JP5141314B2 - Vehicle travel control device - Google Patents

Description

  The present invention relates to a vehicle travel control device, and in particular, is provided in a vehicle on which an internal combustion engine and a continuously variable transmission that transmits the output of the internal combustion engine to a drive shaft are mounted, and is a target value for the rotational speed of the internal combustion engine. The present invention relates to a vehicle travel control device that controls an internal combustion engine and a continuously variable transmission to achieve a target rotational speed.

  In a vehicle equipped with an internal combustion engine and a continuously variable transmission that transmits the output of the internal combustion engine to a drive shaft, the internal combustion engine and the continuously variable transmission are realized so as to achieve a target rotational speed that is a target value of the rotational speed of the internal combustion engine. When the aircraft is controlled, the driver may not feel an appropriate acceleration feeling during acceleration. The feeling of acceleration felt by the driver differs depending not only on the actual vehicle speed change but also on the engine sound and the like. For this reason, depending on the control mode of the internal combustion engine and the continuously variable transmission, an appropriate feeling of acceleration may not be obtained even though the vehicle is accelerating.

  In Patent Document 1, in a vehicle in which the increase in the speed of the vehicle and the increase in the engine rotation speed of the internal combustion engine are not proportionally linked during acceleration, the internal combustion engine is An engine sound emphasizing device including engine sound adjusting means for increasing engine sound is disclosed. According to this engine sound emphasizing device, the driver of the vehicle can obtain an acceleration feeling even when the increase in the vehicle speed and the increase in the engine rotation speed of the internal combustion engine are not proportionally linked.

JP 2006-83818 A

  When the internal combustion engine and the continuously variable transmission are controlled so as to achieve the target rotational speed of the internal combustion engine, there has not been sufficient investigation in the past to give the driver an appropriate acceleration feeling during acceleration. For example, when the engine sound of the internal combustion engine is increased based on the increase in the vehicle speed as in the above-mentioned Patent Document 1, when the acceleration state continues for a certain period of time, the change in the engine sound is felt monotonously, and the driver May not be able to get a proper acceleration feeling.

  In a vehicle equipped with an internal combustion engine and a continuously variable transmission that transmits the output of the internal combustion engine to a drive shaft, the internal combustion engine and the continuously variable transmission are realized so as to achieve a target rotational speed that is a target value of the rotational speed of the internal combustion engine. When the aircraft is controlled, it is desired to give an appropriate feeling of acceleration to the driver during acceleration.

  An object of the present invention is provided in a vehicle on which an internal combustion engine and a continuously variable transmission that transmits the output of the internal combustion engine to a drive shaft are mounted, and the internal combustion engine and the continuously variable engine so as to achieve a target rotational speed of the internal combustion engine. An object of the present invention is to provide a vehicle travel control device that controls a transmission and that can give an appropriate feeling of acceleration to a driver during acceleration.

The vehicle travel control device of the present invention is provided in a vehicle on which an internal combustion engine and a continuously variable transmission that transmits the output of the internal combustion engine to a drive shaft are mounted, and is a target that is a target value of the rotational speed of the internal combustion engine. A vehicle travel control device that controls the internal combustion engine and the continuously variable transmission so as to realize a rotational speed, the setting means for setting the target rotational speed based on a vehicle speed, and a driver's demand for acceleration an acceleration request detecting means for detecting is a continuation determination means for determining whether the acceleration request is detected continuously a predetermined a predetermined time by the acceleration request detecting means, said vehicle acceleration state and a state determining means for determining whether or not, the setting means, continues the vehicle by the state determining means is determined to be in the acceleration state, and by the continuation determining means and the acceleration request is the predetermined time or more The target rotational speed is determined based on a characteristic line determined so that the increase amount of the vehicle speed and the increase amount of the sound pressure of the internal combustion engine are proportional to each other. And when it is determined by the continuation determination means that the acceleration request is continuously detected for the predetermined time or more, it is determined that the vehicle is in an acceleration state, and the acceleration request is determined for the predetermined time. The target rotational speed is set so as to increase the amount of increase in the sound pressure of the internal combustion engine relative to the amount of increase in the vehicle speed as compared with the case where it is not determined that the detection is continuously performed, and the acceleration When the duration of the request is long, the target rotational speed is set so as to increase the amount of increase in the sound pressure of the internal combustion engine relative to the amount of increase in the vehicle speed, compared to the case where the duration is short. Features.

  In the vehicle travel control device of the present invention, the setting means increases the target rotational speed as the vehicle speed increases, and the rotation with a small increase in the sound pressure with respect to the increase in the rotational speed is performed. In the number region, the increase amount of the target rotation number with respect to the increase amount of the vehicle speed is increased compared with the rotation number region in which the increase amount of the sound pressure with respect to the increase amount of the rotation number is large. The increase amount of the sound pressure is proportional to the increase amount of the vehicle speed.

  The vehicle travel control apparatus according to the present invention is characterized in that the target rotational speed is realized by changing the rotational speed by shift control of the continuously variable transmission.

  According to the present invention, in a vehicle equipped with an internal combustion engine and a continuously variable transmission that transmits the output of the internal combustion engine to a drive shaft, the internal combustion engine and the continuously variable transmission are realized so as to achieve a target rotational speed of the internal combustion engine. When it is determined that the driver's acceleration request is continuously detected for a predetermined time or longer, the acceleration request is determined to be continuously detected for the predetermined time or longer. The target rotational speed is set so as to increase the increase amount of the sound pressure of the internal combustion engine with respect to the increase amount of the vehicle speed as compared with the case where it is not performed. As a result, when it is estimated that acceleration over a certain level continues for a long time and the driver is seeking further acceleration, the increase in engine sound pressure is increased to improve the feeling of acceleration. Can give an appropriate feeling of acceleration.

  Hereinafter, an embodiment of a vehicle travel control device of the present invention will be described in detail with reference to the drawings.

(First embodiment)
The first embodiment will be described with reference to FIGS. 1 to 13. The present embodiment is provided in a vehicle on which an internal combustion engine and a continuously variable transmission that transmits the output of the internal combustion engine to a drive shaft are mounted, and achieves a target rotational speed that is a target value of the rotational speed of the internal combustion engine. In particular, the present invention relates to a vehicle travel control device that controls an internal combustion engine and a continuously variable transmission.

  In the present embodiment, in a vehicle equipped with an engine (internal combustion engine) and a continuously variable transmission that transmits the output of the engine to a drive shaft, a target engine rotation speed that is a target value of the engine rotation speed (number of rotations). The engine and the continuously variable transmission are controlled to achieve (target rotational speed). At the time of acceleration, the acceleration linear feeling is improved by controlling the target engine speed according to the sound pressure characteristic of the engine.

  More specifically, based on the control that fluctuates the target engine speed in proportion to the vehicle speed, the gear ratio is set to a lower speed in a region where the increase in engine sound pressure with respect to the increase in engine speed is low. To do. That is, in the region of the engine rotation speed where the increase in engine sound pressure is moderate and the driver does not feel acceleration feeling, the increase in engine rotation speed is promoted. Thereby, the rising speed of the engine sound pressure is increased, and it is suppressed that the driver and the passenger feel a stagnation feeling of the engine rotation increase during acceleration.

  On the other hand, in a region where the increase in engine sound pressure is high relative to the increase in engine rotation speed, the gear ratio is set to a higher speed side. That is, in the engine rotation speed region where the engine sound pressure increases rapidly and the driver feels that the engine sound is noisy, the increase in the engine rotation speed is moderated. Thereby, the rising speed of the engine sound pressure can be suppressed and noise can be reduced.

  Here, by controlling the target engine speed according to the characteristics of the engine sound pressure and making the increase amount of the engine sound pressure proportional to the increase amount of the vehicle speed, although the acceleration linear feeling is improved, When the engine sound pressure increases in proportion to the increase, the engine sound pressure changes monotonously while the acceleration continues.

  In this embodiment, when acceleration over a certain level continues for a long time, the driver determines that further acceleration is desired, and adds a correction amount calculated based on the engine sound pressure characteristics to the target engine rotation speed. The acceleration feeling is improved by increasing the engine sound pressure.

The configuration of the present embodiment is premised on the following configurations (1) to (5).
(1) Internal combustion engine (2) Continuously variable transmission (CVT, continuously variable transmission (continuously variable transmission mechanism) provided in HV vehicles)
(3) Driving force control device (in particular, a control structure in which a target driving force is determined with respect to an accelerator input)
(4) Accelerator pedal (5) Accelerator pedal displacement sensor

  FIG. 1 is a block diagram according to the driving force control of the present embodiment.

  In FIG. 1, reference numeral 1 denotes an engine (internal combustion engine). The output torque of the engine 1 is transmitted to the continuously variable transmission 2. The continuously variable transmission 2 controls the gear ratio steplessly (continuously), and transmits the output of the engine 1 to a drive shaft (not shown). An output shaft (not shown) of the engine 1 is configured to be connectable to an input shaft (not shown) of the continuously variable transmission 2, and the input rotational speed (input shaft rotational speed) of the continuously variable transmission 2 is This corresponds to the engine rotation speed (output shaft rotation speed) which is the rotation speed of the engine 1. Note that the vehicle travel control device according to the present embodiment is capable of controlling the input rotational speed (engine rotational speed) of the continuously variable transmission 2 according to the vehicle speed, such as a continuously variable transmission (continuously variable transmission mechanism) of a CVT or HV vehicle. The present invention can be applied to various continuously variable transmissions in which a target value is set.

  A vehicle (not shown) on which the engine 1 and the continuously variable transmission 2 are mounted is provided with a vehicle travel control device 100 that controls the vehicle. The vehicle travel control device 100 controls the engine 1 and the continuously variable transmission 2 so as to realize a target engine rotation speed that is a target value of the engine rotation speed. More specifically, the vehicle travel control apparatus 100 calculates a target engine rotation speed based on the target driving force, and sets the target input rotation speed of the continuously variable transmission 2 so as to realize the calculated target engine rotation speed. Set. The vehicle travel control device 100 executes operation control of the engine 1 based on the target engine rotational speed and the target engine torque set corresponding to the target engine rotational speed, and the continuously variable transmission 2 of the continuously variable transmission 2 based on the target input rotational speed. Shift control is executed.

  The vehicle travel control device 100 includes a target driving force calculation unit 10, a control amount calculation unit 20, and a control unit 30. The vehicle travel control device 100 is configured by a well-known microcomputer and includes a CPU, a RAM, a ROM, an input port, an output port, and a common bus (not shown). The vehicle travel control apparatus 100 according to the present embodiment has a state determination unit that determines whether or not the vehicle is in an acceleration state, an acceleration request detection unit that detects a driver's acceleration request, and an acceleration request detection unit that issues an acceleration request. It has a function as continuation determination means for determining whether or not the detection is continued for a predetermined time or more.

  The target driving force calculation unit 10 calculates a target driving force Ftgt based on the accelerator opening (accelerator operation amount) accp and the vehicle speed spd. Accelerator opening degree detection means 3 and vehicle speed detection means 4 are connected to the target driving force calculation unit 10. The accelerator opening detecting means 3 detects an accelerator operation amount that is a driver's operation amount for an accelerator (not shown). The accelerator is not limited to a so-called accelerator pedal, but an operating device that instructs the vehicle on the acceleration (driving force) required by the driver. Based on the accelerator operation amount, the magnitude of the driver's acceleration request is detected (estimated). The accelerator opening degree detecting means 3 detects an accelerator opening degree accp [%] in which the accelerator opening degree when the accelerator is fully opened is 100%, and outputs a signal corresponding to the detection result to the target driving force calculation unit 10. To do. The target driving force calculation unit 10 detects the accelerator opening degree accp based on the signal acquired from the accelerator opening degree detection means 3.

  The vehicle speed detection means 4 detects a vehicle speed spd that is the speed of the vehicle. The vehicle speed detection means 4 detects, for example, the rotation speed of the output shaft of the continuously variable transmission 2 that is proportional to the vehicle speed spd, and outputs a signal corresponding to the detection result to the target driving force calculation unit 10. The target driving force calculation unit 10 detects the vehicle speed spd based on the signal acquired from the vehicle speed detection means 4.

  The target driving force calculation unit 10 calculates the target driving force Ftgt with reference to the map shown in FIG. 2 based on the detected accelerator opening degree accp and the vehicle speed spd. In FIG. 2, the horizontal axis represents the vehicle speed spd, and the vertical axis represents the driving force force. Symbols accp1, accp2, and accp3 are curves showing the relationship between the vehicle speed spd and the target driving force Ftgt according to the accelerator opening degree accp. The accelerator opening degree accp has a large value in the order of accp1 to accp3. As shown in FIG. 2, the target driving force Ftgt is calculated as a larger value as the accelerator opening degree accp becomes larger with respect to a predetermined vehicle speed spd. The target driving force calculation unit 10 outputs the calculated target driving force Ftgt and the vehicle speed spd to the control amount calculation unit 20.

  As shown in FIG. 1, the control amount calculation unit 20 includes a target output calculation unit 21 and a target control amount calculation unit (setting unit) 22. The target output calculation unit 21 calculates the target power (target output) P of the engine 1 based on the target driving force Ftgt and the vehicle speed spd acquired from the target driving force calculation unit 10. The target output calculation unit 21 calculates the target power P by multiplying the target driving force Ftgt and the vehicle speed spd.

  The target control amount calculation unit 22 calculates a target control amount based on the target power P calculated by the target output calculation unit 21. Here, the target control amounts are a target engine speed nintgt that is a target value of the engine speed NIN and a target engine torque trqtgt that is a target value of the output torque TE of the engine 1. As described above, the input rotational speed (input shaft rotational speed) of the continuously variable transmission 2 corresponds to the engine rotational speed (output shaft rotational speed) NIN. In the following description, it is assumed that the target input rotational speed, which is the target value of the input rotational speed of the continuously variable transmission 2, is set to a value equal to the target engine rotational speed nintgt. That is, when the target rotational speed indicates the target value of the rotational speed of the engine 1, it is described as “target engine rotational speed nintgt”, and when the target rotational speed indicates the target value of the input rotational speed of the continuously variable transmission 2, It is described as “target input rotation speed nintgt”.

  As shown in FIG. 1, the calculated target engine speed nintgt and target engine torque trqtgt are output from the target control amount calculation unit 22 to the control unit 30. The control unit 30 functions as an operation control unit that performs operation control of the engine 1 and a shift control unit that performs shift control of the continuously variable transmission 2. The control unit 30 is connected to the engine 1, and a command value for controlling the operation state of the engine 1 is output from the control unit 30 to the engine 1. The control unit 30 controls the engine 1 so as to realize the target engine rotation speed nintgt and the target engine torque trqtgt. The control unit 30 is connected to the continuously variable transmission 2, and a signal indicating a target value (target gear ratio) of the gear ratio is output from the control unit 30 to the continuously variable transmission 2. The control unit 30 determines the target speed ratio of the continuously variable transmission 2 so that the engine rotational speed NIN (input rotational speed of the continuously variable transmission 2) becomes the target engine rotational speed (target input rotational speed) nintgt. The continuously variable transmission 2 performs a shift according to the target gear ratio acquired from the control unit 30.

  The target control amount calculation unit 22 of the present embodiment basically makes the target engine speed nintgt proportional to the vehicle speed spd. That is, the target engine rotational speed nintgt is proportionally increased as the vehicle speed spd increases. This suppresses the driver from feeling uncomfortable with the engine sound during acceleration, as will be described below.

  During acceleration, although the vehicle speed spd increased, the engine speed NIN did not increase, or even if the engine speed NIN increased, the increase amount was not proportional to the increase in the vehicle speed spd. In this case, the driver may not feel an acceleration according to the change in the vehicle speed spd and may feel uncomfortable with the engine sound. On the other hand, by making the target engine speed nintgt proportional to the vehicle speed spd basically, it is possible to suppress the driver from feeling uncomfortable during acceleration.

  However, although the engine speed NIN increases in proportion to the vehicle speed spd, the engine sound pressure that is the sound pressure of the engine sound does not increase depending on the region of the engine speed NIN, and there is a feeling of stickiness. On the contrary, there is a problem that the engine sound pressure suddenly increases and the engine sound is felt noisy. This is because the engine rotational speed NIN and the engine sound pressure are in a non-linear relationship, as will be described below with reference to FIGS.

  FIG. 3 is a diagram showing an example of the relationship between the engine speed NIN and the engine sound pressure. FIG. 3 shows the engine sound pressure detected in the passenger compartment. Here, the engine sound is a sound generated with the operation of the engine 1 such as a combustion sound generated in the main body of the engine 1 or an exhaust sound generated in an exhaust passage (not shown) of the engine 1. The sound pressure when the sound generated during the operation of the engine 1 is detected in the passenger compartment is the engine sound pressure shown in FIG. In other words, the engine sound pressure is the volume of sound generated by the operation of the engine 1 that is actually felt by the driver (passenger).

  Reference numeral 101 (solid line) indicates an actually measured value of the engine sound pressure, and reference numeral 102 (broken line) indicates a calculated value of the engine sound pressure. The engine rotational speed NIN and the engine sound pressure 101, 102 are in a non-linear relationship, and as indicated by the symbol R1, the increase in the engine sound pressure 101, 102 is moderate or hardly increased with the increase in the engine rotational speed NIN. On the other hand, there is a region where the engine sound pressures 101 and 102 increase greatly as the engine rotational speed NIN increases, as indicated by reference numeral R2. For this reason, as will be described with reference to FIG. 4, depending on the acceleration condition, a phenomenon has occurred in which the engine sound pressure 101 does not increase so much or the engine sound pressure 101 increases excessively.

  FIG. 4 is a diagram illustrating an example of a temporal transition of the engine rotation speed NIN and the engine sound pressure 101 during acceleration. In FIG. 4, the horizontal axis represents time, and the vertical axis represents engine rotational speed NIN and engine sound pressure. When shift control of the continuously variable transmission 2 is performed in which the engine rotation speed NIN is uniformly proportional to the vehicle speed spd during acceleration, the increase in the engine sound pressure 101 as indicated by the symbol R3 or the phenomenon indicated by the symbol R4 The engine sound pressure 101 is excessively increased.

  In the present embodiment, as will be described below with reference to FIGS. 5 to 7, the target engine speed nintgt is corrected so that the increase amount of the engine sound pressure is proportional to the increase amount of the vehicle speed spd. Is done. As a result, it is possible to suppress an increase in the engine sound pressure from stagnation or an excessive increase in the engine sound pressure with respect to the increase in the vehicle speed spd during acceleration.

  Here, the increase amount of the engine sound pressure is proportional to the increase amount of the vehicle speed spd, for example, the relationship between the increase amount of the vehicle speed spd and the increase amount of the engine sound pressure is linear, that is, This indicates that the ratio between the increase amount of the vehicle speed spd and the increase amount of the engine sound pressure is constant. Even if the relationship between the increase amount of the vehicle speed spd and the increase amount of the engine sound pressure is not completely linear, the target engine rotation speed nintgt is corrected based on the sound pressure characteristics of the engine 1 to Compared with the case where the sound pressure characteristic of 1 is not taken into account, the relationship between the increase amount of the vehicle speed spd and the increase amount of the engine sound pressure is made more linear. It is included in making the amount of increase in sound pressure proportional. In other words, making the increase amount of the engine sound pressure proportional to the increase amount of the vehicle speed spd is based on the sound pressure characteristic of the engine 1 as compared with the case where the sound pressure characteristic of the engine 1 is not considered. In other words, the variation of the increase amount of the engine sound pressure with respect to the increase amount of the vehicle speed spd is suppressed, that is, the variation range of the ratio between the increase amount of the vehicle speed spd and the increase amount of the engine sound pressure is reduced.

  FIG. 5 is a diagram showing the relationship between the engine rotational speed NIN and the engine sound pressure in the engine 1. FIG. 6 shows a shift line when the engine rotational speed NIN is proportional to the vehicle speed spd (see reference numeral 202) and a shift line when the target engine rotational speed nintgt is corrected during acceleration by the control of this embodiment (reference numeral 203). FIG. FIG. 7 is a diagram for explaining the effect when the target engine speed nintgt is corrected during acceleration by the control of the present embodiment.

  In FIG. 5, reference numeral 201 indicates the sound pressure level in the passenger compartment with respect to the engine speed NIN. As described above, the engine sound pressure 201 includes the region R5 in which the increase in the engine sound pressure 201 stagnate with respect to the increase in the engine rotation speed NIN, and the engine sound pressure 201 significantly increases with respect to the increase in the engine rotation speed NIN. Region R6 to be present.

  As described above, although there is a variation in the increase amount of the engine sound pressure 201 with respect to the increase amount of the engine rotation speed NIN depending on the region of the engine rotation speed NIN, as shown by the reference numeral 202 in FIG. When shift control is performed to make NIN proportional to the vehicle speed spd, as will be described below with reference to FIG. 7, the increase in engine sound pressure during acceleration or the engine sound pressure excessively increases. To do.

  In FIG. 7, reference numeral 204 indicates a temporal transition of engine sound pressure when the engine speed NIN is proportional to the vehicle speed spd during acceleration (see reference numeral 206). Reference numeral 205 indicates the target engine speed in the present embodiment. The time transition of the engine sound pressure when the speed nintgt is corrected (see reference numeral 207) is shown. When the engine speed NIN is made proportional to the vehicle speed spd evenly during acceleration, corresponding to a region where the increase in the engine sound pressure is stagnant with respect to the increase in the engine speed NIN (see reference numeral R5 in FIG. 5), As indicated by reference numeral R7 in FIG. 7, a phenomenon occurs in which the engine sound pressure 204 does not increase even though the engine rotational speed 206 increases. Thus, when the engine sound pressure 204 does not increase so much, it is difficult for the driver to feel a sufficient acceleration feeling. For this reason, there is a problem that the region where the driver feels “feeling of stretching” is limited to a narrow region (acceleration condition) indicated by the arrow Y1.

  In contrast, in the present embodiment, the target engine rotational speed nintgt is corrected so that the increase amount of the engine sound pressure is proportional to the increase amount of the vehicle speed spd. That is, in the speed change line 203 (see FIG. 6) at the time of acceleration according to the present embodiment, the vehicle speed spd as indicated by reference numeral 210 in the region R5 where the increase in the engine sound pressure is stagnant with respect to the increase in the engine speed NIN. The engine speed NIN is greatly increased with respect to the increase amount. In this case, the engine speed NIN is increased by shifting the continuously variable transmission 2 to a lower gear ratio. Thereby, the fluctuation of the increase rate of the engine sound pressure 205 (see FIG. 7) is suppressed, and the time during which the increase of the engine sound pressure 205 is stagnated is shortened, so that the feeling of stagnation is suppressed and You can feel a sense of growth.

  On the other hand, in the region R6 in which the engine sound pressure greatly increases with respect to the increase in the engine rotational speed NIN in the speed change line 203 (see FIG. 6) at the time of acceleration according to the present embodiment, In contrast, an increase in the engine speed NIN is suppressed. In this case, the increase in the engine rotational speed NIN is moderated by shifting the continuously variable transmission 2 to a higher gear ratio. Thereby, it is possible to suppress an excessive increase in the engine sound pressure 205 (see FIG. 7) and to reduce a region where the engine sound is felt loud.

  Thus, by correcting the target engine rotational speed nintgt so that the increase amount of the engine sound pressure is proportional to the increase amount of the vehicle speed spd during acceleration, an appropriate engine sound pressure 205 is obtained under a wide range of acceleration conditions. Can be secured. As a result, the linear feeling with respect to the engine sound is improved, and the acceleration feeling is improved under a wide range of acceleration conditions. As shown by an arrow Y2 in FIG. 7, the driver can feel an “elongation” in acceleration in a wide speed range during acceleration.

  FIG. 8 is a diagram showing target values of the engine rotational speed NIN and the output torque TE during acceleration according to the present embodiment. In FIG. 8, reference numeral 103 indicates an isosonic pressure line connecting a combination (operating point) of the engine rotational speed NIN and the output torque TE at which the engine sound pressure becomes equal. Reference numeral 104 denotes an engine that is determined based on the sound pressure characteristic of the engine 1 (distribution of the equal sound pressure line 103) so that the increase amount of the vehicle speed spd and the increase amount of the engine sound pressure are proportional during acceleration. The characteristic line which shows the target value of rotational speed NIN and output torque TE is shown.

  As will be described below with reference to FIG. 9, at the time of acceleration, the target engine speed nintgt is determined based on the characteristic line 104 by adding a correction amount to a basic value proportional to the vehicle speed spd. To a value (a value that makes the increase amount of the vehicle speed spd and the increase amount of the engine sound pressure proportional to each other).

  FIG. 9 is a diagram for explaining correction contents of the target engine speed nintgt and the target engine torque trqtgt during acceleration according to the present embodiment. Reference numerals P1, P2, and P3 indicate equal power lines at which the output (power) of the engine 1 becomes equal. When the operating point of the engine 1 (combination of the engine rotational speed NIN and the output torque TE) is on the same equal power line, the output (power) of the engine 1 becomes equal. The output of the engine 1 becomes a large value in the order of the equal power line indicated by reference sign P1 to the equal power line indicated by reference sign P3.

  A method for correcting the target engine rotational speed nintgt will be described by taking as an example the case where the equal power line corresponding to the target power P calculated by the target output calculation unit 21 is the equal power line indicated by symbol P2. When the basic target engine speed nintgt calculated so that the engine speed NIN is proportional to the vehicle speed spd is a value indicated by the symbol NIN1, this corresponds to the intersection of the equal power line P2 and the characteristic line 104. The correction amount is added to the target engine speed nintgt so as to be the value NIN2. In other words, the target power P of the engine 1 is left as it is (on the same equal power line), and correction is performed to change the operating point of the engine 1 to a point on the characteristic line 104. In this case, the target engine torque trqtgt is changed from the value indicated by the symbol TE1 to the value indicated by the symbol TE2 in accordance with the correction of the target engine speed nintgt.

  Since the engine sound pressure varies depending not only on the engine rotational speed NIN but also on the output torque TE of the engine 1, in this embodiment, the correction amount of the target engine rotational speed nintgt is based on the engine rotational speed NIN and the output torque TE. Is set. A map that defines the correction amount of the target engine speed nintgt for each combination of the engine speed NIN and the output torque TE is stored in the target control amount calculation unit 22. The target control amount calculation unit 22 corrects the target engine speed nintgt with reference to the map during acceleration.

  Next, the operation of this embodiment will be described with reference to FIGS. 10 and 11. FIG. 10 is a flowchart showing the operation of this embodiment. FIG. 11 is a diagram illustrating the transition of the target value of the input rotation speed of the continuously variable transmission 2 when the control according to the present embodiment is performed.

  First, in step S10, the target driving force calculation unit 10 detects the vehicle speed spd. The target driving force calculation unit 10 detects the vehicle speed spd based on the detection result of the vehicle speed detection means 4.

  Next, in step S20, the target driving force calculation unit 10 detects the accelerator opening degree accp. The target driving force calculation unit 10 detects the accelerator opening degree accp based on the detection result of the accelerator opening degree detection means 3.

  Next, at step S30, the vehicle travel control apparatus 100 calculates a determination threshold value α based on the vehicle speed spd detected at step S10 and the accelerator opening degree accp detected at step S20. The determination threshold value α is a threshold value of the accelerator opening degree accp for determining whether or not the vehicle is in an acceleration state. In other words, it is determined whether or not the driver requests acceleration of the vehicle by the determination threshold value α. The determination threshold value α is calculated as, for example, a threshold value for determining whether or not the target driving force Ftgt calculated from the current vehicle speed spd and the accelerator opening degree accp is a value that increases the vehicle speed spd. When step S30 is executed, the process proceeds to step S40.

  In step S40, the vehicle travel control device 100 determines whether or not the accelerator opening degree accp detected in step S20 is larger than the determination threshold value α. As a result of the determination, if it is determined that the accelerator opening degree accp is larger than the determination threshold value α (step S40-Y), the process proceeds to step S50, and if not (step S40-N), this control is performed. The flow is terminated. If a negative determination is made in step S40, the target engine speed nintgt and the target engine torque trqtgt are set so that the engine speed NIN is proportional to the vehicle speed spd.

  In step S50, the vehicle traveling control device 100 sets an acceleration determination flag. The acceleration determination flag is set when the vehicle is in an acceleration state, that is, when the driver requests to accelerate the vehicle.

  Next, in step S60, the control unit 30 calculates a target input rotation speed nintgt that is a target value of the input rotation speed of the continuously variable transmission 2. As described above, the target input rotational speed nintgt is a value equal to the target engine rotational speed nintgt.

  The target output calculation unit 21 calculates the target power P based on the target driving force Ftgt calculated by the target driving force calculation unit 10. The target control amount calculation unit 22 calculates a target engine rotation speed nintgt based on the target power P. The target engine speed nintgt calculated in step S60 is a basic value calculated as a value that makes the engine speed NIN proportional to the vehicle speed spd. The target input rotation speed nintgt is set by the control unit 30 to a value equal to the target engine rotation speed nintgt. In FIG. 11, reference numeral 221 indicates the basic target input rotation speed nintgt calculated in step S60.

  Next, in step S70, the control unit 30 calculates a correction amount for the target input rotational speed nintgt. The correction amount of the target input rotation speed (target engine rotation speed) is calculated based on the input rotation speed and the accelerator opening degree accp (load state). In other words, the correction amount of the target input rotation speed nintgt is the same as the correction amount of the target engine rotation speed nintgt, while the target power P of the engine 1 remains unchanged and the operating point of the engine 1 is represented on the characteristic line 104 (see FIG. 9). It is calculated as a value to be changed to the point.

  The target control amount calculation unit 22 calculates a correction amount for the target engine speed nintgt with reference to a map stored in advance based on the engine speed NIN and the output torque TE. Similarly, the control unit 30 calculates a correction amount for the target input rotation speed nintgt based on the input rotation speed and the output torque TE with reference to a map stored in advance. In FIG. 11, reference numeral 223 indicates a correction amount of the target input rotation speed nintgt.

  Next, in step S80, the control unit 30 adds the correction amount 223 of the target input rotation speed nintgt calculated in step S70 to the target input rotation speed nintgt (221) calculated in step S60. In FIG. 11, reference numeral 222 indicates the target input rotation speed nintgt after the correction amount 223 of the target input rotation speed nintgt is added, that is, the final target input rotation speed nintgt. Further, the target control amount calculation unit 22 calculates the final target engine speed nintgt by adding the correction amount of the target engine speed nintgt calculated in step S70 to the target engine speed nintgt calculated in step S60. To do. When step S80 is executed, this control flow is returned.

  The control unit 30 controls the transmission of the continuously variable transmission 2 based on the final target input rotational speed nintgt (212) calculated in step S80, and the final target engine rotational speed nintgt calculated in step S80. And the engine 1 is controlled based on the target engine torque trqtgt set correspondingly.

  With the control described above, the target input rotation speed (target engine rotation speed) nintgt is set so that the increase amount of the engine sound pressure is proportional to the increase amount of the vehicle speed spd during acceleration. As a result, it is possible to suppress an increase in engine sound pressure during acceleration or an excessive increase in engine sound pressure, and to ensure an appropriate increase in engine sound pressure. As a result, the linear feeling with respect to the engine sound is improved, and the acceleration feeling is improved under a wide range of acceleration conditions.

  In the present embodiment, since the engine rotational speed NIN and the engine sound pressure both increase as the vehicle speed spd increases during acceleration, it is possible to appropriately give the driver a feeling of acceleration according to the change in the vehicle speed. .

  Here, instead of correcting the target input rotational speed (target engine rotational speed) nintgt, for example, a device for adjusting the sound pressure in the exhaust passage may be provided as a means for adjusting the engine sound pressure. In this case, it is difficult to make the engine sound pressure increase proportional to the vehicle speed spd increase. This is because the change amount of the engine sound pressure with respect to the change amount of the engine rotation speed NIN varies depending on the region of the engine rotation speed NIN, and the frequency component of the engine sound varies depending on the engine rotation speed NIN. On the other hand, in the present embodiment, the engine speed NIN is controlled according to the vehicle speed spd, based on a characteristic between the engine speed NIN and the engine sound pressure obtained in advance (engine sound pressure characteristic). . Thereby, it is possible to easily make the increase amount of the engine sound pressure proportional to the increase amount of the vehicle speed spd.

  In the present embodiment, the engine sound pressure that is proportionally increased with respect to the increase amount of the vehicle speed spd is the sound pressure of the engine sound detected in the vehicle interior. The sound pressure of the engine sound detected outside the room may be increased in proportion to the increase amount of the vehicle speed spd. Even in this case, it is possible to increase the engine sound pressure felt by the driver in accordance with the increase in the vehicle speed spd, and the effect of giving the driver a feeling of acceleration corresponding to the change in the vehicle speed spd is achieved. Can do.

  In the above, the correction amount of the target input rotation speed (target engine rotation speed) nintgt is calculated based on the input rotation speed and the accelerator opening degree accp, but instead, the target input rotation speed is based only on the input rotation speed. A correction amount of (target engine rotation speed) nintgt may be calculated.

  The above description has been made on the assumption that the target engine speed nintgt before correction at the time of acceleration is set as a value proportional to the vehicle speed spd. However, the basic target engine speed nintgt before correction is calculated. Is not limited to this. Even if the target engine speed nintgt before the correction is not a value proportional to the vehicle speed spd, the increase in the engine sound pressure is increased with respect to the increase in the vehicle speed spd during the acceleration by the correction considering the engine sound pressure characteristics of the present embodiment. The target engine speed nintgt can be corrected so as to be proportional.

  Here, when the increase amount of the engine sound pressure is proportional to the increase amount of the vehicle speed spd, although the acceleration linear feeling is improved, the engine sound pressure changes monotonously while the acceleration continues. The driver may not be able to get an appropriate acceleration feeling. In other words, the linear characteristic is a monotonous change, and may be a factor that impairs the feeling of acceleration.

  Therefore, in the present embodiment, when acceleration over a certain level continues for a long time, it is determined that the driver seeks further acceleration, and the target engine speed nintgt is calculated based on the engine sound pressure characteristics. The amount of acceleration is increased by increasing the engine sound pressure. In the following description, the target engine speed (target input speed) for making the increase amount of the engine sound pressure proportional to the correction amount calculated in step S70 of FIG. 10, that is, the increase amount of the vehicle speed spd. The correction amount of (speed) nintgt is the “first rotation speed correction amount”, and the correction amount of the target engine rotation speed (target input rotation speed) nintgt for increasing the engine sound pressure when the acceleration state described later continues. Is the “second rotational speed correction amount”.

  With reference to FIGS. 12 and 13, correction control for correcting the target engine rotational speed nintgt and the target input rotational speed nintgt of the continuously variable transmission 2 when acceleration continues for a predetermined time or more will be described.

  FIG. 12 is a flowchart showing the operation of correction control when acceleration continues for a predetermined time or more. The flowchart shown in FIG. 12 is repeatedly executed at predetermined intervals, for example.

  FIG. 13 is a time chart showing the transition of each value when the correction control of the target engine rotation speed (target input rotation speed) nintgt is performed when acceleration continues for a predetermined time or more. In FIG. 13, (a) shows a target input rotational speed nintgt, (b) shows an accelerator opening, and (c) shows an acceleration continuation determination flag described later. Reference numeral 401 denotes a target input rotation speed nintgt calculated so that the increase amount of the engine sound pressure is proportional to the increase amount of the vehicle speed spd during acceleration in the control flow shown in FIG. A target input rotation speed nintgt obtained by adding the first rotation speed correction amount to the input rotation speed nintgt is shown. Reference numeral 402 indicates a target input rotation speed nintgt to which the second rotation speed correction amount is added when acceleration continues for a predetermined time or more.

  Step S110 and step S120 in FIG. 12 can be similar to step S10 and step S20 in FIG. That is, when the vehicle speed spd is detected (step S110) and the accelerator opening degree accp is detected (step S120), the process proceeds to step S130.

  In step S130, the vehicle travel control device 100 calculates (detects) an accelerator opening change amount Δaccp, which is a change amount of the accelerator opening. The vehicle travel control device 100 calculates the accelerator opening change amount Δaccp from the accelerator opening accp detected in step S120 and the accelerator opening accp detected in step S120 this time when this control flow was executed last time.

  Next, in step S140, the vehicle travel control device 100 determines in advance a state in which the accelerator opening degree accp is greater than the determination threshold value α and the accelerator opening change amount Δaccp is equal to or greater than the change amount determination threshold value β. It is determined whether or not it continues for a predetermined time t0 or more. In step S140, it is determined whether or not the driver's acceleration request is continuously detected for the predetermined time t0 or more. The determination threshold value α is calculated in step S30 of FIG. 10, and is a threshold value of the accelerator opening degree accp for determining whether or not the vehicle is in an acceleration state.

  The change amount determination threshold value β is a threshold value of the accelerator opening change amount Δaccp for determining whether or not the driver requests acceleration of a certain level or higher. When the accelerator opening change amount Δaccp is equal to or greater than the change amount determination threshold β, it is determined that the driver requests acceleration of a certain level or more (an acceleration request of a certain level or more is detected). In FIG. 13, at time T1, a state is started in which it is determined that the accelerator opening degree accp is greater than the determination threshold value α and the accelerator opening change amount Δaccp is equal to or greater than the change amount determination threshold value β. Note that the change amount determination threshold β is not limited to a positive value.

  The state in which the driver keeps the accelerator opening accp at a constant opening larger than the determination threshold α and the acceleration continues, the state in which the driver gradually increases the accelerator pedal and accelerates, etc. If it continues for time t0 or more, an affirmative determination is made in step S140.

  As a result of the determination in step S140, if the accelerator opening degree accp is greater than the determination threshold value α and the accelerator opening change amount Δaccp is equal to or greater than the change amount determination threshold value β, the state continues for the predetermined time t0 or more. If it is determined (step S140-Y), the process proceeds to step S150. If not (step S140-N), the control flow is returned.

  In step S150, the vehicle travel control device 100 sets an acceleration continuation determination flag. The acceleration continuation determination flag is set when the driver's acceleration request is detected continuously for the predetermined time t0 or more. In FIG. 13, at time T2, the state where the accelerator opening degree accp is greater than the determination threshold value α and the accelerator opening change amount Δaccp is equal to or greater than the change amount determination threshold value β continues for the predetermined time t0 or more. Determination is made and an acceleration continuation determination flag is set.

  In step S160, the control unit 30 calculates a correction amount (second rotation speed correction amount) of the target input rotation speed nintgt of the continuously variable transmission 2. The second rotational speed correction amount is calculated with reference to a previously stored map based on the input rotational speed and the accelerator opening degree accp (load state). The second rotation speed correction amount is a value that increases the increase amount of the engine sound pressure with respect to the increase amount of the vehicle speed spd, in other words, the input rotation speed of the continuously variable transmission 2 with respect to the increase amount of the vehicle speed spd. It is a value that increases the amount of increase. For example, when the accelerator opening degree accp is large, the second rotation speed correction amount is set to a larger value than when the accelerator opening degree accp is small.

  The second rotational speed correction amount may be calculated based on the accelerator opening change amount Δaccp in addition to the accelerator opening accp or instead of the accelerator opening accp. In this case, for example, when the accelerator opening change amount Δaccp is large, the second rotation speed correction amount is set to a larger value than when the accelerator opening change amount Δaccp is small. Further, the second rotational speed correction amount may be adjusted based on the duration of the acceleration state. For example, when the duration time of the acceleration state is long, the second rotation speed correction amount is set to a larger value than when the duration time is short.

  Next, in step S170, the controller 30 adds the second rotational speed correction amount to the target input rotational speed nintgt. Correspondingly, the target engine speed nintgt is updated. The target engine rotational speed nintgt is corrected to a value equal to the target input rotational speed nintgt (402) after the second rotational speed correction amount is added. When step S170 is executed, this control flow is returned.

  The control unit 30 performs shift control of the continuously variable transmission 2 based on the target input rotation speed nintgt (402) calculated in step S170, and also corresponds to the target engine rotation speed nintgt calculated in step S170. Based on the set target engine torque trqtgt, the operation of the engine 1 is controlled.

  According to the present embodiment, when acceleration over a certain level continues for a long time (step S140-Y), it is determined that the driver is seeking further acceleration, and the target engine speed nintgt is changed to the engine sound pressure characteristic. The second rotational speed correction amount calculated based on the sum is added, and the acceleration feeling is improved by increasing the engine sound pressure. In this way, by increasing the engine sound pressure to give a further acceleration feeling, it is possible to give the driver an appropriate acceleration feeling.

  In the present embodiment, the control for setting the target engine rotation speed (target input rotation speed) nintgt so that the increase amount of the engine sound pressure is proportional to the increase amount of the vehicle speed spd is executed. Assuming that the target engine rotational speed (target input rotational speed) nintgt that increases the engine sound pressure when acceleration of a certain level or more continues for a long time is corrected, the target engine rotational speed to be corrected (target The setting method of (input rotation speed) nintgt is not limited to this. Even if control for increasing the engine sound pressure in proportion to the increase in vehicle speed spd is not performed, a target engine speed that increases the engine sound pressure when acceleration over a certain level continues for a long time ( By executing the correction of the target input rotational speed (nintgt), it is possible to give the driver a more appropriate acceleration feeling. That is, when a state where the driver requests acceleration continues for a long time, an appropriate acceleration feeling can be given to the driver by increasing the engine sound pressure to give a further acceleration feeling.

(Modification of the first embodiment)
A modification of the first embodiment will be described with reference to FIGS. 14 to 16.

  In the first embodiment (FIG. 10), the basic target engine speed calculated to be proportional to the vehicle speed spd in order to make the increase amount of the engine sound pressure proportional to the increase amount of the vehicle speed spd during acceleration. The speed nintgt was corrected so that the engine sound pressure increase was proportional to the vehicle speed spd increase during acceleration. In this modification, the target engine speed nintgt is calculated by selectively referring to two shift lines, that is, a shift line during acceleration and a shift line when not accelerating. In the acceleration shift line selected during acceleration, the target engine rotational speed nintgt is set so that the engine sound pressure increase is proportional to the vehicle speed spd increase.

  FIG. 14 is a diagram showing the relationship between the vehicle speed spd determined based on the two shift lines referred to in the present modification and the target input rotational speed nintgt. Reference numeral 301 indicates the relationship between the vehicle speed spd determined based on the shift line when not accelerating and the target input rotational speed nintgt. When not accelerating, the target input rotational speed nintgt is set to a value proportional to the vehicle speed spd.

  Reference numeral 302 indicates the relationship between the vehicle speed spd determined based on the shift line during acceleration and the target input rotational speed nintgt. In a region where the increase in engine sound pressure stagnate with respect to the increase in engine rotation speed NIN, as indicated by reference numeral 310, the target input rotation speed (target engine rotation speed) nintgt is increased with respect to the increase in vehicle speed spd during acceleration. Raise. On the other hand, in a region where the engine sound pressure greatly increases with an increase in the engine rotational speed NIN, as indicated by reference numeral 311, the target input rotational speed (target engine rotational speed) nintgt with respect to the increase amount of the vehicle speed spd during acceleration. Let the rise be small.

  The operation of this modification will be described with reference to FIGS. 15 and 16. FIG. 15 is a flowchart showing the operation of this modification. FIG. 16 is a diagram illustrating a transition of the target input rotation speed nintgt when the control according to the present modification is performed.

  Steps S210 to S250 can be the same as steps S10 to S50 in the first embodiment (FIG. 10). That is, the vehicle speed spd is detected (step S210), the accelerator opening degree accp is detected (step S220), and the determination threshold value α is calculated based on the vehicle speed spd and the accelerator opening degree accp (step S230). Is greater than the determination threshold value α (step S240). If a positive determination is made as a result of the determination (step S240-Y), an acceleration determination flag is set in step S250.

  Next, in step S260, the target input rotation speed nintgt is calculated by the control unit 30. The control unit 30 calculates the target input rotation speed nintgt based on the target engine rotation speed nintgt calculated by the target control amount calculation unit 22. The target input rotational speed (target engine rotational speed) calculated in step S260 is the target input rotational speed (target engine rotational speed) nintgt2 during acceleration in consideration of the characteristics of the engine sound pressure. The target input rotational speed nintgt2 in consideration of the characteristics of the engine sound pressure is calculated based on the shift line at the time of acceleration, and is a value that makes the increase amount of the engine sound pressure proportional to the increase amount of the vehicle speed spd. It is. In FIG. 16, reference numeral 313 indicates a target input rotational speed (target engine rotational speed) nintgt2 at the time of acceleration in consideration of characteristics of engine sound pressure. When step S260 is executed, this control flow is returned.

  When a negative determination is made in step S240 and the process proceeds to step S270, the target input rotational speed nintgt is calculated in step S270. The target input rotational speed nintgt calculated in step S270 is a value that makes the engine rotational speed NIN proportional to the vehicle speed spd. In FIG. 16, reference numeral 312 indicates the target input rotation speed (target engine rotation speed) nintgt calculated in step S270. When step S270 is executed, this control flow is returned.

(Second Embodiment)
The second embodiment will be described with reference to FIGS. 17 and 18. In the second embodiment, only differences from the first embodiment will be described.

  In the first embodiment, when the acceleration of a certain level or more continues for a long time, the second rotational speed correction amount is set to the target engine rotational speed (target input rotational speed) nintgt in order to increase the engine sound pressure. It was added. In the present embodiment, instead of this, two different shift lines are selectively used. During normal times other than when acceleration above a certain level continues for a long time, the target engine speed (target input speed) nintgt is set based on one shift line. In this case, the increase amount of the engine sound pressure is proportional to the increase amount of the vehicle speed spd. When it is determined that acceleration over a certain level has continued for a long time, the other shift line is referred to instead of the normal shift line so as to increase the engine sound pressure increase compared to the normal shift line. Is set to the target engine rotation speed (target input rotation speed) nintgt.

  The operation of this embodiment will be described with reference to FIGS.

  FIG. 17 is a flowchart showing the operation of the present embodiment. The flowchart shown in FIG. 17 is repeatedly executed at predetermined intervals, for example.

  FIG. 18 is a time chart showing the transition of each value when shift control based on different shift lines is performed according to the acceleration duration. In FIG. 18, (a) shows the target input rotational speed nintgt, (b) shows the accelerator opening, and (c) shows the acceleration continuation determination flag. Reference numeral 501 indicates the transition of the target input rotational speed nintgt when shift control based on the normal shift line is performed except when acceleration of a certain level or more continues for a long time. In the shift control based on the normal shift line, the engine sound pressure increase is proportional to the vehicle speed spd increase.

  On the other hand, reference numeral 502 indicates a temporal transition of the target input rotational speed nintgt when the shift control based on the shift line is performed when acceleration of a certain level or more continues for a predetermined time or more. Reference numeral 503 indicates that the acceleration continuation determination flag is set to ON at time T2, and the control shifts from increasing the engine sound pressure to an increase in the vehicle speed spd to increasing the engine sound pressure. The transition of the target input rotational speed nintgt in this case is shown.

  In the flowchart shown in FIG. 17, Steps S310 to S340 can be the same as those in the first embodiment (FIG. 12). That is, when the vehicle speed spd is detected (step S310), the accelerator opening accp is detected (step S320), and the accelerator opening change amount Δaccp is calculated (step S330), the accelerator opening accp is larger than the determination threshold α. And whether or not the accelerator opening change amount Δaccp is equal to or greater than the change amount determination threshold β is determined for a predetermined time t0 or more. As a result of the determination, it is determined that the state where the accelerator opening degree accp is greater than the determination threshold value α and the accelerator opening change amount Δaccp is equal to or greater than the change amount determination threshold value β continues for the predetermined time t0 or more. If so (step S340-Y), the process proceeds to step S350. If not (step S340-N), the process proceeds to step S370.

  When the acceleration continuation determination flag is set in step S350, the process proceeds to step S360. In step S360, the control unit 30 calculates a target input rotational speed (target engine rotational speed) nintgt3 in consideration of the engine sound pressure characteristics. In step S360, the target input rotation speed is set to a value that increases the increase in engine sound pressure when the acceleration request continues for a predetermined time t0 or more. The target control amount calculation unit 22 calculates a target input rotation speed (target engine rotation speed) nintgt3 based on a shift line when acceleration of a certain level or more continues for a predetermined time t0 or more. When step S360 is executed, the control flow is returned.

  When a negative determination is made in step S340 and the process proceeds to step S370, the target input rotation speed (target engine rotation speed) nintgt is calculated by the control unit 30 in step S370. The target control amount calculation unit 22 calculates a target input rotational speed (target engine rotational speed) nintgt based on a normal shift line other than when a certain level or more of acceleration continues for the predetermined time t0 or more. When step S370 is executed, this control flow is returned.

  When the acceleration continuation determination flag is set in step S350, engine sound pressure characteristics are taken into account from the target input rotational speed (target engine rotational speed) nintgt (see reference numeral 501 in FIG. 18) based on the normal shift line. If the engine rotational speed NIN is increased at once to the target input rotational speed (target engine rotational speed) nintgt3 (see reference numeral 502 in FIG. 18), there is a possibility that a shift shock will increase. It is desirable to gradually increase the rotation speed.

1 is a block diagram according to a first embodiment of a vehicle travel control device of the present invention. FIG. It is a figure which shows the correspondence of the accelerator opening degree and vehicle speed, and target drive force in 1st Embodiment of the vehicle travel control apparatus of this invention. It is a figure which shows an example of the relationship between an engine speed and an engine sound pressure. It is a figure which shows an example of the time transition of the engine speed at the time of acceleration at the time of making an engine speed proportional to a vehicle speed, and an engine sound pressure. It is a figure which shows the relationship between the engine rotational speed and engine sound pressure of 1st Embodiment of the vehicle travel control apparatus of this invention. In the first embodiment of the vehicle travel control device of the present invention, it is a diagram showing a shift line when the engine rotation speed is proportional to the vehicle speed and a shift line when the target engine rotation speed is corrected during acceleration. It is a figure for demonstrating the effect when the target engine rotational speed is correct | amended at the time of acceleration in 1st Embodiment of the vehicle travel control apparatus of this invention. It is a diagram which shows the target value of the engine speed and output torque at the time of acceleration of 1st Embodiment of the vehicle travel control apparatus of this invention. It is a figure for demonstrating the correction content of the target engine rotational speed and target engine torque at the time of the acceleration of 1st Embodiment of the vehicle travel control apparatus of this invention. It is a flowchart which shows operation | movement of 1st Embodiment of the vehicle travel control apparatus of this invention. It is a figure which shows transition of the target value of input rotational speed when control of 1st Embodiment of the vehicle travel control apparatus of this invention is performed. It is a flowchart which shows the operation | movement of the correction | amendment control which adjusts the raise of an engine sound pressure based on the continuation time of acceleration in 1st Embodiment of the vehicle travel control apparatus of this invention. It is a time chart which shows transition of each value when correction | amendment control which adjusts the raise of an engine sound pressure is made | formed based on the continuation time of acceleration in 1st Embodiment of the vehicle travel control apparatus of this invention. It is a figure which shows the relationship between the vehicle speed determined based on two shift lines, and the target input rotational speed in the modification of 1st Embodiment of the vehicle travel control apparatus of this invention. It is a flowchart which shows operation | movement of the modification of 1st Embodiment of the vehicle travel control apparatus of this invention. It is a figure which shows transition of the target input rotational speed when control of the modification of 1st Embodiment of the vehicle travel control apparatus of this invention is performed. It is a flowchart which shows operation | movement of 2nd Embodiment of the vehicle travel control apparatus of this invention. It is a time chart which shows transition of each value when shift control based on a different shift line is made according to continuation time of acceleration in a 2nd embodiment of a vehicle run control device of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Engine 2 Continuously variable transmission 3 Accelerator opening degree detection means 4 Vehicle speed detection means 10 Target driving force calculation part 20 Control amount calculation part 21 Target output calculation part 22 Target control amount calculation part 30 Control part 100 Vehicle travel control apparatus 103 Isotone Pressure line 104 Characteristic line accp Accelerator opening Δaccp Accelerator opening change amount Ftgt Target driving force NIN Engine rotational speed nintgt Target engine rotational speed nintgt2 Target input rotational speed considering engine sound pressure characteristics P1, P2, P3 Equipotential line P Target power spd Vehicle speed TE Output torque trqtgt Target engine torque α Determination threshold β Change amount determination threshold

Claims (3)

The internal combustion engine and a continuously variable transmission that transmits the output of the internal combustion engine to a drive shaft are provided in a vehicle, and the internal combustion engine is configured to achieve a target rotational speed that is a target value of the rotational speed of the internal combustion engine. A vehicle travel control device for controlling an engine and the continuously variable transmission,
Setting means for setting the target rotational speed based on the vehicle speed;
Acceleration request detection means for detecting the magnitude of the driver's acceleration request;
Continuation determination means for determining whether or not the acceleration request is continuously detected for a predetermined time or more by the acceleration request detection means ;
State determination means for determining whether or not the vehicle is in an acceleration state ,
The setting means includes
If the state determination means determines that the vehicle is in an acceleration state and the continuation determination means does not determine that the acceleration request has been continuously detected for the predetermined time or more, the vehicle speed increases. The target rotational speed is set based on a characteristic line determined so that the amount and the increase in the sound pressure of the internal combustion engine are proportional to each other,
When it is determined by the continuation determination means that the acceleration request is continuously detected for the predetermined time or more, it is determined that the vehicle is in an acceleration state, and the acceleration request is continued for the predetermined time or more. The target rotational speed is set so as to increase the amount of increase in the sound pressure of the internal combustion engine relative to the amount of increase in the vehicle speed as compared to the case where it is not determined that the acceleration is detected. When the time is long, the target rotational speed is set so as to increase the amount of increase in the sound pressure of the internal combustion engine with respect to the amount of increase in the vehicle speed as compared with the case where the duration is short. Vehicle travel control device. In the vehicle travel control device according to claim 1 ,
The setting means increases the target rotational speed as the vehicle speed increases, and in a region of the rotational speed where the increase amount of the sound pressure is small relative to the rotational speed increase amount, By increasing the increase amount of the target rotation speed relative to the increase amount of the vehicle speed as compared with the region of the rotation speed where the increase amount of the sound pressure relative to the increase amount is large, the sound is increased relative to the increase amount of the vehicle speed. A vehicle travel control device characterized in that the amount of increase in pressure is proportional. In the vehicle travel control device according to claim 1 or 2 ,
The vehicle travel control apparatus characterized in that the target rotational speed is realized by changing the rotational speed by shift control of the continuously variable transmission.

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