the traveling state measuring unit 1 may include a distance image sensor (or stereo camera) that measures the inter-vehicle distance and a Doppler sensor that measures the relative speed.

  The power unit 4 is a device that is connected to the control processing unit 2 and that generates power for driving (moving) the vehicle under the control of the control processing unit 2. The power generated by the power unit 4 is transmitted to the drive wheels via a power transmission mechanism that transmits power to rotate the drive wheels. The power unit 4 is configured to include, for example, an engine, a motor, a prime mover such as a hybrid device thereof, and an accessory device thereof.

  The braking unit 5 is a device that is connected to the control processing unit 2 and applies a braking force to the vehicle according to the control of the control processing unit 2 to decelerate the vehicle. The braking unit 5 can stop the vehicle as a result of decelerating the vehicle, and can also keep the vehicle stopped as a result of continuously applying the braking force while the vehicle is stopped. The braking unit 5 is configured to include, for example, a brake device such as a disc brake and a regenerative brake and its accessory.

  By controlling each of the power unit 4 and the braking unit 5, the vehicle acceleration is adjusted, the vehicle speed (vehicle speed) is adjusted, the relative speed with respect to the preceding vehicle is adjusted, and the inter-vehicle distance with respect to the preceding vehicle is adjusted. It

  The storage unit 3 is a circuit which is connected to the control processing unit 2 and stores various predetermined programs and various predetermined data under the control of the control processing unit 2. For the various predetermined programs, for example, a control program for controlling the respective units 1, 3 to 5 of the traveling control device CTS according to the functions of the respective units, and a target sliding mode surface including a target traveling state are used. In the sliding mode control, the first traveling control program for controlling the traveling of the own vehicle so as to follow the preceding vehicle preceding the own vehicle, and until the traveling state of the own vehicle converges on the target sliding mode surface. A control processing program such as a second traveling control program for controlling traveling of the own vehicle is included. The second traveling control program includes a setting program for performing a setting process for setting a temporary sliding mode surface based on the traveling state of the vehicle measured by the traveling state measuring unit 1, and a temporary program set by the setting program. In the sliding mode control using the sliding mode surface of, the auxiliary traveling control program for performing the auxiliary traveling control for controlling the traveling of the own vehicle, or the temporary sliding mode surface set by the setting program is the target sliding mode surface. It includes a repetitive program that causes the setting program and the auxiliary traveling control program to repeatedly perform the setting process and the auxiliary traveling control, respectively. The various types of predetermined data include information indicating a target sliding mode surface, a target inter-vehicle distance, a target relative speed (usually 0 (zero)), and various determination thresholds for executing each program. It includes necessary data. The storage unit 3 includes, for example, a ROM (Read Only Memory) which is a non-volatile storage element and an EEPROM (Electrically Erasable Programmable Read Only Memory) which is a rewritable non-volatile storage element. The storage unit 3 includes a RAM (Random Access Memory) or the like serving as a working memory of the so-called control processing unit 2 that stores data and the like generated during execution of the predetermined program.

  The control processing unit 2 controls the respective units 1, 3 to 5 of the travel control device CTS according to the functions of the respective units, and in the sliding mode control, the control processing unit 2 of the host vehicle follows the preceding vehicle preceding the host vehicle. It is a circuit for controlling traveling. The control processing unit 2 includes, for example, a CPU (Central Processing Unit) and its peripheral circuits. The control processing unit 2 functionally includes a control unit 21, a first traveling control unit 22, and a second traveling control unit 23 by executing the control processing program.

  The control unit 21 controls the respective units 1, 3 to 5 of the travel control device CTS according to the functions of the respective units, and is responsible for overall control of the travel control device CTS.

  The first traveling control unit 22 is a sliding mode control using a sliding mode surface of a preset target including a traveling state of a preset target, and is configured to follow the preceding vehicle preceding the host vehicle. It controls the traveling of the own vehicle. The first traveling control unit 22 converges the inter-vehicle distance and the relative speed to the equilibrium point where the target inter-vehicle distance and the relative speed is 0 while restraining the inter-vehicle distance and the relative speed on the target sliding mode surface. Each of the power unit 4 and the braking unit 5 is controlled so as to cause it. More specifically, the first traveling control unit 22 determines the difference (deviation) between the traveling state of the host vehicle (inter-vehicle distance and relative speed in this embodiment) measured by the traveling state measuring unit 1 and the target sliding mode surface. In the present embodiment, the inter-vehicle distance deviation and the relative speed deviation are obtained, and both or one of the power unit 4 and the braking unit 5 is controlled so that the obtained difference becomes zero.

  The second traveling control unit 23 controls the traveling of the host vehicle based on the traveling state of the host vehicle measured by the traveling state measuring unit 1 until the traveling state of the host vehicle converges on the target sliding mode surface. To control. To this end, for example, the second traveling control unit 23 functionally includes a setting unit 231, an auxiliary traveling control unit 232, and a repeating unit 233.

  The setting unit 231 performs a setting process for setting a temporary sliding mode surface based on the running state of the host vehicle measured by the running state measuring unit 1. More specifically, the setting unit 231 is parallel to the target sliding mode surface and includes a parallel surface including the traveling state of the host vehicle measured by the traveling state measuring unit 1 and the target sliding mode surface. In between, a provisional sliding mode surface is set parallel to the target sliding mode surface. More specifically, the setting unit 231 is parallel to the target sliding mode surface, and is preset based on the inter-vehicle distance measured by the traveling state measuring unit 1 and the relative speed measured by the traveling state measuring unit 1. A second parallel plane that passes through a coordinate point having a relative velocity close to the target sliding mode surface by a predetermined value (first predetermined value) is set as a temporary sliding mode surface.

  For example, as shown in FIG. 2, the position Pp of the rear end of the preceding vehicle VCp (the portion of the preceding vehicle VCp that reflects the transmission wave emitted from the radar device as an example of the running state measuring unit 1) is set as the coordinate origin Pp. When (0, 0) is set and an XY Cartesian coordinate system having vehicle-to-vehicle distance CVs of preceding vehicle VCp and relative speed Y as coordinate axes is set, the target sliding mode plane is a preset predetermined mode. It is expressed by a predetermined function set in advance that passes through a point (target point) Pt representing the target traveling state where the target inter-vehicle distance Lx and the relative speed is 0 (zero). In the example shown in FIG. 2, the target sliding mode surface SPt has an inclination (change amount of relative speed with respect to change amount of inter-vehicle distance, change amount of relative speed / change amount of relative speed / This is a straight line having a change amount of the inter-vehicle distance) α and passing through the target point Pt (Lx, 0), and the inter-vehicle distance X of the own vehicle VCs with respect to the preceding vehicle VCp measured by the traveling state measuring unit 1 is xs. Then, when the relative speed Y is ys, the setting unit 231 is parallel to the target sliding mode surface SPt and is a parallel plane (including the traveling state of the host vehicle measured by the traveling state measuring unit 1). The first parallel plane, in the example shown in FIG. 2, the inter-vehicle distance xs and the relative speed ys measured by the traveling state measuring unit 1 (straight line) passing through the point Ps (xs, ys) SPs and the target Sliding mode surface S A provisional sliding mode surface SPi is set parallel to the target sliding mode surface SPt between t and t. More specifically, the setting unit 231 is parallel to the target sliding mode surface SPt and is a running state measuring unit. From the inter-vehicle distance xs measured in 1 and the relative speed ys measured in the running state measuring unit 1, a relative speed ys−Δy = close to the target sliding mode surface SPt by a first predetermined value Δy set in advance. A second parallel plane (auxiliary parallel plane) SPa passing through the coordinate point Pi (xs, ya) of ya is set as a temporary sliding mode plane SPi (SPa → SPi, Pa → pi, ya → yi). The predetermined value Δy is a control cycle (will be described later) that is repeatedly executed until the provisional sliding mode surface SPi converges on the target sliding mode surface SPt. This is the amount by which the provisional sliding mode surface SPi is brought closer to the target sliding mode surface SPt in one control cycle in (following traveling control control cycle), and is set appropriately in consideration of, for example, riding comfort. In the case where the vehicle speed of the preceding vehicle VCp is constant during convergence, the provisional sliding mode surface SPi approaches the target sliding mode surface SPt by the first predetermined value Δy in each control cycle.

  Here, as in the example shown in FIG. 2, by substituting the relative speed 0 into the inter-vehicle distance (the function representing the temporary sliding mode surface SPi) obtained from the temporary sliding mode surface SPi (auxiliary parallel surface SPa → SPi). Is a positive value larger than 0, even if the traveling of the host vehicle VCs is controlled by the sliding mode control using the provisional sliding mode surface SPi, the host vehicle VCs is ahead in this situation. It is considered that there is no possibility of collision with the vehicle VCp. However, as shown in FIG. 3, when the inter-vehicle distance obtained from the temporary sliding mode surface SPi is a value of 0 or less (0 or a negative value), sliding mode control using the temporary sliding mode surface SPi is performed. When the traveling of the host vehicle VCs is controlled, it is considered that the host vehicle VCs may collide with the preceding vehicle VCp. Therefore, in the present embodiment, when the inter-vehicle distance obtained from the second parallel surface (auxiliary parallel surface) SPa is 0 or less, the setting unit 231 is parallel to the target sliding mode surface SPt and the inter-vehicle distance is 0. Then, a provisional sliding mode surface SPi is set on the side of the target sliding mode surface SPt from the third parallel surface (collision limit parallel surface) SPm that passes through the point where the relative speed is 0. More specifically, the setting unit 231 is parallel to the target sliding mode surface SPt and the inter-vehicle distance is 0 when the inter-vehicle distance obtained from the second parallel surface (auxiliary parallel surface) SPa is 0 or less. A fourth parallel surface SPe closer to the target sliding mode surface SPt by a predetermined value (second predetermined value) Le set in advance from the third parallel surface (collision limit parallel surface) SPm passing through the point where the relative speed is 0, It is set as a temporary sliding mode surface SPi (SPe → SPi). In the example shown in FIG. 3, the second predetermined value Le is set to the inter-vehicle distance X, the fourth parallel surface SPe is parallel to the target sliding mode surface SPt, and the inter-vehicle distance is the second predetermined value. It is a surface that passes through the point Le (escape point) Pe (Le, 0) where the value is Le and the relative speed is 0. When the sliding mode control is performed on the collision limit parallel surface, the inter-vehicle distance also becomes 0 at the time when the relative speed becomes 0, and the host vehicle VCs collides (contacts) with the preceding vehicle VCp. It is a sliding mode surface that is parallel to the target sliding mode surface, which is the limit to be stored. Note that FIG. 3 illustrates a case where the second parallel surface (auxiliary parallel surface) SPa matches the third parallel surface (collision limit parallel surface) SPm. Of course, although not shown, the second parallel plane (auxiliary parallel plane) SPa may not coincide with the third parallel plane (collision limit parallel plane) SPm.

  The auxiliary traveling control unit 232 is a sliding mode control using the temporary sliding mode surface set by the setting unit 231, and performs auxiliary traveling control for controlling the traveling of the own vehicle. That is, the auxiliary traveling control unit 232, like the first traveling control unit 22, restrains the inter-vehicle distance and the relative speed on the tentative sliding mode surface, and the target inter-vehicle distance on the tentative sliding mode surface (temporary The inter-vehicle distance and the relative speed are controlled so that the inter-vehicle distance and the relative speed converge to an equilibrium point at which the relative speed is 0.

  The repeating unit 233 repeats the setting process and the auxiliary traveling control respectively to the setting unit 231 and the auxiliary traveling control unit 232 until the temporary sliding mode surface set by the setting unit 231 converges on the target sliding mode surface. It is something to do. More specifically, the repeating unit 233 determines whether the temporary sliding mode surface set by the setting unit 231 converges on the target sliding mode surface, and as a result of this determination, the temporary sliding mode surface is determined. Is not converged on the target sliding mode surface, the setting process and the auxiliary traveling control are repeatedly performed by the setting unit 231 and the auxiliary traveling control unit 232, respectively, while the determination result indicates that the temporary sliding is performed. When the mode surface is converged on the target sliding mode surface, this repetition is ended. The first traveling control unit 22 performs sliding mode control using the target sliding mode surface. In the determination of the convergence, for example, a correlation value between the provisional sliding mode surface and the target sliding mode surface is obtained, and it is determined whether the correlation value is equal to or more than a predetermined threshold value (first threshold value) set in advance. It is determined whether the temporary sliding mode surface is converged on the target sliding mode surface. It is assumed that the larger the correlation value, the more the two are correlated. In the present embodiment, since the temporary sliding mode surface is parallel to the target sliding mode surface, the difference between the temporary sliding mode surface and the target sliding mode surface (the temporary sliding mode surface and the target in the XY orthogonal coordinate system Distance from the sliding mode surface of the tentative sliding mode surface is determined, and the provisional sliding mode surface converges on the target sliding mode surface depending on whether or not this difference is less than or equal to a predetermined threshold value (second threshold value) set in advance. Is determined.

  Next, the operation of this embodiment will be described. FIG. 4 is a flowchart showing the operation of the traveling control device.

  When the host vehicle VCs starts to operate and the switch for turning on and off the follow-up traveling control (not shown) is turned on, such a traveling control device CTS executes necessary initialization of each unit and starts its operation. By executing the control processing program, the control processing unit 2 functionally includes the control unit 21, the first traveling control unit 22, and the second traveling control unit 23, and the second traveling control unit 23 includes the setting unit. 231, the auxiliary traveling control unit 232, and the repeating unit 233 are functionally configured. Then, the control processing unit 2 operates as follows in one control cycle of the control cycle of the follow-up running control that is repeatedly executed at predetermined time intervals, so that the preceding vehicle VCp preceding the own vehicle VCs is operated. The traveling of the host vehicle VCs is controlled so as to follow.

  In FIG. 4, the control processing unit 2 first acquires the traveling state of the host vehicle by the traveling state measuring unit 1 (S1). In the present embodiment, the control processing unit 2 acquires the inter-vehicle distance and the relative speed of the own vehicle with respect to the preceding vehicle with the radar device of the example. Here, in the present embodiment, the control processing unit 2 detects a moving object (moving body) in front as a preceding vehicle, but the traveling control device CTS further captures an image that generates a front image. A device (camera) may be further provided, and based on the image, it may be verified whether or not the moving object in the front is a vehicle.

  Next, the control processing unit 2 may obtain a temporary sliding mode surface parallel to the target sliding mode surface based on the traveling state of the host vehicle measured by the traveling state measuring unit 1, but in the present embodiment, collision is possible. Since the presence / absence of the property is determined, the control processing unit 2 then causes the setting unit 231 of the second traveling control unit 23 to set the target sliding mode surface based on the traveling state of the host vehicle measured by the traveling state measuring unit 1. An auxiliary parallel plane parallel to is obtained (S2). More specifically, as described above with reference to FIGS. 2 and 3, the first parallel to the target sliding mode surface SPt and including the traveling state of the host vehicle measured by the traveling state measuring unit 1. An auxiliary parallel plane SPa parallel to the target sliding mode surface SPt is obtained between the surface (straight line in FIGS. 2 and 3) SPs and the target sliding mode surface SPt. More specifically, a first preset value that is parallel to the target sliding mode surface SPt and is preset from the inter-vehicle distance xs measured by the traveling state measuring unit 1 and the relative speed ys measured by the traveling state measuring unit 1. The auxiliary parallel surface SPa passing through the coordinate point Pa (xs, ya) of the relative velocity ya (= ys-Δy) close to the target sliding mode surface SPt by the predetermined value Δy is obtained.

  Next, the control processing unit 2 determines by the setting unit 231 whether or not the own vehicle may collide with the preceding vehicle when the obtained auxiliary parallel plane is a temporary sliding mode plane (S3). ). More specifically, the setting unit 231 determines whether or not the host vehicle may collide with the preceding vehicle by determining whether or not the inter-vehicle distance obtained from the auxiliary parallel plane is 0 or less. .. As a result of this determination, when it is determined that the inter-vehicle distance obtained from the auxiliary parallel plane is not less than 0 and there is no risk of the host vehicle colliding with the preceding vehicle (No), the setting unit 231 sets this auxiliary parallel plane. It is set as a temporary sliding mode surface (S4), and then the process S6 is executed. In the example of FIG. 2, the auxiliary parallel plane SPa is set as the provisional sliding mode plane SPi (SPa → SPi). On the other hand, when the inter-vehicle distance obtained from the auxiliary parallel plane is 0 or less and it is determined that the host vehicle may collide with the preceding vehicle (Yes), the setting unit 231 determines that the vehicle is in parallel with the target sliding mode plane. Then, a provisional sliding mode surface is set to the target sliding mode surface side from the collision limit parallel surface that passes through the point where the inter-vehicle distance is 0 and the relative speed is 0 (S5), and then the processing S6 is executed. Run. More specifically, the setting unit 231 is parallel to the target sliding mode surface, and the target sliding mode is the second predetermined value from the collision limit parallel surface that passes through the point where the inter-vehicle distance is 0 and the relative speed is 0. The fourth parallel plane close to the plane is set as a temporary sliding mode plane. In the example of FIG. 3, the fourth parallel surface SPe closer to the target sliding mode surface SPt by the second predetermined value Le than the collision limit parallel surface SPm is set as the temporary sliding mode surface SPi (SPe → SPi).

  In process S6, which is performed after performing process S4 or after performing process S5, the control processing unit 2 causes the repeating unit 233 of the second traveling control unit 23 to perform the target sliding mode plane sliding. It is determined whether or not the mode plane is converged. As a result of this determination, when the provisional sliding mode surface does not converge to the target sliding mode surface (No), the control processing unit 2 causes the auxiliary traveling control unit 232 of the second traveling control unit 23 to set the setting unit. With the sliding mode control using the temporary sliding mode surface set in 231, the auxiliary traveling control for controlling the traveling of the host vehicle is performed (S7), and the present processing in the current control cycle is ended. On the other hand, as a result of the determination, when the provisional sliding mode surface is converged on the target sliding mode surface (Yes), the control processing unit 2 causes the first traveling control unit 22 to determine the target sliding mode surface. With the sliding mode control used, traveling control is performed to control the traveling of the host vehicle so as to follow the preceding vehicle (S8), and the present processing in this control cycle ends.

  As described above, the traveling control device CTS and the traveling control method implemented therein according to the present embodiment are based on the traveling state of the host vehicle until the provisional sliding mode surface converges on the target sliding mode surface. By setting a temporary sliding mode surface and controlling the traveling of the own vehicle by the sliding mode control using the temporary sliding mode surface, the traveling state of the own vehicle is included in the target sliding mode surface. Compared with the case where the traveling of the host vehicle is controlled, sudden acceleration / deceleration can be reduced. Therefore, the traveling control device CTS and the traveling control method can control the own vehicle to the target inter-vehicle distance by reducing the rapid acceleration / deceleration during the follow-up traveling control using the sliding mode control.

  Since the traveling control device CTS and the traveling control method set the temporary sliding mode surface in parallel to the target sliding mode surface, the sliding mode control using the temporary sliding mode surface and the target sliding mode surface are used. In both of the sliding mode control, the same acceleration can be controlled. Therefore, the traveling control device can control the own vehicle to the target inter-vehicle distance by decelerating at a substantially constant speed or increasing the speed at a substantially constant speed.

  Note that, in the above-described embodiment, the operation shown in FIG. 4 is performed in each control cycle in the control cycle of the follow-up running control, but it is determined in step S6 that the temporary sliding mode surface has converged to the target sliding mode surface. 4 is ended, and in each control cycle thereafter, the first traveling control unit 22 performs the sliding mode control using the target sliding mode surface so as to follow the preceding vehicle. The travel control for controlling the travel of the vehicle may be performed. In this case, when the traveling state of the preceding vehicle is monitored (monitored) and the traveling state of the preceding vehicle deviates from the traveling state at the time of determining the convergence to a predetermined range or more (for example, the relative speed is The traveling control device CTS restarts the operation shown in FIG. 4 when the relative speed at the time of determining the convergence exceeds a predetermined value (third predetermined value) set in advance).

  Further, in the above-described embodiment, the setting unit 231 obtains the collision margin time, which is the time until the own vehicle collides with the preceding vehicle, based on the traveling state of the own vehicle measured by the traveling state measuring unit 1. The temporary sliding mode surface may be set based on the obtained collision margin time. More specifically, for example, the setting unit 231 obtains the collision margin time (= inter-vehicle distance / relative speed) from the inter-vehicle distance and the relative speed of the host vehicle with respect to the preceding vehicle, and based on the obtained collision margin time, A first predetermined value is set, the second parallel plane (auxiliary parallel plane) is set using the set first predetermined value, and provisional sliding is performed based on the set auxiliary parallel plane as described above. Set the mode plane. The correspondence relationship between the collision margin time and the first predetermined value is appropriately set in advance and stored in the storage unit 3 as one of the various predetermined data. In this case, if the first predetermined value corresponding to the collision margin time is set so as not to collide with each other, the processes S3 and S5 related to the collision determination described above can be omitted, and the second parallel plane (auxiliary parallel plane) can be omitted. ) Is set as the provisional sliding mode surface (S4), and then the process S6 is executed. Since such a traveling control device CTS sets the temporary sliding mode surface based on the collision margin time, the time until the temporary sliding mode surface converges to the target sliding mode surface in consideration of the collision margin time. Can be adjusted.

  Then, in such a case, the setting unit 231 may set the provisional sliding mode surface so that the shorter the calculated collision margin time is, the closer to the target sliding mode surface. More specifically, the correspondence relationship between the collision margin time and the first predetermined value is set such that the shorter the collision margin time, the larger the first predetermined value. Such a travel control device CTS sets a provisional sliding mode surface so that the shorter the collision margin time is, the closer it is to the target sliding mode surface. Therefore, when the collision margin time is relatively short, a collision may occur. The temporary sliding mode surface can be converged to the target sliding mode surface in a relatively short time while avoiding the above, while the temporary sliding mode surface is gradually increased in a relatively long time when the collision margin time is relatively long. The mode plane can be converged to the target sliding mode plane.

  In order to represent the present invention, the present invention has been described above appropriately and sufficiently through the embodiments with reference to the drawings, but those skilled in the art can easily modify and / or improve the above embodiments. It should be recognized that this is possible. Therefore, unless a modification or improvement performed by a person skilled in the art is at a level that departs from the scope of rights of the claims recited in the claims, the modification or the improvement is covered by the scope of rights of the claims. Is understood to be included in.

CTS traveling control device 1 traveling state measuring unit 2 control processing unit 3 storage unit 4 power unit 5 braking unit 21 control unit 22 first traveling control unit 23 second traveling control unit 231 setting unit 232 auxiliary traveling control unit 233 repeating unit

Claims (6)

A running condition measuring unit that measures the running condition of the vehicle,
A first traveling control unit that controls traveling of the own vehicle so as to follow a preceding vehicle preceding the own vehicle by sliding mode control using a target sliding mode surface including a target traveling state;
A second traveling control unit that controls traveling of the own vehicle until the traveling state of the own vehicle converges on the target sliding mode surface,
The second traveling control unit,
A setting unit for performing a setting process for setting a temporary sliding mode surface based on the traveling state of the vehicle measured by the traveling state measuring unit;
In a sliding mode control using a temporary sliding mode surface set by the setting unit, an auxiliary traveling control unit that performs auxiliary traveling control for controlling traveling of the own vehicle,
A repeating unit that causes the setting unit and the auxiliary traveling control unit to repeatedly perform the setting process and the auxiliary traveling control, respectively, until the provisional sliding mode surface set by the setting unit converges on the target sliding mode surface. With and
Travel control device. The setting unit is parallel to the target sliding mode surface, and between the parallel surface including the traveling state of the vehicle measured by the traveling state measuring unit and the target sliding mode surface, the target Parallel to the sliding mode surface of the, set the temporary sliding mode surface,
The travel control device according to claim 1. The setting unit obtains a collision margin time which is a time until the own vehicle collides with the preceding vehicle, based on the traveling state of the own vehicle measured by the traveling state measurement unit, and the obtained collision margin time. Based on, set the temporary sliding mode surface,
The travel control device according to claim 1 or 2. The provisional sliding mode surface is set so that the shorter the calculated collision margin time is, the closer to the target sliding mode surface.
The travel control device according to claim 3. The traveling state is an inter-vehicle distance and a relative speed of the host vehicle with respect to the preceding vehicle,
The target sliding mode surface is represented by a predetermined function passing through a point having a predetermined target inter-vehicle distance and a relative speed of 0, which is set in a coordinate space having the inter-vehicle distance and the relative speed as coordinate axes. ,
The setting unit is parallel to the sliding mode surface of the target, the inter-vehicle distance measured by the running state measurement unit, and the sliding of the target by a predetermined value from the relative speed measured by the running state measurement unit. The second parallel plane passing through the coordinate point of the relative velocity close to the mode plane is set as the temporary sliding mode plane,
The travel control device according to any one of claims 2 to 4. A running condition measuring step for measuring the running condition of the host vehicle,
A first traveling control step of controlling traveling of the own vehicle so as to follow a preceding vehicle preceding the own vehicle by sliding mode control using a target sliding mode surface including a target traveling state;
A second traveling control step of controlling traveling of the own vehicle until the traveling state of the own vehicle converges on the target sliding mode surface,
The second traveling control step includes a setting step of setting a temporary sliding mode surface based on the traveling state of the host vehicle measured in the traveling state measuring step, and a temporary sliding mode surface set in the setting step. With the sliding mode control used, the auxiliary traveling control step of controlling the traveling of the own vehicle is repeatedly performed until the temporary sliding mode surface set in the setting step converges to the target sliding mode surface,
Driving control method.

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