Vehicle control system and control method

Abstract

The target acceleration is set to accurately improve the acceleration response at the start of vehicle acceleration. [Solution] The vehicle control system 10 includes a drive source 1, an accelerator opening sensor 5 for detecting the accelerator opening, and a control device 3 for controlling the drive source 1. The control device 3 includes a first control which sets a first target acceleration that increases in accordance with the increase in accelerator opening and controls the torque of the drive source based on the first target acceleration, and a second control which sets a second target acceleration that increases at a larger rate of change than the first target acceleration applied in the first control in order to increase the jerk of the vehicle 20 within a range less than a predetermined jerk, and controls the torque of the drive source based on the second target acceleration. When the rate of change of the accelerator opening increases by more than a predetermined value while the vehicle 20 is not accelerating, the second control is performed first, and the first control is performed after the second target acceleration set in the second control reaches a predetermined acceleration Ac1.

Description

Technical Field

[0001] The present invention relates to a vehicle control system and a control method that set a target acceleration and control the torque of a drive source based on the target acceleration.

Background Art

[0002] Conventionally, there has been known a technique of setting a target acceleration based on a driver's accelerator operation or the like and controlling the torque of a drive source such as an engine or a motor so that the target acceleration is achieved. For example, Patent Document 1 describes a technique of setting a target acceleration so as to generate a maximum jerk at an accelerator opening increased by 5 to 10% from the accelerator opening in a steady running state. Further, for example, Patent Document 2 describes a technique of obtaining a target value of jerk (acceleration) and setting a target acceleration based on this target value.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] As a result of intensive studies by the inventors of the present case, it has been found that at the start of vehicle acceleration (when the driver starts stepping on the accelerator pedal), the driver may not be able to recognize the acceleration because the acceleration of the vehicle is small and may feel that the acceleration responsiveness is poor. In particular, when the acceleration of the vehicle is the minimum acceleration that a human can recognize as the start of acceleration (for example, 0.27 to 0.3 m / s 2It was found that drivers cannot perceive acceleration when the acceleration is below a certain level, which will be referred to as the "minimum perceptual acceleration" below. When the vehicle's acceleration remains below this minimum perceptual acceleration for an extended period, drivers tend to perceive poor acceleration responsiveness.

[0005] Therefore, in order to improve acceleration responsiveness at the start of acceleration, it is desirable to set the target acceleration so that the vehicle's acceleration increases rapidly in order to shorten the time during which the vehicle's acceleration is below the minimum perceptible acceleration. In this case, it is thought that the target acceleration should be set so that the vehicle's jerk is large. However, if the jerk is made too large, it may cause discomfort to the driver. Furthermore, the technologies described in the aforementioned Patent Documents 1 and 2 were insufficient to accurately improve acceleration responsiveness at the start of acceleration.

[0006] The present invention was made to solve the problems of the prior art described above, and aims to provide a vehicle control system and control method that can set a target acceleration to accurately improve the acceleration response at the start of vehicle acceleration. [Means for solving the problem]

[0007] To achieve the above objective, the present invention provides a vehicle control system comprising: a drive source that generates driving force for the vehicle; an accelerator opening sensor that detects the accelerator opening, which is the opening degree of the accelerator pedal of the vehicle; and a control device configured to control the drive source based on the accelerator opening detected by the accelerator opening sensor. The control device includes a first control that sets a target acceleration that increases in accordance with the increase in accelerator opening and controls the torque of the drive source based on the set target acceleration; a second control that sets a target acceleration that increases at a larger rate of change than the target acceleration applied in the first control in order to increase the vehicle's jerk within a range less than a predetermined jerk and controls the torque of the drive source based on the set target acceleration; and is configured to first perform the second control when the rate of change of the accelerator opening increases by more than a predetermined value while the vehicle is not accelerating, and then perform the first control after the target acceleration set in the second control reaches a predetermined acceleration.

[0008] With the present invention configured as described above, at the start of vehicle acceleration, acceleration control (second control) is initially performed based on a target acceleration that increases the vehicle's jerk within a range below a predetermined jerk. This suppresses the occurrence of excessive jerk, allowing acceleration to be quickly built up and reach the predetermined acceleration. As a result, acceleration responsiveness can be improved while suppressing discomfort to the driver caused by excessive jerk. Consequently, the driver's driving feel at the start of acceleration can be improved.

[0009] In the present invention, preferably, the control device is configured to set a predetermined jerk used 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 the accelerator opening, the vehicle speed, the gear position 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 the vehicle travels on. By setting the target acceleration to be applied in the second control based on such a predetermined jerk, it is possible to suppress discomfort caused to the driver by a large jerk, as well as malfunctions that occur due to a large target acceleration in terms of change amount or rate of change.

[0010] In the present invention, preferably, the predetermined acceleration is defined based on the minimum acceleration at which a human being can perceive the start of acceleration. The second control described above allows the acceleration to quickly reach a predetermined acceleration, i.e., the minimum perceptible acceleration, thereby enabling the driver to recognize the vehicle's acceleration early at the start of acceleration, and effectively improving acceleration responsiveness.

[0011] In a preferred example of the present invention, the predetermined acceleration is 0.27 to 0.3 m / s². 2 This is acceleration within the specified range.

[0012] In the present invention, preferably, the control device is configured to perform the first control without performing the second control when the rate of change of the accelerator opening increases by more than a predetermined value while the vehicle is not accelerating, provided that the rate of increase of the accelerator opening is greater than or equal to the predetermined value. With the present invention configured in this way, for example, when the accelerator is operated due to unintentional vibrations of the foot caused by the impact when the vehicle goes over a bump, the second control can prevent a large acceleration from occurring.

[0013] In the present invention, preferably, the control device is configured to perform the first control without performing the second control when the accelerator opening increases from a stationary state, even if the rate of change of the accelerator opening increases by more than a predetermined value when the vehicle is not accelerating. With the present invention configured in this way, a large acceleration is generated by the second control when the vehicle starts moving from a stop, which prevents the occurrence of so-called tip-in shocks, for example, caused by play in the transmission.

[0014] In the present invention, preferably, when the rate of change of the accelerator opening increases by a predetermined value or more, it means when the rate of change of the accelerator opening increases by 1% or more. With the present invention configured in this way, acceleration control can be performed on the vehicle after the driver's intention to operate the accelerator pedal and their intention to accelerate have been confirmed to some extent.

[0015] In other words, the present invention relates to a vehicle having a drive source that generates driving force for the vehicle, an accelerator opening sensor that detects the accelerator opening, which is the opening of the accelerator pedal of the vehicle, and a control device configured to control the drive source based on the accelerator opening detected by the accelerator opening sensor, and is characterized by comprising: a step of performing a first control in which a target acceleration that increases in accordance with an increase in the accelerator opening is set and the torque of the drive source is controlled based on the set target acceleration; a step of performing a second control in which a target acceleration that increases at a larger rate of change than the target acceleration applied in the first control is set in order to increase the jerk of the vehicle within a range less than a predetermined jerk is set and the torque of the drive source is controlled based on the set target acceleration; and a step of first performing the second control when the rate of change of the accelerator opening increases by a predetermined value or more while the vehicle is not accelerating, and then performing the first control after the target acceleration set in the second control reaches the predetermined acceleration. [Effects of the Invention]

[0016] According to the vehicle control system and control method of the present invention, the target acceleration can be set to accurately improve the acceleration responsiveness at the start of acceleration of the vehicle. [Brief explanation of the drawing]

[0017] [Figure 1] This is a schematic diagram of a vehicle to which a vehicle control system according to an embodiment of the present invention is applied. [Figure 2] This is an explanatory diagram of basic acceleration control using a first target acceleration according to an embodiment of the present invention. [Figure 3] This is an explanatory diagram of acceleration control using a second target acceleration according to an embodiment of the present invention. [Figure 4] This flowchart shows acceleration control according to an embodiment of the present invention. [Figure 5] Shows the convergence speed control map according to an embodiment of the present invention.

Embodiments for Carrying Out the Invention

[0018] Hereinafter, a vehicle control system and a control method according to an embodiment of the present invention will be described with reference to the accompanying drawings.

[0019] [Overall Configuration] First, referring to FIG. 1, the overall configuration of the vehicle control system according to the present embodiment will be described. FIG. 1 is a schematic configuration diagram of a vehicle to which the vehicle control system according to the present embodiment is applied.

[0020] As shown in FIG. 1, the vehicle 20 includes a drive source 1 that generates a driving force of the vehicle 20, such as an engine (internal combustion engine) or an electric motor, a control device 3 configured to control the drive source 1, an accelerator opening sensor 5 that detects the accelerator opening, which is the opening of an accelerator pedal (not shown) of the vehicle 20, a vehicle speed sensor 7 that detects the speed (vehicle speed) of the vehicle 20, and an acceleration sensor 9 that detects the acceleration of the vehicle 20. A vehicle control system 10 having these components is mounted on the vehicle 20. In addition to these sensors 5, 7, and 9, the vehicle 20 is provided with various other sensors (for example, when the vehicle 20 has a transmission, a gear position sensor that detects the gear position set in this transmission).

[0021] The control device 3 is composed of a computer including one or more processors 3a (typically a CPU), and a memory 3b such as a ROM and a RAM that stores various programs (including basic control programs such as an OS and application programs that are launched on the OS and realize specific functions) and various data that are interpreted and executed on the processor 3a.

[0022] In this embodiment, the control device 3 sets a target acceleration that the vehicle should generate based on the accelerator opening detected by the accelerator opening sensor 5 and the vehicle speed detected by the vehicle speed sensor 7, and controls the torque of the drive source 1 so that the target acceleration is achieved. Details of the control performed by this control device 3 will be described later.

[0023] [Control Method] Next, with reference to Figures 2 and 3, the control method performed by the control device 3 in this embodiment will be described.

[0024] First, the basic acceleration control in this embodiment will be explained with reference to Figure 2. In Figure 2, graph G11 shows the change in accelerator opening over time, and graph G12 shows the change in the basic (base) first target acceleration set according to this accelerator opening over time.

[0025] As shown in Figure 2, at time t11, while the vehicle 20 is in steady-state driving, the driver begins to press the accelerator pedal, increasing the accelerator opening (wherein "steady-state driving" means when the vehicle speed is greater than 0 and there is no acceleration (the same applies hereinafter), and basically the first target acceleration is set to 0). In particular, at time t11, the rate of change in the accelerator opening increases by 1% or more. From this time t11, the control device 3 sets a first target acceleration that increases in accordance with the increase in the accelerator opening, and controls the torque of the drive source 1 so that this first target acceleration is achieved. In this case, the control device 3 sets the first target acceleration according to the vehicle speed and the gear stage of the transmission of the vehicle 20, in addition to the accelerator opening. For example, the first target acceleration may be set by the method described in Patent Document 1 above.

[0026] Incidentally, as mentioned above, when the acceleration of the vehicle 20 begins (when the driver starts pressing the accelerator pedal), if the acceleration of the vehicle 20 is small, the driver cannot perceive the acceleration. More specifically, when the target acceleration is less than a predetermined acceleration Ac1, the driver cannot perceive the acceleration. This predetermined acceleration Ac1 corresponds to the minimum acceleration at which a human can perceive the start of acceleration (minimum perceptible acceleration), for example, 0.27 to 0.3 m / s². 2 This is acceleration within the specified range.

[0027] In this case, if the vehicle 20 is accelerated based on the first target acceleration as shown in graph G12 of Figure 2, the first target acceleration will be less than the predetermined acceleration Ac1 during the period T11 from time t11 to time t12 at the start of acceleration, so the driver will not perceive the acceleration. If this period T11 is long, the driver tends to feel that the acceleration response is poor.

[0028] Therefore, in this embodiment, in order to improve acceleration responsiveness at the start of acceleration, the acceleration of the vehicle 20 is increased rapidly in order to shorten the time during which the acceleration of the vehicle 20 is less than a predetermined acceleration Ac1. For this purpose, in this embodiment, the control device 3 sets a second target acceleration that increases at a larger rate of change (slope) than the first target acceleration at the start of acceleration. In this case, the control device 3 sets the second target acceleration so as to increase the jerk (acceleration rate) of the vehicle 20 within a range that does not cause discomfort to the driver, specifically so as to increase the jerk of the vehicle 20 within a range less than a predetermined jerk.

[0029] Next, with reference to Figure 3, acceleration control using the second target acceleration according to this embodiment will be described. In Figure 3, graph G21 shows the change in accelerator opening over time, graph G22 shows the change in the rate of change of accelerator opening over time, graph G23 shows the change in the first target acceleration over time, graph G24 shows the change in the second target acceleration over time, and graph G25 shows the change in the jerk of the vehicle 20 (corresponding to the target jerk over time).

[0030] As shown in Figure 3, at time t21, during steady-state driving of the vehicle 20 (period T21), the driver begins to press the accelerator pedal, causing the rate of change in accelerator opening to increase by 1% or more (graph G21). From this time t21, the control device 3 sets a second target acceleration that increases at a larger rate of change (slope) than the first target acceleration (graph G24, arrow Ar1) in order to increase the jerk of the vehicle 20 within a range below a predetermined jerk (graph G25), and controls the torque of the drive source 1 based on this second target acceleration. When setting the second target acceleration in this way, the control device 3 also determines the first target acceleration in parallel (graph G23). However, at this point, the control device 3 performs acceleration control based on the second target acceleration (period T22), and does not use the first target acceleration when performing acceleration control.

[0031] More specifically, the control device 3 sets the predetermined jerk based on at least one of the following: the rate of increase in accelerator opening, vehicle speed, gear position of the transmission in the vehicle 20, the rate of change (slope) of the first target acceleration, and the gradient of the road the vehicle 20 travels on. The control device 3 then sets the second target acceleration so as to increase the jerk of the vehicle 20 within a range less than the predetermined jerk. For example, the control device 3 sets the second target acceleration so as to quickly increase the jerk of the vehicle 20 to the predetermined jerk and maintain this predetermined jerk.

[0032] Subsequently, at time t22, the second target acceleration reaches a predetermined acceleration Ac1. The predetermined acceleration Ac1 is set in advance based on the minimum perceived acceleration described above, for example, 0.27 to 0.3 m / s². 2 The acceleration is within this range. From time t22, the control device 3 stops increasing the second target acceleration at a larger rate of change than the first target acceleration, and sets the second target acceleration to change at the same rate of change (slope) as the first target acceleration while maintaining the difference between them, and controls the torque of the drive source 1 based on the second target acceleration.

[0033] Subsequently, at time t23, the rate of change in accelerator opening changes from an increasing state to a state where it decreases by more than a predetermined value; in other words, the rate of change in accelerator opening shifts from increasing to decreasing by more than a predetermined value (Graph G22). From time t23, the control device 3 adjusts the second target acceleration to gradually converge to the first target acceleration (arrow Ar2), and controls the torque of the drive source 1 based on this second target acceleration. By doing so, by converging the second target acceleration to the first target acceleration, the control device 3 prevents the driver from continuing to use the second target acceleration, which would result in acceleration exceeding the driver's expectations and make subsequent driving operations difficult. Specifically, the control device 3 determines the convergence speed to converge the second target acceleration to the first target acceleration based on the first target acceleration and the rate of change in accelerator opening (accelerator pedal operation speed), and adjusts the second target acceleration based on this convergence speed. More specifically, the control device 3 determines the convergence speed by referring to a control map in which the convergence speed is defined in correspondence with the rate of change in the first target acceleration and accelerator opening. This allows the second target acceleration to converge to the first target acceleration, so as not to cause any discomfort to the driver.

[0034] Then, at time t24, when the adjusted second target acceleration reaches the first target acceleration, that is, when the convergence of the second target acceleration to the first target acceleration is completed, the control device 3 terminates the acceleration control based on the second target acceleration and starts acceleration control based on the first target acceleration.

[0035] Furthermore, the control performed from time t21 to time t22 (period T22) corresponds to the "second control" in this invention, and the control performed from time t22 onward corresponds to the "first control" in this invention. The "first control" is basically acceleration control using the first target acceleration, but also includes acceleration control using the second target acceleration which is changed at the same rate of change (slope) as the first target acceleration, while the "second control" is acceleration control using the second target acceleration which is increased at a larger rate of change than the first target acceleration.

[0036] [Control Flow] Next, with reference to Figure 4, a flowchart illustrating acceleration control according to an embodiment of the present invention will be described. This flowchart is repeatedly executed by the control device 3 at a predetermined cycle. Specifically, the processor 3a within the control device 3 reads a program stored in memory 3b and executes the program, thereby realizing the control related to this flowchart.

[0037] First, in step S10, the control device 3 acquires various information, including detected values ​​from at least the accelerator opening sensor 5, the vehicle speed sensor 7, and the acceleration sensor 9. The control device 3 also calculates the average value of the detected value from the accelerator opening sensor 5 over a 30ms period (corresponding to the accelerator opening, hereinafter referred to as "apsfil"), calculates the slope of this apsfil over a 100ms period (corresponding to the change in accelerator opening, hereinafter referred to as "dapsfil"), and calculates the slope of this dapsfil over a 1s period (hereinafter referred to as "ddapsfil").

[0038] Next, in step S11, the control device 3 determines whether the vehicle 20 is in a steady-state driving state. Specifically, the control device 3 determines that the vehicle 20 is in a steady-state driving state 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 target acceleration instead of detected acceleration) is 0 (step S11: Yes). In this case, the control device 3 proceeds to step S12.

[0039] In contrast, if the control device 3 does not determine that the vehicle 20 is in a steady-state driving state (step S11: No), for example, if the vehicle 20 is stopped or is already accelerating, it does not proceed to step S12. In particular, in this embodiment, when the vehicle 20 is accelerating from a stopped state, the control device 3 does not perform acceleration control based on the second target acceleration (in this case, it performs acceleration control based on the first target acceleration). This is because if the acceleration is greatly increased from a stopped state by acceleration control based on the second target acceleration, so-called tip-in shocks caused by the backlash of the transmission may occur.

[0040] Next, in step S12, the control device 3 determines whether the dapsfil is equal to or greater than a predetermined value. Here, the control device 3 uses dapsfil to determine whether the rate of change in the accelerator opening has increased by 1% or more. By making this determination, the control device 3 ensures that acceleration control is performed on the vehicle 20 only after confirming to some extent the driver's intention to operate the accelerator pedal. If, as a result of step S12, the control device 3 determines that dapsfil is equal to or greater than a predetermined value (step S12: Yes), it proceeds to step S13. On the other hand, if the control device 3 does not determine that dapsfil is equal to or greater than a predetermined value (step S12: No), that is, if dapsfil is less than a predetermined value, it returns to step S12 and does not proceed to step S13.

[0041] Next, in step S13, the control device 3 determines whether dapsfil has updated its maximum value and whether ddapsfil is below a predetermined value. Here, first, it determines whether the sequentially obtained dapsfil (which fluctuates relatively greatly) has updated its maximum value to confirm the driver's intention to accelerate (acceleration request). Also, by determining whether ddapsfil is below a predetermined value, it confirms whether accelerator operation is being performed due to unintentional foot vibrations caused by impacts such as when the vehicle 20 goes over a bump. In such a situation, a large acceleration should not be generated in the vehicle 20, so acceleration control based on the second target acceleration is not performed (in this case, acceleration control based on the first target acceleration is performed).

[0042] If, as a result of step S13, the control device 3 determines that dapsfil has updated its maximum value and ddapsfil is not below a predetermined value (step S13: No), it proceeds to step S14, sets a first target acceleration, and controls the torque of the drive source 1 so that this first target acceleration is achieved. In this case, the control device 3 sets the first target acceleration according to the accelerator opening, vehicle speed, transmission gear, etc. For example, the control device 3 may set the first target acceleration by the method described in Patent Document 1 above.

[0043] In response to this, if, as a result of step S13, the control device 3 determines that dapsfil has updated its maximum value and ddapsfil is less than a predetermined value (step S13: Yes), it proceeds to step S15, sets a second target acceleration, and controls the torque of the drive source 1 so that this second target acceleration is achieved. Specifically, the control device 3 sets a predetermined jerk based on ddapsfil (corresponding to the rate of increase in accelerator opening), vehicle speed, transmission gear, rate of change (slope) of the first target acceleration, and the gradient of the road the vehicle 20 travels on, and sets a second target acceleration that increases at a larger rate of change than the first target acceleration in order to increase the jerk of the vehicle 20 within a range less than this predetermined jerk (typically, the second target acceleration is set so that the jerk of the vehicle 20 is quickly increased to a predetermined jerk and maintained at this predetermined jerk).

[0044] Here, we will illustrate the specific method for setting the second target acceleration by the control device 3 (in particular, the method for setting the predetermined jerk for setting the second target acceleration). First, when ddapsfil is large, the control device 3 sets a relatively large predetermined jerk in order to significantly increase the second target acceleration. In this case, the control device 3 should use the maximum value of ddapsfil in order to accurately judge the degree of the driver's intention to accelerate. Furthermore, when the vehicle speed is low (around 10-30 km / h) and high (60 km / h or more), the control device 3 sets a relatively small predetermined jerk so as not to widen the difference between the second target acceleration and the first target acceleration. On the other hand, when the vehicle speed is medium (around 30-60 km / h), the control device 3 sets a relatively large predetermined jerk in order to significantly increase the second target acceleration. Also, when the gear is in a low gear (for example, 1st gear), the control device 3 sets a relatively small predetermined jerk in order to suppress shocks. Furthermore, when the rate of change (slope) of the first target acceleration is small, a relatively small predetermined jerk is set. This is because if the rate of change of the second target acceleration is increased when the rate of change of the first target acceleration is small, the rate of change of the second target acceleration will suddenly decrease when the stage of changing the second target acceleration using the rate of change (slope) of the first target acceleration begins (see time t22, period T23 in Figure 3), and the continuity of acceleration will be lost. In addition, when the gradient of the travel path is large, the control device 3 sets a relatively large predetermined jerk in order to increase the second target acceleration.

[0045] As described above, multiple predetermined jerks can be obtained using various parameters. Ultimately, the control device 3 adopts the smallest predetermined jerk among the obtained multiple predetermined jerks and sets the second target acceleration based on this predetermined jerk, for example, setting the second target acceleration that results in the smallest change. This is to suppress discomfort caused to the driver by a large jerk and malfunctions caused by a second target acceleration with a large change or rate of change. Basically, the control device 3 determines the slope of the second target acceleration in particular based on such predetermined jerks.

[0046] Next, after step S15 described above, the control device 3 proceeds to step S16 to determine whether the second target acceleration has reached the predetermined acceleration Ac1. 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. 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.

[0047] Next, in step S17, the control device 3 finishes increasing the second target acceleration at a larger rate of change than the first target acceleration, and sets the second target acceleration to change at the same rate of change (slope) as the first target acceleration while maintaining the difference between them, and controls the torque of the drive source 1 based on the second target acceleration. Then, the control device 3 proceeds to step S18.

[0048] Next, in step S18, the control device 3 determines whether the absolute value of the dapsfil decrease rate (%) has become greater than or equal to a predetermined value, that is, whether the rate of change of the accelerator opening has decreased by a predetermined value or more from a state in which it was increasing. As a result, if the control device 3 determines that the absolute value of the dapsfil decrease rate has become greater than or equal to a predetermined value (step S18: Yes), it proceeds to step S19. If it does not determine that the absolute value of the dapsfil decrease rate has become greater than or equal to a 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 dapsfil decrease rate becomes greater than or equal to a predetermined value.

[0049] Next, in step S19 and beyond, the control device 3 adjusts the second target acceleration to gradually converge to the first target acceleration, and controls the torque of the drive source 1 based on this second target acceleration. First, in step S19, the control device 3 determines the convergence speed to converge the second target acceleration to the first target acceleration based on the rate of change of the first target acceleration and the accelerator opening (the operating speed of the accelerator pedal). Specifically, the control device 3 refers to a control map in which the convergence speed is defined in correspondence with the rate of change of the first target acceleration and the accelerator opening, and determines the convergence speed corresponding to the current rate of change of the first target acceleration and the current rate of change of the accelerator opening.

[0050] Here, with reference to Figure 5, a control map of the convergence speed according to an embodiment of the present invention will be described. The control map defines the convergence speed in correspondence with the rate of change of accelerator opening (horizontal axis) and the first target acceleration (vertical axis). Specifically, the control map includes four regions R1 to R4 defined by the rate of change of accelerator opening and the first target acceleration, and a convergence speed value (meaning an absolute value) to be applied is set for each of these regions R1 to R4. In this case, one convergence speed value is set for each region R1 to R4. In Figure 5, the rate of change of accelerator opening shown on the horizontal axis is defined to be positive on the right side (indicating that the accelerator pedal is depressed) and negative on the left side (indicating that the accelerator pedal is released), with the center of the horizontal axis (rate of change of 0) as the boundary. The first target acceleration shown on the vertical axis is defined to increase on the upper side and decrease on the lower side, with the center of the vertical axis (where the first target acceleration is constant) as the boundary.

[0051] Region R1 is the region where the rate of change of the accelerator pedal opening is negative (i.e., the region where the accelerator pedal opening is decreasing, or in other words, the region where the accelerator pedal is being released). In this region R1, a relatively large convergence speed is set to quickly return the second target acceleration to the first target acceleration, in accordance with the situation where the accelerator pedal is being released. Region R2 is the region where the rate of change of the accelerator pedal opening is approximately 0 (i.e., the region where the accelerator pedal opening is almost constant, or in other words, the region where the position of the accelerator pedal is almost fixed). In this region R2, a relatively small convergence speed is set to slowly return the second target acceleration to the first target acceleration, in accordance with the situation where the accelerator pedal is hardly being operated. Note that a rate of change of accelerator pedal opening of approximately 0 means that the absolute value of the rate of change is less than a predetermined value close to 0.

[0052] Furthermore, region R3 is a region where the rate of change of the accelerator opening is positive and the first target acceleration is decreasing. In region R3, a relatively large convergence speed is set to quickly return the second target acceleration to the first target acceleration, in accordance with the situation where the first target acceleration is decreasing. In region R4, a relatively small convergence speed is set to slowly return the second target acceleration to the first target acceleration, in accordance with the situation where the first target acceleration is increasing.

[0053] Next, we will explain the relative magnitudes of the convergence speeds set in each region R1 to R4. First, the convergence speed set in region R1 is greater than the convergence speeds set in the other regions R2 to R4. From this, it follows that when the rate of change of the accelerator opening is negative, a larger convergence speed is set than when the rate of change of the accelerator opening is 0 or greater. Also, the convergence speed set in region R3 is greater than the convergence speed set in region R4. Since regions R3 and R4 are divided based on whether the first target acceleration decreases or increases (note that regions R1 and R2 are not defined based on the first target acceleration), from the relationship between regions R3 and R4, it can be said that when the first target acceleration is decreasing, a larger convergence speed is set than when the first target acceleration is increasing.

[0054] Furthermore, the convergence speed set in region R3 is greater than the convergence speed set in region R2. This means that when the rate of change of the accelerator opening is positive and the first target acceleration is decreasing, a greater convergence speed is set than when the rate of change of the accelerator opening is approximately 0. Also, the convergence speed set in region R4 is smaller than the convergence speed set in region R2. This means that when the rate of change of the accelerator opening is positive and the first target acceleration is increasing, a smaller convergence speed is set than when the rate of change of the accelerator opening is approximately 0.

[0055] In the example above, a control map was shown in which one convergence velocity value was set for each region R1 to R4. However, in other examples, multiple convergence velocity values ​​may be set in each region R1 to R4, which change continuously or stepwise depending on the rate of change of the accelerator opening and the magnitude of the first target acceleration. In this case, it is preferable to set a larger convergence velocity as the rate of change of the accelerator opening decreases, and to set a larger convergence velocity as the first target acceleration decreases (in other words, to set a smaller convergence velocity as the first target acceleration increases).

[0056] Returning to Figure 4, after step S19, the control device 3 proceeds to step S20, where it sets a second target acceleration based on the convergence speed determined in step S19, and controls the torque of the drive source 1 based on this second target acceleration. Then, the control device 3 proceeds to step S21, where it determines whether the second target acceleration has reached the first target acceleration, that is, whether the convergence of the second target acceleration to the first target acceleration has been completed. If the 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, the control device 3 terminates the acceleration control based on the second target acceleration and starts acceleration control based on the first target acceleration (step S22). Then, the control device 3 terminates the process shown in the flow chart of Figure 4. On the other hand, 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 determines the convergence speed until the second target acceleration reaches the first target acceleration, and continues acceleration control based on the second target acceleration set from this convergence speed.

[0057] [Mechanism of Action and Effects] Next, the operation and effects of the vehicle control system and control method according to this embodiment will be described.

[0058] In this embodiment, the control device 3 includes a first control that sets a first target acceleration that increases in accordance with the increase in accelerator opening and controls the torque of the drive source 1 based on the set first target acceleration, and a second control that sets a second target acceleration that increases at a larger rate of change than the first target acceleration in order to increase the jerk of the vehicle 20 within a range less than a predetermined jerk, and controls the torque of the drive source 1 based on the set second target acceleration. When the vehicle 20 is not accelerating (steady-state driving), the second control is performed first when the rate of change of the accelerator opening increases by more than a predetermined value, and the first control is performed after the second target acceleration set in the second control reaches the predetermined acceleration Ac1.

[0059] According to this embodiment, when the vehicle 20 starts accelerating, acceleration control (second control) is performed based on a second target acceleration that increases the jerk of the vehicle 20 within a range less than a predetermined jerk. This suppresses the occurrence of excessive jerk and allows the acceleration to be quickly built up to reach the predetermined acceleration Ac1. As a result, it is possible to improve acceleration responsiveness while suppressing discomfort to the driver caused by excessive jerk. Consequently, it is possible to improve the driver's driving feeling at the start of acceleration.

[0060] Furthermore, in this embodiment, the control device 3 sets a predetermined jerk used to set the second target acceleration based on at least one of the following: the rate of increase in accelerator opening, vehicle speed, transmission gear, rate of change of the first target acceleration, and the gradient of the road the vehicle 20 travels on. By setting the second target acceleration based on such a predetermined jerk, it is possible to suppress discomfort to the driver caused by a large jerk, and malfunctions caused by a second target acceleration with a large change amount or rate of change.

[0061] Furthermore, in this embodiment, the predetermined acceleration Ac1 is the minimum acceleration that a human can perceive as the start of acceleration (for example, 0.27 to 0.3 m / s²). 2 It is set based on acceleration within a certain range. By using acceleration control (second control) based on the second target acceleration described above, the acceleration is quickly brought to this predetermined acceleration Ac1, that is, the minimum perceptible acceleration, which allows the driver to recognize the acceleration of the vehicle 20 early at the start of acceleration, and effectively improves acceleration responsiveness.

[0062] Furthermore, in this embodiment, even if the rate of change of the accelerator opening increases by more than a predetermined value when the vehicle 20 is not accelerating (steady-state driving), the control device 3 performs the first control without performing the second control if the rate of increase of the accelerator opening is more than the predetermined value. This prevents the generation of a large acceleration by the second control when, for example, the accelerator is operated due to unintentional vibration of the foot caused by the impact when the vehicle 20 goes over a bump.

[0063] Furthermore, in this embodiment, even if the rate of change of the accelerator opening increases by more than a predetermined value when the vehicle 20 is not accelerating, the control device 3 performs the first control without performing the second control when the accelerator opening increases from a stationary state. This prevents the occurrence of so-called tip-in shocks, such as those caused by play in the transmission, which would otherwise occur due to the second control generating a large acceleration when the vehicle 20 starts moving from a stop.

[0064] Furthermore, in this embodiment, the situation where the rate of change of the accelerator pedal opening increases by more than a predetermined value is defined as when the rate of change of the accelerator pedal opening increases by 1% or more. This allows acceleration control to be performed on the vehicle 20 only after the driver's intention to operate the accelerator pedal and their intention to accelerate have been confirmed to some extent.

[0065] [Differentiation] Thus, the embodiments described above are illustrative examples for explaining the present invention, and the present invention is not limited to these embodiments. The present invention can be implemented in various forms without departing from its spirit. [Explanation of Symbols]

[0066] 1. Power source 3. Control device 5. Accelerator position sensor 7. Vehicle speed sensor 9. Accelerometer 10. Vehicle control system 20 vehicles

Claims

1. A vehicle control system, A drive source that generates the driving force of the vehicle, An accelerator position sensor that detects the accelerator position, which is the degree of opening of the accelerator pedal of the vehicle, A control device configured to control the drive source based on the accelerator opening detected by the accelerator opening sensor, It has, The control device is The system includes a first control that sets a target acceleration that increases in accordance with the increase in the accelerator opening, and controls the torque of the drive source based on the set target acceleration. The system includes a second control that controls the torque of the drive source based on the set target acceleration, by setting a target acceleration that increases at a larger rate of change than the target acceleration applied in the first control, in order to increase the jerk of the vehicle within a range less than a predetermined jerk. When the vehicle is not accelerating and the rate of change of the accelerator opening increases by more than a predetermined value, the second control is performed first, and after the target acceleration set in the second control reaches the predetermined acceleration, the first control is performed. A vehicle control system characterized by being configured in such a way.

2. The vehicle control system according to claim 1, wherein the control device is configured to set a predetermined jerk used to set the target acceleration applied in the second control, based on at least one of the following: the rate of increase of the accelerator opening, the speed of the vehicle, the gear position 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 the vehicle travels on.

3. The vehicle control system according to claim 1 or 2, wherein the predetermined acceleration is defined based on the minimum acceleration at which a human being can perceive the start of acceleration.

4. The predetermined acceleration is 0.27 to 0.3 m / s². 2 The vehicle control system according to claim 3, wherein the acceleration is within the range.

5. The vehicle control system according to claim 1 or 2, wherein the control device is configured to perform the first control without performing the second control when the rate of change of the accelerator opening increases by more than or equal to the predetermined value while the vehicle is not accelerating, provided that the rate of increase of the accelerator opening is greater than or equal to the predetermined value.

6. The vehicle control system according to claim 1 or 2, wherein the control device is configured to perform the first control without performing the second control when the accelerator opening rate increases by more than the predetermined value while the vehicle is not accelerating, or when the accelerator opening increases from a stopped state.

7. The vehicle control system according to claim 1 or 2, wherein the rate of change of the accelerator opening increases by more than the predetermined value, means that the rate of change of the accelerator opening increases by 1% or more.

8. A vehicle having a drive source that generates driving force for the vehicle, an accelerator opening sensor that detects the accelerator opening, which is the opening degree of the accelerator pedal of the vehicle, and a control device configured to control the drive source based on the accelerator opening detected by the accelerator opening sensor, wherein a vehicle control method is performed by the control device, The first control step involves setting a target acceleration that increases in accordance with the increase in the accelerator opening, and controlling the torque of the drive source based on the set target acceleration. The process involves setting a target acceleration that increases at a larger rate of change than the target acceleration applied in the first control, in order to increase the jerk of the vehicle within a range less than a predetermined jerk, and performing a second control that controls the torque of the drive source based on the set target acceleration. When the vehicle is not accelerating, if the rate of change of the accelerator opening increases by more than a predetermined value, first perform the second control, and after the target acceleration set in the second control reaches the predetermined acceleration, perform the first control. A vehicle control method characterized by having the following:

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