Longitudinal control method of vehicle, vehicle and storage medium

Abstract

The invention relates to a longitudinal control method for a vehicle, the vehicle and a storage medium, and the method comprises the steps: obtaining a preset target acceleration, and calculating the actual acceleration of the vehicle; calculating a distributed acceleration based on the target acceleration and the actual acceleration of the vehicle; the maximum negative torque parameter of a whole vehicle driving mechanism of the vehicle is obtained; calculating a torque request value of a whole vehicle driving mechanism of the vehicle and a brake pressure request value of a main cylinder brake mechanism of the vehicle based on a comparison result of the maximum negative torque parameter and the distributed acceleration; and based on the torque request value and the braking pressure request value, a whole vehicle driving mechanism and a main cylinder braking mechanism are combined to conduct braking operation on the vehicle. By means of the vehicle longitudinal control method, the problem that an ACC software architecture cannot adapt to and adopt EBS and other novel braking system architectures is solved, and the vehicle longitudinal control method capable of coordinately controlling the torque output of the vehicle control unit and the braking force output of the novel braking system is achieved.

Description

Technical Field

[0001] The present application relates to the field of vehicle dynamics control, and in particular to a longitudinal control method of a vehicle, a vehicle and a storage medium. Background Art

[0002] Adaptive Cruise Control (ACC), the core function of Advanced Driving Assistance System (ADAS), is an important part of modern intelligent driving. It can automatically adjust the speed of the vehicle based on the speed changes of the vehicle in front and maintain a preset distance from the vehicle in front, thereby greatly improving driving safety and comfort.

[0003] At present, the realization of adaptive cruise control (ACC) function mainly depends on the upper and lower controllers. The upper controller is responsible for calculating the current required acceleration of the vehicle based on the current perception system, combined with information such as vehicle distance and speed; while the lower controller (i.e., VLC module, Vehicle Longitudinal Control, brake for vehicle longitudinal control) calculates the required torque and / or hydraulic value of the vehicle according to the required acceleration, and sends it to the torque execution unit and / or hydraulic unit to realize the longitudinal drive and braking of the whole vehicle. With the popularization of electrification and intelligence of automobiles, more and more OEMs are adopting a new brake system structure, that is, replacing the traditional vacuum booster with EBS (Electronic Brake Booster). EBS uses wire control brake technology, which can respond to the brake pressure request of the driver or ADAS more quickly, with faster braking response and shorter braking distance. However, under this new braking system architecture, the main actuator of the braking system has changed from ESC (Electronic Stability Control) to EBS, which has led to a significant change in the interaction logic between ADAS and the braking system actuator (when EBS fails, ESC can also intervene in braking, and in most cases, braking is performed by EBS). The traditional ACC software architecture is no longer able to adapt to this new interaction method, so a new VLC torque control logic needs to be developed to adapt to the latest braking system architecture.

[0004] Currently, no effective solution has been proposed for the problem that the ACC software architecture in related technologies cannot adapt to new braking system architectures such as EBS. Summary of the invention

[0005] The embodiments of the present application provide a longitudinal control method of a vehicle, a vehicle and a storage medium, so as to at least solve the problem in the related art that the ACC software architecture cannot adapt to the new braking system architecture such as EBS.

[0006] In a first aspect, an embodiment of the present application provides a longitudinal control method for a vehicle, comprising:

[0007] Obtain the preset target acceleration and calculate the actual acceleration of the vehicle;

[0008] Calculating a distributed acceleration based on the target acceleration and the actual acceleration of the vehicle;

[0009] Obtaining a maximum negative torque parameter of a vehicle drive mechanism of the vehicle;

[0010] Calculating a torque request value of a vehicle drive mechanism of the vehicle and a brake pressure request value of a master cylinder brake mechanism of the vehicle based on a comparison result of the maximum negative torque parameter and the distributed acceleration;

[0011] Based on the torque request value and the brake pressure request value, the vehicle driving mechanism and the master cylinder brake mechanism are combined to perform a braking operation on the vehicle.

[0012] In some embodiments, the calculating the distributed acceleration based on the target acceleration and the actual acceleration of the vehicle includes:

[0013] Get vehicle load value;

[0014] Based on the target acceleration, the vehicle load value, and the vehicle actual acceleration, a distributed acceleration is calculated.

[0015] In some embodiments, obtaining the vehicle load value includes:

[0016] Acquiring real-time vehicle information of the vehicle;

[0017] Based on the real-time vehicle information, a vehicle running resistance and a vehicle slope resistance are calculated, and based on the vehicle running resistance and the vehicle slope resistance, the vehicle load value is acquired.

[0018] In some embodiments, the calculating the distributed acceleration based on the target acceleration, the vehicle load value and the actual vehicle acceleration includes:

[0019] calculating a feedforward acceleration based on the target acceleration and the vehicle load value;

[0020] calculating a feedback acceleration based on a difference between the target acceleration and the actual acceleration of the vehicle;

[0021] The distributed acceleration is calculated based on the feedforward acceleration and the feedback acceleration.

[0022] In some embodiments, obtaining the maximum negative torque parameter of the vehicle drive mechanism includes:

[0023] Acquire a preset first torque relationship, where the first torque relationship is used to indicate a mapping relationship between a vehicle speed and an ideal torque value;

[0024] determining an ideal torque parameter corresponding to an actual vehicle speed of the vehicle based on the first torque relationship;

[0025] Acquire a second torque relationship calibrated for the actual vehicle, where the second torque relationship is used to indicate a mapping relationship between a vehicle speed and a calibrated torque value;

[0026] determining a calibrated torque parameter corresponding to the actual vehicle speed based on the second torque relationship;

[0027] The maximum negative torque parameter is determined based on the ideal torque parameter and the calibrated torque parameter.

[0028] In some embodiments, the calculating of the torque request value of the vehicle drive mechanism and the brake pressure request value of the master cylinder brake mechanism of the vehicle based on the comparison result of the maximum negative torque parameter and the distributed acceleration includes:

[0029] If the distributed acceleration exceeds the acceleration corresponding to the maximum negative torque parameter, the distributed acceleration is distributed to the vehicle drive mechanism to calculate the torque request value;

[0030] On the contrary, the distributed acceleration is distributed to the whole vehicle driving mechanism and the master cylinder brake mechanism, and the brake pressure request value and the torque request value are calculated based on the distributed acceleration.

[0031] In some embodiments, the step of performing a braking operation on the vehicle based on the torque request value and the brake pressure request value in combination with the vehicle drive mechanism and the master cylinder brake mechanism includes:

[0032] Acquiring real-time vehicle information of the vehicle;

[0033] Calculating a vehicle driving slope value based on the real-time vehicle information;

[0034] Calculating a follow-stop pressure request value based on the vehicle driving slope value; wherein the follow-stop pressure request value is used to determine the braking state of the vehicle;

[0035] A braking operation is performed on the vehicle according to the vehicle braking state, the brake pressure request value, and the torque request value.

[0036] In some embodiments, performing a braking operation on the vehicle according to the vehicle braking state, the brake pressure request value and the torque request value includes:

[0037] The vehicle braking state includes a driving state and a following parking state;

[0038] If the vehicle braking state is the driving state, performing a braking operation on the vehicle based on a torque request value and a brake pressure request value;

[0039] If the vehicle braking state is the follow-stop state, the brake pressure request value is updated based on the follow-stop pressure request value to obtain an updated pressure request value, and a braking operation is performed on the vehicle according to the updated pressure request value.

[0040] In a second aspect, an embodiment of the present application provides a vehicle, the vehicle comprising a vehicle drive mechanism, a master cylinder brake mechanism and a controller;

[0041] The controller includes a memory and a processor, wherein a computer program is stored in the memory, and the processor is configured to run the computer program to execute the longitudinal control method of the vehicle described in the first aspect.

[0042] In a third aspect, an embodiment of the present application provides a storage medium having a computer program stored thereon, which, when executed by a processor, implements the longitudinal control method of a vehicle as described in the first aspect above.

[0043] Compared with the related art, the longitudinal control method of the vehicle provided in the embodiment of the present application solves the problem that the ACC software architecture cannot adapt to new braking system architectures such as EBS by using VCU and EBS for braking under different driving conditions, and realizes a vehicle longitudinal control method that can coordinate the control of the torque output of the vehicle controller and the braking force output of the new braking system.

[0044] Details of one or more embodiments of the present application are set forth in the following drawings and description to make other features, objects, and advantages of the present application more readily apparent. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0046] Figure 1 is a hardware structure block diagram of a terminal of a longitudinal control method for a vehicle according to an embodiment of the present invention;

[0047] Figure 2is a flow chart of a longitudinal control method of a vehicle according to an embodiment of the present application;

[0048] Figure 3 It is a system architecture diagram of the ACC function of the longitudinal control method of the vehicle according to the preferred embodiment of the present application;

[0049] Figure 4 is a VLC module system architecture diagram of a longitudinal control method for a vehicle according to an embodiment of the present application;

[0050] Figure 5 is a functional relationship diagram of ACC negative torque design of the longitudinal control method of the vehicle according to an embodiment of the present application;

[0051] Figure 6 is a jump diagram of a state machine of a longitudinal control method for a vehicle according to an embodiment of the present application;

[0052] Figure 7 is a flow chart of another longitudinal control method of a vehicle according to an embodiment of the present application. DETAILED DESCRIPTION

[0053] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is described and illustrated below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. Based on the embodiments provided in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application. In addition, it can also be understood that although the efforts made in this development process may be complex and lengthy, for ordinary technicians in the field related to the contents disclosed in the present application, some changes such as design, manufacturing or production based on the technical contents disclosed in the present application are only conventional technical means, and should not be understood as insufficient contents disclosed in the present application.

[0054] Reference to "embodiments" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those of ordinary skill in the art that the embodiments described in this application may be combined with other embodiments without conflict.

[0055] Unless otherwise defined, the technical terms or scientific terms involved in this application should be understood by people with ordinary skills in the technical field to which this application belongs. The words "one", "a", "a", "the" and the like involved in this application do not indicate a quantitative limitation, and may represent the singular or plural. The terms "include", "comprise", "have" and any of their variations involved in this application are intended to cover non-exclusive inclusions; for example, a process, method, system, product or device that includes a series of steps or modules (units) is not limited to the listed steps or units, but may also include steps or units that are not listed, or may also include other steps or units inherent to these processes, methods, products or devices. The words "connect", "connected", "coupled" and the like involved in this application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The "multiple" involved in this application refers to greater than or equal to two. "And / or" describes the association relationship of associated objects, indicating that there can be three relationships, for example, "A and / or B" can represent: A exists alone, A and B exist at the same time, and B exists alone. The terms "first", "second", "third" and the like involved in the present application are merely used to distinguish similar objects and do not represent a specific ordering of the objects.

[0056] The method embodiment provided in this embodiment can be executed in a terminal, a computer or a similar computing device. Taking running on a terminal as an example, Figure 1 FIG. 1 is a hardware structure block diagram of a terminal of a longitudinal control method for a vehicle according to an embodiment of the present invention. Figure 1 As shown, the terminal may include one or more ( Figure 1 Only one is shown in the figure) a processor 102 (the processor 102 may include but is not limited to a processing device such as a microprocessor MCU or a programmable logic device FPGA) and a memory 104 for storing data. Optionally, the terminal may also include a transmission device 106 and an input / output device 108 for communication functions. It can be understood by those skilled in the art that Figure 1 The structure shown is for illustration only and does not limit the structure of the above terminal. Figure 1 More or fewer components as shown, or with Figure 1 Different configurations shown.

[0057] The memory 104 can be used to store computer programs, for example, software programs and modules of application software, such as the computer program corresponding to the longitudinal control method of the vehicle in the embodiment of the present invention. The processor 102 executes various functional applications and data processing by running the computer program stored in the memory 104, that is, to implement the above method. The memory 104 may include a high-speed random access memory, and may also include a non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some examples, the memory 104 may further include a memory remotely arranged relative to the processor 102, and these remote memories can be connected to the terminal via a network. Examples of the above network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0058] The transmission device 106 is used to receive or send data via a network. The specific example of the above network may include a wireless network provided by a communication provider of the terminal. In one example, the transmission device 106 includes a network adapter (Network Interface Controller, referred to as NIC), which can be connected to other network devices through a base station so as to communicate with the Internet. In one example, the transmission device 106 can be a radio frequency (Radio Frequency, referred to as RF) module, which is used to communicate with the Internet wirelessly.

[0059] This embodiment provides a longitudinal control method for a vehicle. Figure 2 is a flow chart of a longitudinal control method of a vehicle according to an embodiment of the present application, such as Figure 2 As shown, the process includes the following steps:

[0060] Step S201, obtaining a preset target acceleration and calculating the actual acceleration of the vehicle;

[0061] Among them, the adaptive cruise control (ACC) function can automatically adjust the vehicle's speed according to the set vehicle distance and speed to maintain a safe distance from the vehicle in front; the realization of the ACC function mainly depends on the upper and lower controllers. The upper controller is responsible for calculating the current vehicle demand acceleration based on the current perception system and combined with information such as vehicle distance and speed. The vehicle demand acceleration is the above-mentioned target acceleration; in other words, the target acceleration is the target acceleration output by the ACC upper controller.

[0062] The actual acceleration of the vehicle refers to the acceleration generated by the combined effects of power output, resistance and other factors during the actual driving process of the vehicle. The actual acceleration of the vehicle can be obtained by: the acceleration sensor value provided by ESC (Electronic Stability Control, electronic stability system), and the acceleration value obtained by removing the acceleration component caused by the road slope from the collected acceleration sensor value of the vehicle; wherein, the acceleration sensor provided by ESC refers to a true reflection of the vehicle's motion state, including the effects of various influencing factors. It should be understood that the actual acceleration of the vehicle can also be obtained by collecting signals from sensors such as displacement sensors, velocity sensors, other types of acceleration sensors deployed in the vehicle, and further processing and calculating the collected signals, which will not be repeated here.

[0063] This step obtains the preset target acceleration by precisely controlling the vehicle's acceleration to maintain an appropriate following distance for ACC or to maintain the set target speed. Calculating the vehicle's actual acceleration removes the effect of the slope component on the actual acceleration, which can more accurately evaluate the vehicle's power output and driving status, thereby optimizing the control strategy and improving the vehicle's performance and safety.

[0064] Step S202, calculating the distribution acceleration based on the target acceleration and the actual acceleration of the vehicle;

[0065] Among them, based on the target acceleration and the actual acceleration of the vehicle, through a certain algorithm or strategy (such as PID control algorithm, etc.), the torque that needs to be allocated to each power source is calculated to achieve the target acceleration. This process needs to consider the dynamic characteristics of the vehicle, the friction coefficient between the tire and the ground, the load condition of the vehicle and many other factors. Specifically, it can be selected to eliminate the deceleration caused by the estimated load based on the target acceleration output by the original ACC, and then calculate the distribution acceleration based on the difference between the target acceleration output by the ACC and the actual acceleration of the vehicle. The distribution acceleration is the acceleration value allocated to the vehicle drive mechanism and the master cylinder brake mechanism. The vehicle drive mechanism and the master cylinder brake mechanism are key components of the automobile braking system. The two work together to achieve vehicle deceleration and parking. This step accurately determines the distribution acceleration through the target acceleration and the actual acceleration, which can achieve more accurate control of the vehicle acceleration. Accurate acceleration control helps to reduce the bumps and frustrations of the vehicle and improve driving comfort.

[0066] Step S203, obtaining the maximum negative torque parameter of the vehicle drive mechanism;

[0067] Among them, through the vehicle's braking system sensor or other related equipment, the torque data generated during the braking process is collected in real time and used to calculate the braking torque. These data may include braking pressure, friction coefficient of brake disc or brake drum, wheel speed, etc.; using the collected data, combined with the relevant parameters of the vehicle drive mechanism, a specific algorithm is used to calculate the maximum negative torque that the vehicle drive mechanism can generate under the current braking condition; the maximum negative torque parameter is the maximum negative torque that the vehicle drive mechanism can generate under the current braking condition, and the vehicle drive mechanism of the vehicle is VCU (Vehicle Control Unit, vehicle controller). This step can ensure the smoothness of the vehicle braking process under the braking system's small deceleration condition by accurately obtaining the maximum negative torque parameter of the vehicle's vehicle drive mechanism, while energy recovery improves the cruising range; with accurate data on the maximum negative torque, the braking control strategy can be further optimized, such as adjusting the distribution of braking force, optimizing the braking sequence, etc., thereby improving braking efficiency and comfort, and accurate braking torque control helps reduce unnecessary braking energy consumption and wear of the braking system, and extend the service life of the braking system.

[0068] Step S204, calculating a torque request value of a vehicle drive mechanism and a brake pressure request value of a master cylinder brake mechanism of the vehicle based on a comparison result of the maximum negative torque parameter and the distributed acceleration;

[0069] Among them, the maximum negative torque parameter needs to be converted into a corresponding acceleration value according to the conversion relationship between acceleration and torque, and then this acceleration value is compared with the allocated acceleration; the allocated acceleration is allocated to the vehicle drive mechanism and the master cylinder brake mechanism according to the comparison result, the torque request value required by the vehicle drive mechanism is calculated according to the conversion relationship between acceleration and torque, and the brake pressure request value of the master cylinder brake mechanism is calculated according to the conversion relationship between acceleration and brake pressure. The vehicle drive mechanism of the vehicle is VCU (Vehicle Control Unit); the master cylinder brake mechanism of the vehicle is EBS (Electrical Brake Booster). This step can ensure that the vehicle can provide stable and accurate braking performance under various working conditions by accurately calculating the brake pressure request value of the vehicle drive mechanism and the torque request value of the master cylinder brake mechanism, and during the braking process, if the maximum negative torque parameter can meet the braking requirements, then the system can give priority to using the regenerative braking capacity of the vehicle to recover energy, thereby improving the energy efficiency of the vehicle.

[0070] Step S205 , based on the torque request value and the brake pressure request value, the vehicle driving mechanism and the master cylinder brake mechanism are combined to perform a braking operation on the vehicle.

[0071] Among them, the vehicle drive mechanism VCU brakes the vehicle according to the torque request value and the master cylinder brake mechanism EBS brakes the vehicle according to the brake pressure request value to achieve the best braking effect. This step combines the vehicle drive mechanism and the master cylinder brake mechanism to perform braking operations, which can fully utilize the advantages of the two braking systems, improve the braking response speed, and enable the vehicle to slow down and stop faster in an emergency; and during the braking process, by reasonably coordinating the working states of the two brake mechanisms, it can minimize the energy loss during the braking process and improve energy utilization efficiency.

[0072] Through the above steps, by accurately obtaining the target acceleration and actual acceleration, we can more accurately evaluate the current motion state of the vehicle and provide reliable data support for subsequent control strategies; by allocating the required acceleration to the combined braking mechanism VCU and EBS, and calculating the specific values ​​of the torque and braking pressure indicating the operation of the two braking mechanisms, the vehicle's braking operation is realized, thereby improving the response speed and accuracy of the braking system. The present application solves the problem that the traditional ACC software architecture cannot adapt to new brake system architectures such as EBS by directly allocating the required acceleration to the logic of VCU and EBS; for vehicle non-low-speed and small deceleration conditions, the traditional ACC architecture will produce frequent switching of driving mode and braking mode, and the comfort is not ideal. The present application directly allocates the required acceleration to VCU and EBS. Under this condition, ACC sends negative torque to VCU for direct braking, and no longer distinguishes the corresponding conditions of driving mode and braking mode, thereby improving the comfort of this condition in the ACC function; for general ACC deceleration conditions, since ACC directly sends the brake pressure request value to EBS, compared with the prior art in which ESC performs hydraulic braking, the response speed of ACC deceleration is accelerated, and the control accuracy of ACC is improved. For example, under some emergency braking conditions, the architecture of the present application can shorten the braking distance of ACC and broaden the boundary performance of ACC.

[0073] In some embodiments, the distributed acceleration is calculated based on the target acceleration and the actual acceleration of the vehicle, including:

[0074] Get vehicle load value;

[0075] Based on the target acceleration, the vehicle load value and the actual vehicle acceleration, the distributed acceleration is calculated.

[0076] Among them, the vehicle's own sensor system (such as wheel speed sensors, suspension system sensors, etc.) can be used to collect data in real time, and combined with the vehicle's dynamic model, the load can be estimated. For example, by analyzing the force conditions of the wheels, the current load distribution of the vehicle can be inferred, thereby obtaining an accurate vehicle load value. After obtaining the target acceleration, vehicle load value and actual vehicle acceleration, an algorithm or model is needed to calculate the distribution acceleration. Based on the target acceleration output by the original ACC, the deceleration caused by the estimated vehicle load value can be eliminated, and the distribution acceleration can be comprehensively calculated based on the difference between the target acceleration output by the ACC and the actual acceleration of the vehicle.

[0077] In this embodiment, obtaining an accurate vehicle load value is the basis for subsequent torque control. Changes in the load value will directly affect the dynamic performance and stability of the vehicle. Therefore, by real-time monitoring and obtaining the load value, it can be ensured that the torque control strategy adapts to the actual state of the vehicle more accurately, thereby improving driving safety and comfort; calculating and distributing acceleration based on the target acceleration, the vehicle load value and the actual acceleration of the vehicle can significantly improve the dynamic response performance and stability of the vehicle.

[0078] In some embodiments, obtaining a vehicle load value includes:

[0079] Get real-time vehicle information of the vehicle;

[0080] Based on the real-time vehicle information, the vehicle driving resistance and the vehicle slope resistance are calculated, and based on the vehicle driving resistance and the vehicle slope resistance, the vehicle load value is obtained.

[0081] Among them, the real-time vehicle information of the vehicle can be obtained through various sensors and controllers installed on the vehicle. These sensors and controllers can monitor the status of the vehicle in real time, including but not limited to vehicle speed, gear position, frontal area of ​​the vehicle, curb weight of the vehicle, etc. According to the principle of vehicle dynamics, the vehicle driving resistance mainly includes air resistance and rolling resistance. Air resistance is proportional to the square of vehicle speed, while rolling resistance is related to vehicle weight and road conditions. The controller can calculate the current vehicle driving resistance by combining the received information such as vehicle speed and vehicle weight with the preset air resistance and rolling resistance coefficients. In actual engineering, the actual vehicle calibration will be fine-tuned based on the calculated theoretical value to adapt to the project; the slope resistance mainly depends on the vehicle weight and slope angle. The controller can calculate the current vehicle slope resistance by receiving the vehicle weight information and the slope information obtained through sensors or map data; the calculated vehicle driving resistance and slope resistance are added together to obtain the total resistance of the vehicle in the current driving state, and the vehicle load value is estimated. The vehicle load value reflects the load size borne by the vehicle in the current driving state.

[0082] This embodiment can distribute power more reasonably to improve the vehicle's power performance by accurately calculating the vehicle's driving resistance and slope resistance; accurate resistance calculation enables the controller to more smoothly control the vehicle's acceleration and deceleration process, thereby improving driving comfort and stability; by obtaining accurate vehicle load values, the torque output of the power system can be more accurately controlled to meet the vehicle's driving needs.

[0083] In some embodiments, calculating the distributed acceleration based on the target acceleration, the vehicle load value, and the actual acceleration of the vehicle includes:

[0084] Calculating feedforward acceleration based on target acceleration and vehicle load value;

[0085] Calculating feedback acceleration based on the difference between the target acceleration and the actual acceleration of the vehicle;

[0086] Based on the feedforward acceleration and the feedback acceleration, the distributed acceleration is calculated.

[0087] Among them, the target acceleration signal and vehicle load value signal of the vehicle are received, and a feedforward acceleration calculation model is established. The model can predict the required acceleration according to the target acceleration and vehicle load value. The target acceleration and vehicle load value are input into the feedforward acceleration calculation model to obtain the feedforward acceleration. The feedforward part eliminates the deceleration caused by the estimated load based on the target acceleration output by the original ACC. For example, the target acceleration output by the ACC upper controller is +2m / s 2 , the acceleration generated by the load is estimated to be -0.2m / s 2 , then the feedforward acceleration is +2.2m / s 2 . The actual acceleration of the vehicle is acquired in real time, and the difference between the target acceleration and the actual acceleration, i.e., the acceleration error, is calculated. According to the acceleration error, the feedback acceleration is calculated through the feedback control algorithm. The feedback part is based on the difference between the target acceleration output by ACC and the actual acceleration of the vehicle. According to the PID algorithm, the acceleration component of the feedback part is calculated. The feedforward acceleration and the feedback acceleration are directly summed or weighted to obtain the distributed acceleration. If the weighted sum is used, the weighting coefficient can be adjusted according to actual needs to balance the influence of feedforward control and feedback control. The distributed acceleration is used as the control instruction of the vehicle longitudinal controller, and is distributed and output to the corresponding actuator.

[0088] By considering the vehicle load value, the calculation of the feedforward acceleration in this embodiment can more accurately reflect the acceleration performance of the vehicle under different loads, improve the predictability of acceleration control, and help the vehicle maintain a smooth acceleration process under different working conditions; the calculation of the feedback acceleration corrects the acceleration error in real time, improves the accuracy of acceleration control, enhances the robustness of the system, and can maintain stable acceleration performance under complex working conditions; the calculation of the distributed acceleration realizes the organic combination of feedforward control and feedback control, and improves the comprehensive performance of acceleration control.

[0089] In some embodiments, obtaining the maximum negative torque parameter of the vehicle drive mechanism includes:

[0090] Acquire a preset first torque relationship, where the first torque relationship is used to indicate a mapping relationship between a vehicle speed and an ideal torque value;

[0091] Determining an ideal torque parameter corresponding to an actual vehicle speed of the vehicle based on the first torque relationship;

[0092] Acquire a second torque relationship calibrated for an actual vehicle, where the second torque relationship is used to indicate a mapping relationship between a vehicle speed and a calibrated torque value;

[0093] determining a calibrated torque parameter corresponding to the actual vehicle speed based on the second torque relationship;

[0094] Based on the ideal torque parameter and the calibrated torque parameter, the maximum negative torque parameter is determined.

[0095] Among them, the first torque relationship is the functional relationship between the vehicle speed and the minimum wheel-end torque (maximum negative torque) that the VCU can use. The first torque relationship is generally provided by the VCU supplier and represents the maximum negative torque that the VCU can use; the second torque relationship is the functional relationship between the vehicle speed and the minimum torque (maximum negative torque) calibrated by the ACC. The second torque relationship is pre-designed in the ACC function through actual vehicle calibration. By obtaining the actual speed of the vehicle, the corresponding ideal torque parameter is found or calculated in the first torque relationship, and the corresponding calibrated torque parameter is found or calculated in the second torque relationship. Compare the ideal torque parameter with the calibrated torque parameter, and take the larger value (smaller absolute value) as the maximum negative torque parameter.

[0096] This embodiment can more accurately control the vehicle's torque output by considering the vehicle's actual speed and ideal torque demand, as well as the actual torque value that can be output, thereby improving driving smoothness and comfort; since the second torque relationship is calibrated based on the actual vehicle, the actual characteristics and conditions of the vehicle are taken into account, making the torque control method more adaptable to the needs of different vehicles and different working conditions; by determining the maximum negative torque parameter, sufficient negative torque can be provided when the vehicle needs to decelerate or brake, thereby maintaining the stability and safety of the vehicle.

[0097] In some embodiments, based on the comparison result of the maximum negative torque parameter and the distributed acceleration, the torque request value of the vehicle drive mechanism and the brake pressure request value of the master cylinder brake mechanism of the vehicle are calculated, including:

[0098] If the allocated acceleration exceeds the acceleration corresponding to the maximum negative torque parameter, the allocated acceleration is allocated to the vehicle drive mechanism to calculate the torque request value;

[0099] On the contrary, the distributed acceleration is distributed to the vehicle drive mechanism and the master cylinder brake mechanism, and the brake pressure request value and the torque request value are calculated based on the distributed acceleration.

[0100] Among them, when the deceleration distribution required is greater than (the absolute value is less than) the maximum deceleration that can be provided by the vehicle drive mechanism alone (that is, the distributed acceleration exceeds the acceleration corresponding to the maximum negative torque parameter), the distributed acceleration is distributed in whole or in part to the vehicle drive mechanism; based on the distributed acceleration, a torque request value is calculated using the conversion relationship between acceleration and torque to drive the vehicle drive mechanism VCU to generate the required braking force. When the deceleration distribution required is less than or equal to the maximum deceleration that can be provided by the vehicle drive mechanism, the distributed acceleration is distributed to the vehicle drive mechanism VCU and the master cylinder brake mechanism EBS, and a torque request value is calculated based on the acceleration portion distributed to the vehicle drive mechanism in combination with the conversion relationship between acceleration and torque, and a brake pressure request value is calculated based on the acceleration portion distributed to the master cylinder brake mechanism in combination with the conversion relationship between acceleration and brake pressure.

[0101] This embodiment reasonably distributes acceleration to the vehicle drive mechanism and the master cylinder brake mechanism, so that it can respond to braking needs more quickly and improve braking performance; when a smaller deceleration is required, it can rely more on the vehicle drive mechanism to make the braking process smoother and more comfortable; and in emergency braking situations, it can fully utilize the maximum braking capacity of the vehicle drive mechanism and the master cylinder brake mechanism to ensure that the vehicle can stop quickly and safely; by reasonably distributing the braking torque, while ensuring braking performance, the additional burden on the engine or motor is minimized, thereby improving energy efficiency.

[0102] In some embodiments, based on the torque request value and the brake pressure request value, the vehicle driving mechanism and the master cylinder brake mechanism are combined to perform a braking operation on the vehicle, including:

[0103] Get real-time vehicle information of the vehicle;

[0104] Calculate the vehicle driving slope value based on real-time vehicle information;

[0105] Calculating a follow-stop pressure request value based on the vehicle driving slope value; wherein the follow-stop pressure request value is used to determine the vehicle braking state;

[0106] The vehicle is braked according to the braking state, the brake pressure request value and the torque request value.

[0107] Among them, the vehicle is equipped with a variety of sensors, which are used to obtain real-time vehicle information of the vehicle, including wheel radius, wheel speed, curb weight, vehicle speed, etc.; using real-time vehicle information, according to the Kalman filter algorithm or other algorithm models, and smoothing filtering, the estimated slope value of the car when driving, that is, the vehicle driving slope value, is calculated in real time; according to the vehicle driving slope value and the vehicle's braking demand (when the vehicle's current speed is low, that is, the vehicle needs to brake smoothly and comfortably in the following stop stage), the following stop pressure request value is calculated through a specific algorithm; the braking control system makes a comprehensive judgment based on the current braking state, braking pressure request value and torque request value and then sends corresponding instructions to the braking actuator to realize the vehicle's braking operation.

[0108] The accurate slope value calculation of this embodiment is helpful for the vehicle's braking control under different road conditions, especially in complex terrains such as uphill and downhill, which can significantly improve the braking effect and safety; the calculation of the follow-stop pressure request value can reflect the pressure demand of the vehicle during the braking process, and provide accurate instructions for subsequent braking operations, thereby improving the response speed and accuracy of the braking system; combined with the precise allocation and control of the braking pressure and torque request values, the stability and safety of the vehicle under different braking requirements are ensured.

[0109] In some embodiments, a braking operation is performed on a vehicle according to a braking state of the vehicle, a brake pressure request value, and a torque request value, including:

[0110] The vehicle braking state includes driving state and following stop state;

[0111] If the vehicle braking state is the driving state, a braking operation is performed on the vehicle based on the torque request value and the brake pressure request value;

[0112] If the vehicle braking state is the follow-stop state, the brake pressure request value is updated based on the follow-stop pressure request value to obtain an updated pressure request value, and the vehicle is braked according to the updated pressure request value.

[0113] The following stop state refers to the state in which the vehicle starts and stops following the vehicle in front while maintaining a certain safe distance from the vehicle in front during driving. The following stop pressure request value is calculated based on the real-time vehicle information and the vehicle driving slope value; the following stop pressure request value is used as an important basis for judging whether the vehicle enters the following stop state; if the vehicle braking state is judged to be the driving state, the braking operation logic in the driving state is executed, and the vehicle drive mechanism VCU brakes the vehicle according to the torque request value and the master cylinder brake mechanism EBS brakes the vehicle according to the brake pressure request value; if the vehicle braking state is judged to be the following stop state, the braking operation logic in the following stop state is executed, and the brake pressure request value is updated based on the following stop pressure request value to obtain the updated pressure request value, and the master cylinder brake mechanism EBS is instructed to brake the vehicle according to the updated pressure request value, and the vehicle braking system VCU is not needed at this time.

[0114] It should be understood that in addition to the above-mentioned two vehicle braking states of driving state and following stop state, the vehicle driving state of starting state can also be included. If it is detected that the vehicle changes from the vehicle braking state of following stop state to the starting state, the updated pressure request value is reduced to the preset pressure request value, and the driving torque value of the vehicle driving mechanism is obtained, and finally the vehicle is driven according to the driving torque value and the preset pressure value. It should also be understood that the preset pressure request value can be set in advance according to actual conditions. For example, the preset pressure request value can be set to 0. In this case, it means that as it is detected that the vehicle changes from the vehicle braking state of following stop state to the starting state, the pressure value of the master cylinder brake mechanism can be reduced to 0 based on the above method, and the master cylinder brake mechanism does not need to participate in the control operation of the starting state.

[0115] This embodiment can more effectively control the braking behavior of the vehicle by accurately judging the braking state of the vehicle, thereby improving driving safety and riding comfort; in the driving state, that is, the vehicle speed is fast, it can perform precise braking operations based on the torque request value and the brake pressure request value, and at the same time, use the vehicle braking system VCU and the master cylinder brake mechanism EBS to brake the vehicle to meet the braking needs during normal driving; in the follow-stop state, that is, the vehicle speed is slow, it can update the brake pressure request value based on the follow-stop pressure request value, and only use the master cylinder brake mechanism EBS to brake the vehicle, thereby more accurately controlling the vehicle's braking pressure and avoiding excessive or insufficient braking, helping to reduce the braking shock and shaking of the vehicle, improving riding comfort, helping to ensure that the vehicle can stably stop and remain stationary in the follow-stop state, and improving driving safety.

[0116] The embodiments of the present application are described and illustrated below through preferred embodiments.

[0117] Figure 3is a system architecture diagram of the ACC function of the longitudinal control method of the vehicle according to the preferred embodiment of the present application, such as Figure 3 As shown:

[0118] ACC upper controller: a part of the ADAS controller. When the ACC function is activated, it receives the information of the front vehicle target, lane line, etc. output by the sensing end, and calculates the target acceleration of the ACC function in real time based on the motion state of the vehicle, and outputs it to the VLC module (ACC lower controller);

[0119] VLC module (ACC lower controller): a part of the ADAS controller. After receiving the target acceleration of the vehicle output by the ACC upper controller, the VLC module calculates and distributes the target torque (positive or negative, in Newton meters, N·m) to be sent to the VCU and the target master cylinder pressure (greater than 0, in bar) to be sent to the EBS in real time according to the information such as the vehicle speed, vehicle acceleration, and wheel speed provided by the ESC.

[0120] EBS (Electronic Brake Booster): When the ACC function is activated, it receives the target master cylinder pressure output by the VLC module, performs servo control through the actuator, and outputs the hydraulic pressure to the brake system, thereby affecting the movement state of the entire vehicle;

[0121] VCU (Vehicle Controller): When the ACC function is activated, it receives the target torque output by the VLC module, performs servo control through the actuator, and outputs the torque to the drive system, thereby affecting the movement state of the entire vehicle.

[0122] Figure 4 is a VLC module system architecture diagram of the longitudinal control method of a vehicle according to an embodiment of the present application, such as Figure 4 As shown, it includes five modules: road load estimation module, PID+feedforward controller module, VLC driving torque distribution module, VLC follow-stop pressure maintenance calculation module, and VLC driving / follow-stop start state machine. The specific contents are as follows:

[0123] Road Load Estimation Module:

[0124] The input of this module is the acceleration sensor value (including the slope component) provided by ESC, wheel speed, vehicle speed, vehicle curb weight, wheel radius and other information. According to the Kalman filter algorithm and first-order smoothing filter, this logic outputs the actual acceleration of the vehicle (slope component removed) and the slope estimation value. In addition, the module estimates the vehicle's driving resistance (rolling resistance and air resistance, actual vehicle calibration) based on the vehicle speed; at the same time, according to the aforementioned estimated slope component, the slope resistance of the vehicle is calculated. The above three resistances are added together to obtain the road load estimation value and output it.

[0125] ① According to the Kalman filter algorithm, smoothing filtering is performed to calculate the estimated slope of the car in real time and output it.

[0126] ② Based on the estimated slope value and the ESC acceleration sensor value, the actual acceleration of the vehicle after removing the slope component can be obtained and output according to the following formula:

[0127] a actual =a esc +gsinθ (1)

[0128] in, aactual is the actual acceleration of the vehicle (excluding the slope component); aesc is the acceleration sensor value (including the slope component); g is the gravity acceleration, which is 9.8m / s 2 ; θ is the slope, where upslope is defined as negative and downslope is defined as positive.

[0129] ③The module also estimates the vehicle's driving resistance and slope resistance to obtain a road load estimate.

[0130] The theoretical value of the driving resistance of a car is:

[0131]

[0132] Among them, F f is the estimated sum of rolling resistance and air resistance; m is the vehicle's curb weight; g is the acceleration due to gravity, which is 9.8 m / s 2 ; f is the rolling resistance coefficient; ρ is the air density; A is the frontal area of ​​the car; C d is the air resistance coefficient; v is the vehicle speed.

[0133] In actual engineering, the actual vehicle calibration will be fine-tuned based on the above theoretical values ​​to adapt to the project.

[0134] The slope resistance of the car is:

[0135] F i =-mgsinθ (3)

[0136] Among them, F i is the slope resistance; m is the vehicle's curb weight; g is the acceleration due to gravity, which is 9.8 m / s 2 ; θ is the slope, where upslope is defined as negative and downslope is defined as positive.

[0137] The road load is the sum of the driving resistance and the slope resistance mentioned above, which is output for subsequent module calculations.

[0138] PID+Feedforward Controller Module:

[0139] This module is mainly aimed at driving conditions, including feedforward and feedback (PID) 2 part controllers. This module outputs the VLC internal target acceleration (torque), which is the distribution acceleration in the above embodiment. The dimensions of torque and master cylinder pressure are different in the subsequent logic. For the convenience of processing, this module uniformly processes them according to the acceleration dimension.

[0140] ① The feedforward part eliminates the deceleration caused by the estimated load based on the target acceleration output by the original ACC (for example, the target acceleration output by the ACC upper controller is +2m / s 2 , the acceleration generated by the load is estimated to be -0.2m / s 2 , then the feedforward acceleration is +2.2m / s 2 ). Based on formula (2)-(3), the calculation formula is:

[0141]

[0142] Among them, a ff is the feedforward acceleration output; a req is the ACC target acceleration; F f is the estimated sum of rolling resistance and air resistance; m is the vehicle's curb weight; g is the acceleration due to gravity, which is 9.8 m / s 2 ; θ is the slope, where upslope is defined as negative and downslope is defined as positive.

[0143] After the feedforward acceleration is calculated, smoothing filtering is performed as the final output.

[0144] ②PID feedback part is based on the difference between the target acceleration output by ACC and the actual acceleration of the vehicle, and according to the PID algorithm, calculates the acceleration component of the feedback part. The calculation formula is:

[0145] a pid =K p (a req -a actual )+K i ∫(a req -a actual )dt (5)

[0146] Among them, a pid is the feedback acceleration output; a req is the ACC target acceleration; a actual is the actual acceleration of the vehicle (excluding the slope component); K p is the proportionality coefficient; K i is the integration coefficient.

[0147] After the feedback acceleration is calculated, smoothing filtering is performed as the final output.

[0148] ③ Add the two accelerations of feedforward and feedback to get the final VLC internal target acceleration, which is used as the torque distribution logic input for driving conditions in subsequent modules. That is:

[0149] a VLC =a ff +a pid (6)

[0150] Among them, a VLC is the internal target acceleration of VLC; a ff is the feedforward acceleration; a pid is the feedback acceleration.

[0151] VLC driving torque distribution module:

[0152] ①Torque distribution is to convert the output of the previous module into VLC (VLC internal target acceleration) is decomposed into torque request T VLC and the master cylinder pressure request p VLC .

[0153] VLC internal target acceleration a VLC It consists of two components: torque request component a T and hydraulic request component a p ,Right now:

[0154] a VLC =a T +a p (7)

[0155] Torque request component a T With torque request T VLC The relationship is:

[0156] T VLC =ma T R (8)

[0157] Among them, T VLC is the torque request; m is the vehicle's curb weight; a T is the torque request component; R is the wheel radius.

[0158] Hydraulic request component a p With master cylinder pressure request p VLC The relationship is:

[0159] p VLC =-Ka p (9)

[0160] Among them, p VLC The main cylinder pressure request, ≥0, unit bar; a p is the hydraulic request component; K is the master cylinder pressure conversion coefficient.

[0161] The value of K is generally adjusted appropriately based on the actual vehicle calibration on the basis of the theoretical value.

[0162] The theoretical value of K can generally be calculated by the following formula (the units of all physical quantities are in the International System of Units):

[0163]

[0164] Among them, m is the curb weight of the vehicle itself; R is the wheel radius; R brake is the effective braking radius of the brake; μ is the friction coefficient of the brake pad; D f is the cylinder diameter of the front wheel piston; D r is the cylinder diameter of the rear wheel piston.

[0165] ② Torque request T VLC is calculated as follows:

[0166] When torque is distributed, the minimum torque (maximum negative torque) T minVcu available at the wheel end that can be used by the VCU is given priority.

[0167] This value is related to the energy recovery strategy of the VCU. Generally speaking, if the vehicle speed of the vehicle itself is v, then there is:

[0168] T minVcu = f(v)(T minVcu ≤ 0)(11)

[0169] The look-up table function f(v) is generally provided by the VCU supplier and represents the maximum negative torque that the VCU can use.

[0170] ③ Figure 5 is the ACC negative torque design function relationship diagram of the longitudinal control method of the vehicle according to the embodiment of the present application. In the ACC negative torque design, assuming that the maximum value (absolute value) of the ACC target negative torque is output as T negtar , a design method similar to Figure 5 shown is used:

[0171] When the vehicle speed v of the vehicle itself ≤ v1, T negtar = 0;

[0172] When the vehicle speed v of the vehicle itself satisfies v1 < v < v2, T negtar = g(v), which is confirmed by linear interpolation or actual vehicle calibration;

[0173] When the vehicle speed v of the vehicle itself ≥ v2, T negtar = T minacc .

[0174] ④ The above calibration values v1, v2, T minacc will be considered in combination with Equation (11). Thus, for a certain moment when the vehicle speed is v, the torque request TVLC Need to meet:

[0175] T VLC ≥max(T negtar , T minVcu )(12)

[0176] Combining equation (8), we have:

[0177]

[0178] The specific allocation process considers formula (7) again:

[0179] like Then a T =a VLC ; a p =0;

[0180] like but a p =

[0181] a VLC -a T ;

[0182] The above results combined with equations (8)-(9) can be obtained to obtain the torque request T at each moment: VLC and the master cylinder pressure request p VLC .

[0183] The more typical ACC driving scenarios are shown in the table below (for ease of understanding, large slopes are not considered, and the parameter convergence of the feedback system is not considered).

[0184]

[0185] T VLC With p VLC The output is sent to the subsequent VLC driving / stop-and-start state machine as the input of this module.

[0186] VLC follow-stop pressure-maintaining calculation module:

[0187] In the following stop phase, in order to prevent the car from sliding down the slope, ACC needs to request EBS to build up the master cylinder pressure to maintain stability (without making torque request to VCU). ACC requests EBS the master cylinder pressure target value p standstill It is related to the slope size θ. The general principle is that the maximum static friction force of the vehicle that can be generated by the master cylinder pressure needs to exceed the gravity component of the vehicle in the slope direction, and there is a certain redundancy. Use the following formula to calculate:

[0188] p standstill =S(θ)·K·g·|sinθ|+K0(14)

[0189] Among them, p standstill is the master cylinder pressure request value when ACC stops, in bar; S(θ) is the safety factor, which is appropriately enlarged when θ is small according to the slope table, and calibrated on the actual vehicle; K is the master cylinder pressure conversion coefficient; g is the acceleration of gravity, which is taken as 9.8m / s 2 ; θ is the slope, which is defined as negative for uphill and positive for downhill; K0 is the flat road pressure maintenance request value (safety redundancy), which is calibrated by the actual vehicle.

[0190] The output is sent to the subsequent VLC driving / stop-and-start state machine as the input of this module.

[0191] VLC driving / stop-and-start state machine:

[0192] This module receives the torque request T during ACC driving. VLC , master cylinder pressure request p VLC , ACC master cylinder pressure request p standstill In addition, it also receives several signals from the ACC upper controller (such as ACC internal deceleration to stop request, ACC internal departure request, etc.) for the logic processing of the VLC state machine.

[0193] Figure 6 is a schematic diagram of the state machine jump of the longitudinal control method of the vehicle according to the embodiment of the present application. The schematic diagram of the state machine jump is as follows Figure 6 As shown, there are 5 states in total.

[0194] exist Figure 6 In the different states shown, the master cylinder pressure request value output by the VLC module to the EBS and the torque request value of the VCU are shown in the table below.

[0195]

[0196]

[0197] Figure 7 is a flow chart of another longitudinal control method of a vehicle according to an embodiment of the present application, such as Figure 7 As shown, the preferred embodiment designs negative torque logic: the ADAS end completes the distribution of torque and hydraulic pressure, and converts the hydraulic request into the master cylinder pressure dimension; the VLC driving / following stop state jump logic is designed: the ADAS end completes the connection processing between normal driving and following stop, and realizes the logic of the ADAS end controlling the entire driving and following stop process.

[0198] It should be noted that in actual applications, the above VLC request values ​​for EBS and VCU will be modified based on actual engineering conditions.

[0199] This embodiment also provides a vehicle, the vehicle comprising a vehicle drive mechanism, a master cylinder brake mechanism and a controller;

[0200] The controller includes a memory and a processor. The memory stores a computer program. The processor is configured to run the computer program to execute the steps in any one of the above method embodiments.

[0201] In addition, in combination with the longitudinal control method of the vehicle in the above embodiments, the embodiment of the present application can provide a storage medium for implementation. The storage medium stores a computer program; when the computer program is executed by a processor, any longitudinal control method of the vehicle in the above embodiments is implemented.

[0202] Those skilled in the art should understand that the technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0203] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A longitudinal control method for a vehicle, characterized in that: include: Obtain the preset target acceleration and calculate the actual acceleration of the vehicle; Calculating a distributed acceleration based on the target acceleration and the actual acceleration of the vehicle; Obtaining a maximum negative torque parameter of a vehicle drive mechanism of the vehicle; Calculating a torque request value of the vehicle drive mechanism and a brake pressure request value of the master cylinder brake mechanism of the vehicle based on a comparison result of the maximum negative torque parameter and the distributed acceleration; Based on the torque request value and the brake pressure request value, the vehicle driving mechanism and the master cylinder brake mechanism are combined to perform a braking operation on the vehicle.

2. The longitudinal control method of a vehicle according to claim 1, characterized in that: The calculating the distribution acceleration based on the target acceleration and the actual acceleration of the vehicle comprises: Get vehicle load value; Based on the target acceleration, the vehicle load value, and the vehicle actual acceleration, a distributed acceleration is calculated.

3. The longitudinal control method of a vehicle according to claim 2, characterized in that: The obtaining of the vehicle load value comprises: Acquiring real-time vehicle information of the vehicle; Based on the real-time vehicle information, a vehicle running resistance and a vehicle slope resistance are calculated, and based on the vehicle running resistance and the vehicle slope resistance, the vehicle load value is acquired.

4. The longitudinal control method of a vehicle according to claim 2, characterized in that: The calculating the distribution acceleration based on the target acceleration, the vehicle load value and the actual acceleration of the vehicle comprises: calculating a feedforward acceleration based on the target acceleration and the vehicle load value; calculating a feedback acceleration based on a difference between the target acceleration and the actual acceleration of the vehicle; The distributed acceleration is calculated based on the feedforward acceleration and the feedback acceleration.

5. The longitudinal control method of a vehicle according to claim 1, characterized in that: The obtaining of the maximum negative torque parameter of the vehicle drive mechanism includes: Acquire a preset first torque relationship, where the first torque relationship is used to indicate a mapping relationship between a vehicle speed and an ideal torque value; determining an ideal torque parameter corresponding to an actual vehicle speed of the vehicle based on the first torque relationship; Acquire a second torque relationship calibrated for the actual vehicle, where the second torque relationship is used to indicate a mapping relationship between a vehicle speed and a calibrated torque value; determining a calibrated torque parameter corresponding to the actual vehicle speed based on the second torque relationship; The maximum negative torque parameter is determined based on the ideal torque parameter and the calibrated torque parameter.

6. The longitudinal control method of a vehicle according to claim 1, characterized in that: The step of calculating the torque request value of the vehicle drive mechanism and the brake pressure request value of the master cylinder brake mechanism of the vehicle based on the comparison result of the maximum negative torque parameter and the distributed acceleration includes: If the distributed acceleration exceeds the acceleration corresponding to the maximum negative torque parameter, the distributed acceleration is distributed to the vehicle drive mechanism to calculate the torque request value; On the contrary, the distributed acceleration is distributed to the whole vehicle driving mechanism and the master cylinder brake mechanism, and the brake pressure request value and the torque request value are calculated based on the distributed acceleration.

7. The longitudinal control method of a vehicle according to claim 1, characterized in that: The method of performing a braking operation on the vehicle based on the torque request value and the brake pressure request value in combination with the vehicle drive mechanism and the master cylinder brake mechanism includes: Acquiring real-time vehicle information of the vehicle; Calculating a vehicle driving slope value based on the real-time vehicle information; Calculating a follow-stop pressure request value based on the vehicle driving slope value; wherein the follow-stop pressure request value is used to determine the braking state of the vehicle; A braking operation is performed on the vehicle according to the vehicle braking state, the brake pressure request value, and the torque request value.

8. The longitudinal control method of a vehicle according to claim 7, characterized in that: The step of performing a braking operation on the vehicle according to the vehicle braking state, the brake pressure request value and the torque request value comprises: The vehicle braking state includes a driving state and a following parking state; If the vehicle braking state is the driving state, performing a braking operation on the vehicle based on a torque request value and a brake pressure request value; If the vehicle braking state is the follow-stop state, the brake pressure request value is updated based on the follow-stop pressure request value to obtain an updated pressure request value, and a braking operation is performed on the vehicle according to the updated pressure request value.

9. A vehicle, characterized in that: The vehicle comprises a vehicle drive mechanism, a master cylinder brake mechanism and a controller; The controller includes a memory and a processor. The memory stores a computer program. The processor is configured to run the computer program to execute the longitudinal control method of a vehicle according to any one of claims 1 to 8.

10. A storage medium, characterized in that: The storage medium stores a computer program, wherein the computer program is configured to execute the longitudinal control method of a vehicle according to any one of claims 1 to 8 when executed.

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