Vehicle braking control method, device, medium and vehicle

Abstract

This disclosure relates to a braking control method, device, medium, and vehicle for a vehicle, wherein the braking system of the vehicle includes a main braking system and an auxiliary braking system. The method includes: determining a fault in the main braking system; and, upon detecting a braking signal, performing anti-lock braking graded braking control on the vehicle through the auxiliary braking system, thereby improving the vehicle's braking control efficiency and the vehicle's safety and stability.

Description

Technical Field

[0001] The present disclosure relates to the technical field of vehicle braking control, and in particular, to a vehicle braking control method, device, medium and vehicle. Background Art

[0002] With the development of automobile technology, efficient and reliable braking systems are the key to ensuring vehicle safety. Electronic braking system technology has been widely used in the field of smart cars, which provides the advantages of fast response and precise control. However, the electronic braking system may fail due to electronic failure, software error or hardware damage, which may cause serious safety hazards in the event of emergency braking of the vehicle.

[0003] In related technical solutions, when a vehicle's main braking system fails, an auxiliary braking system is usually used for auxiliary braking. For example, the rear wheels are directly locked by the auxiliary braking system, and then the braking force of the auxiliary braking system is fine-tuned to bring the wheels to the locking limit. The existing solutions do not take different braking conditions into consideration, and the braking efficiency and vehicle stability are not high, and there are still safety hazards. Summary of the invention

[0004] The purpose of the present disclosure is to provide a vehicle braking control method, device, medium and vehicle to improve the safety and stability of vehicle braking.

[0005] To achieve the above objectives, in a first aspect, the present disclosure provides a braking control method for a vehicle, wherein the braking system of the vehicle includes a main braking system and an auxiliary braking system, and the method includes:

[0006] determining that the main brake system is faulty;

[0007] When a brake signal is detected, the auxiliary brake system performs anti-lock graded brake control on the vehicle.

[0008] Optionally, the stepwise anti-lock braking control of the vehicle by the auxiliary braking system includes:

[0009] Obtaining an actual slip rate of the vehicle during braking;

[0010] The braking force output by the auxiliary braking system is adjusted according to the actual slip ratio and the preset slip ratio.

[0011] Optionally, adjusting the braking force output by the auxiliary braking system according to the actual slip rate and the preset slip rate includes:

[0012] When the actual slip ratio is greater than the preset slip ratio, the braking force output by the auxiliary braking system is reduced until the actual slip ratio of the vehicle is less than or equal to the preset slip ratio.

[0013] Optionally, there are multiple auxiliary braking systems, and the stepwise anti-lock braking control of the vehicle by the auxiliary braking system includes:

[0014] determining a braking force requirement of the vehicle;

[0015] The braking force is distributed to at least one of the auxiliary braking systems according to the braking force requirement, so as to control the auxiliary braking system to output the corresponding braking force to perform graded braking on the vehicle.

[0016] Optionally, allocating braking force to at least one of the auxiliary braking systems according to the braking force requirement comprises:

[0017] In the event that the failure of the main brake system is a partial failure, the braking force demand is distributed to the non-failed part of the main brake system and to at least one of the auxiliary brake systems.

[0018] Optionally, the plurality of auxiliary brake systems include a motor brake system and a parking brake system, and the step of allocating the braking force demand to the non-faulty part of the main brake system and at least one of the auxiliary brake systems includes:

[0019] A target auxiliary braking system for providing braking force is selected from the plurality of auxiliary braking systems in sequence according to preset priorities, so that the braking force that can be provided by the non-faulty part of the main braking system and the target auxiliary braking system meets the braking force requirement of the vehicle.

[0020] Optionally, the multiple auxiliary braking systems include a parking brake system. When the braking force requirement includes a first braking force requirement triggered by the driver operating the parking brake system, the calling priority of the parking brake system in the preset priority level is higher than that of other auxiliary braking systems in the multiple auxiliary braking systems.

[0021] Optionally, the multiple auxiliary braking systems include a motor braking system, and when the braking force requirement is a second braking force requirement triggered by the driver operating the brake pedal, the calling priority of the motor braking system in the preset priority level is higher than other auxiliary braking systems in the multiple auxiliary braking systems.

[0022] Optionally, the main brake system is a hydraulic brake system, and the main brake system includes a plurality of hydraulic circuits and a mechanical circuit;

[0023] In the case that the multiple hydraulic circuits of the main brake system all fail, the non-failed part of the main brake system is the mechanical circuit in the main brake system;

[0024] In the event that the plurality of hydraulic circuit braking portions of the main brake system fail, the non-failed portion of the main brake system is the mechanical circuit and / or the non-failed hydraulic circuit brake in the main brake system.

[0025] Optionally, before determining the braking force requirement of the vehicle when a braking signal is detected, the method further includes:

[0026] In case a main brake system of the vehicle fails, obtaining a state of an accelerator pedal of the vehicle;

[0027] When the accelerator pedal state indicates that the effective opening of the accelerator pedal does not exceed a preset opening threshold, determining a system state of the auxiliary braking system of the vehicle;

[0028] When the system state of the auxiliary braking system of the vehicle is characterized as normal, the auxiliary braking system is controlled to enter a pre-clamping mode, and the pre-clamping mode is used to adjust the state of the brake of the auxiliary braking system to improve the braking response speed of the vehicle.

[0029] Optionally, the method further comprises:

[0030] When the auxiliary brake system of the vehicle is in the pre-clamping mode, obtaining a gear state and an accelerator pedal state of the vehicle;

[0031] When the gear state of the vehicle is a driving gear and the accelerator pedal state indicates that the effective opening of the accelerator pedal is greater than or equal to the preset opening threshold, controlling the auxiliary brake system to exit the pre-clamping mode;

[0032] When the gear state of the vehicle is a non-driving gear, or the accelerator pedal state indicates that the opening of the accelerator pedal is less than the preset opening threshold, the brake signal is continuously detected.

[0033] Optionally, the method further comprises:

[0034] When there is no abnormality in the main braking control system of the vehicle, or the vehicle is in a driving state and the accelerator pedal depth is greater than or equal to a preset opening threshold, or the braking signal is not detected and the vehicle speed is less than a preset vehicle speed threshold, stop braking control of the vehicle through the vehicle's auxiliary control system.

[0035] In a second aspect, the present disclosure provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method described in the first aspect of the present disclosure.

[0036] In a third aspect, the present disclosure provides a vehicle braking control device, comprising:

[0037] a memory having a computer program stored thereon;

[0038] A processor is used to execute the computer program in the memory to implement the method described in the first aspect of the present disclosure.

[0039] In a fourth aspect, the present disclosure provides a vehicle, comprising a processor and the braking control device of the vehicle provided in the third aspect of the present disclosure.

[0040] Through the above technical solution, in the event of a failure in the main braking system of the vehicle, the vehicle can be subjected to anti-lock braking control through the auxiliary braking system according to the current braking force demand of the vehicle. For example, different degrees of braking force can be applied to the vehicle through the auxiliary braking system according to the braking force demand, thereby avoiding locking of the vehicle wheels and improving the safety and stability of the vehicle.

[0041] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings:

[0043] Figure 1 The present invention is a flow chart showing a braking control method of a vehicle according to an exemplary embodiment.

[0044] Figure 2 The figure is a flow chart showing a method for controlling graded braking of a vehicle according to an exemplary embodiment.

[0045] Figure 3 The figure is a flow chart of a preprocessing method for vehicle braking control according to an exemplary embodiment.

[0046] Figure 4 It is a block diagram of a vehicle braking control device proposed by an exemplary embodiment of the present disclosure.

[0047] Figure 5 It is a block diagram of a vehicle proposed by an exemplary embodiment of the present disclosure. DETAILED DESCRIPTION

[0048] The specific implementation of the present disclosure is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described herein is only used to illustrate and explain the present disclosure, and is not used to limit the present disclosure.

[0049] Figure 1 is a flow chart of a vehicle braking control method according to an exemplary embodiment. Figure 1 As shown, the braking system of the vehicle includes a main braking system and an auxiliary braking system, and the method includes the following steps.

[0050] Step S101, determining that the main brake system is faulty.

[0051] It is worth mentioning that in order to quickly respond to the braking demand generated by the brake pedal, the vehicle's main braking system can be an electric signal braking system, that is, the vehicle braking is controlled by the electric signal of the ECU (Electronic Control Unit) instead of the traditional mechanical or hydraulic connection, such as IPB (Integrated Power Brake) or EMB (Electromechanical Braking). Therefore, the main braking system may fail to function completely or partially due to electronic failure, software error or hardware damage.

[0052] Among them, the vehicle's main braking system is used to respond to the vehicle's brake pedal signal to slow down or stop the vehicle. The braking torque output by the main braking system when there is no failure corresponds to the opening of the brake pedal. The vehicle's auxiliary braking system is used to provide additional braking force to the vehicle when the main braking system fails or the vehicle needs emergency braking.

[0053] In one embodiment, the vehicle's braking system has an MBB (Multi-level Backup of Braking) function. The MBB function is integrated in the vehicle's chassis controller. The chassis controller monitors and obtains the status of the main braking system in real time, and determines the fault condition of the main braking system. If the main braking system has no fault, the chassis controller does not activate the MBB function; when it is determined that the main braking system has a fault, the chassis controller activates the MBB function.

[0054] Step S102: When a braking signal is detected, anti-lock braking control is performed on the vehicle through the auxiliary braking system.

[0055] In one embodiment, after the chassis controller activates the MBB function, if a braking signal is detected, indicating that the driver has a braking demand, the chassis controller can call the vehicle's auxiliary braking system to intervene in braking based on a backup braking plan corresponding to at least one of the vehicle's braking force demand, braking system failure condition, braking scenario, vehicle speed, driving mode, vehicle load, road conditions, and obstacle position to meet the vehicle's braking demand.

[0056] For example, the main braking system is a multi-circuit hydraulic braking system. If the hydraulic circuit of the main braking system fails exceeding a preset fault circuit threshold, an auxiliary braking system with a larger maximum braking force and a faster braking response speed is called to intervene in braking, such as a mechanical braking system, or multiple auxiliary braking systems are called to intervene in braking. If the hydraulic circuit of the main braking system fails not exceeding a preset fault circuit threshold, an auxiliary braking system with a higher energy utilization rate and less brake wear is called to intervene in braking, such as a motor braking system for feedback braking.

[0057] As another example, the vehicle has different backup braking schemes corresponding to different driving modes. For example, the mechanical braking system can be called when the vehicle is in sports mode, and the motor braking system can be called when the vehicle is in economy mode. In addition, the vehicle speed, vehicle load, road conditions and obstacle location may affect the braking distance of the vehicle. Different backup braking schemes correspond to different target braking distances. For example, when the target braking distance is less than a preset distance threshold, an auxiliary braking system is called to intervene in braking. When the target braking distance is greater than or equal to the preset distance threshold, multiple auxiliary braking systems are called to intervene in braking.

[0058] In one embodiment, the vehicle's braking system generally has a redundant design. For example, the main braking system generally has multiple independent braking circuits or subsystems to ensure that in the event of a failure of the main braking system, other backup braking circuits are still available. The vehicle's braking system integrates multiple different types of braking methods, such as at least one of hydraulic braking, pneumatic braking, mechanical braking, motor feedback braking, and electronic braking. When a failure is detected in the vehicle's main braking system, the system can provide different levels of braking support, from light braking to full braking, depending on the severity and urgency of the failure.

[0059] For example, the vehicle's main braking system is an electronic braking system, the backup braking circuit of the main braking system is a hydraulic braking circuit, and the auxiliary braking system includes a pneumatic braking system and a mechanical braking system. When the electronic braking system fails, if the driver lightly steps on the brakes, it means that the vehicle does not need emergency braking to stop, and the backup hydraulic braking circuit can be used for braking. At the same time, the pneumatic braking system in the auxiliary braking system is used for compensatory braking first. If the driver steps on the brakes heavily, it means that the vehicle does not need emergency braking to stop. At the same time, the backup hydraulic braking circuit is used for braking, and the pneumatic braking system and mechanical braking system in the auxiliary braking system are called for compensatory braking to apply greater braking force to the vehicle to meet the current braking force requirement.

[0060] By distributing the vehicle's current braking force demand to the backup braking circuit in the vehicle's main braking system and the auxiliary braking system, the auxiliary braking system can compensate for the braking force loss caused by the failure of the main braking system. Even if the main braking system fails, the driver can still generate the same or similar braking force as when the main braking system is not faulty by controlling the brake pedal. This ensures the vehicle's driving maneuverability while improving the vehicle's driving safety. At the same time, when the auxiliary braking system is used to brake the vehicle, the vehicle's ABS (Anti-lock Braking System) will detect the vehicle status in real time, so that the braking force generated by the auxiliary braking system can be adjusted according to the vehicle status to prevent the wheels from locking.

[0061] Through the above method, in the event of a failure in the main braking system of the vehicle, the vehicle can be subjected to anti-lock braking control through the auxiliary braking system according to the current braking force demand of the vehicle. For example, different degrees of braking force can be applied to the vehicle through the auxiliary braking system according to the braking force demand, thereby avoiding locking of the vehicle wheels and improving the safety and stability of the vehicle.

[0062] Optionally, the anti-lock graded braking control of the vehicle by the auxiliary braking system includes:

[0063] The actual slip rate of the vehicle during braking is obtained.

[0064] In one implementation, the actual tire speed and tire circumferential speed of the vehicle may be acquired through the ABS, and then the actual slip rate may be determined according to the difference ratio between the actual tire speed and the tire circumferential speed.

[0065] The braking force output by the auxiliary braking system is adjusted according to the actual slip ratio and the preset slip ratio.

[0066] In one embodiment, the vehicle's main braking system fails, the auxiliary braking system intervenes and outputs a braking force of 10N (Newton). The ABS monitors the actual slip rate of the vehicle during braking in real time. If the actual slip rate is greater than the preset slip rate, the braking force output by the auxiliary braking system is reduced to 9N, and the above process is repeated until the actual slip rate is less than the preset slip rate.

[0067] The slip ratio is used to characterize the relative slip degree between the tire and the road surface, and the preset slip ratio corresponds to at least one of the tire friction coefficient, the ground friction coefficient, the vehicle speed and the driving mode.

[0068] Adjusting the braking force output by the auxiliary system according to the vehicle's slip rate during braking can avoid wheel locking, improve braking control accuracy, and thus improve vehicle stability and safety.

[0069] Optionally, adjusting the braking force output by a target auxiliary braking system in a plurality of the auxiliary braking systems according to the actual slip rate and the preset slip rate includes:

[0070] When the actual slip ratio is greater than the preset slip ratio, the braking force output by the auxiliary braking system is reduced until the actual slip ratio of the vehicle is less than or equal to the preset slip ratio.

[0071] In one embodiment, when the auxiliary braking system of the vehicle intervenes in braking, the ABS monitors the actual slip rate S1 of the vehicle during the braking process in real time. When the preset slip rate S0 is greater than the actual slip rate S1, the ABS does not perform anti-lock control on the auxiliary braking system, that is, does not adjust the braking force allocated to the auxiliary braking system, and the vehicle continues to maintain the current deceleration. When the preset slip rate S0 is less than or equal to the actual slip rate S1, the braking force output by the auxiliary braking system is reduced according to a preset coefficient k until the preset slip rate S0 is greater than the actual slip rate S1, wherein the preset coefficient k is the ratio of the braking force T2 output by the target auxiliary system at this moment to the braking force T1 output at the previous moment, that is, T2=k*T1.

[0072] It is worth noting that different auxiliary braking systems have different preset coefficients k. If there are multiple auxiliary braking systems involved in the braking control, when performing anti-lock control on the auxiliary braking systems, the braking force of each involved auxiliary braking system can be adjusted separately, or the total braking force allocated to all auxiliary braking systems can be adjusted, and then the adjusted braking force can be redistributed to these auxiliary braking systems.

[0073] By controlling the braking force of the auxiliary braking system of the vehicle during braking by the above method, it is possible to achieve the best braking effect while preventing the wheels of the vehicle from locking, thereby increasing the stability and safety of the vehicle.

[0074] Optionally, the auxiliary brake system includes a motor brake system and / or a parking brake system.

[0075] Optionally, there are multiple auxiliary braking systems, and the above step S102 includes the following steps.

[0076] Step 1: Determine the braking force requirement of the vehicle.

[0077] Among them, the brake signal can be generated by the driver stepping on the brake pedal, or it can be generated by the vehicle's AEB (Autonomous Emergency Braking) when emergency avoidance or braking is required. Due to a failure in the vehicle's main braking system, in order to ensure the safety of the vehicle, the brake signal can be used to determine the vehicle's braking force requirements to achieve accurate control of the vehicle's braking.

[0078] In one embodiment, the braking signal is an electrical signal generated by a brake pedal. After receiving the electrical signal, the ECU determines the vehicle's braking force requirement based on parameters such as the brake pedal's displacement, opening, vehicle speed, vehicle load, and road conditions, where the vehicle's braking force requirement is the torque for controlling the vehicle's braking.

[0079] In another embodiment, the braking force requirement of the vehicle corresponding to the current braking signal may be determined according to the corresponding relationship between the opening of the brake pedal and the preset braking torque.

[0080] Step 2: Distribute braking force to at least one of the auxiliary braking systems according to braking force requirements, so as to control the auxiliary braking system to output corresponding braking force to brake the vehicle.

[0081] In one embodiment, the braking force demand is used to characterize the driver's braking intention, wherein the braking force demand at least includes the braking force corresponding to the brake pedal depth. Among the multiple auxiliary braking systems of the vehicle, the maximum braking force, braking response speed and braking method that each auxiliary braking system can provide are different. Therefore, one or more auxiliary braking systems can be called for braking according to the braking force corresponding to the current brake pedal depth to match the driver's braking intention. For example, when the braking force corresponding to the current brake pedal depth is small, the auxiliary braking system that causes the least damage to the vehicle's braking system is called for braking. When the braking force corresponding to the current brake pedal depth is large, the auxiliary braking system with a larger maximum braking force is called for braking. In addition, the braking force demand also includes other braking information, such as the displacement speed of the brake pedal. When the displacement speed of the brake pedal exceeds a preset displacement speed threshold, it means that the driver's braking intention is emergency braking, and the auxiliary braking system with a fast response speed and a larger maximum braking force can be preferentially called for braking.

[0082] Optionally, allocating braking force to at least one of the auxiliary braking systems according to the braking force requirement comprises:

[0083] In the event that the failure of the main brake system is a partial failure, the braking force demand is distributed to the non-failed part of the main brake system and to at least one of the auxiliary brake systems.

[0084] In one embodiment, the chassis controller obtains the status of the main braking system in real time. When a failure occurs in the main braking system, it determines whether a redundant backup circuit or a mechanical circuit in the main braking system is faulty. If the backup circuit or the mechanical circuit is not faulty, it is determined that the failure of the main braking system is a partial failure, and braking is performed through the non-faulty part of the main braking system. In addition, the chassis controller calls at least one auxiliary braking system to intervene in braking according to the braking force demand corresponding to the current braking signal, so as to improve braking efficiency and vehicle stability.

[0085] The braking force requirement is equal to the sum of the braking force generated by the main braking system and the braking force generated by the auxiliary braking system.

[0086] Optionally, the distributing the braking force demand to the non-faulty parts of the primary braking system and at least one of the auxiliary braking systems comprises:

[0087] A target auxiliary braking system for providing braking force is selected from the plurality of auxiliary braking systems in sequence according to preset priorities, so that the braking force that can be provided by the non-faulty part of the main braking system and the target auxiliary braking system meets the braking force requirement of the vehicle.

[0088] In one embodiment, the preset priority is used to characterize the order in which different auxiliary braking systems are called when the driver does not intervene in the auxiliary braking control. The auxiliary braking systems are called in order from top to bottom according to the preset priority to cope with different braking situations. After calling the auxiliary braking system of the previous priority, if the braking force generated by the vehicle does not meet the braking force requirement or the deceleration of the vehicle does not meet the deceleration requirement, the auxiliary braking system of the next level is called again, and the braking force requirement is redistributed until the braking force requirement of the vehicle is met.

[0089] Optionally, the plurality of auxiliary brake systems include a parking brake system.

[0090] In one embodiment, the parking brake system is an EPB (Electronic Parking Brake), which can perform active braking in response to the driver pressing a parking button of the vehicle or pulling up a handbrake. The EPB can also automatically brake the vehicle when the vehicle is parked.

[0091] In a case where the braking force demand includes a first braking force demand generated by the driver operating the parking brake system, the calling priority of the parking brake system is higher than that of other auxiliary brake systems among the plurality of auxiliary brake systems.

[0092] It is worth mentioning that when the driver presses the vehicle's parking button or pulls the handbrake for active braking, the parking brake system is used for braking first, so that the vehicle follows the driver's operation, improving the vehicle's driving controllability.

[0093] Optionally, the plurality of auxiliary brake systems comprises an electric motor brake system.

[0094] In one embodiment, the motor braking system is a VCU (Vehicle Control Unit), which brakes by energy recovery, that is, converts the mechanical energy of the motor during braking into electrical energy and feeds it back to the power grid or other loads.

[0095] When the braking force demand is the second braking force demand generated by the driver operating the brake pedal, the calling priority of the motor brake system in the preset priority is higher than that of other auxiliary brake systems among the plurality of auxiliary brake systems.

[0096] It is worth noting that when the driver does not intervene in the control of auxiliary braking, the motor braking system is used for feedback braking first to improve energy utilization and reduce mechanical wear of the vehicle.

[0097] For example, when the driver does not intervene in the control of auxiliary braking, the motor braking system has a higher priority than the parking brake system. Compared with the parking brake system, the motor braking system can convert the vehicle's kinetic energy into electrical energy for storage during braking, and has a higher energy utilization rate. The motor braking system's braking force control is more accurate, which helps to maintain the vehicle's stability and driving comfort during braking. In addition, it can also reduce the mechanical wear of the braking system and extend the service life of the braking system. If the braking force generated by the vehicle does not meet the braking force requirements after auxiliary braking control is performed through the motor braking system, the parking brake system is called again.

[0098] Another example, when the driver intervenes to control the auxiliary braking, such as the driver pulls up the handbrake or presses the brake button, it means that the driver needs to stop the vehicle urgently. Since the parking brake system can provide greater braking force than the motor brake system, in order to quickly respond to the emergency braking needs corresponding to the driver's operation, the parking brake system has a higher priority than the motor brake system, that is, the parking brake system is called first for braking control. If the braking force generated by the vehicle does not meet the braking force requirement after the parking brake system performs auxiliary braking control, the motor brake system is called again. This can ensure that the driver's operation is responded to quickly and effectively, optimize the driving experience, and improve the safety of the vehicle.

[0099] Optionally, the main brake system is a hydraulic brake system, and the main brake system includes multiple hydraulic circuits and mechanical circuits.

[0100] In the case that all the hydraulic circuits of the main brake system fail, the remaining part of the main brake system is the mechanical circuit in the main brake system.

[0101] In the event of a failure in the braking portions of the multiple hydraulic circuits of the main brake system, the non-failed portion of the main brake system is braked by the mechanical circuit and / or the non-failed hydraulic circuit in the main brake system.

[0102] In one embodiment, see Figure 2 As shown, the main braking system is IPB, and the auxiliary braking system includes EPB system and VCU. The following steps can be used to control the braking of a vehicle with a main braking system failure.

[0103] S301, determining whether a braking signal is received.

[0104] If a braking signal is received, S302 is executed; if no braking signal is received, S301 is repeatedly executed.

[0105] S302: Determine whether the VCU meets the activation condition.

[0106] In one embodiment, the VCU does not meet the activation condition in any of the following situations.

[0107] Case 1: The VCU fails, for example, the core component MCU (Microcontroller Unit) of the VCU fails.

[0108] Case 2: The SOC (State of Charge) of the vehicle battery does not meet the conditions for power regeneration. For example, the SOC of the vehicle battery is fully charged, and energy regeneration cannot be performed to ensure battery safety.

[0109] Case 3: The vehicle is in reverse gear, where the vehicle dynamics are different from forward gear and energy recovery is not required or appropriate. VCU deactivation helps avoid unnecessary braking effects during reverse maneuvers, thereby improving handling and safety.

[0110] Case 4: The vehicle is in N gear (neutral), where N gear is usually used for vehicle pause or coasting. At this time, the vehicle is not in a driving state. The inactivation of the VCU can prevent erroneous intervention in motor control when power output is not required, ensuring the naturalness of the vehicle's coasting and the driving intention.

[0111] If the VCU meets the activation condition, step S303 is executed; if the VCU does not meet the activation condition, step S304 is executed.

[0112] S303, braking is performed through the non-faulty circuit of the IPB system and the VCU.

[0113] In one embodiment, if part of the hydraulic circuit of the IPB system fails, the non-failed hydraulic circuit and backup mechanical circuit of the IPB and the VCU can be called to perform auxiliary braking.

[0114] Further execute S305.

[0115] S304: Determine whether the EPB system meets activation conditions.

[0116] In one implementation, the activation condition of the EPB system is that the EPB system has no faults.

[0117] S305: Determine whether the braking force output by the vehicle meets the braking force requirement.

[0118] When braking is performed through the non-faulty circuit of the IPB system and the VCU, if the braking force output by the vehicle cannot meet the braking force requirement, S307 is executed; if the braking force output by the vehicle meets the braking force requirement, S306 is executed.

[0119] S306 , braking the vehicle with the braking torque currently allocated to the non-faulty circuit of the IPB and the VCU.

[0120] If the braking force output by the vehicle is sufficient to meet the braking force requirement or the EPB system does not meet the activation conditions, the braking torque currently allocated to the VCU and IPB is maintained to control the vehicle braking.

[0121] Further execute S310.

[0122] S307: Determine whether the EPB system meets the activation condition.

[0123] If the braking force output by the vehicle is insufficient to meet the braking force requirement, the EPB system needs to be called up to intervene in the braking control, that is, the IPB system, EPB system and VCU are used to brake the vehicle at the same time. Before calling the EPB system, it is necessary to determine whether the EPB meets the activation conditions, that is, determine whether the EPB system has a fault.

[0124] If the EPB system meets the activation condition, S308 is executed. If the EPB system does not meet the activation condition, the process returns to S306.

[0125] S308, distributing the braking force demand to the non-faulty circuits of the IPB system, the VCU, and the EPB system.

[0126] In one embodiment, the braking force demand is preferentially distributed to the non-faulty circuits of the IPB and the VCU, and the difference between the maximum braking force that the IPB and VCU can currently generate and the braking force demand is distributed to the EPB to maximize the vehicle's energy recovery and reduce mechanical wear.

[0127] Further execute S309.

[0128] S309, determining whether a manual control signal of the EPB system is detected.

[0129] The manual control signal is an operation signal of the driver manually controlling the EPB system, such as pulling the handbrake, pressing the brake button, and pressing the parking button.

[0130] If the manual control signal of the EPB system is received, S311 is executed; if the manual control signal of the EPB system is not received, S310 is executed.

[0131] S310, determining whether the actual slip ratio S1 is not lower than the preset slip ratio S0.

[0132] In one implementation, the vehicle's slip rate is detected in real time by a chassis controller. If S1 ≥ S0, S312 is executed; if S1 < S0, S315 is executed.

[0133] S311, adjusting the priority of the EPB system to be higher than the VCU, and reallocating the braking force demand.

[0134] In one embodiment, if the driver manually intervenes in the control of the EPB system, the braking force demand is redistributed to the non-faulty circuits of the IPB system and the EPB system. If braking with the non-faulty circuits of the IPB system and the EPB system cannot meet the braking force demand of the vehicle, it is determined whether the VCU meets the activation conditions. If the VCU meets the activation conditions, the braking force demand of the vehicle is redistributed to the IPB system, the EPB system and the VCU. If the VCU does not meet the activation conditions, the current distribution method of the braking force demand is maintained and braking continues.

[0135] Further execute S310.

[0136] S312, each auxiliary braking system performs anti-lock control.

[0137] For example, if the actual slip ratio S1 of the vehicle is greater than the preset slip ratio S0 when the EPB system performs auxiliary braking, the braking force of the EPB system is reduced according to a preset reduction rate or a preset reduction ratio until the actual slip ratio S1 of the vehicle is less than the preset slip ratio S0.

[0138] S313, distributing the braking force demand to the non-faulty circuits of the IPB system and the EPB system.

[0139] When the EPB does not meet the activation condition, braking is performed through the IPB and the VCU, and S309 is further executed.

[0140] S314, braking is performed through the non-faulty circuit of the IPB system.

[0141] In the case that each auxiliary braking system does not meet the activation condition, braking is performed through the non-faulty circuit of the IPB, and S315 is further executed.

[0142] S315: Braking the vehicle with the torque currently allocated to each braking system.

[0143] Through the above method, different braking control schemes are executed according to the failure conditions of the vehicle's braking system, and the vehicle's auxiliary braking system can be controlled to output braking forces of different torques according to different braking force requirements of the vehicle, thereby improving the driving stability of the vehicle. The vehicle's slip rate during braking is monitored and anti-lock control is performed in a timely manner, thereby improving the safety of the vehicle.

[0144] Optionally, Figure 3 is a flow chart of a vehicle braking control method according to an exemplary embodiment. Figure 3 As shown, the method includes the following steps.

[0145] S401. Determine whether a main brake system of the vehicle fails.

[0146] In one implementation, while the vehicle is traveling, the chassis controller monitors the fault status of the main brake system of the vehicle in real time. When the main brake system fails, the MBB function of the chassis controller is activated and step S402 is executed.

[0147] S402: Acquire the accelerator pedal information of the vehicle.

[0148] In one embodiment, if a primary braking system of the vehicle fails, the chassis controller first monitors the accelerator pedal signal to determine the driver's input status and whether intervention of the auxiliary braking system is required.

[0149] S403: Determine, based on the accelerator pedal information, whether the effective opening of the accelerator pedal is greater than a preset opening threshold.

[0150] In one embodiment, when the accelerator pedal information is not detected or the accelerator pedal information indicates that the effective opening of the accelerator pedal is less than or equal to the preset opening threshold, it indicates that the driver has no intention to accelerate, and the auxiliary brake system can be controlled to intervene in the brake control, and S404 is executed. When the accelerator pedal signal indicates that the effective opening of the accelerator pedal is greater than the preset opening threshold, it indicates that the driver has the intention to accelerate, the auxiliary brake system is not controlled to intervene in the brake control, and the process returns to step S401.

[0151] Among them, the effective opening of the accelerator pedal is less than the preset opening threshold value, which may be due to the driver not controlling the accelerator pedal or the accelerator pedal failure. The accelerator pedal failure may cause the driver to press the accelerator pedal but no accelerator pedal signal is generated. In this case, the effective opening of the accelerator pedal is equal to zero.

[0152] In one embodiment, the preset opening threshold may be set to 2%.

[0153] S404: Determine whether the system status of the auxiliary braking system of the vehicle is abnormal.

[0154] If there is an exception, execute S407; if there is no exception, execute S405.

[0155] S405: Control the auxiliary brake system to enter a pre-clamping mode.

[0156] Among them, the pre-clamping mode is used to adjust the state of the brake of the auxiliary braking system to improve the braking response speed of the vehicle.

[0157] In one embodiment, the auxiliary brake system is an EPB system. When the pre-clamping function is activated, the chassis controller sends a pre-clamping signal to the brake of the EPB system, so that the brake is slightly clamped, that is, the brake is adjusted from the initial position when the brake has not been braked to a preset position that is about to contact the brake disc of the wheel, so as to reduce the idle travel during the brake activation process. In the pre-clamping mode, the brake of the EPB system is slightly in contact with or not in contact with the brake disc of the wheel, so that the braking force generated is very small or no braking force is generated, and the normal driving of the vehicle is not affected. The response time from the brake pedal being pressed to the full application of the braking force is reduced without affecting the driving intention of the driver, and the safety of the vehicle is improved in the event of emergency braking or failure of the main brake system of the vehicle.

[0158] In another embodiment, the auxiliary brake system is a hydraulic brake system. When the pre-clamping function is activated, the chassis controller controls the brake cylinder of the hydraulic brake system to perform hydraulic pressure charging, thereby reducing the time for the brake cylinder to respond to the brake signal.

[0159] S406: Determine whether the current vehicle state satisfies the activation condition of the auxiliary braking system.

[0160] In one embodiment, after the auxiliary braking system of the vehicle enters the pre-clamping mode, the vehicle gear position and / or the accelerator pedal opening can be acquired through the chassis controller to determine the current driving state of the vehicle.

[0161] If the vehicle gear is in the driving gear and the opening of the accelerator pedal is greater than or equal to the preset opening threshold, it means that the vehicle is in a high-speed driving state, the driver's driving intention is to accelerate, it is not suitable for the auxiliary braking system to intervene, and the activation conditions of the auxiliary braking system are not met, then the pre-clamping mode is exited and return to step S401.

[0162] If the vehicle is not in a driving gear, for example, in a parking gear or neutral gear, or the accelerator pedal opening is less than a preset opening threshold, it means that the vehicle is in a low-speed driving state, and the driver's driving intention is not to accelerate. The auxiliary braking system can intervene in the vehicle's braking control. If the activation conditions of the auxiliary braking system are met, step S407 is executed.

[0163] S407: Determine whether a braking signal is detected.

[0164] In one embodiment, if the vehicle is not in a driving gear or the accelerator pedal opening is lower than a preset opening threshold, the chassis controller detects a brake signal, such as a brake light or a brake pedal status, to provide emergency braking support when necessary.

[0165] If a braking signal is detected, the above step S102 is executed; if no braking signal is detected, the process returns to step S401.

[0166] Through the above method, when the main braking system of the vehicle fails, the chassis controller can quickly respond to the braking control and avoid unnecessary auxiliary braking control, thereby reducing interference with the driver's driving experience and improving the vehicle's handling and safety.

[0167] Optionally, the method further comprises:

[0168] When there is no abnormality in the vehicle's main braking control system, or the vehicle is in driving state and the accelerator pedal depth is greater than or equal to the preset opening threshold, or no braking signal is detected and the vehicle speed is less than the preset vehicle speed threshold, stop braking the vehicle through the vehicle's auxiliary control system.

[0169] In one implementation, the chassis controller will not use the auxiliary braking system to intervene in the vehicle's braking control under the following circumstances.

[0170] Situation 1: When the vehicle's main braking system works normally, that is, when there is no abnormality in the main braking control system, the auxiliary braking system will not be started or shut down, and the vehicle's main braking system will be relied upon for braking to avoid unnecessary intervention of the auxiliary braking system and reduce safety hazards caused by system misjudgment.

[0171] Case 2: When the vehicle's main braking system fails, the vehicle is in driving state and the accelerator pedal depth is greater than or equal to the preset opening threshold. This situation indicates that the driver may be trying to continue driving instead of braking. If the chassis controller cannot detect the braking signal, the auxiliary braking system will not be started or will be turned off to ensure normal acceleration of the vehicle and avoid affecting driving performance due to incorrect start-up of the auxiliary braking system.

[0172] Case 3: When the vehicle's main braking system fails, the braking signal changes from being present to being absent and the vehicle's speed is lower than the preset speed threshold. This indicates that the driver has stopped stepping on the brake pedal and the vehicle has decelerated to a sufficiently safe speed and no longer requires additional braking force. Therefore, the auxiliary braking system stops intervening in the vehicle's braking control, allowing the driver to freely control the vehicle speed according to actual road conditions, thereby improving driving comfort and flexibility.

[0173] Through the above method, the vehicle status and driver's intention are intelligently judged, and the auxiliary braking system intervenes only when necessary, achieving more intelligent and precise braking control.

[0174] See also Figure 4 As shown, the present disclosure further provides a braking control device 200 for a vehicle. The braking system of the vehicle includes a main braking system and an auxiliary braking system. The braking control device 200 includes a determination module 201 and a control module 202 .

[0175] The determination module 201 is configured to determine whether the main brake system fails.

[0176] The control module 202 is configured to perform anti-lock graded braking control on the vehicle through the auxiliary braking system when a braking signal is detected.

[0177] Optionally, the control module 202 is configured to:

[0178] The actual slip rate of the vehicle during braking is obtained.

[0179] The braking force output by the auxiliary braking system is adjusted according to the actual slip ratio and the preset slip ratio.

[0180] Optionally, the control module 202 is configured to:

[0181] When the actual slip ratio is greater than the preset slip ratio, the braking force output by the auxiliary braking system is reduced until the actual slip ratio of the vehicle is less than or equal to the preset slip ratio.

[0182] Optionally, there are multiple auxiliary braking systems, and the control module 202 is configured to:

[0183] A braking force requirement of the vehicle is determined.

[0184] The braking force is distributed to at least one of the auxiliary braking systems according to the braking force requirement, so as to control the auxiliary braking system to output the corresponding braking force to perform graded braking on the vehicle.

[0185] Optionally, the control module 202 is configured to:

[0186] In the event that the failure of the main brake system is a partial failure, the braking force demand is distributed to the non-failed part of the main brake system and to at least one of the auxiliary brake systems.

[0187] Optionally, the control module 202 is configured to:

[0188] A target auxiliary braking system for providing braking force is selected from the plurality of auxiliary braking systems in sequence according to preset priorities, so that the braking force that can be provided by the non-faulty part of the main braking system and the target auxiliary braking system meets the braking force requirement of the vehicle.

[0189] Optionally, the multiple auxiliary braking systems include a parking brake system. When the braking force requirement includes a first braking force requirement triggered by the driver operating the parking brake system, the calling priority of the parking brake system in the preset priority level is higher than that of other auxiliary braking systems in the multiple auxiliary braking systems.

[0190] Optionally, the multiple auxiliary braking systems include a motor braking system, and when the braking force requirement is a second braking force requirement triggered by the driver operating the brake pedal, the calling priority of the motor braking system in the preset priority level is higher than other auxiliary braking systems in the multiple auxiliary braking systems.

[0191] Optionally, the main brake system is a hydraulic brake system, and the main brake system includes multiple hydraulic circuits and mechanical circuits.

[0192] In the case that the multiple hydraulic circuits of the main brake system all fail, the non-failed portion of the main brake system is the mechanical circuit in the main brake system.

[0193] In the event that the plurality of hydraulic circuit braking portions of the main brake system fail, the non-failed portion of the main brake system is the mechanical circuit and / or the non-failed hydraulic circuit brake in the main brake system.

[0194] Optionally, the control module 202 is configured to:

[0195] In case a main brake system of the vehicle fails, an accelerator pedal state of the vehicle is obtained.

[0196] When the accelerator pedal state indicates that the effective opening of the accelerator pedal does not exceed a preset opening threshold, a system state of the auxiliary braking system of the vehicle is determined.

[0197] When the system state of the auxiliary braking system of the vehicle is characterized as normal, the auxiliary braking system is controlled to enter a pre-clamping mode, and the pre-clamping mode is used to adjust the state of the brake of the auxiliary braking system to improve the braking response speed of the vehicle.

[0198] Optionally, the control module 202 is configured to:

[0199] When the auxiliary brake system of the vehicle is in the pre-clamping mode, a gear state and an accelerator pedal state of the vehicle are acquired.

[0200] When the gear state of the vehicle is a driving gear and the accelerator pedal state indicates that the effective opening of the accelerator pedal is greater than or equal to the preset opening threshold, the auxiliary braking system is controlled to exit the pre-clamping mode.

[0201] When the gear state of the vehicle is a non-driving gear, or the accelerator pedal state indicates that the opening of the accelerator pedal is less than the preset opening threshold, the brake signal is continuously detected.

[0202] Optionally, the control module 202 is configured to:

[0203] When there is no abnormality in the main braking control system of the vehicle, or the vehicle is in a driving state and the accelerator pedal depth is greater than or equal to a preset opening threshold, or the braking signal is not detected and the vehicle speed is less than a preset vehicle speed threshold, stop braking control of the vehicle through the vehicle's auxiliary control system.

[0204] Regarding the device in the above embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment of the method, and will not be elaborated here.

[0205] The present disclosure also provides a computer-readable storage medium having a computer program stored thereon, and the computer program implements the method provided by the present disclosure when executed by a processor.

[0206] The present disclosure also provides a vehicle braking control device, comprising:

[0207] a memory having a computer program stored thereon;

[0208] The processor is used to execute the computer program in the memory to implement the method provided by the present disclosure.

[0209] The present disclosure also provides a vehicle, including a processor and a brake control device of the vehicle provided by the present disclosure.

[0210] Figure 5 6 is a block diagram of a vehicle 600 according to an exemplary embodiment. For example, the vehicle 600 may be a hybrid vehicle, a non-hybrid vehicle, an electric vehicle, a fuel cell vehicle, or other types of vehicles. The vehicle 600 may be an autonomous vehicle, a semi-autonomous vehicle, or a non-autonomous vehicle.

[0211] Reference Figure 5 , the vehicle 600 may include various subsystems, for example, an infotainment system 610, a perception system 620, a decision control system 630, a drive system 640, and a computing platform 650. The vehicle 600 may also include more or fewer subsystems, and each subsystem may include multiple components. In addition, each subsystem and each component of the vehicle 600 may be interconnected by wire or wireless means.

[0212] In some embodiments, the infotainment system 610 may include a communication system, an entertainment system, and a navigation system, among others.

[0213] The perception system 620 may include several sensors for sensing information about the environment around the vehicle 600. For example, the perception system 620 may include a global positioning system (the global positioning system may be a GPS system, or a Beidou system or other positioning systems), an inertial measurement unit (IMU), a laser radar, a millimeter wave radar, an ultrasonic radar, and a camera.

[0214] The decision control system 630 may include a computing system, a vehicle controller, a steering system, a throttle, and a braking system.

[0215] The drive system 640 may include components that provide powered motion for the vehicle 600. In one embodiment, the drive system 640 may include an engine, an energy source, a transmission system, and wheels. The engine may be one or a combination of an internal combustion engine, an electric motor, and an air compression engine. The engine is capable of converting energy provided by the energy source into mechanical energy.

[0216] Some or all functions of the vehicle 600 are controlled by a computing platform 650. The computing platform 650 may include at least one processor 651 and a memory 652, and the processor 651 may execute instructions 653 stored in the memory 652.

[0217] The processor 651 may be any conventional processor, such as a commercially available CPU. The processor may also include a graphics processor (Graphic Process Unit, GPU), a field programmable gate array (Field Programmable Gate Array, FPGA), a system on chip (System on Chip, SOC), an application specific integrated circuit (Application Specific Integrated Circuit, ASIC) or a combination thereof.

[0218] The memory 652 may be implemented by any type of volatile or nonvolatile memory device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic disk or optical disk.

[0219] In addition to the instructions 653 , the memory 652 may also store data, such as road maps, route information, and data such as the location, direction, and speed of the vehicle. The data stored in the memory 652 may be used by the computing platform 650 .

[0220] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings; however, the present disclosure is not limited to the specific details in the above embodiments. Within the technical concept of the present disclosure, a variety of simple modifications can be made to the technical solution of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0221] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings; however, the present disclosure is not limited to the specific details in the above embodiments. Within the technical concept of the present disclosure, a variety of simple modifications can be made to the technical solution of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0222] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

[0223] In addition, various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.

Claims

1. A vehicle braking control method, characterized in that: The braking system of the vehicle includes a main braking system and a plurality of auxiliary braking systems, and the method includes: determining that the main brake system is faulty; In the case of detecting a braking signal, performing anti-lock graded braking control on the vehicle through the plurality of auxiliary braking systems, including: calling the auxiliary braking system of the vehicle to intervene in braking according to a backup braking scheme corresponding to at least one of the braking force requirement of the vehicle, the fault condition of the main braking system, the braking scenario, the vehicle speed, the driving mode, the vehicle load, the road condition, and the obstacle position; The step-by-step anti-lock braking control of the vehicle is performed by the auxiliary braking system, including: determining a braking force requirement of the vehicle; In the case where the failure of the main brake system is a partial failure, a target auxiliary brake system for providing braking force is selected from the plurality of auxiliary brake systems in sequence according to a preset priority, so that the braking force that can be provided by the non-failed part of the main brake system and the target auxiliary brake system meets the braking force requirement of the vehicle; Wherein, the main braking system is a multi-circuit hydraulic braking system, the plurality of auxiliary braking systems include a mechanical braking system, a parking braking system and a motor braking system, and when the braking force requirement includes a first braking force requirement triggered by the driver operating the parking braking system, the parking braking system has a higher calling priority in the preset priority than other auxiliary braking systems in the plurality of auxiliary braking systems, and when the braking force requirement is a second braking force requirement triggered by the driver operating the brake pedal, the motor braking system has a higher calling priority in the preset priority than other auxiliary braking systems in the plurality of auxiliary braking systems; and In the case where the fault of the main braking system is the partial fault, if the fault circuit of the main braking system exceeds the preset fault circuit threshold, the calling priority of the mechanical braking system in the preset priority is higher than that of other auxiliary braking systems among the multiple auxiliary braking systems; if the fault circuit of the main braking system does not exceed the preset fault circuit threshold, the calling priority of the motor braking system in the preset priority is higher than that of other auxiliary braking systems among the multiple auxiliary braking systems.

2. The braking control method according to claim 1, characterized in that: The step-by-step anti-lock braking control of the vehicle is performed by the auxiliary braking system, including: Obtaining an actual slip rate of the vehicle during braking; The braking force output by the auxiliary braking system is adjusted according to the actual slip ratio and the preset slip ratio.

3. The braking control method according to claim 2, characterized in that: The step of adjusting the braking force output by the auxiliary braking system according to the actual slip rate and the preset slip rate includes: When the actual slip ratio is greater than the preset slip ratio, the braking force output by the auxiliary braking system is reduced until the actual slip ratio of the vehicle is less than or equal to the preset slip ratio.

4. The braking control method according to claim 1, characterized in that: The main brake system is a hydraulic brake system, and the main brake system includes a plurality of hydraulic circuits and a mechanical circuit; In the case that the multiple hydraulic circuits of the main brake system all fail, the non-failed part of the main brake system is the mechanical circuit in the main brake system; In the event that the plurality of hydraulic circuit braking portions of the main brake system fail, the non-failed portion of the main brake system is the mechanical circuit and / or the non-failed hydraulic circuit brake in the main brake system.

5. The braking control method according to claim 1, characterized in that: Before determining the braking force requirement of the vehicle when a braking signal is detected, the method further includes: In case a main brake system of the vehicle fails, obtaining a state of an accelerator pedal of the vehicle; When the accelerator pedal state indicates that the effective opening of the accelerator pedal does not exceed a preset opening threshold, determining a system state of the auxiliary braking system of the vehicle; When the system state of the auxiliary braking system of the vehicle is characterized as normal, the auxiliary braking system is controlled to enter a pre-clamping mode, and the pre-clamping mode is used to adjust the state of the brake of the auxiliary braking system to improve the braking response speed of the vehicle.

6. The braking control method according to claim 5, characterized in that: The method further comprises: When the auxiliary brake system of the vehicle is in the pre-clamping mode, obtaining a gear state and an accelerator pedal state of the vehicle; When the gear state of the vehicle is a driving gear and the accelerator pedal state indicates that the effective opening of the accelerator pedal is greater than or equal to the preset opening threshold, controlling the auxiliary brake system to exit the pre-clamping mode; When the gear state of the vehicle is a non-driving gear, or the accelerator pedal state indicates that the opening of the accelerator pedal is less than the preset opening threshold, the brake signal is continuously detected.

7. The braking control method according to any one of claims 1 to 6, characterized in that: The method further comprises: When there is no abnormality in the main braking control system of the vehicle, or the vehicle is in a driving state and the accelerator pedal depth is greater than or equal to a preset opening threshold, or the braking signal is not detected and the vehicle speed is less than a preset vehicle speed threshold, stop braking control of the vehicle through the vehicle's auxiliary control system.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

9. A vehicle braking control device, characterized in that: include: a memory having a computer program stored thereon; A processor, configured to execute the computer program in the memory to implement the method according to any one of claims 1 to 7.

10. A vehicle, characterized in that: A vehicle brake control device comprising a processor and the vehicle brake control device according to claim 9.

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