Control Method of Electro-Mechanical Braking System and Electronic Device

Abstract

The present application provides a control method for an electromechanical braking system and an electronic device. The method detects that the brake pedal in a vehicle is triggered, obtains the stroke information of the brake pedal, and in response to the current stroke not exceeding a preset contact stroke, controls a brake pad in the electromechanical braking system to move towards a brake disc according to the stroke information. Furthermore, in response to the current stroke being greater than the preset contact stroke and not exceeding a preset pre-tightening stroke, the actual clamping force generated after the brake pad contacts the brake disc is obtained. When the actual clamping force does not reach the preset pre-tightening force, the clamping force between the brake pad and the brake disc is adjusted according to the stroke information, so as to eliminate mechanical clearance and achieve pre-tightening before the preset pre-tightening stroke, thereby establishing a braking reference state in the early stage when the user triggers the brake pedal, eliminating the abruptness and delay during braking, ensuring the followability of the user's subsequent braking control, and further ensuring braking response agility, handling stability, and riding comfort.

Description

Technical Field

[0001] This application relates to the technical field of automotive braking, and particularly to a control method for an electro-mechanical braking system and an electronic device. Background Art

[0002] In the related art, most EMB (Electro-Mechanical Brake) directly outputs a clamping force in an electrically controlled manner based on the pedal stroke and driver input.

[0003] However, the mechanical clearance between mechanical parts in the EMB can lead to insufficiently rapid braking response and uneven pedal feel. Moreover, the mechanical clearance can also cause a sense of abruptness and delay during braking, resulting in poor user control followability and thus causing user anxiety in driving control. In addition, when the user triggers a relatively deep brake pedal stroke, the clamping force output by the EMB will have a large instantaneous jump, which will further affect the handling stability and ride comfort of the vehicle. Summary of the Invention

[0004] In view of the above-mentioned defects or deficiencies in the prior art, this application aims to provide a control method for an electro-mechanical braking system and an electronic device to solve problems such as insufficiently rapid braking response, uneven pedal feel, poor handling stability, and low ride comfort.

[0005] An embodiment of this application provides a control method for an electro-mechanical braking system, and the method includes:

[0006] When it is detected that the brake pedal in the vehicle is triggered, obtain the stroke information of the brake pedal, where the stroke information includes the current stroke and the corresponding stroke change rate;

[0007] In response to the current stroke not exceeding a preset contact stroke, control the brake pad in the electro-mechanical braking system to move towards the brake disc based on the stroke information;

[0008] In response to the current stroke being greater than the preset contact stroke and not exceeding a preset pre-tightening stroke, obtain the actual clamping force generated after the brake pad contacts the brake disc, and adjust the clamping force between the brake pad and the brake disc based on the stroke information when the actual clamping force has not reached the preset pre-tightening force.

[0009] Optionally, controlling the brake pad in the electro-mechanical braking system to move towards the brake disc based on the stroke information includes:

[0010] Determine the target displacement of the brake pad based on the current stroke, the stroke change rate, and a pre-constructed displacement mapping function;

[0011] Control the movement of the brake pad according to the target displacement.

[0012] Optionally, determining the target displacement of the brake pad based on the current stroke, the stroke change rate, and a pre-constructed displacement mapping function includes:

[0013] Obtain a preset fast contact interval close to the preset contact stroke;

[0014] If the current stroke is within the preset fast contact interval, adjust the parameters in the displacement mapping function, and input the current stroke and the stroke change rate into the adjusted displacement mapping function to determine the target displacement of the brake pad.

[0015] Optionally, adjusting the clamping force between the brake pad and the brake disc based on the stroke information includes:

[0016] Determine the clamping force deviation between the preset pre-tightening force and the actual clamping force, and the stroke difference between the current stroke and the preset pre-tightening stroke;

[0017] Based on the stroke difference and the clamping force deviation, determine the current clamping force increment;

[0018] Adjust the clamping force between the brake pad and the brake disc based on the current clamping force increment.

[0019] Optionally, determining the current clamping force increment based on the stroke difference and the clamping force deviation includes:

[0020] According to the stroke difference and the stroke change rate, determine the estimated time for the brake pedal to reach the preset pre-tightening stroke from the current stroke;

[0021] If the estimated time is less than a preset time threshold, determine the emergency supplementary rate of the clamping force according to the estimated time and the clamping force deviation;

[0022] Determine the current clamping force increment according to the emergency supplementary rate and a preset sampling time interval.

[0023] Optionally, the method further includes:

[0024] In response to the current stroke being greater than the preset pre-tightening stroke, obtain the actual clamping force between the brake pad and the brake disc;

[0025] Based on the actual clamping force, the stroke difference between the current stroke and the preset pre-tightening stroke, and the slope of a pre-calibrated stroke-clamping force curve, determine the target clamping force, and control the clamping force between the brake pad and the brake disc according to the target clamping force.

[0026] Optionally, before controlling the clamping force between the brake pad and the brake disc according to the target clamping force, the method further includes:

[0027] Obtaining the driving information of the vehicle;

[0028] Based on the driving information and the stroke information, determining whether the vehicle meets a preset clamping force smooth transition condition; if so, reducing the target clamping force;

[0029] Wherein, the clamping force smooth transition condition includes: the vehicle deceleration in the driving information is less than a preset deceleration threshold, and the stroke change rate is lower than a preset change rate threshold, and the current stroke does not exceed a preset smooth stroke.

[0030] Optionally, reducing the target clamping force includes:

[0031] Based on the current stroke, the preset pre-tightening stroke, and the preset smooth stroke, determining a current smoothing parameter;

[0032] According to the current smoothing parameter, the actual clamping force, and the target clamping force, re-determining a new target clamping force.

[0033] Optionally, the method further includes:

[0034] Obtaining the operating state information of the electromechanical braking system, and determining whether the vehicle meets a preset parameter adjustment condition according to the operating state information;

[0035] If so, updating at least one of the preset contact stroke, the preset pre-tightening stroke, and the preset pre-tightening force.

[0036] An embodiment of the present application further provides an electronic device, where the electronic device includes:

[0037] A processor and a memory;

[0038] The processor is configured to execute the steps of the control method of the electromechanical braking system provided in any embodiment of the present application by calling a program or an instruction stored in the memory.

[0039] An embodiment of the present application further provides a computer-readable storage medium, where the computer-readable storage medium stores a program or an instruction, and the program or the instruction causes a computer to execute the steps of the control method of the electromechanical braking system provided in any embodiment of the present application.

[0040] In summary, the present application proposes a control method for an electro-mechanical braking system. The method detects that the brake pedal in the vehicle is triggered, obtains the stroke information of the brake pedal, and in response to the current stroke not exceeding the preset contact stroke, controls the brake pads in the electro-mechanical braking system to move towards the brake disc according to the stroke information. Furthermore, in response to the current stroke being greater than the preset contact stroke and not exceeding the preset pre-tightening stroke, the actual clamping force generated after the brake pads come into contact with the brake disc is obtained. In the case where the actual clamping force does not reach the preset pre-tightening force, the clamping force between the brake pads and the brake disc is adjusted according to the stroke information to achieve the control of the electro-mechanical braking system. This method can eliminate mechanical clearances when the pedal stroke reaches the preset contact stroke, and can also establish a basic pre-tightening force when the pedal stroke reaches the preset pre-tightening stroke, achieving the purpose of eliminating mechanical clearances and realizing pre-tightening before the preset pre-tightening stroke, ensuring that the actual clamping force at the preset pre-tightening stroke can reach the basic pre-tightening force, so as to establish a braking reference state in the early stage when the user triggers the brake pedal. This pre-tightening does not generate effective braking force, can eliminate the sudden feeling and delay during braking, ensure the followability of the user's subsequent braking control, and further ensure the braking response agility, handling stability and riding comfort of the vehicle. It is applicable to various operating conditions and can achieve more precise and safer braking control. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0042] Figure 1 It is a flowchart of a control method for an electro-mechanical braking system provided by an embodiment of the present application;

[0043] Figure 2 It is a control flowchart of an electro-mechanical braking system provided by an embodiment of the present application;

[0044] Figure 3 It is a schematic structural diagram of a control device for an electro-mechanical braking system provided by an embodiment of the present application;

[0045] Figure 4 It is a schematic structural diagram of an electronic device provided by an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0046] The present application will be further described in detail below with reference to the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the relevant invention, rather than limiting the invention. Additionally, it should be noted that for ease of description, only the parts related to the invention are shown in the drawings.

[0047] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and embodiments.

[0048] As mentioned in the background art, in view of the problems in the prior art, the present application proposes a control method for an electro-mechanical braking system. Figure 1 is a flowchart of a control method for an electro-mechanical braking system provided by an embodiment of the present application. This method is applicable to a vehicle equipped with an electro-mechanical braking system (EMB), and can be executed by a control device of the electro-mechanical braking system. This device can be set in an electronic device in a hardware and / or software manner.

[0049] See Figure 1 , the control method of the electro-mechanical braking system specifically includes:

[0050] S110. Detect that the brake pedal in the vehicle is triggered, and obtain the travel information of the brake pedal.

[0051] Among them, the travel information includes the current travel and the corresponding travel change rate. The current travel can be the result of detecting the travel of the vehicle's brake pedal at the current moment, which can be understood as the depth of the brake pedal and can reflect the user's braking demand. The current travel can be described by the actual displacement distance starting from the free position (not depressed), or can be described by the ratio between the actual displacement distance and the displacement distance corresponding to the fully depressed position (such as 0 to 1).

[0052] Exemplarily, in order to ensure the accuracy of the current travel of the brake pedal, the current travel of the brake pedal can be detected by means of multi-sensor fusion. For example, corresponding weights can be set for each sensor (such as Hall effect sensor, capacitive sensor, potentiometer sensor, or linear variable differential transformer, etc.), and then the travel detected by each sensor at the current moment is fused according to the weights to obtain the final current travel.

[0053] Among them, the travel change rate can be the result of detecting the travel change rate of the vehicle's brake pedal at the current moment, which can be understood as the depression speed of the brake pedal and is used to judge whether the user is making an emergency brake or a slow brake. The unit of the travel change rate can be m / s.

[0054] Exemplarily, the rate of change of the travel of the brake pedal can be detected by an acceleration sensor or a piezoelectric accelerometer. To further ensure the accuracy of the current travel of the brake pedal, the fusion result of each sensor can be optimized according to the rate of change of the travel of the brake pedal.

[0055] In the embodiments of the present application, to ensure the safety of the braking control of the EMB, before that, the states of the actuator and each sensor in the EMB can also be detected. If there are no abnormalities in the actuator and each sensor, the subsequent control process can be executed. Otherwise, a fault prompt message can be displayed to the user through the vehicle-mounted interface in a timely manner, and the user can be prompted to slowly pull over to the side of the road.

[0056] S120. In response to the current travel not exceeding the preset contact travel, control the brake pad in the electromechanical braking system to move towards the brake disc based on the travel information.

[0057] Among them, the preset contact travel can be the pedal travel at which the brake pad and the brake disc complete contact calibrated in advance. In the embodiments of the present application, in order to eliminate the mechanical gap between the brake pad and the brake disc as soon as possible when the user just triggers the brake pedal, therefore, the preset contact travel can be obtained through calibration.

[0058] It should be noted that considering that there may be differences in the components or component structures carried in the EMBs of different vehicle models, therefore, the preset contact travel can be calibrated separately for different vehicles.

[0059] Specifically, after detecting that the current travel pedal is triggered (i.e., stepped on), if the obtained current travel does not exceed the preset contact travel, it means that the user has just triggered the brake pedal at this time, and the braking demand is extremely small. At this time, the mechanical gap can be eliminated, that is, in the mechanical gap elimination stage, the brake pad in the EMB can be controlled to move towards the brake disc according to the travel information, so as to reduce the mechanical gap between the brake pad and the brake disc, so that when the current travel reaches the preset contact travel, the brake pad and the brake disc complete contact, and the mechanical gap between the two is completely eliminated.

[0060] Exemplarily, controlling the brake pad in the electromechanical braking system to move towards the brake disc based on the travel information can be: determining the distance that the brake pad needs to move according to the gap between the current travel and the preset contact travel, and the length of the mechanical gap between the brake pad and the brake disc, so as to control the brake pad to move towards the brake disc.

[0061] In a specific implementation manner, controlling the brake pad in the electromechanical braking system to move towards the brake disc based on the travel information includes:

[0062] Determining the target displacement of the brake pad based on the current travel, the rate of change of travel, and the pre-constructed displacement mapping function; controlling the movement of the brake pad according to the target displacement.

[0063] Among them, the displacement mapping function can describe the mapping relationship between the stroke, the stroke change rate, and the displacement of the brake pad; the current stroke and the stroke change rate can be input into the displacement mapping function to calculate the target displacement.

[0064] Exemplarily, based on the current stroke, the stroke change rate, and the pre-constructed displacement mapping function, determining the target displacement of the brake pad can be expressed by the following formula:

[0065] ;

[0066] In the formula, is the target displacement of the brake pad, is the gain, is the current stroke of the brake pad, is the stroke change rate of the brake pad, is the speed compensation factor. and can be obtained through calibration.

[0067] After obtaining the target displacement, a displacement control instruction can be generated according to the target displacement, and then the displacement control instruction can be sent to the actuator so that the actuator controls the movement of the brake pad based on the displacement control instruction.

[0068] Through the above embodiments, the target displacement of the brake pad can be determined according to the current stroke and the stroke change rate, realizing dynamic clearance elimination. Considering that the current stroke can reflect the gap from the preset contact stroke, and the stroke change rate can reflect the urgency of the user's braking, by combining the current stroke and the stroke change rate, it can be ensured that the movement of the brake pad more conforms to the user's braking requirements. When the current stroke is larger or the stroke change rate is higher, the moving distance of the brake pad is more, thus ensuring the reliability of clearance elimination.

[0069] In the embodiments of the present application, in order to further ensure the reliability of clearance elimination, when the current stroke is about to reach the preset contact stroke, the displacement mapping function can also be adjusted so that the brake pad quickly approaches the actual contact position to complete the contact between the brake pad and the brake disc.

[0070] In one example, based on the current stroke, the stroke change rate, and the pre-constructed displacement mapping function, determining the target displacement of the brake pad includes:

[0071] Obtaining a preset fast contact interval close to the preset contact stroke; if the current stroke is within the preset fast contact interval, adjusting the parameters in the displacement mapping function, and inputting the current stroke and the stroke change rate into the adjusted displacement mapping function to determine the target displacement of the brake pad.

[0072] Among them, the preset quick contact interval can be a travel interval approaching the preset contact travel, such as , , being the preset contact travel.

[0073] Specifically, if the current travel does not exceed the preset contact travel and the current travel is within the preset quick contact interval, then in order to quickly eliminate the mechanical clearance before approaching the preset contact travel, the displacement mapping function can be adjusted to the quick elimination mode, and the parameters in the displacement mapping function can be adjusted. For example, the gain among them can be adjusted, and then the current travel and the travel change rate are input into the adjusted displacement mapping function to obtain the target displacement.

[0074] Of course, if the current travel does not exceed the preset contact travel and the current travel is not within the preset quick contact interval, at this time, the current travel and the travel change rate can be directly input into the displacement mapping function to gradually make the brake pad approach the brake disc to ensure the smoothness of braking.

[0075] Through the above examples, when the current travel is far from reaching the preset contact travel, the brake pad can be gradually made to approach the brake disc to ensure the smoothness of braking. When the current travel is about to reach the preset contact travel, the displacement mapping function can be adjusted so that the brake pad quickly approaches the actual contact position, completing the contact between the brake pad and the brake disc, realizing quick compensation for the clearance, and further ensuring the reliability of mechanical clearance elimination.

[0076] It should be noted that in the above mechanical clearance elimination stage, the movement control of the brake pad can be repeatedly executed. That is, after detecting that the brake pedal is triggered, the current travel and the corresponding travel change rate can be obtained in real time. If the current travel does not exceed the preset contact travel, the target displacement can be calculated and the brake pad can be controlled to move towards the brake disc until the current travel reaches the preset contact travel, at which time the contact between the brake pad and the brake disc is completed.

[0077] S130. In response to the current travel being greater than the preset contact travel and not exceeding the preset pre-tightening travel, obtain the actual clamping force generated after the brake pad contacts the brake disc. When the actual clamping force does not reach the preset pre-tightening force, adjust the clamping force between the brake pad and the brake disc based on the travel information.

[0078] Among them, the preset pre-tightening travel can be the maximum travel for pre-tightening the brake pad and the brake disc pre-calibrated. In the embodiments of the present application, in order to quickly eliminate the mechanical clearance and establish pre-tightening when the user just triggers the brake pedal, therefore, the preset contact travel can be obtained through calibration; different vehicles can respectively obtain the preset pre-tightening travel through calibration.

[0079] In the embodiment of the present application, after the user triggers the brake pedal, the mechanical clearance elimination stage can be entered first until the currently obtained current stroke reaches the preset contact stroke. At this time, the brake pad and the brake disc are in contact, and the mechanical clearance is eliminated. If the user continues to trigger the brake pedal, the pre-tightening establishment stage can be entered.

[0080] Specifically, if the current stroke is greater than the preset contact stroke and does not exceed the preset pre-tightening stroke, it means that the mechanical clearance between the brake pad and the brake disc has been eliminated at this time, and it is in the pre-tightening establishment stage. The clamping force between the brake pad and the brake disc can be adjusted with the goal that the clamping force between the brake pad and the brake disc reaches at least the preset pre-tightening force.

[0081] Among them, the preset pre-tightening force can be a pre-calibrated pre-tightening force, which can further ensure that the clearance between the brake pad and the brake disc is eliminated, and can help prevent large instantaneous jumps during subsequent braking, reduce the sense of abrupt braking and delay, and improve the user's control followability.

[0082] Exemplarily, when the current stroke is greater than the preset contact stroke and does not exceed the preset pre-tightening stroke, the actual clamping force measured by the actuator (the unit can be N) can be obtained, and then it can be determined whether the actual clamping force reaches the preset pre-tightening force. If not, the clamping force between the brake pad and the brake disc can be adjusted according to the stroke information; if it exceeds the preset pre-tightening force, the clamping force can be kept stable.

[0083] In a specific implementation manner, adjusting the clamping force between the brake pad and the brake disc based on the stroke information includes the following steps:

[0084] Step 11: Determine the clamping force deviation between the preset pre-tightening force and the actual clamping force, and the stroke difference between the current stroke and the preset pre-tightening stroke;

[0085] Step 12: Determine the current clamping force increment based on the stroke difference and the clamping force deviation;

[0086] Step 13: Adjust the clamping force between the brake pad and the brake disc based on the current clamping force increment.

[0087] Among them, in step 11, the difference between the preset pre-tightening force and the actual clamping force can be calculated to obtain the clamping force deviation, and the difference between the preset pre-tightening stroke and the current stroke can be calculated to obtain the stroke difference.

[0088] Further, in step 12, the current clamping force increment can be determined based on the travel difference and the clamping force deviation. For example, the clamping force increment per unit travel can be calculated according to the preset pre-tightening force and the difference between the preset pre-tightening travel and the preset contact travel, and then the estimated force deviation can be calculated based on the travel difference between the current travel and the preset pre-tightening travel and the clamping force increment per unit travel. If the clamping force deviation does not reach the estimated force deviation, the current clamping force increment can be obtained based on the difference between the two to supplement the clamping force stage by stage, realizing gradual pre-tightening and improving smoothness.

[0089] Alternatively, the clamping force deviation can be directly determined as the current clamping force increment to complete pre-tightening in one step and improve the pre-tightening efficiency. Considering that there may be a situation where the actual clamping force still does not reach the preset pre-tightening force when the current travel is about to reach the preset pre-tightening travel due to reasons such as actuator control error, in order to ensure that pre-tightening can be completed at the preset pre-tightening travel, an emergency supplement strategy can also be started to quickly supplement the clamping force.

[0090] For the above step 12, in one example, based on the travel difference and the clamping force deviation, determining the current clamping force increment includes the following steps:

[0091] Step 121: Determine the estimated duration for the brake pedal to reach the preset pre-tightening travel from the current travel based on the travel difference and the travel change rate;

[0092] Step 122: If the estimated duration is less than the preset duration threshold, determine the emergency supplement rate of the clamping force based on the estimated duration and the clamping force deviation;

[0093] Step 123: Determine the current clamping force increment based on the emergency supplement rate and the preset sampling time interval.

[0094] Among them, in step 121, the duration required for the brake pedal to reach the travel difference can be predicted based on the travel change rate as the estimated duration for the brake pedal to reach the preset pre-tightening travel from the current travel.

[0095] Further, in step 122, the estimated duration can be compared with the preset duration threshold. If the estimated duration is less than the preset duration threshold, it means that the remaining pre-tightening time is insufficient at this time, and the emergency supplement strategy can be started to determine the emergency supplement rate of the clamping force based on the estimated duration and the clamping force deviation.

[0096] Exemplarily, the number of supplement times at the estimated duration can be determined according to the estimated duration and the preset sampling time interval corresponding to the travel information, and then the clamping force deviation is divided by the number of supplement times to obtain the emergency supplement rate of the clamping force (the unit can be N / s).

[0097] Alternatively, an additional rate can be pre-calibrated in advance, and then, based on the estimated duration and the clamping force deviation, the calibrated additional rate can be dynamically adjusted. If the estimated duration is low, the additional rate is increased; if the clamping force deviation is large, the additional rate is increased.

[0098] Further, in step 123, the emergency additional rate can be multiplied by the preset sampling time interval to obtain the current clamping force increment.

[0099] Through the above steps 121 - 123, when the current stroke is about to reach the preset pre-tightening stroke, the emergency additional strategy can be activated to quickly supplement the clamping force and ensure the reliability of pre-tightening establishment.

[0100] After determining the current clamping force increment, further, in step 13, the clamping force between the brake pad and the brake disc can be adjusted according to the current clamping force increment. For example, a clamping force command can be generated based on the sum of the current clamping force increment and the actual clamping force, and then the clamping force command is sent to the actuator, and the actuator controls the clamping of the brake disc and the brake disc through this clamping force command.

[0101] The above steps 11 - 13 can determine the current clamping force increment based on the clamping force deviation between the preset pre-tightening force and the actual clamping force, as well as the stroke difference between the current stroke and the preset pre-tightening stroke, so as to perform dynamic adjustment of the clamping force, ensure that pre-tightening establishment is completed when the preset pre-tightening stroke is reached, and prevent unexpected delay in braking.

[0102] The control method of the electromechanical braking system provided by the embodiment of the present application detects that the brake pedal in the vehicle is triggered, obtains the stroke information of the brake pedal, in response to the current stroke not exceeding the preset contact stroke, controls the brake pad in the electromechanical braking system to move towards the brake disc according to the stroke information, and then, in response to the current stroke being greater than the preset contact stroke and not exceeding the preset pre-tightening stroke, obtains the actual clamping force generated after the brake pad contacts the brake disc. When the actual clamping force does not reach the preset pre-tightening force, the clamping force between the brake pad and the brake disc is adjusted according to the stroke information to achieve the control of the electromechanical braking system. This method can eliminate the mechanical clearance when the pedal stroke reaches the preset contact stroke, and can also establish the basic pre-tightening force when the pedal stroke reaches the preset pre-tightening stroke, achieving the purpose of eliminating the mechanical clearance and realizing pre-tightening before the preset pre-tightening stroke, ensuring that the actual clamping force at the preset pre-tightening stroke can reach the basic pre-tightening force, so as to establish the braking reference state in the early stage when the user triggers the brake pedal. This pre-tightening does not generate effective braking force, can eliminate the sudden feeling and delay feeling during braking, ensure the followability of the user's subsequent braking control, and then ensure the braking response agility, handling stability and riding comfort of the vehicle, is applicable to a variety of operating conditions, and can achieve more refined and safer braking control.

[0103] After the pre-tightening is established, if the user continues to trigger the brake pedal, the braking force control stage can be entered. In this stage, the current stroke can reflect the user's braking demand, and the target clamping force can be calculated based on the current stroke, so as to realize the control of the braking force.

[0104] In a specific implementation manner, the method provided in the embodiment of the present application further includes the following steps:

[0105] Step 21: In response to the current stroke being greater than the preset pre-tightening stroke, obtain the actual clamping force between the brake pads and the brake disc;

[0106] Step 22: Based on the actual clamping force, the stroke difference between the current stroke and the preset pre-tightening stroke, and the slope of the pre-calibrated stroke-clamping force curve, determine the target clamping force, and control the clamping force between the brake pads and the brake disc according to the target clamping force.

[0107] Among them, the stroke-clamping force curve can be used to describe the mapping relationship between the stroke and the clamping force, and can be obtained by fitting discrete data.

[0108] Specifically, in step 21, if the current stroke is greater than the preset pre-tightening stroke, it means that the clearance elimination and pre-tightening establishment have been completed at this time, and it is in the braking force control stage, and the actual clamping force between the brake pads and the brake disc can be obtained.

[0109] Further, in step 22, the clamping force increment can be calculated according to the stroke difference between the current stroke and the preset pre-tightening stroke and the slope of the stroke-clamping force curve, and then the clamping force increment is added to the actual clamping force to obtain the target clamping force. As shown in the following formula:

[0110] ;

[0111] In the formula, is the target clamping force, is the actual clamping force, is the slope of the stroke-clamping force curve, is the preset pre-tightening stroke, is the current stroke.

[0112] After calculating the target clamping force, further, a control command can be generated according to the target clamping force, and then it is sent to the actuator, and the actuator controls the clamping between the brake pads and the brake disc based on this command.

[0113] Through the above steps 21-step 22, the target clamping force can be determined by the slope of the stroke-clamping force curve, ensuring the determination efficiency of the clamping force, so as to provide a zero-delay braking response in an emergency state.

[0114] During the braking force control phase, to ensure the smooth transition from the pre-tightening establishment phase to the braking force control phase, smooth control can also be performed in the early stage of the braking force control phase to achieve a flexible transition in non-emergency states, effectively alleviating the sense of jump caused by the phase switch, while not affecting the responsiveness of emergency braking.

[0115] In some alternative embodiments, before controlling the clamping force between the brake pads and the brake disc according to the target clamping force, the following steps are further included:

[0116] Step 221, obtain the driving information of the vehicle;

[0117] Step 222, based on the driving information and the stroke information, determine whether the vehicle meets the preset clamping force smooth transition condition. If so, reduce the target clamping force.

[0118] Among them, the driving information may include the vehicle deceleration. The clamping force smooth transition condition may include: the vehicle deceleration in the driving information is less than the preset deceleration threshold, and, the stroke change rate is lower than the preset change rate threshold, and, the current stroke does not exceed the preset smooth stroke.

[0119] Specifically, in step 221, the driving information of the vehicle, such as the vehicle deceleration, can be obtained first through the sensors installed on the vehicle.

[0120] Furthermore, in step 222, it can be determined whether the vehicle meets the preset clamping force smooth transition condition according to the driving information and the stroke information. Among them, the clamping force smooth transition condition may be the condition for smooth control of the clamping force in a non-emergency braking state. For example, determine whether the vehicle deceleration in the driving information is less than the preset deceleration threshold, and, determine whether the stroke change rate is lower than the preset change rate threshold, and, whether the current stroke exceeds the preset smooth stroke.

[0121] Specifically, if the following conditions are met simultaneously: 1. The vehicle deceleration in the driving information is less than the preset deceleration threshold; 2. The stroke change rate is lower than the preset change rate threshold; 3. The current stroke does not exceed the preset smooth stroke, it means that the vehicle is in a slow deceleration scenario and has just entered the braking force control phase from the pre-tightening establishment phase. Therefore, braking force smooth control can be performed to reduce the target clamping force determined by the stroke clamping force curve.

[0122] Exemplarily, the reduction amounts corresponding to each stroke and each deceleration can be pre-calibrated in advance, and then the reduction amount can be queried according to the current stroke and the vehicle deceleration. Subtract the reduction amount from the target clamping force to obtain a new target clamping force, and thus output the new target clamping force.

[0123] In one example, reducing the target clamping force includes:

[0124] Determine the current smoothing parameter based on the current stroke, the preset pre-tightening stroke, and the preset smoothing stroke; re-determine the new target clamping force according to the current smoothing parameter, the actual clamping force, and the target clamping force.

[0125] Among them, the preset smoothing stroke can be the maximum pedal stroke for smoothing control pre-calibrated. Specifically, the difference between the current stroke and the preset pre-tightening stroke can be calculated as the first difference, and the difference between the preset pre-tightening stroke and the preset smoothing stroke can be calculated as the second difference. Then, the proportion of the first difference in the second difference can be determined to obtain the current smoothing parameter, which can reflect the degree to which the current stroke approaches the maximum pedal stroke for smoothing control.

[0126] Furthermore, the first weight and the second weight can be determined according to the current smoothing parameter. For example, the current smoothing parameter is used as the first weight, and is used as the second weight. Through the first weight and the second weight, the target clamping force calculated at the current moment and the detected actual clamping force are weighted and fused to obtain the new target clamping force. As shown in the following formula:

[0127] ;

[0128] In the formula, is the new target clamping force, is the actual clamping force, is the target clamping force.

[0129] Through the above example, when the current stroke is equal to the preset pre-tightening stroke, the finally output target clamping force is equal to the detected actual clamping force. When the current stroke is equal to the preset smoothing stroke, the finally output target clamping force is equal to the target clamping force calculated through the curve slope, thus realizing the smooth transition of the clamping force from the preset pre-tightening stroke to the preset smoothing stroke, that is, realizing smooth control in the early stage of the braking force control stage.

[0130] Of course, if it is judged according to the driving information and the stroke information that the vehicle does not meet the preset smooth transition condition of the clamping force, it means that the vehicle is in a rapid deceleration scenario or has exceeded the preset smoothing stroke (that is, entered the later stage of the braking force control stage). At this time, the target clamping force calculated through the curve slope can be directly output.

[0131] By performing smooth control in the early stage of the braking force control stage, flexible transition can be achieved in a non-emergency state. While not affecting the responsiveness during emergency braking, it can effectively alleviate the sense of jump caused by the stage switch and improve the smoothness of the user's braking control.

[0132] In the embodiments of the present application, considering that the above-mentioned parameters such as the preset contact stroke, the preset pre-tightening stroke, the preset smooth stroke, and the preset pre-tightening force are related to the actual state of the vehicle EMB, a change in the actual state of the EMB may affect the braking effect. For example, the wear between the brake pads and the brake disc in the EMB may cause an increase in the mechanical clearance, or the thermal expansion may cause a change in the mechanical clearance. Therefore, the above parameters can also be adaptively updated according to the actual state of the EMB.

[0133] In some alternative embodiments, the method provided by the embodiments of the present application further includes:

[0134] Obtain the operation state information of the electro-mechanical braking system, and determine whether the vehicle meets the preset parameter adjustment condition according to the operation state information; if so, update at least one of the preset contact stroke, the preset pre-tightening stroke, and the preset pre-tightening force.

[0135] Among them, the operation state information may include the braking response times of the electro-mechanical braking system, the operation duration, the number of times of applying the limit clamping force, and the average temperature. The preset parameter adjustment condition may be that the wear degree reaches the set wear threshold or the average temperature reaches the set temperature threshold.

[0136] Specifically, the wear degree of the electro-mechanical braking system can be determined according to the braking response times, the operation duration, and the number of times of applying the limit clamping force in the operation state information. For example, weights can be set for the braking response times, the operation duration, and the number of times of applying the limit clamping force respectively, and the wear degree can be evaluated by a weighted method. Further, if the wear degree reaches the set wear threshold, it means that there is significant wear in the electro-mechanical braking system at this time, and the mechanical clearance may change. Therefore, it can be determined that the vehicle meets the preset parameter adjustment condition.

[0137] Alternatively, it can be determined whether the average temperature in the operation state information is greater than the preset temperature threshold. If so, it means that the average temperature of the electro-mechanical braking system rises at this time, and the mechanical clearance may change. Therefore, it can be determined that the vehicle meets the preset parameter adjustment condition.

[0138] Further, if the vehicle meets the preset parameter adjustment condition, at least one of the preset contact stroke, the preset pre-tightening stroke, and the preset pre-tightening force can be adjusted. In addition, parameters such as the preset smooth stroke can also be adjusted.

[0139] Through the above alternative embodiments, the preset contact stroke and other parameters can be dynamically optimized according to the operation state information of the electro-mechanical braking system. The optimized parameters can be used in the next control cycle, which can ensure the reliability of subsequent braking control.

[0140] Figure 2 is a control flow chart of an electro-mechanical braking system provided by the embodiments of the present application, as Figure 2As shown, first, system initialization can be performed, and historical calibration data (including preset pre-tightening force, preset contact stroke, preset pre-tightening stroke, etc.) and actuator status are input.

[0141] During the process of the user triggering the brake pedal, the clearance elimination stage can be entered first. The goal of this stage is to complete the contact between the brake pad and the brake disc at the preset contact stroke. The inputs include: current stroke, stroke change rate, actuator displacement, and the output is the target displacement.

[0142] After the current stroke reaches the preset contact stroke, the pre-tightening establishment stage can be entered. The goal of this stage is to reach the preset pre-tightening force at the preset pre-tightening stroke. The inputs include: actual clamping force, preset pre-tightening force; and the output is the clamping force command.

[0143] After the current stroke reaches the preset pre-tightening stroke, the braking force control stage can be entered. The goal of this stage is to output the corresponding target clamping force based on the curve slope, which can be divided into two processes. First is the main look-up table control. According to the input current stroke, curve slope, and actual clamping force, the output target clamping force is determined. Then there is the smoothing control. It can be judged whether the preset clamping force smoothing condition is satisfied according to the input current stroke, preset smoothing stroke, preset pre-tightening stroke, stroke change rate, and vehicle deceleration. If satisfied, the adjusted target clamping force is output.

[0144] During the completion of the braking response process, safety detection and feedback closed-loop can also be realized. The inputs include various sensor data (such as current stroke, actual clamping force, actuator status, etc.). The input can also include the current control status (stage and PID status, etc., PID refers to proportional-integral-derivative control). Based on the input, at the end of the pre-tightening establishment stage, an emergency supplement strategy can be triggered, and when an abnormality occurs in the braking force control stage (such as response lag, excessive clamping force deviation), the emergency braking mode is activated to perform abnormal alarm and generate an emergency braking signal. At the same time, the abnormal data can be recorded in the data log and fed back to the adaptive module.

[0145] In addition, during the braking response process, operation data recording and adaptive update can also be performed. The inputs include all data collected within each braking cycle, such as current stroke, stroke change rate, actual clamping force, etc. The data can be recorded in real time and stored in the database, and parameter self-learning update is performed according to discrete or online adaptive algorithms to update the look-up table curve, PID parameters, and feed-forward mapping parameters, etc.; and if it is found that the system changes dynamically (such as brake pad wear or temperature compensation), parameters such as preset pre-tightening force and preset contact stroke are adjusted in a timely manner. The optimized parameters can be used for the next control cycle, and the generated reports and logs can be used for system diagnosis and verification.

[0146] The above process significantly improves the response agility and smoothness of the braking system through phased adaptive control. During the clearance elimination phase and the pre-tightening establishment phase, feedforward control is used to complete mechanical clearance elimination in advance, so that the clamping force is fully established before the fixed switching point and the target value is maintained if necessary. Subsequently, during the braking force control phase, the subsequent clamping force is accurately controlled by looking up a table to ensure consistent dynamic response. At the same time, the introduced micro-transition smoothing can effectively alleviate the sudden change problem during the phase transition process, improve the driver's pedal feel and system smoothness, and the emergency supplement mechanism quickly makes up the clamping force when the pre-tightening is insufficient to ensure safe braking. The whole process not only improves the driving experience, reduces the braking delay, but also improves the robustness and stability of the system, is applicable to various operating conditions, and helps to achieve more refined and intelligent braking control.

[0147] Figure 3 FIG. 4 is a schematic structural diagram of a control device for an electromechanical braking system provided by an embodiment of the present application. The device includes a stroke acquisition module 310, a clearance elimination module 320, and a pre-tightening establishment module 330, where:

[0148] The stroke acquisition module 310 is configured to detect that the brake pedal in the vehicle is triggered, and acquire the stroke information of the brake pedal, where the stroke information includes the current stroke and the corresponding stroke change rate;

[0149] The clearance elimination module 320 is configured to, in response to the current stroke not exceeding a preset contact stroke, control the brake pad in the electromechanical braking system to move toward the brake disc based on the stroke information;

[0150] The pre-tightening establishment module 330 is configured to, in response to the current stroke being greater than the preset contact stroke and not exceeding a preset pre-tightening stroke, acquire the actual clamping force generated after the brake pad contacts the brake disc, and adjust the clamping force between the brake pad and the brake disc based on the stroke information when the actual clamping force does not reach the preset pre-tightening force.

[0151] On the basis of the above embodiments, optionally, the clearance elimination module 320 is specifically configured to:

[0152] Determine the target displacement of the brake pad based on the current stroke, the stroke change rate, and a pre-constructed displacement mapping function; control the movement of the brake pad according to the target displacement.

[0153] Based on the above embodiments, optionally, the gap elimination module 320 is further configured to obtain a preset fast contact interval close to the preset contact stroke; if the current stroke is within the preset fast contact interval, adjust the parameters in the displacement mapping function, and input the current stroke and the stroke change rate into the adjusted displacement mapping function to determine the target displacement of the brake block.

[0154] Based on the above embodiments, optionally, the preloading establishment module 330 is specifically configured to: determine the clamping force deviation between the preset preloading force and the actual clamping force, and the stroke difference between the current stroke and the preset preloading stroke; determine the current clamping force increment based on the stroke difference and the clamping force deviation; and adjust the clamping force between the brake block and the brake disc based on the current clamping force increment.

[0155] Based on the above embodiments, optionally, the preloading establishment module 330 is further configured to determine the estimated time for the brake pedal to reach the preset preloading stroke from the current stroke according to the stroke difference and the stroke change rate; if the estimated time is less than a preset time threshold, determine the emergency supplement rate of the clamping force according to the estimated time and the clamping force deviation; and determine the current clamping force increment according to the emergency supplement rate and the preset sampling time interval.

[0156] Based on the above embodiments, optionally, the device further includes a braking force control module, configured to, in response to the current stroke being greater than the preset preloading stroke, obtain the actual clamping force between the brake block and the brake disc; determine the target clamping force based on the actual clamping force, the stroke difference between the current stroke and the preset preloading stroke, and the slope of the pre-calibrated stroke-clamping force curve, and control the clamping force between the brake block and the brake disc according to the target clamping force.

[0157] Based on the above embodiments, optionally, the braking force control module is further configured to obtain the driving information of the vehicle; determine whether the vehicle meets the preset clamping force smooth transition condition based on the driving information and the stroke information, and if so, reduce the target clamping force;

[0158] wherein, the clamping force smooth transition condition includes: the vehicle deceleration in the driving information is less than a preset deceleration threshold, and, the stroke change rate is lower than a preset change rate threshold, and, the current stroke does not exceed a preset smooth stroke.

[0159] Based on the above embodiments, optionally, the braking force control module is further configured to determine a current smoothing parameter based on the current stroke, the preset pre-tightening stroke, and the preset smoothing stroke; and re-determine a new target clamping force according to the current smoothing parameter, the actual clamping force, and the target clamping force.

[0160] Based on the above embodiments, optionally, the device further includes a parameter update module, configured to obtain the operating state information of the electromechanical braking system, and determine whether the vehicle meets a preset parameter adjustment condition according to the operating state information; if so, update at least one of the preset contact stroke, the preset pre-tightening stroke, and the preset pre-tightening force.

[0161] The control device of the electromechanical braking system provided in the embodiments of the present application can execute the steps in the control method of the electromechanical braking system provided in the method embodiments of the present application, and the implementation steps and beneficial effects are not described herein again.

[0162] Figure 4 It is a schematic structural diagram of an electronic device provided in an embodiment of the present application. As Figure 4 shown, the electronic device 400 includes one or more processors 401 and a memory 402.

[0163] The processor 401 may be a central processing unit (CPU) or other form of processing unit with data processing capabilities and / or instruction execution capabilities, and may control other components in the electronic device 400 to perform desired functions.

[0164] The memory 402 may include one or more computer program products, and the computer program products may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may include, for example, random access memory (RAM) and / or cache memory, etc. The non-volatile memory may include, for example, read-only memory (ROM), hard disk, flash memory, etc. One or more computer program instructions may be stored on the computer-readable storage media, and the processor 401 may run the program instructions to implement the control method of the electromechanical braking system in any embodiment of the present application described above and / or other desired functions. Various contents such as initial external parameters and thresholds may also be stored in the computer-readable storage media.

[0165] In one example, the electronic device 400 may further include: an input device 403 and an output device 404, and these components are interconnected through a bus system and / or other forms of connection mechanisms (not shown). The input device 403 may include, for example, a keyboard, a mouse, and the like. The output device 404 may output various information to the outside, including warning prompt information, braking force, and the like. The output device 404 may include, for example, a display, a speaker, a printer, and a communication network and its connected remote output devices, and the like.

[0166] Of course, for simplicity, Figure 4 only some of the components related to the present application in the electronic device 400 are shown, and components such as a bus, an input / output interface, and the like are omitted. In addition, according to specific application scenarios, the electronic device 400 may further include any other appropriate components.

[0167] In addition to the above methods and devices, an embodiment of the present application may also be a computer program product, which includes computer program instructions, and when the computer program instructions are run by a processor, the processor is caused to execute the steps of the control method of the electromechanical braking system provided in any embodiment of the present application.

[0168] The computer program product may be written in any combination of one or more programming languages for programming code to perform the operations of the embodiments of the present application. The programming languages include object-oriented programming languages such as Java, C++, etc., and also include conventional procedural programming languages such as the "C" language or similar programming languages. The program code may be executed entirely on the user computing device, partially on the user device, executed as an independent software package, partially on the user computing device and partially on a remote computing device, or entirely on a remote computing device or server.

[0169] Furthermore, an embodiment of the present application may also be a computer-readable storage medium, on which computer program instructions are stored, and when the computer program instructions are run by a processor, the processor is caused to execute the steps of the control method of the electromechanical braking system provided in any embodiment of the present application.

[0170] The computer-readable storage medium may adopt any combination of one or more readable media. The readable media may be a readable signal medium or a readable storage medium. The readable storage medium may include, for example, but is not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination of the above. More specific examples (a non-exhaustive list) of the readable storage medium include: an electrical connection having one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0171] It should be noted that the terms used in this application are only for describing specific embodiments and do not limit the scope of this application. As shown in the specification and claims of this application, unless the context clearly indicates otherwise, words such as "a", "an", "one", and / or "the" are not specifically singular and may also include the plural. The term "comprising", "including", or any other variant thereof is intended to cover non-exclusive inclusion, such that a process, method, or device including a series of elements not only includes those elements but also includes other elements not explicitly listed, or also includes elements inherent to such a process, method, or device. Without further limitation, an element defined by the statement "including one..." does not exclude the existence of additional identical elements in the process, method, or device including the said element.

[0172] It should also be noted that the orientation or positional relationship indicated by terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation to this application. Unless otherwise clearly specified and defined, terms such as "installed", "connected", "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection, an electrical connection; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the internal communication of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0173] In this article, specific examples are used to illustrate the principle and implementation of this application. The description of the above embodiments is only for helping to understand the method and its core idea of this application. The above is only the preferred implementation mode of this application. It should be noted that due to the limited nature of literal expression and objectively infinite specific structures, for those of ordinary skill in the art in this technical field, without departing from the principle of this application, several improvements, retouches or changes can be made, or the above technical features can be combined in an appropriate manner; these improvements, retouches, changes or combinations, or directly applying the concept and technical solution of the invention to other occasions without improvement, should all be regarded as the protection scope of this application.

Claims

1. A control method for an electromechanical braking system, characterized in that, Including: When it is detected that the brake pedal in the vehicle is triggered, obtain the stroke information of the brake pedal, where the stroke information includes the current stroke and the corresponding stroke change rate; In response to the current stroke not exceeding a preset contact stroke, based on the stroke information, control the brake pads in the electromechanical braking system to move towards the brake disc according to a pre-constructed displacement mapping function; In response to the current stroke being greater than the preset contact stroke and not exceeding a preset pre-tightening stroke, obtain the actual clamping force generated after the brake pads contact the brake disc. When the actual clamping force does not reach the preset pre-tightening force, adjust the clamping force between the brake pads and the brake disc based on the stroke information; Controlling the brake pads in the electromechanical braking system to move towards the brake disc based on the stroke information includes: Obtain a preset fast contact interval close to the preset contact stroke; if the current stroke is within the preset fast contact interval, adjust the parameters in the pre-constructed displacement mapping function, and input the current stroke and the stroke change rate into the adjusted displacement mapping function to determine the target displacement of the brake pads; control the movement of the brake pads according to the target displacement.

2. The control method of the electromechanical braking system according to claim 1, characterized in that, Adjusting the clamping force between the brake pads and the brake disc based on the stroke information includes: Determine the clamping force deviation between the preset pre-tightening force and the actual clamping force, and the stroke difference between the current stroke and the preset pre-tightening stroke; Based on the stroke difference and the clamping force deviation, determine the current clamping force increment; Adjust the clamping force between the brake pads and the brake disc based on the current clamping force increment.

3. The control method of the electromechanical braking system according to claim 2, characterized in that, Determining the current clamping force increment based on the stroke difference and the clamping force deviation includes: According to the stroke difference and the stroke change rate, determine the estimated time for the brake pedal to reach the preset pre-tightening stroke from the current stroke; If the estimated time is less than a preset time threshold, determine the emergency supplement rate of the clamping force according to the estimated time and the clamping force deviation; Determine the current clamping force increment according to the emergency supplement rate and the preset sampling time interval.

4. The control method of the electro-mechanical braking system according to claim 1, characterized in that, The method further includes: In response to the current stroke being greater than the preset pre-tightening stroke, obtain the actual clamping force between the brake pads and the brake disc; Based on the actual clamping force, the stroke difference between the current stroke and the preset pre-tightening stroke, and the slope of the pre-calibrated stroke-clamping force curve, determine the target clamping force, and control the clamping force between the brake pads and the brake disc according to the target clamping force.

5. The control method of the electromechanical braking system according to claim 4, wherein Before controlling the clamping force between the brake pads and the brake disc according to the target clamping force, it further includes: Obtain the driving information of the vehicle; Based on the driving information and the stroke information, determine whether the vehicle meets a preset clamping force smooth transition condition. If so, reduce the target clamping force; Wherein, the clamping force smooth transition condition includes: the vehicle deceleration in the driving information is less than a preset deceleration threshold, and the stroke change rate is lower than a preset change rate threshold, and the current stroke does not exceed a preset smooth stroke.

6. The control method of the electromechanical braking system according to claim 5, characterized in that, Reducing the target clamping force includes: Determining a current smoothing parameter based on the current stroke, the preset pre-tightening stroke, and the preset smoothing stroke; Re-determining a new target clamping force according to the current smoothing parameter, the actual clamping force, and the target clamping force.

7. The control method of the electromechanical braking system according to claim 1, wherein The method further includes: Obtaining the operating state information of the electro-mechanical braking system, and determining whether the vehicle meets the preset parameter adjustment condition according to the operating state information; If so, updating at least one of the preset contact stroke, the preset pre-tightening stroke, and the preset pre-tightening force.

8. An electronic device, characterized in that, The electronic device includes: A processor and a memory; The processor is configured to execute the steps of the control method of the electro-mechanical braking system according to any one of claims 1 to 7 by calling the program or instructions stored in the memory.

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