Four-wheel redundant parking control method and system based on EMB brake-by-wire

Abstract

The invention provides a four-wheel redundant parking control method and system based on EMB brake-by-wire, and belongs to the technical field of vehicle braking. Comprising the steps that based on a dynamic parking force model, target clamping force of each wheel of a vehicle is calculated according to vehicle state parameters, so that a four-wheel independent parking force instruction is generated; performing asymmetric power distribution dominated by a front shaft on a four-wheel independent parking force instruction, monitoring the states of a power supply, a control unit and an actuator of each EMB actuator in a dynamic adjustment process in real time, and activating a corresponding redundancy mechanism when detecting that a single point fails; and independent parking force control is carried out on each EMB actuator through a closed-loop controller. According to the invention, four-wheel braking force cooperative control during vehicle parking can be realized on the basis of covering full-link redundancy of a power supply, communication and an actuator.

Description

Technical Field

[0001] The present invention belongs to the technical field of vehicle braking, and in particular relates to a four-wheel redundant parking control method and system based on EMB brake-by-wire. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] With the rapid development of intelligent and electrified vehicles, the safety, dynamic adaptability, and redundancy reliability of vehicle parking systems have become key technical bottlenecks restricting the development of smart electric vehicles. Currently, mainstream parking technologies are mainly divided into two categories: traditional electronic parking brakes (EPB) and electronic mechanical brakes (EMB). However, both have significant technical defects and are difficult to meet the needs of high-slope, complex load, and high-safety scenarios. For example: (1) Lack of coordinated four-wheel control and insufficient longitudinal stability. Existing EMB systems generally adopt the "rear wheel braking - front wheel transmission lock" mode when parking, and fail to achieve closed-loop control of the four-wheel independent clamping force. When the vehicle is on a high slope and the front wheel transmission lock mechanism fails, the rear wheel brake alone cannot balance the longitudinal torque, which can easily cause the vehicle to slide down the slope, posing a risk of longitudinal instability.

[0004] (2) The redundancy safety level is insufficient and cannot meet high safety standards. Although mainstream EMB systems use a dual-MCU redundant architecture, they do not implement a full-link redundancy design. For example, the power supply layer relies only on a single main power supply, communication relies on a single CAN bus, and the actuator does not have a backup drive unit. Therefore, when a single point of failure occurs (such as a main power failure), the braking force will drop sharply, posing a safety risk in autonomous driving scenarios.

[0005] (3) Large deviations between dynamic parameter perception and calculation. The existing EMB system's parking force calculation model has significant parameter perception blind spots, resulting in deviations in parking force calculation. Furthermore, it is unable to estimate the vehicle mass in real time, causing the parking force allocation based on fixed mass parameters to be out of line with actual demand. This is especially true in the no-load / full-load switching scenario, where excessive or insufficient parking force is likely to occur. Summary of the Invention

[0006] In order to overcome the shortcomings of the above-mentioned prior art, the present invention provides a four-wheel redundant parking control method and system based on EMB wire control braking, which can realize the coordinated control of the four-wheel braking force when the vehicle is parked on the basis of full-link redundancy covering power supply, communication, and actuator.

[0007] To achieve the above objectives, one or more embodiments of the present invention provide the following technical solutions: A first aspect of the present invention provides a four-wheel redundant parking control method based on EMB brake-by-wire.

[0008] A four-wheel redundant parking control method based on EMB brake-by-wire control, comprising: Real-time collection of vehicle status parameters through multi-source sensors; Based on the dynamic parking force model, the target clamping force of each wheel of the vehicle is calculated according to the obtained vehicle state parameters to generate four-wheel independent parking force commands; The four-wheel independent parking force command is subjected to a front-axle-dominated asymmetric power distribution, i.e., the front axle is higher than the rear axle as a basic distribution ratio, and is dynamically adjusted in real time according to the vehicle body posture; The power supply, control unit, and actuator status of each EMB actuator during dynamic adjustment are monitored in real time. When a single-point failure is detected, the corresponding redundancy mechanism is activated; and each EMB actuator is independently controlled for parking force through a closed-loop controller.

[0009] Furthermore, the multi-source sensor includes: a dual-axis MEMS tilt sensor installed on the vehicle chassis, a pressure sensor integrated into the vehicle suspension, and an infrared thermal imager installed on the vehicle wheel end.

[0010] Furthermore, the basic distribution ratio of the front axle is higher than that of the rear axle at 6:4. When the vehicle is parked and the parking slope is greater than the slope threshold or the vehicle load is greater than the load threshold, the proportion of the front axle braking force is automatically increased.

[0011] Furthermore, it also includes thermal decay compensation, that is, when the brake disc temperature is higher than the brake temperature limit, the forced cooling mode is activated and the friction coefficient is corrected; the parameters in the dynamic parking force model are corrected with the corrected friction parameters.

[0012] Furthermore, the redundancy mechanism adopts a dual-level redundant security architecture, including: Power supply redundancy: Provides two completely independent power supplies for EMB actuators; Control redundancy: The domain controller uses a dual-chip architecture with a primary and a secondary. If the primary chip fails, the secondary chip takes over control within millimeters. Actuator redundancy: When a single-wheel EMB actuator fails, the adjacent wheel braking force compensation algorithm is activated to maintain the total parking force.

[0013] Furthermore, the specific implementation of the actuator redundancy includes: when the left front wheel of the vehicle fails, the braking force of the right front wheel and the left rear wheel of the vehicle is increased proportionally; when the right rear wheel of the vehicle fails, the braking force of the left rear wheel and the right front wheel of the vehicle is increased proportionally.

[0014] Furthermore, the dynamic parking force model is: ; in, Indicates the Target clamping force for each wheel, represents the distribution coefficient, Indicates the vehicle mass, represents the acceleration due to gravity, represents the slope angle, represents the horizontal position of the center of mass, Indicates wheelbase, Represents the safety margin factor.

[0015] A second aspect of the present invention provides a four-wheel redundant parking control system based on EMB brake-by-wire.

[0016] A four-wheel redundant parking control system based on EMB brake-by-wire, comprising: The four-wheel independent EMB actuator units are configured as follows: each EMB actuator unit contains a brushless DC motor, a planetary gear reduction mechanism, a ball screw transmission assembly and a clamping force sensor, supporting single-wheel independent force control; The multi-source sensing network is configured to: integrate an inclination sensor, a suspension pressure sensor, and an infrared temperature sensor; The dual-chip domain controller is configured to: fuse multi-source perception data through Kalman filtering and execute a dynamic parking force distribution algorithm. Furthermore, the dual-chip domain controller realizes zero-copy transmission of sensor data in a multi-source perception network through a DMA channel; and executes CRC32 communication check multiple times in a cycle, automatically switching communication channels when the error rate exceeds the standard.

[0017] Furthermore, the EMB execution unit is installed on the inner side of the vehicle's wheel hub and is mechanically integrated with the brake caliper of the wheel hub; the clamping force sensor is embedded in the end of the ball screw to provide real-time feedback of the actual braking force to the dual-chip domain controller.

[0018] One or more of the above technical solutions have the following beneficial effects: (1) The present invention achieves independent force control of each wheel through four-wheel independent EMB execution units, generates four-wheel independent parking force commands in combination with a dynamic parking force model, and adopts a front-axle-dominated asymmetric power distribution strategy (basic ratio 6:4, dynamically adjustable to 7:3 based on slope and load), thus achieving closed-loop control of the four-wheel independent clamping force. Without relying on the front wheel transmission locking mechanism, the longitudinal torque can be dynamically balanced based on vehicle state parameters. Therefore, compared with the existing technology, the present invention can avoid the risk of vehicle sliding down the slope due to front wheel locking failure even in high-slope scenarios, significantly improving the vehicle's longitudinal stability when parking.

[0019] (2) The present invention adopts a dual-level redundant safety architecture to achieve full-link redundancy design, including power supply redundancy (two completely independent power supplies), control redundancy (master and slave heterogeneous dual chips, with the slave chip taking over at the millimeter level when the master chip fails), and actuator redundancy (activating the adjacent wheel compensation algorithm when a single wheel fails, such as increasing the braking force of the right front wheel and left rear wheel when the left front wheel fails). At the same time, communication redundancy is ensured through CRC32 communication check and channel switching. This design can still maintain stable parking force in the event of a single point of failure, meeting the high safety standard of ISO 26262 ASIL-D, and effectively avoiding the safety risks caused by a sudden drop in braking force in autonomous driving scenarios.

[0020] (3) This invention uses a multi-source sensing network to collect parameters such as slope angle and suspension support reaction force in real time, estimates vehicle mass based on suspension pressure data, and fuses this data through a Kalman filter. The dynamic parking force model incorporates real-time parameters such as slope angle, center of mass horizontal position, and vehicle mass, and corrects the model parameters using thermal decay compensation (corrected friction coefficient). This overcomes the parameter perception blind spots of existing models, significantly reducing parking force calculation errors and enabling real-time adaptation to empty / full load switching scenarios, avoiding the problem of excessive or insufficient parking force.

[0021] Advantages of additional aspects of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0023] Figure 1 This is a flow chart of a four-wheel redundant parking control method based on EMB brake-by-wire in Example 1 of the present invention. DETAILED DESCRIPTION

[0024] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention belongs.

[0025] It should be noted that the terms used herein are for describing particular embodiments only and are not intended to limit the exemplary embodiments according to the present invention.

[0026] In the absence of conflict, the embodiments of the present invention and the features thereof may be combined with each other.

[0027] Example 1 This embodiment discloses a four-wheel redundant parking control method based on EMB brake-by-wire.

[0028] like Figure 1 As shown, a four-wheel redundant parking control method based on EMB brake-by-wire includes: Step S1: collecting vehicle status parameters in real time through multi-source sensors; Step S2: Calculating the target clamping force of each wheel of the vehicle based on the obtained vehicle state parameters based on the dynamic parking force model to generate a four-wheel independent parking force command; Step S3, performing a front-axle-dominated asymmetric power distribution on the four-wheel independent parking force command, i.e., using a higher distribution ratio on the front axle than on the rear axle as a basic distribution ratio, and dynamically adjusting the distribution ratio in real time according to the vehicle body posture; Step S4: monitor the power supply, control unit, and actuator status of each EMB actuator in real time during the dynamic adjustment process. When a single point failure is detected, activate the corresponding redundancy mechanism; and independently control the parking force of each EMB actuator through a closed-loop controller.

[0029] Based on the above process, the present invention can achieve coordinated control of the four-wheel braking force during parking, based on full-link redundancy covering power supply, communication, and actuators. To facilitate understanding of the technical solution of the present invention, the specific implementation method of the technical solution of the present invention is further explained and illustrated below.

[0030] In step S1, vehicle state parameters are collected in real time through multi-source sensors.

[0031] The multi-source sensor design includes a dual-axis MEMS inclination sensor mounted on the vehicle chassis, a pressure sensor integrated into the vehicle suspension, and an infrared thermal imager installed near the wheel-end brake calipers. This multi-source sensor design enables accurate and real-time acquisition of vehicle status parameters, thereby specifically addressing the technical flaw of existing EMB systems, which suffers from large deviations in dynamic parameter perception and calculation.

[0032] As an optional embodiment, the dual-axis MEMS inclination sensor adopts the dual-axis MEMS inclination sensor of Bosch SMI730 series with an accuracy of , used to collect slope angles in real time, with a sampling frequency of 1kHz. The pressure sensor uses Continental's four-channel suspension pressure sensor with a range of 0-5000kg, which is used to collect the reaction forces of each suspension support. The infrared thermal imager can use an infrared thermal imager such as the FLIR A655sc model, which must meet the following requirements: a temperature measurement range covering -20°C to 1500°C, a temperature measurement accuracy of ≤±2°C, a sampling frequency of ≥100Hz, and the ability to output brake disc surface temperature field distribution data in real time. It also supports data interaction with the dual-chip domain controller via the SPI interface to meet the rapid response requirements when the brake disc temperature exceeds 300°C.

[0033] The collected vehicle status parameters can be transmitted using the DMA channel of the TI TMS570LS1227 MCU to achieve zero-copy sensor data transmission, and the Kalman filter can be used to eliminate road bumps and interference, keeping the error within 2%.

[0034] In step S2 , based on the dynamic parking force model, the target clamping force of each wheel of the vehicle is calculated according to the obtained vehicle state parameters to generate a four-wheel independent parking force command.

[0035] 1) Dynamic calculation of parameters.

[0036] A. Calculate the vehicle mass, namely: ; in, Indicates the vehicle mass, represents the acceleration due to gravity, Indicates the The suspension support reaction force of an independent suspension, Indicates the slope angle.

[0037] B. Real-time update of the center of mass horizontal position (based on the suspension pressure difference between the front and rear axles ),Right now: ; in, represents the horizontal position of the center of mass, Represents the total reaction force of the rear axle suspension, represents the total reaction force of the front axle suspension, Indicates wheelbase.

[0038] C. Set the dynamic threshold of the safety margin according to the ISO 26262 ASIL-D standard, namely: ; in, represents the safety margin, Indicates the The suspension support reaction force of an independent suspension, Indicates the slope angle.

[0039] 2) Dynamic parking force calculation.

[0040] Based on the dynamic parking force model, the target clamping force of each wheel of the vehicle is calculated according to the obtained vehicle state parameters. The dynamic parking force model is: ; in, Indicates the Target clamping force for each wheel, represents the distribution coefficient, Indicates the vehicle mass, represents the slope angle, represents the horizontal position of the center of mass, Indicates wheelbase, Represents the safety margin factor.

[0041] Furthermore, the distribution coefficient According to the tire-ground friction coefficient Perform dynamic adjustments, namely: ; The calculated target clamping force for each of the four wheels forms the core basis for the parking force command. Specifically, the dual-chip domain controller calculates the target clamping force for each wheel based on the dynamic parking force model and converts these target values ​​into parking force commands in the form of electrical signals. This parking force command includes parameters such as the clamping force values ​​to be achieved by each wheel and the execution timing, and is distributed according to the basic ratio of asymmetric power distribution in step S3 (or the dynamically adjusted ratio), ensuring that the four-wheel parking force is output in a coordinated manner according to the preset strategy.

[0042] In step S3, the four-wheel independent parking force command (the target clamping force command value of each wheel) is subjected to asymmetric power distribution dominated by the front axle, that is, the front axle is higher than the rear axle as the basic distribution ratio, and is dynamically adjusted in real time according to the vehicle body posture.

[0043] The basic braking force distribution ratio is 6:4, with the front axle being higher than the rear axle. This means an asymmetric distribution command of 60% front axle and 40% rear axle is output. The ratio is dynamically adjusted based on vehicle posture. For example, when the vehicle is parked on a slope greater than a slope threshold or the vehicle load exceeds a load threshold, the front axle braking force ratio is automatically increased to 7:3. The specific values ​​of the slope threshold and load threshold can be set based on actual conditions and are not specifically limited in this embodiment.

[0044] Through this asymmetric power distribution method, on the one hand, it breaks through the inherent mode of "rear wheel dominant, front wheel dependent on gearbox lock" commonly relied on in existing technologies, and improves the longitudinal stability of the vehicle during braking; on the other hand, it can dynamically adapt to high-slope scenarios to avoid insufficient or excessive parking force.

[0045] In step S4, the power supply, control unit, and actuator status of each EMB actuator during the dynamic adjustment process are monitored in real time. When a single point failure is detected, the corresponding redundancy mechanism is activated; and the parking force of each EMB actuator is independently controlled through a closed-loop controller.

[0046] The redundancy mechanism adopts a two-level redundant safety architecture, including: A. Power supply redundancy: The vehicle provides two completely independent redundant power supplies for the EMB actuator. When a single power supply fails, it can still support 9 times 2.44 More than brake.

[0047] B. Control redundancy: The domain controller uses a master and slave heterogeneous dual chip. When the master chip fails, the slave chip takes over control within millimeter level.

[0048] C. Actuator redundancy: When a single-wheel EMB actuator fails, the adjacent wheel braking force compensation algorithm is activated to maintain more than 75% of the parking force.

[0049] By adopting the above-mentioned dual-level redundant safety architecture, the core defect of the existing technology, that is, insufficient redundant safety level and inability to meet high safety standards, can be avoided; at the same time, by achieving full-link redundancy of power supply, control, and actuator, the risk of a sudden drop in braking force in the event of a single point failure can also be avoided.

[0050] Furthermore, actuator redundancy is specifically implemented by proportionally increasing the braking force on the right front and left rear wheels when the left front wheel fails; and proportionally increasing the braking force on the left rear and right front wheels when the right rear wheel fails. This targeted adjacent wheel compensation strategy accurately compensates for the loss of braking force after a single wheel failure while maintaining longitudinal torque balance, further addressing the existing drawbacks of a sudden drop in total parking force and torque imbalance when a single wheel actuator fails.

[0051] In actual implementation, the target clamping force calculated in step S2 and the parking force command generated in step S3 provide the "target value" for fuzzy PID control. Specifically, the fuzzy PID input deviation is calculated based on the difference between the command target value and the actual feedback value. The output of the fuzzy PID control directly drives the EMB actuator, while the actual clamping force data it feeds back provides a basis for redundancy mechanisms (such as actuator failure detection), ensuring the closed-loop stability of parking force control. Specifically, fuzzy PID control is achieved by integrating fuzzy control with PID control algorithms. The deviation between the target clamping force and the actual clamping force fed back by the EMB actuator, as well as the rate of change of the deviation, is used as input. Based on a preset fuzzy rule base (e.g., "when the deviation is large and changes rapidly, increase the proportional coefficient and decrease the integral coefficient"), fuzzy inference is used to output corrections to the PID parameters. The PID controller parameters are updated in real time to generate a PWM drive signal, controlling the speed of the EMB actuator's brushless DC motor and the amount of ball screw thrust, ultimately ensuring that the actual clamping force converges quickly to the target value.

[0052] To ensure effective braking, thermal fade compensation is also included during the parking process. This means that when the brake disc temperature exceeds the brake temperature limit, forced cooling is activated and the friction coefficient is corrected. The corrected friction coefficient is then used to adjust the parameters in the dynamic parking force model. This thermal fade compensation mechanism avoids the significant deviations in dynamic parameter perception and calculation that occur in existing EMB systems due to a failure to consider the impact of brake disc temperature on the friction coefficient. This ensures accurate parking force calculation and stable braking performance by: 1) correcting friction coefficient deviations to avoid distortion in parking force calculations; 2) activating forced cooling to proactively restore braking performance; and 3) adapting to complex operating conditions and improving reliability in extreme scenarios.

[0053] As an optional embodiment, the brake disc temperature is monitored by an infrared thermal imager. , the forced cooling mode is activated and the friction coefficient is corrected, that is: ; in, represents the corrected friction coefficient, Indicates the brake disc temperature, Indicates the initial friction coefficient between the brake disc and the brake pad at a reference temperature of 100°C.

[0054] Based on the above process, the present invention can realize the coordinated control of the four-wheel braking force when the vehicle is parked on the basis of full-link redundancy covering power supply, communication, and actuator.

[0055] Example 2 This embodiment discloses a four-wheel redundant parking control system based on EMB brake-by-wire.

[0056] A four-wheel redundant parking control system based on EMB brake-by-wire, comprising: The four-wheel independent EMB actuator units are configured as follows: each EMB actuator unit integrates a brushless DC motor, a planetary gear reduction mechanism, a ball screw transmission assembly and a clamping force sensor, and supports independent adjustment of a single-wheel braking force of 0-2000N.

[0057] The multi-source perception network is configured to integrate an inclination sensor, a suspension pressure sensor, and an infrared temperature sensor; wherein the infrared temperature sensor can be an infrared thermal imager.

[0058] The dual-chip domain controller is configured to: fuse multi-source perception data through Kalman filtering and execute a dynamic parking force distribution algorithm; the main and auxiliary dual chips of the dual-chip domain controller and the four wheel-end EMB calipers are powered by dual channels to achieve power redundancy.

[0059] Furthermore, the dual-chip domain controller realizes zero-copy transmission of sensor data in the multi-source perception network through the DMA channel; and executes CRC32 communication check repeatedly in a loop, and automatically switches the communication channel when the error rate exceeds the standard. As an optional embodiment, the CRC32 check can be executed every 50ms, and the error rate can be The communication channel is automatically switched and the functional safety mechanism is triggered synchronously.

[0060] Furthermore, the EMB actuator unit is installed on the inner side of the vehicle's wheel hub and is mechanically integrated with the wheel hub's brake caliper; the clamping force sensor is embedded in the end of the ball screw to provide real-time feedback of the actual braking force to the dual-chip domain controller.

[0061] Based on this systematic design, each component (multi-source perception network, dual-chip domain controller, and EMB actuator) collaborates to achieve parking through a closed-loop "perception-decision-execution-feedback" chain. The specific logic is as follows: the master chip in the dual-chip domain controller integrates data collected by the multi-source perception network through a Kalman filter. It calculates the target clamping force based on a dynamic parking force model and generates a parking force command using an asymmetric allocation strategy. The slave chip in the dual-chip domain controller monitors the master chip's status and sensor data integrity in real time, seamlessly taking over the decision-making logic if the master chip fails. Furthermore, a CRC32 checksum ensures communication link reliability, switching to a backup communication channel if the error rate exceeds the specified limit. Upon receiving the parking force command from the domain controller, the EMB actuator uses fuzzy PID control to drive the brushless DC motor and planetary gear mechanism, which in turn drives the ball screw to clamp the brake pads and discs. If a single-point failure in the power supply, communication, or actuator is detected, the domain controller activates redundancy mechanisms (such as switching to the backup power source if a single power source fails, or initiating the adjacent wheel compensation algorithm if a single wheel actuator fails) to ensure that parking force remains above 75%. Through the collaborative process of real-time perception by sensors - dynamic decision-making by domain controllers - precise action by actuators - closed-loop correction of feedback data, dynamic distribution of four-wheel parking force, redundant safety assurance and high-stability parking are ultimately achieved.

[0062] Those skilled in the art will appreciate that the modules or steps of the present invention described above can be implemented using a general-purpose computer device. Alternatively, they can be implemented using program code executable by a computing device, which can then be stored in a storage device and executed by the computing device. Alternatively, they can be fabricated into separate integrated circuit modules, or multiple modules or steps can be fabricated into a single integrated circuit module for implementation. The present invention is not limited to any specific combination of hardware and software.

[0063] The above describes the specific embodiments of the present application in combination with the drawings, but is not a limitation on the protection scope of the present application. Those skilled in the art should understand that various modifications or variations made by those skilled in the art on the basis of the technical solutions of the present application without creative labor are still within the protection scope of the present application.

Claims

1. A four-wheel redundant parking control method based on EMB brake-by-wire, characterized in that: include: Real-time collection of vehicle status parameters through multi-source sensors; Based on the dynamic parking force model, the target clamping force of each wheel of the vehicle is calculated according to the obtained vehicle state parameters to generate four-wheel independent parking force commands; The four-wheel independent parking force command is subjected to a front-axle-dominated asymmetric power distribution, i.e., the front axle is higher than the rear axle as a basic distribution ratio, and is dynamically adjusted in real time according to the vehicle body posture; The power supply, control unit, and actuator status of each EMB actuator during dynamic adjustment are monitored in real time. When a single-point failure is detected, the corresponding redundancy mechanism is activated; and each EMB actuator is independently controlled for parking force through a closed-loop controller.

2. The four-wheel redundant parking control method based on EMB brake-by-wire according to claim 1, characterized in that: The multi-source sensor includes: a dual-axis MEMS tilt sensor installed on the vehicle chassis, a pressure sensor integrated into the vehicle suspension, and an infrared thermal imager installed on the vehicle wheel end.

3. The four-wheel redundant parking control method based on EMB brake-by-wire as claimed in claim 1, characterized in that: The basic distribution ratio of the front axle is higher than that of the rear axle at 6:

4. When the vehicle is parked and the slope is greater than the slope threshold or the vehicle load is greater than the load threshold, the proportion of front axle braking force is automatically increased.

4. The four-wheel redundant parking control method based on EMB brake-by-wire as claimed in claim 1, characterized in that: It also includes thermal fade compensation, that is, when the brake disc temperature is higher than the brake temperature limit, the forced cooling mode is activated and the friction coefficient is corrected; the parameters in the dynamic parking force model are corrected with the corrected friction parameters.

5. The four-wheel redundant parking control method based on EMB brake-by-wire as claimed in claim 1, characterized in that: The redundancy mechanism adopts a two-level redundant safety architecture, including: Power supply redundancy: Provides two completely independent power supplies for EMB actuators; Control redundancy: The domain controller uses a dual-chip architecture with a primary and a secondary. If the primary chip fails, the secondary chip takes over control within millimeters. Actuator redundancy: When a single-wheel EMB actuator fails, the adjacent wheel braking force compensation algorithm is activated to maintain the total parking force.

6. The four-wheel redundant parking control method based on EMB brake-by-wire as claimed in claim 5, characterized in that: The specific implementation of the actuator redundancy includes: when the left front wheel of the vehicle fails, the braking force of the right front wheel and the left rear wheel of the vehicle is proportionally increased; when the right rear wheel of the vehicle fails, the braking force of the left rear wheel and the right front wheel of the vehicle is proportionally increased.

7. The four-wheel redundant parking control method based on EMB brake-by-wire as claimed in claim 1, characterized in that: The dynamic parking force model is: ； in, Indicates the Target clamping force for each wheel, represents the distribution coefficient, Indicates the vehicle mass, represents the acceleration due to gravity, represents the slope angle, represents the horizontal position of the center of mass, Indicates wheelbase, Represents the safety margin factor.

8. A four-wheel redundant parking control system based on EMB brake-by-wire, characterized in that: include: The four-wheel independent EMB actuator units are configured as follows: each EMB actuator unit contains a brushless DC motor, a planetary gear reduction mechanism, a ball screw transmission assembly and a clamping force sensor, supporting single-wheel independent force control; The multi-source sensing network is configured to: integrate an inclination sensor, a suspension pressure sensor, and an infrared temperature sensor; The dual-chip domain controller is configured to: fuse multi-source perception data through Kalman filtering and execute a dynamic parking force distribution algorithm.

9. The four-wheel redundant parking control system based on EMB brake-by-wire as claimed in claim 8, characterized in that: The dual-chip domain controller realizes zero-copy transmission of sensor data in a multi-source perception network through a DMA channel; and executes CRC32 communication check repeatedly in a cycle, automatically switching communication channels when the error rate exceeds the standard.

10. The four-wheel redundant parking control system based on EMB brake-by-wire according to claim 8, characterized in that: The EMB actuator is installed on the inside of the vehicle's wheel hub and is mechanically integrated with the wheel hub's brake caliper; the clamping force sensor is embedded in the end of the ball screw to provide real-time feedback of the actual braking force to the dual-chip domain controller.

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