Vehicular control device

Abstract

To provide a vehicular control device, which can suppress an error of an estimated gradient value from occurring.SOLUTION: A vehicular control device according to the present invention is provided with: a gradient estimating part that estimates a gradient of a road surface on which an own vehicle is positioned, on the basis of predetermined sensor data and outputs an estimated gradient value; a calculating part that calculates gradient-change amounts, on the basis of the estimated gradient value lastly outputted and an estimated gradient value outputted this time; and a guard processing part that compares the gradient change amounts with a threshold, does not correct the estimated gradient value when the gradient change amounts are less than the threshold, and executes a guard process for correcting the estimated gradient value in accordance with the gradient change amounts, when the gradient change amounts are above or equal to the threshold.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a vehicle control device. [Background technology]

[0002] Conventionally, in vehicles (passenger cars, etc.), road surface gradients are estimated based on predetermined sensor data. For example, a gradient estimate is calculated using the longitudinal acceleration of the vehicle obtained from an acceleration sensor and the vehicle acceleration calculated based on data obtained from wheel speed sensors. The calculated gradient estimate is used for various controls. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-123719 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the conventional technology, for example, when the vehicle starts moving from a stopped state, or when the driver suddenly accelerates or brakes while the vehicle is moving, the vehicle body may tilt, causing a large error in the gradient estimation value. This affects various controls, so improvements are needed.

[0005] Therefore, an object of the present invention is to provide a vehicle control device that can suppress errors in gradient estimation values. [Means for solving the problem]

[0006] In order to solve the above problems, the vehicle control device of the present invention includes a gradient estimation unit that estimates the gradient of the road surface on which the vehicle is located based on predetermined sensor data and outputs a gradient estimation value, a calculation unit that calculates a gradient change amount based on the previous gradient estimation value and the current gradient estimation value, and a guard processing unit that executes guard processing that compares the gradient change amount with a threshold value and does not correct the gradient estimation value if the gradient change amount is less than the threshold value, and corrects the gradient estimation value in accordance with the gradient change amount if the gradient change amount is equal to or greater than the threshold.

[0007] According to this configuration, when the amount of gradient change is equal to or greater than the threshold, the gradient estimated value is corrected in accordance with the amount of gradient change, thereby making it possible to suppress errors in the gradient estimated value.

[0008] In addition, in the vehicle control device, the guard processing unit executes the guard processing when the host vehicle starts from a stopped state, or when a sudden accelerator operation or a sudden braking operation is performed while the host vehicle is traveling.

[0009] According to this configuration, the guard process can be executed only when the host vehicle starts moving, when the accelerator pedal is suddenly operated, or when the brakes are suddenly applied, which are times when the error in the gradient estimation value is likely to become large.

[0010] In the vehicle control device, the guard processing unit executes the guard processing when sudden acceleration suppression control is activated in the host vehicle.

[0011] According to this configuration, the guard process can be executed when the sudden acceleration suppression control is activated, which requires a more accurate gradient estimation value.

[0012] In the vehicle control device, the threshold value is set individually according to the vehicle speed of the host vehicle and the unevenness of the road surface on which the host vehicle is positioned.

[0013] According to this configuration, by using individual threshold values ​​according to the vehicle speed of the host vehicle and the distinction between unevenness of the road surface, it is possible to realize guard processing with higher accuracy. Effect of the Invention

[0014] According to the present invention, an error in a gradient estimation value can be suppressed in a vehicle control device. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a block diagram showing a part of the configuration of a vehicle according to an embodiment. [Diagram 2] FIG. 2 is a table showing threshold values ​​of gradient changes in the embodiment. [Diagram 3] FIG. 3 is a flowchart showing a process performed by the engine ECU according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a vehicle control device of the present invention will be described in detail with reference to the drawings.

[0017] 1 is a block diagram showing a part of the configuration of a vehicle 1 (host vehicle) according to an embodiment. The vehicle 1 is an automobile using an engine 2 as a drive source. The engine 2 is, for example, a gasoline engine, and includes an electronic throttle valve for adjusting the amount of intake air into a combustion chamber of the engine 2, an injector (fuel injection device) for injecting fuel into the intake air, and an ignition plug for generating an electrical discharge in the combustion chamber.

[0018] Power of the engine 2 is transmitted to left and right drive wheels via the transmission 3. The transmission 3 has a range of gear shifts including, for example, a P range, a R range, a N range, and a D range. To instruct switching of the gear shift range, a shift lever (select lever) is provided in the passenger compartment of the vehicle 1. The movable range of the shift lever has a P position, an R position, a N position, and a D position set corresponding to the gear shift ranges.

[0019] The vehicle 1 is provided with a starter motor 4 for cranking the engine 2, and an alternator 5 for generating electricity by the rotation of the engine 2. The vehicle 1 is also equipped with a battery 6 consisting of a 12V (volt) lead battery.

[0020] The rotation of the output shaft of the engine 2 is transmitted to the rotating shaft of the alternator 5. When the rotating shaft of the alternator 5 rotates, the rotation is converted into electric power, and the electric power is output from the alternator 5. The electric power output from the alternator 5 is supplied to the battery 6, whereby the battery 6 is charged.

[0021] Additionally, an accelerator pedal operated to accelerate or decelerate the vehicle 1, and a brake pedal operated to brake the vehicle 1 are provided under the driver's seat within the vehicle cabin 1. The accelerator pedal and the brake pedal are located at positions convenient for the driver to step on with his / her right foot while seated in the driver's seat.

[0022] The vehicle 1 is also equipped with a hydraulic brake 8. The hydraulic brake 8 includes a brake booster 9, a master cylinder, a brake actuator, and the like. When the brake pedal is depressed, the depression force input to the brake pedal is transmitted to the brake booster 9. The brake booster 9 is supplied with a negative pressure generated by the drive of the engine 2. The depression force transmitted to the brake booster 9 is amplified (doubled) by the negative pressure of the brake booster 9, and is input from the brake booster 9 to the master cylinder. The master cylinder generates hydraulic pressure according to the force input from the brake booster 9. The hydraulic pressure generated by the master cylinder is transmitted to the brake actuator. Then, by the function of the brake actuator, hydraulic pressure is distributed to the wheel cylinders of the brakes provided on each wheel, and the hydraulic pressure applies a braking force from each brake to the wheels including the drive wheels.

[0023] The vehicle 1 is equipped with an ECU (Electronic Control Unit) including a microcontroller (microcontroller unit). The microcontroller includes, for example, a CPU (Central Processing Unit), a non-volatile memory such as a flash memory, and a volatile memory such as a DRAM (Dynamic Random Access Memory). The vehicle 1 is equipped with a plurality of ECUs for controlling each part. The plurality of ECUs are connected to enable two-way communication by a CAN (Controller Area Network) communication protocol. The plurality of ECUs includes an engine ECU 11 (vehicle control device) and a brake ECU 12.

[0024] The engine ECU 11 is a control unit that executes control of starting / stopping the engine 2, output adjustment control, and control of the gear ratio of the transmission 3. An accelerator sensor 21, a brake negative pressure sensor 22, a shift range switch 23, a wheel speed sensor 24, and a G sensor 31 are connected to the engine ECU 11.

[0025] The accelerator sensor 21 outputs a detection signal corresponding to the amount of accelerator pedal operation. The brake negative pressure sensor 22 outputs a detection signal corresponding to the negative pressure of the brake booster 9. The shift range switch 23 outputs a detection signal corresponding to the shift range (shift lever position) configured in the transmission 3.

[0026] The wheel speed sensor 24 outputs a detection signal (wheel speed pulse) corresponding to the wheel speed of the vehicle 1. The G sensor 31 outputs a detection signal corresponding to the acceleration of the vehicle 1 in the forward / rearward direction.

[0027] The engine ECU 11 includes, as functional components, an acquisition unit 111, a gradient estimation unit 112, a calculation unit 113, a guard processing unit 114, a control unit 115, and a storage unit .

[0028] The storage unit 116 stores information such as various programs, various sensor data, and various calculation results.

[0029] The acquisition unit 111 acquires data from various sensors, various switches, and the like.

[0030] The gradient estimation unit 112 estimates the gradient of the road surface on which the vehicle 1 is located based on predetermined sensor data, and outputs a gradient estimation value. Specifically, this is as follows.

[0031] The acceleration obtained from the detection signal of the G sensor 31 includes an acceleration component due to changes in vehicle speed and an acceleration component due to the gradient of the road surface on which the vehicle 1 is located. On the other hand, the acceleration calculated by differentiating the vehicle speed obtained from the detection signal of the wheel speed sensor 24 includes only the acceleration component due to changes in vehicle speed. Therefore, the acceleration component due to the gradient of the road surface can be obtained by using the difference between the two, and the gradient of the road surface can be estimated based on the acceleration component.

[0032] The calculation unit 113 calculates the gradient change amount based on the previous gradient estimated value and the current gradient estimated value.

[0033] The guard processing unit 114 executes guard processing. In the guard processing, the guard processing unit 114 compares the gradient change amount calculated by the calculation unit 113 with a threshold value, and does not correct the gradient estimated value if the gradient change amount is less than the threshold value, and corrects the gradient estimated value according to the gradient change amount if the gradient change amount is equal to or greater than the threshold value.

[0034] When correcting the gradient estimate, the guard processing unit 114 corrects the gradient estimate so that, for example, the amount of gradient change in the corrected gradient estimate becomes less than a threshold value.

[0035] Moreover, the guard processing unit 114 may be configured to execute the guard processing only in the following three cases. (1) When vehicle 1 starts moving from a stopped state (2) When sudden acceleration or braking is performed while vehicle 1 is traveling (3) When the emergency accelerator suppression control (EAPM (Emergency Assist for Pedal Misapplication) control) is activated in vehicle 1

[0036] In addition, in the EAPM control, when the driver accidentally depresses the accelerator pedal suddenly, control according to the torque value (torque cut or torque suppression) is performed to prevent a sudden start. In that case, control is also performed to leave torque according to the gradient so that the vehicle 1 does not roll down on a sloped road surface (hill road). Therefore, in the EAPM control, a more accurate gradient estimation value is required.

[0037] Furthermore, the threshold value of the gradient change amount may be set individually depending on the speed of the vehicle 1 and the unevenness of the road surface on which the vehicle 1 is located. This will be described with reference to FIG.

[0038] Fig. 2 is a table showing the thresholds of gradient change in the embodiment. From the left, the following items are set: design speed, curve shape of the vertical curve, radius of the vertical curve, and threshold of gradient change. Note that the items other than the threshold of gradient estimation are the same as those in Article 22 of the Road Structure Ordinance established by the Ministry of Land, Infrastructure, Transport and Tourism.

[0039] Each row in this table has a different threshold value set, that is, when the gradient change amount is equal to or exceeds the threshold value under the conditions of each row, the gradient estimate is likely to contain an error, so the gradient estimate is corrected to an appropriate value by guard processing.

[0040] In this case, the guard processing unit 114 executes the guard processing using a corresponding threshold value depending on, for example, the vehicle speed calculated from various sensor data and the unevenness of the road surface on which the vehicle 1 is positioned.

[0041] For example, if the vehicle speed is "120 (km / h)" and the curve shape of the vertical curve is "convex curve", the threshold value of the gradient change amount is set to "0.001 (m / s 2For vehicle speed, the smallest design speed greater than the actual vehicle speed is used. In other words, if the actual vehicle speed is 90 km / h, the smallest design speed greater than 90 km / h is used.

[0042] In this way, by performing guard processing using a threshold value in accordance with the Road Structure Act, it is possible to prevent changes in the gradient estimate value that would not occur in a normal road environment.

[0043] 1, the control unit 115 executes various types of control. For example, in addition to controlling the engine 2, the control unit 115 cooperates with the brake ECU 12 to execute EAPM control.

[0044] The brake ECU 12 is a control unit that controls the brake actuators of the hydraulic brakes 8. The brake ECU 12 executes, for example, ABS (Antilock Brake System) control that intermittently brakes the wheels of the vehicle 1 to prevent the wheels from locking, attitude control that keeps the attitude of the vehicle 1 stable when braking or turning the vehicle 1, and brake hold control that maintains a braking state (stopped state) even if the foot is released from the brake pedal when the vehicle 1 is stopped.

[0045] The brake ECU 12 is connected to a brake sensor 25 that outputs a detection signal corresponding to the amount of operation of a brake pedal, for example.

[0046] 3 is a flowchart showing the process performed by the engine ECU 11 in this embodiment. In step S1, the gradient estimation unit 112 estimates the gradient of the road surface on which the vehicle 1 is positioned based on predetermined sensor data, and outputs a gradient estimation value.

[0047] Next, in step S2, the calculation unit 113 calculates the gradient change amount based on the previous gradient estimated value and the current gradient estimated value.

[0048] Next, in step S3, the guard processing unit 114 compares the gradient change amount calculated in step S2 with a threshold value (for example, a threshold value according to the vehicle speed of the vehicle 1 and the unevenness of the road surface on which the vehicle 1 is located (Figure 2)), and if the answer is Yes, the process proceeds to step S4, and if the answer is No, the process ends (the gradient estimate value is not corrected).

[0049] In step S4, the guard processing unit 114 corrects the gradient estimate value in accordance with the gradient change amount.

[0050] In this way, according to this embodiment, when the gradient change amount is equal to or greater than the threshold, the gradient estimate value is corrected according to the gradient change amount, thereby suppressing errors in the gradient estimate value. In other words, it becomes possible to prevent the occurrence of gradient estimate values ​​that would not occur in normal road environments, and to perform highly accurate gradient estimation even in driving conditions where the vehicle behavior changes suddenly.

[0051] In addition, the guard process can be executed only when the vehicle 1 starts moving, when the accelerator pedal is suddenly operated, or when the brakes are suddenly operated, which are times when the error in the gradient estimation value is likely to become large. In this way, the process can be avoided in situations where the error in the gradient estimation value is unlikely to become large, that is, in situations where the need to correct the gradient estimation value is low.

[0052] Furthermore, by executing a guard process when EAPM control is activated, it is possible to prevent the vehicle 1 from rolling down a slope, for example.

[0053] Moreover, by using individual threshold values ​​(FIG. 2) according to the speed of the vehicle 1 and the distinction between unevenness of the road surface, it is possible to realize guard processing with higher accuracy.

[0054] In addition, the programs executed by each ECU such as the engine ECU 11 of this embodiment can be provided by recording them in an installable or executable format on a recording medium readable by a computer device, such as a CD (Compact Disc)-ROM (Read Only Memory), a flexible disk (FD), a CD-R (Recordable), or a DVD (Digital Versatile Disk). The programs may also be provided or distributed via a network such as the Internet.

[0055] Although an embodiment of the present invention has been described, this embodiment is presented as an example and is not intended to limit the scope of the invention. This novel embodiment can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. This embodiment and its modifications are included in the scope and spirit of the invention, and are included in the invention and its equivalents described in the claims.

[0056] For example, in the above embodiment, for the sake of simplicity, the guard process is executed only by the engine ECU 11. However, the guard process may be executed by the engine ECU 11 and the brake ECU 12 in cooperation with each other, or may be executed by another method.

[0057] Furthermore, the present invention can be applied to all situations where torque control is performed using a gradient estimate, such as ACC (Adaptive Cruise Control) in addition to EAPM control. [Explanation of symbols]

[0058] 1...vehicle, 2...engine, 11...engine ECU, 12...brake ECU, 111...acquisition unit, 112...gradient estimation unit, 113...calculation unit, 114...guard processing unit, 115...control unit, 116...storage unit

Claims

1. a gradient estimation unit that estimates a gradient of a road surface on which the host vehicle is located based on predetermined sensor data and outputs a gradient estimation value; a calculation unit that calculates a gradient change amount based on the previous gradient estimated value and the current gradient estimated value; a guard processing unit that executes guard processing to compare the gradient change amount with a threshold value, and not correct the gradient estimated value if the gradient change amount is less than the threshold value, and to correct the gradient estimated value in accordance with the gradient change amount if the gradient change amount is equal to or greater than the threshold value.

2. The vehicle control device according to claim 1 , wherein the guard processing unit executes the guard processing when the host vehicle starts from a stopped state, or when a sudden accelerator operation or a sudden braking operation is performed while the host vehicle is traveling.

3. The vehicle control device according to claim 1 , wherein the guard processing unit executes the guard processing when a sudden acceleration suppression control is activated in the host vehicle.

4. The vehicle control device according to claim 1 , wherein the threshold value is set individually depending on a vehicle speed of the host vehicle and a level of unevenness of a road surface on which the host vehicle is positioned.

Images