Vehicle control device

Abstract

The invention provides a vehicle control device capable of improving vehicle behavior stability. A vehicle control device includes a regenerative braking device and a friction braking device that apply regenerative braking force and friction braking force to wheels in a vehicle, and a control device that controls the regenerative braking force and the friction braking force based on a demand braking force. The control device is provided with: an anti-lock control unit that executes first prevention control for preventing the wheels from being locked by an increase in regenerative braking force, and second prevention control for preventing the wheels from being locked by an increase in friction braking force; a failure determination unit that detects a failure of the anti-lock control unit; and a threshold value changing unit that changes output threshold values of the regenerative braking force and the friction braking force. Wherein, when a failure of the first prevention control is detected in the failure determination unit, the control device changes the output threshold value of the regenerative braking force to a failure threshold value that is smaller than the output threshold value of the current regenerative braking force, and adds the friction braking force to a braking force that is insufficient with respect to the demand braking force.

Description

Technical Field

[0001] The present invention relates to a vehicle control device, and in particular to a vehicle control device for controlling the braking force of a vehicle. Background Art

[0002] In recent years, efforts have been actively made to provide access to sustainable transportation systems that also take into account vulnerable people such as the elderly and children among traffic participants. In order to achieve this goal, research and development efforts are being made to further improve the safety and convenience of traffic through developments related to vehicle behavior stability technology.

[0003] Patent document 1 discloses an electric vehicle braking device, which does not perform regenerative braking of the rear wheel (drive wheel) when the regenerative braking system does not work properly, and performs friction braking with a higher braking force response than regenerative braking by hydraulically braking the front and rear wheels. Patent document 1 also discloses a wheel anti-lock control, which reduces the brake hydraulic pressure by controlling the anti-lock brake system (ABS) control valve when it is detected from the output signal of the wheel speed sensor that the wheel is about to enter a locked state.

[0004] However, the prior art does not mention the case where the anti-lock control fails when the regenerative braking system is normal, and regenerative braking is not performed even in the area where regenerative braking is possible (the area where the wheels are not locked). Therefore, regenerative loss may occur, and there is room for improvement.

[0005] [Prior art literature]

[0006] [Patent Document]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 5-161210 Summary of the invention

[0008] In the vehicle behavior stability technology, how to properly adjust the regenerative braking force and the friction braking force is a subject for designers in this field.

[0009] In order to solve the above-mentioned problems, the present invention aims to achieve the goal of being able to use regenerative braking force and maintain the required braking force even when a functional failure occurs that prevents locking due to regenerative braking force. Furthermore, it contributes to the development of a sustainable transportation system.

[0010] In order to achieve the above object, the present invention is a vehicle control device, which includes a regenerative braking device for applying regenerative braking force to wheels in the vehicle, a friction braking device for applying friction braking force to wheels, and a control device for controlling regenerative braking force and friction braking force based on the braking force to be applied to the vehicle, i.e., the required braking force. The control device has an anti-lock control unit, a fault determination unit, and a threshold change unit. The anti-lock control unit is used to perform a first preventive control for preventing wheels from being locked due to an increase in regenerative braking force, and a second preventive control for preventing wheels from being locked due to an increase in friction braking force. The fault determination unit is used to detect a fault in the anti-lock control unit. The threshold change unit is used to change the output thresholds of the regenerative braking force and the friction braking force. Among them, when the control device detects a fault in the first preventive control in the fault determination unit, it changes the output threshold of the regenerative braking force to a fault threshold that is less than the current output threshold of the regenerative braking force, and adds the friction braking force to the braking force that is insufficient relative to the required braking force.

[0011] According to the above structure, it is possible to determine whether the first preventive control for preventing wheel lock caused by regenerative braking is faulty, and when it is determined that the first preventive control is faulty, it is determined that the wheel lock caused by regenerative braking cannot be prevented, and the output threshold of the regenerative braking when the first preventive control is normal is changed to a fault threshold value smaller than the output threshold value when the first preventive control is normal, and control to increase the friction braking force is implemented. Thus, by reducing the braking amount required for regenerative braking and adding friction braking to the required braking force, a system for preventing wheel lock due to friction braking can be used, thereby improving applicability.

[0012] In one embodiment of the present invention, the fault threshold is a set value pre-stored in the fault judgment unit according to the vehicle condition, and the upper limit of the set value of the fault threshold is the braking force that does not lock the wheels even if regenerative braking force is applied to the vehicle when the road friction coefficient is low.

[0013] According to the structure, by setting the default fault threshold in the fault judgment unit to a setting value that does not lock on low-friction roads (such as extremely slippery roads such as icy roads) based on the vehicle conditions (vehicle weight, tire size, brake size, regenerative braking force that can be generated, etc.), there is no need for sensors for detecting the road friction coefficient and computing equipment for calculating the threshold, and braking control can be achieved at low cost and low computing cost.

[0014] In one embodiment of the present invention, the threshold changing unit gradually reduces the normal threshold to the fault threshold.

[0015] According to the structure, when the engine drag control (EDC) failure is determined and the output threshold of the current regenerative braking force is changed to a smaller output threshold, the vehicle may experience vibration if the change is made suddenly. Therefore, by gradually making the output threshold smaller, the occurrence of shock can be prevented, thereby improving applicability.

[0016] In one embodiment of the present invention, when the threshold changing unit receives an input of additional required braking force during the period of gradually decreasing from the normal threshold to the failure threshold, it stops gradually decreasing the output threshold and directly changes it to the failure threshold.

[0017] According to the structure, if there is additional required braking force input during the gradual reduction of the output threshold, by terminating the gradual reduction of the output threshold and immediately changing it to the fault threshold, it is possible to reliably switch to the control of the system (ABS) that prevents the wheels from locking due to friction braking.

[0018] Based on the above, the vehicle control device of the present invention reduces the output threshold of the regenerative braking when it is determined that the wheel lock caused by the regenerative braking cannot be prevented, and at the same time implements the control of increasing the friction braking force. Thus, by reducing the braking amount required for the regenerative braking and adding the friction braking to the required braking force, a system for preventing the wheel from locking due to the friction braking can be used, thereby improving applicability.

[0019] In order to make the above features and advantages of the present invention more obvious and easy to understand, the following embodiments are specifically cited and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A schematic block diagram showing a vehicle control device according to an embodiment of the present invention.

[0021] Figure 2 A schematic diagram showing engine drag control fault detection according to an embodiment of the present invention.

[0022] Figure 3 A flow chart showing a vehicle control method according to an embodiment of the present invention.

[0023] Figure 4A and Figure 4B This is a comparative example showing vehicle braking force control according to an embodiment of the present invention.

[0024] Figure 5 FIG. 1 is an example of vehicle braking force control according to an embodiment of the present invention.

[0025] Figure 6 FIG. 1 is an example of vehicle braking force control according to an embodiment of the present invention.

[0026] Figure 7FIG. 1 is an example of vehicle braking force control according to an embodiment of the present invention.

[0027] Figure 8 FIG. 1 is an example of vehicle braking force control according to an embodiment of the present invention.

[0028] Description of Reference Numerals

[0029] 100: Vehicle control device

[0030] 110: Regenerative braking device

[0031] 120: Friction brake device

[0032] 130: Control device

[0033] 132: Anti-lock control unit

[0034] 134: Fault determination unit

[0035] 136: Threshold change unit

[0036] 210: Wheel speed sensor

[0037] 220: Yaw / Gravity sensor

[0038] 230: VSA-ECU

[0039] 240:MG-ECU

[0040] t1~t10: time point

[0041] TH1~TH5: Output threshold of regenerative braking force

[0042] R: Region

[0043] ΔTH: Threshold difference

[0044] S302~S312: Steps DETAILED DESCRIPTION

[0045] Reference will now be made in detail to exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Whenever possible, the same reference numerals are used in the drawings and the description to refer to the same or like parts.

[0046] The vehicle control device of the embodiment of the present invention determines whether the preventive control for preventing "wheel lock due to increased regenerative braking" has failed. If it is determined that the preventive control has failed, the wheel lock caused by regenerative braking cannot be prevented. At this time, the output threshold (first threshold) of the regenerative braking under normal conditions is changed to a fault threshold (second threshold) that is smaller than the output threshold under normal conditions to reduce the braking amount required for regenerative braking, and friction braking is added to the required braking force. Therefore, an anti-lock brake system (ABS) that prevents the wheels from locking due to friction braking can be used, thereby improving applicability.

[0047] Figure 1 A schematic block diagram showing a vehicle control device according to an embodiment of the present invention. Figure 1 The vehicle control device 100 of this embodiment is, for example, configured in the vehicle itself to control the braking force of the vehicle itself. In this embodiment, the vehicle itself includes, for example, a car using an internal combustion engine such as a diesel engine or a gasoline engine as a power source, an electric car using an electric motor as a power source, or a hybrid car having both an internal combustion engine and an electric motor.

[0048] The vehicle control device 100 includes a regenerative braking device 110 in the vehicle for applying regenerative braking force to the wheels, a friction braking device 120 for applying friction braking force to the wheels, and a control device 130 for controlling the regenerative braking force and the friction braking force based on the braking force to be applied to the vehicle, i.e., the required braking force.

[0049] The regenerative braking device 110 is used to recover the vehicle kinetic energy dissipated as heat by the friction braking system. It is connected to a motor of at least one of the front wheels and the rear wheels of the own vehicle to control the motor to generate regenerative braking force on the front wheels or the rear wheels according to the target braking force. The target braking force is the braking force determined by the driving or vehicle behavior stability control system of the own vehicle according to the current driving conditions. The kinetic energy recovery is achieved by using the above-mentioned motor as a generator during braking to convert the vehicle kinetic energy into electricity and store it in a battery or other energy storage device. In some embodiments, the regenerative braking device 110 can generate regenerative braking force by adjusting the speed of the motor, but is not limited to this.

[0050] The friction brake device 120, for example, generates friction force by friction between a brake disc made of cast iron or composite ceramic and a brake pad to brake the vehicle. In some embodiments, the friction brake device 330 can also brake the vehicle by other means such as hydraulic, air braking or resistance braking. This embodiment does not limit the braking method.

[0051] The control device 130 is implemented, for example, by executing a program through a processor, or by hardware such as a large scale integrated circuit (LSI) or an application specific integrated circuit (ASIC), or by a combination of software and hardware, and this embodiment does not limit the implementation method thereof. In some embodiments, the control device 130 is, for example, a motor generator (MG)-electronic control unit (ECU), and can control the regenerative braking force and the friction braking force based on the braking force to be applied to the vehicle, i.e., the required braking force.

[0052] The control device 130 includes an anti-lock control unit 132 , a failure determination unit 134 , and a threshold value changing unit 136 .

[0053] The anti-lock control unit 132 is used to execute a first preventive control for preventing the wheels from locking due to an increase in regenerative braking force, and a second preventive control for preventing the wheels from locking due to an increase in friction braking force. The first preventive control described above corresponds to a conventional engine drag control (EDC) system, but unlike the conventional EDC system, the first preventive control of this embodiment controls the driving force by reducing rather than increasing the driving force when wheel lock is detected, thereby achieving an anti-lock control different from the conventional EDC system. The second preventive control described above corresponds to an anti-lock braking system (ABS).

[0054] The fault determination unit 134 is used to detect faults of the anti-lock control unit 132, including faults of the first preventive control and faults of the second preventive control. The fault determination is implemented by, for example, a vehicle stability control system (VSA)-electronic control unit (ECU), which, for example, sends fault information to the MG-ECU via a controller area network (CAN) when a fault is determined.

[0055] The threshold value changing unit 136 is used to change the output threshold values ​​of the regenerative braking force and the friction braking force.

[0056] Figure 2 A schematic diagram showing an engine drag control (EDC) fault detection according to an embodiment of the present invention. Figure 2In the present embodiment, the EDC fault detection is performed by the wheel speed sensor 210 detecting the wheel speed and transmitting the wheel speed pulse to the VSA-ECU 230. In addition, the yaw / gravity (G) sensor 220 detects the yaw and acceleration of the vehicle and transmits the detection result to the VSA-ECU 230 via the controller area network (CAN).

[0057] The VSA-ECU 230 can be used as the fault determination unit 134 of the aforementioned embodiment, and can perform fault diagnosis of the wheel speed sensor 210, fault diagnosis of the yaw / gravity sensor 220, and fault diagnosis of the controller area network according to the wheel speed provided by the wheel speed sensor 210 and the yaw and acceleration provided by the yaw / gravity sensor 220, and determine the fault of the engine drag control (EDC) system according to the diagnosis results. Among them, when the wheel speed sensor 210 fails, friction braking cannot be generated, and regenerative braking will also be limited.

[0058] When a fault in the EDC system is determined, the VSA-ECU 230 transmits EDC fault information to the MG-ECU 240 via the controller area network.

[0059] The MG-ECU 240 may serve as the control device 130 of the aforementioned embodiment, and determines whether to execute FSA (Fail Safe Action) based on the EDC failure information and the CAN failure information provided by the VSA-ECU 230 .

[0060] In detail, when the control device 130 detects a fault in the first preventive control in the fault judgment unit 134, it will change the output threshold of the regenerative braking force to a fault threshold that is smaller than the current output threshold of the regenerative braking force through the threshold change unit 136, and add the friction braking force to the braking force that is insufficient relative to the required braking force to maintain the required braking force.

[0061] Thus, by reducing the amount of braking required for regenerative braking and adding friction braking to the required braking force, a system that prevents wheels from locking due to friction braking (ie, ABS) can be used, thereby improving serviceability.

[0062] Figure 3 A flow chart showing a vehicle control method according to an embodiment of the present invention is shown. Figure 1 and Figure 3 The vehicle control method of this embodiment is applicable to Figure 1 The vehicle control device 100 of the embodiment is described below with reference to the various components in the vehicle control device 100 to describe the detailed steps of the vehicle control method of this embodiment.

[0063] In step S302, the control device 130 controls the regenerative braking force and the friction braking force based on the braking force to be applied to the vehicle, i.e., the required braking force. The required braking force is determined, for example, in response to the driver's stepping operation on the brake pedal, or in response to the automatic driving system such as the Advanced Driver Assistance Systems (ADAS) and the Adaptive Cruise Control (ACC) system when performing automatic driving; by the vehicle stability assistance (VSA) system such as the Anti-lock Braking System (ABS) and the Traction Control System (TCS) when performing vehicle assistance; or by the Autonomous Emergency Braking (AEB) system when performing emergency braking, in response to the road conditions ahead or the surrounding environment, and there is no limitation here.

[0064] In step S304, the first preventive control for preventing the wheels from locking due to the increase of the regenerative braking force and the second preventive control for preventing the wheels from locking due to the increase of the friction braking force are executed by the anti-lock control unit 132. The first preventive control corresponds to the engine drag control (EDC) system, and the second preventive control corresponds to the anti-lock brake system (ABS).

[0065] In step S306, the fault determination unit 134 detects the fault of the anti-lock control unit 134. In some embodiments, the fault determination unit 134 performs, for example, wheel speed sensor fault diagnosis, yaw / gravity sensor fault diagnosis, and CAN fault diagnosis based on the wheel speed provided by the wheel speed sensor and the yaw and acceleration provided by the yaw / gravity sensor, and determines the fault of the EDC system based on the diagnosis results. In some embodiments, the fault determination unit 134 also includes detecting abnormal communication with each sensor, and determining the fault of the EDC system. This embodiment does not limit the method of detecting the fault of the anti-lock control unit 134.

[0066] In step S308 , the control device 130 determines whether a failure of the first preventive control is detected in the failure determination unit 134 .

[0067] If it is determined that a fault of the first preventive control is detected in the fault determination unit 134, the output threshold of the regenerative braking force is changed to a fault threshold value that is smaller than the current output threshold of the regenerative braking force by the threshold change unit 136, and the braking force that is insufficient relative to the required braking force is added with the friction braking force. The fault threshold value is a set value pre-stored in the fault determination unit 134 according to the vehicle condition, and the upper limit of the set value of the fault threshold value is a braking force that does not lock the wheels even if the regenerative braking force is applied to the vehicle when the road friction coefficient (μ) is low.

[0068] Specifically, by setting the fault threshold to a setting value that does not lock on a low friction coefficient road (such as an extremely slippery road such as an icy road) in the fault determination unit 134 according to the vehicle condition (vehicle weight, tire size, brake size, regenerative braking force that can be generated, etc.), a sensor for detecting the road friction coefficient and a computing device for calculating the threshold are not required, and braking control can be achieved at low cost and low computing cost. Regardless of whether it is a dry road or a low friction coefficient road, when the first preventive control fault is detected, the fault threshold is uniformly applied to prevent wheel lock caused by regenerative braking.

[0069] On the contrary, if it is determined in the failure determination unit 134 that no failure of the first preventive control is detected, the control device 130 will maintain the current output threshold value of the regenerative braking force.

[0070] Therefore, by reducing the braking amount required for regenerative braking and adding friction braking to the required braking force when determining the first preventive control failure, the method of this embodiment can use a system to prevent the wheels from locking due to friction braking, thereby improving applicability.

[0071] For example, Figure 4A and Figure 4B FIG. 1 is a comparative example of vehicle braking force control according to an embodiment of the present invention. Figure 4A The curve showing the change of braking force over time when the first preventive control (i.e., EDC system) in the above-mentioned embodiment is normal. When the vehicle is traveling on a low-friction coefficient road surface, the vehicle control device controls the regenerative braking device to apply a regenerative braking force of 0.04G to the wheels. Among them, 0.04G is, for example, a braking force that does not lock the wheels even if a regenerative braking force is applied to the vehicle when the road friction coefficient is low, that is, a braking force that prevents the wheels from locking on a low-friction coefficient road surface.

[0072] When the B gear operation is received at time point t1, the regenerative braking device controls the regenerative braking force applied to the wheels by the regenerative braking device and the friction braking force applied to the wheels by the friction braking device based on the braking force to be applied to the vehicle, i.e., the required braking force (e.g., 0.1G). Among them, the vehicle control device first controls the regenerative braking device to gradually increase the regenerative braking force applied to the wheels, and when the regenerative braking force reaches the output threshold TH1, controls the friction braking device to apply the friction braking force to the wheels until the sum of the regenerative braking force and the friction braking force reaches the required braking force. The "B gear" is, for example, a "regenerative braking" mode unique to hybrid vehicles, which can generate regenerative braking force on the wheels through the motor connected to the wheels.

[0073] Figure 4B The curve showing the change of braking force over time when the first preventive control failure occurs in the above-mentioned embodiment. When the vehicle is driving on a low friction coefficient road surface, the vehicle control device controls the regenerative braking device to apply a regenerative braking force of 0.04G to the wheels. At this time, the vehicle control device sets the output threshold of the regenerative braking force to TH1.

[0074] Based on the detection of the fault of the first preventive control in the fault determination unit, the vehicle control device changes the output threshold of the regenerative braking force to a fault threshold (e.g., 0.04G) less than the current output threshold TH1, that is, the output threshold TH1 of the regenerative braking force is reduced by the threshold difference ΔTH. In addition, the vehicle control device also controls the friction braking device to add the braking force that is insufficient relative to the required braking force to the friction braking force until the sum of the regenerative braking force and the friction braking force reaches the required braking force.

[0075] It should be noted that when an EDC fault is determined and the current output threshold of the regenerative braking force is changed to a smaller output threshold, if the change is made suddenly, the vehicle may experience vibration. Therefore, in some embodiments, when the threshold value changing unit 136 changes the output threshold of the regenerative braking force, it gradually reduces the normal threshold to the fault threshold. Thus, by gradually reducing the output threshold, the occurrence of shock can be prevented, thereby improving applicability.

[0076] For example, Figure 5 is an example of vehicle braking force control according to an embodiment of the present invention. Figure 5 The curve showing the change of braking force over time when the first preventive control (i.e., EDC system) fails in the above-mentioned embodiment. When the vehicle is traveling on a low friction coefficient road surface, the vehicle control device controls the regenerative braking device to apply a regenerative braking force of 0.04G to the wheels. At this time, the vehicle control device sets the output threshold TH2 of the regenerative braking force to 0.1G.

[0077] When the first preventive control (i.e., EDC system) fault is detected in the EDC fault information at time point t3, the vehicle control device gradually reduces the output threshold TH2 of the regenerative braking force from the current output threshold (i.e., 0.1G) to the fault threshold (e.g., 0.04G). As a condition for gradually reducing, the vehicle control device reduces the output threshold at a rate of change of 0.5G / s, for example, to avoid a transition shock, but the present embodiment is not limited thereto.

[0078] When the B gear operation is received at time point t4, the regenerative braking device is controlled to gradually increase the regenerative braking force applied to the wheels based on the braking force to be applied to the vehicle, namely the required braking force (for example, 0.1G), and when the regenerative braking force reaches the fault threshold (i.e., 0.04G), the friction braking device is controlled to apply friction braking force to the wheels until the sum of the regenerative braking force and the friction braking force reaches the required braking force.

[0079] In some embodiments, when the threshold value changing unit 136 receives an input of additional required braking force during the period of gradually decreasing from the normal threshold value to the fault threshold value, it stops gradually decreasing the output threshold value and directly changes it to the fault threshold value. Thus, when there is an additional required braking force input during the process of gradually decreasing the output threshold value, by terminating the gradual decrease of the output threshold value and immediately changing it to the fault threshold value, it is possible to reliably switch to the control of the system (ABS) that prevents wheels from locking due to friction braking.

[0080] For example, Figure 6 is an example of vehicle braking force control according to an embodiment of the present invention. Figure 6 The curve showing the change of braking force over time when the first preventive control (i.e., EDC system) fails in the above-mentioned embodiment. When the vehicle is traveling on a low friction coefficient road surface, the vehicle control device controls the regenerative braking device to apply a regenerative braking force of 0.04G to the wheels. At this time, the vehicle control device sets the output threshold TH3 of the regenerative braking force to 0.1G.

[0081] When a first preventive control (ie, EDC system) fault is detected in the EDC fault information at time point t5, the vehicle control device gradually reduces the output threshold TH3 of the regenerative braking force from the current output threshold (ie, 0.1G) to the fault threshold (eg, 0.04G).

[0082] However, during the process of gradual decrease of the output threshold TH3, if an operation of the B gear is received at time point t6 and additional braking force is required, the vehicle control device will terminate the gradual reduction of the output threshold and immediately change the output threshold TH3 of the regenerative braking force to the fault threshold (such as directly changing it to 0.04G as shown in area R).

[0083] Thus, by immediately switching the regenerative braking force output threshold TH3 to a failure threshold at which the wheels will not lock even when regenerative braking force is applied to the vehicle on a low friction coefficient road, control can be reliably switched to the system (ABS) that prevents wheels from locking due to friction braking.

[0084] Figure 7 is an example of vehicle braking force control according to an embodiment of the present invention. Figure 7 The curve showing the change of braking force over time when the first preventive control (i.e., EDC system) fails in the above-mentioned embodiment. When the vehicle is traveling on a low friction coefficient road surface, the vehicle control device controls the regenerative braking device to apply a regenerative braking force of 0.04G to the wheels. At this time, the vehicle control device sets the output threshold TH4 of the regenerative braking force to 0.1G.

[0085] When a first preventive control (ie, EDC system) fault is detected in the EDC fault information at time point t7, the vehicle control device gradually reduces the output threshold TH4 of the regenerative braking force from the current output threshold (ie, 0.1G) to the fault threshold (eg, 0.04G).

[0086] However, during the process of gradually decreasing the output threshold TH4, if the B gear operation is received at time point t8, the vehicle control device continues to gradually decrease the output threshold TH4 of the regenerative braking force until the failure threshold (ie, 0.04G) is reached.

[0087] As a result, although a lot of regenerative braking force will be generated instantly, this regenerative braking force will decrease quickly, so it will not cause the wheels to lock and cause skidding.

[0088] Figure 8 is an example of vehicle braking force control according to an embodiment of the present invention. Figure 8 The curve showing the change of braking force over time when the first preventive control (i.e., EDC system) fails in the above-mentioned embodiment. In this embodiment, it is assumed that the regenerative braking device of the vehicle is a model that sets the basic regenerative braking force to a larger value (e.g., 0.06G). Therefore, when the vehicle is traveling on a low friction coefficient road surface, the regenerative braking device is controlled by the vehicle control device to apply a regenerative braking force of 0.06G to the wheels. At this time, the vehicle control device sets the output threshold TH5 of the regenerative braking force to 0.1G.

[0089] When a first preventive control (i.e., EDC system) fault is detected in the EDC fault information at time point t7, the vehicle control device will gradually reduce the output threshold TH5 of the regenerative braking force from the current output threshold (i.e., 0.1G) to a fault threshold (e.g., 0.04G) that is smaller than the originally set regenerative braking force of 0.06G, i.e., reducing the amount of regenerative braking when the EDC system fails.

[0090] Thus, even if the setting of the basic regenerative braking force of the regenerative braking device is different for each vehicle, it is still possible to reliably switch to the control of the system for preventing the wheels from locking due to friction braking.

[0091] In summary, the vehicle control device of the present invention reduces the output threshold of regenerative braking when it is determined that the wheel lock caused by regenerative braking cannot be prevented, and at the same time implements control to increase the friction braking force. Thus, by reducing the braking amount required for regenerative braking and adding friction braking to the required braking force, a system that prevents the wheel from locking due to friction braking can be used, thereby improving applicability. In addition, by gradually reducing the output threshold, the occurrence of impact can be prevented, and when there is an additional required braking force input, by terminating the gradual reduction of the output threshold and immediately changing it to the fault threshold, it is possible to reliably switch to the control of the system (ABS) that prevents the wheel from locking due to friction braking, thereby improving applicability.

[0092] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A vehicle control device, characterized in that: include: In the vehicle: A regenerative braking device applies regenerative braking force to the wheels; A friction brake device applies a friction braking force to the wheel; as well as a control device that controls the regenerative braking force and the friction braking force based on a braking force to be applied to the vehicle, i.e., a required braking force, wherein The control device has: an anti-lock control unit that performs a first preventive control for preventing the wheel from locking due to an increase in the regenerative braking force and a second preventive control for preventing the wheel from locking due to an increase in the friction braking force; a fault determination unit, for detecting a fault of the anti-lock control unit; as well as a threshold value changing unit, which changes the output threshold values ​​of the regenerative braking force and the friction braking force, wherein When the control device detects a failure of the first preventive control in the failure determination unit, the control device changes the output threshold of the regenerative braking force to a failure threshold that is smaller than the current output threshold of the regenerative braking force, and adds friction braking force to the braking force that is insufficient relative to the required braking force.

2. The vehicle control device according to claim 1, characterized in that: The fault threshold is a set value pre-stored in the fault determination unit according to the condition of the vehicle, and The upper limit of the set value of the failure threshold value is a braking force that does not lock the wheels even if the regenerative braking force is applied to the vehicle when the road surface friction coefficient is low.

3. The vehicle control device according to claim 1, characterized in that: The threshold value changing unit gradually reduces the normal threshold value to the failure threshold value.

4. The vehicle control device according to claim 3, characterized in that: When receiving an input of an additional required braking force during the period of gradually decreasing the output threshold from the normal threshold to the failure threshold, the threshold changing unit stops gradually decreasing the output threshold and directly changes the output threshold to the failure threshold.

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