JP2008223861A - Vehicle control device - Google Patents

Abstract

In a vehicle that performs control for limiting the shift of a transmission during turning, it is avoided that the shift is limited when the vehicle is running straight.
The frequency of the distance traveled by the wheel speed difference between the left and right wheels calculated based on the wheel speed data is calculated and accumulated every time the wheel speed data is collected, and the maximum frequency of the frequency distribution of the distance frequency is straight ahead. It is determined. Thus, the determination accuracy can be improved by determining the straight travel based on the travel history of the actually traveled vehicle. For example, when there is a diameter difference between the tire diameters of the left and right wheels and the wheel speed difference between the left and right wheels in a straight traveling is ΔVa, the traveling frequency at the wheel speed difference ΔVa is the largest, so the wheel speed difference ΔVa is determined to be straight. By determining, it is possible to improve the determination accuracy of straight travel. Then, by setting the region Fa in which the speed limit is not applied based on the wheel speed difference ΔVa determined to be straight ahead in this way, it is possible to avoid the problem that the speed change is restricted in the straight forward state.
[Selection] Figure 8

Description

  The present invention relates to a vehicle control device that executes a shift-time shift restriction control for limiting a shift during turning in a vehicle equipped with a transmission that shifts power from a drive source and transmits the power to wheels.

  In a vehicle equipped with an engine (internal combustion engine), the gear ratio between the engine and the drive wheel is automatically used as a transmission that properly transmits the torque and rotation speed generated by the engine to the drive wheel according to the running state of the vehicle. Automatic transmissions that are optimally set are known.

  As an automatic transmission mounted on a vehicle, for example, a planetary gear type transmission that sets a gear ratio (gear stage) using a friction engagement element such as a clutch and a brake and a planetary gear device, or a gear ratio is not used. There is a continuously variable transmission (CVT) that adjusts in stages.

  In a vehicle equipped with a planetary gear type automatic transmission, a shift map having a shift line (gear stage switching line) for obtaining an optimum gear stage according to the vehicle speed and throttle opening (or accelerator opening) Is stored in an ECU (Electronic Control Unit) or the like, and a target gear stage is calculated by referring to the shift map based on the vehicle speed and the throttle opening, and is a friction engagement element based on the target gear stage. The gear stage (shift stage) is automatically set by engaging or releasing the clutch element, the brake element, the one-way clutch element, and the like in a predetermined state.

  Moreover, there exists an automatic transmission (MMT: Multi-Mode Manual Transmission) with a manual transmission function as a transmission mounted in a vehicle. The MMT is also called a sequential manual transmission. The manual transmission has an automatic clutch, and a manual mode in which an upshift and a downshift are executed by a driver's shift operation, and an upshift and a downshift are executed according to a shift map. And automatic mode.

In a vehicle equipped with an automatic transmission, if shifting is performed with lateral acceleration applied, dangerous vehicle behavior such as tuck-in and spin may occur. In order to avoid such a point, turning-time shift restriction (prohibition) control is performed to restrict the shift of the automatic transmission when the vehicle turns. In turning limit control during turning, the vehicle turning state is determined by calculating the left-right speed difference of the front wheels or the left-right speed difference of the rear wheels among the four wheels, and the speed difference (absolute value) of the left and right wheels. ) Is equal to or greater than a predetermined threshold value, and there is a method of determining that the vehicle is turning (see, for example, Patent Document 1).
JP-A-1-204852 JP-A-8-244593

  By the way, in the turning determination method for determining turning of the vehicle based on the wheel speed difference between the left and right wheels, if the tire diameter of the left and right wheels is different due to different diameter tires, wear of one wheel, wearing emergency tires, etc., the vehicle goes straight. In spite of the running state, a speed difference occurs between the left and right wheels, and it may be erroneously determined that the vehicle is turning. If such a misjudgment occurs, turning limit control may be performed during straight traveling. In such a situation, for example, the driver may not be able to satisfy the driving demand of the driver because the automatic transmission is not upshifted even though the driver is depressing the accelerator pedal in order to accelerate. .

  Here, as a method of correcting the wheel speed generated by mounting different diameter tires, etc., the average value of the wheel speeds of the four wheels is calculated, and the detected value (raw data) of each wheel speed is calculated with the average value being positive. There is a method of correcting.

  In this correction method, correction can be made when the vehicle is traveling straight ahead, but incorrect correction may occur during steady turning such as when the vehicle is making a steady circular turn or traveling on a large curve. May occur. That is, during steady turning, a wheel speed difference is constantly generated between the left and right wheels, so that if the wheel speed of each wheel is corrected by assuming that the steady deviation due to the steady turning is a deviation due to the diameter difference between the left and right wheels. The wheel speed becomes an incorrect value (false learning). When such an erroneous correction occurs, the straight traveling may be erroneously determined as the turning when the normal turning traveling is shifted to the straight traveling. Therefore, even if this method is adopted, there is a possibility that the shift of the automatic transmission is restricted during straight traveling.

  The present invention has been made in consideration of such a situation, and in a vehicle that performs control for limiting the shift of the transmission when turning, it is possible to avoid the disadvantage that the shift is limited when the vehicle is running straight. An object of the present invention is to provide a vehicle control device.

  The present invention is premised on a vehicle control apparatus that includes a transmission that shifts power from a drive source and transmits the power to wheels, and that executes a shift limitation control during turning that limits the shift of the transmission when the vehicle is turning. In such a vehicle control device, the frequency calculation means for calculating the distance frequency or the time frequency of the physical quantity indicating the straight traveling or turning of the vehicle, the frequency frequency is obtained by accumulating the distance frequency or the time frequency, and It is characterized by comprising setting means for determining that the maximum frequency or average value of the frequency distribution is going straight, and setting a region where the speed limit is not restricted based on the maximum frequency or average value.

  In the present invention, examples of the physical quantity indicating the straight traveling / turning of the vehicle include a wheel speed difference between the left and right wheels, a wheel speed difference between the front and rear wheels, a steering angle, a steering torque, or a lateral acceleration. A distance frequency or a time frequency of straight traveling / turning may be calculated by combining a plurality or all of these physical quantities.

  In the present invention, in the traveling of the vehicle, the traveling frequency in the straight traveling state is the highest and the traveling frequency in the turning state is smaller as the turning degree (steering angle) is larger (the turning degree is higher → the driving frequency is lower). Pay attention and calculate and accumulate distance frequency (or time frequency) of straight travel and turn (for each turn degree) to obtain frequency distribution, and determine straight travel from the maximum frequency (or average value of frequency distribution) Yes. Thus, the accuracy of the straight traveling determination can be improved by determining the straight traveling from the actual traveling history of the vehicle. For example, if there is a diameter difference in the tire diameter of the left and right wheels due to wear of different diameter tires, wear of one wheel, emergency tire mounting, etc., and the wheel speed difference between the left and right wheels is ΔVa in a straight running state, the wheel speed difference ΔVa Therefore, it is possible to improve the accuracy of straight travel determination by determining that the wheel speed difference ΔVa is straight travel.

  Then, by setting the region where the speed limit is not applied with the wheel speed difference ΔVa determined to be straight running in this way as a reference (center), the inconvenience that the speed change of the transmission is restricted during the straight running state is avoided. can do. Further, by performing correction for removing such a steady wheel speed difference ΔVa (steady deviation) caused by mounting different diameter tires or the like, it is possible to improve the accuracy of vehicle turning determination.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic configuration diagram showing an example of a vehicle to which the present invention is applied.

  The vehicle in this example is an FF (front engine / front drive) type vehicle, and includes an engine 1, a torque converter 2, an automatic transmission 3, an electric power steering device (EPS) 4, an ECU 100, and the like. The vehicle control apparatus of the present invention is implemented by a program that is mounted and executed by the ECU 100.

  Further, in the vehicle, the right front wheel 10FR, the left front wheel 10FL, the right rear wheel 10RR, the left rear wheel 10RL (hereinafter, the right front wheel 10FR, the left front wheel 10FL, the right rear wheel 10RR, and the left rear wheel 10RL are simply referred to as “wheel 10”. 4 wheels may be arranged. Of these four wheels 10, the right front wheel 10FR and the left front wheel 10FL are drive wheels driven by the engine 1 and are steered wheels that are steered by the electric power steering device 4.

-Engine-
The engine 1 is a multi-cylinder gasoline engine, for example. The amount of air taken into the engine 1 is adjusted by an electronically controlled throttle valve 11. The throttle valve 11 can electronically control the throttle opening independently of the driver's accelerator pedal operation, and the opening (throttle opening) is detected by the throttle opening sensor 202.

  The throttle opening of the throttle valve 11 is driven and controlled by the ECU 100. Specifically, the optimal intake according to the operating state of the engine 1 such as the engine speed detected by the engine speed sensor 201 (see FIG. 4) and the accelerator pedal depression amount (accelerator opening) of the driver. The throttle opening of the throttle valve 11 is controlled so that the air amount (target intake air amount) can be obtained. More specifically, the actual throttle opening of the throttle valve 11 is detected using the throttle opening sensor 202, and the actual throttle opening becomes the throttle opening (target throttle opening) at which the target intake air amount is obtained. The throttle motor 12 of the throttle valve 11 is feedback controlled so as to match.

  A torque converter 2 and an automatic transmission 3 are connected to the engine 1, and when the engine 1 is driven, the right front wheel 10FR and the left front wheel 10FL, which are driving / steering wheels, are rotationally driven via the drive shaft 5.

-Torque converter-
As shown in FIG. 2, the torque converter 2 includes a pump impeller 21 on the input shaft side, a turbine impeller 22 on the output shaft side, a stator 23 that exhibits a torque amplification function, and a one-way clutch 24. Power is transmitted between the impeller 21 and the turbine impeller 22 via a fluid.

  The torque converter 2 is provided with a lockup clutch 25 that directly connects the input side and the output side. By completely engaging the lockup clutch 25, the pump impeller 21 and the turbine impeller 22 Rotate together. Further, by engaging the lock-up clutch 25 in a predetermined slip state, the turbine impeller 22 rotates following the pump impeller 21 with a predetermined slip amount during driving. The torque converter 2 and the automatic transmission 3 are connected by a rotating shaft.

-Automatic transmission-
As shown in FIG. 2, the automatic transmission 3 includes a first transmission unit 31 mainly composed of a single pinion type first planetary gear device 301, a single pinion type second planetary gear device 302, and a double pinion type. The planetary gear which has the 2nd speed change part 32 comprised mainly by the 3rd planetary gear apparatus 303 of this on the coaxial line, changes the rotation of the input shaft 33, transmits it to the output shaft 34, and outputs it from the output gear 35 Type multi-stage transmission. The output gear 35 is connected to a differential gear device mounted on the vehicle directly or via a counter shaft. Since the automatic transmission 3 is configured substantially symmetrically with respect to the center line, the lower half of the center line is omitted in FIG.

  The first planetary gear device 301 constituting the first transmission unit 31 includes three rotating elements, a sun gear S 1, a carrier CA 1, and a ring gear R 1, and the sun gear S 1 is coupled to the input shaft 33. Further, the sun gear S1 is decelerated and rotated with respect to the input shaft 33 using the carrier CA1 as an intermediate output member when the ring gear R1 is fixed to the housing 36 via the third brake B3.

  In the second planetary gear device 302 and the third planetary gear device 303 constituting the second transmission unit 32, four rotating elements RM1 to RM4 are configured by being partially connected to each other. Specifically, the first rotating element RM1 is constituted by the sun gear S3 of the third planetary gear unit 303, and the ring gear R2 of the second planetary gear unit 302 and the ring gear R3 of the third planetary gear unit 303 are connected to each other. A second rotation element RM2 is configured. Further, the carrier CA2 of the second planetary gear device 302 and the carrier CA3 of the third planetary gear device 303 are connected to each other to constitute a third rotating element RM3. The fourth rotating element RM4 is configured by the sun gear S2 of the second planetary gear unit 302.

  In the second planetary gear device 302 and the third planetary gear device 303, the carriers CA2 and CA3 are configured by a common member, and the ring gears R2 and R3 are configured by a common member. Further, the pinion gear of the second planetary gear unit 302 is a Ravigneaux type planetary gear train that also serves as the second pinion gear of the third planetary gear unit 303.

  The first rotating element RM1 (sun gear S3) is integrally connected to the carrier CA1 of the first planetary gear device 301 that is an intermediate output member, and is selectively connected to the housing 36 by the first brake B1 to stop rotation. Is done. The second rotating element RM2 (ring gears R2 and R3) is selectively connected to the input shaft 33 via the second clutch C2, and selectively connected to the housing 36 via the one-way clutch F1 and the second brake B2. The rotation is stopped.

  The third rotation element RM3 (carriers CA2 and CA3) is integrally connected to the output shaft 34. The fourth rotation element RM4 (sun gear S2) is selectively coupled to the input shaft 33 via the first clutch C1.

  Note that. Each of the first clutch C1, the second clutch C2, the first brake B1, the second brake B2, and the third brake B3 is a multi-plate hydraulic friction engagement device that frictionally engages with a hydraulic cylinder.

  In the automatic transmission 3 described above, the first clutch C1, the second clutch C2, the first brake B1, the second brake B2, the third brake B3, and the one-way clutch F1, which are friction engagement elements, are in a predetermined state. The gear stage is set by being engaged or released.

  The automatic transmission 3 is provided with a shift lever operated by a driver. By operating the shift lever, for example, a P range (parking range), an R range (reverse travel range), and an N (neutral range). ), D range (forward travel range), etc.

  FIG. 3 is an engagement table for explaining the engagement operation of the clutch and brake for establishing each gear stage of the automatic transmission 3, wherein “◯” represents engagement and “×” represents release. Yes.

  As shown in FIG. 3, in the automatic transmission 3, the first gear (1st) is established by engaging the first clutch C1. The shift (1st → 2nd) from the first speed gear stage (1st) to the second speed gear stage (2nd) is achieved by engaging the first brake B1.

  The speed change (2nd → 3rd) from the second gear (2nd) to the third gear (3rd) is achieved by releasing the first brake B1 and engaging the third brake B3. The shift (3rd → 4th) from the third gear (3rd) to the fourth gear (4th) is achieved by releasing the third brake B3 and engaging the second clutch C2.

  The shift (4th → 5th) from the fourth gear (4th) to the fifth gear (5th) is achieved by releasing the first clutch C1 and engaging the third brake B3. The shift (5th → 6th) from the fifth gear (5th) to the sixth gear (6th) is achieved by releasing the third brake B3 and engaging the first brake B1.

  The reverse gear (Rev) is established by engaging the second brake B2 and the third brake B3 together.

Note that the gear ratios of the gears of the automatic transmission 3 are the gear ratios of the first planetary gear unit 301, the second planetary gear unit 302, and the third planetary gear unit 303 (= the number of teeth of the sun gear / the number of ring gears). The number of teeth) is appropriately determined according to ρ _UD , ρ _S , ρ _D.

  Engagement / release of the friction engagement elements of the automatic transmission 3 is controlled by a hydraulic control circuit 300 (see FIG. 4).

  The hydraulic control circuit 300 is provided with a linear solenoid valve, an on / off solenoid valve, and the like. By switching the hydraulic circuit by controlling excitation / non-excitation of the linear solenoid valve and the on / off solenoid valve, the hydraulic transmission circuit 3 Engagement / release of frictional engagement elements such as clutches and brakes can be controlled. Excitation / non-excitation of the linear solenoid valve and the on / off solenoid valve of the hydraulic control circuit 300 is controlled by a solenoid control signal (instructed hydraulic signal) from the ECU 100.

-Electric power steering device-
The electric power steering device 4 includes a steering wheel (handle) 41, a steering shaft 42, a steering angle sensor 43, a steering torque sensor 44, an assist motor 45, a rack and pinion mechanism 46, and the like. A drive shaft 5 is coupled to the rack shaft of the rack and pinion mechanism 46. One end of a steering shaft 42 is connected to the steering wheel 41, and a rack and pinion mechanism 46 is connected to the other end of the steering shaft 42.

  The steering angle sensor 43 detects the rotation angle of the steering shaft 42. The steering torque sensor 44 detects torque acting on the steering shaft 42. The rotation angle of the steering shaft 42 detected by the steering angle sensor 43, that is, the steering angle, and the steering torque detected by the steering torque sensor 44 are input to the ECU 100. The ECU 100 calculates an auxiliary steering force to be added to the steering system based on the steering angle and the steering torque, and drives and controls the assist motor 45 based on the calculated auxiliary steering force.

  On the other hand, each wheel 10 is provided with brake devices 8FR, 8FL, 8RR, 8RL (hereinafter, each brake device 8FR, 8FL, 8RR, 8RL may be simply referred to as “brake device 8”). The brake devices 8FR, 8FL, 8RR, and 8RL include a brake disc and a caliper that incorporates a brake pad and a wheel cylinder. Each wheel cylinder of the brake devices 8FR, 8FL, 8RR, 8RL is connected to a hydraulic control circuit 200 of the braking system via a brake pipe. Each wheel cylinder is also connected to the master cylinder 7 via a brake pipe and a hydraulic control circuit 200. The hydraulic control circuit 200 includes a hydraulic pump and a solenoid valve. Driving of the hydraulic pump of the hydraulic control circuit 200, opening and closing of the solenoid valve, and the like are controlled by the ECU 100.

  In the braking system of this example, when the brake pedal 6 is operated by the driver during normal braking, the pressure in the master cylinder 7 rises, and this pressure rise is applied to each brake device via the brake pipe and the hydraulic control circuit 200. It is transmitted to the wheel cylinders 8FR, 8FL, 8RR, 8RL, and the pressure in each wheel cylinder rises. Thus, when the hydraulic pressure in the wheel cylinder rises, the brake pad is pressed against the brake disc, and each wheel 10 connected to the brake disc is braked by the frictional force generated by the pressing force.

  Wheel speed sensors 20FR, 20FL, 20RR, 20RL for detecting the respective wheel speeds are arranged on the right front wheel 10FR, the left front wheel 10FL, the right rear wheel 10RR, and the left rear wheel 10RL. The output signals of the wheel speed sensors 20FR, 20FL, 20RR, 20RL are input to the ECU 100.

-ECU-
As shown in FIG. 4, the ECU 100 includes a CPU 101, a ROM 102, a RAM 103, a backup RAM 104, and the like.

  The ROM 102 stores various control programs, maps that are referred to when the various control programs are executed, and the like. The CPU 101 executes arithmetic processing based on various control programs and maps stored in the ROM 102. The RAM 103 is a memory that temporarily stores calculation results of the CPU 101, data input from each sensor, and the like. The backup RAM 104 is a non-volatile memory that stores data to be saved when the engine 1 is stopped. is there.

  The CPU 101, ROM 102, RAM 103, and backup RAM 104 are connected to each other via a bus 106 and to an interface 105.

  An interface 105 of the ECU 100 includes an engine speed sensor 201, a throttle opening sensor 202, an accelerator opening sensor 203 that detects the opening of the accelerator pedal, a brake pedal sensor 204 disposed in the vicinity of the brake pedal 6, and a lateral acceleration sensor. 205, a steering angle sensor 43, a steering torque sensor 44, wheel speed sensors 20FR, 20FL, 20RR, 20RL and the like are connected, and signals from these sensors are input to the ECU 100.

  The ECU 100 executes various controls of the engine 1 including throttle opening control of the engine 1 (control of the throttle motor 12), fuel injection amount control, ignition timing control, and the like based on the output signals of the various sensors described above. .

  The ECU 100 also outputs a solenoid control signal (instructed hydraulic signal) to the hydraulic control circuit 300 of the automatic transmission 3. Based on this solenoid control signal, the linear solenoid valve and the on / off solenoid valve of the hydraulic control circuit 300 are controlled, and friction engagement elements such as a clutch and a brake of the automatic transmission 3 are configured so as to constitute a predetermined gear stage. Engaged or released to a predetermined state. The ECU 100 also performs drive control of the assist motor 45 and the brake hydraulic control circuit 200 described above.

  Further, the ECU 100 executes the following “shift control” and “shift restriction condition setting process”.

-Shift control-
First, a shift map used for the shift control of this example will be described with reference to FIG.

  The shift map shown in FIG. 5 is a map in which a vehicle speed and a throttle opening are used as parameters, and a plurality of areas for obtaining an appropriate gear stage are set according to the vehicle speed and the throttle opening. Is stored within. Each region of the shift map is partitioned by a plurality of shift lines (gear stage switching lines). In the shift map shown in FIG. 5, only the upshift line is shown.

  Next, the basic operation of the shift control will be described.

  The ECU 100 reads the wheel speeds VFR, VFL, VRR, VRL of each wheel 10 based on the output signals of the wheel speed sensors 20FR, 20FL, 20RR, 20RL, and the vehicle speed ( (Average vehicle speed) is calculated, the throttle opening is calculated from the output signal of the throttle opening sensor 202, and the target gear stage is calculated with reference to the shift map of FIG. 5 based on the vehicle speed and the throttle opening. Then, the target gear stage is compared with the current gear stage to determine whether or not a speed change operation is necessary.

  If the result of the determination indicates that shifting is not required (when the target gear stage and the current gear stage are the same and the gear stage is set appropriately), a solenoid control signal (hydraulic command) is used to maintain the current gear stage. Signal) to the hydraulic control circuit 300 of the automatic transmission 3.

  On the other hand, when the target gear stage and the current gear stage are different, shift control is performed. For example, when the driving state of the vehicle changes from the state where the gear stage of the automatic transmission 3 is running at the “fourth speed” state, for example, the point A changes to the point B shown in FIG. Since the change occurs across the shift line [4 → 5], the target gear stage calculated from the shift map is “5-speed”, and the solenoid control signal (hydraulic command signal) for setting the 5-speed gear stage is automatically shifted. Output to the hydraulic control circuit 300 of the machine 3 to perform a shift (4 → 5-up shift) from the fourth gear to the fifth gear.

-Shift limit setting process-
Next, the process for setting the shift restriction condition will be described. FIG. 6 is a flowchart showing an example of a control routine for setting processing of the shift restriction condition. The control routine shown in FIG. 6 is executed in ECU 100.

  First, in step ST1, the front wheel left and right wheel speeds VFR and VFL are read from the output signals of the wheel speed sensor 20FR for the right front wheel 10FR and the wheel speed sensor 20FL for the left front wheel 10FL.

  In step ST2, a wheel speed difference (VFR−VFL) between the wheel speed VFR of the right front wheel 10FR and the wheel speed speed VFL of the left front wheel is calculated.

  In step ST3, the distance frequency traveled by the wheel speed difference (VFR−VFL) calculated in step ST2 is calculated and accumulated. Specifically, assuming that the wheel speed difference (VFR−VFL) = ΔVx, the frequency of the distance traveled by a certain wheel speed difference ΔVx1, Vx2,..., Or Vxn (including ΔVx = 0) is used as wheel speed data. Is calculated every time it is collected, and the distance frequency is accumulated.

  For the processing of the above steps ST1 to ST3 (loading of wheel speed data → frequency calculation / accumulation processing of distance traveled by each wheel speed difference), for example, the number of data to the extent that a frequency distribution as shown in FIG. 7 is obtained is collected. The process is repeated until possible, and the process proceeds to step ST5 when the accumulation of the distance frequency is completed (when the determination result of step ST4 is affirmative).

  In step ST5, it is determined that the highest frequency (peak) of the frequency distribution shown in FIG. 7 is going straight, and the region Fa where no speed limit is applied is set with the highest frequency as a reference (center). The area Fa where the shift limitation is not applied is, for example, the speed change of the automatic transmission 3 in a state where the vehicle body is subjected to lateral acceleration with the turning radius of the vehicle body (the wheel speed difference or the wheel speed ratio of the left and right wheels) and the vehicle speed as parameters. A region where the dangerous behavior such as tuck-in or spin does not occur (allowable wheel speed difference) may be obtained empirically in advance through experiments and calculations, and set based on the result.

  It should be noted that the frequency distribution shown in FIG. 7 (or FIG. 8 to be described later) is a shift restriction condition map (the number of distances that can be collected every time the travel distance reaches a predetermined distance). Every time the vehicle travels), it is sequentially recorded and updated in the backup RAM 104 of the ECU 100.

  The ECU 100 then calculates the wheel speed difference ΔVx (ΔVx = VFR−VFL) between the current wheel speed VFR of the right front wheel 10FR and the wheel speed speed VFL of the left front wheel after the calculation of the frequency distribution of the distance frequency is completed. When the calculated wheel speed difference ΔVx is small and within the frequency distribution region Fa, dangerous behavior such as tuck-in and spin does not occur, so that the shift restriction is not applied. On the other hand, when the calculated wheel speed difference ΔVx is large and is within the shift restriction region Fb, dangerous behavior such as tuck-in or spin may occur, and thus the shift of the automatic transmission 3 is limited.

  Here, when the tire diameter of the right front wheel 10FR and the tire diameter of the left front wheel 10FL are the same, as shown in FIG. 7, the traveling frequency when the wheel speed difference ΔVx is [ΔVx = 0] is maximized.

  On the other hand, when the tire diameters of the left and right wheels are different from each other due to different diameter tires, wear of one wheel, wearing emergency tires, etc., for example, there is a difference in diameter of [tire diameter of right front wheel 10FR] <[tire diameter of left front wheel 10FL]. As shown in FIG. 8, the traveling frequency becomes maximum when the wheel speed difference ΔVx is [ΔVx = ΔVa]. That is, it can be said that the vehicle travels straight when the wheel speed difference ΔVx is [ΔVx = ΔVa]. Therefore, by determining that the wheel speed difference ΔVa is going straight, it is possible to improve the straight running judgment accuracy even if there is a difference in the tire diameters of the left and right wheels. Then, by setting a region Fa in which the speed limit is not applied with reference to the wheel speed difference ΔVa determined to go straight in this way, the speed change of the automatic transmission 3 is restricted in the straight running state. The inconvenience can be avoided.

  Further, by performing correction for removing such a steady wheel speed difference ΔVa (steady deviation) caused by mounting different diameter tires or the like, it is possible to improve the accuracy of vehicle turning determination. Specifically, for example, correction coefficients set for the output signals (raw data of VFR and VFL) of the wheel speed sensor 20FR of the right front wheel 10FR and the wheel speed sensor 20FL of the left front wheel 10FL are set to the right and left wheels. By performing learning correction so that the speed difference ΔVa (steady deviation) becomes [ΔVa → 0], it is possible to correct the steady deviation due to mounting of different diameter tires or the like.

  The frequency distributions shown in FIGS. 7 and 8, etc. are sequentially stored and updated every time the travel distance reaches a predetermined number of distances as a shift restriction condition map. Even if the difference between the tire diameters of the wheels increases (decreases), the error of the change can be corrected by learning. Further, even when a new diameter difference occurs due to the installation of an emergency tire or the like, the learning correction can be similarly performed.

-Other embodiments-
In the above example, the maximum frequency of the frequency distribution of the distance frequency is determined to be straight, and the region Fa where the speed limit is not applied is set. For example, as illustrated in FIG. When two or more (two places) appear and it is difficult to discriminate them, it may be determined that the average value of the frequency distribution is straight, and the region Fa where no shift restriction is applied is set.

  In the above example, the distance frequency of straight travel / turning is calculated based on the wheel speed difference between the left and right front wheels. However, the present invention is not limited to this, and the distance frequency of straight travel / turning is calculated based on the wheel speed difference between the left and right rear wheels. May be calculated. Further, when the vehicle turns, a wheel speed difference also occurs between the front and rear wheels. Therefore, the straight / turning distance frequency may be calculated based on the wheel speed difference before and after the right wheel or before and after the left wheel.

  In the above example, the distance frequency for straight travel / turning is calculated based on the difference between the left and right (front / rear) wheel speeds, but the distance frequency for straight travel / turning may be calculated using other physical quantities. Specifically, using the steering angle read from the output signal of the steering angle sensor 43, the steering torque read from the output signal of the steering torque sensor 44, or the physical quantity of the lateral acceleration read from the output signal of the lateral acceleration sensor 205, the vehicle travels straight. -You may make it calculate the distance frequency of turning. Furthermore, the distance frequency of the straight traveling / turning may be calculated by combining a plurality of or all of the physical quantities of the left / right (front / rear) wheel speed difference, the steering angle, the steering torque, or the lateral acceleration.

  When a physical quantity indicating straight travel or turning is used as the steering angle, the output frequency (raw data of the steering angle) An of the steering angle sensor 43 is not [An = 0], but a traveling frequency at a certain value [An = Ana]. Since the output signal of the rudder angle sensor 43 can be determined to be deviated from the actual state (straight forward), the output signal of the rudder angle sensor 43 is offset by an amount corresponding to the above Ana. Learning correction may be performed.

  Similarly, when the output signal (raw data of steering torque) Tr of the steering torque sensor 44 is not [Tr = 0] but the traveling frequency at a certain value [Tr = Tra] is the highest, the steering torque sensor 44 The learning correction may be performed such that the output signal is offset by the amount corresponding to the Tra. Further, in the case of the lateral acceleration sensor 205, similarly, when the output signal (raw data of lateral acceleration) G is not [G = 0] but the traveling frequency is maximum at a certain value [G = Ga], the lateral acceleration is You may make it perform the learning correction | amendment which offsets the output signal of the sensor 205 by the said Ga equivalent.

  In the above example, the frequency distribution is calculated by calculating the frequency frequency of straight / turning, but the present invention is not limited to this, and the frequency distribution is calculated by calculating the time frequency of straight / turning. The maximum frequency (average value) of the frequency distribution of frequency may be determined, and the region Fa where the shift restriction of the automatic transmission 3 is not applied may be set.

  In the above example, an example in which the present invention is applied to a vehicle equipped with an automatic transmission with five forward speeds is shown. However, the present invention is not limited to this, and the planetary gear type automatic at any other speed stage. It can also be applied to a vehicle equipped with a transmission. Further, the present invention is not limited to the planetary gear type automatic transmission, and the present invention can be applied to a vehicle on which another transmission such as an automatic transmission (MMT) with a manual transmission function is mounted.

  The present invention is not limited to FF (front engine / front drive) type vehicles, but can also be applied to FR (front engine / rear drive) type vehicles and four-wheel drive vehicles.

  The present invention is also applicable to a vehicle that performs ABS (Antilock Break System), vehicle behavior stabilization control device (VSC), roll suppression by active suspension control, yaw control by four-wheel drive force control, and the like. Can do.

  In the above example, the present invention is applied to a vehicle equipped with a gasoline engine. However, the present invention is not limited to this and can be applied to control of a vehicle equipped with another engine such as a diesel engine. It is. The present invention is also applicable to a hybrid vehicle equipped with an engine (internal combustion engine) and an electric motor (for example, a traveling motor or a generator motor) as drive sources.

It is a schematic structure figure showing an example of a vehicle to which the present invention is applied. It is a schematic block diagram of the automatic transmission mounted in the vehicle of FIG. 3 is an operation table of the automatic transmission shown in FIG. 2. It is a block diagram which shows the structure of control systems, such as ECU. It is a figure which shows the shift map used for shift control. It is a flowchart which shows an example of the setting process of a speed limit condition. It is a figure which shows an example of frequency distribution of the distance frequency of a straight advance and a turn. It is a figure which shows the other example of the frequency distribution of the distance frequency of rectilinear advance / turn. It is a figure which shows another example of the frequency distribution of the distance frequency of rectilinear advance / turn.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Engine 2 Torque converter 3 Automatic transmission 4 Electric power steering device 43 Steering angle sensor 44 Steering torque sensor 5 Drive shaft 6 Brake pedal 8FR, 8FL, 8RR, 8RL Brake device 10FR Right front wheel 10FL Left front wheel 10RR Right rear wheel 10RL Left rear Wheel 20FR, 20FL, 20RR, 20RL Wheel speed sensor 100 ECU
205 Lateral acceleration sensor

Claims (2)

A vehicle control device that includes a transmission that shifts power from a drive source and transmits the power to wheels, and that performs a turning-time shift restriction control that restricts a shift of the transmission when the vehicle turns,
A frequency calculation means for calculating a distance frequency or a time frequency of a physical quantity indicating a straight traveling or turning of the vehicle, and a frequency distribution is obtained by accumulating the distance frequency or the time frequency, and a maximum frequency or an average value of the frequency distribution is set as a straight line A vehicle control apparatus comprising: setting means for determining and setting a region in which the speed limit is not restricted based on the highest frequency or average value. The vehicle control device according to claim 1,
The frequency calculating means calculates a distance frequency or a time frequency of one physical quantity or a plurality of physical quantities among a physical speed quantity difference between a right and left wheel speed difference, a front and rear wheel speed difference, a steering angle, a steering torque, or a lateral acceleration. A control apparatus for a vehicle.

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