A vehicle driving condition development device and method including road slope

Abstract

The present invention provides a device and method for developing a driving condition of an automobile including a road slope, comprising a data acquisition and processing module, a motion segment library partitioning and weight coefficient determination module, a slope condition and speed condition characteristic parameter extraction module, a condition construction module, and an electronic device. The device and method for developing a driving condition of an automobile including a road slope described in the present invention extract characteristic parameters of the slope condition and the speed condition by actually collecting data such as the vehicle speed and slope during the vehicle's driving process. Representative motion segments that simultaneously meet the characteristic parameters of the slope condition and the speed condition are screened out by using the methods of extreme value test, mean test, and minimum sum of squared deviation test, thereby constructing a driving condition of an automobile including a slope condition. Using this condition as a test condition, an accurate assessment of the fuel consumption and emission levels of vehicles actually traveling in mountainous cities can be achieved through laboratory drum tests.

Description

Technical Field

[0001] The present invention belongs to the field of transportation, and in particular relates to a device and method for developing automobile driving conditions including road slope. Background Art

[0002] Currently, the driving cycles used in my country's vehicle fuel consumption and emissions testing are all speed-time cycles. Because they don't include road slope information, they fail to reflect the impact of slope changes on vehicle fuel consumption and emissions. Slope changes inevitably alter vehicle traction, which in turn leads to changes in the engine's operating point, ultimately causing changes in vehicle fuel consumption and emissions. Therefore, using a simple speed-time driving cycle cannot accurately assess the fuel consumption and emissions characteristics of vehicles in actual mountainous urban environments. Therefore, it is necessary to develop a driving cycle that incorporates slope conditions. Summary of the Invention

[0003] In view of this, the present invention aims to propose a vehicle driving condition development device including road slope to solve the problem that existing vehicle driving conditions cannot accurately evaluate the fuel consumption and emission characteristics of actual driving of vehicles in mountainous cities.

[0004] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0005] A device for developing a vehicle driving condition including road slope includes a data acquisition and processing module, a motion segment library partitioning and weight coefficient determination module, a slope condition and speed condition characteristic parameter extraction module, a condition construction module, and an electronic device. The data acquisition and processing module, the motion segment library partitioning and weight coefficient determination module, the slope condition and speed condition characteristic parameter extraction module, and the condition construction module are sequentially signal-connected. The data acquisition and processing module, the motion segment library partitioning and weight coefficient determination module, the slope condition and speed condition characteristic parameter extraction module, and the condition construction module are all signal-connected to the electronic device.

[0006] The electronic device includes a processor and a memory, wherein the memory is communicatively connected to the processor and is used to store instructions executed by the processor.

[0007] Compared with the prior art, the vehicle driving condition development device including road slope described in the present invention has the following advantages:

[0008] (1) The device for developing automobile driving conditions including road slopes described in the present invention has a simple structure and a reasonable design. Through various modules, the device cuts, cleans and supplements vehicle operation segments, calculates weight coefficients of different speed intervals, extracts characteristic parameters of slope conditions and speed conditions, and screens out typical motion segments of different speed intervals. Finally, the device constructs automobile driving conditions including road slopes, thereby effectively solving the problem that driving conditions cannot accurately evaluate the fuel consumption and emission characteristics of vehicles actually driving in mountainous cities.

[0009] Another objective of the present invention is to develop a driving profile that includes road slope. By collecting data such as vehicle speed and slope during driving, a driving profile that includes a slope condition is constructed, where the slope and speed change synchronously over time. Using this driving profile as a test condition, laboratory drum testing can accurately assess the fuel consumption and emissions of vehicles in actual mountainous urban areas.

[0010] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0011] A method for developing a vehicle driving condition including a road slope comprises the following steps:

[0012] S1. Cut, clean and supplement the vehicle operation segments through the acquisition data processing module;

[0013] S2. Determine the low-speed, medium-speed, and high-speed motion segment library divisions and weight coefficients through a motion segment library division and weight coefficient determination module;

[0014] S3, extracting characteristic parameters of the slope working condition and the speed working condition through a slope working condition and speed working condition characteristic parameter extraction module;

[0015] S4. Construct a vehicle driving condition including a road slope through a condition construction module.

[0016] Furthermore, the vehicle operation segment cutting, cleaning and replenishing in step S1 includes the following steps:

[0017] A1. Determine the vehicle's idle speed and motion status based on the vehicle speed and engine speed data collected using the judgment principle;

[0018] A2. Cut the idle and motion segments using the judgment principle;

[0019] A3. Clean and supplement motion segments based on the requirements of motion segment data missing rate, maximum acceleration and deceleration, and maximum vehicle speed;

[0020] A4. Calculate the total duration of the idle segments and the moving segments respectively, and determine the proportion of time the vehicle is idling and moving.

[0021] The determination principle in step A1 includes the following steps:

[0022] A11. If the vehicle speed is <1 km / h and the engine speed is >0 rpm, the vehicle is considered to be idling. If not, proceed to the next step.

[0023] A12: Determine if the vehicle speed is ≥ 1 km / h and the engine speed is > 0 rpm. If so, determine that the vehicle is in motion. If not, switch to the next vehicle operation segment.

[0024] Furthermore, the cleaning and supplementing of the motion segments in step A3 includes the following steps:

[0025] A31. Determine the maximum acceleration a of the motion segment max Is it greater than 6m / s? 2 Or the minimum deceleration a of the motion segment min Is it less than -6m / s? 2 If yes, then directly remove the motion segment; otherwise, proceed to the next step;

[0026] A32. Determine whether the maximum speed of the motion segment is less than 5 km / h or greater than 120 km / h. If yes, directly discard the motion segment. If no, proceed to the next step.

[0027] A33, determining whether the segment missing rate is greater than or equal to 5%. If yes, directly remove the motion segment; otherwise, proceed to the next step;

[0028] A34. Use the cubic B-spline interpolation method to supplement the missing data including vehicle speed and slope.

[0029] Furthermore, the division of the low-speed, medium-speed, and high-speed motion segment libraries and the determination of weight coefficients in step S2 include the following steps:

[0030] B1. Divide the motion clip library into low-speed, medium-speed, and high-speed;

[0031] B2. Determine the weight coefficients for low-speed, medium-speed, and high-speed intervals;

[0032] The division of the low-speed, medium-speed, and high-speed motion segment libraries in step B1 includes the following steps:

[0033] B11. Determine whether the average speed of the motion segment is greater than 0 km / h and less than or equal to 30 km / h. If yes, it is a low-speed motion segment library. If not, proceed to the next step.

[0034] B12. Determine whether the average speed of the motion segment is greater than 30 km / h and less than or equal to 40 km / h. If yes, it is a medium-speed motion segment library. If not, proceed to the next step.

[0035] B13. Determine whether the average speed of the motion segment is greater than 40 km / h. If yes, select the high-speed motion segment library. If no, switch to the next motion segment.

[0036] Furthermore, the extraction of characteristic parameters of the slope condition and the speed condition in step S3 includes the following steps:

[0037] C1. Extraction of characteristic parameters of slope working conditions;

[0038] C2. Extraction of characteristic parameters of speed conditions.

[0039] Furthermore, the construction of the vehicle driving condition including the road slope in step S4 includes the following steps:

[0040] D1. Screening of typical sports clips;

[0041] D2. Determine the number and duration of motion segments that make up low-speed, medium-speed, and high-speed operating conditions;

[0042] D3. Construct motion segment combinations and working conditions.

[0043] Furthermore, the typical motion segment screening in step D1 includes the following steps:

[0044] D11. Perform extreme value testing to test and screen the motion segments based on their extreme value parameter information;

[0045] D12, perform a mean test, and test and screen the motion segments based on their mean parameter information;

[0046] D13. Use the principle of minimizing the sum of squared deviations to screen out typical low-speed, medium-speed, and high-speed motion clips.

[0047] Furthermore, the determination of the number and duration of the motion segments constituting the low-speed, medium-speed, and high-speed operating conditions in step D2 includes the following steps:

[0048] D21. Calculate the average duration of each motion segment in the low-speed, medium-speed, and high-speed typical motion segment libraries, and determine the number of motion segments that constitute the low-speed, medium-speed, and high-speed working conditions;

[0049] D22. Count the duration of the motion segments in the low, medium, and high speed intervals;

[0050] D23. Calculate the number of motion segments with corresponding durations, sort the durations of the motion segments, and calculate the cumulative frequency distribution of the durations of the motion segments;

[0051] D24. Divide the cumulative distribution into several equal parts based on the number of motion segments determined in different speed intervals. Calculate the duration corresponding to the 50% quantile in each equal part, which is the duration of the motion segment.

[0052] Furthermore, the combination of motion segments and construction of working conditions in step D3 include the following steps:

[0053] D31. Select motion segments from the low-speed, medium-speed, and high-speed motion segment libraries respectively, and randomly combine them according to the number of motion segments to form several low-speed, medium-speed, and high-speed working conditions;

[0054] D32. Select low-speed, medium-speed, and high-speed operating conditions that meet both the slope-slope change rate joint distribution and the speed-acceleration joint distribution;

[0055] D33. Count vehicle travel patterns and determine the average idling time during the vehicle startup phase. This will be used as the idling condition at the start of the operating condition. Based on the number of intervals between movement segments, add idling segments between movement segments and at the end of the movement segments.

[0056] D34. Construct a vehicle driving condition that includes road slope.

[0057] Compared with the prior art, the method for developing a vehicle driving condition including road slope described in the present invention has the following advantages:

[0058] (1) The present invention discloses a method for developing a vehicle driving condition including a road slope. The present invention extracts characteristic parameters of the slope condition and the speed condition by actually collecting data such as the vehicle speed and slope during the vehicle driving process. Representative motion segments that simultaneously meet the characteristic parameters of the slope condition and the speed condition are screened out by using the methods of extreme value test, mean test and minimum sum of square deviation test, thereby constructing a vehicle driving condition including a slope condition, wherein the slope and the vehicle speed change synchronously with time. Using this condition as a test condition, an accurate assessment of the fuel consumption and emission levels of vehicles actually driving in mountainous cities can be achieved through laboratory drum tests. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] The accompanying drawings, which constitute part of the present invention, are provided to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are provided to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0060] Figure 1 A schematic diagram of characteristic parameters of a vehicle driving condition development device and method including road slope according to an embodiment of the present invention;

[0061] Figure 2A schematic diagram of characteristic parameters of a speed condition of a vehicle driving condition development device and method including road slope according to an embodiment of the present invention;

[0062] Figure 3 This is a schematic diagram illustrating an example of determining the duration of a low-speed interval motion segment in a device and method for developing a vehicle driving condition including a road slope according to an embodiment of the present invention;

[0063] Figure 4 This is a schematic diagram of an example of a vehicle driving condition development device and method including a road slope according to an embodiment of the present invention. DETAILED DESCRIPTION

[0064] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0065] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", etc. 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, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0066] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0067] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0068] Glossary:

[0069] Cubic B-spline interpolation: also known as cubic spline interpolation (also known as spline interpolation), is a smooth curve through a series of shape points. Mathematically, it is a process of solving the three bending moment equations to obtain a curve function group.

[0070] In actual calculations, boundary conditions need to be introduced to complete the calculations; general calculation method books do not explain the definition of non-kink boundaries, but numerical calculation software such as Matlab uses non-kink boundary conditions as default boundary conditions.

[0071] The Sum of Squares of Deviations is the sum of the squares of the differences between each term and the mean term. The definition is that if x is a random variable and η = x-Ex, then η is called the deviation of x, which reflects the degree of deviation of x from its mathematical expectation Ex.

[0072] like Figures 1 to 4 As shown, a vehicle driving condition development device including road slope includes a data acquisition processing module, a motion segment library division and weight coefficient determination module, a slope condition and speed condition characteristic parameter extraction module, a condition construction module and an electronic device, wherein the data acquisition processing module, the motion segment library division and weight coefficient determination module, the slope condition and speed condition characteristic parameter extraction module, and the condition construction module are sequentially connected to each other by signals, and the data acquisition processing module, the motion segment library division and weight coefficient determination module, the slope condition and speed condition characteristic parameter extraction module, and the condition construction module are all connected to the electronic device by signals;

[0073] The electronic device includes a processor and a memory, wherein the memory is communicatively connected to the processor and is used to store instructions executed by the processor.

[0074] In this embodiment, a device for developing vehicle driving conditions that include road slope includes the following modules: a data acquisition and processing module for cutting, cleaning, and supplementing vehicle operation segments; a motion segment library division and weight coefficient determination module for dividing the motion segment library into different speed intervals based on the average speed of the motion segments and calculating the weight coefficients for different speed intervals; a slope condition and speed condition characteristic parameter extraction module for extracting slope condition and speed condition characteristic parameters from the low-speed, medium-speed, and high-speed segment libraries; and a condition construction module for screening typical motion segments in different speed intervals and, based on the idling speed and motion condition duration, ultimately constructing a vehicle driving condition that includes road slope.

[0075] An electronic device is provided, comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the aforementioned method. The processor in the electronic device is capable of performing the aforementioned method, thereby providing at least the same advantages as the aforementioned method.

[0076] A medium is provided, on which computer instructions are stored, the computer instructions being used to cause the computer to execute the above method. The computer instructions in the medium can cause the computer to execute the above method, thereby having at least the same advantages as the above method.

[0077] A method for developing a vehicle driving condition including a road slope comprises the following steps:

[0078] S1. Cut, clean and supplement the vehicle operation segments through the acquisition data processing module;

[0079] S2. Determine the low-speed, medium-speed, and high-speed motion segment library divisions and weight coefficients through a motion segment library division and weight coefficient determination module;

[0080] S3, extracting characteristic parameters of the slope working condition and the speed working condition through a slope working condition and speed working condition characteristic parameter extraction module;

[0081] S4. Construct a vehicle driving condition including a road slope through a condition construction module.

[0082] The present invention collects data such as vehicle speed and slope during driving to extract characteristic parameters for both slope and speed conditions. Using extreme value testing, mean testing, and minimum sum of squared deviation tests, representative motion segments that simultaneously meet the characteristic parameters for both slope and speed conditions are selected. This constructs a vehicle driving condition that includes a slope condition, where the slope and speed change synchronously over time. Using this condition as a test condition, laboratory drum testing can accurately assess the fuel consumption and emissions levels of vehicles in actual mountainous urban areas.

[0083] The vehicle operation segment cutting, cleaning and replenishing in step S1 includes the following steps:

[0084] A1. Determine the vehicle's idle speed and motion status based on the vehicle speed and engine speed data collected using the judgment principle;

[0085] A2. Cut the idle and motion segments using the judgment principle;

[0086] A3. Clean and supplement motion segments based on the requirements of motion segment data missing rate, maximum acceleration and deceleration, and maximum vehicle speed;

[0087] A4. Calculate the total duration of the idle segments and the motion segments respectively, and obtain the time ratio of the vehicle idling and motion.

[0088] The determination principle in step A1 includes the following steps:

[0089] A11. If the vehicle speed is <1 km / h and the engine speed is >0 rpm, the vehicle is considered to be idling. If not, proceed to the next step.

[0090] A12: Determine if the vehicle speed is ≥ 1 km / h and the engine speed is > 0 rpm. If so, determine that the vehicle is in motion. If not, switch to the next vehicle operation segment.

[0091] The motion segment cleaning and replenishment in step A3 includes the following steps:

[0092] A31. Determine the maximum acceleration a of the motion segment max Is it greater than 6m / s? 2 Or the minimum deceleration a of the motion segment min Is it less than -6m / s? 2 If yes, then directly remove the motion segment; otherwise, proceed to the next step;

[0093] A32. Determine whether the maximum speed of the motion segment is less than 5 km / h or greater than 120 km / h. If yes, directly discard the motion segment. If no, proceed to the next step.

[0094] A33, determining whether the segment missing rate is greater than or equal to 5%. If yes, directly remove the motion segment; otherwise, proceed to the next step;

[0095] A35. Use the cubic B-spline interpolation method to supplement the missing data including vehicle speed and slope.

[0096] In this embodiment, the vehicle runs segment cutting, cleaning and replenishment

[0097] First, the vehicle's idling and moving state are determined based on the vehicle speed and engine speed collected. If the vehicle speed is <1km / h and the engine speed is >0rpm, the vehicle is determined to be in an idling state; if the vehicle speed is ≥1km / h and the engine speed is >0rpm, the vehicle is determined to be in a moving state.

[0098] Based on the above criteria, idle and motion segments are segmented. An idle segment is specified to be ≤300 seconds long. A motion segment begins with a speed of 0 km / h and ends with a speed of 0 km / h again. The duration of a motion segment is specified to be ≥5 seconds and ≤3600 seconds. Idle and motion segments must appear in pairs.

[0099] The motion segments are cleaned and supplemented based on the requirements of motion segment data missing rate, maximum acceleration and deceleration, and maximum vehicle speed. If the maximum acceleration a of the motion segment max >6m / s 2 Or minimum deceleration a min <-6m / s 2 , the motion segment is directly eliminated; if the maximum speed of the motion segment is <5km / h or >120km / h, the motion segment is directly eliminated; if the motion segment missing rate is ≥5%, the motion segment is directly eliminated; if the missing rate is less than 5%, the missing speed and slope data are supplemented using the cubic B-spline interpolation method. When eliminating a motion segment, the corresponding idle segment must also be eliminated.

[0100] Finally, the total duration of the idle segment and the motion segment is calculated respectively to obtain the time ratio of the vehicle idling and motion.

[0101] The division of the low-speed, medium-speed, and high-speed motion segment libraries and the determination of weight coefficients in step S2 include the following steps:

[0102] B1. Divide the motion clip library into low-speed, medium-speed, and high-speed;

[0103] B2. Determine the weight coefficients for the low-speed, medium-speed, and high-speed intervals.

[0104] The division of the low-speed, medium-speed, and high-speed motion segment libraries in step B1 includes the following steps:

[0105] B11. Determine whether the average speed of the motion segment is greater than 0 km / h and less than or equal to 30 km / h. If yes, it is a low-speed motion segment library. If not, proceed to the next step.

[0106] B12. Determine whether the average speed of the motion segment is greater than 30 km / h and less than or equal to 40 km / h. If yes, it is a medium-speed motion segment library. If not, proceed to the next step.

[0107] B13. Determine whether the average speed of the motion segment is greater than 40 km / h. If yes, select the high-speed motion segment library. If no, switch to the next motion segment.

[0108] In this embodiment, the low-speed, medium-speed, and high-speed motion segment libraries are divided and the weight coefficients are determined.

[0109] (1) Division of low-speed, medium-speed, and high-speed motion clip libraries

[0110] Based on the average speed of the motion clips, the motion clips are divided into low-speed, medium-speed, and high-speed motion clip libraries. Among them, motion clips with an average speed greater than 0 km / h and less than or equal to 30 km / h are classified as low-speed motion clips; motion clips with an average speed greater than 30 km / h and less than or equal to 40 km / h are classified as medium-speed motion clips; motion clips with an average speed greater than 40 km / h are classified as high-speed motion clips.

[0111] (2) Determination of weight coefficients for low-speed, medium-speed, and high-speed intervals

[0112] The sum of the duration of all segments in the low-speed, medium-speed, and high-speed motion segment libraries is calculated to obtain the low-speed, medium-speed, and high-speed weight coefficients. Combined with the vehicle idle and motion time ratios, the duration of idle, low-speed, medium-speed, and high-speed operating conditions is finally obtained.

[0113] The extraction of characteristic parameters of the slope condition and the speed condition in step S3 includes the following steps:

[0114] C1. Extraction of characteristic parameters of slope working conditions;

[0115] C2. Extraction of characteristic parameters of speed conditions.

[0116] In this embodiment, the characteristic parameters of the slope condition and the speed condition are extracted

[0117] (1) Extraction of characteristic parameters of slope conditions

[0118] The slope condition characteristic parameters of each motion segment in the speed motion segment library are extracted, including: uphill time proportion, downhill time proportion, uphill average slope, uphill maximum slope, downhill average slope, downhill maximum slope, uphill average positive rate, downhill average positive rate, uphill average negative rate, downhill average negative rate, uphill maximum positive rate, downhill maximum positive rate, uphill maximum negative rate, downhill maximum negative rate and other 14 characteristic parameters as well as the joint distribution of slope-slope change rate.

[0119] (2) Extraction of characteristic parameters of speed conditions

[0120] The speed condition characteristic parameters of each motion segment in the speed motion segment library are extracted, including six characteristic parameters: average vehicle speed, average positive acceleration, average negative acceleration, maximum vehicle speed, maximum positive acceleration, maximum negative acceleration, and the joint distribution of speed and acceleration.

[0121] The construction of the vehicle driving condition including the road gradient in step S4 includes the following steps:

[0122] D1. Screening of typical sports clips;

[0123] D2. Determine the number and duration of motion segments that make up low-speed, medium-speed, and high-speed operating conditions;

[0124] D3. Construct motion segment combinations and working conditions.

[0125] Typical motion segment screening in step D1 includes the following steps:

[0126] D11. Perform extreme value testing to test and screen the motion segments based on their extreme value parameter information;

[0127] D12, perform a mean test, and test and screen the motion segments based on their mean parameter information;

[0128] D13. Through the joint distribution of slope and slope change rate and the joint distribution of speed and acceleration, the principle of minimizing the sum of squared deviations is used to screen out typical low-speed, medium-speed, and high-speed motion segments.

[0129] Determining the number and duration of motion segments constituting the low-speed, medium-speed, and high-speed operating conditions in step D2 includes the following steps:

[0130] D21. Calculate the average duration of each motion segment in the low-speed, medium-speed, and high-speed typical motion segment libraries, and determine the number of motion segments that constitute the low-speed, medium-speed, and high-speed working conditions based on the duration of the low-speed, medium-speed, and high-speed working conditions;

[0131] D22. Count the duration of the motion segments in the low, medium, and high speed intervals;

[0132] D23. Calculate the number of motion segments with corresponding durations, sort the durations of the motion segments from short to long, and calculate the cumulative frequency distribution of the motion segment durations;

[0133] D24. Divide the cumulative distribution into several equal parts based on the number of motion segments determined in different speed intervals. Calculate the duration corresponding to the 50% quantile in each equal part, which is the duration of the motion segment.

[0134] The combination of motion segments and the construction of working conditions in step D3 include the following steps:

[0135] D31. Select motion segments from the low-speed, medium-speed, and high-speed motion segment libraries respectively, and randomly combine them according to the number of motion segments to form several low-speed, medium-speed, and high-speed working conditions;

[0136] D32. Select low-speed, medium-speed, and high-speed operating conditions that meet both the slope-slope change rate joint distribution and the speed-acceleration joint distribution;

[0137] D33. Count vehicle travel patterns and determine the average idling time during the vehicle startup phase. This will be used as the idling condition at the start of the operating condition. Based on the number of intervals between movement segments, add idling segments between movement segments and at the end of the movement segments.

[0138] D34. Construct a vehicle driving condition that includes road slope.

[0139] In this embodiment, the vehicle driving condition including the road slope is constructed

[0140] (1) Screening of typical motion clips

[0141] Typical motion clips were screened from the low-speed, medium-speed, and high-speed motion clip libraries. First, an extreme value test was performed, testing and screening motion clips based on nine parameters: maximum uphill and downhill slope, maximum positive and negative uphill and downhill speed, maximum vehicle speed, and maximum acceleration and deceleration. Second, a mean value test was performed, testing and screening motion clips based on 11 parameters: uphill and downhill time ratio, average uphill and downhill slope, average positive and negative uphill and downhill speed, average vehicle speed, average acceleration, and average deceleration. Finally, based on the joint distribution of slope and slope change rate and the joint distribution of speed and acceleration, the principle of minimizing the sum of squared deviations was used to finally screen out typical low-speed, medium-speed, and high-speed motion clips.

[0142] (2) Determination of the number and duration of motion segments that make up low-speed, medium-speed, and high-speed operating conditions

[0143] The average duration of each motion segment in the low-speed, medium-speed and high-speed typical motion segment libraries is calculated respectively. According to the duration of the low-speed, medium-speed and high-speed working conditions, the number of motion segments constituting the low-speed, medium-speed and high-speed working conditions is determined.

[0144] To determine the duration of exercise segments, we counted the duration of each segment in the low, medium, and high speed ranges. We then calculated the number of segments with the corresponding durations, sorted the segments from shortest to longest, and calculated the cumulative frequency distribution of the segments' durations. Based on the number of segments identified in each speed range, we divided the cumulative distribution into several equal parts. The duration corresponding to the 50% quantile in each equal part was calculated, which was the duration of the exercise segment.

[0145] (3) Motion segment combination and working condition construction

[0146] According to the duration of the motion segments, motion segments are selected from the low-speed, medium-speed, and high-speed motion segment libraries respectively, and randomly combined according to the number of motion segments, and finally a number of low-speed, medium-speed, and high-speed working conditions are formed.

[0147] Based on the average and minimum deviation principles, we selected low-speed, medium-speed, and high-speed driving conditions that best matched the combined distributions of slope and slope rate of change, as well as the combined distributions of speed and acceleration. We also analyzed vehicle travel patterns and determined the average duration of vehicle idling during the startup phase. This was used as the idle condition at the starting point of the driving condition. Based on the number of intervals between moving segments, we added idle segments between moving segments and at their endpoints, ultimately constructing a driving condition that incorporates road slope.

[0148] Example 1

[0149] The invention method is further described in detail below with reference to the accompanying drawings. The specific steps are as follows:

[0150] Cutting, cleaning and replenishing of vehicle running segments

[0151] First, the vehicle's idling and moving state are determined based on the vehicle speed and engine speed collected. If the vehicle speed is <1km / h and the engine speed is >0rpm, the vehicle is determined to be in an idling state; if the vehicle speed is ≥1km / h and the engine speed is >0rpm, the vehicle is determined to be in a moving state.

[0152] Based on the above criteria, idle and motion segments are segmented. An idle segment is specified to be ≤300 seconds long. A motion segment begins with a speed of 0 km / h and ends with a speed of 0 km / h again. The duration of a motion segment is specified to be ≥5 seconds and ≤3600 seconds. Idle and motion segments must appear in pairs.

[0153] The motion segments are cleaned and supplemented based on the requirements of motion segment data missing rate, maximum acceleration and deceleration, and maximum vehicle speed. If the maximum acceleration a of the motion segment max >6m / s 2 Or minimum deceleration a min <-6m / s 2 , the motion segment is directly eliminated; if the maximum speed of the motion segment is <5km / h or >120km / h, the motion segment is directly eliminated; if the motion segment missing rate is ≥5%, the motion segment is directly eliminated; if the missing rate is less than 5%, the missing speed and slope data are supplemented using the cubic B-spline interpolation method. When eliminating a motion segment, the corresponding idle segment must also be eliminated.

[0154] Finally, the total duration of the idle segments and the moving segments were calculated respectively, and the time proportions of the vehicle idling and moving were obtained, which were 22.11% and 77.89% respectively.

[0155] Division of low-speed, medium-speed and high-speed motion clip libraries and determination of weight coefficients

[0156] Based on the average speed of the motion clips, the motion clips are divided into low-speed, medium-speed, and high-speed motion clip libraries. Among them, motion clips with an average speed greater than 0 km / h and less than or equal to 30 km / h are classified as low-speed motion clips; motion clips with an average speed greater than 30 km / h and less than or equal to 40 km / h are classified as medium-speed motion clips; motion clips with an average speed greater than 40 km / h are classified as high-speed motion clips.

[0157] The sum of the durations of all segments in the low-speed, medium-speed, and high-speed motion segment libraries was calculated to obtain weight coefficients for low-speed, medium-speed, and high-speed conditions. Combined with the vehicle's idle and motion time ratios, the durations of the idle, low-speed, medium-speed, and high-speed operating conditions were ultimately determined. Based on the collected data analysis, the weight coefficients for idle, low-speed, medium-speed, and high-speed conditions were 22.11%, 24.28%, 30.89%, and 22.72%, respectively. Assuming the duration of the low-speed electric drive assembly load condition is 1800 seconds, the weight coefficients were used to calculate the durations of the idle, low-speed, medium-speed, and high-speed conditions to be 398 seconds, 437 seconds, 556 seconds, and 409 seconds, respectively.

[0158] Characteristic parameter extraction of slope conditions and speed conditions

[0159] Extract the slope condition characteristic parameters of each motion segment, including: uphill time ratio P up , downhill time ratio P down , average uphill slope Maximum uphill slope G up，max , average downhill slope Maximum downhill slope G down，max , average positive speed uphill Average positive downhill speed Average negative speed uphill Average negative speed downhill Maximum positive uphill speed G' + up，max , maximum positive downhill speed G' + down，max , maximum negative speed uphill G' - up，max , maximum negative downhill speed G' - down，max 14 characteristic parameters, such as Figure 1 shown.

[0160] When the slope is ≥0.1%, it is defined as uphill; when the slope is ≤-0.1%, it is defined as downhill.

[0161] Uphill time ratio P up is the ratio of the total uphill time in the exercise segment to the total duration of the exercise segment; the downhill time ratio P downIt is the ratio of the total downhill duration in the exercise segment to the total duration of the exercise segment.

[0162] Average uphill slope The arithmetic mean of the slopes of all uphill data points in the motion segment; the average downhill slope The arithmetic mean of the slopes of all downhill data points in the segment.

[0163] Maximum uphill slope G up，max is the 99th percentile of all uphill data points in the motion segment; the maximum downhill slope G down，max is the 99th percentile of all upslope data points in the segment.

[0164] And the slope-slope change rate joint distribution is obtained based on the slope and the slope change rate.

[0165] The slope change rate calculation formula is as follows:

[0166]

[0167] Among them G i ' is the instantaneous slope change rate at the i-th second, where the slope change rate at the zeroth second and the last second is specified to be 0.

[0168] Average positive uphill speed The arithmetic mean of the slope change rate of all data points with a slope ≥ 0.1% and a slope change rate > 0% / s in the exercise segment; the average positive rate of downhill slope The arithmetic mean of the slope change rate of all data points with a slope ≤ -0.1% and a slope change rate > 0% / s in the exercise segment; the average negative rate of uphill slope It is the arithmetic mean of the slope change rate of all data points with a slope ≥ 0.1% and a slope change rate < 0% / s in the exercise segment; the average negative rate of downhill slope It is the arithmetic mean of the slope change rate of all data points in the exercise segment with a slope ≤ -0.1% and a slope change rate < 0% / s.

[0169] Maximum positive uphill speed G' + up，max The 99th percentile of the slope change rate of all data points with a slope ≥ 0.1% and a slope change rate > 0% / s in the motion segment; the maximum positive downhill rate G' + down，max The 99th percentile of the slope change rate of all data points with a slope ≤ -0.1% and a slope change rate > 0% / s in the motion segment; the maximum negative uphill rate G' - up,max The 99th percentile of the slope change rate of all data points with a slope ≥ 0.1% and a slope change rate < 0% / s in the exercise segment; the maximum negative downhill rate G' -down,max The slope change rate is the 99th percentile of all data points with a slope ≤ -0.1% and a slope change rate < 0% / s in the exercise segment.

[0170] Extract the speed condition characteristic parameters of each motion segment, including: average vehicle speed Average positive acceleration Average negative acceleration Maximum speed v max , maximum positive acceleration a + max , maximum negative acceleration a - max There are 6 characteristic parameters, such as Figure 2 shown.

[0171] Average speed It is the arithmetic mean of all instantaneous vehicle speeds in the motion segment.

[0172] The acceleration calculation formula is as follows:

[0173]

[0174] where a i is the acceleration at the i-th second, where the acceleration at the zeroth second and the last second is defined as 0.

[0175] Average speed The arithmetic mean of the acceleration of all data points with acceleration > 0 in the motion segment; the average vehicle speed It is the arithmetic mean of the acceleration of all data points with acceleration < 0 in the motion segment.

[0176] Maximum speed v max is the 99% percentile of all instantaneous vehicle speeds in the motion segment; the maximum positive acceleration a + max The 99th percentile of the acceleration of all acceleration > 0 data points in the motion segment; the maximum negative acceleration a - max is the 99th percentile of the acceleration of all data points with acceleration < 0 in the motion segment.

[0177] And the velocity-acceleration joint distribution is obtained based on the velocity and acceleration.

[0178] Finally, the values ​​of the slope conditions and the characteristic parameters of the speed conditions in the low-speed, medium-speed and high-speed ranges are obtained, among which the values ​​of the characteristic parameters in the low-speed range are shown in Table 1.

[0179] Table 1 Values ​​of characteristic parameters in low-speed range

[0180]

[0181]

[0182] Construction of vehicle driving conditions including road slope

[0183] In the low-speed, medium-speed and high-speed motion clip libraries, the motion clips in each speed range are screened through extreme value test, mean test and minimum sum of square deviation test to obtain low-speed, medium-speed and high-speed typical motion clips.

[0184] Extreme value test: the maximum uphill slope G up，max , Maximum downhill slope G down，max , maximum positive uphill speed G' + up，max , maximum positive downhill speed G' + down，max , maximum negative speed uphill G' - up，max , maximum negative downhill speed G' - down，max And the maximum speed v max , maximum positive acceleration a + max , maximum negative acceleration a - max As the limit conditions, if the characteristic parameters of any slope condition and speed condition in the motion segment exceed the limit, the motion will be directly eliminated.

[0185] Mean test: the proportion of time uphill P up , downhill time ratio P down , average uphill slope Average downhill slope Average positive uphill speed Average positive downhill speed Average negative speed uphill Average negative speed downhill Average speed Average positive acceleration Average negative acceleration As the fluctuation range of the characteristic parameter, the motion segments that simultaneously meet the fluctuation range of the mean values ​​of all the above characteristic parameters are screened out again.

[0186] Minimum sum of squared deviations test: Based on the joint distribution of slope and slope change rate and the joint distribution of speed and acceleration, the principle of minimum sum of squared deviations is used to ultimately screen out typical low-speed, medium-speed, and high-speed motion segments.

[0187] The average duration of the selected low-speed, medium-speed, and high-speed typical motion clips was 62.5 seconds, 184.3 seconds, and 410.3 seconds, respectively. Since the durations of low-speed, medium-speed, and high-speed motion clips were 437 seconds, 556 seconds, and 409 seconds, respectively, the number of low-speed, medium-speed, and high-speed motion clips was 6.99, 3.02, and 1.00, respectively, which were rounded to 7, 3, and 1, respectively.

[0188] Then, the duration of the motion segments in the low-speed, medium-speed, and high-speed intervals was counted, and the number of motion segments with the corresponding duration was calculated. The duration of the motion segments was sorted from short to long, and the cumulative frequency distribution of the motion segment duration was calculated. According to the number of motion segments determined in different speed intervals, the cumulative distribution was divided into several equal parts, and the duration corresponding to the 50% quantile in each equal part was calculated, which is the duration of the motion segment. Taking the low-speed interval as an example, the cumulative distribution of its segment duration is as follows: Figure 3 As shown, the durations of the seven segments are 6s, 8s, 12s, 20s, 30s, 47s, and 85s respectively.

[0189] According to the duration of the motion segments, motion segments are selected from the low-speed, medium-speed, and high-speed motion segment libraries respectively, and according to the number of motion segments, they are randomly combined to finally form a number of low-speed, medium-speed, and high-speed working conditions. Then, according to the average and minimum principle of deviation, the low-speed, medium-speed, and high-speed working conditions that best conform to the joint distribution of slope-slope change rate and the joint distribution of speed-acceleration are selected. The vehicle travel patterns are counted to determine the average idling time of the vehicle during the startup phase, which is used as the idling working condition at the starting point of the working condition. Then, according to the number of intervals between motion segments, idling segments are added between the motion segments and at the end point respectively. According to the vehicle travel patterns, the average idling time of the vehicle during the startup phase is determined to be 35s, and there are a total of 10 intervals in the motion segments. Considering the end point of the working condition, there are a total of 11 intervals. According to the determined idling working condition duration of 398s, excluding the idling time at the starting point, it is 363s. The idling time of each interval and the end point should be 33s, and the slope is 0 under the idling working condition. Finally, the construction of the automobile driving working condition including the road slope is completed, such as Figure 4 shown.

[0190] In summary, the present invention extracts characteristic parameters of slope and speed conditions by collecting data such as vehicle speed and slope during driving. By using extreme value testing, mean testing, and minimum sum of squared deviation testing, representative motion segments that simultaneously meet the characteristic parameters of both slope and speed conditions are selected, thereby constructing a vehicle driving condition that includes a slope condition, in which the slope and speed change synchronously over time. Using this condition as a test condition, laboratory drum testing can accurately assess the fuel consumption and emission levels of vehicles actually traveling in mountainous cities.

[0191] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for developing a vehicle driving condition including road slope, implemented by a device for developing a vehicle driving condition including road slope, characterized in that: The vehicle driving condition development device including road slope includes a data acquisition processing module, a motion segment library division and weight coefficient determination module, a slope condition and speed condition characteristic parameter extraction module, a condition construction module and an electronic device, wherein the data acquisition processing module, the motion segment library division and weight coefficient determination module, the slope condition and speed condition characteristic parameter extraction module, and the condition construction module are sequentially connected to each other by signals, and the data acquisition processing module, the motion segment library division and weight coefficient determination module, the slope condition and speed condition characteristic parameter extraction module, and the condition construction module are all connected to the electronic device by signals; The electronic device includes a processor and a memory, the memory being communicatively connected to the processor, and the memory being configured to store instructions executed by the processor; The development methodology includes the following steps: S1. Cut, clean and supplement the vehicle operation segments through the acquisition data processing module; S2. Determine the low-speed, medium-speed, and high-speed motion segment library divisions and weight coefficients through a motion segment library division and weight coefficient determination module; The division of the low-speed, medium-speed, and high-speed motion segment libraries and the determination of weight coefficients in step S2 include the following steps: B1. Divide the motion clip library into low-speed, medium-speed, and high-speed; B2. Determine the weight coefficients for low-speed, medium-speed, and high-speed intervals; Determination of weight coefficients for low speed, medium speed and high speed intervals: The sum of the duration of all segments in the low-speed, medium-speed, and high-speed motion segment libraries is calculated to obtain the low-speed, medium-speed, and high-speed weight coefficients. Combined with the vehicle's idle and motion time ratios, the duration of the idle, low-speed, medium-speed, and high-speed operating conditions is finally obtained. S3, extracting characteristic parameters of the slope working condition and the speed working condition through a slope working condition and speed working condition characteristic parameter extraction module; The extraction of characteristic parameters of the slope condition and the speed condition in step S3 includes the following steps: C1. Extraction of characteristic parameters of slope working conditions; C2. Extraction of characteristic parameters of speed conditions; Slope working condition characteristic parameter extraction: Extract the slope condition characteristic parameters of each motion segment in the speed motion segment library, including: uphill time ratio, downhill time ratio, uphill average slope, uphill maximum slope, downhill average slope, downhill maximum slope, uphill average positive rate, downhill average positive rate, uphill average negative rate, downhill average negative rate, uphill maximum positive rate, downhill maximum positive rate, uphill maximum negative rate, downhill maximum negative rate 14 characteristic parameters and the joint distribution of slope-slope change rate; Speed ​​condition characteristic parameter extraction: Extract the speed condition characteristic parameters of each motion segment in each speed motion segment library, including six characteristic parameters: average vehicle speed, average positive acceleration, average negative acceleration, maximum vehicle speed, maximum positive acceleration, maximum negative acceleration, and the joint distribution of speed and acceleration; S4. Constructing a vehicle driving condition including a road slope through a condition construction module; The construction of the vehicle driving condition including the road gradient in step S4 includes the following steps: D1. Screening of typical sports clips; D2. Determine the number and duration of motion segments that make up low-speed, medium-speed, and high-speed operating conditions; D3, construct motion segment combinations and working conditions; Typical motion segment screening in step D1 includes the following steps: D11. Perform extreme value testing to test and screen the motion segments based on their extreme value parameter information; D12, perform a mean test, and test and screen the motion segments based on their mean parameter information; D13. Use the principle of minimizing the sum of squared deviations to select typical low-speed, medium-speed, and high-speed motion segments; Determining the number and duration of motion segments constituting the low-speed, medium-speed, and high-speed operating conditions in step D2 includes the following steps: D21. Calculate the average duration of each motion segment in the low-speed, medium-speed, and high-speed typical motion segment libraries, and determine the number of motion segments that constitute the low-speed, medium-speed, and high-speed working conditions; D22. Count the duration of the motion segments in the low, medium, and high speed intervals; D23. Calculate the number of motion segments with corresponding durations, sort the durations of the motion segments, and calculate the cumulative frequency distribution of the durations of the motion segments; D24. Divide the cumulative distribution into several equal parts based on the number of motion segments determined in different speed intervals. Calculate the duration corresponding to the 50% quantile in each equal part, which is the duration of the motion segment. The combination of motion segments and the construction of working conditions in step D3 include the following steps: D31. Select motion segments from the low-speed, medium-speed, and high-speed motion segment libraries respectively, and randomly combine them according to the number of motion segments to form several low-speed, medium-speed, and high-speed working conditions; D32. Select low-speed, medium-speed, and high-speed operating conditions that meet both the slope-slope change rate joint distribution and the speed-acceleration joint distribution; D33. Count vehicle travel patterns and determine the average idling time during the vehicle startup phase. This will be used as the idling condition at the start of the operating condition. Based on the number of intervals between movement segments, add idling segments between movement segments and at the end of the movement segments. D34. Construct a vehicle driving condition that includes road slope.

2. The method for developing a vehicle driving condition including road slope according to claim 1, characterized in that: The vehicle operation segment cutting, cleaning and replenishing in step S1 includes the following steps: A1. Determine the vehicle's idle speed and motion status based on the vehicle speed and engine speed data collected using the judgment principle; A2. Cut the idle and motion segments using the judgment principle; A3. Clean and supplement motion segments based on the requirements of motion segment data missing rate, maximum acceleration and deceleration, and maximum vehicle speed; A4. Calculate the total duration of the idle segments and the moving segments respectively, and determine the proportion of time the vehicle is idling and moving. The determination principle in step A1 includes the following steps: A11. If the vehicle speed is <1 km / h and the engine speed is >0 rpm, the vehicle is considered to be idling. If not, proceed to the next step. A12: Determine if the vehicle speed is ≥ 1 km / h and the engine speed is > 0 rpm. If so, determine that the vehicle is in motion. If not, switch to the next vehicle operation segment.

3. The method for developing a vehicle driving condition including road slope according to claim 2, characterized in that: The motion segment cleaning and replenishment in step A3 includes the following steps: A31. Determine the maximum acceleration a of the motion segment max Is it greater than 6m / s? 2 Or the minimum deceleration a of the motion segment min Is it less than -6m / s? 2 If yes, then directly remove the motion segment; otherwise, proceed to the next step; A32. Determine whether the maximum speed of the motion segment is less than 5 km / h or greater than 120 km / h. If yes, directly discard the motion segment. If no, proceed to the next step. A33, determining whether the segment missing rate is greater than or equal to 5%. If yes, directly remove the motion segment; otherwise, proceed to the next step; A34. Use the cubic B-spline interpolation method to supplement the missing data including vehicle speed and slope.

4. The method for developing a vehicle driving condition including road slope according to claim 1, characterized in that: The division of the low-speed, medium-speed, and high-speed motion segment libraries in step B1 includes the following steps: B11. Determine whether the average speed of the motion segment is greater than 0 km / h and less than or equal to 30 km / h. If yes, it is a low-speed motion segment library. If not, proceed to the next step. B12. Determine whether the average speed of the motion segment is greater than 30 km / h and less than or equal to 40 km / h. If yes, it is a medium-speed motion segment library. If not, proceed to the next step. B13. Determine whether the average speed of the motion segment is greater than 40 km / h. If yes, select the high-speed motion segment library. If no, switch to the next motion segment.

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