Comfort braking method based on longitudinal and vertical fusion technology of chassis domain controller

Abstract

The present invention discloses a comfortable braking method based on the longitudinal and vertical fusion technology of the chassis domain controller, which belongs to the field of vehicle braking and includes the following steps: S1, data acquisition; S2, data analysis: determining the change in vehicle suspension stiffness and activation duration; S3, dividing the change in vehicle suspension stiffness and activation duration into multiple adjustment levels; S4, test verification. The present invention adopts the above-mentioned comfortable braking method based on the longitudinal and vertical fusion technology of the chassis domain controller, combines the longitudinal and vertical technologies of the chassis domain, and adjusts the suspension system based on the detection of real-time vehicle conditions, so as to prevent target loss, increase driving comfort and the robustness of system target recognition.

Description

Technical Field

[0001] The invention relates to the field of vehicle braking, and in particular to a comfortable braking method based on a chassis domain controller longitudinal and vertical fusion technology. Background Art

[0002] In the process of achieving efficient operation of the automatic emergency braking (AEB) system, it is crucial to accurately control the braking torque to match the real-time road conditions. Based on this, the existing technology makes full use of the advanced sensor technology installed on the front of the vehicle. The above sensors are like the "eyes" of the vehicle, continuously monitoring the surrounding environment, from the slippery degree of the road to the sudden obstacles. The capture of every bit of road condition information is a meticulous consideration for driving safety. Through the real-time analysis of these data, the system can dynamically adjust the degree of emergency braking intervention, thereby avoiding the discomfort caused by excessive braking and preventing the risks caused by insufficient braking, and realizing intelligent management of emergency response.

[0003] However, at the critical moment of emergency braking, the vehicle is affected by strong deceleration, causing the mass distribution to concentrate forward, inducing a dynamic phenomenon called "nodding" - the front of the vehicle sinks sharply. This sudden change not only instantly increases the direct impact on the driver's body, causing discomfort and even potential driving interference, but also poses a severe test to the sensor system that relies on accurate visual feedback. That is, when the front of the vehicle drops sharply, the sensor's field of view may be instantly changed or temporarily blocked, resulting in damage to the continuity and accuracy of road condition monitoring, which may weaken the accuracy and efficiency of emergency braking intervention and affect the ability of the entire AEB system to respond to emergencies. Summary of the invention

[0004] In order to solve the problem of sensor target loss caused by the violent pitch of the front of the vehicle during the current AEB braking process, the present invention provides a comfortable braking method based on the longitudinal and vertical fusion technology of the chassis domain controller, comprising the following steps:

[0005] S1. Data collection: Collect vehicle state parameters when the vehicle stops in emergency under various driving conditions, where the vehicle state parameters include vehicle suspension stiffness, longitudinal deceleration during braking, vehicle speed, vehicle pitch angle, maximum duration, target loss, and comfort value;

[0006] S2, data analysis: searching for longitudinal deceleration during braking under various driving conditions described in step S1, changes in comfort value, changes in vehicle pitch angle, changes in vehicle suspension stiffness, and target loss, and determining the vehicle suspension stiffness change and activation duration with the highest comfort value, no target loss, and the smallest vehicle pitch angle change as the goal;

[0007] S3, dividing the vehicle suspension stiffness change and activation duration into multiple adjustment levels under various driving conditions;

[0008] S4, test verification: determine the adjustment level according to the vehicle's driving condition and the longitudinal deceleration and speed collected during the vehicle's driving process, and adjust the vehicle suspension stiffness according to the adjustment level. At the same time, determine whether the adjusted comfort value is within the set range, whether the vehicle pitch angle change is within the set range, and whether the target is lost. If the adjusted comfort value and the vehicle pitch angle change are both within the set range and the target is not lost, the verification is passed, otherwise return to step S2.

[0009] Preferably, in step S1, the multiple driving conditions include multiple test road conditions and multiple test vehicle conditions respectively tested on the multiple test road conditions, wherein the multiple test road conditions include a road with a high adhesion coefficient and a road with a low adhesion coefficient, or the multiple test road conditions include a smooth road surface and a gravel road surface; the test vehicle conditions include an empty vehicle state and a fully loaded vehicle state;

[0010] The comfort value is obtained by the driver's subjective scoring under various driving conditions.

[0011] Preferably, step S2 specifically includes the following steps:

[0012] S21. Determine a comparison scenario: compare the same test vehicle condition on a road with a high adhesion coefficient and a road with a low adhesion coefficient, or compare the same test vehicle condition on a smooth road and a gravel road;

[0013] And compare the empty state of the vehicle and the fully loaded state of the vehicle under the same test road conditions;

[0014] S22, obtaining the longitudinal deceleration of the vehicle within the threshold range and the pitch angle change of the vehicle under the condition of vehicle speed change under the comparison scenario determined in step S21, and obtaining the relationship between the pitch angle change of the vehicle and the target loss condition, the comfort value change, and the vehicle suspension stiffness change;

[0015] S23, determining the change in vehicle suspension stiffness and activation duration with the goal of achieving the highest comfort value, not losing the target, and minimizing the change in the vehicle pitch angle.

[0016] Preferably, in step S23, when the vehicle brakes at a deceleration and speed within a threshold range, the pitch angle size and duration of the vehicle are predicted based on the relationship between the vehicle longitudinal deceleration, speed change and vehicle pitch angle change obtained in step S22; when the vehicle pitch angle change reaches an upper limit, a signal is sent to the vehicle suspension system to increase the vehicle suspension stiffness; and when the longest duration reaches the theoretical duration of the pitch, the stiffness of the vehicle suspension system is reduced.

[0017] Preferably, in step S3, the adjustment level is determined according to the collected deceleration and vehicle speed, and sent to the chassis domain controller, and the chassis domain controller adjusts the stiffness of the vehicle suspension system according to the received adjustment level.

[0018] The present invention has the following beneficial effects:

[0019] The chassis domain controller analyzes the current road conditions, determines the adjustment level, and sends the corresponding adjustment level to the suspension system. The suspension system then obtains the corresponding adjustment plan based on the obtained adjustment level, selects the corresponding parameters to gradually adjust the suspension stiffness, reduce the pitch change of the vehicle body, and increase the robustness of the perception system's target recognition and driving comfort.

[0020] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a flow chart of the comfortable braking method based on the longitudinal and vertical fusion technology of the chassis domain controller of the present invention. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical scheme and advantages disclosed in the embodiments of the present invention clearer, the embodiments of the present invention are further described in detail in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the embodiments of the present invention and are not intended to limit the embodiments of the present invention. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions.

[0023] It should be noted that the terms "include", "have" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or server comprising a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to these processes, methods, products or devices.

[0024] Like reference numerals and letters denote similar items in the following drawings, and thus, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0025] like Figure 1 As shown, a comfortable braking method based on the longitudinal and vertical fusion technology of the chassis domain controller includes the following steps:

[0026] S1. Data collection: Collect vehicle state parameters when the vehicle stops in emergency under various driving conditions, where the vehicle state parameters include vehicle suspension stiffness, longitudinal deceleration during braking, vehicle speed, maximum duration, vehicle pitch angle, target loss, and comfort value;

[0027] In step S1, the multiple driving conditions include multiple test road conditions and multiple test vehicle conditions respectively tested on the multiple test road conditions, wherein the multiple test road conditions include a road with a high adhesion coefficient and a road with a low adhesion coefficient, or the multiple test road conditions include a smooth road surface and a gravel road surface; the test vehicle conditions include an empty vehicle state and a fully loaded vehicle state;

[0028] The comfort value is obtained by subjective scoring by the driver under various driving conditions. A higher suspension stiffness can keep the vehicle body stable and reduce the pitch of the front of the vehicle; a lower suspension stiffness can provide a softer riding experience and reduce the impact of road bumps. Based on this, the driver judges the comfort by subjectively feeling whether the front of the vehicle pitches severely and whether the bumps are severe, and thus determines whether to adjust the suspension stiffness.

[0029] S2, data analysis: searching for longitudinal deceleration during braking under various driving conditions described in step S1, changes in comfort value, changes in vehicle pitch angle, changes in vehicle suspension stiffness, and target loss, and determining the vehicle suspension stiffness change and activation duration with the highest comfort value, no target loss, and the smallest vehicle pitch angle change as the goal;

[0030] Step S2 specifically includes the following steps:

[0031] S21. Determine a comparison scenario: compare the same test vehicle condition on a road with a high adhesion coefficient and a road with a low adhesion coefficient, or compare the same test vehicle condition on a smooth road and a gravel road;

[0032] And compare the empty state of the vehicle and the fully loaded state of the vehicle under the same test road conditions;

[0033] S22, obtaining the longitudinal deceleration of the vehicle within the threshold range and the pitch angle change of the vehicle under the condition of vehicle speed change under the comparison scenario determined in step S21, and obtaining the relationship between the pitch angle change of the vehicle and the target loss condition, the comfort value change, and the vehicle suspension stiffness change;

[0034] S23, determining the change in vehicle suspension stiffness and activation duration with the goal of achieving the highest comfort value, not losing the target, and minimizing the change in the vehicle pitch angle.

[0035] In step S23, within the threshold range (in this embodiment, the vehicle speed range during emergency braking is 4km / h-90km / h, and the deceleration does not exceed 10m / s2 ) when the vehicle brakes, the pitch angle size and duration of the vehicle are predicted according to the relationship between the vehicle longitudinal deceleration, vehicle speed change and vehicle pitch angle change obtained in step S22; when the vehicle pitch angle change reaches an upper limit, a signal is sent to the vehicle suspension system to increase the vehicle suspension stiffness; and when the longest duration reaches the theoretical duration of the pitch, the stiffness of the vehicle suspension system is reduced.

[0036] S3, dividing the vehicle suspension stiffness change and activation duration into multiple adjustment levels under various driving conditions;

[0037] In step S3, the adjustment level is determined according to the collected deceleration and vehicle speed, and sent to the chassis domain controller, and the chassis domain controller adjusts the stiffness of the vehicle suspension system according to the received adjustment level.

[0038] In this embodiment, under the premise that the required adjustment range of the suspension system stiffness and the specific change demand relationship of the activation time under different test conditions have been clarified, multiple different adjustment levels are defined based on the magnitude of the suspension stiffness change and the length of the activation duration. The division principle is: the greater the increase or decrease of the suspension stiffness, or the longer the activation time, the higher the corresponding adjustment level is set, and vice versa. Then, from the suspension stiffness change and activation time range defined by the level, a group of combinations of suspension stiffness change and activation time that best reflect the characteristics of the level is selected as the actual operation benchmark of the adjustment level, based on which feedback adjustment of the level is realized.

[0039] S4, test verification: determine the adjustment level according to the vehicle's driving condition and the longitudinal deceleration and speed collected during the vehicle's driving process, and adjust the vehicle suspension stiffness according to the adjustment level. At the same time, determine whether the adjusted comfort value is within the set range, whether the vehicle pitch angle change is within the set range, and whether the target is lost. If the adjusted comfort value and the vehicle pitch angle change are both within the set range and the target is not lost, the verification is passed, otherwise return to step S2.

[0040] Therefore, the present invention adopts the above-mentioned comfortable braking method based on the longitudinal and vertical fusion technology of the chassis domain controller. By combining the longitudinal and vertical technologies of the chassis domain and based on detecting the real-time vehicle condition, the suspension system is adjusted to prevent target loss, increase driving comfort and the robustness of system target recognition.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A comfortable braking method based on chassis domain controller longitudinal and vertical fusion technology, characterized in that: The following steps are involved: S1. Data collection: Collect vehicle state parameters when the vehicle stops in emergency under various driving conditions, where the vehicle state parameters include vehicle suspension stiffness, longitudinal deceleration during braking, vehicle speed, vehicle pitch angle, maximum duration, target loss, and comfort value; S2, data analysis: searching for longitudinal deceleration during braking under various driving conditions described in step S1, changes in comfort value, changes in vehicle pitch angle, changes in vehicle suspension stiffness, and target loss, and determining the vehicle suspension stiffness change and activation duration with the highest comfort value, no target loss, and the smallest vehicle pitch angle change as the goal; Step S2 specifically includes the following steps: S21. Determine a comparison scenario: compare the same test vehicle condition on a road with a high adhesion coefficient and a road with a low adhesion coefficient, or compare the same test vehicle condition on a smooth road and a gravel road; And compare the empty state of the vehicle and the fully loaded state of the vehicle under the same test road conditions; S22, obtaining the longitudinal deceleration of the vehicle within the threshold range and the pitch angle change of the vehicle under the condition of vehicle speed change under the comparison scenario determined in step S21, and obtaining the relationship between the pitch angle change of the vehicle and the target loss condition, the comfort value change, and the vehicle suspension stiffness change; S23, determining the change amount of the vehicle suspension stiffness and activation duration with the highest comfort value, no target loss, and the smallest change in the vehicle pitch angle as the goal; In step S23, when the vehicle with longitudinal deceleration and speed change within the threshold range brakes, the pitch angle size and theoretical duration of the vehicle are predicted according to the relationship between the longitudinal deceleration of the vehicle, the speed change and the pitch angle change of the vehicle obtained in step S22, and when the pitch angle change of the vehicle reaches the upper limit of the pitch angle change of the vehicle, a signal is sent to the vehicle suspension system to increase the stiffness of the vehicle suspension, and when the longest duration reaches the theoretical duration of the pitch, the stiffness of the vehicle suspension system is reduced; S3, dividing the vehicle suspension stiffness change and activation duration into multiple adjustment levels under various driving conditions; S4, test verification: adjust the vehicle suspension stiffness according to the adjustment level, and determine whether the adjusted comfort value is within the set range, whether the vehicle pitch angle change is within the set range, and whether the target is lost. If the adjusted comfort value and the vehicle pitch angle change are both within the set range and the target is not lost, the verification is passed, otherwise return to step S2.

2. The comfortable braking method based on the longitudinal and vertical fusion technology of the chassis domain controller according to claim 1 is characterized in that: In step S1, the multiple driving conditions include multiple test road conditions and multiple test vehicle conditions respectively tested on the multiple test road conditions, wherein the multiple test road conditions include a road with a high adhesion coefficient and a road with a low adhesion coefficient, or the multiple test road conditions include a smooth road surface and a gravel road surface; the test vehicle conditions include an empty vehicle state and a fully loaded vehicle state; The comfort value is obtained by the driver's subjective scoring under various driving conditions.

3. The comfortable braking method based on the longitudinal and vertical fusion technology of the chassis domain controller according to claim 2 is characterized in that: In step S3, the adjustment level is determined according to the collected deceleration and vehicle speed, and sent to the chassis domain controller, and the chassis domain controller adjusts the stiffness of the vehicle suspension system according to the received adjustment level.

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