Vehicle control system and control method

Abstract

Provided are a control system and a control method for a vehicle that set a target acceleration to reliably improve acceleration responsiveness at the start of acceleration of the vehicle. A control system for a vehicle includes a drive source, an accelerator opening degree sensor that detects an accelerator opening degree, and a control device that controls the drive source. A second target acceleration which increases at a rate of change greater than that of the first target acceleration applied in the first control is set so that the jump of the vehicle increases within a range less than a prescribed jump; and a second control for controlling the torque of the drive source on the basis of a second target acceleration, the second control being performed first when the speed of change in the accelerator opening degree is increased to a predetermined value or more in a state in which the vehicle is not accelerated, and the first control being performed after the second target acceleration set in the second control reaches a predetermined acceleration.

Description

Technical Field

[0001] This invention relates to a control system and control method for a vehicle that sets a target acceleration and controls the torque of the drive source based on the target acceleration. Background Technology

[0002] Previously, techniques were known to set a target acceleration based on the driver's throttle operation, and to control the torque of drive sources such as engines and electric motors in a way that achieves that target acceleration. For example, Patent Document 1 describes a technique for setting a target acceleration in a manner that produces the maximum jump when the throttle opening is increased by 5 to 10% from a stable driving state. Additionally, Patent Document 2 describes a technique for determining a target value for acceleration (jump) and setting a target acceleration based on that target value.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2016-217293

[0006] Patent Document 2: Japanese Patent Application Publication No. 2008-120183.

[0007] The technical problem that the invention aims to solve

[0008] Based on the ongoing research conducted by the inventors of this application, it was discovered that at the start of vehicle acceleration (when the driver begins to depress the accelerator pedal), the vehicle's acceleration is small, so the driver may not perceive the acceleration, resulting in a perceived poor acceleration responsiveness. In particular, it was discovered that the vehicle's acceleration is less than the minimum acceleration that a person can perceive as the start of acceleration (e.g., 0.27–0.3 m / s²). 2 At a point around 100°C (or below this minimum perceived acceleration, aptly termed "minimum perceived acceleration"), the driver cannot perceive acceleration. When the vehicle's acceleration remains below this minimum perceived acceleration for an extended period, the driver tends to experience poor acceleration responsiveness.

[0009] Therefore, in order to improve acceleration responsiveness at the start of acceleration, it is desirable to set a target acceleration in a way that rapidly increases the vehicle's acceleration, thereby shortening the time it takes for the vehicle's acceleration to fall below the minimum perceived acceleration. In this case, setting the target acceleration by increasing the vehicle's jerkiness can be considered. However, if the jerkiness is too large, it may cause discomfort to the driver. Furthermore, the technology described in Patent Documents 1 and 2 is not sufficient to reliably improve acceleration responsiveness at the start of acceleration. Summary of the Invention

[0010] The present invention was made to solve the problems of the prior art mentioned above, and its purpose is to provide a vehicle control system and control method that can set a target acceleration to reliably improve the acceleration responsiveness of the vehicle at the start of acceleration.

[0011] Technical means for solving technical problems

[0012] To achieve the above objectives, the vehicle control system of the present invention comprises: a drive source that generates driving force for the vehicle; a throttle opening sensor that detects throttle opening, which is the opening of an accelerator pedal in the vehicle; and a control device configured to control the drive source based on the throttle opening detected by the throttle opening sensor. The control device is configured to perform: a first control, wherein the first control sets a target acceleration that increases with the increase of the throttle opening and controls the torque of the drive source based on the set target acceleration; and a second control, wherein the second control sets a target acceleration that increases at a rate of change greater than the target acceleration applied in the first control, so that the vehicle's acceleration increases within a range less than a predetermined acceleration, and controls the torque of the drive source based on the set target acceleration. When the rate of change of the throttle opening increases by a predetermined value or more in a state where the vehicle is not accelerating, the second control is performed first, and the first control is performed after the target acceleration set in the second control reaches the predetermined acceleration.

[0013] According to the present invention configured in this way, at the start of vehicle acceleration, acceleration control (second control) is initially performed based on a target acceleration that causes the vehicle's acceleration spurt to increase within a range less than a predetermined spurt. Therefore, excessive spurts can be suppressed, and the acceleration can rapidly increase to reach the predetermined acceleration. This suppresses unpleasant sensations to the driver caused by excessive spurts and improves acceleration responsiveness. As a result, the driver's driving experience at the start of acceleration is improved.

[0014] In this invention, preferably, the control device is configured to set the target acceleration to be applied in the second control based on at least one of the following: the rate of increase of throttle opening, the speed of the vehicle, the gear stage of the transmission of the vehicle, the rate of change of the target acceleration applied in the first control, and the gradient of the road on which the vehicle travels.

[0015] By setting the target acceleration applied in the second control based on such a specified jump, it is possible to suppress the unpleasant feelings caused to the driver by large jumps, as well as adverse situations caused by target accelerations with large changes in magnitude and rate of change.

[0016] In this invention, it is preferable that the acceleration is defined based on the minimum acceleration at which a person can perceive the start of acceleration.

[0017] By implementing the second control described above, and by rapidly bringing the acceleration to the specified acceleration, i.e., the minimum perceived acceleration, the driver can quickly perceive the vehicle's acceleration at the start of acceleration, thus effectively improving acceleration responsiveness.

[0018] In a preferred embodiment of the present invention, the acceleration is specified to be 0.27–0.3 m / s². 2 The acceleration within the range.

[0019] In this invention, it is preferable that the control device is configured such that even if the rate of change of throttle opening increases by a predetermined value or more when the rate of increase of throttle opening is greater than or more than the predetermined value, the second control is not performed, but the first control is performed instead.

[0020] According to the present invention configured in this way, for example, when the throttle operation is caused by the vibration of the foot due to the impact of the vehicle going over a step, it is possible to prevent large acceleration from being generated by the second control.

[0021] In this invention, it is preferable that the control device is configured such that even if the rate of change of throttle opening increases by a predetermined value or more when the throttle opening increases from the state where the vehicle is stationary, the second control is not performed, but the first control is performed.

[0022] According to the present invention configured in this way, it is possible to prevent the so-called throttle jerking phenomenon caused by transmission gap engagement from the large acceleration generated by the second control when starting from a stop of the vehicle.

[0023] In this invention, it is preferred that the rate of change of throttle opening increases by more than a predetermined value, which is when the rate of change of throttle opening increases by more than 1%.

[0024] According to the present invention configured in this way, it is possible to control the acceleration of the vehicle to a certain extent after confirming the driver's intention to accelerate based on the accelerator pedal.

[0025] In other viewpoints, the vehicle control method of the present invention is executed by a control device in a vehicle having a drive source, a throttle opening sensor, and a control device. The drive source generates the driving force of the vehicle, the throttle opening sensor detects the throttle opening, which is the opening of the accelerator pedal of the vehicle, and the control device is configured to control the drive source based on the throttle opening detected by the throttle opening sensor, and includes the following steps: performing a first control, which sets a target acceleration that increases according to the increase of the throttle opening, and controls the torque of the drive source based on the set target acceleration; performing a second control, which sets a target acceleration that increases at a rate of change greater than the target acceleration applied in the first control, so that the jump of the vehicle increases within a range less than a predetermined jump, and controls the torque of the drive source based on the set target acceleration; and performing the second control first when the rate of change of the throttle opening increases by a predetermined value or more when the vehicle is not accelerating, and performing the first control after the target acceleration set in the second control reaches the predetermined acceleration.

[0026] The effects of the invention

[0027] According to the vehicle control system and control method of the present invention, a target acceleration can be set to reliably improve the acceleration response of the vehicle at the start of acceleration. Attached Figure Description

[0028] Figure 1 This is a schematic structural diagram of a vehicle that uses a vehicle control system based on an embodiment of the present invention.

[0029] Figure 2 This is an explanatory diagram regarding basic acceleration control using a first target acceleration based on an embodiment of the present invention.

[0030] Figure 3 This is an explanatory diagram regarding acceleration control using a second target acceleration based on an embodiment of the present invention.

[0031] Figure 4 This is a flowchart illustrating the acceleration control based on an embodiment of the present invention.

[0032] Figure 5 This is a control mapping diagram representing the convergence speed based on an embodiment of the present invention.

[0033] Symbol Explanation

[0034] 1. Driver Source

[0035] 3. Control device

[0036] 5. Throttle opening sensor

[0037] 7. Vehicle speed sensor

[0038] 9. Accelerometer

[0039] 10. Vehicle control system

[0040] 20 vehicles. Detailed Implementation

[0041] Hereinafter, with reference to the accompanying drawings, a vehicle control system and control method based on an embodiment of the present invention will be described.

[0042] [Overall Structure]

[0043] First, refer to Figure 1 The overall structure of the vehicle control system based on this embodiment will be described. Figure 1 This is a schematic structural diagram of a vehicle that uses a vehicle control system based on this embodiment.

[0044] like Figure 1 As shown, vehicle 20 is equipped with a vehicle control system 10, which includes: a drive source 1 that generates driving force for vehicle 20, such as an engine (internal combustion engine) or an electric motor; a control device 3 configured to control drive source 1; a throttle opening sensor 5 that detects the opening of the accelerator pedal (not shown) of vehicle 20; a vehicle speed sensor 7 that detects the speed (vehicle speed) of vehicle 20; and an acceleration sensor 9 that detects the acceleration of vehicle 20. In addition, vehicle 20 is also equipped with various sensors other than these sensors 5, 7, and 9 (for example, if vehicle 20 has a transmission, a gear level sensor that detects the gear level set for that transmission, etc.).

[0045] The control device 3 is composed of a computer, which includes: one or more processors 3a (typically CPU), various programs deployed and executed on the processor 3a (including basic control programs such as OS, and application programs that start on the OS and perform specific functions), and memory 3b such as ROM and RAM for storing various data.

[0046] In this embodiment, the control device 3 sets the target acceleration that the vehicle should produce based on the throttle opening detected by the throttle opening sensor 5 and the vehicle speed detected by the vehicle speed sensor 7, and controls the torque of the drive source 1 in a manner that achieves the target acceleration. The details of the control performed by the control device 3 will be described later.

[0047] [Control Methods]

[0048] Next, refer to Figure 2 and Figure 3 The control method performed by the control device 3 in this embodiment will be explained.

[0049] First, refer to Figure 2 The basic acceleration control in this embodiment will be explained. Figure 2 In the figure, curve G11 represents the time variation of throttle opening, and curve G12 represents the time variation of the basic (as a basis) first target acceleration set according to the throttle opening.

[0050] like Figure 2 As shown, at time t11, while the vehicle 20 is driving steadily, the driver depresses the accelerator pedal, thereby increasing the throttle opening (furthermore, "driving steadily" here refers to a non-accelerating state where the vehicle speed is greater than 0 (the same applies below), and the first target acceleration is essentially set to 0). Specifically, at time t11, the rate of change of the throttle opening increases by more than 1%. From this time t11, the control device 3 sets the first target acceleration that increases according to the increase in throttle opening, and controls the torque of the drive source 1 in a manner that achieves this first target acceleration. In this case, the control device 3 sets the first target acceleration based on the vehicle speed, the gear stages of the transmission possessed by the vehicle 20, etc., in addition to the throttle opening. For example, the first target acceleration can be set using the method described in Patent Document 1 above.

[0051] However, as mentioned above, at the start of acceleration of vehicle 20 (when the driver begins to depress the accelerator pedal), the driver cannot perceive acceleration when the acceleration of vehicle 20 is relatively low. More specifically, the driver cannot perceive acceleration when the target acceleration is less than a specified acceleration Ac1. This specified acceleration Ac1 corresponds to the minimum acceleration at which a person can perceive the start of acceleration (the minimum perceptible acceleration), for example, 0.27–0.3 m / s². 2 The acceleration within the range.

[0052] Here, based on Figure 2 When the first target acceleration, as shown by curve G12, causes vehicle 20 to accelerate, during the period T11 from the start of acceleration at time t11 to time t12, the driver cannot perceive the acceleration because the first target acceleration is less than the specified acceleration Ac1. When this period T11 is long, the driver tends to have poor perceived acceleration responsiveness.

[0053] Therefore, in this embodiment, in order to improve the acceleration responsiveness at the start of acceleration and rapidly increase the acceleration of vehicle 20, the time during which the acceleration of vehicle 20 is less than the predetermined acceleration Ac1 is shortened. To this end, in this embodiment, the control device 3 sets a second target acceleration at the start of acceleration, which increases at a rate (slope) greater than that of the first target acceleration. In this case, the control device 3 sets the second target acceleration in a manner that increases the jerk (acceleration) of vehicle 20 within a range that will not cause discomfort to the driver; specifically, it sets the jerk of vehicle 20 within a range less than the predetermined jerk.

[0054] Next, refer to Figure 3 The acceleration control using the second target acceleration based on this embodiment will be explained. Figure 3 In the diagram, curve G21 represents the time change of throttle opening, curve G22 represents the time change of the rate of change of throttle opening, curve G23 represents the time change of the first target acceleration, curve G24 represents the time change of the second target acceleration, and curve G25 represents the time change of the jump of vehicle 20 (equivalent to the target jump).

[0055] like Figure 3 As shown, at time t21, during the stable driving of vehicle 20 (period T21), the rate of change of throttle opening increases by more than 1% due to the driver pressing the accelerator pedal (curve G21). From this time t21, in order to increase the acceleration of vehicle 20 within a range less than a predetermined acceleration (curve G25), control device 3 sets a second target acceleration (curve G24, arrow Ar1) that increases at a rate (slope) greater than the first target acceleration, and controls the torque of drive source 1 based on this second target acceleration. Furthermore, when setting the second target acceleration in this way, control device 3 also calculates the first target acceleration in parallel with the second target acceleration (curve G23). However, at this time, control device 3 performs acceleration control based on the second target acceleration (period T22), and does not use the first target acceleration for acceleration control.

[0056] In detail, the control device 3 sets the aforementioned predetermined jump based on at least one of the following: the rate of increase in throttle opening, vehicle speed, the gear stages of the transmission of the vehicle 20, the rate of change (slope) of the first target acceleration, and the gradient of the road on which the vehicle 20 travels. Furthermore, the control device 3 sets a second target acceleration in a manner that causes the jump of the vehicle 20 to increase within a range smaller than the predetermined jump. For example, the control device 3 sets the second target acceleration in a manner that causes the jump of the vehicle 20 to rapidly increase to the predetermined jump and maintain that predetermined jump.

[0057] Subsequently, at time t22, the second target acceleration reaches the predetermined acceleration Ac1. The predetermined acceleration Ac1 is based on the aforementioned minimum perceived acceleration, pre-set, for example, 0.27–0.3 m / s². 2 The acceleration is within the range of the first target acceleration. From such a moment t22, the control device 3 stops increasing the second target acceleration at a rate greater than that of the first target acceleration, and sets the second target acceleration in such a way that the second target acceleration is maintained at the difference from the first target acceleration and changes at the same rate (slope) as the first target acceleration, and controls the torque of the drive source 1 based on the second target acceleration.

[0058] Subsequently, at time t23, the rate of change of throttle opening changes from an increasing state to a state of decreasing by a predetermined value or more; that is, the rate of change of throttle opening changes from an increasing state to a decreasing state of a predetermined value or more (curve G22). From time t23, control device 3 adjusts the second target acceleration (arrow Ar2) in a manner that gradually converges to the first target acceleration, and controls the torque of drive source 1 based on the second target acceleration. Thus, by making the second target acceleration converge to the first target acceleration, and by continuing to use the second target acceleration, it prevents the generation of acceleration beyond the driver's expectations, which would make subsequent driving operations difficult. In particular, control device 3 determines the convergence speed for making the second target acceleration converge to the first target acceleration based on the first target acceleration and the rate of change of throttle opening (the operation speed of the accelerator pedal), and adjusts the second target acceleration based on the convergence speed. More specifically, control device 3 determines the convergence speed by referring to a control mapping diagram that corresponds to the first target acceleration and the rate of change of throttle opening and specifies the convergence speed. Thus, the second target acceleration converges to the first target acceleration in a way that does not cause any discomfort to the driver.

[0059] Then, at time t24, the adjusted second target acceleration reaches the first target acceleration, that is, the convergence of the second target acceleration to the first target acceleration is completed, so the control device 3 ends the acceleration control based on the second target acceleration and starts the acceleration control based on the first target acceleration.

[0060] Furthermore, the control performed from time t21 to time t22 (during period T22) corresponds to the "second control" in this invention, and the control performed after time t22 corresponds to the "first control" in this invention. The "first control" is essentially acceleration control using a first target acceleration, but it also includes acceleration control using a second target acceleration that changes at the same rate of change (slope) as the first target acceleration. On the other hand, the "second control" is acceleration control using a second target acceleration that increases at a rate of change greater than that of the first target acceleration.

[0061] [Control Flow]

[0062] Next, refer to Figure 4 A flowchart illustrating acceleration control based on an embodiment of the present invention will be described. This process is repeatedly executed by the control device 3 at predetermined intervals. Specifically, the processor 3a within the control device 3 reads a program stored in the memory 3b and executes the program to implement the control involved in the process.

[0063] First, in step S10, the control device 3 acquires at least various information, such as the detection values ​​detected by the throttle opening sensor 5, the vehicle speed sensor 7, and the acceleration sensor 9. Furthermore, the control device 3 calculates the average value of the detection value from the throttle opening sensor 5 over 30 ms (corresponding to the throttle opening, hereinafter referred to as "apsfil"), the slope of the apsfil over 100 ms (corresponding to the change in throttle opening, hereinafter referred to as "dapsfil"), and the slope of the dapsfil over 1 second (hereinafter referred to as "ddapsfil").

[0064] Next, in step S11, the control device 3 determines whether the vehicle 20 is in a stable driving state. Specifically, if the vehicle speed detected by the vehicle speed sensor 7 is greater than 0 (meaning the vehicle 20 is not stopped) and the acceleration detected by the acceleration sensor 9 (or the target acceleration can be used instead of the detected acceleration) is 0, the control device 3 determines that the vehicle 20 is in a stable driving state (step S11: Yes). In this case, the control device 3 proceeds to step S12.

[0065] In contrast, if the control device 3 does not determine that the vehicle 20 is in a stable driving state (step S11: No), for example, if the vehicle 20 is stopped or the vehicle 20 has already accelerated, step S12 is not performed. In particular, in this embodiment, when the vehicle 20 accelerates from a stopped state, the control device 3 does not perform acceleration control based on the second target acceleration (in this case, acceleration control based on the first target acceleration is performed). This is because if the acceleration increases significantly from a stopped state by acceleration control based on the second target acceleration, it may cause a so-called throttle jerking phenomenon due to transmission gap engagement.

[0066] Next, in step S12, the control device 3 determines whether the aforementioned dapsfil is above a predetermined value. Here, the control device 3 uses dapsfil to determine whether the rate of change of the throttle opening has increased by more than 1%. By performing this determination, the driver's intention to operate the accelerator pedal is determined to some extent, thereby performing acceleration control of the vehicle 20. The result of step S12 is that if the control device 3 determines that dapsfil is above the predetermined value (step S12: Yes), it proceeds to step S13. Conversely, if the control device 3 does not determine that dapsfil is above the predetermined value (step S12: No), that is, if dapsfil is less than the predetermined value, it returns to step S12 without proceeding to step S13.

[0067] Next, in step S13, the control device 3 determines whether dapsfil has updated to its maximum value and whether ddapsfil is less than a predetermined value. Here, the driver's acceleration intention (acceleration request) is first confirmed by determining whether the sequentially obtained dapsfil (larger changes) has updated to its maximum value. Additionally, it is confirmed by determining whether ddapsfil is less than a predetermined value that no throttle operation has occurred, for example, due to unexpected foot vibration caused by the impact when the vehicle 20 crosses a step. In such a situation, the vehicle 20 should not experience large acceleration, therefore acceleration control based on a second target acceleration is not performed (in this case, acceleration control based on a first target acceleration is performed).

[0068] If the result of step S13 is that the control device 3 does not determine that dapsfil has been updated to its maximum value and ddapsfil is less than a specified value (step S13: No), then the process proceeds to step S14, where a first target acceleration is set, and the torque of the drive source 1 is controlled in a manner that achieves this first target acceleration. In this case, the control device 3 sets the first target acceleration based on the throttle opening, vehicle speed, gear stages of the transmission, etc. For example, the control device 3 can set the first target acceleration using the method described in Patent Document 1 above.

[0069] In contrast, if the result of step S13 is that the control device 3 determines that dapsfil has been updated to its maximum value and ddapsfil is less than a predetermined value (step S13: Yes), then proceed to step S15, set a second target acceleration, and control the torque of the drive source 1 in a manner that achieves the second target acceleration. Specifically, the control device 3 sets a predetermined jump based on ddapsfil (corresponding to the rate of increase of throttle opening), vehicle speed, gear stage of the transmission, rate of change (slope) of the first target acceleration, and gradient of the road on which the vehicle 20 travels, and sets a second target acceleration that increases at a rate greater than that of the first target acceleration, so that the jump of the vehicle 20 increases within a range less than the predetermined jump (typically, the second target acceleration is set in a manner that causes the jump of the vehicle 20 to rise rapidly to the predetermined jump and maintain the predetermined jump).

[0070] Here, we illustrate a specific method for setting the second target acceleration based on the control device 3 (specifically, a method for setting the predetermined jump for the second target acceleration). First, when ddapsfil is large, the control device 3 sets a large predetermined jump to significantly increase the second target acceleration. In this case, the control device 3 uses the maximum value of ddapsfil to accurately determine the degree of the driver's acceleration intention. Furthermore, at low vehicle speeds (around 10-30 km / h) and high vehicle speeds (above 60 km / h), the control device 3 sets a smaller predetermined jump to prevent the difference between the second and first target accelerations from widening. On the other hand, at medium vehicle speeds (around 30-60 km / h), the control device 3 sets a larger predetermined jump to significantly increase the second target acceleration. Additionally, when the gear stage is a low-speed gear (e.g., 1st gear), the control device 3 sets a smaller predetermined jump to suppress impact. Furthermore, when the rate of change (slope) of the first target acceleration is small, a smaller predetermined jump is set. This is because, when the rate of change of the first target acceleration is small, if the rate of change of the second target acceleration is increased, then at the beginning of the stage where the second target acceleration changes using the rate of change (slope) of the first target acceleration (refer to...) Figure 3 At time t22 and during period T23, the rate of change of the second target acceleration decreases sharply, which would impair the continuity of acceleration. In addition, when the gradient of the road is large, the control device 3 sets a larger predetermined jump to increase the second target acceleration.

[0071] Multiple predetermined accelerations are obtained through various parameters as described above, but the control device 3 ultimately adopts the smallest predetermined acceleration among these multiple predetermined accelerations and sets the second target acceleration based on this predetermined acceleration, for example, setting the second target acceleration with the smallest change. This is to suppress unpleasant feelings to the driver caused by large accelerations, and adverse situations caused by second target accelerations with large changes in amount or rate of change. Basically, the control device 3 determines the slope of the second target acceleration, in particular, based on such predetermined accelerations.

[0072] Next, after step S15, the control device 3 proceeds to step S16 to determine whether the second target acceleration has reached the predetermined acceleration Ac1. As a result, if the control device 3 determines that the second target acceleration has reached the predetermined acceleration Ac1 (step S16: Yes), it proceeds to step S17; otherwise, if it does not determine that the second target acceleration has reached the predetermined acceleration Ac1 (step S16: No), it returns to step S15. In the latter case, the control device 3 continues acceleration control based on the second target acceleration set in step S15 until the second target acceleration reaches the predetermined acceleration Ac1.

[0073] Next, in step S17, the control device 3 ends the process of increasing the second target acceleration at a rate greater than that of the first target acceleration, and sets the second acceleration such that it changes at the same rate (slope) as the first target acceleration while maintaining the difference between the second target acceleration and the first target acceleration. Based on this second target acceleration, the control device 3 controls the torque of the drive source 1. Then, the control device 3 proceeds to step S18.

[0074] Next, in step S18, the control device 3 determines whether the absolute value of the reduction rate (%) of dapsfil reaches or exceeds a predetermined value, that is, whether the state changes from an increasing rate of change of throttle opening to a state of decreasing or exceeding a predetermined value. As a result, if the control device 3 determines that the absolute value of the reduction rate of dapsfil reaches or exceeds the predetermined value (step S18: Yes), it proceeds to step S19; otherwise, if it does not determine that the absolute value of the reduction rate of dapsfil reaches or exceeds the predetermined value (step S18: No), it returns to step S17. In the latter case, the control device 3 continues acceleration control based on the second target acceleration set in step S17 until the absolute value of the reduction rate of dapsfil reaches or exceeds the predetermined value.

[0075] Next, after step S19, control device 3 adjusts the second target acceleration to gradually converge to the first target acceleration, and controls the torque of drive source 1 based on the second target acceleration. First, in step S19, control device 3 determines the convergence speed for converging the second target acceleration to the first target acceleration based on the rate of change of the first target acceleration and the throttle opening (operation speed of the accelerator pedal). Specifically, control device 3 establishes a control mapping diagram corresponding to the rate of change of the first target acceleration and the throttle opening, specifying the convergence speed, and determines the convergence speed corresponding to the current first target acceleration and the current rate of change of the throttle opening.

[0076] Here, refer to Figure 5 The control mapping diagram for the convergence speed based on an embodiment of the present invention will be explained. The convergence speed in the control mapping diagram is defined by establishing a correspondence between the rate of change of throttle opening (horizontal axis) and the first target acceleration (vertical axis). Specifically, the control mapping diagram includes four regions R1 to R4 defined by the rate of change of throttle opening and the first target acceleration, and a convergence speed value (represented as an absolute value) to be applied is set for each of these regions R1 to R4. In this case, a convergence speed value is set for each of regions R1 to R4. Furthermore, in Figure 5 The standard specifies that the rate of change of throttle opening, represented by the horizontal axis, is divided by the center of the horizontal axis (rate of change 0), with positive values ​​on the right (indicating the accelerator pedal is being depressed) and negative values ​​on the left (indicating the accelerator pedal is being released). Furthermore, the first target acceleration, represented by the vertical axis, is defined as increasing above the center of the vertical axis (where the first target acceleration is constant) and decreasing below it.

[0077] Region R1 is the region where the rate of change of throttle opening is negative (i.e., the region where the throttle opening decreases, or in other words, the region where the accelerator pedal is released). In region R1, a larger convergence speed is set to allow the second target acceleration to quickly return to the first target acceleration, consistent with the situation where the accelerator pedal is released. Conversely, region R2 is the region where the rate of change of throttle opening is approximately zero (i.e., the region where the throttle opening is almost constant, or in other words, the region where the accelerator pedal position is almost fixed). In region R2, a smaller convergence speed is set to allow the second target acceleration to slowly return to the first target acceleration, consistent with the situation where the accelerator pedal is almost not operated. Furthermore, a rate of change of throttle opening of approximately zero means that the absolute value of this rate of change is less than a predetermined value close to zero.

[0078] Furthermore, region R3 is a region where the rate of change of throttle opening is positive and the first target acceleration decreases. In region R3, a larger convergence rate is set to ensure that the second target acceleration quickly returns to the first target acceleration in accordance with the decrease in the first target acceleration. Conversely, region R4 is a region where the rate of change of throttle opening is positive and the first target acceleration increases. In region R4, a smaller convergence rate is set to ensure that the second target acceleration slowly returns to the first target acceleration in accordance with the increase in the first target acceleration.

[0079] Next, the relationship between the convergence speeds set in each region R1 to R4 will be explained. First, the convergence speed set in region R1 is greater than the convergence speeds set in other regions R2 to R4. Therefore, when the rate of change of throttle opening is negative, a larger convergence speed is set compared to when the rate of change of throttle opening is 0 or higher. Furthermore, the convergence speed set in region R3 is greater than the convergence speed set in region R4. Regions R3 and R4 are divided based on whether the first target acceleration decreases or increases (in addition, regions R1 and R2 are not defined together based on the first target acceleration). Therefore, based on the relationship between these regions R3 and R4, it can be said that a larger convergence speed is set when the first target acceleration decreases compared to when the first target acceleration increases.

[0080] Furthermore, the convergence rate set in region R3 is greater than the convergence rate set in region R2. Therefore, when the rate of change of throttle opening is positive and the first target acceleration decreases, a larger convergence rate is set compared to the case where the rate of change of throttle opening is approximately zero. Conversely, the convergence rate set in region R4 is less than the convergence rate set in region R2. Therefore, when the rate of change of throttle opening is positive and the first target acceleration increases, a smaller convergence rate is set compared to the case where the rate of change of throttle opening is approximately zero.

[0081] Furthermore, in the example above, a control mapping diagram was shown where a convergence speed value was set for each of regions R1 to R4. However, in other examples, multiple convergence speed values ​​that change continuously or in stages according to the rate of change of throttle opening and the magnitude of the first target acceleration can also be set in each of regions R1 to R4. In this case, the smaller the rate of change of throttle opening, the larger the convergence speed is set; conversely, the more significantly the first target acceleration decreases, the larger the convergence speed is set (in other words, the more significantly the first target acceleration increases, the smaller the convergence speed is set).

[0082] return Figure 4After step S19, control device 3 proceeds to step S20, sets a second target acceleration based on the convergence speed determined in step S19, and controls the torque of drive source 1 based on this second target acceleration. Then, control device 3 proceeds to step S21, determining whether the second target acceleration has reached the first target acceleration, i.e., determining whether the convergence of the second target acceleration to the first target acceleration is complete. As a result, if control device 3 determines that the second target acceleration has reached the first target acceleration (step S21: Yes), it proceeds to step S22. In this case, control device 3 ends acceleration control based on the second target acceleration and begins acceleration control based on the first target acceleration (step S22). Then, control device 3 ends... Figure 4 The process is as shown in the flowchart. In contrast, if the control device 3 does not determine that the second target acceleration has reached the first target acceleration (step S21: No), it returns to step S19. In this case, the control device 3 continues to determine the convergence speed until the second target acceleration reaches the first target acceleration, and performs acceleration control based on the second target acceleration set by the convergence speed.

[0083] [Functions and Effects]

[0084] Next, the function and effect of the vehicle control system and control method based on this embodiment will be explained.

[0085] In this embodiment, the control device 3 includes a first control and a second control. The first control sets a first target acceleration that increases according to the increase of the throttle opening, and controls the torque of the drive source 1 based on the set first target acceleration. The second control sets a second target acceleration that increases at a rate greater than the rate of change of the first target acceleration, so that the jump of the vehicle 20 increases within a range less than a predetermined jump, and controls the torque of the drive source 1 based on the set second target acceleration. When the rate of change of the throttle opening increases by a predetermined value or more in a state where the vehicle 20 is not accelerating (stable driving state), the second control is performed first. The first control is performed after the second target acceleration set in the second control reaches the predetermined acceleration Ac1.

[0086] According to this embodiment, when the acceleration of vehicle 20 begins, acceleration control (second control) is performed based on a second target acceleration that causes the acceleration of vehicle 20 to increase within a range less than a predetermined acceleration. Therefore, excessive acceleration can be suppressed, and the acceleration can rapidly increase to reach the predetermined acceleration Ac1. This suppresses driver discomfort caused by excessive acceleration and improves acceleration responsiveness. As a result, the driver's driving experience at the start of acceleration is improved.

[0087] Furthermore, in this embodiment, the control device 3 sets a predetermined jump for setting the second target acceleration based on at least one of the following: the rate of increase in throttle opening, vehicle speed, gear stages of the transmission, the rate of change of the first target acceleration, and the gradient of the road on which the vehicle 20 travels. By setting the second target acceleration based on such a predetermined jump, it is possible to suppress unpleasant sensations to the driver caused by large jumps, and adverse situations caused by large changes in the amount or rate of change of the second target acceleration.

[0088] Furthermore, in this embodiment, the acceleration Ac1 is defined as the minimum acceleration that a person can perceive as the start of acceleration (e.g., 0.27–0.3 m / s²). 2 The acceleration is set within a certain range. By using acceleration control (second control) based on the second target acceleration mentioned above, the acceleration is quickly brought to such a specified acceleration Ac1, i.e., the minimum perceived acceleration, so that the driver can perceive the acceleration of the vehicle 20 as early as possible at the start of acceleration, which can effectively improve acceleration responsiveness.

[0089] Furthermore, in this embodiment, even if the rate of change of the throttle opening increases by a predetermined value or more when the vehicle 20 is not accelerating (stable driving state), the control device 3 will not perform the second control but will perform the first control when the rate of increase of the throttle opening is greater than the predetermined value. Thus, for example, when throttle operation is performed due to unexpected foot vibration caused by the impact of the vehicle 20 crossing a step, large acceleration caused by the second control can be prevented.

[0090] Furthermore, in this embodiment, even if the rate of change of the throttle opening increases by a predetermined value when the vehicle 20 is not accelerating, the control device 3 will not perform the second control but the first control when the throttle opening increases from the state where the vehicle 20 is stationary. This prevents the so-called throttle jerking phenomenon caused by transmission gap engagement from occurring during the start-up from a stationary state due to the large acceleration generated by the second control.

[0091] Furthermore, in this embodiment, the rate of change of the throttle opening is increased by a predetermined value, which is an increase of 1% or more. Therefore, it is possible to control the acceleration of the vehicle 20 to a certain extent after confirming the driver's intention to operate the accelerator pedal and their acceleration intention.

[0092] [Variation Example]

[0093] Thus, the above-described embodiments are examples for illustrating the present invention, and the present invention is not limited to these embodiments. The present invention can be implemented in various ways without departing from its spirit.

Claims

1. A control system of a vehicle characterized by comprising: has: a drive source that generates a driving force of a vehicle; an accelerator opening degree sensor that detects an accelerator opening degree, which is an opening degree of an accelerator pedal possessed by the vehicle; and a control device that is configured to control the drive source based on the accelerator opening degree detected by the accelerator opening degree sensor, the control device is configured to be able to perform: first control that sets a target acceleration that increases in accordance with an increase in the accelerator opening degree and controls a torque of the drive source based on the set target acceleration, second control that sets a target acceleration that increases at a rate of change that is greater than a rate of change of the target acceleration applied in the first control so that a jerk of the vehicle increases in a range that is less than a prescribed jerk and controls a torque of the drive source based on the set target acceleration, when a rate of change of the accelerator opening degree increases by a prescribed value or more in a state in which the vehicle is not accelerating, the second control is performed first, and the first control is performed after the target acceleration set in the second control reaches a prescribed acceleration.

2. The control system of the vehicle according to claim 1, characterized in that the control device is configured to set the target acceleration applied in the second control based on at least any one or more of a rate of increase of the accelerator opening degree, a speed of the vehicle, a gear stage of a transmission possessed by the vehicle, a rate of change of the target acceleration applied in the first control, and a gradient of a travel road of the vehicle.

3. The control system of the vehicle according to claim 1 or 2, characterized in that the prescribed acceleration is prescribed based on a minimum acceleration at which a person can recognize that acceleration has started.

4. The control system of the vehicle according to claim 3, characterized in that The prescribed acceleration is an acceleration in the range of 0.27 to 0.3 m / s 2 .

5. The control system of the vehicle according to claim 1 or 2, characterized in that the control device is configured to, even when the rate of change of the accelerator opening degree increases by the prescribed value or more in the state in which the vehicle is not accelerating, not perform the second control but perform the first control when the rate of increase of the accelerator opening degree is a prescribed value or more.

6. The control system of the vehicle according to claim 1 or 2, characterized in that the control device is configured to, even when the rate of change of the accelerator opening degree increases by the prescribed value or more in the state in which the vehicle is not accelerating, not perform the second control but perform the first control when the accelerator opening degree increases from a state in which the vehicle is stopped.

7. The control system of the vehicle according to claim 1 or 2, characterized in that when the rate of change of the accelerator opening degree increases by the prescribed value or more is when the rate of change of the accelerator opening degree increases by 1% or more.

8. A control method of a vehicle, which is executed by a control device in a vehicle having a drive source that generates a driving force of the vehicle, a throttle opening sensor that detects a throttle opening, which is an opening of an accelerator pedal possessed by the vehicle, and the control device that is configured to control the drive source based on the throttle opening detected by the throttle opening sensor, characterized by, has: a drive source that generates a driving force of a vehicle; an accelerator opening degree sensor that detects an accelerator opening degree, which is an opening degree of an accelerator pedal possessed by the vehicle; and a control device that is configured to control the drive source based on the accelerator opening degree detected by the accelerator opening degree sensor, the control device is configured to be able to perform: first control that sets a target acceleration that increases in accordance with an increase in the accelerator opening degree and controls a torque of the drive source based on the set target acceleration, second control that sets a target acceleration that increases at a rate of change that is greater than a rate of change of the target acceleration applied in the first control so that a jerk of the vehicle increases in a range that is less than a prescribed jerk and controls a torque of the drive source based on the set target acceleration, when a rate of change of the accelerator opening degree increases by a prescribed value or more in a state in which the vehicle is not accelerating, the second control is performed first, and the first control is performed after the target acceleration set in the second control reaches a prescribed acceleration. performing second control that sets a target acceleration that increases at a rate of change greater than the target acceleration applied in the first control, to increase the jerk of the vehicle within a range that is less than a prescribed jerk, and controls the torque of the drive source based on the set target acceleration; and when the rate of change of the accelerator opening increases by more than a prescribed value in a state in which the vehicle is not accelerating, first performing the second control, and performing the first control after the target acceleration set in the second control reaches a prescribed acceleration.

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