DRIVING PATTERN REGENERATIVE BRAKING METHOD OF VEHICLE
20240217345 ยท 2024-07-04
Inventors
Cpc classification
International classification
Abstract
A driving pattern regenerative braking method of a vehicle includes: collecting and inputting driving data, extracting deceleration data through preprocessing the driving data, clustering the deceleration data and removing outliers, calculating a deceleration rate change and an inter-vehicle distance to a vehicle in front from clustered data, deriving a quadratic equation of the deceleration rate change and the distance to the vehicle in front through polynomial regression, determining whether a predetermined condition is satisfied, and if so, modifying a regenerative braking system of the vehicle based on the quadratic equation, all of the above steps being performed by a controller. The method may further include calculating orthogonal distances and removing deceleration data furthest away in orthogonal distance from the quadratic equation if the predetermined condition is not satisfied.
Claims
1. A driving pattern regenerative braking method of a vehicle, the method comprising: collecting and inputting, by a controller, driving data; extracting, by the controller, deceleration data through preprocessing the driving data; clustering, by the controller, the deceleration data and removing outliers; calculating, by the controller, a deceleration rate change and an inter-vehicle distance to a vehicle in front from clustered data; deriving, by the controller, a quadratic equation of the deceleration rate change and the distance to the vehicle in front through polynomial regression; determining, by the controller, whether the derived quadratic equation satisfies a predetermined condition; and modifying by the controller, a regenerative braking system of the vehicle based on the quadratic equation being satisfied.
2. The method of claim 1, further comprising: calculating orthogonal distances and removing deceleration data furthest away in orthogonal distance from the quadratic equation based on the predetermined condition not being satisfied.
3. The method of claim 2, further comprising determining whether a number of data sets is equal to or greater than the number of a predetermined set after removing the deceleration data furthest away in orthogonal distance from the quadratic equation.
4. The method of claim 3, wherein the extracting of deceleration data through preprocessing the driving data comprises: extracting the deceleration data into a plurality of sets; calculating the deceleration rate change and the inter-vehicle distance to the vehicle in front during a deceleration state; and extracting the deceleration mate change and the inter-vehicle distance to the vehicle in front for the plurality of sets of deceleration data.
5. The method of claim 4, wherein the plurality of sets is 42 sets.
6. The method of claim 4, wherein the extracting of the deceleration rate change and the inter-vehicle distance to the vehicle in front for the plurality of sets of deceleration data comprises extracting driver's braking characteristic data.
7. The method of claim 6, wherein the extracting of the driver's braking characteristic data comprises extracting the driver's braking characteristic data based on the inter-vehicle distance to the vehicle in front and the deceleration rate change.
8. The method of claim 7, wherein the extracting of the deceleration rate change and the inter-vehicle distance to the vehicle in front for the plurality of sets of deceleration data comprises filtering the extracted driver's braking characteristic data after extracting the driver's braking characteristic data.
9. The method of claim 8, wherein the filtering of the extracted driver's braking characteristic data comprises excluding the driver's braking characteristic data where lateral acceleration increases excessively during vehicle turning.
10. The method of claim 9, wherein the extracting of the deceleration rate change and the inter-vehicle distance to the vehicle in front for the plurality of sets of deceleration data comprises classifying the filtered driver's braking characteristic data after filtering the extracted driver's braking characteristic data.
11. The method of claim 10, wherein the classifying of the filtered driver's braking characteristic data comprises classifying the data based on longitudinal acceleration increase or decrease resulting from changes in gradient.
12. The method of claim 11, wherein the clustering of the deceleration data and removing outliers comprises applying a clustering algorithm combining a DBSCAN (density-based spatial clustering of applications with noise) method and a DTW (dynamic time warping) method.
13. The method of claim 12, wherein the calculating of deceleration rate change and inter-vehicle distance to the vehicle in front from clustered data comprises: removing outlier deceleration data sets by clustering based on brake pedal stroke and relative speed with the vehicle in front as features during flat terrain driving; and classifying the deceleration data forming the cluster, with the exclusion of the outlier deceleration data sets, as driver's braking characteristic data.
14. The method of claim 13, wherein the calculating of deceleration rate change and inter-vehicle distance to the vehicle in front from clustered data comprises: removing outlier deceleration data sets by clustering based on brake pedal stroke and relative speed with the vehicle in front as features during downhill driving; and classifying the deceleration data forming the cluster, with the exclusion of the outlier deceleration data sets, as driver's braking characteristic data.
15. The method of claim 14, wherein the deriving of a quadratic equation of the deceleration rate change and the distance to the vehicle in front through polynomial regression comprises performing the polynomial regression on clustered flat terrain and downhill deceleration data sets to drive the quadratic equation:
16. The method of claim 15, wherein the deriving of a quadratic equation of the deceleration rate change and the distance to the vehicle in front through polynomial regression comprises evaluating whether the derived quadratic equation exhibits the characteristic of increasing the deceleration rate change as the inter-vehicle distance decreases, based on the predetermined condition.
17. The method of claim 16, wherein the predetermined condition comprises:
18. The method of claim 17, wherein the reflecting of the quadratic equation to a smart regenerative braking system for control comprises: applying the driver's braking characteristic data obtained through clustering to the smart regenerative braking system; and implementing a braking start point and braking intensity to match the driver's braking pattern.
19. The method of claim 18, wherein the removing of deceleration data furthest away in orthogonal distance from the quadratic equation comprises re-collecting and re-inputting the driving data based on the number of deceleration data falling below a predetermined sei after the removal of the deceleration data farthest away in orthogonal distance from the quadratic equation.
20. A non-transitory computer readable medium containing program instructions executed by a processor, the computer readable medium comprising: program instructions that collect and input driving data; program instructions that extract deceleration data through preprocessing the driving data; program instructions that cluster the deceleration data and remove outliers; program instructions that calculate a deceleration rate change and an inter-vehicle distance to a vehicle in front from clustered data; program instructions that derive a quadratic equation of the deceleration rate change and the distance to the vehicle in from through polynomial regression; program instructions that determine whether the derived quadratic equation satisfies a predetermined condition; and program instructions that modify a regenerative braking system of a vehicle being driven based on the quadratic equation being satisfied.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] Various embodiments of the present disclosure are described with reference to the accompanying drawings, and similar reference numbers are used to collectively refer to similar components. In the following descriptions, presented for explanatory purposes, numerous specific details are provided to offer a comprehensive understanding of one or more embodiments. However, it will be evident that such embodiments can be implemented without these specific details.
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DETAILED DESCRIPTION OF THE DISCLOSURE
[0047] It is understood that the term vehicle or vehicular or other similar term as used herein is inclusive of motor vehicles in general such as passenger automobiles including sports utility vehicles (SUV), buses, trucks, various commercial vehicles, watercraft including a variety of boats and ships, aircraft, and the like, and includes hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles and other alternative fuel vehicles (e.g. fuels derived from resources other than petroleum). As referred to herein, a hybrid vehicle is a vehicle that has two or more sources of power, for example both gasoline-powered and electric-powered vehicles.
[0048] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. As used herein, the singular forms a, an and the are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms comprises and/or comprising, when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein the term and/or includes any and all combinations of one or more of the associated listed items. Throughout the specification, unless explicitly described to the contrary, the word comprise and variations such as comprises or comprising will be understood to imply the inclusion of stated elements but not the exclusion of any other elements. In addition, the terms unit, -er, -or, and module described in the specification mean units for processing at least one function and operation, and can be implemented by hardware components or software components and combinations thereof.
[0049] Further, the control logic of the present disclosure may be embodied as non-transitory computer readable media on a computer readable medium containing executable program instructions executed by a processor, controller or the like. Examples of computer readable media include, but are not limited to, ROM, RAM, compact disc (CD)-ROMs, magnetic tapes, floppy disks, flash drives, smart cards and optical data storage devices. The computer readable medium can also be distributed in network coupled computer systems so that the computer readable media is stored and executed in a distributed fashion, e.g., by a telematics server or a Controller Area Network (CAN).
[0050] Advantages and features of the present disclosure and methods of accomplishing the same may be understood more readily by reference to the following detailed description of embodiments and the accompanying drawings. The present disclosure may, however, be embodied in many different forms and should not be construed as being limited to the exemplary embodiments set forth herein; rather, these exemplary embodiments are provided so that the present disclosure will be thorough and complete and will fully convey the concept of the disclosure to those skilled in the art, and the present disclosure will only be defined by the appended claims.
[0051] The shapes, sizes, ratios, angles, numbers and the like illustrated in the drawings to describe embodiments of the present disclosure are merely exemplary, and thus, the present disclosure is not limited thereto. Throughout the specification, the same reference numerals refer to the same components. In addition, detailed descriptions of well-known technologies may be omitted in the present disclosure to avoid obscuring the subject matter of the present disclosure. When terms such as comprises. has, includes, or is made up of are used in this specification, it should be understood that unless only is specifically used, additional elements or steps can be included. Unless otherwise explicitly stated, when a component is expressed in the singular form, it is intended to encompass the plural form as well.
[0052] In interpreting the components, it is construed to include a margin of error even in the absence of explicit description.
[0053] When describing the positional relationship, for example, when the relationship between two parts is described as on, on top of. underneath. besides, etc., unless directly or immediately is used, one or more other parts may be located between the two parts.
[0054] Although the terms first, second, and the like are used to describe various components, these components are not limited by these terms. These terms are merely used for distinguishing one component from the other components. Therefore, the first component mentioned hereinafter may be the second component in the technical sense of the present disclosure.
[0055] Throughout the specification, the same reference numerals refer to the same components.
[0056] The sizes and thicknesses of each component shown in the drawings are presented for the convenience of description and are not intended to limit the present disclosure.
[0057] The features of various embodiments of the present disclosure can be combined or assembled, either partially or entirely, in various technical manners such as interlocking and interoperations obvious to those skilled in the art, and each embodiment can be independently implemented or in conjunction with related embodiments.
[0058] Hereinafter, detailed descriptions are made of the embodiments of the present disclosure with reference to the accompanying drawings. The embodiments described below may be applied redundantly as long as they do not conflict with each other.
[0059] With reference to
[0060] Here, based on condition A being satisfied (YES) at step S6, the method proceeds to reflect the quadratic equation to a smart regenerative braking system for control at step S7. In other words, if the condition A (predetermined condition) is satisfied, then the regenerative braking system of the vehicle is modified based on the result of the quadratic equation.
[0061] On the contrary, based on condition A being not satisfied (NO) at step S6, the method proceeds to calculate the orthogonal distance from the quadratic equation to remove the deceleration data furthest away at step S8, and determine whether the number of data sets is equal to or greater than a predetermined set at step S9.
[0062] The above steps S1 through S9 as depicted in
[0063] Hereinafter, each step will be described in detail with reference to
[0064] Collecting and inputting driving data at step S1 may involve collecting actual driving data during the driver's driving and inputting the data into a database.
[0065] Next, extracting deceleration data through preprocessing of driving data at step $2 may involve extracting deceleration data into a plurality of sets from the entire driving data, as shown in
[0066] Here, the plurality of sets may be 42 sets. The deceleration data refers to deceleration data extracted when a vehicle in front is detected. That is, when the driver decelerates in a situation where a vehicle in front is detected, 42 sets of deceleration data are extracted.
[0067] Next, the deceleration rate change and the inter-vehicle distance to the vehicle in front may be calculated during a deceleration stage, as shown in
[0068] Next, the deceleration rate change and the inter-vehicle distance to the vehicle in front may be extracted for multiple sets of deceleration data, as shown in
[0069] Next, driver's braking characteristic data may be extracted as shown in
[0070] Subsequently, the extracted driver's braking characteristic data may be filtered. This involves excluding driver's braking characteristic data where lateral acceleration increases excessively during vehicle turning.
[0071] For example, it may be possible to filter data with an absolute value of lateral acceleration less than 0.07 g as shown in
[0072] Subsequently, the filtered driver's braking characteristic data may be classified. This involves classifying the data based on changes in the longitudinal acceleration due to the gradient.
[0073] For example, downhill data may be classified based on a gradient of ?1%, as shown in
[0074] Alternatively, flat terrain driving data may be classified based on a gradient of 0%, as shown in
[0075] Alternatively, uphill data may be classified based on a gradient of 3% as shown in
[0076] However, these are just examples, and the gradient criteria for classifying downhill, flat terrain, and uphill may vary.
[0077] Next, clustering and removing outliers for the deceleration data at step S3 may be performed by applying a clustering algorithm combining the DBSCAN method and DTW method.
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[0079] The DBSCAN method recognizes a cluster when there are at least the minimum number of data points (minPts) within a specified radius (epsilon) of each other by comparing distances between the data points. Data points outside the radius are determined as outliers.
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[0081] The DTW method is an algorithm for measuring the similarity between two time sequences, primarily used in applications such as speech recognition or pattern recognition. This allows for measuring similarity even when the lengths of the two sequences are different.
[0082] Next, calculating the deceleration rate change and the inter-vehicle distance to the vehicle in front for the clustered data at step $4 is performed.
[0083] In this step, driver's flat terrain braking characteristic data may be initially extracted.
[0084] This step involves removing outlier deceleration data sets by clustering based on brake pedal stroke and relative speed with the vehicle in front as features during flat terrain driving, and classifying the deceleration data forming the cluster, with the exclusion of the outlier deceleration data sets, as driver's braking characteristic data.
[0085] For example, with reference to the graph of deceleration (gradient deceleration) over vehicle speed at the top of
[0086] With reference to the graph of deceleration over the inter-vehicle distance to the vehicle in front presented in the middle of the drawing, as the inter-vehicle distance to the vehicle in front decreases, the deceleration rate change tends to increase. This phenomenon is attributed to the driver's tendency to increase the stroke of the brake pedal on flat terrain as the inter-vehicle distance to the vehicle in front decreases.
[0087] With reference to the graph of vehicle speed over the inter-vehicle distance to the vehicle in front presented at the bottom, it can be observed that the vehicle speed and the inter-vehicle distance to the vehicle in front in driver's braking characteristic data do not exhibit linear characteristics. It can be observed that the deceleration data is scattered in various places around the dotted straight line.
[0088] In this way, the driver's flat terrain braking characteristic data for deceleration is extracted during flat terrain driving as described above.
[0089] Next, driver's downhill braking characteristic data is extracted, as shown in
[0090] This step involves removing outlier deceleration data sets through clustering based on brake pedal stroke and relative speed with the vehicle in front as features during downhill driving, and classifying the deceleration data forming the cluster with the exclusion of the outlier deceleration data sets as driver's braking characteristic data.
[0091] For example, with reference to the graph of deceleration (gradient deceleration) over vehicle speed at the top of
[0092] With reference to the graph of deceleration over the distance to the vehicle in front presented in the middle of the drawing, as the distance to the vehicle in front decreases, the deceleration rate change tends to increase. This phenomenon is attributed to the driver's tendency to increase the stroke of the brake pedal on downhill as the inter-vehicle distance to the vehicle in front decreases.
[0093] With reference to the graph of vehicle speed over the inter-vehicle distance to the vehicle in front presented at the bottom, it can be observed that the vehicle speed and the inter-vehicle distance to the vehicle in front in driver's braking characteristic data exhibit linear characteristics. It can be observed that the deceleration data is marked adjacent to the dotted straight line.
[0094] In this way, the driver's downhill braking characteristic data for deceleration is extracted.
[0095] Deriving a quadratic equation for the deceleration rate change and the distance to the vehicle in front through polynomial regression at step S5 may involves performing polynomial regression on the clustered flat terrain and downhill deceleration data sets, as shown in
[0096] Here, the quadratic equation may be derived on condition A.
[0097] Determining whether condition A is satisfied at step S6 involves verifying whether condition A is satisfied.
[0098] Whether condition A is satisfied is determined as shown in
[0099] Among the soft, medium, and strong driving conditions, the soft stage is the most similar to the driver's pattern.
[0100] As a result, the quadratic equation y=0.00018?x.sup.2+0.04247?x?3.04412 [0<X<120/x: inter-vehicle distance/y: gradient deceleration] can be derived.
[0101] A specific condition may be used to evaluate whether the derived quadratic equation has the characteristic of increasing the deceleration rate as the inter-vehicle distance decreases.
[0102] Based on condition A being satisfied (YES) at step S6, the method proceeds to perform control by reflecting the quadratic equation into the smart regenerative braking system for control at step $7.
[0103] For example, this step involves applying driver's braking characteristic data obtained through clustering to the smart regenerative braking system and implementing the braking (deceleration) starting point and braking (deceleration) intensity (rate) to match the driver's braking pattern.
[0104] That is, by extracting and classifying the driver's braking characteristics as data, the system automatically determines and executes the braking starting point and intensity according to the driver's driving habits, considering conditions such as flat terrain, downhill driving, and the inter-vehicle distance to the vehicle in front.
[0105] For example, the driver's braking starting point and braking intensity extracted based on the values shown in
[0106] Here, x represents the distance, and y represents the gradient deceleration.
[0107] For example, with reference to the graph at the top of
[0108] The numbers are the values of a, b, and c for the driver's pattern presented in
[0109] For example, with reference to the graph at the bottom of
[0110] For example, with reference to
[0111] In this way, the smart regenerative braking is executed by automatically applying the braking starting point and braking intensity in the deceleration segment, reflecting the driver's usual braking characteristics.
[0112] On the contrary, based on condition A being not satisfied (NO) at step S6, the method proceeds to calculate the orthogonal distance from the quadratic equation to remove the deceleration data furthest away at step S8, and determine whether the number of data sets is equal to or greater than a predetermined set at step S9.
[0113] After removing the deceleration data farthest away in orthogonal distance from the quadratic equation, when the number of deceleration data falls below a predetermined set, the procedure goes back to step S1, which involves collecting and inputting the driving data.
[0114] Here, the predetermined set for use in the determination may be five or more. That is based on the number of deceleration data to be removed being less than 5, the procedure goes back to step S1, and then steps S2 to S6 are performed again to extract the driver's braking characteristic data.
[0115] The present disclosure is advantageous in terms of achieving smart regenerative braking control similar to the driver's driving habits by learning the braking patterns preferred by the driver.
[0116] That is, it is possible to perform smart regenerative braking control similar to the user's driving habits by learning the braking patterns preferred by the user based on vehicle control unit (VCU) data. This addresses the issue of braking inconsistency that may arise when using the smart regenerative braking function.
[0117] Furthermore, through the analysis of driving data and the management of personalized driving pattern data in the cloud, individuals can download their personalized data for a driving experience similar to that of a privately owned vehicle even in shared vehicles. This can enhance the driver's driving satisfaction.
[0118] The advantageous effects of the present disclosure are not limited to the aforesaid, and other effects not described herein with can be clearly understood by those skilled in the art from the descriptions below.
[0119] The foregoing descriptions are merely exemplary embodiments of the driving pattern regenerative braking method.
[0120] Therefore, it should be noted that those skilled in the art can readily understand that the present disclosure can be substituted or modified in various forms within the scope of the claims below, without departing from the spirit of the disclosure.