DE102017106150A1 - Parking brake control method and apparatus - Google Patents

Abstract

The present disclosure relates to a parking brake control method and apparatus. The method includes: determining if the current gear of a vehicle is a P-gear, if the speed of the vehicle is less than a predetermined speed threshold, the ambient humidity is higher than a predetermined threshold of humidity, and if a button of the electronic parking brake of the vehicle is pulled up is; starting a timing when it is determined that the current gear of the vehicle is the P-speed; and enabling an EPB system when a predetermined interval time is reached such that the EPB system controls release of a caliper for a predetermined release time and then again pressing the caliper. In this case, the possibility of sticking between a brake friction pad and a brake disc, which is caused by too long clamping of the brake disc by the caliper, can be reduced.

Description

Field of the invention

The present disclosure relates to the field of vehicle control, and more particularly to a parking brake control method and apparatus.

General state of the art

At present, with the rapid development of electronic technology, the intelligence levels of vehicles continue to increase. An electric parking brake system (EPB system) is gradually replacing the traditional mechanical hand brake system.

The EPB system is based on the technology of integrating a temporary brake into a driving process with a long-term braking after parking and providing a parking brake in an electronic control mode, and its static parking brake functions usually include: a reduced pressing force and high-temperature pressing functions and rolling away pressing.

Brief description of the invention

The object of the present disclosure is to provide a simple and practical parking brake control method and apparatus.

To achieve the above object, the present disclosure provides a parking brake control method. The method includes: determining if the current gear of a vehicle is a P-gear, if the speed of the vehicle is less than a predetermined speed threshold, the ambient humidity is greater than a predetermined threshold of humidity, and if a button of the electronic parking brake of the vehicle is pulled up; starting a timing when it is determined that the current gear of the vehicle is the P-speed; and enabling an EPB system when a predetermined interval time is reached such that the EPB system controls release of a caliper for a predetermined release time and then again pressing the caliper.

Optionally, the step of starting a timing, when it is determined that the current gear of the vehicle is the P-speed, includes: determining whether the slope of a road on which the vehicle is located is less than a predetermined gradient threshold, when it is determined that the current gear of the vehicle is the P-speed; and starting a time-out if it is determined that the slope of the roadway on which the vehicle is located is less than the gradient threshold.

Optionally, the method further includes: determining if the vehicle has come into contact with rain during the last ignition cycle when it is determined that the vehicle's current gear is the P-gear; wherein the step of activating the EPB system, when the predetermined interval time is reached, such that the EPB system controls the release of a caliper for a predetermined release time and then again pressing the caliper, comprises: enabling the EPB system when determined determining that the vehicle has not encountered rain during the last ignition cycle, and when a predetermined first interval time is reached, such that the EPB system controls the release of the caliper for the predetermined release time and then again pressing the caliper; and enabling the EPB system when it is determined that the vehicle has encountered rain during the last ignition cycle and when a predetermined second interval time is reached, such that the EPB system releases the brake caliper for the predetermined release time and then again pressing the caliper controls, wherein the first interval time is longer than the second interval time.

Optionally, the step of starting a timing, when it is determined that the current gear of the vehicle is the P-speed, includes: sending a timing request to a mobile terminal that can connect the vehicle through a wireless network when it is determined the current gear of the vehicle is the P-gear, so that the mobile terminal starts timing; wherein the step of activating the EPB system, when the predetermined interval time is reached, such that the EPB system controls the release of a caliper for a predetermined release time and then again pressing the caliper, comprises: receiving an activation message subsequent to the predetermined one Interval time is sent by the mobile terminal; and enabling the EPB system in response to the activation message such that the EPB system controls the release of the caliper for the predetermined release time and then again pressing the caliper.

Optionally, after the step of activating the EPB system, when a predetermined interval time is reached, the method includes causing the EPB system to control the release of a caliper for a predetermined release time and then again pressing the caliper, further comprising: controlling the EPB System to switch to a roll-off pressing mode.

Optionally, the method further includes: activating an electronic stability control system of the vehicle when the predetermined interval time is reached, such that the electronic stability control system detects the longitudinal acceleration of the vehicle, wherein the contact force is determined in the roll-over Anpressmodus according to the detected longitudinal acceleration.

$$\delta =tg\theta$$

wobei F_N die Anpresskraft, die während des Wegroll-Anpressens durch den Bremssattel auf die Bremsscheibe angewandt wird, darstellt; F₀ die Anpresskraft, die vor dem Wegroll-Anpressen durch den Bremssattel auf die Bremsscheibe angewandt wird, darstellt; δ die Steigung der Fahrbahn, auf welcher sich das Fahrzeug befindet, darstellt; θ einen eingeschlossenen Winkel zwischen der Fahrbahn, auf welcher sich das Fahrzeug befindet, und der horizontalen Ebene darstellt; und ε ein Variationsverhältnis der Längsbeschleunigung des Fahrzeugs zur Erdbeschleunigung darstellt. Optionally, the contact force in roll-off mode meets the following formula: $$F_N=F_0*\left(\delta +\epsilon \right)/\delta$$

$$\delta =tG\theta$$

where F _{N represents} the contact force applied to the brake disc during rolling-contact pressing by the caliper; F _{0 represents} the contact force applied to the brake disc by the caliper before rolling-off; δ represents the slope of the roadway on which the vehicle is located; θ represents an included angle between the road on which the vehicle is located and the horizontal plane; and ε represents a variation ratio of the longitudinal acceleration of the vehicle to the gravitational acceleration.

The present disclosure further provides a parking brake control device. The apparatus includes: a gear determination module for determining whether the current gear of the vehicle is a P-gear, when the speed of the vehicle is less than a predetermined speed threshold, the ambient humidity is higher than a predetermined humidity threshold, and if a button of the electronic Parking brake of the vehicle is pulled up, is configured; a time-out module configured to start a timing when it is determined that the current gear of the vehicle is the P-speed; and a first activation module configured to activate an EPB system when a predetermined interval time is reached such that the EPB system controls release of a caliper for a predetermined release time and then again pressing the caliper.

Optionally, the timing module includes: a pitch determination sub-module configured to determine whether the grade of a lane on which the vehicle is located is less than a predetermined pitch threshold when it is determined that the current gear of the vehicle is the P-speed ; and a timing sub-module configured to start a timing when the slope determination sub-module determines that the slope of the lane on which the vehicle is located is less than the slope threshold.

Optionally, the apparatus further includes: a rain determination module coupled to the gear determination module for determining whether the vehicle has come into contact with rain during the last ignition cycle when the gear determination module determines that the current gear of the vehicle is the P-gear , is configured; wherein the first activation module includes: a first activation sub-module configured to activate the electronic parking brake system when the rain determination module determines that the vehicle has not encountered rain during the last ignition cycle and when a predetermined first interval time is reached, such that the EPB System controls the release of the caliper for the predetermined release time and then again pressing the caliper is configured; and a second activation sub-module operable to activate the electronic parking brake system when the rain determination module determines that the vehicle has encountered rain during the last ignition cycle and when a predetermined second interval time is reached, such that the EPB system releases the brake caliper the predetermined release time and then again pressing the caliper controls, wherein the first interval time is longer than the second interval time is configured.

Using the above technical solutions, the EPB system is used for braking, and the brake caliper of the EPB system becomes the vehicle's speed for temporary release after a period commencing with parking when the vehicle is in P-speed is low and when the ambient humidity is high, controlled, in which case a delayed release function of the EPB system can be realized and thus the possibility of sticking between a brake friction pad and a brake disc caused by too long clamping the brake disc by the caliper is reduced.

Other features and advantages of the present disclosure are illustrated in detail in the following embodiments.

list of figures

• 1 ein Flussdiagramm eines Parkbremsensteuerungsverfahrens bereitgestellt durch eine beispielhafte Ausführungsform;
• 2 ein Flussdiagramm eines Parkbremsensteuerungsverfahrens bereitgestellt durch eine weitere beispielhafte Ausführungsform;
• 3 ein Flussdiagramm eines Parkbremsensteuerungsverfahrens bereitgestellt durch noch eine weitere beispielhafte Ausführungsform;
• 4 ein Flussdiagramm eines Parkbremsensteuerungsverfahrens bereitgestellt durch noch eine weitere beispielhafte Ausführungsform;
• 5 ein Flussdiagramm eines Parkbremsensteuerungsverfahrens bereitgestellt durch noch eine weitere beispielhafte Ausführungsform;
• 6 ein Flussdiagramm eines Parkbremsensteuerungsverfahrens bereitgestellt durch noch eine weitere beispielhafte Ausführungsform;
• 7 ein Strukturblockdiagramm einer Parkbremsensteuerungsvorrichtung bereitgestellt durch eine beispielhafte Ausführungsform.

The accompanying drawings are provided to provide a further understanding of the present disclosure, are incorporated in and constitute a part of the specification, and are intended to be illustrative of the present disclosure along with the following embodiments, but not limitation of the present disclosure. In the accompanying drawings:

• 1 a flowchart of a parking brake control method provided by an exemplary embodiment;
• 2 a flowchart of a parking brake control method provided by another exemplary embodiment;
• 3 a flowchart of a parking brake control method provided by yet another exemplary embodiment;
• 4 a flowchart of a parking brake control method provided by yet another exemplary embodiment;
• 5 a flowchart of a parking brake control method provided by yet another exemplary embodiment;
• 6 a flowchart of a parking brake control method provided by yet another exemplary embodiment;
• 7 3 is a structural block diagram of a parking brake control device provided by an exemplary embodiment.

Detailed description of the embodiments

Embodiments of the present disclosure are illustrated below in detail in combination with the accompanying drawings. It should be understood that the embodiments described herein are merely illustrative and explanatory of the present disclosure rather than limiting the present disclosure.

1 FIG. 10 is a flowchart of a parking brake control method provided by an exemplary embodiment. As in 1 As shown, the method includes the following steps.

In step S11, it is determined whether the current gear of a vehicle is a P-speed, when the speed of the vehicle is less than a predetermined speed threshold, the ambient humidity is higher than a predetermined threshold, and when a button of the electronic parking brake of the vehicle is pulled up ,

When the speed of the vehicle is less than the predetermined speed threshold, the vehicle may be considered to be approximately static at present. For example, the speed of the vehicle may be calculated by detecting electronic pulses used to indicate a wheel turning angle. Whether the electronic parking brake button is raised can be detected by an EPB system.

When the ambient humidity is higher than the predetermined humidity threshold, it can be considered that the risk of sticking between a brake friction pad and a brake disk after parking under the current environmental conditions is high, and it is necessary to temporarily brake a caliper after parking for a period of time to reduce the risk of sticking between the brake friction pad and the brake disc. Conversely, if the ambient humidity is less than the predetermined humidity threshold, it can be expected that the risk of sticking between the brake friction pad and the brake disk after parking under the current environmental conditions will be low, so that the caliper will not have to be released until the next drive ,

If the speed of the vehicle is less than the predetermined speed threshold and if the electronic parking brake button is raised, this indicates that a driver intends to park and that the vehicle is substantially static. At this time, the caliper can be controlled by the EPB system to apply a pressing force to the brake disk to cause the brake disk to press the brake friction pad so as to control the vehicle for parking.

For example, the current gear information may be obtained by an automatic transmission.

In step S12, a timing is started when it is determined that the current gear of the vehicle is the P-speed.

As described below, the delayed release function of the present disclosure requires a momentary release of the caliper. For safety reasons, the caliper can only be released for a short time in the case of P-gear. In this way, even if the brake caliper is released for a short time, there is a certain brake guarantee and no accident is caused. A timeout device may be configured in the vehicle so that a timeout may still occur after the EPB system has entered a sleep state.

In step S13, the EPB system is activated when a predetermined interval time is reached so that the EPB system controls the release of the caliper for a predetermined release time and then again pressing the caliper.

Typically, when the vehicle is turned off, the EPB system shuts down after a short period of time (eg, 10 minutes), and it requires a relatively long (eg, 3 days) interval time (an interval time in which sticking can take place) for the release of the caliper; therefore, when the caliper needs to be released, the EPB system is idle, and thus the EPB system must first be activated to control the release of the caliper.

The above interval time and release time can be determined by experiment or experience. For example, after a period of 72 hours, the caliper is released for 5 seconds and then pressed again.

It can be understood that, in step S13, the EPB system may also be periodically activated when the predetermined interval time is periodically reached, such that the EPB system controls the release of the caliper for the predetermined release time and then again pressing the caliper. For example, the caliper is always released after 72 hours for 5 seconds and then pressed again.

Using the above technical solutions, the EPB system is used for braking, and the brake caliper of the EPB system becomes the vehicle's speed for temporary release after a period commencing with parking when the vehicle is in P-speed is low and when the ambient humidity is high, controlled, in which case a delayed release function of the EPB system can be realized, and thus the possibility of adhesion between the brake friction pad and a brake disc caused by too long clamping the brake disc by the caliper is reduced.

As described above, the present disclosure reduces the possibility of sticking between the brake friction pad and the brake disc by the momentary release of the caliper. If the current gear is not P-speed, rolling off may be caused due to the absence of mechanical braking and potential safety hazards may arise if the caliper is disengaged on a higher grade roadway. Therefore, when it is determined that the current gear of the vehicle is not the P-speed, the EPB system can be directly controlled to shift to a roll-off pressing mode.

In other words, if the current gear is not the P-gear, the above-mentioned delayed release can not be performed for safety reasons, and the rolling-contact pressing mode is performed directly. This avoids accidents caused by slipping of the vehicle resulting from the loosening, and improves the safety of the vehicle.

It can be considered that, when the interval time is reached and no release occurs, the adhesion between the brake friction pad and the brake disk is likely to take place. The length of the interval time is influenced by several factors, e.g. Temperature, humidity, friction lining material and so on. The length of the interval time can be determined by specific conditions.

In one embodiment of the present disclosure, the step (step S12) of starting a timing when it is determined that the current gear of the vehicle is the P-speed may include: determining whether the slope of a road on which the Vehicle is less than a predetermined slope threshold, if it is determined that the current gear of the vehicle is the P-gear; and starting a time-out if it is determined that the slope of the roadway on which the vehicle is located is less than the gradient threshold.

It can be considered that a braking effect can be achieved by using only the P-speed, even without electronic braking, when the slope is less than the predetermined gradient threshold. In contrast, it is considered that rolling is possible when the slope is greater than the predetermined gradient threshold and when only the P-speed is used and the electronic braking is not used. The slope threshold can be obtained by experience or experiment.

If braking depends solely on P-speed, the greater the grade, the worse the safety of braking; therefore, in the embodiment, the above-mentioned delayed release can not be performed, and the roll-off pressing mode can be performed directly when the slope of the road is greater than the gradient threshold (e.g., 5%).

That is, the delayed release function of the present disclosure may be performed when the speed of the vehicle is less than the predetermined speed threshold, the electronic parking brake button is raised, the current gear is the P-gear, the ambient humidity is higher than the predetermined humidity threshold, and the slope is less than the predetermined slope threshold; This can cause accidents caused by the vehicle rolling away can be avoided, and the safety of the vehicle can be improved.

2 FIG. 10 is a flowchart of a parking brake control method provided by another exemplary embodiment. As in 2 , based on 1 12, the method may further include step S12 '.

In step S12 ', it is determined whether the vehicle has come into contact with rain during the last ignition cycle when it is determined that the current gear of the vehicle is the P-speed.

In the embodiment, the step of enabling the EPB system (step S13) when a predetermined interval time is reached so that the EPB system controls the release of a caliper for a predetermined release time and then again pressing the caliper may include the following steps.

In step S131, the EPB system is activated when it is determined that the vehicle has not encountered rain during the last ignition cycle, and when a predetermined first interval time is reached, such that the EPB system releases the brake caliper for the predetermined one Release time and then again pressing the caliper controls.

In step S132, the EPB system is activated when it is determined that the vehicle has encountered rain during the last ignition cycle and when a predetermined second interval time is reached, such that the EPB system releases the caliper for the predetermined release time and then again pressing the caliper controls, wherein the first interval time is longer than the second interval time.

That is, the interval time is determined according to whether the vehicle comes into contact with rain during the last ignition cycle. If the vehicle comes into contact with rain during the last ignition cycle, it is considered that the brake friction pad and brake disk may have become wet and a small amount of rainwater may remain thereon, and thus sticking may occur within a short period of time. Conversely, if the vehicle does not come into contact with rain during the last ignition cycle, it is considered that the brake friction pad and the brake disk have not become wet, and thus the possibility of sticking within a short period of time is not so great. In view of this, in the case of no rain (the first interval time, for example, 168 hours), the interval time can be set longer than the interval time in the case of rain (the second interval time, for example, 72 hours).

Whether the vehicle has come into contact with rain during the last ignition cycle can be detected by a rain sensor or a windshield wiper. For example, if it is detected that the operation time of the windshield wiper reaches a predetermined time, it may be determined that the vehicle has come in contact with rain in the current ignition process.

In the embodiment, different interval times are set according to the presence or absence of rain; thereby the interval of release of the caliper is more suitable for the actual conditions and better fulfills the actual needs.

In the above embodiment, the timing may be performed by a timer installed in the vehicle, and the timing may also be performed by a user terminal that can communicate with the vehicle to reduce the power consumption of the vehicle.

3 FIG. 10 is a flowchart of a parking brake control method provided by yet another exemplary embodiment. As in 3 , based on 1 12, the step (step S12) of starting a timing when it is determined that the current gear of the vehicle is the P-speed may include the following steps.

In step S121, a timing request is sent to a mobile terminal that can connect the vehicle through a wireless network when it is determined that the current gear of the vehicle is the P-gear, so that the mobile terminal starts timing.

In the embodiment, the step of activating the EPB system (step S13), when a predetermined interval time is reached, such that the EPB system controls the release of a caliper for a predetermined release time and then again pressing the caliper, may include the following steps.

In step S133, an activation message sent after the predetermined interval time by the mobile terminal is received.

In step S134, the EPB system is activated in response to the activation message so that the EPB system controls the release of the caliper for the predetermined release time and then again pressing the caliper.

If four conditions are met, namely that the speed of the vehicle is less than the predetermined speed threshold, the ambient humidity is higher than the predetermined humidity threshold, the electronic parking brake button is raised, and the vehicle's current gear is not P-speed, then EPB system or other devices to send the timing request to the mobile device (for example, a mobile phone, a computer, a tablet, a clock or the like). Then the EPB system can enter a sleep mode according to a normal procedure.

The mobile terminal may start timing when it receives the timing request, and may send the activation message to the EPB system upon reaching the interval time. The interval time may be a preset time, or the timing request may include the information of the interval time, and the mobile terminal sends the activation message according to the obtained information of the interval time after receiving the information of the interval time.

The EPB system may be set to self-activate upon receipt of the activation message and to control the release of the caliper for the predetermined release time and then again to press the caliper. The EPB system can also be activated by other devices. Thereafter, the EPB system may return to sleep after a predetermined time.

In this embodiment, considering that some vehicles have the functions of communicating with the mobile terminal (e.g., a smart phone) (e.g., BLINK of BORGWARD), the timing may be performed by the mobile terminal to decrease the power consumption of the vehicle.

In addition, the EPB system may also send a vehicle movement request to the mobile terminal after the caliper has been re-pressed to notify a driver to move the vehicle so as to reduce the possibility of sticking between the brake friction pad and the brake disc.

4 FIG. 10 is a flowchart of a parking brake control method provided by yet another exemplary embodiment. As in 4 , based on 1 The method, after the step (step S13) of activating the EPB system when a predetermined interval time is reached, such that the EPB system controls the release of a caliper for a predetermined release time and then again pressing the caliper, further Include step S14.

In step S14, the EPB system is controlled to switch to a roll-off pressing mode.

In view of the fact that some deposits may fall out of the gap between the brake friction pad and the brake disc when the caliper is released for a short time or for other reasons, the vehicle may roll due to insufficient contact force. Therefore, the EPB system, in the embodiment of 4 after the momentary release of the caliper, switch to the roll-off pressing mode so as to eliminate the potential safety risks caused by rolling due to loosening. Thereafter, the EPB system may switch back to sleep after the predetermined time.

In the associated technology of the rolling-contact pressing function, the contact pressure equals the original contact force. In the present disclosure, the pressing force may also be determined according to a longitudinal acceleration that is detected during the rolling away of the vehicle so as to adapt to specific conditions. 5 FIG. 10 is a flowchart of a parking brake control method provided by yet another exemplary embodiment. As in 5 , based on 4 Further, after the step (step S12) of starting a timing when it is determined that the current gear of the vehicle is the P-speed, the method may further include step S13 '.

In step S13 ', an electronic stability control system of the vehicle is activated when the predetermined interval time is reached so that the electronic stability control system detects the longitudinal acceleration of the vehicle. The contact force in the rolling contact pressure mode is determined according to the detected longitudinal acceleration.

The longitudinal acceleration of the vehicle can be detected by the electronic stability control system. The electronic stability control system may be activated to provide the longitudinal acceleration at the same time as the EPB system is activated. Since the detected longitudinal acceleration reflects the specific condition in the case of vehicle rolling away, the pressing force is determined according to the longitudinal acceleration, so that a better adaptation to the actual conditions can be made and the size of the pressing force is correct.

It can be understood that the electronic stability control system may not be activated, and a longitudinal acceleration sensor may be separately external to the electronic Stability control system may be arranged to detect the longitudinal acceleration.

wobei F_N die Anpresskraft, die während des Wegroll-Anpressens durch den Bremssattel auf die Bremsscheibe angewandt wird, darstellt; F₀ die Anpresskraft, die vor dem Wegroll-Anpressen durch den Bremssattel auf die Bremsscheibe angewandt wird, darstellt; δ die Steigung der Fahrbahn, auf welcher sich das Fahrzeug befindet, darstellt; und ε ein Variationsverhältnis der Längsbeschleunigung des Fahrzeugs zur Erdbeschleunigung darstellt. Die Längsbeschleunigung des Fahrzeugs kann durch den Längsbeschleunigungssensor in dem elektronischen Stabilitätskontrollsystem erkannt werden.In an embodiment of the present disclosure, the pressing force in the rolling contact pressing mode may satisfy the following formula: $$F_N=F_0*\left(\delta +\epsilon \right)/\delta$$

where F _{N represents} the contact force applied to the brake disc during rolling-contact pressing by the caliper; F _{0 represents} the contact force applied to the brake disc by the caliper before rolling-off; δ represents the slope of the roadway on which the vehicle is located; and ε represents a variation ratio of the longitudinal acceleration of the vehicle to the gravitational acceleration. The longitudinal acceleration of the vehicle can be detected by the longitudinal acceleration sensor in the electronic stability control system.

wobei θ einen eingeschlossenen Winkel zwischen der Fahrbahn, auf welcher sich das Fahrzeug befindet, und der horizontalen Ebene darstellt; m die Masse des Fahrzeugs darstellt, und g die Erdbeschleunigung darstellt.Specifically, according to a force analysis, the pressing force F ₀ before the vehicle rolls away may be as follows: $$F_0=mG*\text{sin}\theta$$

where θ represents an included angle between the roadway on which the vehicle is located and the horizontal plane; m represents the mass of the vehicle, and g represents the gravitational acceleration.

wobei die Längsbeschleunigung a durch das elektronische Stabilitätskontrollsystem eines Fahrzeugkörpers erkannt werden kann (zum Beispiel das elektronische Stabilitätsprogramm, bezeichnet als ESP, der Firma Bosch). Wenn das Fahrzeug zum Beispiel an einer Steigung statisch ist und der eingeschlossene Winkel zwischen der Fahrbahn und der horizontalen Ebene θ ist, kann der numerische Wert, der durch das ESP ausgegeben wird, als K₀ = g sin θ angezeigt werden. Wenn die Beschleunigung a im Fall eines Wegrollens erzeugt wird, kann der numerische Wert, der durch das ESP ausgegeben wird, als K₁ = g sin θ - a angezeigt werden. Die Beschleunigung a des Wegrollens kann durch die Differenz zwischen den obigen beiden numerischen Werten, die durch das ESP ausgegeben werden, erhalten werden.In the case of rolling away of the vehicle, the vehicle generates a downward acceleration a along the road surface (ie, the longitudinal acceleration), and when the pressing force F _N satisfies the following formula (3), a balance of power of the vehicle after repressing can be achieved: $$F_N=mG*\text{sin}\theta +ma$$

wherein the longitudinal acceleration a can be detected by the electronic stability control system of a vehicle body (for example, the electronic stability program, referred to as ESP, the Bosch company). For example, if the vehicle is static on a slope and the included angle between the roadway and the horizontal plane is θ, the numerical value output by the ESP may be displayed as K ₀ = g sin θ. When the acceleration a is generated in the case of rolling away, the numerical value output by the ESP can be displayed as K ₁ = g sin θ-a. The acceleration a of rolling away can be obtained by the difference between the above two numerical values output by the ESP.

According to the definition of a slope, the relationship of the included angle θ between the road on which the vehicle is located and the horizontal plane and the slope δ of the road can be expressed as δ = tg θ. If θ is low (for example less than a predetermined angle threshold) then: $$\delta =tG\theta \approx \text{sin}\theta$$

ε is set as the variation ratio of the longitudinal acceleration of the vehicle to the gravitational acceleration. Since the acceleration of the vehicle before the rolling-contact pressing is zero, the variation of the longitudinal acceleration of the vehicle in the case of rolling away of the vehicle may be the downward longitudinal acceleration a along the roadway. Then: $$\epsilon =a/G$$

In this way, the formula (1) according to the above formulas ( 2 ) to (5) are derived.

In the embodiment, a control strategy for the pressing force is provided in the rolling contact pressing function, and the magnitude of the pressing force can be determined according to the actual conditions of rolling away, so that the size of the pressing force better meets the actual needs.

6 FIG. 10 is a flowchart of a parking brake control method provided by yet another exemplary embodiment. The procedure, as in 6 shown is the combination of several embodiments mentioned above.

It can be understood that if it is determined that the vehicle has not come in contact with rain, the transmitted timing request may include the information of the first interval time, and if it is determined that the vehicle has come in contact with rain, the transmitted one Timing request may include the information of the second interval time. Other specific steps are not described in detail herein.

The present disclosure further provides a parking brake control device. 7 FIG. 10 is a structural block diagram of a parking brake control device provided by an exemplary embodiment. FIG. As in 7 shown, the parking brake control device 10 one Transitional provision module 11 , a time-out module 12 and a first activation module 13.

The gear determination module 11 is configured to determine whether the current gear of the vehicle is a P-gear, when the speed of the vehicle is less than a predetermined speed threshold, the ambient humidity is higher than a predetermined threshold of humidity, and when a button of the electronic parking brake of the vehicle is pulled up ,

The timeout module 12 is configured to start timing when through the gear determination module 11 it is determined that the current gear of the vehicle is the P-gear.

The first activation module 13 is with the timeout module 12 connected and configured to activate an EPB system when a predetermined interval time is reached, so that the EPB system controls the release of a caliper for a predetermined release time and then again pressing the caliper.

Optionally, the timeout module 12 a slope determination sub-module and a timing sub-module.

The slope determination sub-module is configured to determine whether the slope of a lane on which the vehicle is located is less than a predetermined slope threshold, if it is determined that the current gear of the vehicle is the P-speed.

The timing sub-module is configured to start timing if the grade determination sub-module determines that the grade of the road on which the vehicle is located is less than the grade threshold.

Optionally, the device can 10 further include a rain determination module. The rain determination module is associated with the gear determination module 11 configured and configured to determine whether the vehicle has come into contact with rain during the last ignition cycle when the gear determination module 11 determines that the current gear of the vehicle is the P-gear.

In the embodiment, the first activation module 13 include a first activation sub-module and a second activation sub-module.

The first activation sub-module is configured to activate the EPB system when the rain determination module determines that the vehicle has not encountered rain during the last ignition cycle and when a predetermined first interval time is reached, such that the EPB system releases the brake caliper for the predetermined release time and then again pressing the caliper controls.

The second activation sub-module is configured to activate the EPB system when the rain determination module determines that the vehicle has encountered rain during the last ignition cycle and when a predetermined second interval time is reached, such that the EPB system releases the brake caliper the predetermined release time and then again pressing the caliper controls, wherein the first interval time is longer than the second interval time.

Optionally, the timeout module 12 include a transmit submodule. The transmission sub-module is configured to send a timing request to a mobile terminal that can connect the vehicle through a wireless network when it is determined that the current gear of the vehicle is the P-gear, so that the mobile terminal starts timing.

In the embodiment, the first activation module 13 a receive sub-module and a third activation sub-module.

The reception sub-module is configured to receive an activation message sent after the predetermined interval time by the mobile terminal.

The third activation sub-module is connected to the receive sub-module and configured to activate the EPB system in response to the activation message such that the EPB system controls the release of the caliper for the predetermined release time and then again pressing the caliper.

Optionally, the device can 10 further include a control module.

The control module is with the first activation module 13 and configured to control the EPB system to switch to a roll-off apply mode.

Optionally, the device may further include a second activation module.

The second activation module is with the timeout module 12 connected and configured to activate an electronic stability control system of the vehicle when the predetermined interval time is reached, so that the electronic stability control system detects the longitudinal acceleration of the vehicle, wherein the contact pressure in the rolling contact pressure mode is determined according to the detected longitudinal acceleration.

$$\delta =tg\theta$$

wobei F_N die Anpresskraft, die während des Wegroll-Anpressens durch den Bremssattel auf die Bremsscheibe angewandt wird, darstellt; F₀ die Anpresskraft, die vor dem Wegroll-Anpressen durch den Bremssattel auf die Bremsscheibe angewandt wird, darstellt; δ die Steigung der Fahrbahn, auf welcher sich das Fahrzeug befindet, darstellt; θ einen eingeschlossenen Winkel zwischen der Fahrbahn, auf welcher sich das Fahrzeug befindet, und der horizontalen Ebene darstellt; und ε ein Variationsverhältnis der Längsbeschleunigung des Fahrzeugs zur Erdbeschleunigung darstellt.Optionally, the contact force in roll-off mode meets the following formula: $$F_N=F_0*\left(\delta +\epsilon \right)/\delta$$

$$\delta =tG\theta$$

where F _{N represents} the contact force applied to the brake disc during rolling-contact pressing by the caliper; F _{0 represents} the contact force applied to the brake disc by the caliper before rolling-off; δ represents the slope of the roadway on which the vehicle is located; θ represents an included angle between the road on which the vehicle is located and the horizontal plane; and ε represents a variation ratio of the longitudinal acceleration of the vehicle to the gravitational acceleration.

With respect to the apparatus in the above-mentioned embodiment, the specific modes in which the modules perform the operations have been described in detail in the embodiment relating to the method, and thus the descriptions thereof are not detailed herein.

Using the above technical solutions, the EPB system is used for braking, and the brake caliper of the EPB system becomes the vehicle's speed for temporary release after a period commencing with parking when the vehicle is in P-speed is low and when the ambient humidity is high, controlled, in which case a delayed release function of the EPB system can be realized and thus the possibility of sticking between a brake friction pad and a brake disc caused by too long clamping the brake disc by the caliper is reduced.

Preferred embodiments of the present disclosure have been described above in detail in combination with the accompanying drawings, however, the present disclosure is not limited to the specific details in the above embodiments; Various simple variations may be made to the technical solutions of the present disclosure within the scope of the technical concept of the present disclosure, and these simple variations are within the scope of the present disclosure.

It should also be understood that the specific technical features described in the above embodiments may be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present disclosure does not separately illustrate various possible combinations.

In addition, an arbitrary combination of various different embodiments of the present disclosure may be made so long as it does not conflict with the idea of the present disclosure, and is also to be considered as content disclosed in the present disclosure.

Claims (10)

A parking brake control method, characterized in that the method comprises: determining whether the current gear of a vehicle is a P-gear, if the speed of the vehicle is less than a predetermined speed threshold, the ambient humidity is higher than a predetermined threshold of humidity, and if a button the electronic parking brake of the vehicle is pulled up; Starting a timing when it is determined that the current gear of the vehicle is the P-speed; and activating an electronic parking brake system when a predetermined interval time is reached, such that the electronic parking brake system controls release of a caliper for a predetermined release time and then again pressing the caliper. Method according to Claim 1 characterized in that the step of starting a timing, when it is determined that the current gear of the vehicle is the P-speed, comprises: determining whether the slope of a roadway on which the vehicle is located is less than a predetermined one The grade threshold is when it is determined that the current gear of the vehicle is the P-speed; and starting a time lapse when it is determined that the slope of the roadway on which the vehicle is located is less than the gradient threshold. Method according to Claim 1 characterized in that the method further comprises: determining if the vehicle is in contact with rain during the last ignition cycle come when it is determined that the current gear of the vehicle is the P-gear; wherein the step of activating an electronic parking brake system, when a predetermined interval time is reached, such that the electronic parking brake system controls release of a caliper for a predetermined release time and then again pressing the caliper comprises: activating the electronic parking brake system when it is determined that Vehicle has not come into contact with rain during the last ignition cycle, and when a predetermined first interval time is reached, so that the electronic parking brake system controls the release of the caliper for the predetermined release time and then again pressing the caliper; and activating the electronic parking brake system when it is determined that the vehicle has come into contact with rain during the last ignition cycle, and when a predetermined second interval time is reached, such that the electronic parking brake system releases the caliper for the predetermined release time and then again pressing the brake caliper Brake caliper controls, wherein the first interval time is longer than the second interval time. Method according to Claim 1 characterized in that the step of starting a timing, when it is determined that the current gear of the vehicle is the P-speed, comprises: sending a timing request to a mobile terminal that can connect the vehicle through a wireless network when it is determined that the current gear of the vehicle is the P-gear, so that the mobile terminal starts timing; wherein the step of activating an electronic parking brake system, when a predetermined interval time is reached, such that the electronic parking brake system controls release of a caliper for a predetermined release time and then again pressing the caliper, comprises: receiving an activation message after the predetermined interval time mobile terminal is sent; and activating the electronic parking brake system in response to the activation message such that the electronic parking brake system controls release of the caliper for the predetermined release time and then again pressing the caliper. Method according to one of Claims 1 - 4 characterized in that, after the step of activating an electronic parking brake system, when a predetermined interval time is reached such that the electronic parking brake system controls release of a caliper for a predetermined release time and then again pressing the caliper, the method further comprises: controlling the electronic parking brake system, to switch to a rolling-contact mode. Method according to Claim 5 characterized in that, after the step of starting a timing, when it is determined that the current gear of the vehicle is the P-speed, the method further comprises: activating an electronic stability control system of the vehicle when the predetermined interval time is reached, so that the electronic stability control system detects the longitudinal acceleration of the vehicle, wherein the pressing force in the rolling-contact pressure mode is determined according to the detected longitudinal acceleration. Method according to Claim 6 , characterized in that the contact pressure in the rolling contact pressure mode fulfills the following formula: $$F_N=F_0*\left(\delta +\epsilon \right)/\delta$$

$$\delta =tG\theta$$

where F _{N represents} the contact force applied to the brake disc during rolling-contact pressing by the caliper; F _{0 represents} the contact force applied to the brake disc by the caliper before rolling-off; δ represents the slope of the roadway on which the vehicle is located; θ represents an included angle between the road on which the vehicle is located and the horizontal plane; and ε represents a variation ratio of the longitudinal acceleration of the vehicle to the gravitational acceleration. A parking brake control apparatus, characterized in that the apparatus comprises: a gear determination module for determining whether the current gear of the vehicle is a P-gear when the speed of the vehicle is less than a predetermined speed threshold, the ambient humidity is higher than a predetermined humidity threshold and when a key of the electronic parking brake of the vehicle is pulled up is configured; a time-out module configured to start a time-out when it is determined by the speed determination module that the current gear of the vehicle is the P-speed; and a first activation module coupled to the timeout module for activating an electronic parking brake system when a predetermined interval time is reached, such that the electronic parking brake system releases the brake caliper for a predetermined release time, and then again pressing the caliper controls is configured. Device after Claim 8 characterized in that the timing module comprises: a grade determination sub-module for determining whether the grade of a lane on which the vehicle is located is less than a predetermined grade threshold when it is determined that the current gear of the vehicle is the P- Gear is configured; and a timing sub-module configured to start a timing when the slope determination sub-module determines that the slope of the lane on which the vehicle is located is less than the slope threshold. Device after Claim 8 characterized in that the apparatus further comprises: a rain determination module connected to the gait determination module for determining if the vehicle has been in rain during the last ignition cycle when the gait determination module determines that the current gait of the vehicle the P-gear is configured; wherein the first activation module comprises: a first activation sub-module that is operable to activate the electronic parking brake system when the rain determination module determines that the vehicle has not encountered rain during the last ignition cycle and when a predetermined first interval time is reached, such that the electronic parking brake system Park brake system controls the release of the caliper for the predetermined release time and then again pressing the caliper is configured; and a second activation sub-module operable to activate the electronic parking brake system when the rain determination module determines that the vehicle has encountered rain during the last ignition cycle and when a predetermined second interval time is reached, such that the electronic parking brake system releases the brake caliper for predetermined release time and then again pressing the caliper controls, wherein the first interval time is longer than the second interval time is configured.

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