Vehicle control system

Abstract

In a vehicle control system that controls the drive source based on a target acceleration, the aim is to improve the feeling of acceleration while ensuring controllability of acceleration in response to accelerator pedal operation. [Solution] The vehicle control system 1 includes a motor 2 that generates driving force for the vehicle, an accelerator opening sensor 16 that detects the accelerator opening, a vehicle speed sensor 18 that detects the vehicle speed, and a control device 20 configured to determine a target acceleration based on at least the accelerator opening and vehicle speed, and to control the motor 2 so that a driving force corresponding to the target acceleration is generated. The control device 20 is configured to determine a target jerk based on the target acceleration or the actual acceleration of the vehicle at the time the accelerator opening becomes constant, or the current vehicle speed, when the accelerator opening is constant during vehicle acceleration, and to determine the target acceleration so that the target jerk is achieved.

Description

[Technical Field]

[0001] The present invention relates to a vehicle control system that determines a target acceleration of a vehicle and controls a drive source based on the target acceleration. [Background Art]

[0002] This type of technology is described, for example, in Patent Document 1. Patent Document 1 describes a technology that sets a target acceleration based on a change in acceleration demand according to the operation state of an accelerator pedal, calculates a requested acceleration based on the acceleration demand, vehicle speed, and target acceleration, and operates an internal combustion engine to achieve the requested acceleration. This technology aims to allow a driver to experience a sense of sustained acceleration. [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2009-166717 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] Conventionally, a target acceleration of a vehicle is mainly determined based on the vehicle speed of the vehicle and an accelerator opening degree (an operation amount of an accelerator pedal), and a drive source is controlled based on the target acceleration. Specifically, since the larger the accelerator opening degree, the greater the driver's acceleration demand, a target acceleration having a larger value is determined. Further, the higher the vehicle speed, a target acceleration having a smaller value is determined. This is because, due to the characteristics of the drive source, when the vehicle speed increases (in this case, the rotation speed of the drive source increases), the output of the drive source tends to decrease.

[0005] Furthermore, the acceleration gain, which indicates the change in acceleration in response to changes in accelerator opening at each vehicle speed, is reduced relatively significantly as the vehicle speed increases. This is done to ensure controllability of acceleration in response to accelerator operation at each vehicle speed. However, when the acceleration gain is set in this way to ensure controllability, when the accelerator opening becomes constant during acceleration, the acceleration may decrease relatively significantly, impairing the feeling of sustained acceleration, or in other words, giving the driver a sense of stalling. This is because the target acceleration decreases as the vehicle speed increases. In other words, when the accelerator opening becomes constant, the target acceleration is determined according to the magnitude of the vehicle speed because the accelerator opening is fixed, and this target acceleration determined according to the vehicle speed becomes relatively small.

[0006] Here, in order to improve the feeling of sustained acceleration when the accelerator opening becomes constant during acceleration, it would be reasonable to set the target acceleration, which is determined according to the vehicle speed, to a relatively large value, that is, to suppress the degree of decrease in acceleration gain as the vehicle speed increases. However, if this is done, the change in target acceleration in response to changes in accelerator opening at each vehicle speed becomes too large, that is, the change in acceleration in response to accelerator opening becomes overly sensitive, and the controllability of acceleration in response to accelerator operation is not ensured. From the above, it can be said that it is difficult to achieve both controllability of acceleration in response to accelerator operation and the feeling of sustained acceleration when the accelerator opening becomes constant during acceleration.

[0007] This invention was made to solve the problems of the prior art described above, and aims to improve the feeling of acceleration while ensuring controllability of acceleration in response to accelerator operation in a vehicle control system that controls the drive source based on target acceleration. [Means for solving the problem]

[0008] 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 amount of operation of the vehicle's accelerator pedal; a vehicle speed sensor that detects the vehicle's speed; and a control device configured to determine a target acceleration based on at least the accelerator opening and vehicle speed, and to control the drive source so that a driving force corresponding to the target acceleration is generated. The control device is configured such that, when the accelerator opening is constant during vehicle acceleration, it determines a target jerk based on the target acceleration at the time the accelerator opening becomes constant or the actual acceleration of the vehicle, determines a target acceleration such that the target jerk is achieved, and determines a target jerk with a larger value the larger the target acceleration or actual acceleration at the time the accelerator opening becomes constant.

[0009] In the present invention configured as described above, the control device basically determines the target acceleration based on the accelerator opening and vehicle speed. However, when the accelerator opening is constant during vehicle acceleration, instead of using such a target acceleration, the control device determines the target jerk based on the target acceleration at the point when the accelerator opening becomes constant or the actual acceleration, and determines the target acceleration so that the target jerk is achieved. This ensures controllability of acceleration in response to accelerator operation while improving the feeling of acceleration extension when the accelerator opening becomes constant during acceleration. In particular, in this invention, the control device determines a target jerk that has a larger value the larger the target acceleration at the point when the accelerator opening becomes constant. As a result, when the target acceleration at the point when the accelerator opening becomes constant is large, it is assumed that the driver has a clear intention to accelerate, and a relatively large target jerk can be used to suppress the decrease in target acceleration. Therefore, the feeling of acceleration when the accelerator opening is constant can be effectively improved.

[0010] In another aspect of the present invention, a vehicle control system comprises: a drive source that generates driving force for the vehicle; an accelerator opening sensor that detects the accelerator opening, which is the amount of operation of the vehicle's accelerator pedal; a vehicle speed sensor that detects the vehicle's speed; and a control device configured to determine a target acceleration based on at least the accelerator opening and vehicle speed, and to control the drive source so that a driving force corresponding to the target acceleration is generated, wherein the control device is configured to determine a target jerk based on the current vehicle speed when the accelerator opening is constant during vehicle acceleration, to determine a target acceleration so that the target jerk is achieved, and to determine a target jerk with a larger value the higher the current vehicle speed. With the present invention configured in this way, it is possible to improve the feeling of acceleration when the accelerator opening becomes constant during acceleration, while ensuring controllability of acceleration in response to accelerator operation. In particular, in the present invention, the control device determines a target jerk that has a larger value the higher the current vehicle speed. As a result, when the vehicle speed is high when the accelerator opening is constant, the driver is pressing down on the accelerator pedal, so a smooth acceleration is required, and a relatively large target jerk can be used to suppress the decrease in target acceleration. Therefore, the feeling of acceleration when the accelerator opening is constant can be effectively improved.

[0011] In yet another aspect of the present invention, a vehicle control system comprises: a drive source that generates driving force for the vehicle; an accelerator opening sensor that detects the accelerator opening, which is the amount of operation of the vehicle's accelerator pedal; a vehicle speed sensor that detects the vehicle's speed; and a control device configured to determine a target acceleration based on at least the accelerator opening and the vehicle speed, and to control the drive source so that a driving force corresponding to the target acceleration is generated, wherein the control device is configured to determine a target jerk based on the target acceleration or the actual acceleration of the vehicle at the time the accelerator opening becomes constant and the current vehicle speed when the accelerator opening is constant during vehicle acceleration, and to determine the target acceleration so that the target jerk is achieved. With the present invention configured in this way, it is possible to improve the feeling of acceleration while ensuring controllability of acceleration in response to accelerator operation.

[0012] In the present invention, preferably, the control device is configured to determine a negative value for the jerk as the target jerk. According to the present invention configured in this way, when the accelerator opening is constant during vehicle acceleration, the degree of decrease in the target acceleration (rate of change during decrease) can be controlled using a target jerk with a negative value.

[0013] In the present invention, preferably, the control device is configured to determine a target acceleration such that, when the accelerator opening is not constant during vehicle acceleration, the target acceleration becomes larger as the accelerator opening is larger and smaller as the vehicle speed is higher. According to the present invention configured in this way, when the accelerator opening is changing, it is possible to determine an appropriate target acceleration corresponding to the accelerator opening and vehicle speed.

[0014] In the present invention, preferably, the control device is configured to determine a target jerk based on the rate of change of the accelerator opening when the accelerator opening is not constant during vehicle acceleration, and to correct the target acceleration based on the target jerk. According to the present invention configured in this way, when the accelerator opening is changing, the target acceleration can be smoothly changed in accordance with the rate of change in the accelerator opening. [Effects of the Invention]

[0015] According to the present invention, in a vehicle control system that controls the drive source based on a target acceleration, it is possible to improve the feeling of acceleration extension when the accelerator opening becomes constant during acceleration, while ensuring the controllability of acceleration in response to accelerator operation. [Brief explanation of the drawing]

[0016] [Figure 1]It is a schematic configuration diagram of a vehicle control system according to an embodiment of the present invention. [Figure 2] It is a block diagram showing the electrical configuration of a vehicle control system according to an embodiment of the present invention. [Figure 3] It schematically shows a target acceleration map according to an embodiment of the present invention. [Figure 4] It shows an example of the relationship between an accelerator opening degree defined by the target acceleration map according to an embodiment of the present invention and a target acceleration. [Figure 5] It shows an example of the relationship between a vehicle speed defined by the target acceleration map according to an embodiment of the present invention and a target acceleration. [Figure 6] It shows two examples of acceleration gain at each vehicle speed based on the target acceleration map according to an embodiment of the present invention. [Figure 7] It is a time chart for the two examples shown in Fig. 6 in the case where the accelerator opening degree becomes constant during acceleration. [Figure 8] It schematically shows a target jerk map according to an embodiment of the present invention. [Figure 9] It is an explanatory diagram of target acceleration determined by the target jerk map according to an embodiment of the present invention. [Figure 10] It is a flowchart showing control according to an embodiment of the present invention. [Figure 11] In an embodiment of the present invention, it is an explanatory diagram about correction of target acceleration based on jerk according to accelerator opening change speed. [Figure 12] It is a time chart for explaining an example of operations and effects achieved by a vehicle control system according to an embodiment of the present invention. [Figure 13] It is a time chart for explaining another example of operations and effects achieved by a vehicle control system according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, a vehicle control system according to an embodiment of the present invention will be described with reference to the accompanying drawings.

[0018] <System Configuration> First, the configuration of the vehicle control system according to this embodiment will be described with reference to Figures 1 and 2. Figure 1 is a schematic diagram showing the configuration of the vehicle control system according to this embodiment, and Figure 2 is a block diagram showing the electrical configuration of the vehicle control system according to this embodiment.

[0019] As shown in Figure 1, the vehicle control system 1 mainly comprises a motor 2 as a power source that generates driving force (torque) to drive the vehicle (electric vehicle), a battery 3 that supplies power to the motor 2, a reduction gear 4 that transmits the driving force of the motor 2 at a predetermined reduction ratio, a drive shaft 6 to which the driving force is transmitted from the reduction gear 4, and wheels (drive wheels) 8 driven by the driving force from the drive shaft 6. Note that instead of using a motor 2 as the driving source for the vehicle, an internal combustion engine or the like may be used.

[0020] Furthermore, the vehicle control system 1 includes an inverter 12 connected to the motor 2 and a control device 20 electrically connected to the inverter 12. The inverter 12 converts the DC power supplied from the battery 3 into AC power and supplies it to the motor 2, and converts the regenerative power generated from the motor 2 into DC power and supplies it to the battery 3, thereby charging the battery 3.

[0021] As shown in Figure 2, the control device 20 is composed of circuits and is a controller based on a well-known microcomputer. The control device 20 includes one or more processors 20a as a central processing unit (CPU) for executing programs, a memory 20b for storing programs and data, which is composed of, for example, RAM (Random Access Memory) or ROM (Read Only Memory), and an input / output bus for inputting and outputting electrical signals. For example, the control device 20 is composed of an ECU (Electronic Control Unit).

[0022] The control device 20 receives signals from the accelerator pedal position sensor 16 and the vehicle speed sensor 18, and outputs a control signal to the inverter 12 for controlling the motor 2 based on these signals (Figures 1 and 2). The accelerator pedal position sensor 16 detects the accelerator pedal position, which is the amount of accelerator pedal operation by the driver, and the vehicle speed sensor 18 detects the vehicle speed. In this embodiment, the control device 20 determines a target acceleration based on the accelerator pedal position and vehicle speed detected by the accelerator pedal position sensor 16 and the vehicle speed sensor 18, and controls the motor 2 via the inverter 12 so that a driving force corresponding to this target acceleration is generated.

[0023] <Control details> Next, the control content performed by the control device 20 in this embodiment will be described in detail.

[0024] (Target acceleration map) First, with reference to Figures 3 to 5, the contents related to the target acceleration map used in this embodiment will be explained. Figure 3 schematically shows the target acceleration map used in this embodiment, Figure 4 shows an example of the relationship between accelerator opening (horizontal axis) and target acceleration (vertical axis) as defined in the target acceleration map according to this embodiment, and Figure 5 shows an example of the relationship between vehicle speed (horizontal axis) and target acceleration (vertical axis) as defined in the target acceleration map according to this embodiment.

[0025] As shown in Figure 3, the target acceleration map is defined based on the accelerator opening (lateral direction) and vehicle speed (longitudinal direction). In this embodiment, the control device 20 stores such a target acceleration map in advance, and by referring to the target acceleration map, determines the target acceleration corresponding to the current accelerator opening and vehicle speed, and controls the motor 2 so that this target acceleration is achieved.

[0026] Specifically, the target acceleration map is designed so that a larger accelerator opening corresponds to a larger target acceleration value because the driver's acceleration request is greater (see arrow A1 in Figure 3 and Figure 4). Furthermore, the target acceleration map is designed so that a smaller target acceleration value corresponds to a higher vehicle speed (see arrow A2 in Figure 3 and Figure 5). This is because the output of motor 2 tends to decrease as vehicle speed and motor rotational speed increase.

[0027] Next, with reference to Figures 6 and 7, the problems associated with using the target acceleration map described above will be explained. Figure 6 shows an example of the acceleration gain (a value proportional to acceleration) that indicates the change in acceleration in response to changes in accelerator opening at each vehicle speed, as defined by the target acceleration map described above. In particular, Figure 6 shows the acceleration gain at each vehicle speed for two examples of target acceleration maps (the first example and the second example). The first example is shown as a white bar graph, and the second example is shown as a black bar graph. As shown in Figure 6, the first example shows a much larger decrease in acceleration gain as the vehicle speed increases compared to the second example. In other words, the second example suppresses the degree of decrease in acceleration gain with increasing vehicle speed compared to the first example.

[0028] Figure 7 is an example of a time chart showing, from top to bottom, vehicle speed, accelerator pedal position, and acceleration (target acceleration). Here, it shows the time change of each parameter when the accelerator pedal position becomes constant during acceleration. In Figure 7, the solid line shows the results from the first example in Figure 6, and the dashed line shows the results from the second example in Figure 6. These results show that the decrease in acceleration after the accelerator pedal position becomes constant is greater in the first example than in the second example. Specifically, in the first example, the acceleration decreases significantly after the accelerator pedal position becomes constant (arrow A11), which impairs the feeling of sustained acceleration, or in other words, gives the driver a feeling of stalling. In contrast, in the second example, the decrease in acceleration after the accelerator pedal position becomes constant is relatively small (arrow A12), so the feeling of sustained acceleration is maintained.

[0029] This result occurred because, in the first example, the acceleration gain was significantly reduced as the vehicle speed increased (Figure 6). In other words, when the accelerator opening is constant, the target acceleration is determined according to the magnitude of the vehicle speed because the accelerator opening is fixed. Therefore, in the first example, this target acceleration determined according to the vehicle speed is relatively small. In contrast, in the second example, the degree to which the acceleration gain decreases with increasing vehicle speed is suppressed (Figure 6), so the target acceleration determined according to the vehicle speed is relatively large.

[0030] However, in the second example, the change in target acceleration in response to changes in accelerator opening at each vehicle speed becomes too large; in other words, the acceleration change in response to accelerator opening becomes overly sensitive, and controllability of acceleration in response to accelerator operation is not ensured. In contrast, in the first example, the change in target acceleration in response to changes in accelerator opening at each vehicle speed is appropriate, so controllability of acceleration in response to accelerator operation is ensured.

[0031] Based on the above, it can be said that with the target acceleration map described above, it is difficult to achieve both controllability of acceleration in response to accelerator input and a sense of sustained acceleration when the accelerator opening becomes constant during acceleration.

[0032] (Target jerk map) In this embodiment, in order to solve the problems related to the target acceleration map described above, and in particular to achieve both controllability of acceleration in response to accelerator operation and a sense of sustained acceleration when the accelerator opening becomes constant during acceleration, the target acceleration is determined using a target jerk map defined separately from the target acceleration map.

[0033] Figure 8 schematically shows the target jerk map used in this embodiment. The target jerk map is defined based on acceleration (lateral direction), specifically the target acceleration when the accelerator opening becomes constant, and vehicle speed (longitudinal direction), specifically the current vehicle speed. In this embodiment, the control device 20 stores such a target jerk map in advance, and when the accelerator opening is constant during vehicle acceleration, it refers to the target jerk map to determine the target jerk based on the target acceleration when the accelerator opening becomes constant (this target acceleration is used continuously) and the current vehicle speed which changes moment by moment, and then determines the target acceleration so that this target jerk is achieved.

[0034] Specifically, the target jerk map specifies a negative value for the target jerk. This is because, when the accelerator opening remains constant during acceleration, the acceleration basically changes in the direction of decreasing, meaning the rate of change of acceleration (jerk) becomes negative.

[0035] Furthermore, the target jerk map is designed so that the larger the target acceleration at a constant accelerator opening, the larger the target jerk value (in other words, a negative value close to zero) is determined. As a result, when the target acceleration at a constant accelerator opening is large, a relatively large target acceleration is determined, and the decrease in target acceleration is suppressed. This is because when the target acceleration at a constant accelerator opening is large, the driver has a clear intention to accelerate, and therefore a smooth acceleration is required.

[0036] Furthermore, the target jerk map is designed so that the higher the current vehicle speed, the larger the target jerk value (in other words, a negative value close to zero) is determined. This means that when the current vehicle speed is high, a relatively large target acceleration is determined, and the decrease in target acceleration is suppressed. This is because when the current vehicle speed is high, the driver is pressing the accelerator pedal harder than when the current speed is low, so a smoother acceleration is required.

[0037] Next, with reference to Figure 9, the target acceleration determined by the target jerk map described above will be explained in detail. Figure 9 is an example of a time chart showing, from top to bottom, vehicle speed, accelerator opening, acceleration (target acceleration), and target jerk. First, at time t1, the accelerator opening becomes constant during acceleration. Up to time t1, when the accelerator opening is changing, the control device 20 determines the target acceleration from the target acceleration map based on the current accelerator opening and vehicle speed. However, after time t1, when the accelerator opening becomes constant, the control device 20 determines the target jerk from the target jerk map based on the target acceleration at the time the accelerator opening becomes constant and the current vehicle speed, and then determines the target acceleration based on this target jerk.

[0038] Specifically, as shown by the arrow in Figure 9, the control device 20 sequentially determines the target jerk from the target jerk map based on the target acceleration at time t1 and the constantly changing vehicle speed (see reference numeral A21). Then, the control device 20 determines the target acceleration to achieve this target jerk from the target jerk determined in this sequential manner (see reference numeral A22). For example, the control device 20 repeatedly determines the target jerk and target acceleration at a predetermined period, and determines the target acceleration for the current time by applying (adding) the target jerk (negative value) determined this time to the target acceleration determined last time.

[0039] The target jerk defined in the target jerk map is set to allow for predictability of the jerk change during constant acceleration. In other words, the target jerk is set to allow the driver to predict the jerk change so that they can recognize the time to reach the target and maintain their balance against the inertial force acting on the vehicle. In this case, the so-called tau theory, defined by the scalar quantity "τ(x)=x / x'" which has units of time, is used (the "'" represents differentiation; the same applies hereafter). The tau theory is a theory based on the idea that humans perceive the world as a predicted time (τ) until the gap to the target becomes zero, and control themselves accordingly. In this embodiment, we consider controlling actions to keep "τ'(x)" constant when trying to make the gap zero. This is "τ'(x)=C=1-(xx'' / x' 2This is an example where "x'' = (1-C)(x' 2 This is expressed as "τ'(x) = -0.5". For example, the change in jerk is minimized when "τ'(x) = -0.5". In the embodiment described above, the target jerk was determined from a pre-stored target jerk map, but in other examples, the target jerk may be determined by calculating the formula given here without using a target jerk map.

[0040] Furthermore, in the above-described embodiment, the target jerk was determined based on the target acceleration at the point when the accelerator opening became constant. However, instead of the target acceleration, the target jerk may be determined based on the actual acceleration of the vehicle at the point when the accelerator opening becomes constant (which uniquely corresponds to the target acceleration).

[0041] (flowchart) Next, with reference to Figure 10, a flowchart illustrating the control according to this embodiment will be described. This flowchart is repeatedly executed by the control device 20 at predetermined intervals. Specifically, the processor 20a within the control device 20 reads a program stored in the memory 20b and executes the program, thereby realizing the control related to this flowchart.

[0042] First, in step S11, the control device 20 acquires various information from the vehicle's control system 1. Specifically, the control device 20 acquires the accelerator opening detected by the accelerator opening sensor 16 and the vehicle speed detected by the vehicle speed sensor 18.

[0043] Next, in step S12, the control device 20 refers to a pre-stored target acceleration map (Figure 3) and determines a target acceleration corresponding to the accelerator opening and vehicle speed acquired in step S11.

[0044] Next, in step S13, the control device 20 determines whether or not the accelerator opening has changed. If the control device 20 determines that the accelerator opening has changed (step S13: Yes), that is, if the accelerator opening is not constant, the system proceeds to step S14.

[0045] In step S14, the control device 20 determines the rate of change of the accelerator opening (accelerator opening change rate) from the accelerator opening and corrects the target acceleration determined in step S12 based on the jerk corresponding to the accelerator opening change rate. Here, with reference to Figure 11, the correction of the target acceleration based on the jerk corresponding to the accelerator opening change rate (accelerator operation rate) will be explained. In Figure 11, the solid line shows the target acceleration determined in step S12, and the dashed line shows the target acceleration corrected based on the jerk. In this embodiment, the control device 20 determines the jerk to be generated in the vehicle based on the accelerator opening change rate, and uses this jerk to make a correction to smooth the change in the target acceleration determined in step S12. Specifically, the control device 20 determines a larger jerk value the larger the accelerator opening change rate. After correcting the target acceleration in step S14, the control device 20 controls the motor 2 via the inverter 12 so that a driving force corresponding to this target acceleration is generated.

[0046] Returning to Figure 10, if the control device 20 does not determine in step S13 that the accelerator opening has changed (step S13: No), that is, if the accelerator opening is constant, it proceeds to step S15. In step S15, instead of using the target acceleration determined in step S12, the control device 20 determines a target jerk based on the target acceleration at the point when the accelerator opening becomes constant and the current vehicle speed, and re-determines the target acceleration so that this target jerk is achieved. Specifically, the control device 20 refers to a pre-stored target jerk map (Figure 8) to determine the target jerk corresponding to the target acceleration at the point when the accelerator opening becomes constant and the current vehicle speed. After re-determining the target acceleration in step S15, the control device 20 controls the motor 2 via the inverter 12 so that a driving force corresponding to this target acceleration is generated.

[0047] <Mechanism and Effects> Next, the operation and effects of the vehicle control system 1 according to this embodiment will be described with reference to Figures 12 and 13.

[0048] Figure 12 is a time chart illustrating an example of the operation and effect of the vehicle control system 1 according to this embodiment. From top to bottom, Figure 12 shows the time changes of accelerator opening, vehicle speed, and acceleration (target acceleration) when the accelerator opening becomes constant during acceleration. In Figure 12, the solid line shows an example where the target acceleration at time t2 when the accelerator opening becomes constant is relatively large (see reference numeral A31), and the dashed line shows an example where the target acceleration at time t2 when the accelerator opening becomes constant is relatively small (see reference numeral A32). In these examples, the vehicle speed at time t2 when the accelerator opening becomes constant is assumed to be the same.

[0049] As shown by the solid line in Figure 12, according to this embodiment, when the target acceleration at point t2, when the accelerator opening becomes constant, is large (see reference numeral A31), a relatively large target jerk (a negative value close to 0) is determined, thereby determining a relatively large target acceleration. As a result, when the accelerator opening is constant during acceleration, the decrease in target acceleration is suppressed, and a feeling of sustained acceleration is ensured. Thus, according to this embodiment, when the target acceleration at point t2, when the accelerator opening becomes constant, is large, it is assumed that the driver has a clear intention to accelerate, and by using a relatively large target jerk to suppress the decrease in target acceleration, the feeling of sustained acceleration when the accelerator opening is constant can be improved.

[0050] In contrast, as shown by the dashed line in Figure 12, according to this embodiment, when the target acceleration at point t2, when the accelerator opening becomes constant, is small (see reference numeral A32), a relatively small target jerk is determined, resulting in a relatively small target acceleration. As a result, when the accelerator opening is constant during acceleration, the target acceleration is reduced relatively significantly, and the extension of acceleration is suppressed. When the target acceleration at point t2, when the accelerator opening becomes constant, is small, it is likely that the driver is controlling the distance between vehicles and vehicle speed in urban areas, and a smooth extension of acceleration is not particularly necessary (conversely, if the acceleration is too smooth, it becomes difficult to control the distance between vehicles and vehicle speed). Therefore, according to this embodiment, when the target acceleration at point t2, when the accelerator opening becomes constant, is small, a smooth extension of acceleration is not necessary, and the target acceleration is reduced by using a relatively small target jerk, thereby suppressing the extension of acceleration when the accelerator opening is constant.

[0051] Next, Figure 13 is a time chart illustrating another example of the operation and effect of the vehicle control system 1 according to this embodiment. From top to bottom, Figure 13 shows the time changes of accelerator opening, vehicle speed, and acceleration (target acceleration) when the accelerator opening becomes constant during acceleration. In Figure 13, the solid line shows an example where the vehicle speed is relatively high when the accelerator opening is constant (see reference numeral A41), and the dashed line shows an example where the vehicle speed is relatively low when the accelerator opening is constant (see reference numeral A42). In these examples, the target acceleration at time t3 when the accelerator opening becomes constant is assumed to be the same.

[0052] As shown by the solid line in Figure 13, according to this embodiment, when the vehicle speed is high while the accelerator opening is constant (see reference numeral A41), a relatively large target jerk (a negative value close to 0) is determined, which in turn determines a relatively large target acceleration. As a result, when the accelerator opening is constant during acceleration, the decrease in target acceleration is suppressed, and a feeling of smooth acceleration is ensured. When the vehicle speed is high while the accelerator opening is constant, the driver is pressing down on the accelerator pedal (see reference numeral A51), so smooth acceleration is necessary. Therefore, according to this embodiment, when the vehicle speed is high while the accelerator opening is constant, smooth acceleration is necessary, and by using a relatively large target jerk to suppress the decrease in target acceleration, the feeling of smooth acceleration when the accelerator opening is constant can be improved.

[0053] In contrast, as shown by the dashed line in Figure 13, according to this embodiment, when the vehicle speed is low while the accelerator opening is constant (see reference numeral A42), a relatively small target jerk is determined, which in turn determines a relatively small target acceleration. As a result, when the accelerator opening is constant during acceleration, the target acceleration is reduced relatively significantly, and the extension of acceleration is suppressed. When the vehicle speed is low while the accelerator opening is constant, the driver is not pressing the accelerator pedal very hard (see reference numeral A52), so a smooth extension of acceleration is not particularly necessary. Therefore, according to this embodiment, when the vehicle speed is low while the accelerator opening is constant, a smooth extension of acceleration is not necessary, and the target acceleration is reduced by using a relatively small target jerk, thereby suppressing the extension of acceleration when the accelerator opening is constant.

[0054] As described above, according to the vehicle control system 1 of this embodiment, the control device 20 basically determines the target acceleration based on the accelerator opening and vehicle speed. However, when the accelerator opening is constant during vehicle acceleration, instead of using such a target acceleration, the control device 20 determines the target jerk based on the target acceleration at the point when the accelerator opening becomes constant and the current vehicle speed, and determines the target acceleration so that the target jerk is achieved. This makes it possible to improve the feeling of acceleration extension when the accelerator opening becomes constant during acceleration while ensuring controllability of acceleration in response to accelerator operation.

[0055] In particular, according to this embodiment, when the accelerator opening is constant during vehicle acceleration, the control device 20 determines a target jerk with a larger value the greater the target acceleration at the point when the accelerator opening becomes constant. As a result, when the target acceleration at the point when the accelerator opening becomes constant is large, it is assumed that the driver has a clear intention to accelerate, and a relatively large target jerk can be used to suppress the decrease in target acceleration. Therefore, the feeling of acceleration when the accelerator opening is constant can be effectively improved.

[0056] Furthermore, according to this embodiment, when the accelerator opening is constant during vehicle acceleration, the control device 20 determines a target jerk that has a larger value the higher the current vehicle speed. As a result, when the vehicle speed is high while the accelerator opening is constant, the driver is pressing down on the accelerator pedal, and therefore a smooth acceleration is required. This allows for the suppression of a decrease in the target acceleration by using a relatively large target jerk. Thus, the feeling of smooth acceleration when the accelerator opening is constant can be effectively improved.

[0057] Furthermore, according to this embodiment, the control device 20 determines a negative value for the target jerk. This makes it possible to control the degree of decrease in the target acceleration (rate of change during decrease) using a negative value for the target jerk when the accelerator opening is constant during vehicle acceleration.

[0058] Furthermore, according to this embodiment, when the accelerator opening is not constant during vehicle acceleration, the control device 20 can determine a target acceleration such that the value increases as the accelerator opening increases and decreases as the vehicle speed increases. As a result, when the accelerator opening is changing, an appropriate target acceleration can be determined according to the accelerator opening and vehicle speed.

[0059] Furthermore, according to this embodiment, when the accelerator opening is not constant during vehicle acceleration, the control device 20 determines a target jerk based on the accelerator opening change rate and corrects the target acceleration based on the target jerk. As a result, when the accelerator opening is changing, the target acceleration can be smoothly changed in accordance with the accelerator opening change rate. [Explanation of Symbols]

[0060] 1. Vehicle control system 2 motors 3 Batteries 12 Inverters 16. Accelerator position sensor 18. Vehicle speed sensor 20 Control device

Claims

1. A vehicle control system, A drive source that generates the driving force of the vehicle, An accelerator position sensor detects the accelerator position, which is the amount the accelerator pedal of the vehicle is operated. A vehicle speed sensor for detecting the vehicle speed of the aforementioned vehicle, A control device configured to determine a target acceleration based at least on the accelerator opening and the vehicle speed, and to control the drive source so that a driving force corresponding to the target acceleration is generated, It has, The control device is When the accelerator opening is constant during the acceleration of the vehicle, the target jerk is determined based on the target acceleration or the actual acceleration of the vehicle at the time the accelerator opening becomes constant, and the target acceleration is determined so that the target jerk is achieved. The larger the target acceleration or the actual acceleration at the point when the accelerator opening becomes constant, the larger the value of the target jerk is determined. A vehicle control system characterized by being configured in such a way.

2. A vehicle control system, A drive source that generates the driving force of the vehicle, An accelerator position sensor detects the accelerator position, which is the amount the accelerator pedal of the vehicle is operated. A vehicle speed sensor for detecting the vehicle speed of the aforementioned vehicle, A control device configured to determine a target acceleration based at least on the accelerator opening and the vehicle speed, and to control the drive source so that a driving force corresponding to the target acceleration is generated, It has, The control device is When the vehicle is accelerating and the accelerator opening is constant, the target jerk is determined based on the current vehicle speed, and the target acceleration is determined so that the target jerk is achieved. The higher the current vehicle speed, the larger the value of the target jerk that is determined. A vehicle control system characterized by being configured in such a way.

3. A vehicle control system, A drive source that generates the driving force of the vehicle, An accelerator position sensor detects the accelerator position, which is the amount the accelerator pedal of the vehicle is operated. A vehicle speed sensor for detecting the vehicle speed of the aforementioned vehicle, A control device configured to determine a target acceleration based at least on the accelerator opening and the vehicle speed, and to control the drive source so that a driving force corresponding to the target acceleration is generated, It has, The control device is configured to determine a target jerk based on the target acceleration or the actual acceleration of the vehicle at the time the accelerator opening becomes constant, and the current vehicle speed, when the accelerator opening is constant during the acceleration of the vehicle, and to determine the target acceleration so that the target jerk is achieved. A vehicle control system characterized by the following features.

4. The vehicle control system according to any one of claims 1 to 3, wherein the control device is configured to determine a negative value for the target jerk.

5. The vehicle control system according to any one of claims 1 to 3, wherein the control device is configured to determine the target acceleration such that, when the accelerator opening is not constant during acceleration of the vehicle, the value increases as the accelerator opening increases and decreases as the vehicle speed increases.

6. The vehicle control system according to claim 5, wherein the control device is configured to determine a target jerk based on the rate of change of the accelerator opening when the accelerator opening is not constant during acceleration of the vehicle, and to correct the target acceleration based on the target jerk.

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