Driving support device

Abstract

To make it possible to improve travel performance of a vehicle at off-road.SOLUTION: A driving support device 60 comprises, as function units: a storage unit 101 for storing an acceleration characteristic map MP1; a request derivation unit 103 for deriving, on the basis of the acceleration characteristic map MP1, acceleration DVS of a vehicle according to an accelerator opening AC, as requested acceleration DVSRq; and a command processing unit 105 for transmitting a command value based on the requested acceleration DVSRq to a driving device 20 and a braking device 30. When the requested acceleration DVSRq is included in an acceleration range RDVS, the command processing unit 105 derives command driving force FdTr and command braking force FbTr so as to satisfy conditions that the command driving force FdTr and the command braking force FbTr are both greater than 0 (zero), and that a difference between the command driving force FdTr and the command braking force FbTr has a value corresponding to the requested acceleration DVSRq.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a driving assistance device that assists a driver of a vehicle in driving the vehicle. [Background technology]

[0002] Patent Document 1 discloses an example of a traction control device that adjusts the braking force of wheels when a vehicle is traveling off-road. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-90886 Summary of the Invention [Problem to be solved by the invention]

[0004] Simultaneous operation, in which both the accelerator pedal and the brake pedal are operated simultaneously, is known as a driving technique for improving a vehicle's off-road performance. Simultaneous operation is a driving technique in which the driver operates the accelerator pedal with the right foot while operating the brake pedal with the left foot. By performing simultaneous operation, the driver can simultaneously adjust the vehicle's driving force and braking force. However, while skilled, advanced drivers can perform simultaneous operation when driving a vehicle off-road, it is difficult for drivers other than advanced drivers to perform simultaneous operation. [Means for solving the problem]

[0005] A driving assistance device for solving the above problem is applied to a vehicle including an operating member operated to adjust the acceleration of the vehicle, a drive unit that adjusts the driving force of the vehicle, and a brake unit that adjusts the braking force of the vehicle. The driving assistance device includes a storage unit that stores acceleration characteristics that indicate the relationship between the operating amount of the operating member and the acceleration of the vehicle, a demand derivation unit that derives the acceleration of the vehicle corresponding to the operating amount based on the acceleration characteristics, and a command processing unit that transmits command values ​​corresponding to the required acceleration to the driving unit and the brake unit. When the required acceleration is within a predetermined acceleration range, the command processing unit derives the driving force command value and the braking force command value so that both are greater than 0 (zero) and the difference between the driving force command value and the braking force command value is a value corresponding to the required acceleration. [Effects of the Invention]

[0006] The driving assistance device has the effect of improving the off-road driving performance of the vehicle. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic diagram showing the configuration of a vehicle equipped with a driving assistance device according to an embodiment. [Figure 2] FIG. 2 is a block diagram showing a functional configuration of the driving assistance device of FIG. [Figure 3] FIG. 3 is a flowchart showing a series of processes executed by the processing circuit of the driving assistance device of FIG. [Figure 4] FIG. 4 is a schematic diagram showing how a vehicle stopped on an uphill road is started to move. [Figure 5] FIG. 5 is a timing chart for starting a vehicle that has stopped on an uphill road. [Figure 6] FIG. 6 is a schematic diagram showing a state in which a vehicle is stopped on a downhill road. [Figure 7] FIG. 7 is a timing chart for stopping a vehicle on a downhill road. [Figure 8] FIG. 8 is a diagram showing a modified example of the acceleration characteristics map shown in FIG. [Figure 9] FIG. 9 is a diagram showing an example of an acceleration characteristics map in a case where the vehicle is equipped with an operation member dedicated to the acceleration / deceleration operation mode. DETAILED DESCRIPTION OF THE INVENTION

[0008] An embodiment of a driving assistance device will be described below with reference to FIGS. <Vehicle Overview> 1 shows an outline of a vehicle 10 equipped with a driving assistance device 60. The vehicle 10 is equipped with an accelerator pedal 11, a brake pedal 12, a drive device 20, a braking device 30, multiple types of sensors, and a switching operation unit 50.

[0009] The drive device 20 adjusts the drive force Fd of the vehicle 10. The drive device 20 includes a power unit 21 and a drive control unit 22 that controls the power unit 21. The power unit 21 has at least one of an engine and a drive motor. An example of the drive control unit 22 is an electronic control device. The drive control unit 22 controls the drive force Fd of the vehicle 10 by operating the power unit 21. The drive control unit 22 is also configured to be able to send and receive various information and commands to and from the driving assistance device 60 via an in-vehicle network.

[0010] The braking device 30 adjusts the braking force Fb of the vehicle 10. The braking device 30 includes a braking actuator 31 and a braking control unit 32 that controls the braking actuator 31. An example of the braking control unit 32 is an electronic control device. The braking control unit 32 controls the braking force Fb of the vehicle 10 by operating the braking actuator 31. The braking control unit 32 is also configured to be able to send and receive various information and commands to and from the driving assistance device 60 via an in-vehicle network.

[0011] <Sensor> The multiple sensors output detection signals according to the detection results to the driving assistance device 60. The vehicle 10 is equipped with, as sensors, an operation-related sensor that detects information related to the driver's operation, and a state quantity detection sensor that detects state quantities of the vehicle 10.

[0012] The vehicle 10 is equipped with an accelerator sensor 41 and a brake sensor 42 as operation-related sensors. The accelerator sensor 41 detects the amount of operation of the accelerator pedal 11 by the driver. The brake sensor 42 detects the amount of operation of the brake pedal 12 by the driver. The vehicle 10 may also be equipped with a sensor that detects the operating force of the brake pedal 12 by the driver or a correlation value thereof as a brake sensor. Hereinafter, the operation amount based on the detection signal of the accelerator sensor 41 will be referred to as "accelerator opening degree AC." The operation amount based on the detection signal of the brake sensor 42 will be referred to as "braking operation amount BP."

[0013] The vehicle 10 is equipped with a longitudinal acceleration sensor 44, a lateral acceleration sensor 45, and a wheel speed sensor 46 as state quantity detection sensors. The longitudinal acceleration sensor 44 detects the longitudinal acceleration of the vehicle 10. The lateral acceleration sensor 45 detects the lateral acceleration of the vehicle 10. A wheel speed sensor 46 is provided for each wheel of the vehicle 10. The wheel speed sensor 46 detects the rotational speed of the corresponding wheel. Hereinafter, the acceleration based on the detection signal of the longitudinal acceleration sensor 44 will be referred to as "longitudinal acceleration Gx." The acceleration based on the detection signal of the lateral acceleration sensor 45 will be referred to as "lateral acceleration Gy." The rotational speed based on the detection signal of the wheel speed sensor 46 will be referred to as "wheel speed VW."

[0014] <Switching operation section> The switching operation unit 50 is an operation unit that switches the operation mode of the vehicle 10. The vehicle 10 has two operation modes available: a normal operation mode and an acceleration / deceleration operation mode. When the normal operation mode is selected, the driving force Fd of the vehicle 10 is adjusted by operating the accelerator pedal 11, while the braking force Fb of the vehicle 10 is adjusted by operating the brake pedal 12. When the acceleration / deceleration operation mode is selected, both the driving force Fd and the braking force Fb of the vehicle 10 can be adjusted by operating the accelerator pedal 11. In other words, when the acceleration / deceleration operation mode is selected, the accelerator pedal 11 functions as an "operating member" that is operated to adjust the acceleration of the vehicle 10.

[0015] The normal operation mode or the acceleration / deceleration operation mode can be selected by an occupant of the vehicle 10, such as a driver, operating the switching operation unit 50. The switching operation unit 50 transmits information about the selected operation mode to the driving assistance device 60.

[0016] <Driving assistance devices> The driving assistance device 60 assists the driver in driving the vehicle 10. The driving assistance device 60 includes a processing circuit 61. An example of the processing circuit 61 is an electronic control device. In this case, the processing circuit 61 includes a CPU 62, a first memory 63, and a second memory 64. The first memory 63 stores a control program executed by the CPU 62 and various maps referenced by the CPU 62. The second memory 64 stores the results of calculations by the CPU 62. As will be described in more detail below, a portion of the storage area of ​​the first memory 63 functions as a "storage unit 101" that stores acceleration characteristics indicating the relationship between the accelerator opening degree AC, which is the amount of operation of the accelerator pedal 11 by the driver, and the acceleration DVS of the vehicle 10.

[0017] The CPU 62 executes the control program in the first memory 63, and the processing circuit 61 functions as various functional units for assisting the driver in operating the vehicle. 2 shows functional units that operate when the acceleration / deceleration operation mode is selected. The functional units include a storage unit 101, a request derivation unit 103, and a command processing unit 105.

[0018] <Storage section> The storage unit 101 stores an acceleration characteristic map MP1 as an acceleration characteristic that indicates the relationship between the accelerator opening AC and the acceleration DVS of the vehicle 10. When the vehicle 10 accelerates, the acceleration DVS takes a positive value. On the other hand, when the vehicle 10 decelerates, the acceleration DVS takes a negative value.

[0019] In the acceleration characteristics map MP1, the greater the accelerator opening AC, the greater the acceleration DVS. Specifically, an accelerator opening AC greater than 0 (zero) is set as the reference opening ACb. When the accelerator opening AC is the reference opening ACb, the acceleration DVS becomes 0 (zero). When the accelerator opening AC is less than the reference opening ACb, the acceleration DVS becomes a negative value. When the accelerator opening AC is greater than the reference opening ACb, the acceleration DVS becomes a positive value.

[0020] <Requirement derivation part> The requirement derivation unit 103 derives the acceleration DVS corresponding to the accelerator pedal position AC as the required acceleration DVSRq of the vehicle 10 based on the acceleration characteristics map MP1. The required acceleration DVSRq is a required value of the acceleration DVS for the vehicle 10. The requirement derivation unit 103 reads out the acceleration DVS corresponding to the accelerator pedal position AC from the acceleration characteristics map MP1. Then, the requirement derivation unit 103 sets the acceleration DVS read out from the acceleration characteristics map MP1 as the required acceleration DVSRq.

[0021] <Command Processing Unit> The command processing unit 105 derives at least one of a command driving force FdTr and a command braking force FbTr based on the required acceleration DVSRq. The command driving force FdTr is a command value for the driving force Fd. The command braking force FbTr is a command value for the braking force Fb.

[0022] Then, the command processing unit 105 transmits the derived command value to the drive device 20 and the braking device 30. Specifically, when the command processing unit 105 derives the command driving force FdTr, it transmits the command driving force FdTr to the drive control unit 22 of the drive device 20. When the command processing unit 105 derives the command braking force FbTr, it transmits the command braking force FbTr to the braking control unit 32 of the braking device 30.

[0023] When the drive control unit 22 receives the command drive force FdTr, it operates the power unit 21 so that the drive force Fd becomes the command drive force FdTr. When the brake control unit 32 receives the command braking force FbTr, it operates the brake actuator 31 so that the braking force Fb becomes the command braking force FbTr.

[0024] For example, the command processing unit 105 derives at least one of the command driving force FdTr and the command braking force FbTr based on a command value derivation map MP2. In the diagram showing the command value derivation map MP2 in FIG. 2, the longitudinal force Fx corresponding to the required acceleration DVSRq is indicated by a dashed line. The longitudinal force Fx is the value obtained by subtracting the braking force Fb from the driving force Fd. Therefore, when the driving force Fd is equal to the braking force Fb, the longitudinal force Fx becomes 0 (zero). When the driving force Fd is greater than the braking force Fb, the longitudinal force Fx becomes a positive value. When the driving force Fd is less than the braking force Fb, the longitudinal force Fx becomes a negative value. According to the command value derivation map MP2, the longitudinal force Fx becomes larger as the required acceleration DVSRq becomes larger.

[0025] A predetermined acceleration range RDVS is set in the command value derivation map MP2. The acceleration range RDVS is a range of acceleration DVS that includes 0 (zero). For example, the width of the acceleration range RDVS and the upper and lower limit values ​​of the acceleration range RDVS are preset ranges.

[0026] When the required acceleration DVSRq is smaller than the lower limit value of the acceleration range RDVS, the command processing unit 105 derives the absolute value of the longitudinal force Fx corresponding to the required acceleration DVSRq as the command braking force FbTr. In this case, the command processing unit 105 derives 0 (zero) as the command driving force FdTr. When the required acceleration DVSRq is greater than the upper limit value of the acceleration range RDVS, the command processing unit 105 derives the longitudinal force Fx corresponding to the required acceleration DVSRq as the command driving force FdTr. In this case, the command processing unit 105 derives 0 (zero) as the command braking force FbTr.

[0027] When the required acceleration DVSRq is included in the acceleration range RDVS, the command processing unit 105 derives the command driving force FdTr and the command braking force FbTr so as to satisfy the following conditions (A1) and (A2).

[0028] (A1) Both the command driving force FdTr and the command braking force FbTr are greater than 0 (zero). (A2) The difference between the command braking force FbTr and the command braking force FbTr is equal to the longitudinal force Fx according to the required acceleration DVSRq.

[0029] In detail, when the required acceleration DVSRq is included in the acceleration range RDVS and is greater than 0 (zero), the command processing unit 105 derives the command driving force FdTr and the command braking force FbTr so that the command driving force FdTr is greater than the command braking force FbTr. Furthermore, when the required acceleration DVSRq is included in the acceleration range RDVS and is less than 0 (zero), the command processing unit 105 derives the command driving force FdTr and the command braking force FbTr so that the command braking force FbTr is greater than the command driving force FdTr.

[0030] When the required acceleration DVSRq is within the acceleration range RDVS, the braking gradient, which is the amount of change in the command braking force FbTr relative to a change in the required acceleration DVSRq, is the same as the driving gradient, which is the amount of change in the command driving force FdTr relative to a change in the required acceleration DVSRq. In the example shown in Figure 2, when the required acceleration DVSRq is within the acceleration range RDVS, both the braking gradient and the driving gradient are constant regardless of the required acceleration DVSRq. However, the braking gradient and the driving gradient may change depending on the required acceleration DVSRq.

[0031] <Driving assistance processing> The driving assistance process, which is a series of processes executed by the processing circuit 61 when the acceleration / deceleration operation mode is selected, will be described with reference to Fig. 3. The processing circuit 61 repeatedly executes the driving assistance process at predetermined control intervals.

[0032] In step S11, the processing circuit 61 determines whether or not it has been determined that the acceleration / deceleration operation mode has been selected as the operation mode. If the acceleration / deceleration operation mode has not been selected (S11: NO), the processing circuit 61 temporarily terminates the driving assistance process. On the other hand, if the processing circuit 61 determines that the acceleration / deceleration operation mode has been selected (S11: YES), the processing circuit 61 proceeds to step S13.

[0033] In step S13, the processing circuit 61 acquires the accelerator opening AC as the operation amount of the operating member. In the following step S15, the processing circuit 61 functions as the demand derivation unit 103 to obtain the acceleration DVS corresponding to the accelerator opening AC based on the acceleration characteristics map MP1 stored in the first memory 63. Then, the processing circuit 61 derives the obtained acceleration DVS as the demand acceleration DVSRq.

[0034] In the next step S17, the processing circuit 61 functions as the command processing unit 105 to derive a command driving force FdTr and a command braking force FbTr according to the required acceleration DVSRq. At this time, the processing circuit 61 derives the command driving force FdTr and the command braking force FbTr based on the command value derivation map MP2. Then, in step S19, the processing circuit 61 functions as the command processing unit 105 to transmit the command driving force FdTr to the drive control unit 22 of the drive device 20. The processing circuit 61 transmits the command braking force FbTr to the braking control unit 32 of the braking device 30. Thereafter, the processing circuit 61 temporarily ends the driving assistance process.

[0035] <Actions and Effects of This Embodiment> The operation and effect of the vehicle 10 when traveling uphill on an off-road road will be described with reference to Figures 4 and 5. Here, the case where the acceleration / deceleration operation mode is selected will be described as an example, while the case where the normal operation mode is selected will be described as a first comparative example. In Figures 5A to 5C, the solid lines indicate the changes in vehicle speed VS, driving force Fd, and braking force Fb in the example. In Figures 5A to 5C, the two-dot chain lines indicate the changes in vehicle speed VS, driving force Fd, and braking force Fb in the first comparative example. Figure 5D shows the changes in accelerator opening AC in the example.

[0036] As shown in FIG. 5, in this embodiment, the accelerator pedal 11 is not operated before timing t11. That is, the accelerator opening AC is 0 (zero). Therefore, in this embodiment, the processing circuit 61 derives 0 (zero) as the command driving force FdTr and derives a value greater than 0 (zero) as the command braking force FbTr. The processing circuit 61 then transmits this command braking force FbTr to the braking control unit 32. Therefore, the brake actuator 31 is operated based on this command braking force FbTr. As a result, a braking force Fb is applied to the vehicle 10, and the vehicle 10 is maintained in a stopped state.

[0037] In the first comparative example, the driver operates the brake pedal 12 to apply a braking force Fb to the vehicle 10. This keeps the vehicle 10 stopped. At timing t11 while the vehicle 10 is stopped, the driver starts a vehicle operation to start the vehicle 10.

[0038] In the first comparative example, the driver releases the brake pedal 12 and then begins to operate the accelerator pedal 11. That is, the release of the brake pedal 12 begins at timing t11, and the driver then begins to operate the accelerator pedal 11 at timing t12. That is, as shown by the two-dot chain lines in FIGS. 5B and 5C, a time lag occurs between the time when the braking force Fb becomes 0 (zero) and the time when the driving force Fd begins to increase. During this time lag, no force is acting on the vehicle 10 to prevent the vehicle 10 from rolling downhill. Therefore, the vehicle 10 temporarily rolls backward, as shown in FIGS. 5A and 4. In this case, the driver operates the accelerator pedal 11 in a panic, which tends to increase the rate at which the accelerator opening AC increases. As a result, when the vehicle 10 starts to move forward, the acceleration DVS of the vehicle 10 tends to increase, as shown in FIG. 5A.

[0039] In contrast, in this embodiment, because the acceleration / deceleration operation mode is selected, the driver can adjust the braking force Fb and the driving force Fd by operating the accelerator pedal 11 without operating the brake pedal 12. That is, when operation of the accelerator pedal 11 begins at timing t11, the processing circuit 61 reduces the command braking force FbTr in accordance with an increase in the accelerator opening AC. The braking control unit 32 operates the brake actuator 31 based on this command braking force FbTr, so that the braking force Fb is reduced.

[0040] At time t12 while the braking force Fb is still being applied to the vehicle 10, the required acceleration DVSRq corresponding to the accelerator pedal position AC falls within the acceleration range RDVS. Therefore, the processing circuit 61 decreases the command braking force FbTr and increases the command driving force FdTr in response to an increase in the accelerator pedal position AC. The processing circuit 61 then transmits the command braking force FbTr to the braking control unit 32 and the command driving force FdTr to the driving control unit 22. Therefore, while the braking force Fb is being applied to the vehicle 10, the driving force Fd of the vehicle 10 begins to increase. On an uphill road, the driving force Fd acts on the vehicle 10 to prevent the vehicle 10 from rolling downhill. Therefore, even if the braking force Fb is reduced, the increased driving force Fd prevents the vehicle 10 from rolling downhill.

[0041] Then, at timing t13, when the longitudinal force Fx increases with an increase in the driving force Fd and a decrease in the braking force Fb, the vehicle 10 starts moving. In other words, the driving assistance device 60 can start the vehicle 10 after preventing the vehicle 10, which has stopped on an uphill off-road road, from sliding down the slope. Therefore, the driving assistance device 60 can improve the off-road running ability of the vehicle 10.

[0042] Note that even after the vehicle 10 starts moving, as long as the required acceleration DVSRq is within the acceleration range RDVS, the processing circuit 61 decreases the command braking force FbTr and increases the command driving force FdTr in response to an increase in the required acceleration DVSRq. In the example shown in FIG. 5, the required acceleration DVSRq is no longer within the acceleration range RDVS at time t14, so the processing circuit 61 derives 0 (zero) as the command braking force FbTr. As a result, the braking force Fb is not applied to the vehicle 10 while it is moving. Therefore, from time t14 onwards, the driver can drive the vehicle 10 without feeling any dragging sensation due to the braking force Fb.

[0043] With reference to Figures 6 and 7, the operation and effect of stopping a vehicle 10 traveling on an off-road downhill road will be described. Here, a case where the acceleration / deceleration operation mode is selected will be described as an example, while a case where the normal operation mode is selected will be described as a second comparative example. In Figures 7A to 7C, the solid lines indicate the changes in vehicle speed VS, driving force Fd, and braking force Fb in the example. In Figures 7A to 7C, the two-dot chain lines indicate the changes in vehicle speed VS, driving force Fd, and braking force Fb in the second comparative example. Figure 7D shows the changes in accelerator opening AC in the example.

[0044] As shown in Fig. 7, in the embodiment, before timing t21, the driver operates the accelerator pedal 11 and the vehicle 10 travels downhill. Therefore, in the embodiment, the processing circuit 61 derives 0 (zero) as the command braking force FbTr and also derives a value greater than 0 (zero) as the command driving force FdTr. The processing circuit 61 then transmits this command driving force FdTr to the drive control unit 22. Therefore, the power unit 21 is operated based on this command driving force FdTr, and the vehicle 10 travels.

[0045] In the example shown in FIG. 7, the driver starts a vehicle operation to stop the vehicle 10 at timing t21. In the second comparative example, the driver releases the accelerator pedal 11 and then begins to operate the brake pedal 12. That is, the release of the accelerator pedal 11 begins at timing t21, and the brake pedal 12 begins to be operated at a subsequent timing t24. That is, as shown by the two-dot chain lines in FIGS. 7B and 7C, a time lag occurs between the time when the driving force Fd becomes 0 (zero) and the time when the braking force Fb starts to increase. During this time lag, no force that slows the vehicle 10 is applied to the vehicle 10. Therefore, as shown in FIGS. 6A and 7, the vehicle 10 does not decelerate. In this case, the driver panics and operates the brake pedal 12. Then, when the braking force Fb becomes sufficiently large, the vehicle 10 stops on a downhill road. That is, in the second comparative example, the vehicle 10 may stop after the vehicle speed VS, which is the traveling speed of the vehicle 10, temporarily increases. Furthermore, a large time lag occurs between the time when the vehicle operation to stop the vehicle 10 is started and the time when the vehicle 10 actually stops.

[0046] In contrast, in this embodiment, because the acceleration / deceleration operation mode is selected, the driver can adjust the braking force Fb and the driving force Fd by operating the accelerator pedal 11 without operating the brake pedal 12. That is, when the accelerator opening AC is reduced by operating the accelerator pedal 11 from timing t21, the processing circuit 61 reduces the command driving force FdTr in accordance with the reduction in the accelerator opening AC. The drive control unit 22 operates the power unit 21 based on this command driving force FdTr, and the driving force Fd is reduced.

[0047] At time t22 while the driving force Fd is still being applied to the vehicle 10, the required acceleration DVSRq corresponding to the accelerator pedal position AC falls within the acceleration range RDVS. Therefore, the processing circuit 61 decreases the commanded driving force FdTr and increases the commanded braking force FbTr in response to a decrease in the accelerator pedal position AC. The processing circuit 61 then transmits this commanded braking force FbTr to the braking control unit 32 and also transmits this commanded driving force FdTr to the drive control unit 22. Then, while the driving force Fd is being applied to the vehicle 10, the braking force Fb of the vehicle 10 begins to increase.

[0048] After timing t22, the braking force Fb is increased in response to a decrease in the accelerator pedal position AC. Therefore, as shown in FIG. 7A, the increase in vehicle speed VS is suppressed compared to the second comparative example. Then, at timing t23, the required acceleration DVSRq reaches the lower limit of the acceleration range RDVS, and therefore, after timing t23, the processing circuit 61 derives 0 (zero) as the command driving force FdTr. Therefore, after timing t23, of the driving force Fd and the braking force Fb, only the braking force Fb is applied to the vehicle 10. If the braking force Fb continues to increase in response to a decrease in the accelerator pedal position AC, the vehicle 10 will stop at timing t25.

[0049] That is, the driving assistance device 60 can suppress a temporary increase in the vehicle speed VS when stopping the vehicle 10 on an off-road downhill road. Furthermore, the driving assistance device 60 can shorten the time lag between when the driver starts a vehicle operation to stop the vehicle 10 and when the vehicle 10 actually stops. Therefore, the driving assistance device 60 can improve the off-road running performance of the vehicle 10.

[0050] <Example of change> The above embodiment can be modified as follows: The above embodiment and the following modifications can be combined with each other within the scope of technical compatibility.

[0051] The acceleration characteristics map MP1 may be configured to change the relationship between the accelerator pedal position AC and the acceleration DVS as shown in Figure 8. For example, the processing circuit 61 may be configured to change the acceleration characteristics map MP1 from the relationship shown by the dashed line in Figure 8 to the relationship shown by the solid line in Figure 8 in accordance with the driver's preference. Also, for example, the processing circuit 61 may be configured to change the acceleration characteristics map MP1 depending on the weather, road surface conditions, etc. The road surface conditions here include the μ value of the road surface, the road surface roughness index, and the road surface gradient.

[0052] The acceleration range RDVS may be changed in the command value derivation map MP2. For example, the processing circuit 61 may be configured to change at least one of the width of the acceleration range RDVS, the upper limit of the acceleration range RDVS, and the lower limit of the acceleration range RDVS in response to the driver's request. Furthermore, for example, the processing circuit 61 may be configured to change at least one of the width of the acceleration range RDVS, the upper limit of the acceleration range RDVS, and the lower limit of the acceleration range RDVS in response to weather, road surface conditions, vehicle speed VS, etc. The road surface conditions referred to here include the μ value of the road surface, the road surface roughness index, and the road surface gradient.

[0053] The acceleration range RDVS may be a range of the acceleration DVS that does not include 0 (zero). The operating member may be a member other than the accelerator pedal 11. For example, the driving assistance device 60 may cause the brake pedal 12 to function as the operating member. The vehicle may also have an operating member dedicated to the acceleration / deceleration operation mode, separate from the accelerator pedal 11 and the brake pedal 12. An example of such an operating member is a lever. In this case, it is preferable that the operating member be displaceable in a first operating direction and a second operating direction that is the opposite direction to the first operating direction. For example, the first operating direction is the operating direction when accelerating the vehicle. The second operating direction is the operating direction when decelerating the vehicle.

[0054] An example of an acceleration characteristics map MP11 when such an operating member is used is shown by a solid line in Figure 9. When the operating member is displaced from the reference position in the first operating direction X1, the operating amount QS of the operating member becomes a positive value. When the operating member is displaced from the reference position in the second operating direction X2, the operating amount QS of the operating member becomes a negative value. When the operating member is located at the reference position, the operating amount QS is 0 (zero). In the acceleration characteristics map MP11, when the operating amount QS is a positive value, the acceleration DVS becomes a positive value. When the operating amount QS is a negative value, the acceleration DVS becomes a negative value.

[0055] Even when such an operating member is employed, the acceleration characteristics map MP11 may be changed from the characteristics shown by the solid line in FIG. 9 to the characteristics shown by the dashed line in FIG. The acceleration characteristic may be a relational expression that indicates the relationship between the amount of operation of the operating member and the acceleration, instead of a map such as that shown in FIG.

[0056] In the above embodiment, an electronic control unit that functions as the driving assistance device 60 is provided separately from the electronic control unit that functions as the drive control unit 22, but this is not limited to this. That is, the electronic control unit that functions as the drive control unit 22 may also function as the driving assistance device 60. In this case, various information and commands can be transmitted and received between the driving assistance device 60 and the drive control unit 22 without going through an in-vehicle network.

[0057] In the above embodiment, an electronic control unit that functions as the driving assistance device 60 is provided separately from the electronic control unit that functions as the braking control unit 32, but this is not limited to this. That is, the electronic control unit that functions as the braking control unit 32 may also function as the driving assistance device 60. In this case, various information and commands can be transmitted and received between the driving assistance device 60 and the braking control unit 32 without going through an in-vehicle network.

[0058] The CPU 62, the first memory 63, and the second memory 64 do not all need to be mounted on the same board. That is, the CPU 62, the first memory 63, and the second memory 64 may be mounted separately, such as the drive control unit 22 and the braking control unit 32.

[0059] The processing circuit 61 is not limited to a circuit having a CPU and ROM and executing software processing. In other words, the processing circuit 61 may have any one of the following configurations (a), (b), and (c):

[0060] (a) The processing circuit 61 includes one or more processors that execute various processes according to a computer program. The processor includes a CPU and memory such as RAM and ROM. The memory stores program code or instructions configured to cause the CPU to execute processes. Memory, i.e., computer-readable media, includes any available media that can be accessed by a general-purpose or special-purpose computer.

[0061] (b) The processing circuit 61 includes one or more dedicated hardware circuits that perform various processes. Examples of dedicated hardware circuits include application specific integrated circuits (ASICs) or FPGAs. ASIC is an abbreviation for "Application Specific Integrated Circuit." FPGA is an abbreviation for "Field Programmable Gate Array."

[0062] (c) The processing circuitry 61 includes one or more processors that execute some of the various processes in accordance with a computer program, and one or more dedicated hardware circuits that execute the remaining processes among the various processes.

[0063] <Other technical ideas> The technical ideas that can be understood from the above-described embodiment and modified examples will be described. [Supplementary Note 1] The command processing unit: When the required acceleration is greater than an upper limit of the acceleration range, a driving force corresponding to the required acceleration is derived as a command value of the driving force; When the required acceleration is smaller than the lower limit of the acceleration range, it is preferable to derive a braking force corresponding to the required acceleration as the braking force command value.

[0064] [Appendix 2] The command processing unit: When the required acceleration is greater than an upper limit of the acceleration range, deriving 0 (zero) as the braking force command value; When the required acceleration is smaller than the lower limit of the acceleration range, it is preferable to derive 0 (zero) as the command value of the driving force.

[0065] The expression "at least one" used herein means "one or more" of the desired options. As an example, the expression "at least one" used herein means "only one option" or "both of two options" if the number of options is two. As another example, the expression "at least one" used herein means "only one option" or "any combination of two or more options" if the number of options is three or more. [Explanation of symbols]

[0066] 10...Vehicle 11...Accelerator pedal (an example of an operating member) 12...Brake pedal (an example of an operating member) 20...Driver 30...braking device 60...Driving assistance device 61...Processing circuit 62...CPU 63...First memory 64...Second memory 101...Storage section 103...Requirement derivation part 105...Command processing unit

Claims

1. The present invention is applied to a vehicle including an operating member that is operated to adjust the acceleration of the vehicle, a drive device that adjusts the drive force of the vehicle, and a braking device that adjusts the braking force of the vehicle, a storage unit that stores an acceleration characteristic indicating a relationship between an operation amount of the operation member and an acceleration of the vehicle; a demand derivation unit that derives, based on the acceleration characteristics, an acceleration of the vehicle corresponding to the operation amount as a demand acceleration; a command processing unit that transmits a command value corresponding to the required acceleration to the drive device and the braking device, When the required acceleration is within a predetermined acceleration range, the command processing unit derives the command values ​​for the driving force and the braking force so that both the command value for the driving force and the command value for the braking force are greater than 0 (zero) and the difference between the command value for the driving force and the command value for the braking force is a value corresponding to the required acceleration. Driving assistance device.

2. the acceleration range is a range of acceleration of the vehicle that includes 0 (zero); The command processing unit When the required acceleration is within the acceleration range and is greater than 0 (zero), deriving the command value for the driving force and the command value for the braking force so that the command value for the driving force is greater than the command value for the braking force; When the required acceleration is within the acceleration range and is smaller than 0 (zero), the driving force command value and the braking force command value are derived so that the braking force command value is larger than the driving force command value. The driving assistance device according to claim 1 .

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