Driving assistance device and driving assistance method

Abstract

A driving assistance device (60) includes a memory (101) that stores an acceleration characteristic, a request derivation section (103) configured to derive, based on the acceleration characteristic, an acceleration of a vehicle (10) corresponding to an operation amount of an operation member as a request acceleration, and a command processing section (105) configured to send a command value based on the request acceleration to a driving device (20) and a braking device (30). The command processing section (105) is further configured to derive a driving force command value and a braking force command value so as to satisfy both of the driving force command value and the braking force command value being greater than zero and a difference between the driving force command value and the braking force command value being a value corresponding to the request acceleration, in a case where the request acceleration is included in a prescribed acceleration range.

Description

Technical Field

[0001] This disclosure relates to driving assistance devices and methods that assist drivers in driving vehicles. Background Technology

[0002] Patent document 1 discloses an example of a traction control device that adjusts the braking force of the wheels when a vehicle is traveling on off-road conditions.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2004-90886

[0004] As a driving technique to improve vehicle performance in off-road conditions, simultaneous operation of both the accelerator and brake pedals is known. Specifically, simultaneous operation involves using the right foot to operate the accelerator pedal and the left foot to operate the brake pedal simultaneously. By performing this simultaneous operation, the driver can adjust the vehicle's driving and braking forces at the same time. However, while highly skilled drivers can perform this simultaneous operation when driving off-road, it is difficult for drivers other than those with advanced driving skills. Summary of the Invention

[0005] According to one aspect of this disclosure, a driving assistance device for a vehicle is provided. The vehicle includes: an operating component operated to adjust the vehicle's acceleration; a drive unit configured to adjust the vehicle's driving force; and a braking device configured to adjust the vehicle's braking force. The driving assistance device includes: a memory storing acceleration characteristics representing the relationship between the operating amount of the operating component and the vehicle's acceleration; a request derivation unit configured to derive a requested acceleration from the vehicle's acceleration corresponding to the operating amount based on the acceleration characteristics; and an instruction processing unit configured to send an instruction value corresponding to the requested acceleration to the drive unit and the braking device. The instruction processing unit is further configured to derive instruction values ​​for the driving force and the braking force when the requested acceleration is within a predetermined acceleration range, such that both the instruction values ​​for the driving force and the braking force are greater than 0 (zero), and the difference between the instruction values ​​for the driving force and the braking force is a value corresponding to the requested acceleration.

[0006] According to another aspect of this disclosure, a driving assistance method for a vehicle is provided. The vehicle includes: an operating component operated to adjust the vehicle's acceleration; a drive unit configured to adjust the vehicle's driving force; and a braking device configured to adjust the vehicle's braking force. The driving assistance method includes: deriving a required acceleration from the vehicle's acceleration corresponding to the operating component's operation amount as a desired acceleration based on acceleration characteristics representing the relationship between the operating component's operation amount and the vehicle's acceleration; deriving a command value corresponding to the required acceleration; and sending the command value corresponding to the required acceleration to the drive unit and the braking device. Deriving the command value corresponding to the required acceleration includes: if the required acceleration is within a predetermined acceleration range, deriving a command value for the driving force and a command value for the braking force, such 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. Attached Figure Description

[0007] Figure 1 This is a configuration diagram showing a schematic structure of a vehicle equipped with a driving assistance device according to an embodiment.

[0008] Figure 2 It is shown Figure 1 A block diagram illustrating the functional structure of a driver assistance system.

[0009] Figure 3 It is shown Figure 1 The flowchart shows a series of processes performed by the processing circuitry of the driver assistance device.

[0010] Figure 4 It shows how to stop on an uphill road. Figure 1 A diagram illustrating the starting state of a vehicle.

[0011] Figure 5 It is to stop on an uphill road. Figure 1 The timing diagram of the vehicle starting.

[0012] Figure 6 It shows that Figure 1 A diagram illustrating a vehicle stopped on a downhill slope.

[0013] Figure 7 Is to make Figure 1 The timing diagram of the vehicles stopping on the downhill road.

[0014] Figure 8 It is shown Figure 2 The diagram shows a modified example of the acceleration characteristic mapping.

[0015] Figure 9This is a diagram illustrating an example of an acceleration characteristic mapping in another variation of a vehicle equipped with an operating component dedicated to acceleration and deceleration operation modes. Detailed Implementation

[0016] The following is in accordance with Figures 1 to 7 One embodiment of the driving assistance device and driving assistance method will be described.

[0017] <General Components of a Vehicle>

[0018] Figure 1 A schematic diagram of a vehicle 10 equipped with a driver assistance device 60 is shown. The vehicle 10 includes an accelerator pedal 11, a brake pedal 12, a drive unit 20, a braking unit 30, various sensors, and a switching operation unit 50.

[0019] The drive unit 20 adjusts the driving force Fd of the vehicle 10. The drive unit 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 driving force Fd of the vehicle 10 by actuating the power unit 21. Furthermore, the drive control unit 22 is configured to transmit and receive various information and commands with the driver assistance device 60 via an in-vehicle network.

[0020] The braking system 30 adjusts the braking force Fb of the vehicle 10. The braking system 30 includes a brake actuator 31 and a brake control unit 32 that controls the brake actuator 31. One example of the brake control unit 32 is an electronic control device. The brake control unit 32 controls the braking force Fb of the vehicle 10 by actuating the brake actuator 31. Furthermore, the brake control unit 32 is configured to transmit and receive various information and commands with the driver assistance device 60 via an in-vehicle network.

[0021] <Sensor>

[0022] Multiple sensors output detection signals corresponding to the detection results to the driver assistance device 60. The vehicle 10 is equipped with sensors, including operation-related sensors that detect information related to the driver's operation, and state quantity detection sensors that detect state quantities of the vehicle 10.

[0023] The operation-related sensors include a throttle sensor 41 and a brake sensor 42. The throttle sensor 41 detects the amount of operation by the driver on the accelerator pedal 11. The brake sensor 42 detects the amount of operation by the driver on the brake pedal 12. The brake sensor may also be a sensor that detects the force applied to the brake pedal 12 by the driver or a related value thereof. Hereinafter, the operation amount based on the detection signal from the throttle sensor 41 will be referred to as "throttle opening AC". The operation amount based on the detection signal from the brake sensor 42 will be referred to as "brake operation amount BP".

[0024] The state quantity detection sensors include a front and rear acceleration sensor 44, a lateral acceleration sensor 45, and a wheel speed sensor 46. The front and rear acceleration sensor 44 detects the front-to-rear acceleration of the vehicle 10. The lateral acceleration sensor 45 detects the lateral acceleration of the vehicle 10. The 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 from the front and rear acceleration sensor 44 will be referred to as "front and rear acceleration Gx". The acceleration based on the detection signal from the lateral acceleration sensor 45 will be referred to as "lateral acceleration Gy". The rotational speed based on the detection signal from the wheel speed sensor 46 will be referred to as "wheel speed VW".

[0025] <Switching Operation Section>

[0026] The switching operation unit 50 is an operation unit for switching the operating mode of the vehicle 10. The vehicle 10 is prepared with operating modes including a normal operating mode and an acceleration / deceleration operating mode. When the normal operating mode is selected, the driving force Fd of the vehicle 10 is adjusted by operating the accelerator pedal 11, and the braking force Fb of the vehicle 10 is adjusted by operating the brake pedal 12. When the acceleration / deceleration operating 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. That is, when the acceleration / deceleration operating mode is selected, the accelerator pedal 11 functions as an "operating component" operated to adjust the acceleration of the vehicle 10.

[0027] By operating the switching control unit 50, occupants of the vehicle 10, such as the driver, can select either a normal operating mode or an acceleration / deceleration operating mode. The switching control unit 50 then sends information related to the selected operating mode to the driver assistance device 60.

[0028] <Driver Assistance Devices>

[0029] A driving assistance device 60 assists the driver in driving the vehicle 10. The driving assistance device 60 includes a processing circuit 61. One example of the processing circuit 61 is an electronic control device. In this case, the processing circuit 61 has a CPU 62, a first memory 63, and a second memory 64. The first memory 63 stores the control program executed by the CPU 62 and various mapping diagrams referenced by the CPU 62. The second memory 64 stores the calculation results of the CPU 62. As detailed later, a portion of the storage area of ​​the first memory 63 functions as a "memory" that stores acceleration characteristics representing the relationship between the throttle opening AC (the amount of the driver's operation on the accelerator pedal 11) and the acceleration DVS (Device Variable Speed) of the vehicle 10.

[0030] The CPU 62 executes the control program of the first memory 63, and the processing circuit 61 performs various functions to assist the driver in operating the vehicle.

[0031] Figure 2 The functional units that operate when the acceleration / deceleration operation mode is selected are shown. In addition to the storage unit 101, which serves as memory, the multiple functional units include a request output unit 103 and an instruction processing unit 105.

[0032] Storage Department

[0033] Storage unit 101 stores acceleration characteristic mapping map MP1, which represents the relationship between throttle opening AC and vehicle 10 acceleration DVS. When vehicle 10 accelerates, acceleration DVS is positive. On the other hand, when vehicle 10 decelerates, acceleration DVS is negative.

[0034] In the acceleration characteristic mapping diagram MP1, the larger the throttle opening AC, the larger the acceleration DVS. Specifically, the reference opening ACb is set to a throttle opening AC greater than 0 (zero). When the throttle opening AC is the reference opening ACb, the acceleration DVS is 0 (zero). When the throttle opening AC is less than the reference opening ACb, the acceleration DVS is negative. When the throttle opening AC is greater than the reference opening ACb, the acceleration DVS is positive.

[0035] <Requirements for Export Department>

[0036] The request export unit 103, based on the acceleration characteristic map MP1, exports the acceleration DVS corresponding to the throttle opening AC as the required acceleration DVSRq for the vehicle 10. The required acceleration DVSRq is the required value of the acceleration DVS for the vehicle 10. The request export unit 103 reads the acceleration DVS corresponding to the throttle opening AC from the acceleration characteristic map MP1. Then, the request export unit 103 sets the acceleration DVS read from the acceleration characteristic map MP1 as the required acceleration DVSRq.

[0037] <Instruction Processing Department>

[0038] The instruction processing unit 105 derives at least one of the instruction driving force FdTr and the instruction braking force FbTr based on the required acceleration DVSRq. The instruction driving force FdTr is the instruction value of the driving force Fd. The instruction braking force FbTr is the instruction value of the braking force Fb.

[0039] Then, the command processing unit 105 sends the derived command value to the drive unit 20 and the braking unit 30. Specifically, when the command driving force FdTr is derived, the command processing unit 105 sends the command driving force FdTr to the drive control unit 22 of the drive unit 20. When the command braking force FbTr is derived, the command processing unit 105 sends the command braking force FbTr to the braking control unit 32 of the braking unit 30.

[0040] When the drive control unit 22 receives the commanded drive force FdTr, it activates the power unit 21 to make the drive force Fd become the commanded drive force FdTr. When the brake control unit 32 receives the commanded braking force FbTr, it activates the brake actuator 31 to make the braking force Fb become the commanded braking force FbTr.

[0041] For example, the instruction processing unit 105 derives a mapping map MP2 based on the instruction value, and derives at least one of the instruction driving force FdTr and the instruction braking force FbTr.

[0042] exist Figure 2 In the instruction value derived mapping MP2, the forward and backward force Fx corresponding to the required acceleration DVSRq is represented by a dashed line. The forward and backward force Fx is the value obtained by subtracting the braking force Fb from the driving force Fd. Therefore, when the driving force Fd equals the braking force Fb, the forward and backward force Fx is 0 (zero). When the driving force Fd is greater than the braking force Fb, the forward and backward force Fx is positive. When the driving force Fd is less than the braking force Fb, the forward and backward force Fx is negative. According to the instruction value derived mapping MP2, the larger the required acceleration DVSRq, the larger the forward and backward force Fx.

[0043] In the instruction value export mapping MP2, a specified acceleration range RDVS is set. The acceleration range RDVS is the range of acceleration DVS including 0 (zero). For example, the width, upper limit and lower limit of the acceleration range RDVS are preset ranges.

[0044] When the required acceleration DVSRq is less than the lower limit of the acceleration range RDVS, the command processing unit 105 derives the absolute value of the forward and backward 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 of the acceleration range RDVS, the command processing unit 105 derives the forward and backward 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.

[0045] When the required acceleration DVSRq is included in the acceleration range RDVS, the instruction processing unit 105 derives the instruction driving force FdTr and the instruction braking force FbTr to satisfy the following conditions (A1) and (A2).

[0046] (A1) Both the command driving force FdTr and the command braking force FbTr are greater than 0 (zero).

[0047] (A2) The difference between the commanded braking force FbTr and the commanded braking force FbTr is equal to the front and rear forces Fx corresponding to the required acceleration DVSRq.

[0048] Specifically, when the required acceleration DVSRq is included within the acceleration range RDVS and the required acceleration DVSRq is greater than 0 (zero), the instruction processing unit 105 derives the instruction driving force FdTr and the instruction braking force FbTr, such that the instruction driving force FdTr is greater than the instruction braking force FbTr. Furthermore, when the required acceleration DVSRq is included within the acceleration range RDVS and the required acceleration DVSRq is less than 0 (zero), the instruction processing unit 105 derives the instruction driving force FdTr and the instruction braking force FbTr, such that the instruction braking force FbTr is greater than the instruction driving force FdTr.

[0049] Furthermore, when the required acceleration DVSRq is included within the acceleration range RDVS, the change in the commanded braking force FbTr relative to the change in the required acceleration DVSRq, i.e., the braking slope, is the same as the change in the commanded driving force FdTr relative to the change in the required acceleration DVSRq, i.e., the driving slope. Figure 2 In the example shown, when the required acceleration DVSRq is included within the acceleration range RDVS, the braking slope and driving slope are constant regardless of the required acceleration DVSRq. However, the braking slope and driving slope can also be changed according to the required acceleration DVSRq.

[0050] <Driver Assistance Processing>

[0051] Reference Figure 3 The following describes a series of processes performed by the processing circuit 61 when the acceleration / deceleration operation mode is selected, namely, driving assistance processes. The processing circuit 61 repeatedly performs driving assistance processes at a predetermined control cycle.

[0052] In step S11, the processing circuit 61 determines whether the acceleration / deceleration operation mode has been selected as the operating mode. If the acceleration / deceleration operation mode is not selected (S11: No), the processing circuit 61 temporarily terminates the driver assistance processing. On the other hand, if the acceleration / deceleration operation mode is selected (S11: Yes), the processing circuit 61 transfers the processing to step S13.

[0053] In step S13, the processing circuit 61 acquires the throttle opening AC as the operating quantity of the operating component.

[0054] In the next step S15, the processing circuit 61 functions as a demand derivation unit 103 to obtain the acceleration DVS corresponding to the throttle opening AC based on the acceleration characteristic mapping MP1 stored in the first memory 63. Then, the processing circuit 61 derives the obtained acceleration DVS as the demand acceleration DVSRq.

[0055] In the next step S17, the processing circuit 61, functioning as the command processing unit 105, derives the command driving force FdTr and command braking force FbTr corresponding to the required acceleration DVSRq. At this time, the processing circuit 61 derives the mapping map MP2 based on the command value, and derives the command driving force FdTr and command braking force FbTr. Then, in step S19, the processing circuit 61, functioning as the command processing unit 105, sends the command driving force FdTr to the drive control unit 22 of the drive device 20. The processing circuit 61 sends the command braking force FbTr to the brake control unit 32 of the braking device 30. Afterwards, the processing circuit 61 temporarily terminates the driver assistance processing.

[0056] <Function and Effects of This Implementation Method>

[0057] Reference Figure 4 and Figure 5 The function and effect of vehicle 10 when driving uphill on off-road terrain are explained. Here, the case where the acceleration / deceleration operation mode is selected is an example, and the case where the normal operation mode is selected is a first comparative example. Figure 5 In (A) to (C), the shift of vehicle speed VS, driving force Fd, and braking force Fb in the embodiments is represented by solid lines. On the other hand, in Figure 5 In (A) to (C), the movement of the vehicle speed VS, driving force Fd, and braking force Fb in the first comparative example is represented by a double-dotted line. Figure 5 (D) shows the shift of throttle opening AC in the embodiment.

[0058] like Figure 5 As shown, in this embodiment, the accelerator pedal 11 is not operated before time 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. Then, the processing circuit 61 sends this command braking force FbTr to the brake control unit 32. Therefore, based on this command braking force FbTr, the brake actuator 31 actuates. As a result, since the braking force Fb is applied to the vehicle 10, the vehicle 10 remains stationary.

[0059] In the first comparative example, the driver operates the brake pedal 12, thereby applying braking force Fb to the vehicle 10. As a result, the vehicle 10 remains stationary.

[0060] At time t11 during the period when vehicle 10 is stationary, the driver begins the vehicle operation to start vehicle 10.

[0061] In the first comparative example, after releasing the brake pedal 12, the driver begins to operate the accelerator pedal 11. That is, the release of the brake pedal 12 begins at time t11, and the operation of the accelerator pedal 11 begins at a subsequent time t12. In other words, as... Figure 5 As shown by the double-dotted lines in (B) and (C), there is a time lag between the period when the braking force Fb becomes 0 (zero) and the period when the driving force Fd begins to increase. During this time lag, the force that inhibits the downward sliding of vehicle 10 does not act on vehicle 10. Therefore, as... Figure 5 (A) and Figure 4 As shown, vehicle 10 will temporarily reverse. In this situation, due to the driver's hasty operation of the accelerator pedal 11, the rate of increase in the accelerator opening AC is likely to be greater. As a result, when vehicle 10 begins to move forward, as... Figure 5 As shown in (A), the acceleration DVS of vehicle 10 tends to increase.

[0062] In contrast, in this embodiment, since the acceleration / deceleration operation mode is selected, the driver can adjust the braking force Fb and driving force Fd by operating the accelerator pedal 11 without operating the brake pedal 12. That is, when the accelerator pedal 11 is operated from time t11, the processing circuit 61 reduces the commanded braking force FbTr according to the increase in throttle opening AC. Since the brake control unit 32 actuates the brake actuator 31 based on this commanded braking force FbTr, the braking force Fb is reduced.

[0063] At time t12, while the braking force Fb is still applied to the vehicle 10, the required acceleration DVSRq corresponding to the throttle opening AC becomes included in the acceleration range RDVS. Therefore, the processing circuit 61 reduces the commanded braking force FbTr and increases the commanded driving force FdTr according to the increase in the throttle opening AC. Then, the processing circuit 61 sends such commanded braking force FbTr to the brake control unit 32 and such commanded driving force FdTr to the drive control unit 22. Therefore, while the braking force Fb is 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 as a force to prevent the vehicle 10 from sliding downhill. Therefore, even if the braking force Fb is reduced, the vehicle 10 can be prevented from sliding downhill by increasing the driving force Fd.

[0064] Therefore, at time t13, as the driving force Fd increases and the braking force Fb decreases, the front-rear force Fx increases, and the vehicle 10 starts moving. In other words, the driving assistance device 60 can enable the vehicle 10 to start moving while preventing it from sliding downhill from a stop on an uphill slope in off-road conditions. Therefore, the driving assistance device 60 can improve the driving performance of the vehicle 10 in off-road conditions.

[0065] Furthermore, even after vehicle 10 has started moving, during the period when the required acceleration DVSRq is contained within the acceleration range RDVS, the processing circuit 61 reduces the commanded braking force FbTr and increases the commanded driving force FdTr according to the increase in the required acceleration DVSRq. Figure 5 In the example shown, at time t14, the required acceleration DVSRq is no longer included in the acceleration range RDVS, so the processing circuit 61 derives 0 (zero) as the commanded braking force FbTr. Therefore, the braking force Fb is no longer applied to the moving vehicle 10. Thus, after time t14, the driver is able to keep the vehicle 10 moving without feeling any drag caused by the braking force Fb.

[0066] Reference Figure 6 and Figure 7 The function and effect of stopping a vehicle 10 traveling downhill on an off-road terrain will be explained. Here, the case where the acceleration / deceleration operation mode is selected is an example, and the case where the normal operation mode is selected is a second comparative example. Figure 7 In (A) to (C), the shift of vehicle speed VS, driving force Fd, and braking force Fb in the embodiments is represented by solid lines. On the other hand, in Figure 7 In (A) to (C), the movement of the vehicle speed VS, driving force Fd, and braking force Fb in the second comparative example is represented by a double-dotted line. Figure 7 (D) shows the shift of throttle opening AC in the embodiment.

[0067] like Figure 7 As shown, in this embodiment, before time t21, vehicle 10 is traveling downhill by the driver's operation of the accelerator pedal 11. Therefore, in this embodiment, processing circuit 61 derives 0 (zero) as the command braking force FbTr, and derives a value greater than 0 (zero) as the command driving force FdTr. Then, processing circuit 61 sends this command driving force FdTr to drive control unit 22. Therefore, based on this command driving force FdTr, power unit 21 operates, and vehicle 10 is moving.

[0068] exist Figure 7 In the example shown, at time t21, the driver begins the vehicle operation to stop vehicle 10.

[0069] In the second comparative example, after releasing the accelerator pedal 11, the driver begins to operate the brake pedal 12. That is, the accelerator pedal 11 is released at time t21, and the brake pedal 12 is operated at a subsequent time t24. In other words, as... Figure 7 As shown by the double-dotted lines in (B) and (C), there is a time lag between the period when the driving force Fd becomes 0 (zero) and the period when the braking force Fb begins to increase. During this time lag, the force that decelerates vehicle 10 does not act on vehicle 10. Therefore, as... Figure 7 (A) and Figure 6 As shown, vehicle 10 does not decelerate. In this situation, the driver frantically operates the brake pedal 12. Then, when the braking force Fb is large enough, vehicle 10 stops on the downhill road. That is, in the second comparative example, there is a situation where the vehicle 10 stops only after its travel speed, i.e., its vehicle speed VS, temporarily increases. Furthermore, a significant time lag occurs between the time when the vehicle operation to stop vehicle 10 begins and the time when vehicle 10 actually stops.

[0070] In contrast, in this embodiment, since 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 throttle opening AC is reduced by operating the accelerator pedal 11 from time t21, the processing circuit 61 reduces the commanded driving force FdTr according to the reduction in the throttle opening AC. Since the drive control unit 22 operates the power unit 21 based on this commanded driving force FdTr, the driving force Fd is reduced.

[0071] Thus, at time t22 when the driving force Fd is still applied to the vehicle 10, the required acceleration DVSRq corresponding to the throttle opening AC becomes included in the acceleration range RDVS. Therefore, the processing circuit 61 reduces the commanded driving force FdTr and increases the commanded braking force FbTr according to the decrease in throttle opening AC. Then, the processing circuit 61 sends such commanded braking force FbTr to the brake control unit 32 and such commanded driving force FdTr to the drive control unit 22. Thus, while the driving force Fd is applied to the vehicle 10, the braking force Fb of the vehicle 10 begins to increase.

[0072] After time t22, as the throttle opening AC decreases, the braking force Fb increases. Therefore, as... Figure 7As shown in (A), the increase in vehicle speed VS is suppressed compared to the second comparative example. Then, at time t23, since the acceleration DVSRq is required to reach the lower limit of the acceleration range RDVS, after time t23, the processing circuit 61 outputs 0 (zero) as the command driving force FdTr. Therefore, after time t23, only the driving force Fd and the braking force Fb are applied to the vehicle 10. Subsequently, if the braking force Fb is further increased according to the decrease in throttle opening AC, the vehicle 10 stops at time t25.

[0073] In other words, when the driver assistance device 60 stops the vehicle 10 on a downhill slope in off-road conditions, it can prevent the vehicle speed VS from temporarily increasing. Furthermore, the driver assistance device 60 can reduce the time lag between the driver initiating vehicle control to stop the vehicle 10 and the actual time the vehicle 10 comes to a stop. Therefore, the driver assistance device 60 can improve the driving performance of the vehicle 10 in off-road conditions.

[0074] <Example of Change>

[0075] The above-described embodiments can be implemented with modifications as follows. The above-described embodiments and the following modifications can be combined and implemented with each other within the scope of technical inconsistency.

[0076] • The acceleration characteristic mapping map MP1 can also be configured to be as follows: Figure 8 The diagram illustrates the relationship between throttle opening AC and acceleration DVS. For example, the processing circuit 61 can also be configured to adjust the acceleration characteristic map MP1 according to the driver's preference, for example... Figure 8 The relationship shown by the dashed line has changed to Figure 8 The relationship is shown by the solid line. Furthermore, for example, the processing circuit 61 can also be configured to change the speed characteristic mapping map MP1 according to variations in weather or road conditions. Road conditions here include the road surface μ value, the road condition index, and the road gradient.

[0077] • In the instruction value export mapping MP2, the acceleration range RDVS can also be changed. For example, the processing circuit 61 can also be configured to change at least one of the width of the speed range RDVS, the upper limit value of the acceleration range RDVS, and the lower limit value of the acceleration range RDVS according to the driver's request. Furthermore, for example, the processing circuit 61 can also change at least one of the width of the speed range RDVS, the upper limit value of the acceleration range RDVS, and the lower limit value of the acceleration range RDVS according to weather, road conditions, and vehicle speed VS. Road conditions mentioned here include the road surface μ value, the road surface severity index, and the road surface gradient.

[0078] • The acceleration range RDVS can also be the range of acceleration DVS that does not include 0 (zero).

[0079] The operating component can also be a component other than the accelerator pedal 11. For example, the driver assistance device 60 can also function as the brake pedal 12 as an operating component. The vehicle can also have a dedicated operating component for acceleration / deceleration operation modes, separate from the accelerator pedal 11 or the brake pedal 12. An example of such an operating component is a joystick. In this case, the operating component is preferably displaceable in a first operating direction and a second operating direction that is opposite to the first operating direction. For example, the first operating direction is the operating direction for accelerating the vehicle. The second operating direction is the operating direction for decelerating the vehicle.

[0080] With such an operating component, an example of the acceleration characteristic mapping MP11... Figure 9 As shown by the solid line. When the operating component moves from the reference position to the first operating direction X1, the operating amount QS of the operating component is positive. When the operating component moves from the reference position to the second operating direction X2, the operating amount QS of the operating component is negative. When the operating component is at the reference position, the operating amount QS is 0 (zero). In the acceleration characteristic mapping diagram MP11, when the operating amount QS is positive, the acceleration DVS is positive. When the operating amount QS is negative, the acceleration DVS is negative.

[0081] Furthermore, even when using this type of operating component, it can be configured to transfer the acceleration characteristic map MP11 from... Figure 9 The characteristic shown by the solid line has changed to Figure 9 The characteristics are shown by the dashed line.

[0082] • Acceleration characteristics can also be expressed as a formula relating the input quantity of the operating component to the acceleration, rather than... Figure 2 A mapping diagram as shown.

[0083] In the above embodiment, an electronic control device that functions as a driving assistance device 60 is provided separately from the electronic control device that functions as the drive control unit 22, but this is not a limitation. That is, the electronic control device that functions as the drive control unit 22 can also function as the driving assistance device 60. In this case, various information and commands can be sent and received between the driving assistance device 60 and the drive control unit 22 without going through the in-vehicle network.

[0084] In the above embodiment, an electronic control device that functions as a driver assistance device 60 is provided separately from the electronic control device that functions as the brake control unit 32, but this is not a limitation. That is, the electronic control device that functions as the brake control unit 32 can also function as the driver assistance device 60. In this case, the driver assistance device 60 and the brake control unit 32 can send and receive various information and commands without going through the in-vehicle network.

[0085] The CPU 62, the first memory 63, and the second memory 64 do not necessarily have to be mounted on the same substrate. That is, the CPU 62, the first memory 63, and the second memory 64 can also be mounted separately, just like the drive control unit 22 and the brake control unit 32.

[0086] • The processing circuit 61 is not limited to a configuration that includes a CPU and ROM and performs software processing. That is, the processing circuit 61 can be any of the following configurations (a), (b) and (c).

[0087] (a) The processing circuit 61 includes one or more processors that perform various processes according to a computer program. The processors include a CPU and memories such as RAM and ROM. The memories store program code or instructions configured to cause the CPU to perform processes. Memory, i.e., computer-readable media, includes any available media accessible to a general-purpose or special-purpose computer.

[0088] (b) The processing circuit 61 includes one or more dedicated hardware circuits that perform various processes. Examples of dedicated hardware circuits include, for example, application-specific integrated circuits (ASICs) or FPGAs. Furthermore, ASIC is an abbreviation for "Application Specific Integrated Circuit," and FPGA is an abbreviation for "Field Programmable Gate Array."

[0089] (c) The processing circuit 61 includes one or more processors that perform a portion of various processes according to a computer program, and one or more dedicated hardware circuits that perform the remaining processes in the various processes.

[0090] Furthermore, the expression "at least one" as used in this specification refers to "one or more" of the desired options. As an example, the expression "at least one" as used in this specification when there are two options means "only one option" or "both of the two options". As another example, the expression "at least one" as used in this specification when there are three or more options means "only one option" or "a combination of any two or more options".

Claims

1. A driving assistance device applied to a vehicle, the vehicle comprising: an operating component operated for adjusting the acceleration of the vehicle; a drive unit configured to adjust the driving force of the vehicle; and a braking device configured to adjust the braking force of the vehicle, the driving assistance device comprising: The memory stores acceleration characteristics that represent the relationship between the operation amount of the aforementioned operating component and the acceleration of the aforementioned vehicle. The requirement derivation unit is configured to derive the required acceleration from the vehicle's acceleration corresponding to the aforementioned operational amount, based on the aforementioned acceleration characteristics; and The command processing unit is configured to send command values ​​corresponding to the required acceleration to the drive device and the braking device. The command processing unit is further configured to, when the required acceleration is included within a specified acceleration range, derive the command value of the driving force and the command value of the braking force, such that the command value of the driving force and the command value of the braking force are both greater than 0 (zero), and the difference between the command value of the driving force and the command value of the braking force is a value corresponding to the required acceleration.

2. The driving assistance device according to claim 1, wherein, The above acceleration range includes the acceleration of the aforementioned vehicle at 0 (zero). The aforementioned instruction processing unit is further configured as follows: If the required acceleration is within the required acceleration range and the required acceleration is greater than 0 (zero), the command values ​​for the driving force and the braking force are derived such that the command value for the driving force is greater than the command value for the braking force. When the required acceleration is included within the required acceleration range and the required acceleration is less than 0 (zero), the command value of the driving force and the command value of the braking force are derived such that the command value of the braking force is greater than the command value of the driving force.

3. The driving assistance device according to claim 1 or 2, wherein, The aforementioned instruction processing unit is further configured as follows: If the required acceleration is greater than the upper limit of the required acceleration range, the driving force corresponding to the required acceleration will be derived as the command value of the driving force. If the required acceleration is less than the lower limit of the required acceleration range, the braking force corresponding to the required acceleration is derived as the command value of the braking force.

4. The driving assistance device according to claim 1 or 2, wherein, The aforementioned instruction processing unit is further configured as follows: Given that the required acceleration is greater than the upper limit of the acceleration range, 0 (zero) is derived as the command value for the braking force. If the acceleration is required to be less than the lower limit of the acceleration range, 0 (zero) is derived as the command value of the driving force.

5. A driving assistance method applied to a vehicle, the vehicle comprising: an operating component operated to adjust the acceleration of the vehicle; a drive unit configured to adjust the driving force of the vehicle; and a braking device configured to adjust the braking force of the vehicle, the driving assistance method comprising: Based on the acceleration characteristics that represent the relationship between the operation amount of the above-mentioned operating component and the acceleration of the above-mentioned vehicle, the acceleration of the above-mentioned vehicle corresponding to the operation amount is derived as the required acceleration. Export the command value corresponding to the acceleration required above; as well as The command value corresponding to the above-mentioned required acceleration is sent to the above-mentioned drive device and the above-mentioned braking device. The process of deriving the command value corresponding to the above-mentioned required acceleration includes: when the above-mentioned required acceleration is included within a specified acceleration range, deriving the command value of the above-mentioned driving force and the command value of the above-mentioned braking force, such that the command value of the above-mentioned driving force and the command value of the above-mentioned braking force are both greater than 0 (zero), and the difference between the command value of the above-mentioned driving force and the command value of the above-mentioned braking force is a value corresponding to the above-mentioned required acceleration.

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