JP2010241351A - Vehicle controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle controller setting a restraint condition such that a travel plan to largely run over a road is not generated according to a convergence decision reference value even when too enlarging the convergence decision reference value of the restraint condition when online calculating the travel plan by use of optimization calculation so as to achieve vehicle travel control wherein both a calculation time and safety are simultaneously materialized. <P>SOLUTION: This vehicle controller variably sets the restraint condition according to the convergence decision reference value of an evaluation function used for the travel control of a vehicle. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a vehicle control device.

  Conventionally, in order to pass through a corner in the shortest time, a method has been developed in which an ideal trajectory is calculated using an optimization method by setting the passing time as an evaluation function.

  For example, in Non-Patent Document 1, by applying SCGRA (Sequential Conjugate Gradient-Restoration Algorithm), which is used for calculating optimal trajectories of artificial satellites and shuttles, to the motion calculation of a vehicle, the motion properties and driving control of the vehicle. Considering the method, the vehicle that can control both front and rear wheels independently calculates the optimal trajectory when passing the hairpin curve in the shortest time using the optimization method, and the motion characteristics when the parameter is changed Discussing changes.

Takehiko Fujioka, Daisho Emori, “Theoretical Study on Optimal Time Cornering Method-4th Report: Introduction of Road Conditions Using State Quantity Inequality Constraints”, Automobile Engineering Society Proceedings, Vol. 24, no. 3, July 1993, p. 106-111.

  However, in the optimal trajectory generation method using the conventional optimization method described in Non-Patent Document 1, it is not described how to set convergence determination reference values such as equations of motion, constraint conditions, and boundary conditions. When calculating an automobile travel plan using an optimization method, it is essential to devise a method for setting the size of the convergence criterion value so that the vehicle travels on the road. That is, in the conventional optimization method described in Non-Patent Document 1, when the predetermined function falls below a certain threshold value, the evaluation function becomes sufficiently small and is judged to have converged, and the calculation is terminated. There is a problem that it is necessary to consider vehicle stability on the road for setting the value. Further, in the optimum trajectory generation method using the conventional optimization method described in Non-Patent Document 1, it is determined that the evaluation function has converged under the convergence condition arbitrarily set in the simulation assuming the racing course. However, when applied to a general road as in the present invention, there has been a problem that a device that takes safety into consideration is necessary.

  The present invention has been made in view of the above problems, and in order to realize vehicle travel control that achieves both computation time and safety, when calculating a travel plan online using optimization computation, Even when the convergence criterion value that is a threshold value for the convergence condition is excessively increased, a vehicle control device that can set a constraint condition in consideration of safety on a general road according to the convergence criterion value The purpose is to provide.

  In order to achieve such an object, a vehicle control device of the present invention is a vehicle control device that includes at least a control unit that performs vehicle travel control using an evaluation function, and the control unit includes the evaluation function. And a constraint condition setting means for variably setting a constraint condition in accordance with the convergence determination reference value.

  In the vehicle control device according to the present invention, the constraint condition is a road condition related to road information.

  The vehicle control device according to the present invention is characterized in that, in the vehicle control device described above, the road condition is a road part condition relating to a road part in which vehicle travel is allowed.

  The vehicle control device according to the present invention is characterized in that, in the vehicle control device described above, the road partial condition is a condition related to a road width.

  Further, the vehicle control device according to the present invention is characterized in that, in the vehicle control device described above, the constraint condition setting means sets the limited constraint condition as the convergence determination reference value increases.

  In the vehicle control device according to the present invention, in the vehicle control device described above, the constraint condition setting unit is configured so that the road width allowed for the vehicle travel is narrowed as the convergence determination reference value increases. A constraint condition is set.

  In the vehicle control device according to the present invention, in the vehicle control device described above, the constraint condition setting means is the road width allowed for the vehicle travel as the constraint condition and an allowable error of the road width. The constraint condition is set so that the value obtained by adding the error margin becomes narrower than the actual road width, and the width of the error margin becomes wider as the convergence criterion value increases. To do.

  According to the present invention, the constraint condition can be variably set according to the convergence determination reference value of the evaluation function used for vehicle travel control. As a result, the present invention sets the constraint condition so that the calculation is completed during the actual running of the vehicle, and at the same time ensures the safety on the general road, even when the convergence criterion value of the optimization calculation is large It is possible to generate a traveling trajectory.

  Further, according to the present invention, the constraint condition can be a road condition related to road information. Thereby, this invention has an effect that the movement of a vehicle can be controlled based on road information.

  Further, according to the present invention, the road condition can be a road part condition related to a road part in which vehicle travel is allowed. Thereby, this invention has an effect that it can control so that the motion of a vehicle may be settled in a road.

  According to the present invention, the road partial condition can be a condition related to the road width. As a result, the present invention has an effect that it is possible to control the movement of the vehicle within a certain width within the road (for example, within a lane).

  Further, according to the present invention, the limited constraint condition can be set as the convergence criterion value increases. Thus, the present invention has an effect that the calculation time of the optimization calculation can be shortened by setting the degree of freedom of the constraint condition to be small.

  Further, according to the present invention, the constraint condition can be set such that the greater the convergence determination reference value, the narrower the road width allowed for vehicle travel. As a result, the present invention has an effect that it is possible to control the movement of the vehicle within the road width without requiring an enormous calculation time.

  Further, according to the present invention, a value obtained by adding the road width allowed for vehicle travel as a constraint condition and an error margin that is an allowable error of the road width is set to be narrower than the actual road width. The constraint condition can be set so that the error margin becomes wider as the convergence criterion value increases. As a result, the present invention makes it possible to match the equation of motion by taking a margin as an allowable error from the actual road width, by taking an error generated by easily increasing the convergence determination reference value used for the convergence determination on the set condition side. It is possible to avoid an increase in the error of determination such as the nature of the vehicle and the movement of the vehicle within the road. Thereby, this invention has the effect of implement | achieving vehicle driving | running | working which considered safety by putting the motion of a vehicle in a road.

FIG. 1 is a block diagram showing an example of the configuration of this system. FIG. 2 is a flowchart showing an example of optimization calculation processing performed by the present system. FIG. 3 is a schematic diagram showing an example of the road width used in the error margin and the constraint condition calculated in the present embodiment.

  Hereinafter, embodiments of a vehicle control device according to the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

[1. Constitution]
First, a configuration of a system according to the present embodiment (hereinafter may be referred to as the present system) including an electronic control device for carrying out the traveling locus generating method according to the present invention and a vehicle control device according to the present invention. Will be described with reference to FIG. FIG. 1 is a block diagram showing an example of the configuration of this system.

  This system calculates the travel trajectory of a vehicle when traveling on a road based on an optimization method using travel time, vehicle stability, fuel consumption, etc. as an index, and controls the motion of the vehicle based on the calculated travel trajectory. System. It should be noted that the “travel locus” in the present embodiment is a concept that includes both the line through which the vehicle passes and the speed on the line through which the vehicle passes. As shown in FIG. 1, this system is schematically configured by a vehicle ECU 100.

  The vehicle ECU 100 is an electronic control device, and generally includes a control unit 102 and a storage unit 106. The control unit 102 and the storage unit 106 are communicably connected via an arbitrary communication path.

  The storage unit 106 is a storage unit. For example, a memory device such as a RAM / ROM, a fixed disk device such as a hard disk, a flexible disk, an optical disk, or the like can be used. The storage unit 106 stores a computer program for giving instructions to the CPU and performing various processes in cooperation with an OS (Operating System). The storage unit 106 generally includes a road information file 106a.

  The road information file 106a is road information storage means for storing road information. The road information file 106a includes roads related to road shapes (straight lines, curves, widths, etc.), road segment distances (section lengths), road boundaries (lanes, etc.), etc. I remember information.

  The control unit 102 is a CPU or the like that comprehensively controls the entire vehicle ECU 100. The control unit 102 has an internal memory for storing control programs such as an OS (Operating System), programs that define various processing procedures, and necessary data, and performs various information processing based on these programs. Execute. The control unit 102 includes a convergence determination criterion setting unit 102a, an error margin calculation unit 102b, a constraint condition setting unit 102c, an optimization calculation processing unit 102d, a convergence determination unit 102e, and a vehicle travel control unit 102f in terms of functional concept.

  The convergence criterion setting unit 102a is a convergence criterion setting unit that sets the convergence criterion value ε1 of the evaluation function of the optimization calculation according to the calculation target (calculation time priority, accuracy priority, etc.). Here, the evaluation function may be set in advance, or may be set by the control unit 102 according to the optimum purpose in the vehicle travel control in the optimization calculation. Further, the optimum purpose may be, for example, a traveling with the shortest transit time, a traveling with the least vibration of the vehicle, a traveling with the best fuel consumption, or the like. Further, the convergence determination reference value ε1 may be a value indicating how small the error of the vehicle state quantity, the constraint condition, and the boundary condition is.

  The error margin calculation unit 102b is an error margin calculation unit that calculates an error margin that is an allowable error of the road width allowed for vehicle travel according to the convergence determination reference value ε1 set by the convergence determination reference setting unit 102a. .

  The constraint condition setting unit 102c is a constraint condition setting unit that variably sets a constraint condition according to the convergence criterion value ε1 of the evaluation function. That is, the constraint condition setting unit 102c is a constraint condition setting unit that sets a constraint condition for optimization calculation based on the error margin calculated by the error margin calculation unit 102b in accordance with the convergence determination reference value ε1. Here, the constraint condition may be a road condition related to road information. Further, the road condition may be a road part condition regarding a road part in which vehicle travel is allowed. Further, the road partial condition may be a condition related to a road width. Further, the constraint condition setting unit 102c may set a limited constraint condition as the convergence determination reference value ε1 increases. In addition, the constraint condition setting unit 102c may set the constraint condition such that the greater the convergence determination reference value ε1, the narrower the road width allowed for vehicle travel. In addition, the constraint condition setting unit 102c is a value obtained by adding the allowable road width of the vehicle as the constraint condition and the error margin that is the allowable error of the road width calculated by the error margin calculation unit 102b. It may be set so as to be narrower than the road width, and the constraint condition may be set by causing the error margin calculation unit 102b to calculate so that the width of the error margin becomes wider as the convergence determination reference value ε1 increases.

  The optimization calculation processing unit 102d is an optimization calculation processing unit that calculates a travel locus using an optimization method based on the evaluation function and the constraint condition set by the constraint condition setting unit 102c. Specifically, the optimization calculation processing unit 102d determines the shape of the road section (straight line, curve, width, etc.), the section distance of the road section (section length), and the road to be calculated based on the optimization method. An initial solution is obtained based on a vehicle equation of motion, constraint conditions, initial conditions, termination conditions, control formulas, etc. set by acquiring road information about boundaries (lanes, etc.) from the road information file 106a, and conjugate with the evaluation function. An optimal solution may be calculated by performing a convergence calculation based on an optimization method such as a gradient method. The evaluation function may be calculated by a steepest descent method, a Newton method, a quasi-Newton method, or the like.

  The convergence determination unit 102e determines whether or not the value of the travel locus calculated by the optimization calculation processing unit 102d satisfies the convergence determination reference value ε1 of the evaluation function set by the convergence determination reference setting unit 102a. Means.

  The vehicle travel control unit 102f controls the travel of the vehicle based on the travel locus calculated by the optimization calculation processing unit 102d, which is determined to satisfy the convergence determination reference value ε1 by the convergence determination unit 102e.

[2. processing]
Next, an example of the optimization calculation process performed by the system configured as described above will be described in detail with reference to FIGS.

  Details of the optimization calculation processing in this system will be described with reference to FIG. FIG. 2 is a flowchart showing an example of optimization calculation processing performed by the present system. FIG. 3 is a schematic diagram showing an example of the road width used in the error margin and the constraint condition calculated in the present embodiment.

  As shown in FIG. 2, first, the convergence criterion setting unit 102a sets the convergence criterion value ε1 of the evaluation function of the optimization calculation according to the calculation target (calculation time priority, accuracy priority, etc.) (step SA). -1).

  Then, the error margin calculation unit 102b calculates an error margin that is an allowable error of the road width allowed for vehicle travel according to the convergence determination reference value ε1 set by the convergence determination reference setting unit 102a (step SA−). 2).

Here, as an example, calculation of an error margin by this system will be described. In this system, since the convergence determination reference value ε1 includes a value P2 indicating how much the road protrudes due to vehicle motion, it is assumed that P2 = ε1 and an error margin is set in advance (ie, , Put the protruding part within the actual road width). Specifically, in this system, P2 that is dimensionless in a form suitable for the optimization calculation can be expressed as follows.
P2 = (Extruding amount / Road width) ^ 2 × Kp2
(Here, Kp2 is a variable depending on the dimensionless amount, the setting conditions, and the integral calculation method)
For example, the calculated value P_2 of P2 when (the amount of protrusion / road width) is 0.005 is 10 ^ (− 15), and is divided by the convergence criterion setting unit 102a within the calculation possible time during vehicle travel. When the issued convergence determination reference value ε1 is 10 ^ (-11), since the value P2 is included in the convergence determination reference value ε1, assuming that P_2 = ε1, 10 ^ 4 × P_2 = The equation for ε1 holds. Accordingly, when applied when the vehicle is running, (the amount of protrusion / road width) is calculated as 0.5 (that is, (the amount of protrusion / road width) = sqrt (10 ^ 4) × 0.005). That is, in the present embodiment, the width of the error margin is a road portion having a width of 50% with respect to the road width used in the constraint condition.

  Then, the constraint condition setting unit 102c is based on the error margin calculated by the error margin calculation unit 102b in accordance with the convergence determination reference value ε1 of the evaluation function (that is, (extraction amount / road width) = 0.5). Then, a constraint condition for optimization calculation is variably set (that is, a road width that is 1 / (1 + 0.5) times the actual road width is set as the road width used in the constraint condition) (step SA-3). Here, the constraint condition may be a road condition related to road information. Further, the road condition may be a road part condition regarding a road part in which vehicle travel is allowed. Further, the road partial condition may be a condition related to a road width. Further, the constraint condition setting unit 102c may set a limited constraint condition as the convergence determination reference value ε1 increases. In addition, the constraint condition setting unit 102c may set the constraint condition such that the greater the convergence determination reference value ε1, the narrower the road width allowed for vehicle travel. In addition, the constraint condition setting unit 102c is a value obtained by adding the allowable road width of the vehicle as the constraint condition and the error margin that is the allowable error of the road width calculated by the error margin calculation unit 102b. It may be set so as to be narrower than the road width, and the constraint condition may be set by causing the error margin calculation unit 102b to calculate so that the width of the error margin becomes wider as the convergence determination reference value ε1 increases.

  Here, with reference to FIG. 3, an example of the road width used in the error margin and the constraint condition calculated in the present embodiment will be described.

  As shown in FIG. 3, in the present embodiment, as an example, the error margin calculation unit 102b has a width of 50% of the road width used in the constraint condition, that is, about 16.67 on both sides of the road. % Error margin (shaded portion) is calculated, and the road width of the portion obtained by subtracting the error margin (shaded portion) from the actual road width, that is, about 66.7% of the actual road width (that is, the actual road) The central portion of the road width 1 / (1 + 0.5) times the width is used as the road width used in the constraint condition.

  Next, returning to FIG. 2 again, the optimization calculation processing unit 102d calculates a travel locus using an optimization method based on the evaluation function and the constraint condition set by the constraint condition setting unit 102c (step SA). -4).

  When the convergence determination unit 102e determines that the value of the travel locus calculated by the optimization calculation processing unit 102d does not satisfy the convergence determination reference value ε1 of the evaluation function set by the convergence determination reference setting unit 102a ( Step SA-5: No), the process returns to Step SA-4.

  On the other hand, when the convergence determination unit 102e determines that the value of the travel locus calculated by the optimization calculation processing unit 102d satisfies the convergence determination reference value ε1 of the evaluation function set by the convergence determination reference setting unit 102a (step SA-5: Yes), and the optimization calculation process is terminated.

[3. Summary of this embodiment and other embodiments]
According to the present embodiment, the convergence determination reference value ε1 of the optimization function evaluation function is set according to the calculation target, and the road width allowed for vehicle travel according to the set convergence determination reference value ε1. An error margin, which is an allowable error, is calculated, and a constraint condition for optimization calculation is variably set based on the calculated error margin according to the convergence criterion value ε1 of the evaluation function, and is set as an evaluation function. When the travel locus is calculated using an optimization method based on the constraint conditions and the calculated travel locus value is determined not to satisfy the convergence criterion value ε1 of the set evaluation function, the travel locus is again calculated. On the other hand, if it is determined that the calculated value of the travel locus satisfies the convergence criterion value ε1 of the set evaluation function, the optimization calculation process is terminated. As a result, a calculation result that does not protrude from the road if the error margin with respect to the road width is taken from the set convergence determination reference value ε1 without requiring enormous time (ie, , A travel locus) can be obtained.

  Finally, the vehicle control apparatus according to the present invention may be implemented in various different embodiments within the scope of the technical idea described in the claims, in addition to the above-described embodiments. . For example, among the processes described in the embodiments, all or part of the processes described as being automatically performed can be manually performed, or the processes described as being performed manually can be performed. All or a part can be automatically performed by a known method. Further, the processing procedure, control procedure, specific name, information including registration data and parameters of each processing shown in this specification and the drawings can be arbitrarily changed unless otherwise specified. In addition, regarding the vehicle ECU 100, the illustrated components are functionally conceptual and need not be physically configured as illustrated. Further, the specific form of distribution / integration of the devices is not limited to that shown in the figure, and all or a part thereof may be functionally or physically in arbitrary units according to various additions or according to functional loads. It can be configured to be distributed and integrated. Further, in the above-described embodiment, the case where the vehicle ECU 100 performs processing in a stand-alone form has been described as an example. However, the vehicle ECU 100 responds to a request from an ECU configured with a housing separate from the vehicle ECU 100. Information processing may be performed, and the processing result may be returned to the ECU.

  As described above, the vehicle control apparatus according to the present invention can be preferably implemented particularly in the automobile manufacturing industry and is extremely useful.

100 vehicle ECU
102 Control unit
102a Convergence criterion setting part
102b Error margin calculation unit
102c Restriction condition setting part
102d Optimization processing unit
102e Convergence determination unit
102f Vehicle travel control unit 106 Storage unit
106a Road information file

Claims (7)

A vehicle control device including at least a control unit that performs vehicle travel control using an evaluation function,
The control unit
A constraint condition setting means for variably setting a constraint condition according to the convergence criterion value of the evaluation function;
A vehicle control device comprising: The vehicle control device according to claim 1,
The vehicle control apparatus, wherein the constraint condition is a road condition related to road information. The vehicle control device according to claim 2,
The vehicle control apparatus according to claim 1, wherein the road condition is a road part condition related to a road part in which vehicle travel is permitted. In the vehicle control device according to claim 3,
The vehicle control apparatus, wherein the road partial condition is a condition related to a road width. In the vehicle control device according to any one of claims 1 to 4,
The constraint condition setting means is
The vehicle control apparatus characterized by setting the limited constraint condition as the convergence determination reference value increases. The vehicle control device according to claim 4, wherein
The constraint condition setting means is
The vehicle control device, wherein the constraint condition is set so that the road width allowed for the vehicle travel is narrowed as the convergence determination reference value increases. The vehicle control device according to claim 4, wherein
The constraint condition setting means is
The convergence determination criterion is set such that a value obtained by adding the road width that is allowed to travel the vehicle as the constraint condition and an error margin that is an allowable error of the road width is narrower than the actual road width. The vehicle control apparatus characterized in that the constraint condition is set so that the width of the error margin becomes wider as the value becomes larger.

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