JP2010023803A - Device and method for controlling vehicle - Google Patents

Abstract

An object of the present invention is to determine whether or not a vehicle is turning while suppressing an increase in cost and to control the behavior of the vehicle with high accuracy.
The ECU is turning (YES in S100), the running resistance is less than or equal to a predetermined value D, and the amount of time change of the running resistance is less than or equal to a predetermined value E. In some cases (YES in S102), if the amount of time change in the absolute value of the difference between the left and right wheel speeds is equal to or smaller than a predetermined value F (YES in S104), it is determined that the vehicle is traveling straight ahead. Step (S106) and when the vehicle is not turning (NO in S100), the running resistance is equal to or greater than a predetermined value A, and the time change amount of the running resistance is equal to or greater than a predetermined value B. (YES in S110), if the amount of time change of the absolute value of the left and right wheel speed difference is equal to or greater than a predetermined value C (YES in S112), it is determined that the vehicle is turning. Including a step (S114) To run free.
[Selection] Figure 5

Description

  The present invention relates to a technique for determining whether or not a vehicle is turning and controlling the behavior of the vehicle using the determination result, and in particular, whether or not the vehicle is turning based on the running resistance of the vehicle and the left and right wheel speeds. The present invention relates to a technique for determining whether or not.

  Conventionally, a technique for controlling the behavior of a vehicle in accordance with the traveling state of the vehicle is known. For example, Japanese Patent Laying-Open No. 2006-256368 (Patent Document 1) discloses a vehicle that appropriately controls both the stabilizer force of the torsional rigidity variable stabilizer device and the damping force of the variable damping force shock absorber according to the roll condition of the vehicle. A roll control apparatus is disclosed. The roll control device for a vehicle suppresses and controls the roll of the vehicle by controlling the roll suppression control amount by the damping force of the damping characteristic variable damping force generating means and the roll suppression control amount by the stabilizer force of the torsional stiffness variable stabilizer device. . The vehicle roll control device has a damping characteristic of the damping force generating means compared with a means for determining a rate of change of the roll amount of the vehicle and a rate of change of the roll amount when the rate of change of the roll amount is large. And roll suppression control amount control means for controlling to the high damping side and lowering the torsional rigidity of the stabilizer device.

According to the vehicle roll control device disclosed in the above-mentioned publication, it is possible to ensure effective suppression control of the vehicle roll, and to reduce the energy consumed by the stabilizer device by reducing the torsional rigidity of the stabilizer device. Further, when the rate of change of the roll amount is small, the damping characteristic of the damping force generating means is not controlled to the high damping side, and therefore it is possible to reliably avoid the deterioration of the riding comfort of the vehicle.
JP 2006-256368 A

  By the way, when controlling the behavior of the vehicle, it is necessary to accurately determine whether or not the vehicle is turning. However, in order to determine whether or not the vehicle is turning, it is necessary to separately provide components such as navigation and a steering angle sensor, for example. Therefore, there is a problem that the cost increases. It is also conceivable to determine whether or not the vehicle is turning based on the wheel speed of each wheel of the vehicle, but if the wheel slips due to the friction coefficient or state of the road surface, the vehicle is turning. It cannot be determined with high accuracy.

  In the vehicle roll control device disclosed in the above-mentioned publication, only the roll amount, which is one of the elements indicating the behavior of the vehicle, is detected, and the above-described problems cannot be solved.

  The present invention has been made in order to solve the above-described problems, and an object of the present invention is to determine whether or not the vehicle is turning while suppressing an increase in cost and to accurately determine the behavior of the vehicle. It is an object of the present invention to provide a control device and a control method for a vehicle that are highly controlled.

  In the vehicle control device according to the first invention, the vehicle has left and right wheels. This control device calculates a running resistance calculating means for calculating a running resistance acting in a direction opposite to the traveling direction when the vehicle runs, and calculates a time change amount of the running resistance based on the calculated running resistance. And means for calculating the amount of time change of the absolute value of the wheel speed difference between the left and right wheels based on the wheel speeds of the left and right wheels, and the running resistance is not less than a predetermined first value. When the time change amount of the running resistance is equal to or greater than a predetermined second value and the time change amount of the absolute value of the wheel speed difference is equal to or greater than a predetermined third value, the vehicle It includes a determination unit for determining that the vehicle is turning, and a control unit for controlling the vehicle based on a determination result by the determination unit. A vehicle control method according to a seventh aspect has the same configuration as the vehicle control apparatus according to the first aspect.

  According to the first invention, the running resistance is greater than or equal to a predetermined first value, the time change amount of the running resistance is greater than or equal to a predetermined second value, and an absolute difference in wheel speed is obtained. When the time variation of the value is equal to or greater than a predetermined third value, the running resistance tends to increase and the difference in rotational speed between the left and right wheel speeds is increasing, so the vehicle is turning. It can be determined. Therefore, for example, compared with the case where it is determined whether or not the vehicle is turning only by the wheel speed, it is possible to suppress the determination accuracy from deteriorating even when the wheel slips. That is, it can be accurately determined whether or not the vehicle is turning. Therefore, the behavior of the vehicle can be controlled with high accuracy by controlling the vehicle based on the determination result of whether or not the vehicle is turning. Further, since the running resistance can be calculated using a detection device (for example, a wheel speed sensor, an engine speed sensor, and a throttle position sensor) that is generally provided in the vehicle, it is determined whether or not the vehicle is turning. Since it is not necessary to provide new parts separately for the determination, an increase in cost due to an increase in the number of parts can be suppressed. Therefore, it is possible to provide a vehicle control device and a control method for determining whether or not the vehicle is turning while controlling an increase in cost and controlling the behavior of the vehicle with high accuracy.

  In addition to the configuration of the first invention, the vehicle control device according to the second invention further includes a state detection means for detecting the running state of the vehicle related to the running resistance. The running resistance calculating means calculates the running resistance based on the detected running state. A vehicle control method according to an eighth aspect has the same configuration as the vehicle control apparatus according to the second aspect.

  According to the second aspect of the invention, the running resistance calculated based on the running state of the vehicle (for example, the wheel speed, engine speed, and throttle opening), the time change amount of the running resistance, and the time change of the absolute value of the wheel speed difference. Based on the amount, it can be accurately determined whether or not the vehicle is turning.

  In the vehicle control apparatus according to the third aspect of the invention, in addition to the configuration of the first or second aspect of the invention, an engine is mounted on the vehicle. The state detection means includes means for detecting the engine speed, means for detecting the degree of request for increase in engine output, and means for detecting the speed of the vehicle. The running resistance calculating means includes means for calculating a predicted acceleration of the vehicle based on the rotational speed and the degree of the increase request, means for calculating the actual acceleration of the vehicle based on the speed of the vehicle, Means for calculating the running resistance based on the difference from the actual acceleration. A vehicle control method according to a ninth aspect has the same configuration as the vehicle control apparatus according to the third aspect.

  According to the third aspect, the torque generated in the engine can be predicted based on the engine speed and the degree of output increase request (for example, throttle opening). Therefore, the driving force acting on the vehicle can be calculated from the generated torque, and the acceleration of the vehicle can be predicted. On the other hand, the actual acceleration of the vehicle can be calculated based on the amount of time change of the vehicle speed. Accordingly, since the difference between the predicted acceleration and the actual acceleration is a decrease due to the travel resistance, the travel resistance can be obtained with high accuracy by calculating the decrease. In addition, since it is not necessary to provide a new component separately to determine whether or not the vehicle is turning, an increase in cost due to an increase in the number of components can be suppressed.

  In the vehicle control apparatus according to the fourth invention, in addition to the configuration of any one of the first to third inventions, the vehicle is equipped with an automatic transmission. The control means controls the automatic transmission based on the determination result by the determination means. A vehicle control method according to a tenth aspect of the invention has the same configuration as the vehicle control apparatus according to the fourth aspect of the invention.

  According to the fourth aspect of the invention, whether or not the vehicle is turning can be determined with high accuracy based on the running resistance and the wheel speed difference. Therefore, by controlling the automatic transmission based on the determination result ( For example, the speed change during turning) and the behavior of the vehicle can be appropriately controlled.

  In the vehicle control apparatus according to the fifth aspect of the invention, in addition to the configuration of any one of the first to fourth aspects of the invention, an electric suspension is mounted on the vehicle. The control means controls the electric suspension based on the determination result by the determination means. A vehicle control method according to an eleventh invention has the same configuration as the vehicle control device according to the fifth invention.

  According to the fifth aspect, since it is possible to accurately determine whether or not the vehicle is turning based on the running resistance and the wheel speed difference, by controlling the electric suspension based on the determination result (for example, , Roll control during turning), and the behavior of the vehicle can be controlled appropriately.

  In the vehicle control apparatus according to the sixth aspect of the invention, in addition to the configuration of any one of the first to fifth aspects, the determination means includes a predetermined number in which the calculated running resistance is smaller than the first value. 4 or less, the time change amount of the running resistance is less than or equal to a predetermined fifth value smaller than the second value, and the time change amount of the absolute value of the wheel speed difference is the third value. When it is equal to or smaller than a predetermined sixth value smaller than the value of, it is determined that the vehicle is traveling straight. A vehicle control method according to a twelfth aspect of the invention has the same configuration as the vehicle control apparatus according to the sixth aspect of the invention.

  According to the sixth invention, the determination as to whether or not the vehicle is going straight ahead is smaller than the fourth value, the fifth value smaller than the second value, and the third value. By using the sixth value, it is possible to suppress frequent switching between the determination result that the vehicle is turning and the determination result that the vehicle is traveling straight according to the behavior of the vehicle. Therefore, it is possible to appropriately control the behavior of the vehicle.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

  As shown in the top view of the vehicle according to the present embodiment in FIG. 1, the vehicle 10 includes a left front wheel 20, a right front wheel 22, a left rear wheel 24, and a right rear wheel 26. And a steering wheel 30. In the present embodiment, the vehicle 10 is described as being a rear wheel drive vehicle, but is not particularly limited to a rear wheel drive vehicle, and may be a front wheel drive vehicle or a four wheel drive vehicle. Be good.

  The vehicle 10 may be a vehicle that uses only the engine as a power source, may be a hybrid vehicle that uses an engine and a rotating electric machine as power sources, or an electric vehicle that uses only the rotating electric machine as a power source. It may be.

  When the driver looks at the steering wheel 30 and rotates the steering wheel 30 clockwise, the left front wheel 20 and the right front wheel 22 are steered to the right with respect to the traveling direction of the vehicle 10. Thereby, the vehicle 10 starts turning in the right direction.

  On the other hand, when the driver looks at the steering wheel 30 and rotates the steering wheel 30 counterclockwise, the left front wheel 20 and the right front wheel 22 are steered to the left with respect to the traveling direction of the vehicle 10. The Thereby, the vehicle 10 starts turning in the left direction.

  As shown in FIG. 2, the vehicle according to the present embodiment includes an ECU (Electronic Control Unit) 100, an automatic transmission 150, an engine 152, a throttle opening sensor 102, an engine speed sensor 104, wheels A speed sensor (L) 106 and a wheel speed sensor (R) 108 are further included.

  ECU 100 includes a CPU (Central Processing Unit) and memory 110. Various information, programs, threshold values, maps, and the like are stored in the memory 110, and data is read or stored by the CPU as necessary.

  The engine 152 is a power source of the vehicle, and may be a gasoline engine or a diesel engine.

  The automatic transmission 150 may be a stepped automatic transmission or a continuously variable automatic transmission that continuously changes the gear ratio.

  The electric suspension 250 independently changes the damping force of the suspension in each wheel 20, 22, 24, 26 by a hydraulic or electric actuator based on a control signal from the ECU 100, for example. In the electric suspension 250, the damping force of the suspension in each of the wheels 20, 22, 24, and 26 is appropriately controlled by the ECU 100 so that the roll amount of the vehicle body while the vehicle is turning is reduced.

  The throttle opening sensor 102 detects the opening of the throttle valve of the electronic throttle 154 of the engine 152 (hereinafter simply referred to as the throttle opening). The throttle opening sensor 102 transmits a signal (throttle opening signal) indicating the detected throttle opening to the ECU 100. Instead of the throttle opening sensor 102, an accelerator position sensor that detects the depression amount of the accelerator pedal may be used.

  The engine speed sensor 104 detects the speed of the output shaft of the engine 152 (hereinafter referred to as engine speed). The engine speed sensor 104 transmits a signal (engine speed signal) indicating the detected engine speed to the ECU 100.

  The wheel speed sensor (L) 106 detects the rotational speed of the left front wheel 20. The wheel speed sensor (L) 106 transmits a signal (wheel speed signal (1)) indicating the detected rotational speed of the wheel 20 to the ECU 100. The wheel speed sensor (L) 106 preferably detects the rotational speed of the wheel 20 that is a driven wheel, but may detect the rotational speed of the left rear wheel 24 instead of the wheel 20. Good.

  In the present embodiment, ECU 100 will be described as receiving the rotational speed of wheel 20 or 24 from wheel speed sensor (L) 106 and using the received rotational speed for subsequent processing. It is also possible to calculate an average value of the rotational speeds detected in 24 and use the calculated average value for the subsequent calculation processing.

  The wheel speed sensor (R) 108 detects the rotational speed of the right front wheel 22. The wheel speed sensor (R) 108 transmits a signal (wheel speed signal (2)) indicating the detected rotational speed of the wheel 22 to the ECU 100. The wheel speed sensor (R) 108 preferably detects the rotational speed of the wheel 22 which is a driven wheel, but may detect the rotational speed of the right rear wheel 26 instead of the wheel 22. Good.

  In the present embodiment, ECU 100 will be described as receiving the rotational speed of wheel 22 or 26 from wheel speed sensor (R) 108 and using the received rotational speed for subsequent processing. It is also possible to calculate the average value of the detected rotational speeds at 26 and use the calculated average value for the subsequent arithmetic processing.

  In the vehicle having the above configuration, it is necessary to accurately determine whether or not the vehicle is turning when controlling the behavior of the vehicle. However, in order to determine whether or not the vehicle is turning, it is necessary to separately provide components such as navigation and a steering angle sensor, for example. Therefore, the cost may increase.

  Therefore, according to the present invention, the ECU 100 calculates the running resistance based on the running state of the vehicle related to the running resistance, calculates the time change amount of the running resistance based on the calculated running resistance, and the left and right wheels. By calculating the time change amount of the absolute value of the wheel speed difference between 20 and 22, the running resistance is not less than a predetermined value A, and the time change amount of the running resistance is not less than a predetermined value B. And when the time change amount of the absolute value of the wheel speed difference between the left and right wheels 20 and 22 is not less than a predetermined value C, it is characterized in that it is determined that the vehicle is turning.

  In the present embodiment, “running resistance” refers to a force acting in the direction opposite to the traveling direction when the vehicle travels. The running resistance includes, for example, air resistance, gradient resistance, rolling resistance of tires at the wheels 20, 22, 24, and 26, and bearing portions provided in the vehicle 10 when the wheels 20, 22, 24, and 26 are rotated. Including frictional resistance.

  ECU 100 calculates the predicted acceleration of the vehicle based on the engine speed and the throttle opening. Moreover, ECU100 calculates the actual acceleration of a vehicle based on the wheel speed in any one of the wheels 20, 22, 24, 26 which shows the speed of a vehicle. Furthermore, the ECU 100 calculates the running resistance based on the difference between the predicted acceleration and the actual acceleration. The wheel speed may be an average value of at least two rotation speeds of the wheels 20, 22, 24, 26, and may be an average value of the rotation speeds of the driven wheels, for example. Alternatively, the vehicle speed may be calculated based on the output shaft rotation speed of the automatic transmission 150, and the actual acceleration of the vehicle may be calculated based on the calculated vehicle speed.

  Further, ECU 100 controls the vehicle based on the determination result of whether or not the vehicle is turning. In the present embodiment, ECU 100 controls automatic transmission 150 or electric suspension 250 based on the determination result of whether or not the vehicle is turning.

  FIG. 3 shows a functional block diagram of ECU 100 that is the vehicle control apparatus according to the present embodiment.

  ECU 100 includes a travel resistance calculation unit 200, a travel resistance change amount calculation unit 202, a wheel speed difference change amount calculation unit 204, a turning determination unit 206, and a vehicle control unit 208.

  The travel resistance calculation unit 200 includes a throttle opening signal from the throttle opening sensor 102, an engine speed signal received from the engine speed sensor 104, and a wheel speed signal (1) from the wheel speed sensor (L) 106. The running resistance is calculated based on the wheel speed signal (2) from the wheel speed sensor (R) 108.

  Specifically, the running resistance calculation unit 200 calculates the predicted acceleration of the vehicle based on the throttle opening, the engine speed, and a map showing the relationship between the engine speed, the throttle opening, and the engine torque shown in FIG. .

  For example, when the throttle opening is A% and the engine speed is NE (0), the running resistance calculating unit 200 is configured to generate an engine torque Te () corresponding to the engine speed NE (0) shown by a solid line in FIG. 0), the engine torque expressed by the engine 152 is specified based on the engine speed and the throttle opening. The running resistance calculation unit 200 calculates a vehicle acceleration that is predicted based on the specified engine torque, that is, a predicted acceleration.

  The running resistance calculation unit 400 calculates the actual acceleration of the vehicle based on at least one of the wheel speed signal (1) and the wheel speed signal (2). The running resistance calculation unit 400 may calculate the actual acceleration based on the wheel speed of one of the wheels 20 and 22, or the average value of the wheel speed of the wheel 20 and the wheel speed of the wheel 22 may be calculated. Based on this, the actual acceleration may be calculated.

  The running resistance calculation unit 400 calculates the running resistance based on the difference between the predicted acceleration and the actual acceleration. The running resistance calculation unit 400 calculates the actual running resistance based on the difference between the predicted acceleration and the actual acceleration and the vehicle weight, and uses the calculated actual running resistance as “running resistance” for the subsequent calculation processing. Alternatively, the difference between the predicted acceleration and the actual acceleration may be used as a “running resistance” for subsequent calculation processing. The running resistance calculation unit 400 stores the calculated running resistance in the memory 110 and uses it for the calculation processing in the next running resistance change calculation unit 202.

  The travel resistance change amount calculation unit 202 calculates a time change amount of the travel resistance based on the calculated travel resistance. Specifically, the travel resistance change amount calculation unit 202 may calculate a differential value of the calculated travel resistance, or the travel resistance (1) calculated by the travel resistance calculation unit 200 during the previous calculation. And the difference between the running resistance (2) calculated by the running resistance calculation unit 200 at the time of the current calculation may be divided by the calculation cycle time.

  The wheel speed difference change amount calculation unit 204 calculates the time change amount of the absolute value of the left and right wheel speed difference based on the wheel speed signal (1) and the wheel speed signal (2). Specifically, the wheel speed difference change amount calculation unit 204 calculates the absolute value of the wheel speed difference between the wheels 20 and 22. The wheel speed difference change amount calculation unit 204 subtracts the absolute value of the wheel speed difference calculated at the current calculation from the absolute value of the wheel speed difference calculated at the previous calculation, and calculates the subtracted value as the calculation cycle time. The time change amount of the absolute value of the left and right wheel speed difference is calculated by dividing by. The wheel speed difference change amount calculation unit 204 stores the calculated time change amount of the absolute value of the left and right wheel speed difference in the memory 110 and uses it for the calculation process in the next wheel speed difference change amount calculation unit 204.

  The turning determination unit 206 determines whether or not the vehicle is turning based on the running resistance, the time change amount of the running resistance, and the time change amount of the absolute value of the left and right wheel speed difference. Further, the turning determination unit 206 determines whether or not the vehicle is traveling straight based on the travel resistance, the temporal change amount of the travel resistance, and the temporal change amount of the absolute value of the left and right wheel speed difference.

  Specifically, the turning determination unit 206 is configured such that the running resistance is equal to or greater than a predetermined value A, the time change amount of the running resistance is equal to or greater than a predetermined value B, and the left and right wheel speed difference When the time change amount of the absolute value of the vehicle is equal to or greater than a predetermined value C, it is determined that the vehicle is turning. The predetermined values A, B, and C are values that are suitable for experiments and the like, and are not particularly limited.

  Further, the turning determination unit 206 is configured such that the running resistance is equal to or less than a predetermined value D, the time change amount of the running resistance is equal to or less than a predetermined value E, and an absolute value of a difference between the left and right wheel speeds. When the amount of time change is equal to or less than a predetermined value F, it is determined that the vehicle is traveling straight. The predetermined value D is not particularly limited as long as it is smaller than the predetermined value A. Further, the predetermined value E is not particularly limited as long as it is smaller than the predetermined value B. Further, the predetermined value F is not particularly limited as long as it is smaller than the predetermined value C. Predetermined values D, E, and F are frequently interchanged between the determination that the vehicle is turning and the determination that the vehicle is traveling straight in relation to predetermined values A, B, and C. Set to not.

  The turning determination unit 206 turns on the turning determination flag when it determines that the vehicle is turning, and turns off the turning determination flag when it is determined that the vehicle is traveling straight. Note that the turning determination flag is initially off.

  The vehicle control unit 208 controls the vehicle based on the determination result in the turning determination unit 206. For example, the vehicle control unit 208 controls the vehicle based on the state of the turning determination flag. In the present embodiment, vehicle control unit 208 controls at least one of automatic transmission 150 and electric suspension 250 based on the determination result in turning determination unit 206.

  In the present embodiment, for example, when it is determined that the vehicle is turning, the vehicle control unit 208 causes the automatic transmission 150 to limit the shift to the upshift side and / or the downshift side. Control. In addition, the vehicle control unit 208 controls the automatic transmission 150 so as to release the shift restriction when it is determined that the vehicle is traveling straight ahead.

  Alternatively, for example, when it is determined that the vehicle is turning, the vehicle control unit 208 controls the suspension damping force at the wheels 20, 22, 24, and 26 so that the roll amount of the vehicle decreases in the electric suspension 250. To do. Further, the vehicle control unit 208 controls the damping force of the suspensions of the wheels 20, 22, 24, and 26 to return to the initial value when it is determined that the vehicle is traveling straight. In addition, since the specific control aspect of an electric suspension is a known technique, the detailed description is not performed.

  The vehicle control unit 208 is not particularly limited to the automatic transmission 150 and the electric suspension 250 as long as the vehicle control unit 208 controls devices having different control modes when the vehicle is turning and when traveling straight. For example, the vehicle control unit 208 may control the seat belt unit so as to increase the holding force of the seat belt when the vehicle turns and return the holding force of the seat belt to the initial value when the vehicle goes straight. When turning, the headlight irradiation direction may be changed to the turning direction of the vehicle, and the headlight unit may be controlled to return the headlight irradiation direction to the traveling direction when the vehicle goes straight.

  In the present embodiment, the running resistance calculation unit 200, the running resistance change amount calculation unit 202, the wheel speed difference change amount calculation unit 204, the turning determination unit 206, and the vehicle control unit 208 are all ECU 100. The CPU is described as functioning as software realized by executing a program stored in the memory 110, but may be realized by hardware. Such a program is recorded on a storage medium and mounted on the vehicle.

  Referring to FIG. 5, a control structure of a program executed by ECU 100 that is the vehicle control apparatus according to the present embodiment will be described.

  In step (hereinafter, step is referred to as S) 100, ECU 100 determines whether or not the vehicle is turning. Specifically, ECU 100 determines that the vehicle is turning when the turn determination flag is on, and determines that the vehicle is not turning when the turn determination flag is off. If it is determined that the vehicle is turning (YES in S100), the process proceeds to S102. If not (NO in S100), the process proceeds to S110.

  In step S102, the ECU 100 determines whether or not the running resistance is equal to or less than a predetermined value D and the time variation amount of the running resistance is equal to or less than a predetermined value E. If the running resistance is equal to or less than a predetermined value D and the amount of time change of the running resistance is equal to or less than a predetermined value E (YES in S102), the process proceeds to S104. If not (NO in S102), the process proceeds to S108.

  In S104, ECU 100 determines whether or not the amount of time change in the absolute value of the difference between the left and right wheel speeds is equal to or less than a predetermined value F. If the time change amount of the absolute value of the difference between the left and right wheel speeds is equal to or smaller than a predetermined value F (YES in S104), the process proceeds to S106. If not (NO in S104), the process proceeds to S108.

  In S106, ECU 100 determines that the vehicle is traveling straight ahead. The ECU 100 changes the turning determination flag from on to off. In S108, ECU 100 determines that the vehicle is continuously turning. That is, the ECU 100 maintains the turning determination flag on.

  In S110, ECU 100 determines whether or not the running resistance is equal to or greater than a predetermined value A and the amount of time change of the running resistance is equal to or greater than a predetermined value B. If the running resistance is greater than or equal to a predetermined value A and the amount of time change in running resistance is greater than or equal to a predetermined value B (YES in S110), the process proceeds to S112. Otherwise (NO in S110), this process ends.

  In S112, ECU 100 determines whether or not the amount of time change of the absolute value of the left and right wheel speed difference is equal to or greater than a predetermined value C. If the amount of time change in the absolute value of the difference between the left and right wheel speeds is equal to or greater than a predetermined value C (YES in S112), the process proceeds to S114. Otherwise (NO in S112), this process ends.

  In S114, ECU 100 determines that the vehicle is turning. That is, the ECU 100 changes the turning determination flag from off to on. In S116, ECU 100 determines that the vehicle continues straight ahead. That is, ECU 100 maintains the turning determination flag in the off state.

  In S118, ECU 100 controls at least one of automatic transmission 150 and electric suspension 250 in accordance with the state of the turning determination flag.

  The operation of ECU 100 as the vehicle control apparatus according to the present embodiment based on the structure and flowchart as described above will be described with reference to FIG.

  For example, assume that the vehicle starts to turn right when the vehicle is moving straight ahead while accelerating gently. As shown in FIG. 6, the period during which the driver performs an operation includes a steering right turn-up period from time T (2), a steering holding period from time T (2) to time T (3), and time. A steering return period from T (3) to time T (4) and a partial period after time T (5) are included.

  Since the wheel speed difference is the same during straight traveling of the vehicle, the amount of time change of the absolute value of the wheel speed difference is zero. Further, when the vehicle is accelerated, the running resistance is R (0) because it receives running resistance such as air resistance, gradient resistance, tire rolling resistance, and friction resistance of the bearing portion.

  In such a case, when a driver who rides rotates the steering wheel 30 in the right turning direction, the left front wheel 20 and the right front wheel 22 are steered to the right with respect to the straight traveling direction of the vehicle. When the wheels 20 and 22 are steered, the vehicle starts to turn as the tires of the wheels 20 and 22 slip in the direction in which the wheels 20 and 22 are steered. During a right turn, the rotation speed of the right front wheel 22 located on the turn center side is smaller than the rotation speed of the left front wheel 20, so that the steering amount of the steering wheel 30 in the right turn direction increases. The difference between the left and right wheel speeds will increase.

  When the tire slips, the running resistance increases from R (0). As the running resistance increases, the amount of time change in running resistance also increases.

  Even when the turning determination flag is OFF at time T (0) (NO in S100), the running resistance is a predetermined value even if the amount of time change in the running resistance is equal to or greater than a predetermined value B. If it is smaller than A (NO in S102), it is determined that the vehicle is continuing straight (S116). Therefore, the automatic transmission 150 or the electric suspension 250 is controlled in response to the vehicle traveling straight (S118).

  At time T (1), the turning determination flag is off (NO in S100), the amount of change in travel resistance with time is greater than or equal to a predetermined value B, and the travel resistance is predetermined. When the value is greater than or equal to value A (YES in S110), if the amount of time change in the absolute value of the left and right wheel speed difference is greater than or equal to a predetermined value C (YES in S112), the vehicle is turning. Is determined (S114). At this time, the turning determination flag is turned on. Therefore, the automatic transmission 150 or the electric suspension 250 is controlled in response to the vehicle turning (S118).

  When the driver holds the steering amount of the steering wheel 30 in the right turn direction during the period from time T (2) to time T (3) (steering holding period), the running resistance becomes a substantially constant state, The time change amount of the running resistance decreases as the running resistance increases gradually. The difference between the left and right wheel speeds is substantially constant because the steering amount is maintained.

  At this time, the turning determination flag is on (YES in S100), and the running resistance of the vehicle is larger than a predetermined value D, or the time change amount of the running resistance is from a predetermined value E. (NO in S102), it is determined that the vehicle is continuously turning (S108). Therefore, the automatic transmission 150 or the electric suspension 250 is controlled in response to the vehicle turning (S118).

  After the time T (3), when the driver starts to return the steering wheel 30, the slip of the wheels 20 and 22 is eliminated, so that the running resistance starts to decrease. Therefore, the amount of time change in running resistance decreases to the negative side. Further, since the steering amount of the vehicle decreases, the wheel speed difference also starts to decrease. Therefore, the amount of time change of the absolute value of the wheel speed difference decreases to the negative side.

  At time T (4), the running resistance is less than or equal to a predetermined value D, and the amount of change in the running resistance with time is less than or equal to a predetermined value E (YES in S102). If the amount of time change in the absolute value of the wheel speed difference is equal to or smaller than a predetermined value F (YES in S104), it is determined that the vehicle is traveling straight (S106). At this time, the turning determination flag is turned off. Therefore, the automatic transmission 150 or the electric suspension 250 is controlled in response to the vehicle traveling straight (S118).

  When the driver returns the steering wheel 30 to the steering amount corresponding to the straight traveling of the vehicle at time T (5), the turning determination flag is off (NO in S100), and the running resistance is a predetermined value. R (0) is lower than A (NO in S110). Therefore, since it is determined that the vehicle is continuously traveling straight (S116), the automatic transmission 150 or the electric suspension 250 is controlled in response to the vehicle traveling straight (S118).

  Note that the same determination and control as when turning right is performed when the vehicle turns left. Therefore, detailed description thereof will not be repeated. Whether the vehicle is turning right or left may be determined based on, for example, the sign of the difference between the left and right wheel speeds, or, for example, the rotational speed of the right wheel may be If it is greater than the rotational speed, it may be determined that the vehicle is turning left, and if the rotational speed of the left wheel is greater than that of the right side, it may be determined that the vehicle is turning right.

  As described above, according to the vehicle control apparatus of the present embodiment, the running resistance is greater than or equal to the predetermined value A, and the time change amount of the running resistance is greater than or equal to the predetermined value B. And when the amount of time change of the absolute value of the wheel speed difference is not less than a predetermined value C, the running resistance tends to increase, and the difference in rotational speed between the left and right wheel speeds is increasing. It can be determined that the vehicle is turning. Therefore, for example, compared with the case where it is determined whether or not the vehicle is turning only by the wheel speed, it is possible to suppress the determination accuracy from deteriorating even when the wheel slips. That is, it can be accurately determined whether or not the vehicle is turning. Therefore, the behavior of the vehicle can be controlled with high accuracy by controlling the vehicle based on the determination result of whether or not the vehicle is turning. In addition, since the running resistance can be calculated based on the difference between the actual acceleration and the predicted acceleration, it is not necessary to provide a new component in order to determine whether or not the vehicle is turning. As a result, an increase in cost due to an increase in the number of parts can be suppressed. Therefore, it is possible to provide a vehicle control device and a control method for determining whether or not the vehicle is turning while controlling an increase in cost and controlling the behavior of the vehicle with high accuracy.

  Further, it is possible to predict the torque generated in the engine based on the engine speed and the degree of request for increase in output (for example, throttle opening). Therefore, the driving force acting on the vehicle can be calculated from the generated torque, and the acceleration of the vehicle can be predicted. On the other hand, the actual acceleration of the vehicle can be calculated based on the amount of time change of the vehicle speed. Accordingly, since the difference between the predicted acceleration and the actual acceleration is a decrease due to the travel resistance, the travel resistance can be obtained with high accuracy by calculating the decrease.

  Further, by controlling the automatic transmission or the electric suspension based on the determination result of whether or not the vehicle is turning (for example, shift limit control during turning or roll amount reduction control), the behavior of the vehicle is appropriately adjusted. Can be controlled.

  Then, whether or not the vehicle is going straight ahead is determined by a predetermined value D smaller than a predetermined value A, a predetermined value E smaller than a predetermined value B, and a predetermined value. By using a predetermined value F that is smaller than the value C, it is possible to suppress frequent switching between the determination result that the vehicle is turning and the determination result that the vehicle is traveling straight according to the behavior of the vehicle. Therefore, it is possible to appropriately control the behavior of the vehicle.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a top view of the vehicle in this Embodiment. It is a schematic block diagram of the vehicle in this Embodiment. It is a functional block diagram of ECU which is a control device of vehicles concerning this embodiment. It is a figure which shows the relationship between an engine torque, rotation speed, and throttle opening. It is a flowchart which shows the control structure of the program performed with ECU which is the control apparatus of the vehicle which concerns on this Embodiment. It is a timing chart which shows operation | movement of ECU which is a control apparatus of the vehicle which concerns on this Embodiment.

Explanation of symbols

  10 Vehicle, 20, 22, 24, 26 Wheel, 30 Steering wheel, 100 ECU, 102 Throttle opening sensor, 104 Engine speed sensor, 110 Memory, 150 Automatic transmission, 152 Engine, 154 Electronic throttle, 200 Running resistance calculation Unit, 202 travel resistance change amount calculation unit, 204 wheel speed difference change amount calculation unit, 206 turning determination unit, 208 vehicle control unit, 250 electric suspension.

Claims (12)

A vehicle control device, wherein the vehicle has left and right wheels,
Travel resistance calculating means for calculating a travel resistance acting in the direction opposite to the traveling direction when the vehicle travels;
Means for calculating a time change amount of the running resistance based on the calculated running resistance;
Means for calculating the amount of time change of the absolute value of the wheel speed difference between the left and right wheels based on the wheel speeds of the left and right wheels;
The travel resistance is greater than or equal to a predetermined first value, the amount of time variation of the travel resistance is greater than or equal to a predetermined second value, and the absolute value of the wheel speed difference varies with time. Determination means for determining that the vehicle is turning when the amount is equal to or greater than a predetermined third value;
And a control unit for controlling the vehicle based on a determination result by the determination unit. The control device further includes a state detecting means for detecting a traveling state of the vehicle related to the traveling resistance,
The vehicle control device according to claim 1, wherein the running resistance calculating unit calculates the running resistance based on the detected running state. The vehicle is equipped with an engine,
The state detection means includes
Means for detecting the rotational speed of the engine;
Means for detecting the degree of demand for an increase in output of the engine;
Means for detecting the speed of the vehicle,
The running resistance calculation means includes
Means for calculating a predicted acceleration of the vehicle based on the rotational speed and the degree of the increase request;
Means for calculating an actual acceleration of the vehicle based on the speed of the vehicle;
The vehicle control device according to claim 1, further comprising means for calculating the running resistance based on a difference between the predicted acceleration and the actual acceleration. The vehicle is equipped with an automatic transmission,
The vehicle control device according to claim 1, wherein the control unit controls the automatic transmission based on a determination result by the determination unit. The vehicle is equipped with an electric suspension,
The vehicle control device according to claim 1, wherein the control unit controls the electric suspension based on a determination result by the determination unit.   The determination unit is configured in advance so that the calculated running resistance is equal to or less than a predetermined fourth value smaller than the first value, and the time change amount of the running resistance is smaller than the second value. When the vehicle is less than or equal to a predetermined fifth value and the time change amount of the absolute value of the wheel speed difference is less than or equal to a predetermined sixth value smaller than the third value, the vehicle The vehicle control device according to claim 1, wherein it is determined that the vehicle is traveling straight. A vehicle control method, wherein the vehicle has left and right wheels,
A running resistance calculating step for calculating a running resistance acting in a direction opposite to the traveling direction when the vehicle runs;
Calculating a time change amount of the running resistance based on the calculated running resistance;
Calculating a time change amount of an absolute value of a wheel speed difference between the left and right wheels based on the left and right wheel speeds;
The travel resistance is greater than or equal to a predetermined first value, the amount of time variation of the travel resistance is greater than or equal to a predetermined second value, and the time variation of the absolute value of the wheel speed difference A determination step of determining that the vehicle is turning when the amount is equal to or greater than a predetermined third value;
And a control step of controlling the vehicle based on a determination result in the determination step. The control method further includes a state detection step of detecting a traveling state of the vehicle related to the traveling resistance,
The vehicle control method according to claim 7, wherein the travel resistance calculation step calculates the travel resistance based on the detected travel state. The vehicle is equipped with an engine,
The state detection step includes
Detecting the rotational speed of the engine;
Detecting the degree of increase request of the engine output;
Detecting the speed of the vehicle,
The running resistance calculation step includes:
Calculating a predicted acceleration of the vehicle based on the rotational speed and the degree of the increase request;
Calculating the actual acceleration of the vehicle based on the speed of the vehicle;
The vehicle control method according to claim 7, further comprising: calculating the running resistance based on a difference between the predicted acceleration and the actual acceleration. The vehicle is equipped with an automatic transmission,
The vehicle control method according to claim 7, wherein the control step controls the automatic transmission based on a determination result in the determination step. The vehicle is equipped with an electric suspension,
The vehicle control method according to claim 7, wherein the control step controls the electric suspension based on a determination result in the determination step.   In the determination step, the calculated running resistance is equal to or smaller than a predetermined fourth value smaller than the first value, and the time change amount of the running resistance is smaller than the second value in advance. When the vehicle is less than or equal to a predetermined fifth value and the time change amount of the absolute value of the wheel speed difference is less than or equal to a predetermined sixth value smaller than the third value, the vehicle The vehicle control method according to claim 7, wherein the vehicle is determined to be traveling straight.

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