JP4766152B2 - Vehicle travel control device - Google Patents

Description

  The present invention relates to a vehicle travel control device that generates a travel route from which a vehicle will travel, generates a speed pattern according to the travel route, and controls the travel of the vehicle based on the travel route and the speed pattern. is there.

  A technology for generating an optimal travel locus of a vehicle and automatically traveling the vehicle using the travel locus has been developed. For example, there is a paper on theoretical research on the shortest time cornering method described in Non-Patent Document 1 below. In this paper, it is an ideal trajectory calculation method using an optimization method. The corner transit time is set as an evaluation function, and the optimization method is used to minimize this evaluation function. The position and speed of the vehicle are calculated, and a travel locus and speed pattern for the vehicle to pass through the corner in the shortest time are generated.

Tetsuhiko Fujioka, Daisho Emori: Automobile Engineering Society Proceedings Vol. 24, no. 3, July 1993, P106-P111 "Theoretical Study on the Shortest Time Cornering Method"

  In the above-described conventional technology, since the convergence calculation in which the position (trajectory) or speed of the vehicle is changed and the calculation is repeatedly performed while observing the increase / decrease as an evaluation formula is fundamental, the vehicle travels with high accuracy. When generating a trajectory and a speed pattern, the number of calculations increases and the calculation time becomes long. Therefore, a high-precision and expensive control device is required for mounting on a vehicle.

  The present invention is for solving such a problem, and generates a speed pattern according to a travel route in a short time, and enables vehicle travel control that enables appropriate travel control of the vehicle based on the speed pattern. An object is to provide a control device.

In order to solve the above-described problems and achieve the object, a vehicle travel control device of the present invention generates a speed pattern along a target travel route and controls the travel of the vehicle based on the speed pattern. In the apparatus, first speed state correction means for executing a speed state correction process from the start position of the travel control on the target travel route toward the end position of the travel control, and travel from the end position of the travel control on the target travel route Second speed state correction means for executing speed state correction processing toward the control start position , wherein the first speed state correction means corrects the acceleration-side speed state to the low speed side, and The two-speed state correcting means corrects the speed state on the deceleration side to the low speed side .

In the vehicle travel control device of the present invention, a travel route dividing unit that divides the target travel route at a predetermined interval is provided, and the first speed state correcting unit and the second speed state correcting unit are provided for each divided region. The speed state is corrected, the speed states of the divided adjacent areas are compared, and the speed state of the area with the highest speed is corrected to the low speed side.

In the vehicle travel control device of the present invention, a travel route dividing unit that divides the target travel route at a predetermined interval is provided, and the first speed state correcting unit and the second speed state correcting unit are provided for each divided region. The speed state is corrected , the acceleration or deceleration of each divided adjacent area is compared, and the highest acceleration or deceleration is corrected to the lower side .

In the vehicle travel control device of the present invention, the first speed state correcting unit and the second speed state correcting unit perform correction processing so that the acceleration or deceleration of an adjacent region is equal to or less than an upper limit value . .

  In the vehicle travel control device of the present invention, the first speed state correcting unit and the second speed state correcting unit calculate an addition vector of acceleration or deceleration and lateral acceleration in an adjacent region, The speed is corrected based on the friction circle in the region.

  In the vehicle travel control device of the present invention, the first speed state correcting unit and the second speed state correcting unit correct the speed of the adjacent region to the low speed side so that the addition vector does not exceed the friction circle in each region. It is characterized by processing.

In the vehicle travel control apparatus according to the present invention, the first speed state correcting unit and the second speed state correcting unit calculate a jerk of an adjacent region, and compare the jerk with a preset limit value. The speed is corrected so as to be smaller than the limit value .

In the vehicle travel control device of the present invention, the first speed state altering means and the second speed state correcting means, wherein when the speed change of the adjacent regions are represented in graph form a concave shape, the speed is high and The correction processing is characterized in that the speed state of the area on the traveling direction side is corrected to the low speed side.

In the vehicle travel control device of the present invention, the first speed state altering means and the second speed state correcting means, wherein when the speed change of the adjacent regions are represented in graph form a convex shape, the speed is high and The speed state of the intermediate area of the adjacent areas is corrected to the low speed side.

  In the vehicle travel control device of the present invention, the limit value is set according to the shape of the target travel route.

  In the vehicle travel control device of the present invention, the first speed state correcting means and the second speed state correcting means perform speed state correction processing using the vehicle as a mass point model.

  In the vehicle travel control apparatus according to the present invention, the first speed state correcting unit and the second speed state correcting unit may perform the lateral force state using the vehicle as a rigid model after completing the speed state correcting process for each divided area. It is characterized in that correction processing is performed.

According to the vehicle travel control device of the present invention, the first speed state correcting means for executing the speed state correction process from the start position of the travel control on the target travel route toward the end position of the travel control, and the travel on the target travel route Second speed state correction means for executing speed state correction processing from the control end position toward the travel control start position is provided , and the first speed state correction means corrects the speed state on the acceleration side to the low speed side. Then, the second speed state correcting means corrects the speed state on the deceleration side to the low speed side, so that a speed pattern corresponding to the travel route is generated in a short time, and an appropriate travel control of the vehicle is performed based on this speed pattern. Can be made possible.

FIG. 1 is a schematic configuration diagram illustrating a vehicle travel control apparatus according to a first embodiment of the present invention. FIG. 2 is a flowchart for generating a speed pattern according to a travel route in the vehicle travel control apparatus of the first embodiment. FIG. 3 is a schematic diagram for explaining a speed pattern generation process. FIG. 4 is a schematic diagram showing a traveling course of the vehicle. FIG. 5 is a graph showing a speed pattern in steady circle turning on a traveling course. FIG. 6 is a graph showing a speed pattern obtained by adding acceleration correction to a steady circle turn on a traveling course. FIG. 7 is a graph showing a speed pattern in which acceleration correction and deceleration correction are added to steady circle turning on a traveling course. FIG. 8A is an explanatory diagram illustrating acceleration correction with respect to the speed pattern of steady circular turning. FIG. 8-2 is an explanatory diagram illustrating a speed pattern before and after acceleration correction is performed. FIG. 9 is a flowchart for generating a speed pattern corresponding to a travel route in the vehicle travel control apparatus according to the second embodiment of the present invention. FIG. 10-1 is a flowchart for generating a speed pattern according to a travel route in the vehicle travel control apparatus according to the third embodiment of the present invention. FIG. 10-2 is a flowchart for generating a speed pattern according to the travel route in the vehicle travel control apparatus according to the third embodiment of the present invention. FIG. 11 is a graph showing a speed pattern to which jerk correction is applied in a running course. FIG. 12A is an explanatory diagram illustrating jerk correction for a speed pattern. FIG. 12-2 is an explanatory diagram illustrating jerk correction for a speed pattern. FIG. 13 is a flowchart for generating a speed pattern according to the travel route in the vehicle travel control apparatus according to the fourth embodiment of the present invention. FIG. 14 is a flowchart for generating a speed pattern according to the travel route in the vehicle travel control apparatus according to the fifth embodiment of the present invention.

  Embodiments of a vehicle travel control device according to the present invention will be described below in detail with reference to the drawings. In addition, this invention is not limited by this Example.

  FIG. 1 is a schematic configuration diagram illustrating a vehicle travel control apparatus according to a first embodiment of the present invention. FIG. 2 is a flowchart for generating a speed pattern according to a travel route in the vehicle travel control apparatus according to the first embodiment. 3 is a schematic diagram for explaining a speed pattern generation process, FIG. 4 is a schematic diagram showing a traveling course of a vehicle, FIG. 5 is a graph showing a speed pattern in a steady circular turn on the traveling course, and FIG. FIG. 7 is a graph showing a speed pattern obtained by adding acceleration correction and deceleration correction to a steady circular turn on a traveling course, and FIG. FIG. 8B is an explanatory diagram illustrating the speed pattern before and after the acceleration correction is performed. FIG.

  In the vehicle travel control apparatus of this embodiment, as shown in FIG. 1, an electronic control unit (ECU) 10 includes a brake pedal sensor 11, an accelerator pedal sensor 12, a rudder angle sensor 13, and a G (acceleration) sensor. 14, a yaw rate sensor 15, a wheel speed sensor 16, a white line recognition sensor 17, and a navigation system 18 are connected.

  The brake pedal sensor 11 detects the depression amount (brake pedal stroke or depression force) of the brake pedal depressed by the driver, and outputs the detected depression amount of the brake pedal to the ECU 10. The accelerator pedal sensor 12 detects the amount of depression of the accelerator pedal (accelerator opening) depressed by the driver, and outputs the detected amount of depression of the accelerator pedal to the ECU 10. The steering angle sensor 13 detects the steering angle of the steering wheel steered by the driver, and outputs the detected steering angle to the ECU 10.

  The G (acceleration) sensor 14 detects longitudinal acceleration and lateral acceleration acting on the vehicle, and outputs each detected acceleration to the ECU 10. The yaw rate sensor 15 detects the yaw rate (lateral turning speed) generated in the vehicle, and outputs the detected yaw rate to the ECU 10. The wheel speed sensor 16 is provided on each of the four wheels of the vehicle and detects the rotational speed of each wheel, and outputs the detected rotational speed of each wheel to the ECU 10. The ECU 10 calculates the vehicle speed based on the rotational speed of each wheel.

  The white line recognition sensor 17 includes a camera and an image processing device, detects left and right white lines on both sides of the traveling lane, and outputs the detected positions (coordinates) of the left and right white lines to the ECU 10. The ECU 10 calculates a line (center line) passing through the center of the vehicle from the positions of the left and right white lines, a curve radius of the center line, and the like. The navigation system 18 is a system that performs detection of the current position of the vehicle, route guidance to a destination, and the like. In particular, the navigation system 18 reads a road shape currently running from the map database and outputs the road shape information to the ECU 10.

  Further, a throttle actuator 21, a brake actuator 22, and a steering actuator 23 are connected to the ECU 10.

  The throttle actuator 21 opens and closes the throttle valve in the electronic throttle device and adjusts the throttle opening. The ECU 10 operates the throttle actuator 21 in accordance with the engine control signal to adjust the opening of the throttle valve. To do. The brake actuator 22 adjusts the control hydraulic pressure to the wheel cylinder provided in the brake device, and the ECU 10 operates the brake actuator 22 according to the brake control signal to adjust the brake hydraulic pressure of the wheel cylinder. The steering actuator 23 applies a rotational driving force by the motor as a steering torque to the steering mechanism via the speed reduction mechanism. The ECU 10 operates the steering actuator 23 according to the steering control signal and adjusts the steering torque by the motor. To do.

  By the way, when a vehicle automatically travels along a certain road shape, it is necessary to set a target travel route and set a speed pattern in consideration of fuel consumption, passage time, safety, and the like according to the road shape. In this case, the target travel route is a travel route on which the vehicle will travel in the future, and has a curved portion (target curve travel route). The target travel route is composed of a number of parameters necessary for the travel of the vehicle, such as the vehicle position, vehicle speed, acceleration, and yaw rate.

  The vehicle travel control apparatus according to the first embodiment performs travel control from a generation unit that generates a standard speed pattern (steady circle maximum speed pattern) and a start position that executes travel control on the target travel route. The first speed state correcting means for executing the speed state correction process in the speed pattern toward the end position for executing the speed, and the speed from the end position for executing the travel control on the target travel route toward the start position for executing the travel control And a second speed state correcting means for executing a speed state correcting process in the pattern. That is, when executing the correction process, the first speed state correction unit sequentially corrects the speed state in the speed pattern in order from the start position to the end position of the process on the target travel route. Further, when executing the correction process, the second speed state correction unit corrects the speed state in the speed pattern in order from the end position of the process toward the start position on the target travel route.

  The first speed state correcting means corrects the speed state on the acceleration side, and the second speed state correcting means corrects the speed state on the deceleration side. In this case, the first speed state correcting unit and the second speed state correcting unit correct the speed state to the low speed side.

  In addition, the vehicle travel control apparatus according to the first embodiment includes a travel route dividing unit that divides the target travel route at a constant interval (distance or time), and the first speed state correcting unit and the second speed state correcting unit are divided. The speed state is corrected for each of the areas, the speed states of adjacent areas are compared, and the speed state of the high speed area is corrected to the low speed side.

  Specifically, the first speed state correcting means corrects the speed state for each of the divided areas, compares the accelerations of adjacent areas, and corrects the low speed side to suppress excess acceleration, The second speed state correcting means corrects the speed state for each of the divided areas, compares the deceleration of adjacent areas, and corrects the speed to the low speed side so as to suppress excessive deceleration.

  In the present embodiment, the standard speed pattern generating means, the first speed state correcting means, and the second speed state correcting means described above function by the ECU 10 and execute various processes.

The vehicle travel control apparatus according to the first embodiment will be described in detail. In the field of vehicle travel control dynamics, the vehicle speed V, the maximum vehicle speed V ² , the vehicle lateral acceleration Ay, the gravitational acceleration g, the tire and the road surface The following general formula (equation of motion) is established with the friction coefficient μ and the turning radius R of the road.
V ² = Ay × R
= Μ × g × R

  In the vehicle travel control device of the first embodiment, on the assumption of this equation of motion, for the purpose of maintaining safety within the tire friction circle, a travel route for the vehicle to travel from now on is generated, and a speed pattern corresponding to this travel route is generated. To do.

  First, the navigation system 18 reads the road shape of the course to be traveled from the map database, and sets the target travel route. Then, the target travel route is divided into fixed minute intervals (distances). In this case, once the speed pattern corresponding to the travel route is generated, the target travel route may be divided into fixed minute intervals (time), and processing described later may be executed.

  Next, the turning radius R of the road is calculated in a plurality of regions where the target travel route is divided at a constant minute interval, and the above-mentioned preconditions are calculated using the turning radius R and the friction coefficient μ between the tire and the road surface. The maximum speed of the vehicle in each divided area is calculated by (Equation Equation), and a steady circle maximum speed pattern is generated using a plurality of maximum speeds in each divided area. In this case, the friction coefficient μ may be estimated based on information obtained from the navigation system 18.

  When the steady circle maximum speed pattern in the target travel route is generated, acceleration between adjacent points is calculated from the travel start point to the travel end point. Here, when there is an excess of acceleration, the speed is corrected to the low speed side so that the speed at a point close to the travel end point is equal to or lower than the upper limit acceleration. In this case, the upper limit acceleration is set to a lower value of the value obtained from the running performance of the vehicle and the value protruding from the friction circle.

  Further, the deceleration between adjacent points is calculated from the travel end point toward the travel start point. Here, when there is an excess of deceleration, the speed is corrected to the low speed side so that the speed at a point close to the travel start point is not more than the upper limit deceleration. In this case, the upper limit deceleration is set to a lower value between a value obtained from the running performance of the vehicle and a value protruding from the friction circle.

  In this way, by correcting the maximum speed according to the acceleration and deceleration between the travel start point and the travel end point with respect to the steady circle maximum speed pattern, a speed pattern corresponding to the target travel route is generated. .

  Here, the generation process of the speed pattern according to the travel route in the vehicle travel control apparatus of the first embodiment will be described in detail with reference to the flowchart of FIG.

  In the speed pattern generation process according to the travel route in the vehicle travel control apparatus of the first embodiment, as shown in FIG. 2, the upper limit for the speed according to the vehicle specifications is set for the target travel route set in step S11. Generate an acceleration map. In step S12, a friction coefficient μ between the tire and the road surface is set. In this case, for example, μ = 0.6 is set on the road surface of a normal road, and when it is determined in step S13 that there is snow on the road or a frozen low μ road, step S14 is performed. For example, μ = 0.2 is set.

  In step S15, the target travel route is divided into constant minute distance intervals (for example, 1 m). Then, an array of the coordinates of each point is created in a plurality of areas into which the target travel route is divided. In this case, the coordinates (0, 0) of the travel start point are represented as x (m) to the north and y (m) to the east as coordinates (x, y). Then, a representative point in each divided area, for example, a center point in each area or an average point of a plurality of points is set as a point on the coordinates. It is assumed that the target travel route is discretely prepared as a list of coordinates (x, y) at non-uniform intervals. In that case, a general linear interpolation process is performed for each distance interval. This linear interpolation processing is because the calculation is shifted if the distance between adjacent sections is greatly different when performing adjacent point processing. If the distance between adjacent points is substantially equal, the distance is distant (for example, 10 m). It is not a big problem that the distance between sections is different.

  Specifically, as shown in FIG. 3, a target travel route B is set for a certain curve travel route A, and the target travel route B is divided into the curve travel route A along the longitudinal direction at a constant minute interval. Then, a plurality of regions C are partitioned. In this case, the intersection between the target travel route B and the first division line is set as the travel start point, the intersection between the target travel route B and the last division line is defined as the travel end point, and the travel start point and the travel end point are divided. The distance from the center position point of each area is defined as a distance L between two points described later.

  Subsequently, in step S16, a plurality of arrays of the turning radius R and the distance interval with respect to the distance from the travel start point are created in a plurality of areas into which the target travel route is divided. In this case, the turning radius R can be calculated by a mathematical calculation method for obtaining the radius of a circle passing through three general points, but the data obtained from the vehicle using the navigation system 18 includes noise. Therefore, it is desirable that the three points used in the calculation are not adjacent to each other, but those having an appropriate distance (for example, 10 m).

  In step S17, the maximum speed V of the vehicle in each divided region is calculated from the equation of motion using the turning radius R of the road and the friction coefficient μ between the tire and the road surface. Here, the initial speed and the final speed are set at the travel start point and the travel end point. If it is determined in step S18 that the maximum vehicle speed V in all the divided regions in the target travel route has been calculated, a steady circle maximum speed pattern is generated in step S19.

  That is, the steady circle maximum speed pattern as shown in FIG. 5 is generated for the traveling course as shown in FIG. This steady circle maximum speed pattern represents the maximum speed with respect to the travel distance (horizontal axis).

In steps S20 to S26, the maximum speed is corrected based on the acceleration between adjacent points from the travel start point to the travel end point with respect to the steady circle maximum speed pattern in the generated target travel route. That is, at step S20, sets the one section forward areas in running end point side from the running start point, in step S21, the maximum velocity V of the maximum speed V _n and the front region of the area (driving start point +1) _The passing time dt _n is calculated from the distance L _n between the two points of _n−1 .
dt _n = L _n / ((V _n−1 + V _n ) / 2)
Then, to calculate the acceleration A _n at this time.
_{A n = (V n -V n} -1) / dt n

In step S22, the upper limit acceleration A _max1 corresponding to the maximum speed V _n-1 is extracted from the map (maximum speed-upper limit acceleration map set according to vehicle performance), and the maximum acceleration A corresponding to the friction coefficient μ. _max2 (friction coefficient μ × gravity acceleration g) is calculated. Here, a lower numerical value of the upper limit acceleration A _max1 and the maximum acceleration A _max2 is set as the upper limit acceleration A _max .
A _max = min (A _max1 , A _max2 )

In step S23, it determines the acceleration _{A n} is whether it is less than this upper limit acceleration _{A max.} Here, when it is determined that the acceleration _An is equal to or lower than the upper limit acceleration A _max , the process proceeds to step S25, and when it is determined that the acceleration _An is greater than the upper limit acceleration A _max , the maximum speed V _n is set in step S24. Correct it.
_{V n = (V n-1} + A max × dt n)
That is, when there is an excess of acceleration, the speed is corrected to the low speed side so that the acceleration at a point close to the travel end point is not more than the upper limit acceleration.

At step S25, it determines whether the corrective action of the maximum speed V _n is completed from runner-up of the travel start point to the front point of the running end point. Here, if it is determined that the correction processing of the maximum speed V _n in all the regions has not been completed, at step S26, after setting the one section forward areas in running end point side from the treated area (point) , Steps S21 to S24 are repeated. Then, when at step S25, correction processing maximum speed V _n to the previous point of the running end point from the runner-up of the travel start point is determined to be complete, the process proceeds to step S27.

To explain the maximum speed of the correction process towards the travel end point from the running start point in detail, as shown in Figure 8-1, the maximum speed V _n-1 point and the point of its short of the maximum speed V _n when is set, it has a distance L _n between the two points. At this time, it passes seek time dt _n of the distance _{L n} between two points of a point and the maximum speed _{V n-1} of the maximum speed _{V n,} to calculate the acceleration _{A n} of the vehicle at this time. If the acceleration A _max is larger than the upper limit acceleration A _max , the maximum speed V _n is corrected. In this case, the speed increases, and the point close to the travel end point, i.e., to modify the speed of the maximum speed V _n to the low speed side. By repeating this maximum speed correction process in each divided section, the maximum speed pattern becomes smooth as shown in FIG.

Relative steady circular maximum speed pattern, by conducting correction processing maximum speed V _n toward the travel end point from the running start point, as the bold line shown in FIG. 6, at each curve road, the acceleration in each divided section The vehicle speed on the side will be corrected appropriately.

In steps S27 to S33, the maximum speed is corrected based on the deceleration between adjacent points from the travel end point to the travel start point with respect to the steady circle maximum speed pattern in the target travel route. That is, at step S27, sets the one section retracted region running start point side from the running end point, in step S28, the maximum velocity V of the maximum speed V _n and the front area of this region (running end -1) _The passing time is calculated from the distance L _n between the two points of _{n + 1} .
dt _n = L _n / ((V _n + V _{n + 1} ) / 2)
Then, to calculate the deceleration A _n at this time.
_{A n = (V n + 1} -V n) / dt n

In step S29, the maximum deceleration A _max (friction coefficient μ × gravity acceleration g) corresponding to the friction coefficient μ is calculated.

In step S30, it is determined whether or not the acceleration _An is _equal to or greater than the upper limit deceleration A _max . If it is determined that the acceleration _An is _equal to or greater than the upper limit deceleration _Amax , the process proceeds to step S32. If it is determined that the deceleration _An is smaller than the upper limit deceleration _Amax , the maximum speed is determined in step S31. to modify the V _n.
V _n = (V _{n + 1} + A _max × dt _n )
That is, when there is an excess of deceleration, the speed is corrected to the low speed side so that the deceleration at a high speed and close to the travel start point is not more than the upper limit deceleration.

In step S32, it determines whether the corrective action of the maximum speed V _n is completed before the point of running end point to the runner-up running start point. Here, if it is determined that the correction processing of the maximum speed V _n in all sections has not been completed, at step S33, after setting the one section retracted segment As a starting point side from the treated zone (point) The processes of steps S28 to S31 are repeated. Then, when at step S32, correction processing maximum speed V _n from the previous point to the runner-up of the travel start point of the travel end point is determined to be complete, the process proceeds to step S34.

Relative steady circular maximum speed pattern, by conducting correction processing maximum speed V _n toward the running start point from the running end point, as in the bold line shown in FIG. 7, in each curve road, deceleration of each divided section The vehicle speed on the side will be corrected appropriately.

  In step S34, it is determined whether or not the fixed time interval process has been completed. If it is determined that the fixed time interval process has not ended, the target travel route is divided into fixed minute time intervals in step S35. Then, an array of the coordinates of each point is created in a plurality of areas into which the target travel route is divided. Subsequently, in step S36, a plurality of arrays of a turning radius R and a time interval with respect to the time from the travel start point are created in a plurality of regions where the target travel route is divided.

  Then, similarly to the processing at Step S17 described above, the vehicle maximum speed V in each divided region is calculated by the equation of motion using the turning radius R of the road and the friction coefficient μ between the tire and the road surface. When it is determined that the maximum vehicle speed V in all the divided regions in the target travel route has been calculated, a steady circle maximum speed pattern is generated in step S19.

  Subsequently, in steps S20 to S26, the acceleration between adjacent points is calculated from the travel start point to the travel end point with respect to the steady circle maximum speed pattern in the generated target travel route. In steps S27 to S33, the deceleration between adjacent points is calculated from the travel end point to the travel start point with respect to the steady circle maximum speed pattern in the target travel route.

  Thereafter, in step S34, it is determined whether or not the fixed time interval process has been completed. If it is determined that the fixed time interval process has been completed, the process ends. In addition, you may repeat a fixed time interval process in multiple times as needed.

  As described above, the vehicle travel control apparatus according to the first embodiment is configured to generate the speed pattern along the target travel route and control the travel of the vehicle based on the speed pattern. A first speed state correcting means for executing a speed state correcting process from the control start position toward the travel control end position; and a speed state correction process from the travel control end position toward the travel control start position on the target travel route. Second speed state correcting means for executing correction processing is provided.

  Accordingly, the speed state is corrected from the start position to the end position of the travel control on the target travel route without using the optimization method, and the speed state is corrected from the end position of the travel control to the start position. By executing the processing, a speed pattern corresponding to the travel route is generated in a short time, and appropriate travel control of the vehicle can be performed based on the speed pattern.

  In the vehicle travel control apparatus of the first embodiment, the ECU 10 serving as the first speed state correcting unit and the second speed state correcting unit corrects the speed state on the acceleration side and corrects the speed state on the deceleration side. ing. In this case, the ECU 10 corrects the speed state to the low speed side. Therefore, the processing can be simplified by separately performing the correction processing for the speed state on the acceleration side and the correction processing for the speed state on the deceleration side and correcting the speed state on the low speed side.

  Further, in the vehicle travel control apparatus of the first embodiment, a travel route dividing unit that divides the target travel route at a constant interval is provided, and the ECU 10 corrects the speed state for each divided region, and speeds of adjacent regions The state is compared, and the speed state in the high speed region is corrected to the low speed side. In this case, the ECU 10 compares the accelerations or decelerations of adjacent areas and performs correction processing so as to suppress excessive acceleration or excessive deceleration. Therefore, the target travel route is divided at regular intervals, and the speed state is corrected to the low speed side for each region, so that the speed state can be corrected with high accuracy.

  In the first embodiment described above, the acceleration between adjacent points is calculated from the travel start point to the travel end point with respect to the steady circle maximum speed pattern in the target travel route, and then the travel start point from the travel end point. Although the deceleration between adjacent points was calculated toward the road, the deceleration between adjacent points was calculated from the end point of travel toward the start point of travel for the steady circle maximum speed pattern on the target travel route. The acceleration between adjacent points may be calculated from the start point toward the travel end point.

  FIG. 9 is a flowchart for generating a speed pattern corresponding to a travel route in the vehicle travel control apparatus according to the second embodiment of the present invention. The overall configuration of the vehicle travel control apparatus according to the present embodiment is substantially the same as that of the first embodiment described above, and will be described with reference to FIG. 1 and a member having the same function as that described in the present embodiment. Are denoted by the same reference numerals and redundant description is omitted.

  In the vehicle travel control apparatus according to the second embodiment, the first speed state correcting unit and the second speed state correcting unit calculate an addition vector of acceleration or deceleration and lateral acceleration in adjacent regions, The speed is corrected based on the friction circle in the region. Specifically, the first speed state correcting unit and the second speed state correcting unit correct the speed of the adjacent region to the low speed side so that the addition vector does not exceed the friction circle in each region.

  The vehicle travel control apparatus according to the second embodiment will be specifically described. The vehicle travel control apparatus according to the second embodiment has a process that is executed continuously after the speed pattern generation process according to the first embodiment described above. That is, in the speed pattern generation processing in the first embodiment, if the target travel route is a curved travel route in which the turning radius R changes gently, such as an expressway, for example, a speed pattern can be appropriately generated. it can. However, in this case, since the maximum speed changes slowly in the speed pattern, the acceleration and deceleration during traveling on the curve are large for a curved traveling route in which the turning radius R changes suddenly. Therefore, if the vectors of longitudinal acceleration and lateral acceleration are added, the friction circle may be broken. Therefore, in the vehicle travel control device of the second embodiment, when the sum of the acceleration or deceleration vector and the lateral acceleration vector exceeds the friction circle, the acceleration or deceleration is reduced so that the sum of the vectors falls within the friction circle. Let

  When the speed pattern on the target travel route is generated as in the first embodiment, first, acceleration (vector) and lateral acceleration (vector) between adjacent points are added from the travel start point to the travel end point. Here, when the friction circle breaks down, correction is made to the low speed side so that the addition vector of acceleration at a point close to the travel end point is within the friction circle.

  Further, the deceleration (vector) and the lateral acceleration (vector) between adjacent points are added from the travel end point toward the travel start point. Here, when the friction circle breaks down, it is corrected to the low speed side so that the addition vector of acceleration at a point close to the traveling start point is within the friction circle.

  Originally, it is best to avoid the failure of the friction circle by reducing either acceleration or lateral acceleration, depending on the detailed situation in which the vehicle travels. Processing may not be optimal. However, in this embodiment, attention is paid to the fact that, at the adjacent point where acceleration or deceleration is suppressed, the speed is reduced and the lateral vector is reduced. As a result, the acceleration or deceleration is reduced at the adjacent point. Since the speed can be reduced, a substantially optimal speed pattern is generated even for the target travel route in which the turning radius R changes suddenly despite the high-speed processing.

  Here, the generation process of the speed pattern according to the travel route in the vehicle travel control apparatus of the second embodiment will be described in detail with reference to the flowchart of FIG.

In the speed pattern generation process according to the travel route in the vehicle travel control apparatus of the second embodiment, when the speed pattern generation process of the first embodiment (the flowchart in FIG. 2) is completed, as shown in FIG. In S48, the maximum speed is corrected based on the addition vector of adjacent points from the travel start point to the travel end point with respect to the speed pattern in the target travel route. That is, at step S41, sets the one section forward areas in running end point side from the running start point, in step S42, the maximum velocity V of the maximum speed V _n and the front region of the area (driving start point +1) _The passing time dt _n is calculated from the distance L _n between the two points of _n−1 .
dt _n = L _n / ((V _n−1 + V _n ) / 2)
Then, to calculate the acceleration Ax _n at this time.
Ax _n = (V _n −V _n−1 ) / dt _n

At step S43, it determines whether the acceleration Ax _n is 0 or less. Here, if it is determined that the acceleration Ax _n is 0 or less, the process proceeds to step S47. On the other hand, if it is determined that the acceleration Ax _n is greater than 0, at step S44, it extracts the turning radius R at each point, to calculate the lateral acceleration Ay _n.
Ay _n = ((V _n−1 + V _n ) / 2) ² / R
Subsequently, the acceleration Ax _n and the lateral acceleration Ay _n are vector-added to calculate the absolute value | A | of the acceleration addition vector. Note that sqrt is a square root.
| A | = sqrt (Ax _n ² + Ay _n ² )

In step S45, it is determined whether or not the absolute value | A | of the acceleration addition vector is equal to or less than the upper limit maximum acceleration A _max (friction coefficient μ × gravity acceleration g) of the friction circle. Here, if it is determined that the absolute value | A | of the acceleration addition vector is equal to or less than the upper limit maximum acceleration A _{max of} the friction circle, it is estimated that the friction circle has not failed, and the process proceeds to step S47. On the other hand, if it is determined that the absolute value | A | of the acceleration addition vector is larger than the upper limit maximum acceleration A _{max of} the friction circle, it is estimated that the friction circle is broken. In step S46, the acceleration Ax _n and the maximum speed V are estimated. Modify _n .
Ax _n = sqrt (μ × g) ² −Ay _n ² )
_{V n = (V n-1} + Ax n × dt n)
That is, when the addition vector breaks the friction circle, it is corrected to the low speed side so that the speed at the high speed and the point close to the travel end point does not exceed the friction circle.

At step S47, the determining whether the corrective action of the maximum speed V _n is completed from runner-up of the travel start point to the front point of the running end point. Here, if it is determined that the correction processing of the maximum speed V _n in all the regions has not been completed, at step S48, the after setting a segment forward areas in running end point side from the treated area (point) The processes of steps S42 to S47 are repeated. Then, when at step S47, the correction processing maximum speed V _n to the previous point of the running end point from the runner-up of the travel start point is determined to be complete, the process proceeds to step S49.

In steps S49 to S56, the maximum speed is corrected based on the addition vector of adjacent points from the travel end point to the travel start point with respect to the steady circle maximum speed pattern in the target travel route. That is, at step S49, the set of one section retracted region running start point side from the running end point, in step S50, the maximum velocity V of the maximum speed V _n and the front area of this region (running end -1) _The passing time is calculated from the distance L _n between the two points of _{n + 1} .
dt _n = L _n / ((V _n + V _{n + 1} ) / 2)
Then, to calculate the deceleration Ax _n at this time.
Ax _n = (V _{n + 1} −V _n ) / dt _n

In step S51, it determines whether the deceleration Ax _n is 0 or more. Here, the deceleration Ax _n is if it is determined to be 0 or more, the process proceeds to step S55. On the other hand, if the deceleration Ax _n is determined to less than 0, at step S52, it extracts the turning radius R at each point, to calculate the lateral acceleration Ay _n.
Ay _n = ((V _n−1 + V _n ) / 2) ² / R
Subsequently, the deceleration Ax _n and the lateral acceleration Ay _n are vector-added to calculate the absolute value | A | of the deceleration addition vector.
| A | = sqrt (Ax _n ² + Ay _n ² )

In step S53, it is determined whether or not the absolute value | A | of the deceleration addition vector is equal to or less than the upper limit maximum deceleration A _max (friction coefficient μ × gravity acceleration g) of the friction circle. Here, if it is determined that the absolute value | A | of the deceleration addition vector is equal to or less than the upper limit maximum deceleration A _{max of} the friction circle, it is estimated that the friction circle has not failed, and the process proceeds to step S55. On the other hand, if it is determined that the absolute value | A | of the deceleration addition vector is larger than the upper limit maximum deceleration A _{max of} the friction circle, it is estimated that the friction circle is broken, and in step S54, the deceleration Ax _n is determined. to correct the maximum speed _{V n.}
Ax _n = sqrt (μ × g) ² −Ay _n ² )
_{V n = (V n-1} + Ax n × dt n)
That is, when the addition vector breaks the friction circle, the speed is corrected to the low speed side so that the speed at a point close to the traveling start point does not exceed the friction circle.

In step S55, it determines whether the corrective action of the maximum speed V _n is completed before the point of running end point to the runner-up running start point. Here, if it is determined that the correction processing of the maximum speed V _n in all sections has not been completed, at step S56, after setting the one section retracted segment As a starting point side from the treated zone (point) , Steps S50 to S55 are repeated. Then, when at step S55, correction processing maximum speed V _n from the previous point to the runner-up of the travel start point of the travel end point is determined to be complete, the process ends.

  As described above, in the vehicle travel control apparatus according to the second embodiment, the ECU 10 calculates the addition vector of the acceleration or deceleration of the adjacent area and the lateral acceleration, and based on the addition vector and the friction circle in each area. The speed is corrected. Specifically, the speed of the adjacent region is corrected to the low speed side so that the addition vector does not exceed the friction circle in each region.

  Therefore, safety can be improved by setting the maximum speed at which the friction circle does not fail even in a region where the turning radius of the target travel route is large.

  10-1 and 10-2 are flowcharts for generating a speed pattern according to the travel route in the vehicle travel control apparatus according to the third embodiment of the present invention, and FIG. 11 is a jerk correction in the travel course. FIG. 12A is an explanatory diagram illustrating jerk correction for a speed pattern, and FIG. 12B is an explanatory diagram illustrating jerk correction for a speed pattern. The overall configuration of the vehicle travel control apparatus according to the present embodiment is substantially the same as that of the first embodiment described above, and will be described with reference to FIG. 1 and a member having the same function as that described in the present embodiment. Are denoted by the same reference numerals and redundant description is omitted.

  In the vehicle travel control apparatus according to the third embodiment, the first speed state correcting unit and the second speed state correcting unit calculate the jerk (jerk acceleration) of the adjacent region, and the jerk and preset upper and lower limits. The speed is corrected by comparing the value (limit value).

  In this case, when the change in speed of the three adjacent regions has a concave shape (convex shape downward), the speed is high and the speed state of the region on the correction process progress direction side is corrected to the low speed side. Further, when the speed change in the three adjacent areas has a convex shape (convex shape upward), the speed is high and the speed state of the intermediate area is corrected to the low speed side.

  The vehicle travel control apparatus according to the third embodiment will be specifically described. The vehicle travel control apparatus according to the third embodiment has a process that is executed continuously after the speed pattern generation process according to the first or second embodiment. is doing. That is, in the speed pattern generation process in the first or second embodiment, the vehicle is considered as one mass point. Therefore, when performing full acceleration to full deceleration before the curve runway, the maximum acceleration is changed to the maximum deceleration. A speed pattern in which the target maximum speed changes instantaneously is generated. However, when such traveling control is executed while an actual vehicle is traveling, the vehicle pitches and the posture of the vehicle is disturbed.

  Therefore, in the vehicle travel control apparatus of the third embodiment, in order to take into account the maximum response speed and riding comfort of the vehicle, the jerk (jerk acceleration) is calculated, and the jerk upper limit value and the jerk lower limit value are set. The speed pattern is corrected so that is within the jerk upper limit value and the jerk lower limit value.

  When the speed pattern in the target travel route is generated as in the first embodiment, first, jerk (jerk acceleration) within three points adjacent from the travel start point to the travel end point is calculated. Here, when the jerk exceeds the jerk upper limit value, the speed of the point closest to the running end point among the three points is corrected to the lower speed side so that the jerk of the three points becomes smaller than the jerk upper limit value. To do. This process can efficiently correct a region in which the three-point velocity change forms a concave shape and the neighborhood acceleration is plus (+).

  Further, jerk (jerk acceleration) within three points adjacent to the travel start point from the travel end point is calculated. Here, when the jerk exceeds the jerk upper limit value, the speed of the point closest to the starting point of the three points is corrected to the low speed side so that the three jerk points are smaller than the jerk upper limit value. To do. This processing can efficiently correct a region where the near-point acceleration is minus (-) in a region where the three speed changes form a concave shape.

  Subsequently, the jerk (jerk acceleration) within three points adjacent from the travel start point to the travel end point is calculated again. Here, when the jerk is below the jerk lower limit value, the speed at the center point among the three points is corrected to the low speed side so as to be larger than the lower limit value obtained by jerking the three points. This processing can efficiently correct a region in which the three-point speed change has a convex shape and the neighborhood acceleration is plus (+).

  Further, jerk (jerk acceleration) within three points adjacent to the travel start point from the travel end point is calculated. Here, when the jerk is below the jerk lower limit value, the speed at the center point among the three points is corrected to the low speed side so that the jerk at the three points becomes larger than the jerk lower limit value. This processing can efficiently correct a region in which the three-point speed change has a convex shape and the near acceleration is minus (−).

  In the second scan from the travel start point to the travel end point and the scan from the travel end point to the travel start point, the speed at the center point of three adjacent points is corrected. Therefore, among the three points, the first point in the traveling direction, that is, the point on the travel start point side in the scan from the travel start point to the travel end point, and the travel end point side in the scan from the travel end point to the travel start point The point is not corrected. In this case, there is a possibility that the jerk lower limit value cannot be satisfied by one scan. Therefore, in order to speed up the convergence, it is preferable to add a margin α (for example, 10%) to the jerk lower limit value. As the margin α increases, an error occurs with respect to a more accurate value. Therefore, it is necessary to set the margin α appropriately depending on processing time and control accuracy. In addition, since there is a possibility that the upper limit acceleration used in the first embodiment may be exceeded by this correction processing, it is necessary to consider the upper limit acceleration used in the first embodiment even for the correction processing by the jerk of the present embodiment. There is.

  Here, the generation process of the speed pattern according to the travel route in the vehicle travel control apparatus of the third embodiment will be described in detail with reference to the flowcharts of FIGS. 10-1 and 10-2.

  In the speed pattern generation process according to the travel route in the vehicle travel control apparatus of the third embodiment, when the speed pattern generation process of the first embodiment (the flowchart of FIG. 2) is completed, as shown in FIG. In S61 to S69, the maximum speed is corrected based on the three adjacent jerks from the travel start point to the travel end point with respect to the speed pattern in the target travel route. This processing can efficiently correct a region where the near-point acceleration is minus (-) in a region where the three speed changes form a concave shape.

That is, at step S61, sets the one section forward areas in running end point side from the running start point, in step S62, the maximum velocity V of the maximum speed V _n and the front region of the area (driving start point +1) _The passage times dt ₁ and dt ₂ are calculated from the distances L ₁ and L ₂ between the points of _n−1 and the maximum speed V _{n + 1} of the previous region.
dt ₁ = L ₁ / ((V _n−1 + V _n ) / 2)
dt ₂ = L ₂ / ((V _n + V _{n + 1} ) / 2)
Subsequently, accelerations A ₁ and A ₂ at this time are calculated.
A ₁ = (V _n −V _n−1 ) / dt ₁
A ₂ = (V _{n + 1} −V _n ) / dt ₂
Furthermore, the jerk (jerk) J at this time is calculated.
J = (A ₂ −A ₁ ) / (dt ₁ + dt ₂ ) / 2)

In step S63, it is determined whether or not the jerk J is equal to or less than the upper limit jerk J _max1 (for example, 6 m / s ³ ). Here, if it is determined that the jerk J is _{equal to} or less than the upper limit jerk J _max1 , since the jerk limit condition is satisfied, the process _proceeds to step S65. On the other hand, the jerk J is if it is determined that the larger the upper limit jerk _{J max1,} at step S64, so as to satisfy the jerk limiting condition, correcting the acceleration _{A 2.}
A ₂ = A ₁ + J _max1 × ((dt ₁ + dt ₂ ) / 2)

At step S65, the acceleration A ₂ is (the maximum speed is set according to the vehicle performance - upper acceleration limit map) map determines it is not more than the upper acceleration A _max1 extracted from. Here, the acceleration _{A 2} is when it is judged whether it is not more than the upper acceleration _{A max1,} the process proceeds to step S67. On the other hand, the acceleration _{A 2} is if it is determined that the larger the upper limit acceleration _{A max1,} at step S66, the re-correct the upper limit acceleration _{A max1} the acceleration _{A 2.} Here, there are times when the acceleration set by the vehicle performance is not possible, in this case, the upper limit acceleration A _max1 corresponding to vehicle performance is prioritized than the acceleration A ₂ set from jerk.

In step S67, the maximum speed Vn _{+ 1} is corrected.
V _{n + 1} = V _n + A ₂ × dt ₂
That is, when there is an excess of jerk, the speed at a point that is high in speed and close to the travel end point is corrected to the low speed side.

In step S68, it determines whether the corrective action of the maximum speed V _n is completed from runner-up of the travel start point to two points before the running end point. Here, if it is determined that the correction processing of the maximum speed V _n in all the regions has not been completed, at step S69, after setting the one section forward areas in running end point side from the treated area (point) The processes in steps S62 to S68 are repeated. Then, in step S68, When the correction processing maximum speed V _n from runner-up of the travel start point to two points before the running end point is determined to be complete, the process proceeds to step S70.

Maximum speed of the the running start point maximum speed of the correction process using the jerk towards running end point in detail from that described, as shown in Figure 12-1, the points and their short of the maximum speed V _n points When V _n−1 and the maximum speed V _{n + 1} of the point ahead are set, the jerk J between these three points is calculated. If the jerk J is larger than the upper limit jerk J _max1 , the maximum speed V _{N + 1} is corrected. In this case, the speed is high and the point close to the travel end point, that is, the maximum speed V _{n + 1} is corrected to the low speed side.

  In steps S70 to S77, the maximum speed is corrected based on three adjacent jerks from the travel end point to the travel start point with respect to the speed pattern in the target travel route. This processing can efficiently correct a region where the near-point acceleration is minus (-) in a region where the three speed changes form a concave shape.

That is, the maximum speed of the maximum speed V _n and the front region of at step S70, the set of one section retracted region running start point side from the running end point, in step S71, the area (running end point -1) The passage times dt ₁ and dt ₂ are calculated from the distances L ₁ and L ₂ between the points of V _{n + 1} and the maximum velocity V _n−1 of the previous region.
dt ₁ = L ₁ / ((V _n−1 + V _n ) / 2)
dt ₂ = L ₂ / ((V _n + V _{n + 1} ) / 2)
Subsequently, accelerations A ₁ and A ₂ at this time are calculated.
A ₁ = (V _n −V _n−1 ) / dt ₁
A ₂ = (V _{n + 1} −V _n ) / dt ₂
Furthermore, the jerk (jerk) J at this time is calculated.
J = (A ₂ −A ₁ ) / (dt ₁ + dt ₂ ) / 2)

In step S72, it is determined whether the jerk J is _{equal to} or less than the upper limit jerk J _max1 . Here, if it is determined that the jerk J is _{equal to} or less than the upper limit jerk J _max1 , since the jerk limit condition is satisfied, the process _proceeds to step S74. On the other hand, the jerk J is if it is determined that the larger the upper limit jerk _{J max1,} at step S73, so as to satisfy the jerk limiting condition, modifies the acceleration _{A 1.}
A ₁ = A ₂ −J _max1 × ((dt ₁ + dt ₂ ) / 2)

At step S74, the determining whether the acceleration _{A 1} is equal to or smaller than the upper acceleration _{A max1.} Here, the acceleration _{A 1} is when it is judged whether it is not more than the upper acceleration _{A max1,} the process proceeds to step S76. On the other hand, the acceleration _{A 1} is if it is determined that the larger the upper limit acceleration _{A max1,} at step S75, the re-correct the upper limit acceleration _{A max1} the acceleration _{A 1.} Here, there is a case where the acceleration set according to the vehicle performance is impossible, and in this case, the upper limit acceleration A _max1 corresponding to the vehicle performance is prioritized over the acceleration A ₁ set from the jerk.

In step S76, the maximum speed Vn _-1 is corrected.
_{V n-1 = V n -A} 1 × dt 1
That is, when there is an excess of jerk, the speed at a point that is high in speed and close to the travel start point is corrected to the low speed side.

At step S77, the determining whether the corrective action of the maximum speed V _n is completed before the point of the running end point to the next two points of the travel start point. Here, if it is determined that the correction processing of the maximum speed V _n in all the regions has not been completed, at step S78, after setting the one section forward areas As a starting point side from the treated area (point) , Steps S70 to S77 are repeated. Then, when at step S77, the correction processing maximum speed V _n from the previous point to the next two points of the travel start point of the travel end point is determined to be complete, the process proceeds to step S79.

  As shown in FIG. 10-2, in steps S78 to S83, the maximum speed is corrected based on three adjacent jerks from the travel start point to the travel end point with respect to the speed pattern in the target travel route. This processing can efficiently correct a region in which the three-point speed change has a convex shape and the neighborhood acceleration is plus (+).

That is, at step S79, sets the one section forward areas in running end point side from the running start point, in step S80, the maximum velocity V of the maximum speed V _n and the front region of the area (driving start point +1) _The passage times dt ₁ and dt ₂ are calculated from the distances L ₁ and L ₂ between the points of _n−1 and the maximum speed V _{n + 1} of the previous region.
dt ₁ = L ₁ / ((V _n−1 + V _n ) / 2)
dt ₂ = L ₂ / ((V _n + V _{n + 1} ) / 2)
Subsequently, accelerations A ₁ and A ₂ at this time are calculated.
A ₁ = (V _n −V _n−1 ) / dt ₁
A ₂ = (V _{n + 1} −V _n ) / dt ₂
Furthermore, the jerk (jerk) J at this time is calculated.
J = (A ₂ −A ₁ ) / (dt ₁ + dt ₂ ) / 2)

In step S81, it is determined whether or not the jerk J is equal to or higher than the lower limit jerk J _max2 (for example, −6 m / s ³ ). Here, if it is determined that the jerk J is _{equal to} or greater than the lower limit jerk J _max2 , since the jerk limit condition is satisfied, the process proceeds to step S83. On the other hand, if it is determined that the jerk J is smaller than the lower limit jerk J _max2 , a jerk lower limit margin coefficient k (for example, 0.9) is set in step S82 in order to speed up the convergence. Then, the acceleration A ₁ and the maximum speed V _n are corrected so as to satisfy the jerk limit condition.
_{A 1 = (V n + 1} -V n-1) / (dt 1 + dt 2) + J max2 × dt 1/2 × k
_{V n = V n-1 +} A 1 × dt 1
That is, when there is an excess of jerk, the speed is high and the speed at the intermediate point is corrected to the low speed side.

At step S83, the determining whether the corrective action of the maximum speed V _n is completed from runner-up of the travel start point to two points before the running end point. Here, if it is determined that the correction processing of the maximum speed V _n in all the regions has not been completed, at step S84, the after setting a segment forward areas in running end point side from the treated area (point) The processes of steps S79 to S82 are repeated. Then, at step S83, the After correction processing maximum speed V _n from runner-up of the travel start point to two points before the running end point is determined to be complete, the process proceeds to step S85.

Maximum speed of the the running start point maximum speed of the correction process using the jerk towards running end point in detail from that described, as shown in Figure 12-2, the points and their short of the maximum speed V _n points When V _n−1 and the maximum speed V _{n + 1} of the point ahead are set, the jerk J between these three points is calculated. If the jerk J is larger than the upper limit jerk J _max2 , the maximum speed V _N is corrected. In this case, the speed is high and the intermediate point, that is, the speed of the maximum speed V _{n + 1} is corrected to the low speed side.

  In steps S85 to S89, the maximum speed is corrected based on three adjacent jerks from the travel end point to the travel start point with respect to the speed pattern on the target travel route. This processing can efficiently correct a region in which the three-point speed change has a convex shape and the neighborhood acceleration is plus (+).

That is, the maximum speed of the maximum speed V _n and the front region of at step S85, the set of one section retracted region running start point side from the running end point, in step S86, the area (running end point -1) The passage times dt ₁ and dt ₂ are calculated from the distances L ₁ and L ₂ between the points of V _{n + 1} and the maximum velocity V _n−1 of the previous region.
dt ₁ = L ₁ / ((V _n−1 + V _n ) / 2)
dt ₂ = L ₂ / ((V _n + V _{n + 1} ) / 2)
Subsequently, accelerations A ₁ and A ₂ at this time are calculated.
A ₁ = (V _n −V _n−1 ) / dt ₁
A ₂ = (V _{n + 1} −V _n ) / dt ₂
Furthermore, the jerk (jerk) J at this time is calculated.
J = (A ₂ −A ₁ ) / (dt ₁ + dt ₂ ) / 2)

In step S87, it is determined whether or not the jerk J is _{equal to} or greater than the lower limit jerk _Jmax2 . If it is determined that the jerk J is _{equal to} or greater than the lower limit jerk J _max2 , the process proceeds to step S89 because the jerk limit condition is satisfied. On the other hand, if it is determined that the jerk J is smaller than the lower limit jerk J _max2 , a jerk lower limit margin coefficient k (for example, 0.9) is set in step S88 in order to speed up the convergence. Then, the acceleration A ₂ and the maximum speed V _n are corrected so as to satisfy the jerk limit condition.
_{A 2 = (V n + 1} -V n-1) / (dt 1 + dt 2) + J max2 × dt 2/2 × k
V _n = V _{n + 1} + A ₂ × dt ₂
That is, when there is an excess of jerk, the speed is high and the speed at the intermediate point is corrected to the low speed side.

In step S89, it determines whether the corrective action of the maximum speed V _n is completed before the point of the running end point to the next two points of the travel start point. Here, if it is determined that the correction processing of the maximum speed V _n in all the regions has not been completed, at step S89, after setting the one section forward areas As a starting point side from the treated area (point) , Steps S86 to S89 are repeated. Then, when at step S88, correction processing maximum speed V _n from the previous point to the next two points of the travel start point of the travel end point is determined to be complete, the process ends.

Relative speed pattern, by conducting correction processing maximum speed V _n with jerk between the travel start point and the travel end point, as in the bold line shown in FIG. 11, in each curve track, each divided section Thus, the vehicle speed at the point where the deceleration is changed from the deceleration to the acceleration is appropriately corrected.

  As described above, in the vehicle travel control apparatus according to the third embodiment, the ECU 10 calculates the jerk (jerk acceleration) of the adjacent region, and uses this jerk and preset limit values (upper limit value and lower limit value). The speed is corrected and compared.

  Therefore, it is possible to generate a stable speed pattern without disturbing the posture with respect to the pitching of the vehicle, and to improve the riding comfort of the vehicle.

  Further, in the vehicle travel control device of the third embodiment, when the speed change in the adjacent area has a concave shape, the speed is high, and the speed state of the area on the correction processing progress direction side is corrected to the low speed side, while adjacent. When the speed change of the area has a convex shape, the speed is high and the speed state of the intermediate area is corrected to the low speed side. Therefore, the speed correction can be optimally performed according to the speed change of the adjacent area.

  FIG. 13 is a flowchart for generating a speed pattern according to the travel route in the vehicle travel control apparatus according to the fourth embodiment of the present invention. The overall configuration of the vehicle travel control apparatus according to the present embodiment is substantially the same as that of the first embodiment described above, and will be described with reference to FIG. 1 and a member having the same function as that described in the present embodiment. Are denoted by the same reference numerals and redundant description is omitted.

  In the vehicle travel control apparatus according to the fourth embodiment, the first speed state correcting unit and the second speed state correcting unit compare the jerk with the preset upper limit value and lower limit value (limit value) to correct the speed. However, the upper limit value and the lower limit value are set according to the shape of the target travel route.

  The vehicle travel control apparatus according to the fourth embodiment will be specifically described. The vehicle travel control apparatus according to the fourth embodiment includes a process that is executed during the speed pattern generation process according to the third embodiment described above. That is, in the speed pattern generation process in the third embodiment, the speed pattern is corrected using the jerk limit value in order to prevent the posture of the vehicle from being disturbed due to the pitching of the vehicle. When the curve changes from a straight line to a curve, a large change in the turning radius R results in a speed pattern in which steering is performed by returning the deceleration to 0 from full braking. This speed pattern is an optimal solution in the range where the vehicle is regarded as one mass point, but in actual vehicles, the load on the front wheels for generating the yaw rate of the vehicle is lost, making the vehicle faster and safer. Driving may result in an inappropriate speed pattern.

Therefore, in the vehicle travel control device of the fourth embodiment, when the travel line is displaced from a straight line to a curve, the acceleration is large and negative (for example, −0.2 G or less) and the jerk is positive, that is, while the brake is weakened. In the state where cornering is started, the limit value of the jerk is set to a small value (for example, 3 m / s ³ ), thereby preventing load loss of the front wheels. During the speed pattern generation process in the above-described third embodiment, it is possible to divert only by changing the jerk limit value. The deceleration start point is adjusted so that the speed adjustment is optimized within the range without entering. A vehicle traveling from a straight line to a curve requires a force that starts turning in the yaw direction due to the load on the front wheel as the curve has a large yaw rate change. Set low.

  Here, the generation process of the speed pattern according to the travel route in the vehicle travel control apparatus of the fourth embodiment will be described in detail with reference to the flowchart of FIG.

  The speed pattern generation process according to the travel route in the vehicle travel control apparatus according to the fourth embodiment is executed during the speed pattern generation process according to the third embodiment (the flowcharts of FIGS. 10-1 and 10-2). That is, as shown in FIG. 13, in step S101, the region of the travel start point is set, and in step S102, it is determined whether or not the acceleration of the vehicle is smaller than -0.2G. Here, if it is determined that the acceleration of the vehicle is −0.2 G or more, the process proceeds to step S109.

On the other hand, it is determined at step S102, When the acceleration of the vehicle is determined to -0.2G smaller, at step S103, whether the jerk is greater than 1 m / ^{s 3.} In this case, it is determined whether or not the jerk is positive, but it is compared with 1 m / s ³ in consideration of an error or the like. Here, if it is determined that the jerk is 1 m / s ³ or less, the process proceeds to step S109. On the other hand, if it is determined in step S103 that the jerk is greater than 1 m / s ^3, it is determined in step S104 whether the vehicle is traveling on a curve, that is, whether the turning radius R of the vehicle is greater than 300 m. judge. Here, if it is determined that the turning radius R of the vehicle is 300 m or less, the process proceeds to step S109.

On the other hand, if it is determined that the turning radius R of the vehicle is larger than 300 m, the upper limit jerk J _max1 is set _smaller in step S105. In this case, in the third embodiment described above has been set as the upper limit jerk _J max1 = 6m / ^{s 3,} in the fourth embodiment, is set to the upper limit jerk _J max1 = 3m / ^{s 3.} In step S106, the yaw rate γ ₁ is calculated from the relationship between the speed of the point in the region to be processed and the turning radius R, the yaw rate γ _{2 of the} adjacent point is calculated, and the yaw rate differential value is calculated from the amount of change.
Yaw rate differential value = (γ ₂ −γ ₁ ) dt

Then, in step S107, it is determined whether or not the yaw rate differential value is larger than a preset set value. If it is larger, in step S108, the upper limit jerk J _max1 is further reduced, for example, the upper limit jerk J _max1 = 2 m / It is set to s ^3.

  In step S109, it is determined whether the upper limit jerk correction process has been completed from the travel start point to the travel end point. If it is determined that the correction process has not been completed, the processes in steps S102 to S109 are repeated to perform the correction process for the next area. If it is determined in step S109 that the upper limit jerk correction process has been completed from the travel start point to the travel end point, the process ends.

  Thus, in the vehicle travel control device of the fourth embodiment, the ECU 10 corrects the speed by comparing the jerk with the preset upper limit value and lower limit value. It is set according to the shape of the target travel route.

  Therefore, when the vehicle enters a curved road, it is possible to secure a front wheel load to enable proper yaw turning, and to generate a speed pattern with high safety and comfortable ride.

  FIG. 14 is a flowchart for generating a speed pattern according to the travel route in the vehicle travel control apparatus according to the fifth embodiment of the present invention. The overall configuration of the vehicle travel control apparatus according to the present embodiment is substantially the same as that of the first embodiment described above, and will be described with reference to FIG. 1 and a member having the same function as that described in the present embodiment. Are denoted by the same reference numerals and redundant description is omitted.

  In the vehicle travel control apparatus according to the fifth embodiment, the first speed state correcting unit and the second speed state correcting unit correct the speed state using the vehicle as a mass model, but the speed state of each divided area is changed. After the correction process is completed, the lateral force state is corrected using the vehicle as a rigid model.

  The vehicle travel control apparatus according to the fifth embodiment will be described in detail. The vehicle travel control apparatus according to the fifth embodiment includes a process executed during the speed pattern generation process according to the first embodiment. That is, in the speed pattern generation process in the first embodiment, since the vehicle is regarded as one mass point, in a situation where the yaw rate frequently changes when the vehicle travels in slalom, the vehicle yaw rate is overcome. There is a possibility that a lateral force for rotating in the yaw direction cannot be generated and the tire slips. In the third and fourth embodiments described above, there is an effect of stabilizing the posture of the vehicle by correcting the speed using the jerk, but essentially, forcibly rotating the vehicle that has entered the curve at an overspeed is impossible. It is physically hard and soft, and it is necessary to properly reduce the speed of the vehicle.

  Therefore, in the vehicle travel control apparatus of the fifth embodiment, not only the vehicle is regarded as one mass point, but also the vehicle is treated as a rigid body having a yaw rate moment of inertia and decelerated. In other words, when the vehicle turns from a straight road to a curved road, the burden on the front wheels increases in order to increase the yaw rate. Even if this increased burden is added to the yaw rate, the speed is reduced so that it falls within the friction circle of the tire. Specifically, when the absolute value of the yaw rate increases and the degree of yaw rate change (yaw rate differential value) is greater than the set value, the lateral force required to rotate the vehicle with only the front wheels is the lateral force required for the entire vehicle. In addition to (moment of inertia of yaw rate × yaw rate differential value / distance from center of gravity position of vehicle to Freon and axle), the speed of the vehicle is reduced. On the other hand, when the absolute value of the yaw rate decreases and the degree of change in yaw rate (yaw rate differential value) is larger than the set value, the front wheel only has to have a lower lateral force than the rear wheel, so this processing is not performed.

  Here, the generation process of the speed pattern according to the travel route in the vehicle travel control apparatus of the fifth embodiment will be described in detail with reference to the flowchart of FIG.

The speed pattern generation process corresponding to the travel route in the vehicle travel control apparatus according to the fifth embodiment is executed during the speed pattern generation process according to the first embodiment (the flowchart of FIG. 2). That is, as shown in FIG. 14, in step S111, the region of the travel start point is set, and in step S112, yaw rate γ ₁ is calculated from the relationship between the speed of the point in the region to be processed and the turning radius R, and The yaw rate γ _{2 of the} adjacent point is calculated. Then, in step S113, it determines whether the absolute value of the yaw rate gamma ₁ is smaller than the absolute value of the yaw rate gamma _2.

Here, if it is determined that the absolute value of yaw rate γ ₁ is greater than or equal to the absolute value of yaw rate γ ₂ , the process proceeds to step S117. On the other hand, if it is determined that the absolute value of yaw rate γ ₁ is smaller than the absolute value of yaw rate γ ₂ , the yaw rate differential value is calculated from the amount of change in yaw rates γ ₁ and γ ₂ in step S114.
Yaw rate differential value = (γ ₂ −γ ₁ ) dt

In step S115, it is determined whether the yaw rate differential value is larger than a preset value (for example, 10 deg / s ² ). Here, if it is determined that the yaw rate differential value is equal to or less than the set value, the process proceeds to step S117. On the other hand, if it is determined that the yaw rate differential value is larger than the set value, at step S116, it calculates a lateral force Ay ₂ necessary for generating the yaw rate differential value of the vehicle. Here, I is the moment of inertia of the yaw rate, and Lf is the distance from the vehicle center of gravity position to the Freon and the axle.
Ay ₂ = I × γ / Lf

Further, the lateral force Ay ₁ is calculated using the road friction coefficient μ and the gravitational acceleration g.
Ay ₁ = μ × g
Then, the friction coefficient μ of the road is considered in consideration of the inertia moment of the yaw rate and is changed to the friction coefficient μ.
Considered friction coefficient μ = μ × Ay ₁ / (Ay ₁ + Ay ₂ )

  In step S117, it is determined from the travel start point to the travel end point whether the correction process for the friction coefficient μ has been completed. If it is determined that the correction process has not been completed, the processes in steps S112 to S117 are repeated in order to correct the next area. If it is determined in step S117 that the correction process for the friction coefficient μ has been completed considering the travel start point to the travel end point, the process ends.

  As described above, in the vehicle travel control apparatus according to the fifth embodiment, when the ECU 10 performs the speed state correction process for each of the divided areas, the vehicle is used after the speed state correction process is completed using the vehicle as a mass point model. Is used to correct the lateral force state.

  Accordingly, it is possible to generate an appropriate speed pattern in which the vehicle travels while rotating in a traveling state in which the yaw rate frequently changes such that the vehicle travels in slalom.

  In the above-described embodiment, the vehicle travel control device according to the present invention has been described as applied to the automatic travel control of the vehicle. However, the present invention may be applied to an apparatus capable of automatic travel control and manual travel control.

  As described above, the vehicle travel control device according to the present invention corrects the speed state from the start position of the travel control to the end position on the target travel route, and also speeds from the end position of the travel control to the start position. By correcting the state, a speed pattern corresponding to the travel route is generated in a short time, and the travel of the vehicle can be controlled based on this speed pattern, which is useful when applied to any vehicle. is there.

10 Electronic control unit, ECU (pattern generating means, first speed state correcting means, second speed state correcting means)
DESCRIPTION OF SYMBOLS 11 Brake pedal sensor 12 Accelerator pedal sensor 13 Steering angle sensor 14 G (acceleration) sensor 15 Yaw rate sensor 16 Wheel speed sensor 17 White line recognition sensor 18 Navigation system 21 Throttle actuator 22 Brake actuator 23 Steering actuator

Claims (12)

In a vehicle travel control device that generates a speed pattern along a target travel route and controls the travel of the vehicle based on the speed pattern.
First speed state correction means for executing a speed state correction process from the start position of the travel control in the target travel path toward the end position of the travel control;
Second speed state correcting means for executing speed state correction processing from the end position of the travel control in the target travel path toward the start position of the travel control;
Provided ,
The first speed state correcting means corrects the speed state on the acceleration side to the low speed side, and the second speed state correcting means corrects the speed state on the deceleration side to the low speed side. Control device. A travel route dividing unit that divides the target travel route at regular intervals is provided, and the first speed state correcting unit and the second speed state correcting unit correct the speed state for each of the divided areas, and perform the division. 2. The vehicle travel control device according to claim 1 , wherein the speed states of the adjacent regions are compared, and the speed state of the region having the highest speed is corrected to the low speed side. A travel route dividing unit that divides the target travel route at regular intervals is provided, and the first speed state correcting unit and the second speed state correcting unit correct the speed state for each of the divided areas, and perform the division. The vehicle travel control device according to claim 1 , wherein the acceleration or deceleration for each adjacent area is compared, and the highest acceleration or deceleration is corrected to the lower side . 4. The vehicle travel control according to claim 3 , wherein the first speed state correcting unit and the second speed state correcting unit perform a correction process so that an acceleration or a deceleration of an adjacent region becomes an upper limit value or less. apparatus. The first speed state correcting unit and the second speed state correcting unit calculate an addition vector of acceleration or deceleration and lateral acceleration of adjacent regions, and based on the addition vector and the friction circle in each region The vehicle travel control device according to any one of claims 2 to 4 , wherein the vehicle is corrected. The first speed state altering means and the second speed state correcting means, so add vector does not exceed the friction circle in each region, claims, characterized in that the correction process the speed of the adjacent regions to the low speed side 5. The vehicle travel control device according to 5. The first speed state correcting unit and the second speed state correcting unit calculate jerk of an adjacent region, compare the jerk with a preset limit value, and reduce the speed so as to be smaller than the limit value. The vehicle travel control device according to any one of claims 2 to 4 , wherein the vehicle is corrected. Speed of the first speed state altering means and the second speed state correcting means, wherein when the speed change of the adjacent regions are represented in graph form a concave shape, the speed is high and correction process traveling direction side region The vehicle travel control device according to claim 7 , wherein the state is corrected to a low speed side. The first speed state altering means and the second speed state correcting means, an intermediate region of said when the speed change of the adjacent regions are represented in graph form a convex shape, the speed is high and the adjacent regions The vehicle travel control apparatus according to claim 7 , wherein the speed state is corrected to a low speed side. The vehicle travel control apparatus according to claim 7 , wherein the limit value is set according to a shape of a target travel route. 11. The vehicle travel control device according to claim 1, wherein the first speed state correcting unit and the second speed state correcting unit correct the speed state using the vehicle as a mass model. . The first speed state correcting unit and the second speed state correcting unit correct the lateral force state using the vehicle as a rigid model after completing the speed state correcting process for each divided area. The vehicle travel control device according to claim 11 .

Images