JP2010000946A - Target track generation method and vehicle travel controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a target track generation method and a vehicle travel controller for mounting a computation program for generation of an ideal track using a characteristic of a mechanism as an evaluation function and for obtaining a solution within a limited computation time, in the mechanism having the evaluation function set thereto in accordance with driver's request items such as comfort and gas milage and having a characteristic in which there are two optimum ranges in vehicle control. <P>SOLUTION: If a plurality of optimum ranges of optimum computation for the request items of a driver, the evaluation function is set to an equation approximated by a quartic equation of one variable. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a target travel locus generation method and a vehicle travel control device.

  Conventionally, in vehicle travel control, a control method for causing a vehicle to travel according to a predetermined target has been developed.

  For example, in the vehicle travel control method described in Patent Document 1, when a vehicle is automatically traveled, a vehicle that determines a target position with respect to the time of the host vehicle and performs feedback control so that a positional deviation between the target position and the actual position becomes small. A traveling control method is disclosed.

  Further, in the vehicle travel control method described in Non-Patent Document 1, the corner where the automobile is determined in consideration of the friction coefficient of the tire, the engine output, the downforce, and the travel resistance by the numerical calculation using the optimal control theory is the shortest. Control methods such as line taking for passing in time and speed change are disclosed.

JP 2000-177428 A Takehiko Fujioka, Daimasa Emori “Theoretical Study on the Shortest Time Cornering Method-4th Report: Introduction of Road Conditions Using State Quantity Inequality Constraints” Vol. 24 No. 3 (P.106-111) July 1993

  However, there is a mechanism having a characteristic that there are two optimum regions in vehicle travel control (for example, there is an optimum region on the acceleration side and deceleration side in the fuel efficiency control of a hybrid vehicle). However, the above-described conventional technique has a problem that it cannot be formulated.

  In particular, the vehicle travel control method described in Patent Document 1 is limited to reducing the positional deviation between the target position and the actual position with respect to a predetermined time, and the evaluation function is formulated as a positional deviation. The problem of one optimum region (position deviation as close to 0 as possible) can be easily formulated, but has a problem that it cannot cope with a mechanism having a plurality of optimum regions.

  Further, in the vehicle travel control method described in Non-Patent Document 1, it is limited to minimizing the passing time of a corner, and since the evaluation function is formulated as a passing time, there is one optimum region (passing time is possible) The problem (a positive value as close to 0 as possible) has a problem that it can be formulated easily, but cannot be formulated for a problem having a plurality of optimum regions.

  The present invention has been made in view of the above, and in a mechanism having characteristics that have two optimal ranges in vehicle control in which an evaluation function is set in accordance with driver requirements such as ride comfort and fuel consumption, the characteristics of the mechanism It is an object of the present invention to provide a target travel locus generation method and a vehicle travel control device that can mount an ideal locus generation calculation program using the evaluation function on a vehicle and obtain a solution in a limited calculation time.

  In order to achieve such an object, a target travel locus generation method according to the present invention is a vehicle target travel locus generation method executed in a vehicle travel control apparatus including at least a control unit, and is executed in the control unit. In the case where there are a plurality of optimum areas for the optimization operation with respect to the driver's required items, an evaluation function setting step for setting the evaluation function to an expression approximated by a quaternary equation of one variable is included.

  According to the present invention, when there are a plurality of optimum areas for optimization operations for the driver's required items, the evaluation function is set to an expression approximated by a quaternary equation of one variable, so that the evaluation function has two minimum values. A function of minimum order can be obtained. As a result, the present invention has the effect of shortening the calculation time without destroying the mechanical characteristics having the two optimum ranges.

  The target travel locus generation method of the present invention is the target travel locus generation method described above, wherein the vehicle travel control device is further connected to an acceleration sensor, and the required item of the driver is a fuel efficiency of a hybrid vehicle. In this case, the evaluation function setting step uses the vehicle acceleration / deceleration detected by the acceleration sensor as the variable.

  According to this invention, the vehicle travel control device is further connected to the acceleration sensor, and when the driver's requirement is the fuel efficiency of the hybrid vehicle, the vehicle acceleration / deceleration detected by the acceleration sensor is used as a variable. In addition, an evaluation function using the fuel efficiency index of the hybrid vehicle as a variable in the longitudinal acceleration can be obtained. As a result, the present invention has an effect that the vehicle traveling control can be performed based on the fuel consumption of the hybrid vehicle.

  The target travel locus generating method of the present invention is the target travel locus generating method described above, wherein the evaluation function setting step includes an acceleration at which engine efficiency is maximized, and a median value of deceleration at which the regenerative brake can be used. , And the approximate expression is set as a constant.

  According to the present invention, since the approximate expression is set with the acceleration at which the engine efficiency is maximized and the median value of the deceleration at which the regenerative brake can be used as constants, it is not necessary to calculate the optimum range of the evaluation function. . As a result, the present invention produces an effect that the calculation time can be reduced and the optimum solution can be obtained when generating the target locus for optimizing the fuel efficiency in the hybrid vehicle.

  The target travel locus generation method of the present invention is the target travel locus generation method described above, wherein the evaluation function includes a square of a difference between the variable and an acceleration at which the engine efficiency is maximized, the variable, It is a product of the square of the difference from the median value of the deceleration at which the regenerative brake can be used.

  According to this invention, the evaluation function is a product of the square of the difference between the variable and the acceleration at which the engine efficiency is maximized, and the square of the difference between the variable and the median deceleration that can be used by the regenerative brake. Therefore, calculation can be performed easily. Thereby, this invention has an effect of shortening calculation time further.

  In addition, the vehicle travel control device of the present invention is a vehicle travel control device including at least a control unit, and the control unit calculates an evaluation function when there are a plurality of optimal regions for optimization calculation for a driver's request item. Evaluation function setting means for setting to an expression approximated by a quaternary equation of one variable is provided.

  According to the present invention, when there are a plurality of optimum areas for optimization operations for the driver's required items, the evaluation function is set to an expression approximated by a quaternary equation of one variable, so that the evaluation function has two minimum values. A function of minimum order can be obtained. As a result, the present invention has the effect of shortening the calculation time without destroying the mechanical characteristics having the two optimum ranges.

  In the vehicle travel control device according to the present invention, the vehicle travel control device is further connected to an acceleration sensor, and the required item of the driver is fuel efficiency of the hybrid vehicle. In this case, the evaluation function setting means uses the vehicle acceleration / deceleration detected by the acceleration sensor as the variable.

  According to this invention, the vehicle travel control device is further connected to the acceleration sensor, and when the driver's requirement is the fuel efficiency of the hybrid vehicle, the vehicle acceleration / deceleration detected by the acceleration sensor is used as a variable. In addition, an evaluation function using the fuel efficiency index of the hybrid vehicle as a variable in the longitudinal acceleration can be obtained. As a result, the present invention has an effect that the vehicle traveling control can be performed based on the fuel consumption of the hybrid vehicle.

  In the vehicle travel control device according to the present invention, in the vehicle travel control device described above, the evaluation function setting means includes an acceleration at which engine efficiency is maximized and a median value of deceleration at which the regenerative brake can be used. The approximate expression is set as a constant.

  According to the present invention, since the approximate expression is set with the acceleration at which the engine efficiency is maximized and the median value of the deceleration at which the regenerative brake can be used as constants, it is not necessary to calculate the optimum range of the evaluation function. . As a result, the present invention produces an effect that the calculation time can be reduced and the optimum solution can be obtained when generating the target locus for optimizing the fuel efficiency in the hybrid vehicle.

  In the target travel locus generation method and the vehicle travel control apparatus according to the present invention, when there are a plurality of optimum regions for optimization calculation with respect to the driver's required items, the evaluation function is set to an equation approximated by a quaternary equation of one variable. Therefore, a function of the minimum order having two minimum values can be obtained as the evaluation function. As a result, the present invention has the effect of shortening the calculation time without destroying the mechanical characteristics having the two optimum ranges.

  Hereinafter, embodiments of a target travel locus generation method, a vehicle travel control device, and a program 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.

  In particular, in the following embodiment, an example in which the present invention is applied to the setting of an evaluation function using the fuel consumption of a hybrid vehicle as a required item will be described. be able to.

[Outline of the present invention]
Hereinafter, the outline | summary of the target driving | running | working locus | trajectory generation method and vehicle driving | running | working control apparatus of this invention is demonstrated, Then, the structure of this invention, a process, etc. are demonstrated in detail.

  The vehicle travel control device of the present invention generally has the following basic features. That is, the vehicle travel control device includes at least a control unit. First, the vehicle travel control device sets the evaluation function to an expression approximated by a quaternary equation of one variable when there are a plurality of optimum regions for optimization calculation with respect to the driver's request item in the control unit. Here, “required items” are travel performance required when the vehicle travels. As an example, the required items are ride comfort, fuel consumption, and the like. Here, the vehicle travel control device may be further connected to the acceleration sensor, and when the driver's requirement item is the fuel efficiency of the hybrid vehicle, the vehicle acceleration / deceleration detected by the acceleration sensor may be used as a variable. Here, the vehicle travel control device may set an approximate expression using a constant that is an acceleration at which engine efficiency is maximized and a median value of deceleration at which the regenerative brake can be used. Here, the vehicle travel control device determines the evaluation function as the square of the difference between the variable and the acceleration at which the engine efficiency is maximum, and the square of the difference between the variable and the median value of the deceleration at which the regenerative brake can be used. It is good also as the product of.

  This is the end of the summary of the present invention.

[Configuration of vehicle travel control device]
First, the configuration of the vehicle travel control device will be described. FIG. 1 is a block diagram showing an example of the configuration of the vehicle travel control device. Only the part relevant to the present invention is conceptually shown. As shown in FIG. 1, this vehicle travel control apparatus is generally configured to include a vehicle control ECU 100, a power train control ECU 20, an engine control ECU 22, a brake control ECU 24, and a steering control ECU 26, and can communicate with an acceleration sensor 90. It is connected.

  In FIG. 1, the vehicle control ECU 100 is schematically configured to include a control unit 102 and a storage unit 106. Here, the control unit 102 is a CPU or the like that comprehensively controls the entire vehicle control ECU 100. The storage unit 106 is a device that stores various databases and tables. Each part of these vehicle control ECU100 is connected so that communication is possible via arbitrary communication paths.

  Moreover, this vehicle travel control apparatus can receive a request item from a driver via the input part (not shown) which was mounted in the vehicle and connected so that communication was possible. As the input unit, a touch panel, a microphone, or the like can be used.

  Various databases and tables (request item table 106a and constant file 106b) stored in the storage unit 106 are storage means such as a fixed disk device. For example, the storage unit 106 stores various programs, tables, files, databases, and the like used for various processes.

  Among these components of the storage unit 106, the request item table 106a is a request item storage unit that stores a request item of the driver and an optimization calculation corresponding to the request item. As an example, the requirement item table 106a may store fuel efficiency as a requirement item and a quaternary equation as a corresponding optimization calculation.

  The constant file 106b is constant storage means for storing a constant that is the root of the evaluation function. As an example, the constant file 106b may store an acceleration that maximizes engine efficiency based on the E / G characteristic data as a constant, and a median value of deceleration that can be used by the regenerative brake based on the regenerative brake characteristic data. .

  In FIG. 1, the control unit 102 has an internal memory for storing a control program such as an OS (Operating System), a program that defines various processing procedures, and necessary data. And the control part 102 performs the information processing for performing various processes by these programs. The control unit 102 includes an evaluation function setting unit 102a and an optimization program execution unit 102b in terms of functional concept.

  Among these, the evaluation function setting unit 102a is an evaluation function setting unit that sets the evaluation function to an expression approximated by a quaternary equation of one variable when there are a plurality of optimal regions for optimization calculation with respect to the requirement items of the driver.

  The optimization program execution unit 102b is an optimization program execution unit that generates a target travel locus of the vehicle that optimizes the driver's request items using the evaluation function, and performs vehicle travel control according to the target travel locus. is there.

  In FIG. 1, the power train control ECU 20 may be configured as a power train control device for driving force demand, or may include an HV-ECU that is a computer for controlling the hybrid system.

  In FIG. 1, an engine control ECU 22 is an electronic control unit that controls the output of the engine and accelerates the vehicle.

  In FIG. 1, a brake control ECU 24 is an electronic control unit that controls a brake actuator and the like, and decelerates the vehicle by operating a hydraulic brake, a regenerative brake, or the like.

  In FIG. 1, a steering control ECU 26 is an electronic control unit that controls a steering actuator and adjusts the traveling direction of the vehicle by turning wheels in cornering traveling or the like.

  Above, description of the structure of this vehicle travel control apparatus is finished.

[Process of target travel locus generation method]
And the target driving | running | working locus | trajectory production | generation method in this Embodiment is demonstrated with reference to FIG. 2 and FIG. Here, FIG. 2 is a flowchart showing the basic processing in the present embodiment, and FIG. 3 is a graph showing an example of the evaluation function in the present embodiment.

  First, as shown in FIG. 2, the control unit 102 of the vehicle control ECU 100 acquires the acceleration a1 that maximizes the engine efficiency of the hybrid vehicle stored in the constant file 106b (step SA-1), and regenerates the hybrid vehicle. An acceleration a2 that is a median value of deceleration at which the brake can be used is acquired (step SA-2). Note that either step SA-1 or step SA-2 may be performed at the same time.

Next, the evaluation function setting unit 102a of the vehicle control ECU 100 uses the vehicle acceleration / deceleration α detected by the acceleration sensor 90 as a variable, and a quaternary equation having the acceleration a1 and the acceleration a2 as roots as an evaluation function f (α). Set (step SA-3).
f (α) = (α−a1) ² (α−a2) ²

  Here, with reference to FIG. 3, a graph showing an example of the evaluation function in the present embodiment will be described. As shown in FIG. 3, the evaluation function obtained in step SA-3 has two optimum values because the acceleration a1 and the acceleration a2 are minimized on a plane with the horizontal axis representing acceleration and the vertical axis representing fuel consumption. It is formulated as an equation of the minimum order having the characteristic that the region exists.

  Returning to FIG. 2 again, the optimization program execution unit 102b of the vehicle control ECU 100 includes a route guidance device (not shown) connected to the planned travel route previously stored in the storage unit 106 and the vehicle control ECU 100 via a network. ) To the target destination trajectory of the vehicle that optimizes the fuel efficiency using the evaluation function based on the route information to the destination obtained from () to (step SA-4).

  Here, the optimization program execution unit 102b sends a control signal to the power train control ECU 20, the engine control ECU 22, the brake control ECU 24, the steering control ECU 26, etc. according to the target travel locus of the vehicle to perform the travel control of the vehicle. Good. Specifically, as an example, the power train control ECU 20 may perform driving force distribution control between the engine and the motor so that fuel efficiency is optimized. Further, the engine control ECU 22 may perform control of fuel injection, ignition timing, and the like so that engine efficiency in traveling on the target travel locus is optimized. Further, the brake control ECU 24 may perform the sharing of the braking force between the hydraulic brake and the regenerative brake, the braking control for each wheel, or the like so that the vehicle travels on the target travel locus. The steering control ECU 26 may perform control or the like for assisting the steering torque with respect to the steering operation of the driver so that the vehicle travels on the target travel locus.

  This is the end of the description of the target travel locus generation method.

[Other embodiments]
Although the embodiments of the present invention have been described so far, the present invention is not limited to the above-described embodiments, but can be applied to various different embodiments within the scope of the technical idea described in the claims. It may be implemented. For example, the present invention may be applied in a simulator or the like. In this case, the optimization program execution unit 102b may display the target travel locus of the vehicle on a display unit (not shown) to guide the driver's driving. Here, as the display unit, a speaker may be used in addition to the monitor.

  Further, for example, in the present embodiment, the example in which the evaluation function is applied with the fuel consumption of the hybrid vehicle as a required item has been described, but the required item may be a ride comfort of the vehicle.

  In addition, among the processes described in the embodiment, all or part of the processes described as being automatically performed can be performed manually, or the processes described as being performed manually can be performed. All or a part can be automatically performed by a known method.

  In addition, the processing procedures, control procedures, specific names, information including parameters such as registration data for each processing, and database configuration shown in the above documents and drawings may be arbitrarily changed unless otherwise specified. Can do.

  Further, with respect to the vehicle travel control apparatus shown in FIG. 1, each illustrated component is functionally conceptual and does not necessarily need to be physically configured as illustrated.

  For example, the processing functions provided in each device of the vehicle control ECU 100, particularly the processing functions performed by the control unit 102, are all interpreted or executed by a CPU (Central Processing Unit) and the CPU. It may be realized by a program or hardware based on wired logic. The program is recorded on a recording medium described later, and is mechanically read by the vehicle control ECU 100 as necessary. In other words, the storage unit 106 such as ROM or HD stores a computer program for performing various processes by giving instructions to the CPU in cooperation with an OS (Operating System). This computer program is executed by being loaded into the RAM, and constitutes a control unit in cooperation with the CPU.

  The computer program may be stored in an application program server connected to the vehicle control ECU 100 via an arbitrary network, and may be downloaded in whole or in part as necessary. .

  The program according to the present invention can also be stored in a computer-readable recording medium. Here, the “recording medium” refers to any “portable physical medium” such as a flexible disk, a magneto-optical disk, a ROM, an EPROM, an EEPROM, a CD-ROM, an MO, and a DVD, or a LAN, WAN, or Internet. It includes a “communication medium” that holds the program in a short period of time, such as a communication line or a carrier wave when the program is transmitted via a network represented by

  The “program” is a data processing method described in an arbitrary language or description method, and may be in any format such as source code or binary code. The “program” is not necessarily limited to a single configuration, but is distributed in the form of a plurality of modules and libraries, or in cooperation with a separate program represented by an OS (Operating System). Including those that achieve the function. Note that a well-known configuration and procedure can be used for a specific configuration for reading a recording medium, a reading procedure, an installation procedure after reading, and the like in each device described in the embodiment.

  Various databases and the like (request item table 106a and constant file 106b) stored in the storage unit 106 are storage means such as a memory device such as a RAM and a ROM, a fixed disk device such as a hard disk, a flexible disk, and an optical disk. Stores processing, various programs, tables, databases, web page files, and the like.

  Furthermore, the specific form of the vehicle travel control device distribution / integration is not limited to that shown in the figure, and all or a part thereof can function in arbitrary units according to various additions or according to the functional load. Can be distributed or integrated physically or physically.

  As described above in detail, according to the present invention, in a mechanism having a characteristic in which there are two optimum regions for vehicle control in which an evaluation function is set in accordance with driver requirements such as ride comfort and fuel consumption, the mechanism Since an ideal trajectory generation calculation program using the characteristics of the above as an evaluation function is mounted on a vehicle, a target travel trajectory generation method and a vehicle travel control device that can obtain a solution in a limited calculation time can be provided. It can be used for industries.

It is a block diagram which shows an example of a structure of the vehicle travel control apparatus with which this invention is applied. It is a flowchart which shows the process of the target driving | running | working locus generation method in this Embodiment. It is a graph which shows an example of the evaluation function in this Embodiment.

Explanation of symbols

20 Powertrain control ECU
22 Engine control ECU
24 Brake control ECU
26 Steering control ECU
90 Acceleration sensor 100 Vehicle control ECU
102 Control unit
102a Evaluation function setting unit
102b Optimization program execution unit
106 Storage unit
106a Request item table
106b Constant file

Claims (7)

A vehicle target travel locus generation method executed in a vehicle travel control apparatus including at least a control unit,
Executed in the control unit,
An evaluation function setting step of setting an evaluation function to an expression approximated by a quaternary equation of one variable when there are a plurality of optimization regions for optimization operations for a driver request item,
Target travel locus generation method. The target travel locus generating method according to claim 1,
The vehicle travel control device is further connected to an acceleration sensor,
When the requirement item of the driver is fuel efficiency of a hybrid vehicle,
The evaluation function setting step includes:
The vehicle acceleration / deceleration detected by the acceleration sensor is used as the variable.
Target travel locus generation method. In the method for generating a target travel locus according to claim 2,
The evaluation function setting step includes:
Acceleration that maximizes engine efficiency,
The median deceleration for which the regenerative brake can be used,
The approximate expression is set as a constant.
Target travel locus generation method. In the method for generating a target travel locus according to claim 3,
The evaluation function is
The square of the difference between the variable and the acceleration at which the engine efficiency is maximized;
The square of the difference between the variable and the median deceleration that can be used by the regenerative brake;
It is a product of
Target travel locus generation method. A vehicle travel control device including at least a control unit,
The controller is
When there are a plurality of optimum areas for optimization operations with respect to the driver's required items, the evaluation function setting means is provided for setting the evaluation function to an expression approximated by a quaternary equation of one variable.
Vehicle travel control device. In the vehicle travel control device according to claim 5,
The vehicle travel control device is further connected to an acceleration sensor,
When the requirement item of the driver is fuel efficiency of a hybrid vehicle,
The evaluation function setting means includes
The vehicle acceleration / deceleration detected by the acceleration sensor is used as the variable.
Vehicle travel control device. In the vehicle travel control device according to claim 6,
The evaluation function setting means includes
Acceleration that maximizes engine efficiency,
The median deceleration for which the regenerative brake can be used,
The approximate expression is set as a constant.
Vehicle travel control device.

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