Active adjustment system, method and computer program product for emb disc gap

Abstract

The application relates to the field of automobile braking technology, in particular to an EMB disc gap active adjustment system, method and computer program product. The system comprises an emergency braking risk factor calculation module, a disc gap adjustment module and a computer program product. The emergency braking risk factor calculation module obtains a first risk coefficient according to a basic driving risk value, a passenger flow correction coefficient and a vehicle flow correction coefficient, sets a second risk coefficient according to an AEB trigger time, and obtains an emergency braking risk factor according to the first risk coefficient and the second risk coefficient. When the emergency braking risk factor is less than or equal to a first threshold value, the disc gap adjustment module sets a disc gap target value as a maximum allowed disc gap; when the emergency braking risk factor is greater than the first threshold value, the disc gap adjustment module sets the disc gap target value according to a negative correlation relationship between the emergency braking risk factor and the disc gap target value. The application realizes dynamic switching of extreme energy consumption optimization in a low-risk scene and extreme safety guarantee in a high-risk scene.

Description

Technical Field

[0001] This invention relates to the field of automotive braking technology, specifically to an active adjustment system, method, and computer program product for EMB disc clearance. Background Technology

[0002] With the rapid iteration of new energy vehicles and advanced intelligent driving technologies, electromechanical braking systems (EMB) have become the core development direction of intelligent electric vehicle braking systems due to their core advantages of fast response speed, high control precision, and compatibility with drive-by-wire chassis architecture.

[0003] There is an inherent contradiction between the braking safety performance of the EMB system and the energy consumption performance of the vehicle: in order to reduce wheel-side drag torque and improve the driving range of pure electric vehicles, the brake disc clearance needs to be increased; however, increasing the disc clearance will prolong the braking free travel, weaken the braking response speed, and directly affect the braking safety redundancy of advanced driver assistance systems, especially in AEB emergency braking scenarios.

[0004] Existing technologies mostly rely on brake pre-filling after AEB function activation to adjust the gap, but cannot achieve active pre-adjustment of disc gap based on real-time road environment and collision risk level. This makes it difficult to achieve dynamic balance between low drag energy consumption optimization and driving safety assurance in all scenarios, which restricts the improvement of the overall performance of EMB system and its large-scale implementation. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by providing an active adjustment system for EMB platter gap, comprising: The emergency braking risk factor calculation module sets a basic driving risk value based on the driving environment, sets a pedestrian flow correction coefficient based on the total pedestrian and non-motorized vehicle flow density, sets a vehicle flow correction coefficient based on the motor vehicle flow density, obtains a first risk coefficient based on the basic driving risk value, pedestrian flow correction coefficient, and vehicle flow correction coefficient, sets a second risk coefficient based on the AEB trigger time, and obtains the emergency braking risk factor based on the first risk coefficient and the second risk coefficient. The disc clearance adjustment module sets the disc clearance target value to the maximum permissible disc clearance when the emergency braking risk factor is less than or equal to the first threshold. When the emergency braking risk factor is greater than the first threshold, it sets the disc clearance target value according to the principle that the emergency braking risk factor and the disc clearance target value are negatively correlated, and adjusts the disc clearance according to the disc clearance target value.

[0006] Furthermore, in the emergency braking risk factor calculation module, the specific method for setting the basic driving risk value based on the driving environment is as follows: The basic driving risk values ​​are set in ascending order based on the driving environment classification of closed highways, urban expressways, urban non-expressways, and commercial, residential, or school zones.

[0007] Furthermore, in the emergency braking risk factor calculation module, the specific method for setting the pedestrian flow correction coefficient based on the total pedestrian and non-motorized vehicle flow density is as follows: Based on the principle that the total number of pedestrians and non-motorized vehicles within the first preset distance in front of the vehicle is positively correlated with the pedestrian flow correction coefficient, a pedestrian flow correction coefficient is set.

[0008] Furthermore, in the emergency braking risk factor calculation module, the specific method for setting the traffic flow correction coefficient based on the vehicle traffic flow density is as follows: Based on the principle that the number of motor vehicles within the second preset distance in front of the vehicle and the traffic flow correction coefficient are positively correlated, the traffic flow correction coefficient is set.

[0009] Furthermore, in the emergency braking risk factor calculation module, the specific method for obtaining the first risk coefficient based on the basic driving risk value, pedestrian flow correction coefficient, and vehicle flow correction coefficient is as follows: In the formula, As the first risk factor, To be The calculation results are limited to the amplitude-limiting function within the range of [0,1]. Based on basic driving risk values, Human traffic correction factor This is a traffic flow correction factor.

[0010] Furthermore, in the emergency braking risk factor calculation module, the specific method for setting the second risk coefficient based on the AEB trigger time is as follows: Based on the principle that the AEB trigger time and the second risk coefficient are negatively correlated, the second risk coefficient is set.

[0011] Furthermore, in the emergency braking risk factor calculation module, the specific method for obtaining the emergency braking risk factor based on the first risk coefficient and the second risk coefficient is as follows: The maximum value between the first risk coefficient and the second risk coefficient is taken as the emergency braking risk factor; When the first or second risk factor cannot be obtained, the emergency braking risk factor is set to a preset value.

[0012] Furthermore, in the disk gap adjustment module, the specific method for adjusting the disk gap according to the target value is as follows: EMB controls the drive motor via a position loop to retract the brake piston to the corresponding position of the target value of the disc clearance; When the braking system receives a braking request from the vehicle function, it immediately interrupts the current clearance adjustment process and responds to the corresponding braking torque command of the vehicle function's braking request. The control priority of disc gap adjustment is lower than the braking request of the vehicle function, which comes from one of AEB, ABS, ESC, and BBF.

[0013] An active adjustment method for EMB platter gap, comprising: The basic driving risk value is set according to the driving environment, the pedestrian flow correction coefficient is set according to the total flow density of pedestrians and non-motorized vehicles, the vehicle flow correction coefficient is set according to the flow density of motor vehicles, the first risk coefficient is obtained according to the basic driving risk value, the pedestrian flow correction coefficient and the vehicle flow correction coefficient, the second risk coefficient is set according to the AEB trigger time, and the first risk coefficient and the second risk coefficient are merged to obtain the emergency braking risk factor. When the emergency braking risk factor is less than or equal to the first threshold, the disc clearance target value is set as the maximum permissible disc clearance. When the emergency braking risk factor is greater than the first threshold, the disc clearance target value is set according to the principle that the emergency braking risk factor and the disc clearance target value are negatively correlated, and the disc clearance is adjusted according to the disc clearance target value.

[0014] A computer program product includes a computer program / instructions that, when executed by a processor, implement the above-described active adjustment method for EMB platter gap.

[0015] The beneficial effects of this invention are as follows: 1. In view of the lag in existing technologies that can only perform brake pre-filling and gap adjustment after AEB activation, this invention achieves dynamic switching between extreme energy consumption optimization in low-risk scenarios and extreme safety assurance in high-risk scenarios through the joint control of real-time emergency braking risk assessment and active pre-adjustment of disc gap.

[0016] 2. Emergency braking risk is divided into two independent dimensions: inherent environmental risk, reflecting the basic road hazard level, and dynamic collision risk, reflecting the possibility of immediate collision. Inherent environmental risk is calculated by multiplying the basic driving risk value with correction coefficients for pedestrian and vehicle traffic flow, simulating the nonlinear characteristic of a sharp increase in emergency braking probability when multiple high-risk factors coexist. Dynamic collision risk directly reuses the existing AEB trigger time parameters, without the need for new complex algorithms. By taking the maximum value of the first and second risk coefficients as the final emergency braking risk factor, the safety blind spot of single-dimensional risk assessment is solved: it can respond promptly to the immediate collision risk caused by sudden obstacles in low-inherent-risk scenarios (such as closed highways), and maintain a high level of safety alert even in high-inherent-risk scenarios (such as commercial / school areas) when there is no immediate collision risk.

[0017] 3. To address the issue of frequent actuator movements and shortened lifespan caused by continuous linear gap adjustments, this invention employs a segmented fixed disc gap control strategy in the medium-to-high risk range. The risk factor value range is divided into seven consecutive, non-overlapping segments, each corresponding to a unique fixed disc gap target value. A duration threshold is set, and gap adjustment is triggered only when the risk factor crosses the segment boundary and the duration exceeds this threshold. This strategy, while ensuring timely risk response, completely avoids the problem of high-frequency disc gap adjustments caused by minor fluctuations in risk factors, effectively reducing the number of actuator movements in the EMB and significantly extending the lifespan of components such as servo motors and reduction gear transmission assemblies.

[0018] 4. The control priority of disc clearance adjustment is specified to be lower than the braking requests of all vehicle functions (including AEB, ABS, ESC and driver active braking requests). When the braking system receives any braking command, the current clearance adjustment process is immediately interrupted and the braking torque command is unconditionally responded to, thus avoiding braking response delay caused by the conflict between clearance adjustment action and braking request. Attached Figure Description

[0019] Figure 1 This is a block diagram of the active adjustment system for EMB disk gap of the present invention.

[0020] Figure 2 This is a flowchart of the active adjustment method for EMB disk gap according to the present invention.

[0021] Figure 3 A graph showing the relationship between the emergency braking risk factor and the reduction of disc clearance. Detailed Implementation

[0022] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0023] Definitions: Low drag optimization: This refers to a technical approach that reduces the contact friction (i.e., braking drag torque) between the brake pads and brake discs in non-braking states through control strategies or structural design, thereby reducing energy loss during vehicle operation. For pure electric vehicles, every 1 Nm reduction in wheel-side drag torque can increase the vehicle's range by approximately 1% to 2%.

[0024] Closed expressways: According to the "Technical Standards for Highway Engineering" (JTG B01-2014), these are multi-lane highways exclusively for motor vehicle traffic with separate lanes and controlled access. They are fully enclosed, grade-separated, without at-grade intersections, and without pedestrian or non-motorized vehicle traffic. A central median separates the two lanes, and guardrails are installed on both sides. The design speed is typically 80-120 km / h, with continuous and stable traffic flow and no traffic lights or waiting areas.

[0025] Urban expressways: According to the "Code for Design of Urban Road Engineering" (CJJ 37-2012), these are urban roads built within cities, with a central median, fully controlled access, and controlled spacing and form of entrances and exits, allowing for continuous traffic of motor vehicles. They have a semi-enclosed structure, with no traffic lights on the main road, and auxiliary roads that can intersect with other roads at grade. A central median strip separates the two lanes of the main road, and isolation facilities separate the main and auxiliary roads. The design speed is typically 60-100 km / h, and there are risks associated with merging, diverging, and ramp entry / exit.

[0026] Urban non-expressways: All roads in a city other than expressways, including urban arterial roads, secondary arterial roads, and local roads. They are completely open, with numerous at-grade intersections and traffic lights, allowing pedestrians, non-motorized vehicles, and motorized vehicles to share the road. The design speed is usually 20-60 km / h, and the traffic participants are complex, posing various risks such as pedestrians crossing the road, non-motorized vehicles changing lanes, and vehicles cutting in.

[0027] AEB: Automatic Emergency Braking.

[0028] ABS: Anti-lock Braking System.

[0029] ESC: Electronic Stability Control.

[0030] BBF: Basic Brake Function.

[0031] The core concept of this invention is to construct a two-dimensional risk assessment system based on multi-sensor fusion perception and intelligent driving domain controller decision-making, encompassing both inherent environmental risks and dynamic obstacle risks. The maximum value of the two risk coefficients is used as the final emergency braking risk factor. Based on this risk factor, adaptive zoning and active adjustment of brake disc clearance are achieved. In low-risk scenarios, this invention increases disc clearance to reduce wheel-side drag and improve vehicle range; in high-risk scenarios, it decreases disc clearance to shorten braking free travel and improve braking response speed. This fundamentally solves the industry pain point of existing EMB (Electromechanical Braking) systems failing to simultaneously achieve low drag optimization and braking safety redundancy. Furthermore, the zoning control strategy avoids high-frequency clearance adjustments, ensuring the lifespan of the EMB electromechanical brake actuators and adapting to the braking requirements of new energy vehicles and advanced intelligent driving systems.

[0032] Example 1 like Figure 1 As shown, an active adjustment system for EMB platter gap includes: The emergency braking risk factor calculation module sets a basic driving risk value based on the driving environment, sets a pedestrian flow correction coefficient based on the total pedestrian and non-motorized vehicle flow density, sets a vehicle flow correction coefficient based on the motor vehicle flow density, obtains a first risk coefficient based on the basic driving risk value, pedestrian flow correction coefficient, and vehicle flow correction coefficient, sets a second risk coefficient based on the AEB trigger time, and obtains the emergency braking risk factor based on the first risk coefficient and the second risk coefficient. The disc clearance adjustment module sets the disc clearance target value to the maximum permissible disc clearance when the emergency braking risk factor is less than or equal to the first threshold. When the emergency braking risk factor is greater than the first threshold, it sets the disc clearance target value according to the principle that the emergency braking risk factor and the disc clearance target value are negatively correlated, and adjusts the disc clearance according to the disc clearance target value.

[0033] The hardware execution architecture of this system is divided into three layers, providing hardware support for the entire process control: Environmental perception layer: including vehicle-mounted forward-looking camera, millimeter-wave radar, lidar, V2X vehicle-road cooperative module, vehicle speed sensor, wheel speed sensor, responsible for collecting data on vehicle driving environment, target objects, and vehicle motion status from all dimensions; Decision control layer: including intelligent driving domain controller and EMB brake controller, responsible for environmental identification, risk coefficient calculation, risk factor fusion decision, gap target value mapping and control command issuance; The actuator layer consists of the electromechanical braking system actuators that are independently arranged for the four wheels of the vehicle. Each actuator integrates a servo drive motor, a reduction transmission assembly, a brake caliper, a brake disc, brake blocks, and a push rod displacement sensor. It is responsible for performing clearance adjustment actions and providing real-time feedback on the actual clearance value.

[0034] The intelligent driving domain controller obtains the attribute information of the current road environment by combining traffic signs, lane lines, and road boundary information identified by the vehicle-mounted forward-facing camera, millimeter-wave radar, and lidar with roadside broadcast information received by the V2X vehicle-to-infrastructure (V2X) module. This attribute information includes the driving environment, the total number of pedestrians and non-motorized vehicles within a first preset distance in front of the vehicle, and the number of motor vehicles within a second preset distance in front of the vehicle. The technical solutions involved are existing technologies and will not be elaborated upon here.

[0035] The above technical solution divides emergency braking risk into two independent dimensions: inherent environmental risk and dynamic collision risk. It calculates the first risk coefficient and the second risk coefficient separately, and finally merges them into a unified emergency braking risk factor to ensure coverage of all possible driving scenarios.

[0036] As a specific implementation method, the emergency braking risk factor calculation module obtains the first risk coefficient based on the basic driving risk value, pedestrian flow correction coefficient, and vehicle flow correction coefficient as follows: In the formula, As the first risk factor, To be The calculation result is limited to a limiting function within the range of [0,1], so as to... The value range of is limited to [0,1]. Based on basic driving risk values, Human traffic correction factor This is a traffic flow correction factor. Traffic risks are not linearly cumulative; when multiple high-risk factors coexist, the probability of emergency braking increases sharply. Multiplication can accurately reflect this cumulative amplification effect and the inherent emergency braking probability of different road types.

[0037] Based on the classification of driving environments into closed highways, urban expressways, urban non-expressways, and commercial, residential, or school zones, a basic driving risk value is set with progressively increasing values. For example, set the following basic driving risk values. The value range is determined by the gear selection, and the basic driving risk value is defined for each gear. The value is preset according to the actual situation: When driving in a closed highway environment With no lateral crossing targets on the closed road, the risks of merging / diverting traffic are controllable, and the probability of sudden emergency braking needs is the lowest. When driving on an urban expressway Semi-closed roads pose risks of merging and diverging traffic, and the probability of sudden emergency braking needs is moderately low. When driving in an urban non-expressway environment Open roads present risks of intersections and pedestrian crossings, and the probability of sudden emergency braking needs is moderately high. When the driving environment is a commercial, residential, or school area. The area is characterized by dense pedestrian traffic, a high risk of sudden crosswalks, and the highest probability of needing to brake suddenly.

[0038] Based on the total number of pedestrians and non-motorized vehicles within a first preset distance in front of the vehicle and a pedestrian flow correction coefficient Based on the principle of positive correlation, a correction coefficient for pedestrian flow is set. ,For example: The pedestrian flow correction coefficient is based on the total number of pedestrians and non-motorized vehicles within 100 meters in front of the vehicle. When there are no pedestrians or non-motorized vehicles... When there is low foot traffic medium-density traffic High-density pedestrian traffic ; Based on the number of motor vehicles and traffic flow correction coefficient within the second preset distance in front of the vehicle Based on the principle of positive correlation, a traffic flow correction coefficient is set. ,For example: Based on the number of motor vehicles within 200m in front of the vehicle, when there are no vehicles... When there is low-density traffic medium-density traffic flow High-density traffic flow ; As a specific implementation method, the method for setting the second risk coefficient based on the AEB trigger time in the emergency braking risk factor calculation module is as follows: Based on AEB trigger time Second risk coefficient Based on the principle of negative correlation, a second risk coefficient is set. The smaller the value, the closer it is to the AEB (Automatic Emergency Braking) trigger time, and the higher the risk of sudden emergency braking. The higher the value, the more accurately it can detect the immediate collision risk caused by sudden obstacles. The value range is limited to [0,1].

[0039] AEB trigger time The engineering definition is: the corresponding functional module of AEB within the intelligent driving domain controller, based on the current vehicle speed, relative distance and speed to the obstacle ahead, and obstacle type, calculates in real time the remaining time before the preset minimum level of braking trigger time of AEB; when At this time, it means that AEB has officially triggered a braking request. The engineering definition is deeply coupled with the vehicle's AEB calibration logic, allowing direct reuse of existing AEB calculation results without the need for new complex algorithms, thus possessing extremely high mass production adaptability. For example, the following second risk coefficient can be set. The value range, and the basic driving risk value within each range. The value depends on the actual situation and the AEB trigger time. Establish the corresponding mapping relationship: There is no immediate risk of AEB being triggered. ; Low risk of AEB triggering. ; Risk of AEB being triggered in China ; High risk of AEB triggering ; Extremely high risk of AEB triggering. ; As a specific implementation method, the emergency braking risk factor calculation module obtains the emergency braking risk factor based on the first risk coefficient and the second risk coefficient as follows: The first risk factor Second risk coefficient The maximum value in is used as the emergency braking risk factor. Regardless of the inherent environmental risks (reflected in the first risk coefficient) The risk is either high or a dynamic risk triggered by instantaneous AEB (reflected in the second risk coefficient). The higher risk level allows for adjustments based on a higher risk grade, completely avoiding the blind spots of single-dimensional risk assessment. This ensures that even in low-inherent-risk scenarios (such as closed highways), if a sudden obstacle leads to a second risk factor, adjustments can be made accordingly. Even with a sudden increase in risk, the system can still perform gap adjustments at a high-risk level; conversely, in high-inherent-risk scenarios (such as school zones), the system will maintain a high level of safety alert even if there is no immediate risk of collision. For example, when a vehicle is traveling on a closed highway... (Low inherent risk) If an obstacle appears ahead, , At this time, the risk factor of emergency braking By setting the value to 0.8, the high-risk gap control strategy is switched to complete the gap reduction in advance before AEB is triggered, thus avoiding the problem of delayed braking response when AEB is triggered in low-inherent-risk scenarios. This solves the problem that existing technologies can only perform braking pre-filling and gap adjustment after AEB is activated.

[0040] When the first risk coefficient Or the second risk factor If the information cannot be obtained, the emergency braking risk factor is set to a preset value. For example, when the environmental perception sensor fails, the first risk factor is... Unable to obtain successfully The value is fixed at 0.6, the vehicle enters downgrade mode, and a fault code is reported to ensure basic braking safety.

[0041] As a specific implementation method, the specific method for adjusting the disk gap according to the target value in the disk gap adjustment module is as follows: EMB controls the drive motor via a position loop to retract the brake piston to the corresponding position of the target disc clearance. Specifically: during braking, the drive motor drives the brake piston forward until a sudden increase in drive motor current or torque is detected, indicating that the friction pads have just contacted the brake disc, and the drive motor position at this moment is recorded as the zero point; using this zero point as a reference, the required retraction angle of the drive motor is calculated based on the target disc clearance; the position loop then controls the drive motor to retract the brake piston to the corresponding position of the target disc clearance.

[0042] The position loop is a closed-loop control mode that uses the drive motor rotation angle and the brake piston retraction displacement as control targets. The drive motor rotation angle is collected in real time via a motor encoder and compared with the preset target rotation angle corresponding to the brake piston retraction stroke. The motor rotation is then adjusted in a closed loop to precisely stop at the target position.

[0043] When the braking system receives a braking request from the vehicle's main functions, it immediately interrupts the current gap adjustment process and responds to the corresponding braking torque command of the vehicle's main functions' braking request. The control priority of disc gap adjustment is lower than that of the vehicle's main functions' braking request, which comes from one of AEB, ABS, ESC, or BBF. This design avoids braking response delay caused by the conflict between gap adjustment action and braking request, providing the ultimate guarantee for driving safety.

[0044] The disk gap adjustment module establishes risk factors. Target value of disk gap The mapping relationship is established, and the high-frequency adjustment problem of the gap is avoided through the partition grid control strategy, thus protecting the lifespan of the EMB actuator.

[0045] First, the effective adjustment range of the EMB platter gap is calibrated as follows: ,in: The minimum allowable disc clearance is set to 0mm in this embodiment to ensure that the brake pads and brake discs do not come into contact and drag, thereby achieving the shortest braking travel and the fastest braking response speed. The maximum permissible disc clearance is calibrated to 0.3mm in this embodiment, which achieves the lowest wheel-side drag torque while ensuring the emergency response capability of the braking system.

[0046] Gap mapping follows a negative correlation principle: lower risk corresponds to larger gaps, and higher risk corresponds to smaller gaps, in conjunction with a set risk threshold. The specific mapping rules are as follows: Extremely low risk range: The probability of an emergency braking requirement within this range is extremely low. Fixed as (Can be adjusted according to vehicle calibration requirements) The probability of sudden emergency braking demand is extremely low within this range. Maximizing the disc clearance can significantly reduce wheel-side drag torque and optimize the vehicle's range performance. Medium- to high-risk areas: The risk of sudden emergency braking increases within this range. Therefore, a segmented fixed disc clearance control strategy is adopted to mitigate the emergency braking risk factor. The value range is divided into 7 consecutive, non-overlapping zones, each zone corresponding to a unique fixed disc clearance target value, which is only applied when the emergency braking risk factor... The target value for the platter gap is only switched when the distance crosses the zone boundary and the duration is ≥10ms, thus completely avoiding the problem of high-frequency adjustment of the platter gap caused by minor fluctuations in I. The specific zone and corresponding platter gap calibration are as follows: Area 1: , ; Area 2: , ; Area 3: , ; Area 4: , ; Area 5: , ; Area 6: , ; Area 7: , .

[0047] like Figure 3 As shown, with the emergency braking risk factor By gradually increasing the disc clearance, the brake free travel is shortened, and the braking response speed is improved. In extremely high-risk scenarios, such as zone 7, the disc clearance can be adjusted to 0mm to eliminate brake free travel in advance, so that braking clamping force can be generated immediately when AEB is triggered, maximizing the reduction of braking distance.

[0048] The present invention will be described below with reference to specific data: Cruise operation on closed highways: The vehicle was cruising at 110 km / h on a closed highway, and the relevant vehicle environment recognition module identified the road type as a closed highway. There are no pedestrians or vehicles ahead, thus yielding a pedestrian flow correction coefficient. Traffic flow correction factor is 1. The risk coefficient is 0.7, the highest among all risk factors. No obstacles ahead, second risk factor Risk factors This falls within the extremely low risk range. EMB adjusted the disc gap to 0.3mm, reducing the vehicle's drag torque from 3Nm to 1.2Nm compared to the conventional 0.15mm disc gap, thereby improving the vehicle's range.

[0049] Driving conditions in school zones: The vehicle was traveling at 30 km / h into the school zone. The relevant vehicle environment recognition unit identified the road type as a school zone and noted the high pedestrian traffic, thus calculating the first risk factor. At the same time, pedestrians appeared to be crossing the road ahead. Second risk factor Risk factors Corresponding to section 7, EMB immediately adjusted the platter gap to 0. This refers to the disc contact state, which eliminates the brake free travel before AEB is triggered. If AEB is officially triggered, it can immediately respond and clamp, maximizing the safety of pedestrians and vehicles.

[0050] In summary, this invention achieves a dynamic balance between prioritizing energy consumption performance under low safety risks and prioritizing driving safety under high safety risks by deeply integrating risk quantification and EMB disc gap control strategies. It solves the lag problem of existing technologies that can only adjust disc gap after AEB activation. Compared with technologies that rely solely on pre-filling after AEB activation, the technical solution of this invention reduces brake free travel by more than 80%, AEB braking response time by more than 30%, and braking distance by significantly shortening. At the same time, it avoids energy loss caused by maintaining a small disc gap for a long time in pursuit of safety, and significantly improves the overall performance of EMB. In low-risk scenarios, minimizing wheel-side drag can achieve a 3% to 5% increase in the range of pure electric vehicles, while maximizing braking response speed in high-risk scenarios. By using a strategy of switching between fixed gaps in a partitioned grid and boundary hysteresis, the problem of high-frequency gap adjustment is completely avoided, reducing the frequency of EMB actuator operations and extending service life by more than 30%. Based on existing mass-produced vehicle sensors, intelligent driving domain controllers, and AEB architecture, no additional hardware costs are required, and the trigger time calculation results of AEB can be directly reused, adapting to existing new energy vehicles and advanced intelligent driving systems, and possessing extremely high mass production value.

[0051] Example 2 refer to Figure 2 An active adjustment method for EMB platter gap, comprising: The basic driving risk value is set according to the driving environment, the pedestrian flow correction coefficient is set according to the total flow density of pedestrians and non-motorized vehicles, the vehicle flow correction coefficient is set according to the flow density of motor vehicles, the first risk coefficient is obtained according to the basic driving risk value, the pedestrian flow correction coefficient and the vehicle flow correction coefficient, the second risk coefficient is set according to the AEB trigger time, and the first risk coefficient and the second risk coefficient are merged to obtain the emergency braking risk factor. When the emergency braking risk factor is less than or equal to the first threshold, the disc clearance target value is set as the maximum permissible disc clearance. When the emergency braking risk factor is greater than the first threshold, the disc clearance target value is set according to the principle that the emergency braking risk factor and the disc clearance target value are negatively correlated, and the disc clearance is adjusted according to the disc clearance target value.

[0052] Example 3 A computer program product includes a computer program / instructions that, when executed by a processor, implement the active adjustment method for EMB platter gap in Embodiment 2.

[0053] The contents not described in detail in this specification are prior art known to those skilled in the art. Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0054] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0055] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0056] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit its scope of protection. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that after reading the present invention, they can still make various changes, modifications or equivalent substitutions to the specific implementation of the invention, but these changes, modifications or equivalent substitutions are all within the scope of protection of the pending claims of the invention.

Claims

1. An active adjustment system for EMB platter gap, characterized in that, include: The emergency braking risk factor calculation module sets a basic driving risk value based on the driving environment, sets a pedestrian flow correction coefficient based on the total pedestrian and non-motorized vehicle flow density, sets a vehicle flow correction coefficient based on the motor vehicle flow density, obtains a first risk coefficient based on the basic driving risk value, pedestrian flow correction coefficient, and vehicle flow correction coefficient, sets a second risk coefficient based on the AEB trigger time, and obtains the emergency braking risk factor based on the first risk coefficient and the second risk coefficient. The disc clearance adjustment module sets the disc clearance target value to the maximum permissible disc clearance when the emergency braking risk factor is less than or equal to the first threshold. When the emergency braking risk factor is greater than the first threshold, it sets the disc clearance target value according to the principle that the emergency braking risk factor and the disc clearance target value are negatively correlated, and adjusts the disc clearance according to the disc clearance target value.

2. The active adjustment system for EMB platter gap according to claim 1, characterized in that, The specific method for setting the basic driving risk value based on the driving environment in the emergency braking risk factor calculation module is as follows: The basic driving risk values ​​are set in ascending order based on the driving environment classification of closed highways, urban expressways, urban non-expressways, and commercial, residential, or school zones.

3. The active adjustment system for EMB platter gap according to claim 1, characterized in that, In the emergency braking risk factor calculation module, the specific method for setting the pedestrian flow correction coefficient based on the total pedestrian and non-motorized vehicle flow density is as follows: Based on the principle that the total number of pedestrians and non-motorized vehicles within the first preset distance in front of the vehicle is positively correlated with the pedestrian flow correction coefficient, a pedestrian flow correction coefficient is set.

4. The active adjustment system for EMB platter gap according to claim 1, characterized in that, In the emergency braking risk factor calculation module, the specific method for setting the traffic flow correction coefficient based on the vehicle traffic flow density is as follows: Based on the principle that the number of motor vehicles within the second preset distance in front of the vehicle and the traffic flow correction coefficient are positively correlated, the traffic flow correction coefficient is set.

5. The active adjustment system for EMB platter gap according to claim 1, characterized in that, In the emergency braking risk factor calculation module, the specific method for obtaining the first risk coefficient based on the basic driving risk value, pedestrian flow correction coefficient, and vehicle flow correction coefficient is as follows: In the formula, As the first risk factor, To be The calculation results are limited to the amplitude-limiting function within the range of [0,1]. Based on basic driving risk values, Human traffic correction factor This is a traffic flow correction factor.

6. The active adjustment system for EMB platter gap according to claim 1, characterized in that, In the emergency braking risk factor calculation module, the specific method for setting the second risk coefficient based on the AEB trigger time is as follows: Based on the principle that the AEB trigger time and the second risk coefficient are negatively correlated, the second risk coefficient is set.

7. The active adjustment system for EMB platter gap according to claim 1, characterized in that, In the emergency braking risk factor calculation module, the specific method for obtaining the emergency braking risk factor based on the first risk coefficient and the second risk coefficient is as follows: The maximum value between the first risk coefficient and the second risk coefficient is taken as the emergency braking risk factor; When the first or second risk factor cannot be obtained, the emergency braking risk factor is set to a preset value.

8. The active adjustment system for EMB platter gap according to claim 1, characterized in that, The specific method for adjusting the disk gap according to the target value in the disk gap adjustment module is as follows: EMB controls the drive motor via a position loop to retract the brake piston to the corresponding position of the target value of the disc clearance; When the EMB receives a braking request from the vehicle function, it immediately interrupts the current disc clearance adjustment process and responds to the corresponding braking torque command of the vehicle function's braking request. The control priority of disc gap adjustment is lower than the braking request of the vehicle function, which comes from one of AEB, ABS, ESC, and BBF.

9. A method for actively adjusting the gap between EMB platters, characterized in that, include: The basic driving risk value is set according to the driving environment, the pedestrian flow correction coefficient is set according to the total flow density of pedestrians and non-motorized vehicles, the vehicle flow correction coefficient is set according to the flow density of motor vehicles, the first risk coefficient is obtained according to the basic driving risk value, the pedestrian flow correction coefficient and the vehicle flow correction coefficient, the second risk coefficient is set according to the AEB trigger time, and the first risk coefficient and the second risk coefficient are merged to obtain the emergency braking risk factor. When the emergency braking risk factor is less than or equal to the first threshold, the disc clearance target value is set as the maximum permissible disc clearance. When the emergency braking risk factor is greater than the first threshold, the disc clearance target value is set according to the principle that the emergency braking risk factor and the disc clearance target value are negatively correlated, and the disc clearance is adjusted according to the disc clearance target value.

10. A computer program product comprising a computer program / instructions, characterized in that, When the computer program / instructions are executed by the processor, they implement the active adjustment method for EMB platter gap as described in claim 9.

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