Parking control method, parking control device and vehicle

Abstract

The invention discloses a parking control method, a parking control device and a vehicle. The parking control method comprises the steps that parking working condition information of the vehicle is obtained, and the calibrated clamping force of calipers to a brake disc is determined according to the parking working condition information; determining a calibrated motor rotation angle according to the system rigidity curve and the calibrated clamping force; the system rigidity curve represents the corresponding relation between the clamping force and the motor rotation angle; according to the system conversion model, calibrating a motor rotation angle to obtain a falling point of the pawl on the ratchet wheel, and determining an actual falling point of the pawl on the ratchet wheel based on a preset condition; the system conversion model is used for representing the corresponding relation between the falling position of the pawl on the ratchet wheel and the motor rotation angle; determining a motor rotation angle of an actual falling point according to the system conversion model, and taking the motor rotation angle as a target motor rotation angle; after the control motor rotates to the target motor rotation angle, the pawl is controlled to fall. According to the technical scheme, it is guaranteed that the actual clamping force meets the clamping force needed by parking, and the parking performance of a vehicle is improved.

Description

Technical Field

[0001] This invention relates to the field of parking control technology, and in particular to a parking control method, a parking control device, and a vehicle. Background Technology

[0002] With the development of the automotive industry, more and more vehicles are adopting electromechanical braking systems for parking braking. Among them, the core component of the electromechanical braking system is the electromechanical brake caliper, which generates clamping force through motor drive, achieving full electronic control and having advantages such as simple structure, fast response, and precise control.

[0003] Currently, vehicles using electromechanical braking systems typically determine the required clamping force during parking by first determining the required clamping force; then, based on this required clamping force, the motor's rotation angle is determined, and the motor is controlled to rotate to that angle, causing the pawl to drop and engage with the ratchet's teeth, preventing the ratchet from rotating in the opposite direction and achieving mechanical locking. However, there is a current issue where the pawl's position on the ratchet is not the final locking position, resulting in an actual clamping force lower than the required clamping force, thus affecting the vehicle's parking effectiveness. Summary of the Invention

[0004] This invention provides several embodiments of a parking control method, a parking control device, and a vehicle. At least one embodiment addresses the problem that the pawl's falling position on the ratchet is not the final locking position, resulting in the actual clamping force being less than the required clamping force, thus affecting the vehicle's parking performance.

[0005] According to one aspect of the present invention, a parking control method is provided, comprising:

[0006] Obtain the vehicle's parking condition information, and determine the caliper's calibrated clamping force on the brake disc based on the parking condition information;

[0007] The calibrated motor rotation angle is determined based on the system stiffness curve and the calibrated clamping force; wherein, the system stiffness curve characterizes the correspondence between the clamping force and the motor rotation angle.

[0008] The landing point of the pawl on the ratchet is obtained based on the system conversion model and the calibrated motor rotation angle, and the actual landing point of the pawl on the ratchet is determined based on preset conditions; the system conversion model is used to represent the correspondence between the landing position of the pawl on the ratchet and the motor rotation angle.

[0009] The motor rotation angle at the actual landing point is determined based on the system conversion model, and the motor rotation angle at the actual landing point is determined as the target motor rotation angle.

[0010] After the control motor rotates to the target motor angle, the pawl is controlled to fall.

[0011] Optionally, the preset conditions include: in the clamping rotation direction, the actual landing point is greater than or equal to half a tooth pitch of the landing point corresponding to the calibrated motor rotation angle; determining the actual landing point of the pawl on the ratchet based on the preset conditions includes:

[0012] Move the drop point corresponding to the calibrated motor rotation angle at least half a tooth pitch in the clamping rotation direction to determine the actual drop point of the pawl on the ratchet.

[0013] Optionally, the step of moving the drop point corresponding to the calibrated motor rotation angle at least half a tooth pitch in the clamping rotation direction to determine the actual drop point of the pawl on the ratchet includes:

[0014] Determine whether the point where the pawl lands on the ratchet under the specified motor rotation angle is a tooth groove;

[0015] If so, the tooth groove corresponding to the calibrated motor rotation angle is determined as the target locking tooth groove, and the target locking tooth groove is moved half a tooth pitch in the clamping rotation direction to determine the actual landing point;

[0016] If not, the tooth groove closest to the falling position corresponding to the calibrated motor rotation angle along the clamping rotation direction is determined as the target locking tooth groove, and the target locking tooth groove is moved half a tooth pitch in the clamping rotation direction to determine the actual falling point.

[0017] Optionally, after controlling the pawl to fall after the control motor rotates to the target motor's rotation angle, the method further includes:

[0018] Obtain locking status feedback information, and determine whether parking conditions are met based on the locking status feedback information;

[0019] If the conditions are met, then maintain the current state and complete the parking process;

[0020] If the conditions are not met, the actual drop point of the pawl on the ratchet is adjusted until parking is successful or until the locking is satisfied n times, where n is an integer greater than or equal to 2. The locking status feedback information includes at least one of the following: the actual motor rotation angle when the motor is stationary, the actual clamping force of the caliper, and the direction of the solenoid feedback current.

[0021] Optionally, the parking conditions include at least one of the following:

[0022] Whether the actual motor rotation angle when the motor is stationary is greater than or equal to the motor rotation angle corresponding to the target locking tooth groove;

[0023] Whether the difference between the target motor rotation angle and the actual motor rotation angle when the motor is stationary is greater than the set value and less than or equal to the angle corresponding to half a tooth pitch;

[0024] When the motor is stationary, is the actual clamping force of the caliper greater than or equal to the calibrated clamping force?

[0025] Is the direction of the solenoid feedback current the locking direction?

[0026] Optionally, the step of continuing to adjust the actual drop point of the pawl on the ratchet includes:

[0027] Move the current actual landing point one tooth pitch in the direction of the ratchet's clamping rotation to determine the adjusted actual landing point.

[0028] Optionally, when n equals 2, determining the actual landing point of the pawl on the ratchet based on preset conditions includes:

[0029] The first actual landing point of the pawl on the ratchet is determined based on preset conditions;

[0030] The step of determining the motor rotation angle of the actual landing point based on the system conversion model, and determining the motor rotation angle of the actual landing point as the target motor rotation angle, includes:

[0031] The motor rotation angle at the first actual landing point is determined based on the system conversion model, and the motor rotation angle at the first actual landing point is determined as the first target motor rotation angle.

[0032] After controlling the motor to rotate to the first target motor angle and then controlling the pawl to fall, the method further includes:

[0033] Obtain the first locking status feedback information, and determine whether the first locking meets the parking conditions based on the first locking status feedback information;

[0034] If the conditions are not met, the first actual landing point is moved one tooth pitch in the clamping rotation direction of the ratchet to determine the second actual landing point.

[0035] The motor rotation angle of the second actual landing point is determined according to the system conversion model, and the motor rotation angle of the second actual landing point is determined as the second target motor rotation angle;

[0036] After the control motor rotates to the second target motor angle, the pawl is controlled to fall to perform a second locking.

[0037] Optionally, after the control motor rotates to the second target motor angle and controls the pawl to fall for a second locking, the method further includes:

[0038] Obtain the second locking status feedback information, and determine whether the second locking meets the parking conditions based on the second locking status feedback information;

[0039] If the second locking condition is met, the parking mechanism is controlled to maintain the current state, parking is completed, and ratchet tooth missing fault information is generated and reported.

[0040] If the second locking does not meet the parking conditions, the parking is released, and pawl and / or solenoid fault information is generated and reported.

[0041] Optionally, before determining the calibrated motor rotation angle based on the system stiffness curve and the calibrated clamping force, the method further includes:

[0042] The initial stiffness curve of the system is obtained through offline calibration;

[0043] The correction model generates a correction amount for the initial stiffness curve based on the historical operating data of the parking mechanism during each ignition cycle of the vehicle.

[0044] The initial stiffness curve is updated based on the correction amount to obtain the system stiffness curve for the current ignition cycle.

[0045] According to another aspect of the present invention, a parking control device is provided, comprising:

[0046] The information acquisition module is used to acquire the vehicle's parking condition information and determine the caliper's calibrated clamping force on the brake disc based on the parking condition information.

[0047] The calibration angle determination module is used to determine the calibration motor angle based on the system stiffness curve and the calibration clamping force; wherein, the system stiffness curve represents the correspondence between the clamping force and the motor angle;

[0048] The landing point determination module is used to obtain the landing point of the pawl on the ratchet based on the system conversion model and the calibrated motor rotation angle, and to determine the actual landing point of the pawl on the ratchet based on preset conditions; the system conversion model is used to represent the correspondence between the landing position of the pawl on the ratchet and the motor rotation angle;

[0049] The target rotation angle determination module is used to determine the motor rotation angle of the actual landing point according to the system conversion model, and to determine the motor rotation angle of the actual landing point as the target motor rotation angle;

[0050] The control module is used to control the motor to rotate to the target motor angle and to control the pawl to fall.

[0051] According to another aspect of the present invention, a vehicle is provided that is parked using the parking control method described in any embodiment of the present invention.

[0052] The technical solution provided by this invention determines the calibrated motor angle based on parking condition information, obtains the drop point of the pawl on the ratchet at the calibrated motor angle based on the system conversion model, adjusts the drop point of the pawl on the ratchet based on preset conditions, and determines the adjusted drop point as the actual drop point; determines the motor angle of the actual drop point based on the system conversion model, and determines the motor angle of the actual drop point as the target motor angle; after controlling the motor to rotate to the target motor angle, controls the pawl to drop for parking, so that the actual clamping force of the caliper is greater than or equal to the calibrated clamping force determined based on the parking condition information, meets the parking requirements, and thus improves the parking performance of the vehicle.

[0053] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0054] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0055] Figure 1 This is a flowchart of a parking control method provided in an embodiment of the present invention;

[0056] Figure 2 This is a partial structural schematic diagram of an electromechanical braking system provided in an embodiment of the present invention;

[0057] Figure 3 yes Figure 2 A schematic diagram of the ratchet structure shown;

[0058] Figure 4 This is a schematic diagram of the falling state of a pawl on a ratchet, where the falling point is located in the critical region of the tooth tip, according to an embodiment of the present invention.

[0059] Figure 5 This is a schematic diagram of the falling state of a pawl on a ratchet, where the falling point is located in the tooth groove, according to an embodiment of the present invention.

[0060] Figure 6 This is a flowchart of another parking control method provided in an embodiment of the present invention;

[0061] Figure 7 This is a schematic diagram of a principle for determining the actual landing point provided by an embodiment of the present invention;

[0062] Figure 8This is another schematic diagram of determining the actual landing point provided by an embodiment of the present invention;

[0063] Figure 9 This is another schematic diagram of determining the actual landing point provided by an embodiment of the present invention;

[0064] Figure 10 This is a schematic diagram of the locking process when the pawl's landing point on the ratchet is the actual landing point, according to an embodiment of the present invention.

[0065] Figure 11 This is a flowchart of another parking control method provided in an embodiment of the present invention;

[0066] Figure 12 This is a flowchart of another parking control method provided in an embodiment of the present invention;

[0067] Figure 13 This is a schematic diagram illustrating the adjustment principle of the actual landing point provided in an embodiment of the present invention;

[0068] Figure 14 This is a structural block diagram of a parking control device provided in an embodiment of the present invention. Detailed Implementation

[0069] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0070] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0071] This invention provides a parking control method. Figure 1 This is a flowchart of a parking control method provided in an embodiment of the present invention, see reference. Figure 1 Parking control methods include:

[0072] S110. Obtain the vehicle's parking condition information and determine the caliper's calibrated clamping force on the brake disc based on the parking condition information.

[0073] Specifically, the core component of an electromechanical braking system is the electromechanical brake (EMB) caliper. The EMB caliper mainly consists of a motor module, a parking mechanism, a reduction mechanism, and a transmission mechanism. During service braking, the power output from the motor is reduced and amplified by the reduction mechanism before being transmitted to the transmission mechanism. The transmission mechanism converts the rotational motion into linear motion via a ball screw to push the piston cylinder. The piston cylinder pushes the brake pads to clamp the brake disc, completing the braking process. When parking is required, the necessary clamping force is first output according to the above service braking logic, and then the parking mechanism pushes the brake disc... Figure 2 The pawl 20 shown in the figure descends to lock the gear 10, completing the parking maneuver, and the motor is powered off. The caliper piston (not shown in the figure) is connected to the ratchet 10 through the transmission system, and the solenoid 30 drives the pawl 20 to lock or release the ratchet, thereby realizing the parking clamping or parking release action.

[0074] When the driver issues a parking request, the parking control device (e.g., controller) in the vehicle obtains the vehicle's parking condition information and determines the caliper's calibrated clamping force on the brake disc based on the parking condition information; wherein, the parking condition information includes, but is not limited to, one or more of the following: the vehicle's load, the road slope when the vehicle is parked, the temperature of the brake disc at the time of parking, and the caliper's working state.

[0075] Regarding the vehicle's overall load, the greater the load, the greater the clamping force required; conversely, the smaller the load, the greater the clamping force required. Regarding the road slope when the vehicle is parked, the steeper the slope, the greater the clamping force required; the gentler the slope, the less the clamping force required. Regarding the brake disc temperature, since the brake disc temperature affects both the coefficient of friction and the system's coefficient of expansion, different temperatures require different clamping forces; the higher the brake disc temperature, the greater the required clamping force. Regarding the caliper's working condition, typically, a vehicle is parked using two or four calipers working together. If one or more calipers fail, the remaining working calipers need to increase the clamping force to maintain the vehicle's parking capability.

[0076] After obtaining parking condition information that characterizes the vehicle's current operating condition, a pre-stored mapping relationship can be queried or processed through a calculation model based on this information to determine an initial target clamping force value that matches the current vehicle state. This initial target clamping force value is the calibrated clamping force. By determining the calibrated clamping force of the caliper on the brake disc based on the parking condition information, the clamping force required for parking can be dynamically and accurately determined according to the vehicle's real-time state, thereby improving the vehicle's parking performance.

[0077] S120. Determine the calibrated motor rotation angle based on the system stiffness curve and the calibrated clamping force; wherein, the system stiffness curve characterizes the correspondence between the clamping force and the motor rotation angle.

[0078] Specifically, in an electromechanical braking system, a rotating motor drives a transmission mechanism (such as a screw and nut) to convert rotational motion into linear motion of the brake pads in the caliper towards the brake disc, thereby generating a clamping force on the brake disc. There is a non-linear relationship between the clamping force and the motor rotation angle, which is primarily determined by the mechanical stiffness of the entire transmission chain (i.e., system stiffness). This system stiffness includes various factors such as the elastic deformation of transmission components, clearances, and friction. The stiffness curve characterizes the mapping relationship between the clamping force applied to the brake disc and the motor rotation angle. Therefore, after determining the calibrated clamping force, the motor rotation angle corresponding to the calibrated clamping force can be determined based on the system stiffness curve, i.e., the calibrated motor rotation angle.

[0079] S130. Based on the system conversion model and the calibrated motor rotation angle, the landing point of the pawl on the ratchet is obtained, and the actual landing point of the pawl on the ratchet is determined based on preset conditions; the system conversion model is used to represent the correspondence between the landing position of the pawl on the ratchet and the motor rotation angle.

[0080] Specifically, the motor's rotation speed is reduced and the torque is increased through a reduction gear set. The increased torque is transmitted to the ratchet 10, so the motor directly drives the ratchet 10 to rotate. In one embodiment or implementation scenario, the rotational speed of the ratchet 10 is usually not equal to the rotational speed of the motor; there is a preset speed ratio between the two. Furthermore, the ratchet 10 and the motor are rigidly connected. It can be assumed that once assembled, their relative positions will not change throughout the product's lifecycle, thus the correspondence between the ratchet 10 position and the motor rotation angle is fixed. However, since the position of the motor shaft is random during ratchet 10 assembly, the corresponding motor rotation angle is also random. Therefore, the correspondence between the ratchet 10 position and the motor rotation angle may be the same or different in different products. For example, in product A, the motor angle corresponding to the first tooth tip a of the gear rotating to the lower position of the pawl 20 is +5 degrees, while in product B, the motor angle corresponding to the first tooth tip a of the gear rotating to the lower position of the pawl 20 is +7 degrees.

[0081] The system conversion model represents the correspondence between the drop position of the pawl 20 on the ratchet 10 and the motor rotation angle. The correspondence between the position of the ratchet 10 and the motor rotation angle in each product can be obtained through offline calibration, thus obtaining the system conversion model. Therefore, the system conversion model can be used to obtain the drop point of the pawl 20 on the ratchet 10 at a certain motor rotation angle; it can also be used to determine the corresponding motor rotation angle based on the drop point of the pawl 20 on the ratchet 10. In this embodiment of the invention, after obtaining the calibrated motor rotation angle, the drop point of the pawl 20 on the ratchet 10 corresponding to the calibrated motor rotation angle is obtained through the system conversion model. Further, refer to... Figure 3 The ratchet 10 includes multiple alternately arranged tooth tips a and tooth grooves b. The system conversion model can specifically be used to represent the correspondence between each gear a and each tooth groove b and the motor rotation angle.

[0082] The position of the pawl 20 during parking control is crucial. (Reference) Figure 4 If the landing point of pawl 20 is too close to the tip of the next tooth a, it will cause ratchet 10 to retract excessively (ratchet 10 rotates too much in the release rotation direction x), reducing the clamping force; see reference. Figure 5 If the landing point of the pawl 20 is too close to the tooth groove b, the frictional force at the contact point will hinder its descent, preventing the pawl 20 from falling completely. This can cause vibrations in the system, potentially dislodging the pawl 20 from the ratchet 10. After obtaining the landing point of the pawl 20 on the ratchet 10 at the calibrated motor rotation angle, the landing point of the pawl 20 on the ratchet 10 is adjusted based on preset conditions to determine the actual landing point. This ensures that the actual landing point is offset from both the tooth tip a and the tooth groove b, while maintaining a clamping force greater than or equal to the calibrated clamping force after the pawl 20 reaches the actual landing point.

[0083] S140. Determine the motor rotation angle at the actual landing point based on the system conversion model, and set the motor rotation angle at the actual landing point as the target motor rotation angle.

[0084] S150: Control the motor to rotate to the target motor angle, then control the pawl to drop.

[0085] Specifically, the motor rotation angle of the actual landing point is determined according to the system conversion model, and the motor rotation angle of the actual landing point is determined as the target motor rotation angle; the motor is controlled to rotate to the target motor rotation angle, so that the ratchet 10 rotates to the target position, that is, after the pawl 20 is controlled to fall, the landing point of the pawl 20 on the ratchet 10 is the determined actual landing point.

[0086] The parking control method provided by this invention determines the calibration motor angle based on parking condition information, obtains the drop point of the pawl 20 on the ratchet 10 at the calibration motor angle based on the system conversion model, and adjusts the drop point of the pawl 20 on the ratchet 10 based on preset conditions, and determines the adjusted drop point as the actual drop point; determines the motor angle of the actual drop point based on the system conversion model, and determines the motor angle of the actual drop point as the target motor angle; after controlling the motor to rotate to the target motor angle, controls the pawl 20 to drop to perform the parking action, so that the actual drop point is offset from the position of tooth tip a and the position of tooth groove b, while ensuring that the actual clamping force of the caliper is greater than or equal to the calibration clamping force determined based on the parking condition information, thus meeting the parking requirements and improving the parking performance of the vehicle.

[0087] Based on the above embodiments, optionally, the preset conditions include: in the clamping rotation direction, the actual drop point is greater than or equal to half a tooth pitch of the drop point corresponding to the calibrated motor rotation angle. Figure 6 This is a flowchart of another parking control method provided in an embodiment of the present invention, see reference. Figure 6 Parking control methods include:

[0088] S210. Obtain the vehicle's parking condition information and determine the caliper's calibrated clamping force on the brake disc based on the parking condition information.

[0089] S220. Determine the calibrated motor rotation angle based on the system stiffness curve and the calibrated clamping force; wherein, the system stiffness curve characterizes the correspondence between the clamping force and the motor rotation angle.

[0090] S230. Based on the system conversion model, calibrate the motor rotation angle to obtain the drop point of the pawl on the ratchet; the system conversion model is used to represent the correspondence between the drop position of the pawl on the ratchet and the motor rotation angle.

[0091] S240. Move the drop point corresponding to the calibrated motor rotation angle at least half a tooth pitch in the clamping rotation direction to determine the actual drop point of the pawl on the ratchet.

[0092] S250. Determine the motor rotation angle at the actual landing point based on the system conversion model, and set the motor rotation angle at the actual landing point as the target motor rotation angle.

[0093] S260: Control the motor to rotate to the target motor angle, then control the pawl to fall.

[0094] In the parking control method provided by this invention, the step of determining the actual landing point of the pawl 20 on the ratchet 10 based on preset conditions includes: moving the landing point corresponding to the calibrated motor rotation angle at least half a tooth pitch in the clamping rotation direction to determine the actual landing point of the pawl 20 on the ratchet 10. The technical solution provided by this invention, by moving the landing point corresponding to the calibrated motor rotation angle at least half a tooth pitch in the clamping rotation direction to determine the actual landing point of the pawl 20 on the ratchet 10, ensures that when the pawl 20's landing action occurs, the ratchet 10 has already rotated at least half a tooth pitch relative to the calibrated position, causing the brake disc to be further clamped, generating a clamping force slightly higher than the calibrated clamping force (initial target clamping force), i.e., generating a clamping force increment higher than the calibrated clamping force. This increment is designed to create a "safety redundancy": when the pawl 20 descends, even if the ratchet 10 retracts slightly due to insufficient reverse friction in the transmission chain, this clamping force increment can ensure that the residual clamping force is not less than the calibrated clamping force, thereby effectively compensating for the clamping force loss caused by the retraction and enhancing the reliability of locking.

[0095] Additionally, if the pawl 20 corresponding to the calibrated motor rotation angle falls at the tooth groove b (e.g.) Figure 5 If the drop point corresponding to the calibrated motor rotation angle is moved at least half a tooth pitch in the clamping rotation direction, it can avoid tooth groove b, thus facilitating the drop of pawl 20. If the drop point of the pawl corresponding to the calibrated motor rotation angle is located at the front end of the next tooth tip (e.g. Figure 4 If the pawl 20 falls into the next tooth groove area, the drop point corresponding to the calibrated motor rotation angle will be moved at least half a tooth pitch in the clamping rotation direction. This prevents the pawl 20 from falling back too much and causing the clamping force to decrease.

[0096] Furthermore, step S240, which moves the drop point corresponding to the calibrated motor rotation angle at least half a tooth pitch in the clamping rotation direction to determine the actual drop point of the pawl on the ratchet, specifically includes:

[0097] Determine whether the drop point of the pawl 20 on the ratchet 10 at the calibrated motor rotation angle is the tooth groove b;

[0098] If so, then the tooth groove b corresponding to the calibrated motor rotation angle is determined as the target locking tooth groove, and the target locking tooth groove is moved half a tooth pitch in the clamping rotation direction to determine the actual landing point;

[0099] If not, the tooth groove b closest to the falling position corresponding to the calibrated motor rotation angle along the clamping rotation direction is determined as the target locking tooth groove, and the target locking tooth groove is moved half a tooth pitch in the clamping rotation direction to determine the actual falling point.

[0100] Specifically, the target locking tooth groove can be understood as the groove b of the pawl 20 that finally engages after the pawl 20 has landed at the actual landing point. The clamping force corresponding to the target locking tooth groove should be greater than or equal to the calibrated clamping force. In determining the actual landing point, refer to... Figure 7 If the landing point QL of the pawl 20 on the ratchet 10 at the calibrated motor rotation angle is tooth groove b, and the pawl 20 is locked at the position of tooth groove b, the clamping force of the caliper on the brake disc is equal to the calibrated clamping force determined based on the parking condition information. This tooth groove b is determined as the target locking bm, and the target locking tooth groove bm is moved half a tooth pitch in the clamping rotation direction to determine the actual landing point QX. This allows the tooth groove b to be offset, avoiding the problem of being hindered by the frictional force at the contact point during the landing process when the landing point of the ratchet 10 is tooth groove b. In addition, since the landing point of the pawl 20 on the ratchet 10 is this actual landing point QX, even if the ratchet 10 retracts after the pawl 20 lands, the minimum clamping force can still achieve the effect of the calibrated clamping force.

[0101] In determining the actual landing point, if the landing point of the pawl 20 on the ratchet 10 at the calibrated motor rotation angle is not the tooth groove b, refer to... Figure 8 The point QL where the pawl 20 lands on the ratchet 10 at the calibrated motor rotation angle is located between the tooth groove b and the next tooth tip a, or, refer to Figure 9 If the landing point QL of the pawl 20 on the ratchet 10 at the specified motor rotation angle is located at the next tooth tip a, then the tooth groove b (the next tooth groove b) closest to the landing position corresponding to the specified motor rotation angle along the clamping rotation direction is determined as the target locking tooth groove bm. The clamping force corresponding to this target locking tooth groove bm is greater than the specified clamping force. Moving this target locking tooth groove bm half a tooth pitch in the clamping rotation direction determines the actual landing point QX. This can offset the tooth groove b, avoiding the problem of being hindered by contact point friction during the landing process when the landing point of the ratchet 10 is tooth groove b. In addition, since the landing point of the pawl 20 on the ratchet 10 is this actual landing point QX, even if the ratchet 10 retracts after the pawl 20 lands, the minimum clamping force can still be greater than the specified clamping force.

[0102] Additionally, refer to Figure 10 Move the target locking tooth groove bm half a tooth pitch in the clamping rotation direction to determine the actual landing point QX, so that the actual landing point QX is exactly located in the middle area between the target locking tooth groove bm and the next tooth tip a, neither too close to the target locking tooth groove bm nor too close to the tooth tip a, which is conducive to the landing of the pawl 20.

[0103] Figure 11 This is a flowchart of another parking control method provided in an embodiment of the present invention, see reference. Figure 11 Parking control methods include:

[0104] S310. Obtain the vehicle's parking condition information and determine the caliper's calibrated clamping force on the brake disc based on the parking condition information.

[0105] S320. Determine the calibrated motor rotation angle based on the system stiffness curve and the calibrated clamping force; wherein, the system stiffness curve characterizes the correspondence between the clamping force and the motor rotation angle.

[0106] S330. Based on the system conversion model and the calibrated motor rotation angle, the landing point of the pawl on the ratchet is obtained, and the actual landing point of the pawl on the ratchet is determined based on preset conditions; the system conversion model is used to represent the correspondence between the landing position of the pawl on the ratchet and the motor rotation angle.

[0107] S340. Determine the motor rotation angle at the actual landing point based on the system conversion model, and set the motor rotation angle at the actual landing point as the target motor rotation angle.

[0108] S350: Control the motor to rotate to the target motor angle, then control the pawl to drop.

[0109] S360. Obtain locking status feedback information. Determine whether the parking conditions are met based on the locking status feedback information. If yes, proceed to step S370; otherwise, proceed to step S380.

[0110] S370, Maintain the current state and complete parking.

[0111] S380. Continue to adjust the actual drop point of the pawl on the ratchet until parking is successful or until the locking is satisfied n times, where n is an integer greater than or equal to 2.

[0112] In the parking control method provided by this embodiment of the invention, after controlling the motor to rotate to the target motor angle and controlling the pawl 20 to fall, the method further includes: obtaining locking status feedback information, and determining whether the parking conditions are met based on the locking status feedback information; if met, maintaining the current state to complete parking; if not met, continuing to adjust the actual landing point QX of the pawl 20 on the ratchet 10 until parking is successful or until n locking attempts are completed, where n is an integer greater than or equal to 2. The technical solution provided by this embodiment of the invention, when the parking conditions are not met after controlling the motor to rotate to the target motor angle and controlling the pawl 20 to fall, allows for re-parking by continuing to adjust the actual landing point QX of the pawl 20 on the ratchet 10, thus avoiding problems such as missing teeth on the gears affecting the parking effect or even preventing parking.

[0113] The locking status feedback information includes at least one of the following: the actual motor rotation angle when the motor is stationary, the actual clamping force of the caliper, and the direction of the solenoid feedback current. The actual motor rotation angle when the motor is stationary can be obtained using a motor position sensor (such as a rotary transformer or Hall encoder). The actual clamping force of the caliper when the motor is stationary can be obtained using a pressure sensor or a clamping force model estimated based on the motor current. The direction of the solenoid feedback current can be determined by monitoring the current of the solenoid valve or motor driving the pawl 20. The current direction is used to determine whether the command is "extend" or "retract." For example, a positive current represents the pawl 20 extending and falling, while a negative current represents the pawl 20 retracting.

[0114] Furthermore, parking conditions include at least one of the following:

[0115] Condition A1: Whether the actual motor rotation angle when the motor is stationary is greater than or equal to the motor rotation angle corresponding to the target locking tooth slot;

[0116] Condition A2: Whether the difference between the target motor rotation angle and the actual motor rotation angle when the motor is stationary is greater than the set value and less than or equal to the angle corresponding to half a tooth pitch; the set value is set according to actual needs, for example, it can be 0;

[0117] Condition A3: When the motor is stationary, is the actual clamping force of the caliper greater than or equal to the rated clamping force?

[0118] Condition A4: Is the direction of the solenoid feedback current the locking direction?

[0119] In one embodiment of the present invention, determining whether the current locking meets the parking conditions based on the locking status feedback information includes: judging whether the actual motor rotation angle when the motor is stationary is greater than or equal to the motor rotation angle corresponding to the target locking tooth slot; if yes, then the current locking meets the parking conditions; if no, then the current locking does not meet the parking conditions. In another embodiment of the present invention, determining whether the current locking meets the parking conditions based on the locking status feedback information includes: judging whether the difference between the target motor rotation angle and the actual motor rotation angle when the motor is stationary is greater than 0 and less than or equal to the angle corresponding to half a tooth pitch; if yes, then the current locking meets the parking conditions; if no, then the current locking does not meet the parking conditions. In another embodiment of the present invention, determining whether the current locking meets the parking conditions based on the locking status feedback information includes: judging whether the actual clamping force of the caliper when the motor is stationary is greater than or equal to the calibrated clamping force; if yes, then the current locking meets the parking conditions; if no, then the current locking does not meet the parking conditions. In another embodiment of the present invention, determining whether the current locking meets the parking conditions based on the locking status feedback information includes: determining whether the direction of the solenoid feedback current is the locking direction; if yes, then the current locking meets the parking conditions; if no, then the current locking does not meet the parking conditions. In another embodiment of the present invention, determining whether the current locking meets the parking conditions based on the locking status feedback information includes: determining whether the actual motor rotation angle when the motor is stationary is greater than or equal to the motor rotation angle corresponding to the target locking tooth slot, and determining whether the difference between the target motor rotation angle and the actual motor rotation angle when the motor is stationary is greater than 0 and less than or equal to the angle corresponding to half a tooth pitch, and determining whether the actual clamping force of the caliper when the motor is stationary is greater than or equal to the calibrated clamping force; if all are yes, then the current locking meets the parking conditions; if at least one is no, then the current locking does not meet the parking conditions.

[0120] The embodiments can be used as conditions individually or in combination.

[0121] Preferably, the locking status feedback information includes at least two of the following: the actual motor rotation angle when the motor is stationary, the actual clamping force of the caliper, and the direction of the solenoid feedback current. By comprehensively judging at least two interrelated physical parameters, cross-verification of multiple pieces of information can be achieved, thereby enabling highly reliable confirmation of the locking status and accurate fault diagnosis.

[0122] Based on the above embodiments, optionally, step S380, which involves further adjusting the actual landing point of the pawl on the ratchet, includes:

[0123] Move the current actual landing point QX one tooth pitch in the clamping rotation direction of ratchet 10 to determine the adjusted actual landing point QX.

[0124] Specifically, by shifting the current actual landing point QX one tooth pitch in the clamping rotation direction of the ratchet 10, the adjusted actual landing point QX is determined. This ensures that the adjusted actual landing point QX is offset from the next tooth groove b, thus avoiding the problem of being hindered by contact point friction during the descent. Furthermore, having the pawl 20's landing point on the ratchet 10 as this adjusted actual landing point QX further increases the minimum clamping force.

[0125] The actual drop point QX of the pawl 20 on the ratchet 10 is adjusted at least once until parking is successful or until n locking cycles are met. This avoids the problem of parking failure due to one or more missing teeth on the gear. It also determines the specific location of the missing teeth and reports the missing tooth fault information (e.g., the number and specific location of the missing teeth) after successful parking. If the parking condition is still not met after n locking cycles, fault information of the pawl 20 and / or solenoid is generated and reported to provide a fault reminder.

[0126] Let's take an example of n equal to 2 to illustrate this. Figure 12 This is a flowchart of another parking control method provided in an embodiment of the present invention, see reference. Figure 12 Parking control methods include:

[0127] S410. Obtain the vehicle's parking condition information and determine the caliper's calibrated clamping force on the brake disc based on the parking condition information.

[0128] S420. Determine the calibrated motor rotation angle based on the system stiffness curve and the calibrated clamping force; wherein, the system stiffness curve characterizes the correspondence between the clamping force and the motor rotation angle.

[0129] S430. Based on the system conversion model and the calibrated motor rotation angle, the landing point of the pawl on the ratchet is obtained, and the first actual landing point of the pawl on the ratchet is determined based on preset conditions; the system conversion model is used to represent the correspondence between the landing position of the pawl on the ratchet and the motor rotation angle.

[0130] S440. Determine the motor rotation angle of the first actual landing point based on the system conversion model, and set the motor rotation angle of the first actual landing point as the first target motor rotation angle.

[0131] S450: After the control motor rotates to the first target motor angle, control the pawl to fall and perform the first locking.

[0132] S460. Obtain the first locking status feedback information. Determine whether the first locking meets the parking conditions based on the first locking status feedback information. If yes, proceed to step S470; otherwise, proceed to step S480.

[0133] S470, Maintain the current state and complete parking.

[0134] S480. Move the first actual landing point one tooth pitch in the direction of the ratchet's clamping rotation to determine the second actual landing point.

[0135] S490. Determine the motor rotation angle of the second actual landing point based on the system conversion model, and set the motor rotation angle of the second actual landing point as the second target motor rotation angle.

[0136] S4100: After the control motor rotates to the second target motor angle, control the pawl to drop to perform a second locking.

[0137] S4110. Obtain the second locking status feedback information. Determine whether the second locking meets the parking conditions based on the second locking status feedback information. If yes, proceed to step S4120; otherwise, proceed to step S4130.

[0138] S4120: Maintain the current state to complete parking, and generate and report ratchet tooth loss fault information.

[0139] S4130, release the parking brake and generate and report pawl and / or solenoid fault information.

[0140] In this embodiment of the invention, reference Figure 13The actual landing point includes a first actual landing point QX1 and a second actual landing point QX2, where the second actual landing point QX2 is an adjusted actual landing point based on the first actual landing point QX1. The target motor angle includes a first target angle corresponding to the first actual landing point QX1 and a second target angle corresponding to the second actual landing point QX2. Step S130, determining the actual landing point of the pawl 20 on the ratchet 10 based on preset conditions, includes: determining the first actual landing point QX1 of the pawl 20 on the ratchet 10 based on preset conditions. Step S140, determining the motor angle of the actual landing point according to the system conversion model and defining the motor angle of the actual landing point as the target motor angle, includes: determining the motor angle of the first actual landing point QX1 according to the system conversion model and defining the motor angle of the first actual landing point QX1 as the first target motor angle. Step S150 involves controlling the motor to rotate to the target motor angle and then controlling the pawl 20 to fall, including controlling the motor to rotate to the first target motor angle and then controlling the pawl 20 to fall for the first locking. After controlling the motor to rotate to the first target motor angle and then controlling the pawl 20 to fall, the steps further include: obtaining the first locking status feedback information, determining whether the first locking meets the parking conditions based on the first locking status feedback information; if not, moving the first actual landing point QX1 one tooth pitch in the clamping rotation direction of the ratchet 10 to determine the second actual landing point QX2; determining the motor angle of the second actual landing point QX2 according to the system conversion model, and determining the motor angle of the second actual landing point QX2 as the second target motor angle; controlling the motor to rotate to the second target motor angle and then controlling the pawl 20 to fall for the second locking. Among them, the target locking groove corresponding to the first actual landing point QX1 after the pawl 20 falls is the first target locking groove bm1, and the target locking groove corresponding to the second actual landing point QX2 after the pawl 20 falls is the second target locking groove bm2.

[0141] After controlling the motor to rotate to the second target motor angle and controlling the pawl 20 to fall for a second locking, the process also includes: obtaining feedback information on the second locking status, determining whether the second locking meets the parking conditions based on the feedback information; if the second locking meets the parking conditions, controlling the parking mechanism to maintain the current state, completing parking, and generating and reporting ratchet 10 missing tooth fault information; if the second locking does not meet the parking conditions, releasing parking, and generating and reporting pawl 20 and / or solenoid fault information.

[0142] In the above embodiments, the step of determining the second target motor angle occurs after determining that the first locking does not meet the parking conditions. In another embodiment of the present invention, after determining the first actual landing point QX1 of the pawl 20 on the ratchet 10 based on preset conditions, the first actual landing point QX1 can be moved one tooth pitch in the clamping rotation direction of the ratchet 10 to determine the second actual landing point QX2, and then the second target motor angle can be determined. That is, the step of determining the second target motor angle occurs after the step of determining the first actual landing point QX1 of the pawl 20 on the ratchet 10 based on preset conditions. By adjusting the order of the above steps, after determining that the first locking does not meet the parking conditions, the second target motor angle can be directly obtained, and the control motor can be controlled to rotate to the second target motor angle before the pawl 20 is controlled to fall for a second locking.

[0143] Based on the above embodiments, optionally, before determining the calibrated motor rotation angle according to the system stiffness curve and the calibrated clamping force in steps S120, S220, S320, and S420, the following steps are also included:

[0144] The initial stiffness curve of the system is obtained through offline calibration;

[0145] The correction model generates a correction amount for the initial stiffness curve based on the historical operating data of the parking mechanism during each ignition cycle of the vehicle.

[0146] The initial stiffness curve is updated based on the correction amount to obtain the system stiffness curve for the current ignition cycle.

[0147] Specifically, after the vehicle is manufactured and rolls off the production line, system calibration is performed to obtain the initial stiffness curve. The process may include: placing the vehicle on a braking system test bench and driving the parking motor to execute a series of predetermined loading-unloading cycles; measuring the clamping force output by the calipers in real time using a high-precision force sensor and simultaneously recording the corresponding motor rotation angle; collecting multiple sets of clamping force and motor rotation angle data pairs, and obtaining the initial stiffness curve through a curve fitting algorithm. During each ignition cycle of the vehicle, using historical operating data of the parking mechanism, the correction amount for the initial stiffness curve is calculated through a correction model. Based on the calculated correction amount, the initial stiffness curve is updated to generate a real-time stiffness curve specific to the current ignition cycle, i.e., the system stiffness curve. The technical solution provided by this invention, by obtaining the correction amount through self-learning and correcting the initial stiffness curve, can compensate for the system stiffness decay caused by component wear, temperature changes, etc., thereby maintaining parking force control accuracy throughout the entire vehicle lifecycle; reducing warranty repairs and component replacements due to accuracy drift, extending system lifespan, and reducing costs.

[0148] This invention also provides a parking control device. Figure 14This is a structural block diagram of a parking control device provided in an embodiment of the present invention, with reference to... Figure 14 The parking control device includes:

[0149] The information acquisition module 100 is used to acquire the vehicle's parking condition information and determine the caliper's calibrated clamping force on the brake disc based on the parking condition information.

[0150] The calibration angle determination module 200 is used to determine the calibration motor angle based on the system stiffness curve and the calibration clamping force; wherein, the system stiffness curve represents the correspondence between the clamping force and the motor angle.

[0151] The landing point determination module 300 is used to obtain the landing point of the pawl on the ratchet based on the system conversion model and the calibrated motor rotation angle, and to determine the actual landing point of the pawl on the ratchet based on preset conditions; the system conversion model is used to represent the correspondence between the landing position of the pawl on the ratchet and the motor rotation angle;

[0152] The target rotation angle determination module 400 is used to determine the motor rotation angle at the actual landing point based on the system conversion model, and to determine the motor rotation angle at the actual landing point as the target motor rotation angle;

[0153] The control module 500 is used to control the motor to rotate to the target motor angle and control the pawl to fall.

[0154] Optionally, the parking control device also includes a feedback information acquisition module, which acquires locking status feedback information and determines whether parking conditions are met based on the locking status feedback information. The locking status feedback information includes at least one of the following: the actual motor rotation angle when the motor is stationary, the actual clamping force of the caliper, and the direction of the solenoid feedback current. The landing point determination module 300 is further used to, if the locking status feedback information does not meet parking conditions, shift the current actual landing point one tooth pitch in the clamping rotation direction of the ratchet, thus determining the adjusted actual landing point.

[0155] The parking control device provided in the embodiments of the present invention can execute the parking control method provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the method.

[0156] This invention also provides a vehicle that is parked using the parking control method described in any embodiment of this invention. It has the same beneficial effects, which will not be repeated here.

[0157] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A parking control method characterized by, The method comprises the following steps: acquiring parking working condition information of a vehicle, and determining a calibration clamping force of a caliper on a brake disc according to the parking working condition information; determining a calibration motor rotation angle according to a system stiffness curve and the calibration clamping force, wherein the system stiffness curve represents a corresponding relationship between the clamping force and the motor rotation angle; obtaining a falling point of a pawl on a ratchet wheel according to a system conversion model and the calibration motor rotation angle, and determining an actual falling point of the pawl on the ratchet wheel based on a preset condition, wherein the system conversion model is used to represent a corresponding relationship between the falling position of the pawl on the ratchet wheel and the motor rotation angle; determining a motor rotation angle of the actual falling point according to the system conversion model, and determining the motor rotation angle of the actual falling point as a target motor rotation angle; controlling the pawl to fall after the motor is controlled to rotate to the target motor rotation angle.

2. The parking control method according to claim 1, characterized by, The preset condition comprises that, in a clamping rotation direction, the actual falling point is greater than or equal to a falling point corresponding to the calibration motor rotation angle by at least half a tooth pitch, and the actual falling point of the pawl on the ratchet wheel is determined based on the preset condition, which comprises: moving the falling point corresponding to the calibration motor rotation angle to the clamping rotation direction by at least half a tooth pitch to determine the actual falling point of the pawl on the ratchet wheel.

3. The parking control method according to claim 2, characterized by, The moving of the falling point corresponding to the calibration motor rotation angle to the clamping rotation direction by at least half a tooth pitch to determine the actual falling point of the pawl on the ratchet wheel comprises: determining whether the falling point of the pawl on the ratchet wheel at the calibration motor rotation angle is a tooth groove; if yes, determining a target locking tooth groove as a tooth groove corresponding to the calibration motor rotation angle, and moving the target locking tooth groove to the clamping rotation direction by half a tooth pitch to determine the actual falling point; if no, determining a target locking tooth groove as a tooth groove closest to the falling position corresponding to the calibration motor rotation angle in the clamping rotation direction, and moving the target locking tooth groove to the clamping rotation direction by half a tooth pitch to determine the actual falling point.

4. The parking control method according to claim 1, characterized by, After the controlling of the pawl to fall after the motor is controlled to rotate to the target motor rotation angle, the method further comprises the following steps: acquiring locking state feedback information, and determining whether a parking condition is met according to the locking state feedback information; if yes, maintaining a current state to complete parking; if no, continuously adjusting the actual falling point of the pawl on the ratchet wheel until parking is successful or until n times of locking are met, wherein n is an integer greater than or equal to 2, and the locking state feedback information comprises at least one of an actual motor rotation angle when the motor is at rest, an actual clamping force of the caliper, and a direction of solenoid feedback current.

5. The parking control method according to claim 4, characterized by, The parking condition comprises at least one of the following: whether the actual motor rotation angle when the motor is at rest is greater than or equal to a motor rotation angle corresponding to the target locking tooth groove; whether a difference between the target motor rotation angle and the actual motor rotation angle when the motor is at rest is greater than a set value and less than or equal to an angle corresponding to half a tooth pitch; whether the actual clamping force of the caliper when the motor is at rest is greater than or equal to the calibration clamping force; whether the direction of the solenoid feedback current is a locking direction.

6. The parking control method according to claim 4, characterized by, The continuously adjusting of the actual falling point of the pawl on the ratchet wheel comprises: The current actual drop point is moved by one tooth pitch in the clamping rotation direction of the ratchet wheel to determine an adjusted actual drop point.

7. The parking control method according to claim 6, characterized by, In the case where n is equal to 2, the determining of the actual drop point of the pawl on the ratchet wheel based on the preset condition comprises: The first actual drop point of the pawl on the ratchet wheel is determined based on the preset condition. The motor rotation angle of the actual drop point is determined as a target motor rotation angle according to the system conversion model. The motor rotation angle of the first actual drop point is determined as a first target motor rotation angle according to the system conversion model. After the motor is controlled to rotate to the first target motor rotation angle and the pawl is controlled to drop, the method further comprises: First locking state feedback information is acquired, and whether the first locking satisfies the parking condition is determined according to the first locking state feedback information. If not, the first actual drop point is moved by one tooth pitch in the clamping rotation direction of the ratchet wheel to determine a second actual drop point. The motor rotation angle of the second actual drop point is determined as a second target motor rotation angle according to the system conversion model. The motor is controlled to rotate to the second target motor rotation angle, and the pawl is controlled to drop for the second locking.

8. The parking control method according to claim 7, characterized by, After the motor is controlled to rotate to the second target motor rotation angle and the pawl is controlled to drop for the second locking, the method further comprises: Second locking state feedback information is acquired, and whether the second locking satisfies the parking condition is determined according to the second locking state feedback information. If the second locking satisfies the parking condition, the parking mechanism is controlled to keep the current state, the parking is completed, and ratchet wheel tooth loss fault information is generated and reported. If the second locking does not satisfy the parking condition, the parking is released, and pawl and / or solenoid fault information is generated and reported.

9. The parking control method according to claim 1, characterized by, Before the calibrated motor rotation angle is determined according to the system stiffness curve and the calibrated clamping force, the method further comprises: An initial stiffness curve of the system is acquired through off-line calibration. A correction amount of the initial stiffness curve is generated according to historical operation data of the parking mechanism in each ignition cycle of the vehicle through a correction model. The initial stiffness curve is updated according to the correction amount to obtain a system stiffness curve for the current ignition cycle.

10. A parking control device characterized by comprising: The method comprises: An information acquisition module is configured to acquire parking working condition information of the vehicle, and determine a calibrated clamping force of the caliper on the brake disc according to the parking working condition information. A calibrated rotation angle determination module is configured to determine a calibrated motor rotation angle according to a system stiffness curve and the calibrated clamping force, wherein the system stiffness curve represents a corresponding relationship between the clamping force and the motor rotation angle. A drop point determination module is configured to determine a drop point of the pawl on the ratchet wheel according to a system conversion model and the calibrated motor rotation angle, and determine an actual drop point of the pawl on the ratchet wheel based on a preset condition, wherein the system conversion model is used to represent a corresponding relationship between the drop position of the pawl on the ratchet wheel and the motor rotation angle. A target rotation angle determining module is configured to determine a motor rotation angle of the actual falling point according to the system conversion model, and determine the motor rotation angle of the actual falling point as a target motor rotation angle. A control module is configured to control the motor to rotate to the target motor rotation angle, and control the pawl to fall.

11. A vehicle characterized by comprising: The parking control method according to any one of claims 1-9 is used for parking.

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