Semi-active suspension vehicle body acceleration control method

Abstract

The invention provides a semi-active suspension vehicle body acceleration control method which comprises the following steps: S1, acquiring a signal and processing the signal; s2, inputting the processed signal into an expert database of a control system, and determining parameters kc and cnom required for improving an acceleration control algorithm based on the obtained vehicle body motion information and suspension motion information of the vehicle and the pre-established expert database; s3, inputting the parameters kc and cnom and the obtained motion information of the vehicle body and the suspension into a damping calculation module in a control system, and calculating damping by using an improved acceleration control algorithm formula; the improved acceleration control calculation formula is # imgabs0 # imgabs1 #, when kc is 0, the output damping value is cnom, and at the moment, the actual control strategy is a passive suspension; and when kc > + infinity, the control strategy is biased to switch type damping control of acceleration control. Switching type damping control is optimized into continuous damping control, the performance of the shock absorber is fully used, jerk increase caused by damping switching is reduced, and comfort is improved.

Description

Technical Field

[0001] The invention relates to the field of semi-active suspension vehicle bodies, and in particular to an acceleration control method for a semi-active suspension vehicle body. Background Art

[0002] In the prior art, semi-active suspension usually meets the requirements of comfort and handling by adjusting damping, and has the advantages of moderate cost and good control effect. Currently, it has been rapidly popularized in vehicle suspension systems.

[0003] However, the effectiveness of semi-active suspension not only depends on the design of its own damping characteristic curve, but is also highly related to the setting of the control algorithm.

[0004] The existing semi-active suspension body acceleration control algorithm is a switch-type algorithm, which can improve comfort under conditions with high vibration frequencies, but the damping value of this switch-type algorithm is only selected between the maximum and minimum, which cannot fully utilize the shock absorber performance.

[0005] At the same time, the rapid switching of the damping value of the switch algorithm between the maximum and minimum points will lead to an increase in jerkiness (acceleration), which will affect the riding comfort of passengers to a certain extent.

[0006] Therefore, in order to solve the shortcomings of the vehicle body acceleration control algorithm, which has limited control effect and cannot fully utilize the damping adjustment characteristics of the shock absorber, the inventor of the present application has designed a semi-active suspension vehicle body acceleration control method in order to overcome the above technical problems. Summary of the invention

[0007] The technical problem to be solved by the present invention is to provide a semi-active suspension body acceleration control method in order to overcome the defects of the vehicle body acceleration control algorithm in the prior art that the control effect is limited and the damping adjustment characteristics of the shock absorber cannot be fully utilized.

[0008] The present invention solves the above technical problems through the following technical solutions:

[0009] A semi-active suspension vehicle body acceleration control method, characterized in that the semi-active suspension vehicle body acceleration control method comprises the following steps:

[0010] S1, collect signals and process them;

[0011] S2. Input the processed signal into the expert database of the control system, and determine the parameters k required to improve the acceleration control algorithm based on the acquired vehicle body motion information, suspension motion information and the pre-established expert database. c ,c nom ;

[0012] S3, parameter kc ,c nom The obtained vehicle body and suspension motion information is input into the damping calculation module in the control system, and the damping is calculated using the improved acceleration control algorithm formula;

[0013] The improved acceleration control calculation formula is:

[0014]

[0015] Among them, c in is the target damping of the semi-active suspension; c min ,c max They are the minimum and maximum adjustable damping of the semi-active suspension; is the sprung acceleration; is the relative speed of the suspension movement; k c ,c nom To improve the parameters of the acceleration control algorithm, when k c When it is 0, the output damping value is c nom , at this time the actual control strategy is passive suspension; when k c →+∞, the control strategy tends to the switching damping control of acceleration control.

[0016] According to one embodiment of the present invention, the control system includes: a signal processing module, an expert database, a damping calculation module and a current output module, wherein the signal processing module is used for signal processing, and after signal processing, outputs the suspension movement relative speed and road roughness signal to the expert database;

[0017] The expert database outputs the parameters k required by the control algorithm c ,c nom To the damping calculation module, the damping calculation module is used to calculate the damping value that needs to be output under the current working conditions and transmit it to the current output module.

[0018] According to one embodiment of the present invention, step S1 includes:

[0019] S 11 , using the signal acquisition system to obtain vehicle body motion information and suspension motion information;

[0020] S 12 , input the collected signals into the signal processing module of the control system, and after processing the signals of the suspension height sensor, obtain the relative speed of the suspension movement and the road roughness information.

[0021] According to one embodiment of the present invention, the step S 11 The signal acquisition system includes sensors and CAN communication modules.

[0022] According to an embodiment of the present invention, the sensor includes a plurality of suspension height sensors and a vehicle body three-axis acceleration sensor.

[0023] According to an embodiment of the present invention, the vehicle body three-axis acceleration sensor measures acceleration signals of the vehicle body in vertical, roll and pitch directions.

[0024] According to one embodiment of the present invention, the step S 12 In the equation, the vertical acceleration at the connection between the upper end of the suspension and the vehicle body is obtained by converting the model of the vehicle body acceleration sensor, and the formula is:

[0025]

[0026] in, They are the vertical accelerations of the vehicle body at the four suspension points: left front, right front, right rear, and left rear; They are the vertical, roll and pitch accelerations of the vehicle body measured by the three-axis acceleration sensors of the vehicle body; a and b are the distances from the vehicle body acceleration sensors to the left and right shock absorbers; l1 and l2 are the distances from the vehicle body acceleration sensors to the front and rear axles.

[0027] According to an embodiment of the present invention, the expert database in step S2 includes different vehicle speeds, road roughness and corresponding parameters k c ,x nom The relationship between the parameter k c ,c nom Used in control algorithm calculations for damping.

[0028] According to one embodiment of the present invention, the semi-active suspension vehicle body acceleration control method further comprises the following steps:

[0029] S4. In the current output module of the control system, according to the calculated damping value and the obtained relative speed of the suspension movement, based on the preset shock absorber current-damping characteristic curve table, the shock absorber current to be output is interpolated and output to the actual shock absorber.

[0030] The positive and progressive effects of the present invention are:

[0031] The semi-active suspension vehicle acceleration control method of the present invention optimizes the switch-type damping control to continuous damping control, fully utilizes the shock absorber performance, reduces the increase in jerkiness caused by damping switching, and improves comfort. At the same time, the acceleration control method also expands the algorithm's ability to adjust the sprung acceleration and suspension travel. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The above and other features, properties and advantages of the present invention will become more apparent through the following description in conjunction with the accompanying drawings and embodiments, in which the same reference numerals always represent the same features, wherein:

[0033] Figure 1 The figure is a flow chart of the semi-active suspension vehicle body acceleration control method of the present invention.

[0034] Figure 2 It is a system schematic diagram of the semi-active suspension vehicle body acceleration control method of the present invention.

[0035] Figure 3 The figure is a schematic diagram of the configuration of sensors in the semi-active suspension vehicle body acceleration control method of the present invention.

[0036] Figure 4 It is a schematic diagram of a vehicle model in the semi-active suspension vehicle body acceleration control method of the present invention. DETAILED DESCRIPTION

[0037] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0038] Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Reference will now be made in detail to preferred embodiments of the present invention, examples of which are shown in the accompanying drawings. Wherever possible, the same reference numerals will be used throughout the drawings to represent the same or similar parts.

[0039] Furthermore, although the terms used in the present invention are selected from well-known and commonly used terms, some terms mentioned in the present invention specification may be selected by the applicant at his or her discretion, and their detailed meanings are explained in the relevant parts of the description of this document.

[0040] Furthermore, it is required that the present invention be understood not only by the actual terms used but also by the meanings connoted by each term.

[0041] like Figures 1 to 4 As shown, the present invention discloses a semi-active suspension vehicle body acceleration control method, which comprises the following steps:

[0042] Step S1: collect signals and process them.

[0043] Preferably, the step S1 includes:

[0044] Step S 11 , use the signal acquisition system to obtain vehicle body motion information and suspension motion information.

[0045] The step S 11The signal acquisition system includes a sensor and a CAN communication module. The sensor is arranged at a position such as Figure 3 As shown, the sensor includes a plurality of suspension height sensors (eg, four suspension height sensors) and a vehicle body three-axis acceleration sensor.

[0046] Here, the vehicle acceleration sensor is installed on the vehicle body, and there is no requirement for the installation method. There is no requirement for the installation position and method of the suspension height sensor, as long as it can achieve the function of measuring the suspension height.

[0047] The CAN communication module is used to obtain the vehicle speed signal from the vehicle CAN. The vehicle body three-axis acceleration sensor measures the acceleration signals of the vehicle body in vertical, roll and pitch directions.

[0048] Step S 12 , input the collected signals into the signal processing module of the control system, and after processing the signals of the suspension height sensor, obtain the relative speed of the suspension movement and the road roughness information.

[0049] Preferably, the step S 12 In the equation, the vertical acceleration at the connection between the upper end of the suspension and the vehicle body is obtained by converting the model of the vehicle body acceleration sensor, and the formula is:

[0050]

[0051] in, They are the vertical accelerations of the vehicle body at the four suspension points: left front, right front, right rear, and left rear; They are the vertical, roll and pitch accelerations of the vehicle body measured by the three-axis acceleration sensors of the vehicle body; a and b are the distances from the vehicle body acceleration sensors to the left and right shock absorbers; l1 and l2 are the distances from the vehicle body acceleration sensors to the front and rear axles.

[0052] Step S2: Input the processed signal into the expert database of the control system, and determine the parameter k required for improving the acceleration control algorithm based on the acquired vehicle body motion information, suspension motion information and the pre-established expert database. c ,c nom .

[0053] The expert database stores the control parameters obtained from experiments that can achieve the optimal control effect under different working conditions (vehicle speed, road roughness). The current working condition obtained in the previous step is input into the expert database to query the control parameter k that should be selected at present. c ,c nom .

[0054] In the semi-active suspension vehicle body acceleration control method of the present invention, the expert database is established by:

[0055] Use the orthogonal experimental method to set different working conditions (such as vehicle speed, road roughness, vehicle acceleration), change the control parameters (such as k c ,c nom ) to conduct experiments and obtain the control parameters that can achieve the optimal control effect under various working conditions.

[0056] On this basis, professional driving evaluators intervene and adjust the control parameters according to the vehicle driving style (such as sports, comfort). nom A larger value is more suitable for a sporty driving style. nom When the value is adjusted to a smaller value, it is more suitable for a comfortable driving style. c The value is too large. When the working condition is relatively stable, k c The value is too small, and the adjusted control parameters are obtained.

[0057] The values ​​of the test conditions (such as vehicle speed, road roughness, and vehicle acceleration) are normalized to eliminate the influence of different dimensions. The normalized values ​​of the test conditions (such as vehicle speed, road roughness, and vehicle acceleration) and the adjusted control parameters (such as k c ,c nom ) to obtain the working conditions (such as vehicle speed, road roughness, vehicle acceleration) and control parameters (such as k c ,c nom The expert database is established based on the obtained corresponding relationship.

[0058] Preferably, the expert database in step S2 includes different vehicle speeds, road roughness and corresponding parameters k c ,c nom The relationship between the parameter k c ,c nom Used in control algorithm calculations for damping.

[0059] Here, the corresponding parameter k c ,c nom " means that under certain working conditions (vehicle speed, road roughness), there is a set of parameters k that achieve the optimal control effect c ,c nom , this correspondence can be determined through experiments.

[0060] Step S3: Set the parameter k c ,c nom The obtained vehicle body and suspension motion information is input into the damping calculation module in the control system, and the damping is calculated using the improved acceleration control algorithm formula.

[0061] Based on Figure 4 The vehicle model shown is used for explanation, and the improved acceleration control calculation formula is:

[0062]

[0063] Among them, c in is the target damping of the semi-active suspension; c min ,c max They are the minimum and maximum adjustable damping of the semi-active suspension; is the sprung acceleration; is the relative speed of the suspension movement; k c ,c nom To improve the parameters of the acceleration control algorithm, when k c When it is 0, the output damping value is c nom , at this time the actual control strategy is passive suspension; when k c →+∞, the control strategy tends to the switching damping control of acceleration control.

[0064] Preferably, the semi-active suspension vehicle body acceleration control method further comprises the following steps:

[0065] S4. In the current output module of the control system, according to the calculated damping value and the obtained relative speed of the suspension movement, based on the preset shock absorber current-damping characteristic curve table, the shock absorber current to be output is interpolated and output to the actual shock absorber. The shock absorber current-damping characteristic curve table includes the damping characteristics of the shock absorber under different input currents.

[0066] Preferably, the control system includes: a signal processing module, an expert database, a damping calculation module and a current output module. The signal processing module is used for signal processing. After signal processing, the relative speed of the suspension movement and the road roughness signal are output to the expert database. The expert database outputs the parameters k required by the control algorithm. c ,c nom To the damping calculation module, the damping calculation module is used to calculate the damping value that needs to be output under the current working conditions and transmit it to the current output module.

[0067] In this embodiment, the signal processing module is used for signal processing. The input of the module is the sensor signal and the CAN communication signal. After signal processing, the module outputs the suspension movement relative speed and road roughness signal to the expert database.

[0068] The input of the expert database is the relative speed of the suspension movement and the road roughness signal, and the output is the parameter k required by the control algorithm. c ,c nomTo the damping calculation module. The expert database can also be called an "experience database" or "knowledge base", which stores empirical data summarized from experiments. In the experiment, based on specific working conditions (such as vehicle speed, road roughness), the control parameter k is changed. c ,c nom The experiment is conducted to obtain the control parameters that can achieve the best effect under the working condition, and the control parameters are stored as experience data in the expert database. Different working conditions have their own control parameters that can achieve the best effect.

[0069] The damping calculation module is used to calculate the damping value that needs to be output under the current working condition. The module input is the control algorithm parameter k c ,c nom , the relative speed of the suspension movement, the sprung acceleration (i.e., the acceleration at the connection between the upper end of the frame and the vehicle body), the module calculates the required damping value according to the formula in step S3 and outputs it to the current output module.

[0070] The current output module has two functions: the first function is that the current output module stores the corresponding relationship data of the shock absorber current and the shock absorber damping. Here, the damping size of the semi-active shock absorber is controlled by the current size. Generally speaking, there is a corresponding relationship that the larger the current, the larger the damping. The required damping value was input in the previous step, and the required output current size can be calculated based on the data stored in the module. The second function is to output the current to the semi-active shock absorber after calculating the required output current size.

[0071] In summary, the semi-active suspension vehicle acceleration control method of the present invention optimizes the switch-type damping control to continuous damping control, fully utilizes the shock absorber performance, reduces the increase in jerkiness caused by damping switching, and improves comfort. At the same time, the acceleration control method also expands the algorithm's ability to adjust the sprung acceleration and suspension travel.

[0072] For those skilled in the art, the above invention disclosure is only used as an example and does not constitute a limitation of the present application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements and amendments to the present application. Such modifications, improvements and amendments are suggested in the present application, so such modifications, improvements and amendments still belong to the spirit and scope of the exemplary implementation of the present application.

[0073] At the same time, the present application uses specific words to describe the embodiments of the present application. For example, "one embodiment", "an embodiment", and / or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more in different positions in this specification does not necessarily refer to the same embodiment. In addition, some features, structures or characteristics in one or more embodiments of the present application can be appropriately combined.

[0074] Similarly, it should be noted that in order to simplify the description disclosed in this application and thus help understand one or more embodiments of the invention, in the foregoing description of the embodiments of the present application, multiple features are sometimes merged into one embodiment, drawing or description thereof. However, this disclosure method does not mean that the subject matter of this application requires more features than those mentioned in the claims. In fact, the features of the implementation are less than all the features of the single implementation disclosed above. In some implementations, numbers are used to describe the number of components and attributes. It should be understood that such numbers used to describe the implementations are modified in some examples using the modifiers "approximately", "approximately" or "substantially".

[0075] Although the specific embodiments of the present invention are described above, it should be understood by those skilled in the art that these are only examples, and the protection scope of the present invention is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but these changes and modifications all fall within the protection scope of the present invention.

Claims

1. A semi-active suspension vehicle body acceleration control method, characterized in that: The semi-active suspension vehicle body acceleration control method comprises the following steps: S1, collect signals and process them; S2. Input the processed signal into the expert database of the control system, and determine the parameters k required to improve the acceleration control algorithm based on the acquired vehicle body motion information, suspension motion information and the pre-established expert database. c ,c nom ; S3, parameter k c ,c nom The obtained vehicle body and suspension motion information is input into the damping calculation module in the control system, and the damping is calculated using the improved acceleration control algorithm formula; The improved acceleration control calculation formula is: Among them, c in is the target damping of the semi-active suspension; c min ,c max They are the minimum and maximum adjustable damping of the semi-active suspension; is the sprung acceleration; is the relative speed of the suspension movement; k c ,c nom To improve the parameters of the acceleration control algorithm, when k c When it is 0, the output damping value is c nom , at this time the actual control strategy is passive suspension; when k c →+∞, the control strategy tends to the switching damping control of acceleration control.

2. The semi-active suspension vehicle body acceleration control method according to claim 1, characterized in that: The control system comprises: a signal processing module, an expert database, a damping calculation module and a current output module, wherein the signal processing module is used for signal processing, and after signal processing, outputs the suspension movement relative speed and road surface roughness signals to the expert database; The expert database outputs the parameters k required by the control algorithm c ,c nom To the damping calculation module, the damping calculation module is used to calculate the damping value that needs to be output under the current working conditions and transmit it to the current output module.

3. The semi-active suspension vehicle body acceleration control method according to claim 1, characterized in that: The step S1 includes: S 11 , using the signal acquisition system to obtain vehicle body motion information and suspension motion information; S 12 , input the collected signals into the signal processing module of the control system, and after processing the signals of the suspension height sensor, obtain the relative speed of the suspension movement and the road roughness information.

4. The semi-active suspension vehicle body acceleration control method according to claim 3, characterized in that: The step S 11 The signal acquisition system includes sensors and CAN communication modules.

5. The semi-active suspension vehicle body acceleration control method according to claim 4, characterized in that: The sensors include a plurality of suspension height sensors and a vehicle body three-axis acceleration sensor.

6. The semi-active suspension vehicle body acceleration control method according to claim 5, characterized in that: The vehicle body three-axis acceleration sensor measures acceleration signals of the vehicle body in vertical, roll and pitch directions.

7. The semi-active suspension vehicle body acceleration control method according to claim 3, characterized in that: The step S 12 In the equation, the vertical acceleration at the connection between the upper end of the suspension and the vehicle body is obtained by converting the model of the vehicle body acceleration sensor, and the formula is: in, They are the vertical accelerations of the vehicle body at the four suspension points: left front, right front, right rear, and left rear; They are the vertical, roll and pitch accelerations of the vehicle body measured by the three-axis acceleration sensors of the vehicle body; a and b are the distances from the vehicle body acceleration sensors to the left and right shock absorbers; l1 and l2 are the distances from the vehicle body acceleration sensors to the front and rear axles.

8. The semi-active suspension vehicle body acceleration control method according to claim 1, characterized in that: The expert database in step S2 includes different vehicle speeds, road roughness and corresponding parameters k c ,c nom The relationship between the parameter k c ,c nom Used in control algorithm calculations for damping.

9. The semi-active suspension vehicle body acceleration control method according to claim 1, characterized in that: The semi-active suspension vehicle body acceleration control method further comprises the following steps: S4. In the current output module of the control system, according to the calculated damping value and the obtained relative speed of the suspension movement, based on the preset shock absorber current-damping characteristic curve table, the shock absorber current to be output is interpolated and output to the actual shock absorber.

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