Limit stroke identification method, device, equipment, medium and program for vehicle suspension

Abstract

The invention relates to the technical field of vehicle control, and discloses a limit stroke identification method, device and equipment of a vehicle suspension, a medium and a program, and the roughness and the type of a road surface on which a vehicle runs are determined through a sprung acceleration signal and an unsprung acceleration signal of the suspension. Then, according to the driving mode of the vehicle, the vehicle speed, the roughness of the road surface and the type of the road surface, selecting an acceleration change rate threshold value and a limit difference threshold value which are more adaptive to the working condition of the vehicle; therefore, when the limit stroke identification is carried out according to the acceleration change rate threshold and the limit difference threshold, the actual state of the vehicle and the actual working condition of the vehicle are better matched, and the accuracy of the limit stroke identification is improved. When it is detected that the acceleration change rate is larger than the acceleration change rate threshold value or the limit difference value is larger than the limit difference threshold value, it can be determined that the vehicle suspension enters the limit stroke, damping of a shock absorber can be adjusted timely and accurately, and the vehicle comfort is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicle control, in particular to a limit travel recognition method, device, equipment, medium and program of a vehicle suspension. BACKGROUND

[0002] With the popular wave of automobile electrification and intelligentization, the installation quantity of electric control suspension systems has increased sharply, and the price range of the vehicle models has been continuously lowered. The electric control suspension system has become a key technology of the chassis which is widely used. The electronic continuous damping control suspension system (ECDC) monitors the information such as the vehicle body posture, wheel movement and road conditions in real time through an electronic control system and sensors, calculates the damping force required by the current vehicle, and then quickly adjusts the damper damping to improve the comfort of the vehicle. The suspension limit travel (also known as the end travel) refers to the last section of travel when the damper is compressed or stretched, i.e. reaching its physical limit (reaching the compression point or the limit of the stretching position). When the suspension reaches the limit travel, it will be accompanied by a huge impact and abnormal noise, and the passengers will feel severe jolting, which greatly affects the comfort.

[0003] The prior art usually judges whether the suspension travel information reaches the limit value according to the sensor signal on the suspension, detects whether the suspension enters the limit travel, and adjusts the damper damping based on the limit travel. The prior art also judges whether the vehicle is in the limit travel range according to the height sensor signal, so as to calculate the target damping force of the suspension when the vehicle reaches the limit travel range.

[0004] The above scheme focuses on how to control the damper damping force after recognizing that the suspension is in the limit travel, and the limit value and the limit travel range are preset values. However, when the limit travel is detected according to the preset value, since the preset value does not match the actual vehicle working condition, the suspension entering the limit travel is not recognized or is incorrectly recognized, which leads to the damper damping not being adjusted in time or being incorrectly adjusted, and thus abnormal noise is easily generated on the actual vehicle, causing discomfort to the user. SUMMARY

[0005] The present application provides a limit travel recognition method, device, equipment, medium and program of a vehicle suspension, to solve the problem that the prior art cannot accurately recognize whether the suspension enters the limit travel.

[0006] In a first aspect, the present application provides a limit travel recognition method of a vehicle suspension, which comprises: obtaining the driving mode, vehicle speed, spring-on acceleration signal and spring-down acceleration signal of the suspension of the vehicle; determining the roughness of the vehicle driving road surface and the movement direction of the damper on the suspension relative to the vehicle body based on the spring-on acceleration signal and the spring-down acceleration signal; determining a limit difference value and an acceleration change rate of the unsprung acceleration signal, and determining a road surface type of a driving road surface of the vehicle based on a motion direction and the acceleration change rate; obtaining an acceleration change rate threshold value and a limit difference threshold value according to a driving mode, a vehicle speed, a roughness and the road surface type of the driving road surface of the vehicle; determining that the suspension of the vehicle enters a limit travel when it is detected that the acceleration change rate is greater than the acceleration change rate threshold value, or the limit difference value is greater than the limit difference threshold value.

[0007] The present application determines the roughness and the road surface type of the driving road surface of the vehicle through the sprung acceleration signal and the unsprung acceleration signal of the suspension. Then, the acceleration change rate threshold value and the limit difference threshold value that are more suitable for the working condition of the vehicle are selected according to the driving mode, the vehicle speed, the roughness and the road surface type of the road surface. Thus, when the limit travel is identified according to the acceleration change rate threshold value and the limit difference threshold value, it is more consistent with the actual state of the vehicle and the actual working condition of the vehicle, and the accuracy of the limit travel identification is improved. When it is detected that the acceleration change rate is greater than the acceleration change rate threshold value or the limit difference value is greater than the limit difference threshold value, it can be determined that the suspension of the vehicle enters the limit travel, so as to timely and accurately adjust the damper damping and improve the comfort of the vehicle.

[0008] In some optional embodiments, the acceleration change rate threshold value and the limit difference threshold value are obtained according to the driving mode, the vehicle speed and the roughness and the road surface type of the driving road surface of the vehicle, including: querying a preset threshold table based on the driving mode, the vehicle speed and the roughness to obtain an acceleration change rate threshold value and a limit difference threshold value; correcting the acceleration change rate threshold value and the limit difference threshold value according to the road surface type to obtain the acceleration change rate threshold value and the limit difference threshold value.

[0009] The present application first queries the acceleration change rate threshold value and the limit difference threshold value that match the driving mode, the vehicle speed and the roughness by using the preset threshold table. Then, the acceleration change rate threshold value and the limit difference threshold value are corrected in combination with the road surface type of the driving road surface of the vehicle, so that the obtained acceleration change rate threshold value and limit difference threshold value are more consistent with the actual working condition of the vehicle and the driving road surface, thereby improving the accuracy of the limit travel identification.

[0010] In some optional embodiments, the acceleration change rate threshold value and the limit difference threshold value are obtained according to the road surface type, including: judging whether the road surface type is a convex road surface or a concave road surface; if the road surface type is the convex road surface or the concave road surface, taking the acceleration change rate threshold value as the acceleration change rate threshold value and taking the limit difference threshold value as the limit difference threshold value; If the road surface type is not a convex road surface or a concave road surface, the absolute values of the acceleration change rate threshold and the limit difference threshold are increased to obtain the acceleration change rate threshold and the limit difference threshold.

[0011] The application obtains the acceleration change rate threshold and the limit difference threshold by looking up the table if the road surface type is a convex road surface or a concave road surface, and modifies the acceleration change rate threshold and the limit difference threshold if the road surface type is neither a convex road surface nor a concave road surface, and increases the absolute values of the acceleration change rate threshold and the limit difference threshold, so as to avoid false detection of the vehicle suspension entering the limit stroke in the case of slight wheel vibration and improve the accuracy of limit stroke identification.

[0012] In some optional embodiments, the road surface type of the vehicle driving road surface is determined based on the motion direction and the acceleration change rate, and the method comprises: obtaining the acceleration change trend according to the acceleration change rate; when it is detected that the motion direction is upward motion of the shock absorber relative to the vehicle body and the acceleration change trend is increasing in the motion direction, determining that the road surface type of the vehicle driving road surface is a convex road surface; when it is detected that the motion direction is downward motion of the shock absorber relative to the vehicle body and the acceleration change trend is increasing in the motion direction, determining that the road surface type of the vehicle driving road surface is a concave road surface.

[0013] The application determines the road surface type of the vehicle driving road surface by combining the motion direction of the shock absorber relative to the vehicle body and the change trend of the acceleration change rate in the motion direction, improves the reliability of road surface type identification, avoids misjudgment on a smooth road surface, and selects the appropriate acceleration change rate threshold and limit difference threshold in combination with the road surface type.

[0014] In some optional embodiments, after obtaining the limit difference threshold, the method further comprises: when it is detected that the acceleration change rate is less than the first acceleration change rate threshold, or the roughness is greater than the first roughness threshold, or the driving mode is a sports mode, increasing the absolute value of the limit difference threshold; when it is detected that the acceleration change rate is greater than the second acceleration change rate threshold, or the roughness is less than the second roughness threshold, or the driving mode is a comfort mode, decreasing the absolute value of the limit difference threshold; wherein the second acceleration change rate threshold is greater than the first acceleration change rate threshold, and the second roughness threshold is less than the first roughness threshold.

[0015] The application combines the acceleration rate of the sprung acceleration signal, the roughness of the road surface and the driving mode of the vehicle to make a secondary correction to the limit difference threshold. When the acceleration rate is small, the road surface is rough or the vehicle is in the sports mode, the absolute value of the limit difference threshold is increased to adjust the identification timing of the limit travel, so as to balance the vehicle comfort, vehicle safety and suspension performance control. When the acceleration rate is large, the road surface is flat or the vehicle is in the comfort mode, the absolute value of the limit difference threshold is reduced to improve the sensitivity of the limit travel identification, so as to timely adjust the damper damping force and ensure the vehicle comfort.

[0016] In some optional embodiments, the determination of the movement direction of the damper on the suspension relative to the vehicle body based on the sprung acceleration signal and the unsprung acceleration signal comprises: According to the sprung acceleration signal and the unsprung acceleration signal, the sprung speed and the unsprung speed are obtained. The relative speed of the unsprung speed relative to the sprung speed is calculated, and the movement direction of the damper relative to the vehicle body is obtained according to the positive and negative types of the relative speed.

[0017] The application calculates the relative speed of the unsprung speed relative to the sprung speed through the sprung acceleration signal and the unsprung acceleration signal, analyzes the relative movement of the damper, identifies the movement direction of the damper relative to the vehicle body, and provides an important direction reference for subsequent road type identification. Compared with the single sensor identification scheme, the accuracy of the movement direction identification can be improved.

[0018] In some optional embodiments, after the determination that the vehicle suspension enters the limit travel, the method further comprises: Determining the target control current of the damper; Adjusting the damping force of the damper based on the target control current.

[0019] After the identification that the suspension enters the limit travel, the target control current of the damper is determined, the electromagnetic valve of the damper is adjusted by using the target control current, the damping force of the damper reaches the target damping force under the limit travel, and thus the vehicle comfort is improved.

[0020] In a second aspect, the application provides a limit travel identification device for a vehicle suspension, which comprises: An acquisition module is configured to acquire the driving mode, the vehicle speed, the sprung acceleration signal and the unsprung acceleration signal of the vehicle suspension; A first processing module is configured to determine the roughness of the driving road surface and the movement direction of the damper on the suspension relative to the vehicle body based on the sprung acceleration signal and the unsprung acceleration signal. The second processing module is configured to determine a limit difference value and an acceleration change rate of the unsprung acceleration signal, and determine a road surface type of a driving road surface of the vehicle based on a motion direction and the acceleration change rate. The third processing module is configured to obtain an acceleration change rate threshold value and a limit difference threshold value according to a driving mode of the vehicle, a vehicle speed, and roughness and the road surface type of the driving road surface of the vehicle, and correct the limit difference threshold value based on the acceleration change rate, the roughness, and the driving mode to obtain a second limit difference threshold value. The fourth processing module is configured to determine that the suspension of the vehicle enters the limit travel when it is detected that the acceleration change rate is greater than the acceleration change rate threshold value, or the limit difference value is greater than the second limit difference threshold value.

[0021] In a third aspect, the present application provides an electronic device, comprising a memory and a processor, the memory and the processor are communicatively connected with each other, the memory stores computer instructions, and the processor executes the computer instructions to perform the limit travel identification method of the vehicle suspension in the first aspect or any of the corresponding embodiments thereof.

[0022] In a fourth aspect, the present application provides a computer readable storage medium, which stores computer instructions, and the computer instructions are used to make a computer execute the limit travel identification method of the vehicle suspension in the first aspect or any of the corresponding embodiments thereof.

[0023] In a fifth aspect, the present application provides a computer program product, which comprises computer instructions, and the computer instructions are used to make a computer execute the limit travel identification method of the vehicle suspension in the first aspect or any of the corresponding embodiments thereof.

[0024] The present application has the following beneficial effects: The present application determines the roughness and the road surface type of the driving road surface of the vehicle through the sprung acceleration signal and the unsprung acceleration signal of the suspension. Then, according to the driving mode of the vehicle, the vehicle speed, and the roughness and the road surface type of the road surface, the acceleration change rate threshold value and the limit difference threshold value that are more suitable for the working condition of the vehicle are selected. Thus, when the limit travel is identified according to the acceleration change rate threshold value and the limit difference threshold value, the actual state of the vehicle and the actual working condition of the vehicle are more suitable, and the accuracy of the limit travel identification is improved. When it is detected that the acceleration change rate is greater than the acceleration change rate threshold value or the limit difference value is greater than the limit difference threshold value, it can be determined that the suspension of the vehicle enters the limit travel, so as to timely and accurately adjust the damper damping and improve the comfort of the vehicle. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the specific embodiments of the present application or the prior art, the accompanying drawings needed to be used in the description of the specific embodiments or the prior art will be briefly introduced. Obviously, the accompanying drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0026] Figure 1 is a first system block diagram of a vehicle suspension system according to an embodiment of the present application; Figure 2 is a second system block diagram of a vehicle suspension system according to an embodiment of the present application; Figure 3 is a first flowchart of a limit travel identification method of a vehicle suspension according to an embodiment of the present application; Figure 4 is a second flowchart of a limit travel identification method of a vehicle suspension according to an embodiment of the present application; Figure 5 is a structural block diagram of a limit travel identification device of a vehicle suspension according to an embodiment of the present application; Figure 6 is a hardware structure diagram of an electronic device according to an embodiment of the present application. DETAILED DESCRIPTION

[0027] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without any creative effort belong to the scope of protection of the present application.

[0028] It can be understood that, before using the technical solutions disclosed in the embodiments of the present application, the type, use range, use scenario and the like of the personal information involved in the present application should be informed to the user and the authorization of the user should be obtained through appropriate means according to relevant laws and regulations.

[0029] The terms "first", "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more than two, unless otherwise specifically limited.

[0030] The related technology focuses on the control of the shock absorber damping force after the suspension enters the limit stroke, and the limit stroke is identified by judging whether the sensor signal reaches the preset value, but the preset value cannot match all real vehicle conditions, resulting in inaccurate identification of the limit stroke, and the phenomenon of missing or false detection is prone to occur, so that the vehicle cannot adjust or incorrectly adjust the shock absorber damping in time, affecting the comfort of the vehicle and causing user discomfort.

[0031] The embodiment of the present application provides a limit stroke identification method of a vehicle suspension, which determines the roughness and type of the driving road surface of the vehicle by using the sprung acceleration signal and the unsprung acceleration signal of the suspension, so as to select the acceleration change rate threshold and the limit difference threshold suitable for the current vehicle condition in combination with the driving mode, speed, roughness and type of the driving road surface of the vehicle, so as to determine that the vehicle suspension enters the limit stroke when the acceleration change rate of the unsprung acceleration signal is greater than the acceleration change rate threshold or the limit difference value of the unsprung acceleration signal is greater than the limit difference threshold. By selecting the acceleration change rate threshold and the limit difference threshold suitable for the driving mode, speed, roughness and type of the driving road surface of the vehicle, the accuracy of the limit stroke identification of the suspension is improved, so as to adjust the shock absorber damping in time and correctly, and improve the comfort of the vehicle.

[0032] As an optional application scenario of the embodiment of the present application, a vehicle suspension system is provided, as shown in Figure 1 The vehicle suspension system includes an electronic device for master control, a plurality of shock absorbers located on the vehicle suspension, and an acceleration sensor, wherein each shock absorber is located on the left front suspension, the right front suspension, the left rear suspension and the right rear suspension of the vehicle respectively. The electronic device is connected to the vehicle CAN through a twisted pair, communicates with other controllers of the vehicle through CANFD, and is connected to the vehicle power supply, the acceleration sensor and the electromagnetic valve of each shock absorber through a wire harness. It should be noted that the electronic device for master control can be a control device such as a vehicle motion control (VMC) and a vehicle control unit (VCU), as long as it can realize the control function, and the present application is not limited thereto.

[0033] Specifically, the acceleration sensor includes a sprung acceleration sensor and an unsprung acceleration sensor, for example, an inertial measurement unit (IMU), which is used to collect the sprung acceleration signal of the suspension; and the unsprung acceleration sensor is used to collect the unsprung acceleration signal of the suspension.

[0034] In some embodiments, referring again to Figure 1The electronic device for master control is integrated with an ECDC software and a driving circuit, wherein the ECDC software comprises a signal preprocessing module 101, a road roughness identification module 102, a mode management module 103, a limit travel identification module 104 and a damping force execution module 105, and the driving circuit comprises a driving chip and a switching device.

[0035] As shown in Figure 2 The signal preprocessing module 101 comprises an on-spring sensor signal preprocessing module, an off-spring sensor signal preprocessing module and a sensor signal configuration module, wherein the on-spring sensor signal preprocessing module is used for filtering and other preprocessing of the on-spring acceleration signal, and the off-spring sensor signal preprocessing module is used for filtering, noise reduction and other preprocessing of the off-spring acceleration signal. The sensor signal configuration module unifies the interface format between the sensor and the corresponding signal preprocessing module according to the vehicle sensor configuration scheme, and ensures the compatibility between the modules. The signal preprocessing module 101 preprocesses the communication signals of other vehicle controllers and converts them into internal interface signals of the ECDC software module. Finally, the signal preprocessing module 101 outputs the on-spring acceleration signal, the off-spring acceleration signal, the vehicle speed and the whole vehicle communication signal.

[0036] The road roughness identification module 102 identifies the roughness of the current vehicle driving road according to the sensor signals output by the signal preprocessing module 101 and outputs the same.

[0037] The mode management module 103 outputs the driving mode of the vehicle according to the whole vehicle communication signal.

[0038] The limit travel identification module 104 identifies whether the suspension enters the limit travel under different driving road conditions and vehicle driving modes according to the output signals of the signal preprocessing module 101, the road roughness identification module 102 and the mode management module 103. If the limit travel identification module 104 identifies that the suspension enters the limit travel, the damping force execution module 105 is used for damping force adjustment.

[0039] The damping force execution module 105 obtains the vehicle demand damping force finally arbitrated by the ECDC software after identifying that the suspension enters the limit travel, determines the target control current of the corresponding shock absorber electromagnetic valve according to the vehicle demand damping force, and converts the target control current into a pulse width modulation (PWM) control signal. The generated PWM control signal is input to the driving chip in the driving circuit, and the driving chip drives the switching device (such as a MOS switch tube) according to the PWM control signal, so as to adjust the control current of the corresponding shock absorber electromagnetic valve to the target control current, thereby realizing the damping force adjustment of the shock absorber when the suspension enters the limit travel.

[0040] In some embodiments, referring again to Figure 2 , the limit travel identification module 104 includes an acceleration processing module, a road surface type identification module, a preset threshold table module, and a limit travel determination module.

[0041] The acceleration processing module processes the sprung acceleration signal and the unsprung acceleration signal to identify the motion direction of the shock absorber relative to the vehicle body, the limit values (including the maximum value and the minimum value) of the sprung acceleration signal and the unsprung acceleration signal, and the acceleration change rate, etc.

[0042] The road surface type identification module determines the road surface type of the vehicle driving road according to the output of the acceleration processing module. The preset threshold table module determines the acceleration change rate threshold and the limit difference threshold based on the output of the acceleration processing module and the road surface type identification module, in combination with the vehicle speed, the driving mode, the road surface type, and the roughness. The limit travel determination module determines whether the vehicle suspension enters the limit travel according to the output of the acceleration processing module, the road surface type identification module, and the preset threshold table module.

[0043] The specific working process of the ECDC software will be described in detail in the following method embodiment, and will not be described here.

[0044] According to the embodiments of the present application, a limit travel identification method for a vehicle suspension is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although the logical order is shown in the flowchart, in some cases, the steps shown or described herein can be executed in a different order.

[0045] In this embodiment, a limit travel identification method for a vehicle suspension is provided, which can be used in a vehicle suspension system as shown in Figure 1 , such as an electronic device for master control, such as a chassis controller, a vehicle controller, etc. Figure 3 , the flowchart of the limit travel identification method for a vehicle suspension according to the embodiments of the present application, as shown in Figure 3 , the flowchart includes the following steps: Step S301, obtaining the driving mode of the vehicle, the vehicle speed, and the sprung acceleration signal and the unsprung acceleration signal of the suspension.

[0046] Specifically, referring again to Figure 1The sprung acceleration sensor and the unsprung acceleration sensor respectively transmit the collected sprung acceleration signal and unsprung acceleration signal to the electronic device, and the electronic device also communicates with other controllers to obtain a whole vehicle communication signal. The whole vehicle communication signal includes but is not limited to various driver operation signals (such as brake pedal stroke, brake master cylinder pressure, accelerator pedal opening, steering wheel angle and steering wheel angle speed signals), vehicle driving signals (such as vehicle speed, whole vehicle driving torque, etc.), vehicle attitude signals (such as vehicle longitudinal acceleration, vehicle lateral acceleration, etc.), and suspension movement signals (such as sprung acceleration signal, unsprung acceleration signal, sprung speed and unsprung speed, etc.).

[0047] Specifically, the driving mode of the vehicle is determined based on the whole vehicle communication signal, wherein the driving mode of the vehicle includes a sport mode and a comfort mode.

[0048] In some embodiments, the driving state of the vehicle is determined according to the whole vehicle communication signal, and if the driving state meets a preset driving state, it is determined that the vehicle is in the sport mode; otherwise, it is determined that the vehicle is in the comfort mode. The preset driving state includes an emergency braking state, an emergency acceleration state, and a steady-state steering state.

[0049] For example, when it is detected that the change rate of the brake pedal stroke is greater than a brake pedal stroke change rate threshold (i.e., the brake pedal is stepped down rapidly), the brake master cylinder pressure is greater than a brake master cylinder pressure threshold (i.e., the brake master cylinder generates high pressure), the vehicle longitudinal acceleration is less than a first longitudinal acceleration threshold (i.e., the vehicle is high deceleration), and the whole vehicle driving torque is less than a first driving torque threshold, it is determined that the vehicle is in the emergency braking state.

[0050] For example, when it is detected that the change rate of the accelerator pedal opening is greater than an accelerator pedal opening change rate threshold (i.e., the accelerator pedal is stepped down rapidly), the accelerator pedal opening is greater than an accelerator pedal opening threshold, the whole vehicle driving torque is greater than a second driving torque threshold, and the vehicle longitudinal acceleration is greater than a second longitudinal acceleration threshold (i.e., the vehicle is high acceleration), it is determined that the vehicle is in the emergency acceleration state. The second driving torque threshold is greater than the first driving torque threshold, and the second longitudinal acceleration threshold is greater than the first longitudinal acceleration threshold.

[0051] For example, when it is detected that the steering wheel angle is greater than an angle threshold, the steering wheel angle speed is less than an angle speed threshold, the vehicle lateral acceleration is greater than a lateral acceleration threshold, the change rate of the vehicle lateral acceleration is less than a lateral acceleration change rate threshold, and the vehicle speed is greater than a vehicle speed threshold, it is determined that the vehicle is in the steady-state steering state.

[0052] In step S302, the roughness of the vehicle driving road surface and the movement direction of the shock absorber on the suspension relative to the vehicle body are determined based on the sprung acceleration signal and the unsprung acceleration signal.

[0053] Specifically, the vibration characteristics of the unsprung acceleration signal reflect the impact strength and frequency of the road surface input to the vehicle tire, and the vibration characteristics of the sprung acceleration signal reflect the vibration strength transmitted to the vehicle body, so the roughness of the vehicle driving road can be determined through the sprung acceleration signal and the unsprung acceleration signal.

[0054] In this embodiment, the roughness of the vehicle driving road can be divided into different levels, and the higher the roughness level, the rougher the vehicle driving road. For example, roughness level 1 can represent a flat road, roughness level 2 can represent a general road, and roughness level 3 can represent a rough road. The specific classification can be set according to the actual scene requirements, and the present embodiment is not limited thereto.

[0055] In some embodiments, the original unsprung acceleration signal is filtered to remove high-frequency interference caused by the sensor to retain the main frequency band of the road excitation input. Then, the root mean square (RMS) of the unsprung acceleration signal is calculated, and a plurality of RMS threshold intervals are set in advance, each RMS threshold interval corresponding to a different roughness level.

[0056] For example, when the root mean square of the unsprung acceleration signal is detected to be less than a first RMS threshold, it is determined that the roughness of the vehicle driving road corresponds to a flat road; when the root mean square of the unsprung acceleration signal is not less than the first RMS threshold and less than a second RMS threshold, it is determined that the roughness of the vehicle driving road corresponds to a general road; when the root mean square of the unsprung acceleration signal is not less than the second RMS threshold, it is determined that the roughness of the vehicle driving road corresponds to a rough road, and the corresponding roughness level is output. The first RMS threshold is less than the second RMS threshold, and the values of the first RMS threshold and the second RMS threshold can be determined by measuring the root mean square of the unsprung acceleration signal on the corresponding roughness road in advance.

[0057] In this embodiment, the sprung speed and the unsprung speed are obtained through the sprung acceleration signal and the unsprung acceleration signal, and then the movement direction of the shock absorber on the suspension relative to the vehicle body is obtained according to the sprung speed and the unsprung speed. If the movement direction is that the shock absorber moves upward relative to the vehicle body, it indicates that the shock absorber is in compression stroke; if the movement direction is that the shock absorber moves downward relative to the vehicle body, it indicates that the shock absorber is in extension stroke.

[0058] Step S303, determining the limit difference value and the acceleration change rate of the unsprung acceleration signal, and determining the road type of the vehicle driving road based on the movement direction and the acceleration change rate.

[0059] Specifically, the maximum value and the minimum value of the unsprung acceleration signal are determined, and the limit difference value of the unsprung acceleration signal is obtained by calculating the difference between the maximum value and the minimum value.

[0060] In some embodiments, the maximum value of the unsprung acceleration signal can be found when the shock absorber is in the compression stroke, i.e., the shock absorber moves upward relative to the vehicle body; and the minimum value of the unsprung acceleration signal can be found when the shock absorber is in the stretching stroke, i.e., the shock absorber moves downward relative to the vehicle body.

[0061] Specifically, the road surface type of the vehicle driving road surface can be divided into convex road surface and concave road surface. When the vehicle drives on the convex road surface and the concave road surface, the movement direction of the shock absorber relative to the vehicle body and the acceleration change rate of the unsprung acceleration will produce different changes, so the road surface type of the vehicle driving road surface can be comprehensively identified in combination with the movement direction of the shock absorber and the acceleration change rate of the unsprung acceleration, and misjudgment can be avoided.

[0062] In step S304, the acceleration change rate threshold value and the limit difference threshold value are obtained according to the driving mode of the vehicle, the vehicle speed, and the roughness and the road surface type of the vehicle driving road surface.

[0063] Since the related art determines whether the suspension enters the limit stroke by judging whether the sensor signal reaches the preset value, but the preset value cannot completely match the current real vehicle working condition, the identification of the limit stroke is not accurate, and the limit stroke identification may be missed or misdetected into the limit stroke.

[0064] Therefore, the embodiment combines the current driving mode of the vehicle, the vehicle speed, and the roughness level and the road surface type of the driving road surface to select the matching acceleration change rate threshold value and the limit difference threshold value. Thus, during the vehicle driving process, the appropriate acceleration change rate threshold value and the limit difference threshold value can be selected according to the actual state of the vehicle and the real vehicle working condition, so as to be more matched with the actual state of the vehicle and the real vehicle working condition when the limit stroke is identified according to the acceleration change rate threshold value and the limit difference threshold value, and the accuracy of the limit stroke identification is improved, so as to timely and accurately adjust the shock absorber damping and improve the vehicle comfort.

[0065] In step S305, when it is detected that the acceleration change rate is greater than the acceleration change rate threshold value, or the limit difference value is greater than the limit difference threshold value, it is determined that the vehicle suspension enters the limit stroke.

[0066] Specifically, when the vehicle suspension approaches the limit stroke, the motion of the unsprung mass (i.e., the wheel) will be greatly resisted, generating a huge inertial impact, causing a sudden dramatic change in the unsprung acceleration signal. The unsprung acceleration will also experience a change from a positive maximum value to a negative minimum value (or from a negative minimum value to a positive maximum value) in the stroke of the shock absorber from the compression limit to the stretching limit (or from the stretching limit to the compression limit). The embodiment determines that the vehicle suspension enters the limit stroke when it is detected that the acceleration change rate of the unsprung acceleration signal is greater than the acceleration change rate threshold value, or the limit difference value of the unsprung acceleration signal is greater than the limit difference threshold value.

[0067] The vehicle suspension limit travel recognition method provided in the embodiment determines the roughness and type of the road surface on which the vehicle travels through the sprung acceleration signal and the unsprung acceleration signal of the suspension. Then, according to the driving mode, the vehicle speed, and the roughness and type of the road surface, the acceleration change rate threshold and the limit difference threshold that are more suitable for the working condition of the vehicle are selected. Thus, when the limit travel is recognized according to the acceleration change rate threshold and the limit difference threshold, the actual state of the vehicle and the actual working condition of the vehicle are more suitable, and the accuracy of the limit travel recognition is improved. When the acceleration change rate is greater than the acceleration change rate threshold or the limit difference value is greater than the limit difference threshold, it is determined that the suspension of the vehicle enters the limit travel, so as to timely and accurately adjust the damper damping and improve the comfort of the vehicle.

[0068] In the embodiment, a vehicle suspension limit travel recognition method is provided, which can be used in the electronic device for master control, such as the chassis controller, the vehicle controller, etc., in the vehicle suspension system as shown in Figure 1 Figure 4 The flowchart of the vehicle suspension limit travel recognition method according to the embodiment of the application is shown in Figure 4 The flowchart includes the following steps: In step S401, the driving mode, the vehicle speed, and the sprung acceleration signal and the unsprung acceleration signal of the suspension of the vehicle are obtained. For details, refer to the detailed description of step S301 in the embodiment shown in Figure 3

[0069] In step S402, the roughness of the road surface on which the vehicle travels and the movement direction of the damper on the suspension relative to the vehicle body are determined based on the sprung acceleration signal and the unsprung acceleration signal.

[0070] Specifically, the sprung speed and the unsprung speed are obtained according to the sprung acceleration signal and the unsprung acceleration signal. Then, the relative speed of the unsprung speed relative to the sprung speed is calculated, and the movement direction of the damper relative to the vehicle body is obtained according to the positive and negative type of the relative speed.

[0071] In some embodiments, the sprung speed and the unsprung speed can be obtained by integrating the sprung acceleration signal and the unsprung acceleration signal. The difference between the unsprung speed and the sprung speed is calculated to obtain the relative speed of the unsprung speed relative to the sprung speed. If the positive and negative type of the relative speed is positive, it indicates that the damper is in the compression travel, and the damper moves upward relative to the vehicle body; if the positive and negative type of the relative speed is negative, it indicates that the damper is in the stretching travel, and the damper moves downward relative to the vehicle body.

[0072] ​​The embodiment calculates the relative velocity of the unsprung velocity relative to the sprung velocity through the sprung acceleration signal and the unsprung acceleration signal, analyzes the relative motion of the shock absorber, identifies the motion direction of the shock absorber relative to the vehicle body, and provides an important direction reference for subsequent road type identification. Compared with the single sensor identification scheme, the accuracy of the motion direction identification can be improved.

[0073] In step S403, the limit difference value and the acceleration change rate of the unsprung acceleration signal are determined, and the road surface type of the vehicle driving road is determined based on the motion direction and the acceleration change rate.

[0074] Specifically, the above step S403 includes: In step S4031, the limit difference value and the acceleration change rate of the unsprung acceleration signal are determined, and the acceleration change trend is obtained according to the acceleration change rate.

[0075] Specifically, the limit difference value between the maximum value and the minimum value of the unsprung acceleration signal is calculated, the acceleration change rate of the unsprung acceleration signal is obtained by differentiating the unsprung acceleration signal, and the acceleration change trend is obtained by analyzing the change of the acceleration change rate at the current time relative to the acceleration change rate at the previous time.

[0076] In step S4032, when it is detected that the motion direction is upward motion of the shock absorber relative to the vehicle body and the acceleration change trend is increasing in the motion direction, it is determined that the road surface type of the vehicle driving road is a convex road surface.

[0077] Specifically, in the process of upward motion of the shock absorber relative to the vehicle body, the shock absorber is in compression stroke, and when it is identified that the acceleration change trend is increasing in the above motion direction, it is indicated that the wheel is subjected to upward force, and it is most likely to drive on the convex road surface, so the road surface type is determined as a convex road surface.

[0078] In step S4033, when it is detected that the motion direction is downward motion of the shock absorber relative to the vehicle body and the acceleration change trend is increasing in the motion direction, it is determined that the road surface type of the vehicle driving road is a pit road surface.

[0079] Specifically, in the process of downward motion of the shock absorber relative to the vehicle body, the shock absorber is in tension stroke, and when it is identified that the acceleration change trend is increasing in the above motion direction, it is indicated that the wheel is mainly subjected to the action of gravity to accelerate downward, and the wheel is most likely to fall into the pit without support, so the road surface type is determined as a pit road surface.

[0080] The embodiment combines the movement direction of the shock absorber relative to the vehicle body and the change trend of the acceleration change rate in the movement direction to comprehensively determine the road surface type of the vehicle driving road surface, improve the reliability of road surface type identification, avoid misjudgment on a smooth road surface, and select an appropriate acceleration change rate threshold and limit difference threshold according to the road surface type.

[0081] In step S404, the acceleration change rate threshold and the limit difference threshold are obtained according to the driving mode of the vehicle, the vehicle speed, and the roughness and the road surface type of the vehicle driving road surface.

[0082] Specifically, the step S404 includes: In step S4041, the acceleration change rate threshold and the limit difference threshold are obtained by querying a preset threshold table based on the driving mode, the vehicle speed, and the roughness.

[0083] Specifically, the corresponding acceleration change rate preset threshold table and the limit difference preset threshold table are respectively set according to different driving modes. The acceleration change rate threshold and the limit difference threshold are obtained by querying the acceleration change rate preset threshold table and the limit difference preset threshold table based on the driving mode, the vehicle speed, and the roughness.

[0084] For example, the corresponding acceleration change rate preset threshold table of the driving mode as the sports mode is shown in Table One as follows: Table One: Acceleration change rate preset threshold table of sports mode

[0085] It should be noted that in the above vehicle speed intervals, the vehicle speeds corresponding to the first to fifth vehicle speed intervals gradually increase. When the roughness level is the same, the higher the vehicle speed, the greater the corresponding acceleration change rate threshold, that is, a5>a4>a3>a2>a1, b5>b4>b3>b2>b1, c5>c4>c3>c2>c1. When the vehicle speed interval is the same, the higher the roughness level of the road surface, the greater the corresponding acceleration change rate threshold, that is, c1>b1>a1, c2>b2>a2, c3>b3>a3, c4>b4>a4, c5>b5>a5.

[0086] For example, the corresponding limit difference preset threshold table of the driving mode as the comfort mode is shown in Table Two as follows: Table Two: Limit difference preset threshold table of sports mode

[0087] It should be noted that in the above vehicle speed intervals, the vehicle speeds corresponding to the first to fifth vehicle speed intervals gradually increase, and when the roughness levels are the same, the higher the vehicle speed, the greater the corresponding limit difference threshold value, that is, j5>j4>j3>j2>j1, k5>k4>k3>k2>k1, i5>i4>i3>i2>i1; when the vehicle speed intervals are the same, the higher the roughness level of the road surface, the greater the corresponding limit difference threshold value, that is, i1>k1>j1, i2>k2>j2, i3>k3>j3, i4>k4>j4, i5>k5>j5.

[0088] In step S4042, the acceleration change rate threshold value and the limit difference threshold value are corrected according to the road surface type.

[0089] In some optional embodiments, the step S4042 includes: In step a1, it is judged whether the road surface type is a convex road surface or a concave road surface.

[0090] In step a2, if the road surface type is a convex road surface or a concave road surface, the acceleration change rate threshold value is taken as the acceleration change rate threshold value, and the limit difference threshold value is taken as the limit difference threshold value.

[0091] In step a3, if the road surface type is not a convex road surface or a concave road surface, the absolute values of the acceleration change rate threshold value and the limit difference threshold value are increased to obtain the acceleration change rate threshold value and the limit difference threshold value.

[0092] Specifically, if the road surface type is neither a convex road surface nor a concave road surface, the acceleration change rate threshold value and the limit difference threshold value are multiplied by a preset multiple (for example, 120%) respectively, so as to increase the absolute values of the acceleration change rate threshold value and the limit difference threshold value, and obtain the acceleration change rate threshold value and the limit difference threshold value.

[0093] In this embodiment, when the road surface type is a convex road surface or a concave road surface, the acceleration change rate threshold value and the limit difference threshold value obtained by the table lookup are taken as the acceleration change rate threshold value and the limit difference threshold value respectively which are adapted to the actual working condition of the vehicle; if the road surface type is neither a convex road surface nor a concave road surface, the acceleration change rate threshold value and the limit difference threshold value are corrected, and the absolute values of the acceleration change rate threshold value and the limit difference threshold value are increased, so as to avoid false detection of the vehicle suspension entering the limit stroke in the case of slight wheel vibration, and improve the accuracy of limit stroke identification.

[0094] In the above embodiments, the application first queries the acceleration change rate threshold value and the limit difference threshold value matching the driving mode, the vehicle speed and the roughness by using the preset threshold table. Then, the acceleration change rate threshold value and the limit difference threshold value are corrected in combination with the road type on which the vehicle is currently driving, so that the obtained acceleration change rate threshold value and the limit difference threshold value are more suitable for the actual working condition and the driving road of the vehicle, thereby improving the accuracy of the limit travel recognition.

[0095] In some optional embodiments, after obtaining the limit difference threshold value, the limit difference threshold value is secondarily corrected according to the acceleration change rate, the roughness and the driving mode.

[0096] Specifically, when the acceleration change rate is less than the first acceleration change rate threshold value, or the roughness is greater than the first roughness threshold value, or the driving mode is the sports mode, the absolute value of the limit difference threshold value is increased. The increase of the absolute value of the limit difference threshold value means that the limit difference threshold value is adaptively corrected in the direction of the increase of the absolute value, and the increase range of the absolute value can be a preset increase range. The preset increase range, the first acceleration change rate threshold value and the first roughness threshold value can be calibrated in advance by real vehicle test data.

[0097] In the present embodiment, when the acceleration change rate is less than the first acceleration change rate threshold value, the suspension system is experiencing a slowly changing impact, and the limit difference threshold value is secondarily corrected by increasing the absolute value of the limit difference threshold value, so as to avoid the early recognition of the limit travel and the early adjustment of the damper damping.

[0098] In the present embodiment, when the roughness of the road is greater than the first roughness threshold value, random road excitation inputs will appear on the high roughness road, and the suspension system will be subjected to random vibration impact. By increasing the absolute value of the limit difference threshold value, the limit difference threshold value is corrected to ensure that the limit travel control is triggered only under a significant abnormal impact, so as to avoid the suspension system being in the damping force adjustment state all the time under the continuous high-intensity vibration of the relatively rough road, and prevent the performance degradation of the suspension system.

[0099] In the present embodiment, when the vehicle is in the sports mode (the emergency braking state, the emergency acceleration state and the steady-state steering state), the system will preferentially ensure the control accuracy of the vehicle in the sports mode. At this time, the main goal is to ensure that the vehicle can accurately realize the emergency braking, the emergency acceleration or the steady-state steering, and the vehicle comfort is the secondary goal. Therefore, by increasing the absolute value of the limit difference threshold value, the recognition time and the damping force adjustment time of the limit travel are delayed, so as to ensure the safety of the vehicle at the expense of a certain comfort.

[0100] Specifically, when it is detected that the acceleration change rate is greater than a second acceleration change rate threshold, or, the roughness is less than a second roughness threshold, or, the driving mode is a comfort mode, the absolute value of the limit difference threshold is reduced; wherein the second acceleration change rate threshold is greater than the first acceleration change rate threshold, and the second roughness threshold is less than the first roughness threshold. It should be noted that reducing the absolute value of the limit difference threshold means that the limit difference threshold is adaptively corrected in the direction of reducing the absolute value, and the reduction amplitude of the absolute value can be a preset reduction amplitude. The preset reduction amplitude, the second acceleration change rate threshold and the second roughness threshold can be calibrated in advance through real vehicle test data.

[0101] In the embodiment, when the acceleration change rate of the suspension unsprung acceleration is greater than the second acceleration change rate threshold, it indicates that the suspension is experiencing a high-intensity transient impact. By reducing the absolute value of the limit difference threshold, the sensitivity of the limit travel recognition is improved, so as to adjust the shock absorber damping force at the initial stage of the impact, and improve the comfort of the vehicle under the transient impact.

[0102] In the embodiment, when the vehicle is running on a low-roughness road surface, by reducing the absolute value of the limit difference threshold, the sensitivity of the suspension system to the recognition of small vibration impact is improved, so as to adjust the damping force in time after the limit travel is recognized, which is beneficial to further improve the vehicle comfort in the case of good road conditions.

[0103] In the embodiment, when the vehicle is in the comfort mode, at this time the vehicle mainly targets the comfort, by reducing the absolute value of the limit difference threshold, the limit travel can also be recognized under small impact, so as to adjust the shock absorber damping force, and further improve the vehicle comfort.

[0104] The embodiment combines the acceleration change rate of the unsprung acceleration signal, the roughness of the road surface and the driving mode of the vehicle to make a secondary correction to the limit difference threshold. When the acceleration change rate is small, the road surface is rough or the vehicle is in the sports mode, the absolute value of the limit difference threshold is increased to adjust the recognition timing of the limit travel, and the vehicle comfort adjustment, vehicle safety and suspension performance control are balanced. When the acceleration change rate is large, the road surface is smooth or the vehicle is in the comfort mode, the absolute value of the limit difference threshold is reduced to improve the sensitivity of the limit travel recognition, so as to adjust the shock absorber damping force in time and ensure the vehicle comfort.

[0105] In step S405, when it is detected that the acceleration change rate is greater than the acceleration change rate threshold, or, the limit difference value is greater than the limit difference threshold, it is determined that the vehicle suspension enters the limit travel.

[0106] In some optional embodiments, after the limit travel is recognized, a target control current of the shock absorber is determined, and the damping force of the shock absorber is adjusted based on the target control current.

[0107] In some embodiments, the direction of motion of the shock absorber relative to the vehicle body can be used to determine whether the shock absorber is at its compression limit or extension limit. If it is at its compression limit (or extension limit), the target control current of the shock absorber at its extension limit is determined by combining the pre-stored maximum compression damping current curve (or maximum extension damping current curve). The maximum compression damping current curve and the maximum extension damping current curve can be obtained by processing real vehicle test data. In these curves, the current and damping exhibit a specific mapping relationship.

[0108] In this embodiment, after the suspension enters its limit travel, the target control current of the shock absorber is determined. The shock absorber solenoid valve is adjusted using the target control current so that the damping force of the shock absorber reaches the target damping force at the limit travel, thereby improving vehicle comfort.

[0109] The vehicle suspension limit travel identification method provided in this embodiment selects acceleration change rate threshold and limit difference threshold that are more suitable for the vehicle's operating conditions based on the vehicle's driving mode, speed, road surface roughness, and type. This enables real-time adjustment of the acceleration change rate threshold and limit difference threshold, adapting to various operating conditions and improving system robustness, thus moving beyond the limitation of solving only a single operating condition problem. This invention improves the accuracy and flexibility of limit travel identification, thereby applying the target control current reasonably under special operating conditions as much as possible, avoiding abnormal noise from the shock absorbers and affecting the overall vehicle comfort.

[0110] This embodiment also provides a vehicle suspension limit travel recognition device, which is used to implement the above embodiments and preferred embodiments; details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that implements a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0111] This embodiment provides a vehicle suspension limit travel recognition device, such as... Figure 5 As shown, it includes: The acquisition module 501 is used to acquire the vehicle's driving mode, vehicle speed, and the sprung acceleration signal and unsprung acceleration signal of the suspension. The first processing module 502 is used to determine the roughness of the road surface on which the vehicle is traveling and the direction of motion of the shock absorbers on the suspension relative to the vehicle body based on the sprung acceleration signal and the unsprung acceleration signal. The second processing module 503 is used to determine the limit difference and rate of change of the unsprung acceleration signal, and to determine the road surface type of the vehicle's driving surface based on the direction of motion and the rate of change of acceleration. The third processing module 504 is configured to obtain an acceleration change rate threshold value and a limit difference threshold value according to a driving mode of the vehicle, a vehicle speed, and roughness and a road surface type of a road surface on which the vehicle travels, and correct the limit difference threshold value based on the acceleration change rate, the roughness, and the driving mode to obtain a second limit difference threshold value; The fourth processing module 505 is configured to determine that the suspension of the vehicle enters a limit stroke when it is detected that the acceleration change rate is greater than the acceleration change rate threshold value, or the limit difference value is greater than the second limit difference threshold value.

[0112] In some optional embodiments, the first processing module 502 is further configured to: obtain sprung mass speed and unsprung mass speed according to the sprung mass acceleration signal and the unsprung mass acceleration signal; calculate a relative speed of the unsprung mass speed relative to the sprung mass speed, and obtain a movement direction of the shock absorber relative to the vehicle body according to a positive or negative type of the relative speed.

[0113] In some optional embodiments, the second processing module 503 is further configured to: obtain an acceleration change trend according to the acceleration change rate; when it is detected that the movement direction is upward movement of the shock absorber relative to the vehicle body and the acceleration change trend is increasing in the movement direction, determine that the road surface type of the road surface on which the vehicle travels is a convex road surface; when it is detected that the movement direction is downward movement of the shock absorber relative to the vehicle body and the acceleration change trend is increasing in the movement direction, determine that the road surface type of the road surface on which the vehicle travels is a pit road surface.

[0114] In some optional embodiments, the third processing module 504 is further configured to: query a preset threshold table based on the driving mode, the vehicle speed, and the roughness to obtain an acceleration change rate threshold value and a limit difference threshold value; correct the acceleration change rate threshold value and the limit difference threshold value according to the road surface type to obtain an acceleration change rate threshold value and a limit difference threshold value.

[0115] In some optional embodiments, the third processing module 504 is further configured to: determine whether the road surface type is a convex road surface or a pit road surface; if the road surface type is a convex road surface or a pit road surface, take the acceleration change rate threshold value as the acceleration change rate threshold value, and take the limit difference threshold value as the limit difference threshold value; if the road surface type is not a convex road surface or a pit road surface, increase absolute values of the acceleration change rate threshold value and the limit difference threshold value to obtain an acceleration change rate threshold value and a limit difference threshold value.

[0116] In some optional embodiments, after the limit difference threshold value is obtained, the third processing module 504 is further configured to: when it is detected that the acceleration change rate is less than a first acceleration change rate threshold, or, the roughness is greater than a first roughness threshold, or, the driving mode is a sport mode, increasing the absolute value of the limit difference threshold; when it is detected that the acceleration change rate is greater than a second acceleration change rate threshold, or, the roughness is less than a second roughness threshold, or, the driving mode is a comfort mode, decreasing the absolute value of the limit difference threshold; wherein the second acceleration change rate threshold is greater than the first acceleration change rate threshold, and the second roughness threshold is less than the first roughness threshold.

[0117] In some optional embodiments, after determining that the vehicle suspension enters the limit travel, the fourth processing module 505 is further configured to: determine a target control current of the shock absorber; adjust the damping force of the shock absorber based on the target control current.

[0118] The limit travel identification device for the vehicle suspension provided by the embodiments of the present application can perform the limit travel identification method for the vehicle suspension provided by any of the embodiments of the present application, and has the corresponding function modules and beneficial effects of performing the method. The further function description of the above-mentioned various modules and units is the same as that of the corresponding embodiments, which will not be described here.

[0119] Figure 6 A structural schematic diagram of an electronic device provided by an embodiment of the present application.

[0120] The following will be specifically described with reference to Figure 6 which shows a structural schematic diagram of an electronic device suitable for being used to implement the electronic device in the embodiments of the present application. The electronic device can include a processor (for example, a central processor, a graphics processor, etc.) 601, which can perform various appropriate actions and processes according to programs stored in a read-only memory (ROM) 602 or programs loaded from a storage 608 into a random access memory (RAM) 603. In the RAM 603, various programs and data required for the operation of the electronic device are also stored. The processor 601, the ROM 602, and the RAM 603 are connected to each other through a bus 604. An input / output (I / O) interface 605 is also connected to the bus 604.

[0121] Generally, the following devices can be connected to the I / O interface 605: an input device 606 including, for example, a touch screen, a touchpad, a keyboard, a mouse, a camera, a microphone, an accelerometer, a gyroscope, etc.; an output device 607 including, for example, a liquid crystal display (LCD), a speaker, a vibrator, etc.; a storage 608 including, for example, a magnetic tape, a hard disk, etc.; and a communication device 609. The communication device 609 can allow the electronic device to communicate with other devices wirelessly or by wire to exchange data. Although Figure 6Electronic devices are shown with various apparatuses, but it should be understood that not all of the illustrated apparatuses are required, and more or fewer apparatuses can alternatively be implemented.

[0122] In particular, the processes described above with reference to the flowcharts can be implemented as a computer software program according to embodiments of the present application. For example, embodiments of the present application include a computer program product comprising a computer program carried on a non-transitory computer-readable medium, the computer program containing program code for performing the methods illustrated by the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via the communication apparatus 609, or installed from the memory 608, or installed from the ROM 602. When the computer program is executed by the processor 601, the above-mentioned functions defined in the vehicle suspension limit travel identification method of embodiments of the present application are performed.

[0123] Figure 6 The electronic device shown is merely an example and should not impose any limitation on the functions and use range of embodiments of the present application.

[0124] Embodiments of the present application also provide a computer-readable storage medium, the above-mentioned method according to embodiments of the present application can be implemented in hardware or firmware, or be implemented as computer code that can be recorded on a storage medium, or be implemented by computer code originally stored in a remote storage medium or a non-transitory machine-readable storage medium and to be stored in a local storage medium through network download, so that the method described herein can be processed by such software stored on a storage medium using a general-purpose computer, a special-purpose processor, or programmable or special-purpose hardware. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only memory, a random access memory, a flash memory, a hard disk or a solid state disk, etc.; further, the storage medium can also include a combination of the above-mentioned types of memories. It can be understood that the computer, processor, microprocessor controller or programmable hardware includes a storage component that can store or receive software or computer code, when the software or computer code is accessed and executed by the computer, processor or hardware, the vehicle suspension limit travel identification method shown in the above-mentioned embodiments is implemented.

[0125] Part of the present application can be applied as a computer program product, for example, computer program instructions, when executed by a computer, through the operation of the computer, can invoke or provide the method and / or technical solutions according to the present application. Those skilled in the art should understand that the form of computer program instructions in computer readable medium includes but is not limited to source files, executable files, installation package files and the like, and accordingly, the way of computer program instructions executed by computer includes but is not limited to: the computer directly executes the instructions, or the computer compiles the instructions and then executes the corresponding compiled program, or the computer reads and executes the instructions, or the computer reads and installs the instructions and then executes the corresponding installed program. Here, the computer readable medium can be any available computer readable storage medium or communication medium accessible to the computer.

[0126] Although the embodiments of the present application are described in conjunction with the drawings, various modifications and changes can be made by those skilled in the art without departing from the spirit and scope of the present application, and such modifications and changes fall within the scope defined by the appended claims.

Claims

1. A method for identifying the limit travel of a vehicle suspension, characterized in that, The method includes: Acquire the vehicle's driving mode, vehicle speed, and the sprung and unsprung acceleration signals of the suspension; Based on the sprung acceleration signal and the unsprung acceleration signal, the roughness of the road surface on which the vehicle travels and the direction of motion of the shock absorber on the suspension relative to the vehicle body are determined. Determine the limit difference and rate of change of the unsprung acceleration signal, and determine the road surface type of the vehicle's travel surface based on the direction of motion and the rate of change of acceleration; Based on the vehicle's driving mode, speed, and the roughness and type of the road surface, the acceleration change rate threshold and limit difference threshold are obtained. When the rate of change of acceleration is detected to be greater than the rate of change of acceleration threshold, or when the limit difference is greater than the limit difference threshold, it is determined that the vehicle suspension has entered its limit travel.

2. The method for identifying the limit travel of a vehicle suspension according to claim 1, characterized in that, The process of obtaining the acceleration change rate threshold and limit difference threshold based on the vehicle's driving mode, speed, and the roughness and type of the road surface includes: Based on the driving mode, the vehicle speed and the roughness, a preset threshold table is consulted to obtain the acceleration change rate threshold value and the limit difference threshold value. Based on the road surface type, the acceleration change rate threshold and the limit difference threshold are corrected to obtain the acceleration change rate threshold and the limit difference threshold.

3. The method for identifying the limit travel of a vehicle suspension according to claim 2, characterized in that, The step of correcting the acceleration change rate threshold and the limit difference threshold based on the road surface type to obtain the acceleration change rate threshold and the limit difference threshold includes: Determine whether the road surface type is a raised road surface or a pothole road surface; If the road surface type is a raised road surface or a pothole road surface, then the acceleration change rate threshold value is used as the acceleration change rate threshold value, and the limit difference threshold value is used as the limit difference threshold value. If the road surface type is not a raised road surface or a pothole road surface, then increase the absolute values ​​of the acceleration change rate threshold and the limit difference threshold to obtain the acceleration change rate threshold and the limit difference threshold.

4. The method for identifying the limit travel of a vehicle suspension according to claim 3, characterized in that, The determination of the road surface type based on the direction of motion and the rate of change of acceleration includes: Based on the rate of change of acceleration, the trend of acceleration change is obtained; When the direction of motion is detected as the shock absorber moving upward relative to the vehicle body and the acceleration changes in the direction of motion as increasing, the road surface type of the vehicle's driving surface is determined to be a raised road surface. When the direction of motion is detected as the shock absorber moving downward relative to the vehicle body and the acceleration trend is increasing in the direction of motion, the road surface type of the vehicle's driving surface is determined to be a pothole road surface.

5. The method for identifying the limit travel of a vehicle suspension according to claim 3, characterized in that, After obtaining the limit difference threshold, the method further includes: When the acceleration change rate is detected to be less than the first acceleration change rate threshold, or the roughness is greater than the first roughness threshold, or the driving mode is sport mode, the absolute value of the limit difference threshold is increased. When the acceleration change rate is detected to be greater than the second acceleration change rate threshold, or the roughness is less than the second roughness threshold, or the driving mode is comfort mode, the absolute value of the limit difference threshold is reduced; wherein the second acceleration change rate threshold is greater than the first acceleration change rate threshold, and the second roughness threshold is less than the first roughness threshold.

6. The method for identifying the limit travel of a vehicle suspension according to any one of claims 1-5, characterized in that, Based on the sprung acceleration signal and the unsprung acceleration signal, the motion direction of the shock absorber on the suspension relative to the vehicle body is determined, including: Based on the sprung acceleration signal and the unsprung acceleration signal, the sprung velocity and the unsprung velocity are obtained; Calculate the relative velocity between the unsprung velocity and the sprung velocity, and determine the direction of motion of the shock absorber relative to the vehicle body based on the sign of the relative velocity.

7. The method for identifying the limit travel of a vehicle suspension according to any one of claims 1-5, characterized in that, After determining that the vehicle suspension has reached its limit travel, the method further includes: Determine the target control current for the shock absorber; The damping force of the shock absorber is adjusted based on the target control current.

8. A limit travel recognition device for vehicle suspension, characterized in that, The device includes: The acquisition module is used to acquire the vehicle's driving mode, vehicle speed, and the sprung and unsprung acceleration signals of the suspension. The first processing module is used to determine the roughness of the road surface on which the vehicle travels and the direction of motion of the shock absorbers on the suspension relative to the vehicle body based on the sprung acceleration signal and the unsprung acceleration signal. The second processing module is used to determine the limit difference and rate of change of the unsprung acceleration signal, and to determine the road surface type of the vehicle's driving surface based on the direction of motion and the rate of change of acceleration. The third processing module is used to obtain an acceleration change rate threshold and a limit difference threshold based on the vehicle's driving mode, vehicle speed, and the roughness and road surface type, and to correct the limit difference threshold based on the acceleration change rate, the roughness, and the driving mode to obtain a second limit difference threshold. The fourth processing module is used to determine that the vehicle suspension has entered its limit travel when the rate of change of acceleration is detected to be greater than the rate of change of acceleration threshold, or when the limit difference is greater than the second limit difference threshold.

9. An electronic device, characterized in that, include: A memory and a processor are communicatively connected, the memory stores computer instructions, and the processor executes the computer instructions to perform the vehicle suspension limit travel identification method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions for causing the computer to execute the vehicle suspension limit travel identification method according to any one of claims 1 to 7.

11. A computer program product, characterized in that, Includes computer instructions for causing a computer to execute the vehicle suspension limit travel identification method according to any one of claims 1 to 7.

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