Vehicle control devices and vehicle control methods

Abstract

This invention provides a vehicle control device and a vehicle control method. The driving control device includes a correction unit that performs a first correction process on a desired value when the vehicle is traveling uphill, and a second correction process on the desired value when the vehicle is traveling downhill. The first correction process corrects the desired value to increase the driving speed compared to a situation where the first correction process is not performed. The second correction process corrects the desired value to decrease the driving speed compared to a situation where the second correction process is not performed. During the execution of the first correction process, if a driver assistance device requests emergency braking of the vehicle, the correction unit reduces the correction amount of the desired value in the first correction process compared to a situation where emergency braking is not requested.

Description

Technical Field

[0001] This disclosure relates to a control device for vehicles and a control method for vehicles. Background Technology

[0002] Japanese Patent Application Publication No. 2019-98972 discloses a vehicle equipped with a drive unit that outputs driving force, a braking unit that outputs braking force, and an automatic driving control unit that implements automatic driving control. The automatic driving control unit calculates a feedback correction amount based on the deviation between the vehicle's target acceleration and its actual acceleration, and a feedforward correction amount based on factors such as road surface gradient. Furthermore, the automatic driving control unit controls the drive unit and the braking unit based on the feedback correction amount and the feedforward correction amount. Therefore, even if the gradient of the road surface on which the vehicle travels changes, the automatic driving control unit can ensure that the vehicle's actual acceleration follows the target acceleration.

[0003] When automatically adjusting the vehicle's speed as in autonomous driving control as described above, there may be situations where braking is required to avoid collisions with obstacles. In such cases, it is preferable to bring the vehicle to a stop earlier. Summary of the Invention

[0004] This disclosure provides a vehicle control device that automatically adjusts the vehicle's speed based on a request value input from a driving assistance device. The vehicle control device includes a correction unit that performs a first correction process on the request value when the vehicle is traveling uphill, and a second correction process on the request value when the vehicle is traveling downhill. The first correction process corrects the request value to an increase in speed compared to a situation where no first correction process is performed. The second correction process corrects the request value to a decrease in speed compared to a situation where no second correction process is performed. During the execution of the first correction process, if the driving assistance device requests emergency braking of the vehicle, the correction unit reduces the correction amount of the request value in the first correction process compared to a situation where emergency braking is not requested.

[0005] Other embodiments of this disclosure provide a vehicle control method that automatically adjusts the vehicle's speed based on a requested value input from a driving assistance device. This vehicle control method includes performing a first correction process on the requested value when the vehicle is traveling uphill, and performing a second correction process on the requested value when the vehicle is traveling downhill. The first correction process corrects the requested value to an increase in speed compared to a situation where no first correction process is performed. The second correction process corrects the requested value to a decrease in speed compared to a situation where no second correction process is performed. The first correction process includes reducing the correction amount of the requested value when the driving assistance device requests emergency braking of the vehicle, compared to a situation where emergency braking is not requested. Attached Figure Description

[0006] Figure 1 This is a schematic diagram showing the general structure of a vehicle equipped with driving control devices.

[0007] Figure 2 yes Figure 1 A block diagram of the driving control device.

[0008] Figure 3 yes Figure 2 Block diagram of the actual acceleration calculation unit and the slope resistance calculation unit of the driving control device.

[0009] Figure 4 This is an explanation Figure 2 A flowchart of the processing flow implemented by the feedforward correction unit of the driving control device.

[0010] Figure 5 This is a block diagram of the slope resistance calculation unit of the driving control device in the modified example. Detailed Implementation

[0011] Hereinafter, an embodiment in which the vehicle control device is embodied as a driving control device will be described with reference to the accompanying drawings. In this embodiment, the vehicle equipped with the driving control device is an electric vehicle.

[0012] <Vehicle 10>

[0013] like Figure 1 As shown, the vehicle 10 includes wheels 20, braking mechanism 30, drive unit 40, braking device 50, driving assistance device 60, driving control device 100, wheel speed sensor SE1, and front and rear acceleration sensor SE2. Figure 1 A diagram of some of the constituent elements of vehicle 10 is omitted.

[0014] <Brake Mechanism 30>

[0015] The braking mechanism 30 has a rotating body 31 that rotates integrally with the wheel 20, a friction element 32 that does not rotate integrally with the wheel 20, and a wheel cylinder 33 that displaces the friction element 32 toward the rotating body 31 according to hydraulic pressure.

[0016] The higher the hydraulic pressure in wheel cylinder 33, the stronger the braking mechanism 30 presses the friction element 32 against the rotating body 31. Furthermore, the greater the force with which the braking mechanism 30 presses the friction element 32 against the rotating body 31, the greater the frictional braking force Fbf applied to the wheel 20. A braking mechanism 30 is provided for each wheel 20. For example, in the case of a four-wheeled vehicle 10, the vehicle 10 has four braking mechanisms 30 corresponding to the four wheels 20.

[0017] <Driver 40>

[0018] The drive unit 40 includes an electric generator 41 and a drive control unit 42 for controlling the electric generator 41.

[0019] When the electric generator 41 functions as an electric motor, it supplies a driving force Fd to the wheels 20 to propel the vehicle 10. In this case, the electric generator 41 functions as the power source for the vehicle 10. The drive control unit 42 generates the driving force Fd from the electric generator 41 based on the required driving force Fdq requested from the driving control device 100. For example, if the vehicle 10 is a four-wheeled vehicle, it only needs to have an electric generator for the front wheels and an electric generator for the rear wheels.

[0020] <Brake device 50>

[0021] The braking device 50 has a brake actuator 51 for adjusting the hydraulic pressure of the wheel cylinder 33 and a brake control unit 52 for controlling the brake actuator 51.

[0022] The brake actuator 51 adjusts the hydraulic pressure of the wheel cylinders 33 by adjusting the amount of brake fluid supplied to them. Preferably, the brake actuator 51 can independently adjust the hydraulic pressure of the number of wheel cylinders 33 corresponding to the wheel 20. The brake control unit 52 generates a friction braking force Fbf in the brake actuator 51 based on the required braking force Fbq requested from the driving control device 100.

[0023] <Driving Assist Device 60>

[0024] The driver assistance device 60 performs automatic driving control to enable the vehicle 10 to drive automatically as a driver assistance function. For example... Figure 1 as well as Figure 2As shown, the driver assistance device 60 calculates the required value Rc for automated driving control based on various driving information. In this embodiment, the required value Rc represents the required value of the forward and backward force acting on the vehicle 10 in the forward and backward direction. When the required value Rc is positive, it indicates that the driver assistance device 60 requires the vehicle 10 to accelerate; when the required value Rc is negative, it indicates that the driver assistance device 60 requires the vehicle 10 to decelerate. Furthermore, the driving information includes, for example, information related to the position of the vehicle 10, information related to the surroundings of the vehicle 10, and information related to the driving state of the vehicle 10.

[0025] In addition, the driver assistance device 60 also has other driver assistance functions besides automatic driving control. One such function is emergency braking. Emergency braking is a function that requires the vehicle 10 to brake in order to avoid collisions with obstacles such as pedestrians or other vehicles in front of the vehicle 10. In this disclosure, braking performed by the braking device 50 when the braking force Fb required by the driving control device 100 for the vehicle 10 is higher than a predetermined threshold is referred to as "emergency braking." Emergency braking includes braking performed during the execution of emergency braking to avoid collisions with obstacles.

[0026] <Travel Control Device 100>

[0027] like Figure 2 As shown, the driving control device 100 includes a vehicle speed calculation unit 101, an actual acceleration calculation unit 102, a target acceleration calculation unit 103, an acceleration deviation calculation unit 104, a slope resistance calculation unit 105, a correction unit 106, and a front and rear force control unit 107. The driving control device 100 automatically adjusts the driving speed of the vehicle 10 by controlling the drive unit 40 and the braking unit 50 based on the required value Rc input from the driving assistance device 60. In the following description, the driving speed of the vehicle 10 is sometimes referred to as "vehicle speed Vb".

[0028] The vehicle speed calculation unit 101 calculates the wheel speed Vw based on the detection results of the wheel speed sensor SE1. The vehicle speed calculation unit 101 calculates the vehicle body speed Vb of the vehicle 10 based on the wheel speed Vw.

[0029] like Figure 3As shown, the actual acceleration calculation unit 102 calculates the actual acceleration Ga of the vehicle 10. The actual acceleration calculation unit 102 performs a process to calculate the acceleration by differentiating the vehicle velocity Vb calculated by the vehicle velocity calculation unit 101; that is, an acceleration calculation process. Hereinafter, the acceleration obtained through this calculation process will be referred to as the "calculated acceleration Ge". When the wheel velocity Vw changes significantly in a short time, such as when the wheel 20 slips, the calculated acceleration Ge can easily become a value that deviates from the actual acceleration of the vehicle 10. Therefore, the actual acceleration calculation unit 102 extracts only the low-frequency components of the calculated acceleration Ge by passing it through a low-pass filter LPF.

[0030] The actual acceleration calculation unit 102 acquires acceleration based on the detection results of the front and rear acceleration sensors SE2. Hereinafter, the acceleration acquired here will be referred to as "detected acceleration Gx". When the vehicle 10 is on a slope, the front and rear acceleration sensors SE2 are tilted relative to the horizontal direction, so the output values ​​of the front and rear acceleration sensors SE2 deviate from the values ​​corresponding to the slope of the road surface. Therefore, the actual acceleration calculation unit 102 extracts only the high-frequency components of the detected acceleration Gx by passing the calculated acceleration Ge through a high-pass filter HPF.

[0031] Furthermore, the actual acceleration calculation unit 102 calculates the actual acceleration Ga based on the value of the calculated acceleration Ge after passing it through a low-pass filter LPF and the value of the detected acceleration Gx after passing it through a high-pass filter HPF. For example, the actual acceleration calculation unit 102 uses the sum of the two values ​​as the actual acceleration Ga. In this way, the high-frequency components of the calculated acceleration Ge, which are removed by the low-pass filter LPF, are supplemented by the high-frequency components of the detected acceleration Gx, and the low-frequency components of the calculated acceleration Ge, which are removed by the high-pass filter HPF, are supplemented by the low-frequency components of the detected acceleration Gx, which are removed by the high-pass filter HPF.

[0032] like Figure 2 As shown, the target acceleration calculation unit 103 calculates the target acceleration Gt of the vehicle 10 based on the required value Rc from the driving assistance device 60. Specifically, the target acceleration calculation unit 103 calculates the target acceleration Gt based on the required value Rc, which is the front-to-rear force, and the mass of the vehicle 10. When the vehicle 10 is required to accelerate, the target acceleration Gt is positive; when the vehicle 10 is required to decelerate, the target acceleration Gt is negative.

[0033] The acceleration deviation calculation unit 104 calculates the acceleration deviation hG by subtracting the actual acceleration Ga calculated by the actual acceleration calculation unit 102 from the target acceleration Gt calculated by the target acceleration calculation unit 103.

[0034] like Figure 3As shown, the slope resistance calculation unit 105 calculates the slope resistance Rn of the road surface on which the vehicle 10 travels. In detail, the slope resistance calculation unit 105 performs front and rear force calculation processing, rolling resistance calculation processing, air resistance calculation processing, and slope resistance calculation processing.

[0035] The front and rear force calculation processing obtains the front and rear force Fq calculated by the front and rear force control unit 107. The front and rear force Fq is the required driving force Fdq and the required braking force Fbq calculated by the front and rear force control unit 107.

[0036] The rolling resistance calculation process calculates the rolling resistance Rr acting on vehicle 10. For example, the rolling resistance calculation process calculates the product of the vehicle 10's own weight and the rolling resistance coefficient of the wheel 20 as the rolling resistance Rr. The vehicle 10's own weight is the product of its mass and gravitational acceleration. Therefore, the greater the own weight, the greater the rolling resistance Rr. The rolling resistance Rr acts in the opposite direction to the vehicle 10's direction of travel, so it takes a negative value when the vehicle 10 is moving forward.

[0037] The air resistance calculation process applies to the air resistance Ra of vehicle 10. Air resistance Ra is calculated based on the vehicle's speed Vb, the total projected area of ​​vehicle 10, air density, and the drag coefficient. For example, the greater the vehicle speed Vb, the greater the air resistance Ra. Air resistance Ra acts in the opposite direction to the vehicle 10's direction of travel, so it takes a negative value when the vehicle 10 is moving forward.

[0038] The slope resistance calculation is based on the equation of motion representing the relationship between the force acting on vehicle 10 and the acceleration of vehicle 10. Specifically, the slope resistance Rn is calculated by solving the following equation. In the following equation, "m" represents the mass of vehicle 10.

[0039] Fq+Rn+Rr+Ra=m·Ga

[0040] The slope resistance Rn is the force acting on vehicle 10 due to the gradient of the road surface. In other words, the slope resistance Rn is the product of the mass of vehicle 10 and the acceleration due to gravity, that is, the component of vehicle 10's weight along the road surface. When vehicle 10 is moving uphill, the slope resistance Rn is negative; when vehicle 10 is moving downhill, the slope resistance Rn is positive. Conversely, when vehicle 10 is moving backward uphill, the slope resistance Rn is positive; when vehicle 10 is moving backward downhill, the slope resistance Rn is negative. Furthermore, the greater the absolute value of the gradient of the road surface relative to a surface perpendicular to the direction of gravity, the greater the absolute value of the slope resistance Rn. On the other hand, when vehicle 10 is traveling on a level road, the slope resistance Rn is "0".

[0041] like Figure 2 As shown, the correction unit 106 includes a feedback correction unit 111, a feedforward correction unit 112, and a conversion unit 113.

[0042] The feedback correction unit 111 calculates the feedback correction amount Si for reducing the deviation hG. That is, the feedback correction amount Si is a value calculated by feedback control using the deviation hG as input. For example, the feedback control includes proportional control and integral control. In this case, the feedback correction amount Si becomes the value obtained by adding the product of the proportional gain and the deviation hG, and the product of the integral gain and the time integral of the deviation hG. Furthermore, the feedback control may also include derivative control.

[0043] The conversion unit 113 converts the feedback correction amount Si calculated by the feedback correction unit 111 into a quantity with the same dimensions as the required value Rc. In this embodiment, the conversion unit 113 converts the feedback correction amount Si, which is in the dimension of acceleration, into a feedback correction amount in the dimension of forward and backward force. In the following description, the converted feedback correction amount will also be referred to as the "feedback correction amount Rh". The feedback correction amount Rh is used to correct the value of the required value Rc by adding it to the required value Rc.

[0044] The feedforward correction unit 112 calculates the feedforward correction amount Rf corresponding to the slope resistance Rn. The feedforward correction amount Rf corrects the value of the required value Rc by adding it to the required value Rc. Therefore, the feedforward correction amount Rf has the same dimensions as the required value Rc.

[0045] The feedforward correction unit 112 determines whether the road surface on which the vehicle 10 is traveling is uphill or downhill based on the magnitude of the slope resistance Rn. When the slope resistance Rn is less than the uphill determination value Rn1, the feedforward correction unit 112 determines that the vehicle 10 is traveling uphill. The uphill determination value Rn1 is a reference used to determine whether the road surface is uphill using the slope resistance Rn. The uphill determination value Rn1 is set to "0" or a value slightly smaller than "0". On the other hand, when the slope resistance Rn is greater than the downhill determination value Rn2, the feedforward correction unit 112 determines that the vehicle 10 is traveling downhill. The downhill determination value Rn2 is a reference used to determine whether the road surface is downhill using the slope resistance Rn. The downhill determination value Rn2 is set to "0" or a value slightly larger than "0".

[0046] When the vehicle 10 is traveling uphill, the feedforward correction unit 112 performs a first correction process. In this first correction process, the feedforward correction unit 112 sets the feedforward correction amount Rf to a positive value. The steeper the gradient of the uphill road, i.e., the greater the slope resistance Rn, the more the feedforward correction unit 112 increases the feedforward correction amount Rf. Then, the required value Rc is increased by adding the feedforward correction amount Rf to the required value Rc. If the required value Rc is increased during vehicle 10 acceleration, the acceleration of vehicle 10 increases. If the required value Rc is increased during vehicle 10 deceleration, the deceleration of vehicle 10 decreases. Therefore, when the first correction process is performed, the vehicle speed increases compared to the case where the first correction process is not performed.

[0047] On the other hand, when the vehicle 10 is traveling downhill, the feedforward correction unit 112 performs a second correction process. In the second correction process, the feedforward correction unit 112 sets the feedforward correction amount Rf to a negative value. The steeper the gradient of the downhill road, that is, the smaller the slope resistance Rn, the more the feedforward correction unit 112 reduces the feedforward correction amount Rf. Then, the required value Rc is reduced by adding the feedforward correction amount Rf to the required value Rc. If the required value Rc is reduced during the acceleration of the vehicle 10, the acceleration of the vehicle 10 decreases. If the required value Rc is reduced during the deceleration of the vehicle 10, the deceleration of the vehicle 10 increases. That is, if the second correction process is performed, the travel speed of the vehicle 10 decreases compared to the case where the second correction process is not performed.

[0048] Furthermore, both the first and second correction processes are essentially the same in that they add the feedforward correction amount Rf corresponding to the slope resistance Rn to the required value Rc. The difference between the first and second correction processes lies in the sign of the feedforward correction amount Rf added to the required value Rc.

[0049] By performing the first correction process and the second correction process, the greater the absolute value of the gradient of the road surface on which the vehicle 10 travels, the greater the absolute value of the feedforward correction amount Rf. In order to establish a correlation between the absolute value of the feedforward correction amount Rf and the absolute value of the gradient of the road surface on which the vehicle 10 travels, the feedforward correction unit 112 can set the value of the slope resistance Rn after reversing its positive and negative values ​​as the feedforward correction amount Rf.

[0050] Therefore, when vehicle 10 is traveling uphill, in other words, when the slope resistance Rn acts as a force that decelerates vehicle 10, the feedforward correction Rf becomes a force that accelerates vehicle 10. Similarly, when vehicle 10 is traveling downhill, in other words, when the slope resistance Rn acts as a force that accelerates vehicle 10, the feedforward correction Rf becomes a force that decelerates vehicle 10. Thus, the feedforward correction Rf can also be considered a force that counteracts the slope resistance Rn.

[0051] However, when the driver assistance device 60 performs driver assistance functions such as automatic driving control to automatically adjust the vehicle speed Vb, for example, if another vehicle suddenly cuts in front of the vehicle 10, it executes a driver assistance function requiring emergency braking. In this case, the driver assistance device 60 outputs a request value Rc for emergency braking to the driving control device 100. In this situation, the request value Rc is negative and has a large absolute value. When executing the driver assistance function requiring emergency braking, it is preferable to stop the vehicle 10 quickly. However, if the vehicle 10 is traveling uphill and the feedforward correction Rf is positive, the force used to decelerate the vehicle 10 is reduced. Therefore, when the vehicle 10 is traveling uphill and an emergency braking of the vehicle 10 is required, it is preferable to reduce the feedforward correction Rf.

[0052] Therefore, when performing the first correction process, the feedforward correction unit 112 reduces the feedforward correction amount Rf when the driver assistance device 60 requests emergency braking of the vehicle 10, compared to the case where emergency braking of the vehicle 10 is not requested. Consequently, the correction amount of the requested value Rc based on the feedforward correction amount Rf in the first correction process becomes smaller. In this embodiment, even when performing the first correction process, the feedforward correction unit 112 sets the feedforward correction amount Rf to "0" when emergency braking of the vehicle 10 is requested.

[0053] Furthermore, the feedforward correction unit 112 determines whether to require the vehicle 10 to brake suddenly based on whether the required value Rc is less than the emergency braking required value Rchb. The emergency braking required value Rchb is a negative value and corresponds to the magnitude of the braking force Fb applied to the vehicle 10 when it brakes suddenly. If the value of the braking force Fb corresponding to the emergency braking required value Rchb is defined as a predetermined judgment value, then when the required value Rc is less than the emergency braking required value Rchb, the required braking force Fbq from the driver assistance device 60 to the driving control device 100 is higher than the predetermined judgment value.

[0054] On the other hand, when the vehicle 10 is traveling downhill, the feedforward correction amount Rf takes a negative value. Therefore, when the vehicle 10 is traveling downhill, the feedforward correction unit 112 does not perform correction based on the feedforward correction amount Rf that requires the vehicle 10 to brake suddenly.

[0055] The front and rear force control unit 107 controls the drive unit 40 and the braking unit 50 based on the sum of the required value Rc, the feedback correction amount Rh, and the feedforward correction amount Rf (hereinafter also referred to as the "corrected required value Rt"). For example, when the corrected required value Rt is positive, the front and rear force control unit 107 requests a required driving force Fdq from the drive unit 40 corresponding to the magnitude of the corrected required value Rt. In this case, a driving force Fd corresponding to the required driving force Fdq is applied to the vehicle 10. On the other hand, when the corrected required value Rt is negative, the front and rear force control unit 107 requests a required braking force Fbq from the braking unit 50 corresponding to the magnitude of the corrected required value Rt. In this case, a friction braking force Fbf corresponding to the required braking force Fbq is applied to the vehicle 10.

[0056] As described above, the slope resistance calculation unit 105 calculates the slope resistance Rn using the required driving force Fdq and required braking force Fbq calculated by the front and rear force control unit 107. However, the required driving force Fdq during the calculation of slope resistance Rn may deviate from the driving force Fd applied to the vehicle 10 by the electric generator 41 due to the responsiveness of the electric generator 41. Similarly, the required braking force Fbq during the calculation of slope resistance Rn may deviate from the friction braking force Fbf applied to the vehicle 10 by the brake actuator 51 due to the responsiveness of the brake actuator 51. Therefore, it is preferable that the slope resistance calculation unit 105 considers the responsiveness of the electric generator 41 and the brake actuator 51 when calculating the slope resistance Rn. For example, it is preferable that the slope resistance calculation unit 105 calculates the slope resistance Rn based on the values ​​after a gradual processing such as a delay processing on the required driving force Fdq and required braking force Fbq calculated by the front and rear force control unit 107.

[0057] Furthermore, the slope resistance calculation unit 105 can also calculate the slope resistance Rn without using the required driving force Fdq and the required braking force Fbq. For example, when the hydraulic pressure of the wheel cylinder 33 can be detected, the slope resistance calculation unit 105 can also obtain the braking force Fb acting on the vehicle 10 based on the hydraulic pressure of the wheel cylinder 33. Moreover, the slope resistance calculation unit 105 can use the braking force Fb instead of the required braking force Fbq to calculate the slope resistance Rn. When the current value flowing through the electric generator 41 can be detected, the slope resistance calculation unit 105 can also obtain the driving force Fd acting on the vehicle 10 based on the current value. Moreover, the slope resistance calculation unit 105 can use the driving force Fd instead of the required driving force Fdq to calculate the slope resistance Rn.

[0058] Next, refer to Figure 4The flowchart shown illustrates the process performed by the feedforward correction unit 112 when calculating the feedforward correction amount Rf. This process is performed at predetermined control cycles during the operation of the vehicle 10.

[0059] like Figure 4 As shown, the feedforward correction unit 112 determines whether the slope resistance Rn calculated by the slope resistance calculation unit 105 is greater than the downhill determination value Rn2 (S11). If the slope resistance Rn is greater than the downhill determination value Rn2 (S11: Yes), in other words, when the vehicle 10 is traveling downhill, the feedforward correction unit 112 calculates the feedforward correction amount Rf corresponding to the slope resistance Rn (S12). Thereafter, the feedforward correction unit 112 ends this process.

[0060] In step S11, if the slope resistance Rn is below the downhill determination value Rn2, the feedforward correction amount Rf determines whether the slope resistance Rn is smaller than the uphill determination value Rn1 (S13). If the slope resistance Rn is smaller than the uphill determination value Rn1 (S13: Yes), the feedforward correction unit 112 determines whether the required value Rc is less than the emergency braking required value Rchb (S14). If the required value Rc is greater than the emergency braking required value Rchb (S14: No), in other words, if the driver assistance device 60 does not request emergency braking of the vehicle 10, the feedforward correction unit 112 moves the processing to step S12. In this case, the feedforward correction amount Rf corresponding to the slope resistance Rn is calculated.

[0061] In step S14, if the required value Rc is less than the emergency braking required value Rchb (S14: Yes), in other words, when the driver assistance device 60 requests emergency braking of the vehicle 10, the feedforward correction unit 112 sets the feedforward correction amount Rf to "0" (S15). Thereafter, the feedforward correction unit 112 ends the process. Alternatively, in step S13, if the slope resistance Rn is greater than the uphill determination value Rn1 (S13: No), that is, when the vehicle 10 is traveling on a level road, the feedforward correction unit 112 moves the process to step S15. In this case, since the vehicle 10 is not traveling on a slope, the feedforward correction amount Rf is "0".

[0062] <The function and effects of this implementation method>

[0063] When vehicle 10 is traveling uphill and downhill, the required value Rc is corrected in the first and second correction processes based on the feedforward correction amount Rf corresponding to the slope resistance Rn. Specifically, when vehicle 10 is traveling uphill, the feedforward correction amount Rf becomes a value greater than 0, and when vehicle 10 is traveling downhill, the feedforward correction amount Rf becomes a value less than 0. That is, when vehicle 10 is traveling uphill, the required value Rc is increased through the first correction process to calculate the corrected required value Rt. On the other hand, when vehicle 10 is traveling downhill, the required value Rc is decreased through the second correction process to calculate the corrected required value Rt. Since the drive unit 40 and braking unit 50 drive based on this corrected required value Rt, it is possible to suppress the actual acceleration Ga of vehicle 10 from deviating from the target acceleration Gt corresponding to the required value Rc of driving assistance device 60.

[0064] However, even when vehicle 10 is traveling uphill, if the driver assistance device 60 requests emergency braking of vehicle 10, the feedforward correction amount Rf used in the first correction process is set to "0". That is, compared to the case where emergency braking is not requested, the correction amount of the requested value Rc in the first correction process is smaller. In this case, the braking force Fb corresponding to the requested value Rc and the slope resistance Rn, which act as the force to decelerate vehicle 10, are applied to vehicle 10. In other words, the increase in the force to decelerate vehicle 10 reduces the amount of feedforward correction Rf. Therefore, vehicle 10 stops quickly.

[0065] On the other hand, when the vehicle 10 is traveling downhill, even if the driving assistance device 60 requires the vehicle 10 to brake suddenly, the feedforward correction Rf does not become "0". Therefore, it is possible to quickly stop the vehicle 10 while making the actual acceleration Ga follow the target acceleration Gt.

[0066] <Example of Change>

[0067] This embodiment can be implemented with modifications as follows. This embodiment and the following modifications can be combined with each other within the scope of technical inconsistency.

[0068] • The driving control device 100 can also be replaced Figure 2 The slope resistance calculation unit 105 shown is equipped with... Figure 5The slope resistance calculation unit 108 is shown. The slope resistance calculation unit 108 calculates the slope resistance Rn by performing acceleration calculation processing, road gradient calculation processing, and slope resistance calculation processing. The acceleration calculation processing calculates the acceleration Ge in the same way as the actual acceleration calculation unit 102 in the above embodiment. The road gradient calculation processing calculates the gradient of the road surface on which the vehicle 10 travels (hereinafter also referred to as "road gradient θ") based on the calculated acceleration Ge and the detected acceleration Gx. Here, the road gradient θ takes a positive value when going uphill and a negative value when going downhill. Furthermore, the slope resistance calculation processing calculates the slope resistance Rn based on the mass of the vehicle 10, gravitational acceleration, and road gradient.

[0069] The feedforward correction unit 112 can also set the feedforward correction amount Rf to a constant value regardless of the gradient of the uphill road when the vehicle 10 is traveling uphill. Alternatively, the feedforward correction unit 112 can also set the feedforward correction amount Rf to a stepped value corresponding to the gradient of the uphill road when the vehicle 10 is traveling uphill. The same applies when the vehicle 10 is traveling downhill.

[0070] The feedforward correction unit 112 can also calculate the feedforward correction amount Rf by multiplying the value after reversing the positive and negative values ​​of the slope resistance Rn by a coefficient of "0 to 1". In this case, it is preferable that the feedforward correction unit 112 reduces the above coefficient when emergency braking is required compared to when emergency braking is not required. As an example, if the feedforward correction unit 112 sets the above coefficient to "0.1" when emergency braking is required, the feedforward correction amount Rf becomes one-tenth of its original value.

[0071] The required value Rc of the driving assistance device 60 can be any value related to the front and rear forces. For example, the required value Rc of the driving assistance device 60 can also be acceleration. In this case, the target acceleration calculation unit 103 can be omitted from the driving control device 100 since it does not need to calculate the target acceleration Gt, and the conversion unit 113 can also be omitted since it does not need to make the dimensions of the feedback correction amount Si consistent.

[0072] • The driving assistance device 60 can also be divided into a device responsible for automatic driving control and a device responsible for emergency braking control. In this case, the driving control device 100 can also determine whether to request emergency braking of the vehicle 10 based on whether it has received a signal requesting emergency braking from the device responsible for emergency braking control.

[0073] • The drive unit 40 may also be a device equipped with an internal combustion engine. In this case, the slope resistance calculation unit 105 can also obtain the driving force Fd acting on the vehicle 10 based on the throttle valve opening and engine speed. Moreover, the slope resistance calculation unit 105 can also use the driving force Fd to calculate the slope resistance Rn.

[0074] Alternatively, a regenerative braking force Fbr can be applied to the wheels 20 via an electric generator 41 to decelerate the vehicle 10. In this case, it is preferable that the driving control device 100 controls the drive device 40 and the braking device 50 such that the sum of the regenerative braking force Fbr and the friction braking force Fbf becomes the required braking force Fbq.

[0075] The braking device 50 can also be an electric braking device (EMB: Electro Mechanical Brake).

[0076] The number of wheels 20 on vehicle 10 is arbitrary. For example, vehicle 10 can be either a two-wheeled vehicle or a four-wheeled vehicle.

[0077] The driving control device 100 is not limited to a processing circuit that includes a CPU and ROM and performs software processing. For example, the driving control device 100 may also include dedicated hardware circuitry that performs at least a portion of the various processes executed in the above embodiments. Examples of dedicated hardware circuitry include ASICs. ASIC stands for "Application Specific Integrated Circuit". That is, the driving control device 100 can be configured as any of the following (a) to (c).

[0078] (a) A processing circuit having all the processing devices that perform the above processing according to the program, and a program storage device such as a ROM that stores the program.

[0079] (b) A processing circuit having a processing device that performs a portion of the above-described processing according to a program, a program storage device, and dedicated hardware circuitry for performing the remaining processing.

[0080] (c) A processing circuit that has all the dedicated hardware circuits to perform the above processing.

[0081] Here, there may be multiple software execution devices with processing devices and program storage devices, as well as dedicated hardware circuits.

Claims

1. A vehicle control device that automatically adjusts the vehicle's speed based on a required value input from a driving assistance device, wherein, The vehicle is equipped with a correction unit that performs a first correction process on the required value when the vehicle is traveling uphill, and a second correction process on the required value when the vehicle is traveling downhill. The first correction process described above corrects the required value to an increase in driving speed compared to the case where no first correction process is performed. The second correction process described above corrects the required value to a level that reduces the driving speed compared to the case where no second correction process is performed. In executing the first correction process, the correction unit reduces the correction amount of the requested value in the first correction process when the driving assistance device requests emergency braking of the vehicle, compared to when the vehicle is not requested to brake suddenly. The aforementioned vehicle control device also includes a slope resistance calculation unit, which calculates the slope resistance corresponding to the gradient of the road surface on which the vehicle travels. The aforementioned correction unit includes a feedforward correction unit that calculates a feedforward correction amount corresponding to the aforementioned slope resistance, and performs the aforementioned first correction process and the aforementioned second correction process using the aforementioned feedforward correction amount. When the vehicle is traveling uphill and performing the first correction process, if the driving assistance device requests the vehicle to brake suddenly, the feedforward correction unit increases the force that decelerates the vehicle by reducing the correction amount based on the requested value in the first correction process, compared to when no sudden braking request is made. When the vehicle is traveling downhill and performing the second correction process, the feedforward correction unit does not make corrections to the feedforward correction amount based on the situation where the driving assistance device requests the vehicle to brake suddenly.

2. The vehicle control device according to claim 1, wherein, The aforementioned slope resistance calculation unit calculates the slope resistance based on the relationship between the front and rear forces acting on the vehicle and the vehicle's actual acceleration. The aforementioned front and rear forces include the driving force that accelerates the vehicle, the braking force that decelerates the vehicle, and the slope resistance.

3. The vehicle control device according to claim 2, wherein, The aforementioned front and rear forces also include at least one of the air resistance acting on the vehicle and the rolling resistance of the vehicle's wheels.

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