Apparatus for controlling breaking for vehicle and control method thereof

Abstract

A braking control device for a vehicle may include: a wheel speed sensor for measuring the wheel speed of the vehicle; a wheel braking device for controlling the braking pressure of the wheel; and a processor that determines a wheel slip ratio, the speed and deceleration of the vehicle based on the wheel speed, determines a wheel speed restoration reference value based on the wheel slip ratio, speed and deceleration, and if the wheel speed restoration time during which the wheel speed recovers from an abnormal value exceeds the wheel speed restoration reference value, determines a target wheel slip ratio based on the determined wheel slip ratio, determines a target wheel speed based on the target wheel slip ratio, determines whether to reduce, maintain, or increase the pressure of the wheel based on a comparison between the wheel speed and the target wheel speed, and transmits a signal for reducing, maintaining, or increasing the pressure of the wheel to the wheel braking device.

Description

Technology Field

[0001] The present invention relates to a vehicle braking control device on an irregular road surface and a control method thereof. Background Technology

[0002] Vehicle speed is determined by the friction between the road surface and the tires. Only a portion of the driving torque is transmitted to the road surface to accelerate the vehicle, and the remaining excess torque causes a rapid increase in the rotational speed of the drive shaft, which can lead to excessive wheel slip.

[0003] To prevent excessive wheel slip, systems such as ABS (Anti-Lock Brake System) and TCS (Traction Control System) are being proposed. Among these, ABS detects excessive wheel slip and minimizes braking distance by repeatedly applying and releasing the brakes through hydraulic pressure.

[0004] Generally, ABS is designed to secure braking power by increasing the target wheel slip ratio to account for the phenomenon where the rotational speed of each wheel varies on irregular road surfaces. A conventional ABS regarding this is disclosed in Japanese Registered Patent Publication No. 4342175.

[0005] However, conventional ABS had limitations in accurately detecting various types of irregular road surfaces. If ABS fails to accurately detect irregular road surfaces, accidents may occur due to insufficient braking power. For example, if wheel bouncing occurs on irregular road surfaces such as rough or extremely difficult terrain, the vehicle speed may be overestimated, resulting in a failure to secure wheel braking pressure and potentially causing an accident. The problem to be solved

[0006] An embodiment of the present invention aims to provide a vehicle braking control device and a control method thereof that can secure braking force even when an irregular road surface is not detected. means of solving the problem

[0007] According to an embodiment of the present invention, a vehicle braking control device may be provided comprising: a wheel speed sensor for measuring the wheel speed of a vehicle; a wheel braking device for controlling the braking pressure of a wheel; and a processor for determining a wheel slip ratio, the speed and deceleration of the vehicle based on the wheel speed, determining a wheel speed restoration reference value based on the wheel slip ratio, the speed and deceleration, and if the wheel speed restoration time during which the wheel speed recovers from an abnormal value exceeds the wheel speed restoration reference value, determining a target wheel slip ratio based on the determined wheel slip ratio, determining a target wheel speed based on the target wheel slip ratio, determining whether to reduce, maintain, or increase the pressure of the wheel based on a comparison between the wheel speed and the target wheel speed, and transmitting a signal for reducing, maintaining, or increasing the pressure of the wheel to the wheel braking device.

[0008] When the processor transmits a signal for depressurization or maintenance of the wheel to the wheel braking device, it can initialize the wheel speed restoration time and the wheel speed restoration reference value.

[0009] The above processor can determine the wheel speed restoration reference value based on the maximum wheel slip rate, where the wheel slip rate is the maximum value.

[0010] The above processor can count the wheel speed recovery time from the maximum wheel slip rate.

[0011] The above processor can determine the road surface based on the deceleration of the vehicle and determine the target wheel slip rate based on the road surface.

[0012] The above processor determines first and second target wheel slip rates based on the road surface, and

[0013] Based on the first and second target wheel slip ratios above, the first and second target wheel speeds are determined, and if the wheel speed is greater than the first target wheel speed, a pressure increase signal is generated, if the wheel speed is less than the first target wheel speed and greater than the second target wheel speed, a maintenance signal is generated, and if the wheel speed is less than the second target wheel speed, a pressure decrease signal is generated.

[0014] According to another embodiment of the present invention, a vehicle braking control method may be provided, comprising determining a wheel slip ratio, the speed and deceleration of the vehicle based on the wheel speed, determining a wheel speed restoration reference value based on the wheel slip ratio, speed and deceleration, and if the wheel speed restoration time during which the wheel speed recovers from an abnormal value exceeds the wheel speed restoration reference value, determining a target wheel slip ratio based on the determined wheel slip ratio, determining a target wheel speed based on the target wheel slip ratio, determining whether to reduce, maintain, or increase the pressure of the wheel based on a comparison between the wheel speed and the target wheel speed, and transmitting a signal for reducing, maintaining, or increasing the pressure of the wheel to the wheel braking device. Effects of the invention

[0015] A vehicle braking control device and a control method according to an embodiment of the present invention determine a target wheel slip ratio based on the wheel speed recovery time, thereby solving the problem of wheel slip being overestimated due to overestimation of vehicle speed on an undetermined special irregular road surface. Accordingly, the wheel braking force of the vehicle can be secured, thereby increasing vehicle driving stability on an irregular road surface.

[0016] The effects of the present invention are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art from the description in the claims. Brief explanation of the drawing

[0017] FIG. 1 illustrates the control configuration of a vehicle braking control device according to one embodiment. FIG. 2 illustrates a control case applying a vehicle braking control device according to one embodiment. FIG. 3 illustrates the braking control operation of a vehicle braking control device according to one embodiment. FIG. 4 illustrates the wheel pressure control operation of a vehicle braking control device according to one embodiment. FIG. 5 relates to a wheel pressure control operation that may occur after target wheel slip rate compensation is performed as the wheel speed recovery time in FIG. 4 exceeds the wheel speed recovery reference time. Specific details for implementing the invention

[0018] Throughout the specification, the same reference numerals refer to the same components. This specification does not describe all elements of the embodiments, and general content in the art to which the disclosed invention pertains or content that overlaps between embodiments is omitted.

[0019] Furthermore, when it is stated that a part "includes" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0020] Terms such as "first," "second," etc., are used to distinguish one component from another, and the components are not limited by the aforementioned terms.

[0021] Singular expressions include plural expressions unless there is an obvious exception in the context.

[0022] In each step, identification codes are used for convenience of explanation and do not describe the order of the steps; the steps may be performed differently from the specified order unless a specific order is clearly indicated in the context.

[0023] The operating principle and embodiments of the disclosed invention will be described below with reference to the attached drawings.

[0024] FIG. 1 illustrates the control configuration of a vehicle braking control device according to one embodiment.

[0025] Referring to FIG. 1, the vehicle braking control device (100) may include a processor (110), a wheel speed sensor (120), and a wheel braking device (130). The components shown in FIG. 1 are not essential components of the vehicle braking control device (100), and at least some of them may be omitted.

[0026] The wheel speed sensor (120) can measure the wheel speeds of the front and rear wheels of the vehicle and provide an electrical signal corresponding to the measured wheel speed voltage to the processor (110).

[0027] The wheel speed sensor (120) can provide the wheel speed of the vehicle, measured in real time at regular intervals, to the processor (110). The measured wheel speed can be measured as a total of four wheel speeds, including the front wheels and the rear wheels.

[0028] The wheel braking device (130) receives a wheel pressure control signal from the processor (110) and can control the wheel braking pressure to apply a braking pressure corresponding to the received wheel pressure control signal to the wheel.

[0029] When the wheel braking device (130) receives a signal from the processor (110) to reduce, maintain, or increase the braking pressure based on the wheel braking pressure, it can reduce, maintain, or increase the braking pressure, but is not limited to this and can be freely applied according to the technical situation of the developer.

[0030] The processor (110) can communicate with the wheel speed sensor (120) and the wheel braking device (130). The processor (110) can receive the wheel speed from the wheel speed sensor (120) and provide a signal to the wheel braking device (130) to reduce, maintain, or increase the pressure of the wheel.

[0031] The processor (110) can determine the wheel slip rate, vehicle speed, and deceleration based on the received wheel speed, and determine the wheel speed restoration reference value based on the determined wheel slip rate, vehicle speed, and deceleration voltages.

[0032] When the actual wheel speed restoration time exceeds the determined wheel speed restoration reference value, the processor (110) determines the target wheel slip rate based on the road surface condition and the wheel slip rate, converts the determined target wheel slip rate into the target wheel speed, and then generates a signal to reduce, maintain, or increase the pressure of the wheel based on a comparison between the wheel speed and the target wheel speed.

[0033] FIG. 2 illustrates a control case applying a vehicle braking control device according to one embodiment.

[0034] Referring to FIG. 2, the processor (110) can count the wheel speed recovery time from when the determined wheel slip rate is at the maximum wheel slip rate (T1) which is outside the abnormal value and indicates the maximum value, until when it is recovered to the normal value (T2), and can initialize when the wheel slip rate is recovered to the normal value (T2).

[0035] Additionally, when the processor (110) transmits a signal for depressurizing or maintaining the wheel to the wheel braking device (130), it can initialize the wheel speed restoration time and the wheel speed restoration reference value.

[0036] The processor (110) can determine that target wheel slip compensation is necessary if the counted wheel speed recovery time is greater than the wheel speed recovery reference value, and conversely, determine that target wheel slip compensation is unnecessary if the counted wheel speed recovery time is less than the wheel speed recovery reference value.

[0037] The processor (110) can determine the road surface based on the vehicle's deceleration and then determine the target wheel slip rate based on the road surface. Specifically, the processor (110) can determine the first and second target wheel slip rates (not shown) based on the determined road surface.

[0038] If the processor (110) determines that target wheel slip compensation is required, it can additionally compensate for the target wheel slip based on the determined wheel slip rate. That is, if the counted wheel speed recovery time is greater than the wheel speed recovery reference value, the processor (110) can determine the target wheel slip by reflecting the wheel slip rate together with the road surface, and the wheel slip rate at this time may be the wheel slip rate at the time when it was first determined that target wheel slip compensation is required.

[0039] The processor (110) can determine the target wheel speed based on the target wheel slip rate. Specifically, the processor (110) can determine the first and second target wheel speeds (31, 32) based on the first and second target wheel slip rates (not shown).

[0040] The processor (110) determines whether to reduce, maintain, or increase the pressure of the wheel based on a comparison between the wheel speed and the target wheel speed, and can transmit a signal to the wheel braking device (130) to reduce, maintain, or increase the pressure of the wheel.

[0041] The processor (110) can generate a pressure boosting signal if the first or second wheel speed (11, 12) is greater than the first target wheel speed (31), generate a maintenance signal if the first or second wheel speed (11, 12) is less than the first target wheel speed (31) and greater than the second target wheel speed (32), and generate a pressure reduction signal if the first or second wheel speed (11, 12) is less than the second target wheel speed (32).

[0042] In conventional ABS, for example, if the second wheel speed (12) is erratic due to an irregular road surface and the speed increases rapidly, the vehicle speed (20) is overestimated, and consequently, the wheel slip rate increases, which can cause the first and second target wheel speeds (31a, 32a) to increase. A conventional processor (not shown) may output multiple signals for maintaining or reducing pressure as wheel pressure control signals when the wheel slip rate increases. If this phenomenon persists, braking force cannot be properly applied to the second wheel (not shown), and the wheel braking pressure may instead be reduced.

[0043] However, the processor (110) can compensate for the target wheel slip rate when the wheel speed recovery time exceeds the wheel speed recovery reference value, and accordingly, the first and second target wheel speeds (31b, 32b) can be readjusted. The processor (110) determines whether to reduce, maintain, or increase the pressure of the wheel based on the readjusted first and second target wheel speeds (31b, 32b), and outputs a pressure increase signal as a wheel pressure control signal, thereby increasing the braking pressure of the second wheel (not shown) to ensure braking stability.

[0044] FIG. 3 illustrates the braking control operation of a vehicle braking control device according to one embodiment.

[0045] Referring to FIG. 3, the processor (110) can receive the wheel speed from the wheel speed sensor (120) and determine the wheel slip rate, the speed of the vehicle, and the deceleration (S1000).

[0046] The processor (110) can determine a target wheel slip rate based on the deceleration of the vehicle determined or a road surface image provided by a driving assistance device (not shown), and perform ABS control corresponding thereto (S2000).

[0047] The processor (110) can control the wheel braking device (130) by checking whether the wheel speed recovery time exceeds the wheel speed recovery reference time and generating a corresponding electrical signal to increase, maintain, or decrease the braking pressure of the wheel (S3000)

[0048] FIG. 4 illustrates the wheel pressure control operation of a vehicle braking control device according to one embodiment.

[0049] Referring to FIG. 4, the processor (110) can check whether a signal for reducing or maintaining the wheel has been transmitted to the wheel braking device (130) (S3100).

[0050] When the processor (110) transmits a pressure reduction or maintenance signal of the wheel, it initializes the wheel speed restoration time and the wheel speed restoration reference value, and conversely, when it transmits a pressure increase signal of the wheel, it can determine the wheel speed restoration reference value based on the wheel slip rate, speed and deceleration (S3200, S3300)

[0051] The processor (110) can check whether the wheel speed recovery time, during which the wheel speed recovers from an abnormal value, exceeds the wheel speed recovery threshold value (S3400).

[0052] The processor (110) determines the target wheel slip rate based on the road surface if the wheel speed restoration time does not exceed the wheel speed restoration reference value, and conversely, determines the target wheel slip rate based on the road surface and the determined wheel slip rate if the wheel speed restoration time exceeds the wheel speed restoration reference value (S3500, S3600). That is, if the wheel speed restoration time exceeds the wheel speed restoration reference value, compensation can be performed on the existing wheel slip rate that was determined based on the road surface, and the wheel slip rate compensation at this time can be performed based on the determined wheel slip rate (S3500).

[0053] The processor (110) can set the determined wheel slip rate as the wheel slip rate when the wheel speed restoration time first exceeds the wheel speed restoration reference value (S3500).

[0054] The processor (110) can determine the target wheel slip rate as the first and second target wheel slip rates.

[0055] The processor (110) can determine the target wheel speed based on the target wheel slip rate (S3700). Specifically, the processor (110) can determine the first and second target wheel speeds based on the first and second target wheel slip rates.

[0056] The processor (110) can determine whether to reduce, maintain, or increase the pressure of the wheel based on a comparison between the wheel speed and the target wheel speed (S3800).

[0057] The processor (110) can generate a pressure increase signal if the wheel speed is greater than the first target wheel speed, generate a maintenance signal if the wheel speed is less than the first target wheel speed and greater than the second target wheel speed, and generate a pressure decrease signal if the wheel speed is less than the second target wheel speed.

[0058] The processor (110) can transmit a signal to the wheel braking device (130) to reduce, maintain, or increase the pressure of the wheel (S3900).

[0059] FIG. 5 relates to a wheel pressure control operation that may occur after a target wheel slip rate compensation (S3500) is performed as the wheel speed restoration time in FIG. 4 exceeds the wheel speed restoration reference time (S3400).

[0060] Referring to FIGS. 4 and 5, when the processor (110) compensates for the target wheel slip rate based on the wheel slip rate determined by FIG. 4 (S3500), the probability of determining the pressure increase of the wheel (S3800) can be increased compared to the case where the target wheel slip rate is determined based only on the road surface (S3600).

[0061] For example, when the processor (110) determines the pressure increase of the wheel by compensating for the target wheel slip rate according to the previous wheel pressure control operation (Fig. 4) (S3600, S3800), it initializes the wheel speed restoration reference value and can check whether the current wheel slip rate determined according to the wheel pressure control operation of Fig. 5 exceeds the previous compensated wheel slip rate compensated according to Fig. 4.

[0062] The processor (110) may determine that the compensation wheel slip rate is the same as the current wheel slip rate if the current wheel slip rate does not exceed the previous compensation wheel slip rate, and conversely, may determine that the compensation wheel slip rate is the same as the previous compensation wheel slip rate if the current wheel slip rate exceeds the previous compensation wheel slip rate. That is, the processor (110) may determine the minimum value between the current wheel slip rate and the previous compensation wheel slip rate as the compensation wheel slip rate.

[0063] The processor (110) can determine the target wheel slip rate based on the determined compensation wheel slip rate and the road surface. Specifically, the processor (110) can determine the total sum of the determined compensation wheel slip rate and the wheel slip rate according to the road surface as the target wheel slip rate.

[0064] Afterward, the processor (110) determines the target wheel speed based on the road surface and the compensation wheel slip ratio as shown in FIG. 4 (S3700), and determines whether to reduce, maintain, or increase the pressure of the wheel based on a comparison between the wheel speed and the target wheel speed, thereby controlling the wheel braking device (S3800, S3900).

[0065] As described above, the vehicle braking control device (100) can determine the target wheel slip rate based on the recovery time and secure the wheel braking force of the vehicle on an undetermined special irregular road surface to increase vehicle driving stability.

[0066] As described above, the disclosed embodiments have been explained with reference to the attached drawings. Those skilled in the art will understand that the present invention may be practiced in forms different from the disclosed embodiments without changing the technical concept or essential features of the present invention. The disclosed embodiments are illustrative and should not be interpreted restrictively. Explanation of the symbols

[0067] 100: Vehicle braking control unit 110: Processor 120: Wheel speed sensor 130: Wheel braking system 11: 1st wheel speed 12: Second wheel speed 20: Vehicle speed 31: 1st Objective Wheel Speed 32: Second Objective Wheel Speed 31a: Target wheel speed before the first compensation 32a: Target wheel speed before 2nd compensation 31b: Target wheel speed after the first compensation

Claims

Claim 1 A wheel speed sensor that measures the wheel speed of a vehicle; a wheel braking device that controls the braking pressure of the wheel; A vehicle braking control device comprising a processor that determines a wheel slip ratio, the speed and deceleration of the vehicle based on the wheel speed, determines a wheel speed restoration reference value based on the wheel slip ratio, speed and deceleration, and if the wheel speed restoration time in which the wheel speed recovers from an abnormal value exceeds the wheel speed restoration reference value, determines a target wheel slip ratio based on the determined wheel slip ratio, determines a road surface based on the deceleration of the vehicle, determines the target wheel slip ratio based on the road surface, determines a first and second target wheel slip ratio based on the road surface, determines a first and second target wheel speed based on the first and second target wheel slip ratios, generates a pressure increase signal if the wheel speed is greater than the first target wheel speed, generates a maintenance signal if the wheel speed is less than the first target wheel speed and greater than the second target wheel speed, generates a pressure decrease signal if the wheel speed is less than the second target wheel speed, and transmits a pressure decrease, maintenance, or pressure increase signal of the wheel to the wheel braking device. Claim 2 In claim 1, the vehicle braking control device, wherein the processor initializes the wheel speed restoration time and the wheel speed restoration reference value when transmitting a signal for depressurization or maintenance of the wheel to the wheel braking device. Claim 3 In claim 1, the processor is a vehicle braking control device that determines the wheel speed restoration reference value based on the maximum wheel slip ratio, where the wheel slip ratio is the maximum value. Claim 4 In paragraph 3, the processor is a vehicle braking control device that counts the wheel speed recovery time from the maximum wheel slip rate. Claim 5 delete Claim 6 delete Claim 7 A vehicle braking control method comprising determining a wheel slip ratio, vehicle speed, and deceleration based on wheel speed, determining a wheel speed restoration reference value based on the wheel slip ratio, speed, and deceleration, and if the wheel speed restoration time in which the wheel speed recovers from an abnormal value exceeds the wheel speed restoration reference value, determining a target wheel slip ratio based on the determined wheel slip ratio, determining a road surface based on the vehicle deceleration, determining the target wheel slip ratio based on the road surface, determining a first and second target wheel slip ratio based on the road surface, determining a first and second target wheel speed based on the first and second target wheel slip ratios, generating a pressure increase signal if the wheel speed is greater than the first target wheel speed, generating a maintenance signal if the wheel speed is less than the first target wheel speed and greater than the second target wheel speed, generating a pressure decrease signal if the wheel speed is less than the second target wheel speed, and transmitting a pressure decrease, maintenance, or pressure increase signal of the wheel to a wheel braking device.

Images