A method for estimating air pollution exposure dose from a single bicycle ride

Abstract

The application discloses a method for estimating air pollution exposure dose of single bicycle riding, comprising the following steps: dividing the riding route of a rider into n road sections, each of which has a length of l; calculating the slope-related speed V of a single road section; then calculating the output power W of the bicycle and the energy consumption E of the rider W = 450 + 9.7067W; calculating the respiratory rate V e ; calculating the exposure dose D e of the road section according to the respiratory rate V seg ; calculating the exposure dose of all road sections in the same way, and the exposure dose of the riding route of the rider is the sum of the exposure doses of all road sections. The application solves the problems in the prior art that the estimation accuracy is low when a rider estimates the air pollution exposure dose during riding by assuming that the rider rides at a fixed speed and the respiratory rate remains unchanged during riding, and the problem that the heart rate of the rider needs to be introduced to correct the respiratory rate, and the exposure dose of a large-scale group cannot be estimated.

Description

Technical Field

[0001] This application belongs to the field of environmental science and technology, specifically relating to a method for estimating air pollution exposure doses during single-cycling riding. Background Technology

[0002] Currently, several methods have been proposed by foreign scholars to assess the dose of a certain air pollutant inhaled by cyclists during cycling routes. These methods estimate the dose of pollutants such as particulate matter, NO2, CO, or SO2 inhaled by cyclists during their rides. However, a common drawback of these methods is that they all assume that cyclists travel at a constant speed and that their breathing rate remains constant during the ride. In reality, both cycling speed and the cyclist's breathing rate vary with terrain changes. Some estimation methods introduce the cyclist's heart rate as a variable to address this issue, estimating the dynamic breathing rate during the ride (because there is a correlation between breathing rate and heart rate), thereby improving the accuracy of exposure dose estimation. However, this method requires direct measurement of each cyclist's real-time heart rate during the ride. Therefore, this method can only be applied to small-scale individual case assessments and is not suitable for large-scale group exposure dose studies. Summary of the Invention

[0003] This application provides a method for estimating air pollution exposure dose during single-cycling riding, which solves the problems of low estimation accuracy in the prior art when estimating air pollution exposure dose for cyclists during riding by assuming that the cyclist rides at a fixed speed and that the breathing rate remains constant during the ride, and the problem that it is impossible to estimate the exposure dose of a large group of people by introducing the cyclist's heart rate to correct the breathing rate.

[0004] To achieve the above objectives, embodiments of the present invention provide a method for estimating air pollution exposure dose during single-cycling riding, comprising the following steps:

[0005] Step 1: Divide the cyclist's route into n segments, each segment having a length of l;

[0006] Step 2: Calculate the gradient-related speed V for a single road segment according to the following formula;

[0007]

[0008]

[0009]

[0010] Among them, V flats represents the constant speed on a flat road section, in km / h; s represents the slope of that road section, in %; slopefactor represents the slope factor; l is in meters.

[0011] Step 3: Calculate the output power of a single vehicle.

[0012] Where η is the mechanical efficiency of the bicycle, M is the total mass of the bicycle and rider, g is the acceleration due to gravity, and C is the acceleration due to gravity. r C is the rolling resistance coefficient of a single vehicle. D Where A is the aerodynamic drag coefficient, ρ is the frontal area of ​​the bicycle and rider, and C is the air density. W Headwind speed;

[0013] Calculate the rider's energy expenditure E W =450 + 9.7067 W;

[0014] Step 4: Calculate the respiratory rate V using the following formula. e The respiratory rate is measured in L / min.

[0015]

[0016] Where ε satisfies N(0, 0.1444); X = 1 when the cyclist is male, and X = 0 when the cyclist is female; Y is the cyclist's age;

[0017] Step 5: Calculate the exposure dose D for this road section. seg , Among them, C X This represents the average concentration of a certain pollutant in this road section.

[0018] Step 6: Calculate the exposure dose for each road segment in the same way. The exposure dose for the cyclist's route is the sum of the exposure doses for all road segments.

[0019] In one possible implementation, V flat The speed is 15 km / h.

[0020] In one possible implementation, the elevation difference between the two ends of the road segment is obtained, and the slope s of the road segment is calculated using the elevation difference and the length l of the road segment.

[0021] In one possible implementation, η is 95%, M is 80 kg, and g is 9.81 m / s². 2 C r C is 0.008. D The value is 1.2, and A is 0.616m. 2 ρ is 1.226 kg / m 3 C W The speed is 0 m / s.

[0022] One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages:

[0023] This invention provides a method for estimating air pollution exposure dose during single-cycling. The method first divides the riding route into segments that vary with terrain, and then establishes a relationship between the cyclist's riding speed and the slope data of individual road segments, thereby deriving the dynamically changing slope-related speed on different road segments. Then, by combining slope-related speed with bicycle attributes, rider attributes, and environmental factors, the bicycle's output power is calculated, thereby determining the rider's energy consumption. This energy consumption reflects the rider's oxygen consumption level, leading to a more accurate breathing rate. The breathing rate then determines the rider's total respiratory volume for that road segment. Finally, combining this with the average concentration of a pollutant on that segment yields the exposure dose. As can be seen, this invention estimates the dynamically changing slope-related speed on different road segments and combines it with the bicycle's output power to obtain accurate rider energy consumption, thus improving the accuracy of breathing rate estimation and consequently, the accuracy of exposure dose estimation. This avoids the problem of low accuracy in existing methods that assume a fixed speed and a constant breathing rate during the ride. Furthermore, this method does not require measuring the rider's real-time heart rate; it estimates the rider's dynamically changing energy consumption based on terrain and road network data, improving the accuracy of existing methods. This makes the method applicable to large-scale group exposure dose estimation, avoiding the problem in existing technologies where real-time heart rate measurement is required for air pollution exposure dose estimation, which prevents the method from being suitable for large-scale group exposure dose estimation. Therefore, the method of the present invention can be used for both individual case evaluation and group case evaluation. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 A flowchart illustrating a method for estimating air pollution exposure dose during single-cycling riding, as provided in an embodiment of the present invention. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] In the description of the embodiments of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the embodiments of the present invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention according to the specific circumstances.

[0028] like Figure 1 As shown in the embodiment of the present invention, the method for estimating air pollution exposure dose during single-cycling riding includes the following steps:

[0029] Step 1: Divide the cyclist's route into n segments, each segment having a length of l;

[0030] Step 2: Calculate the gradient-related speed V for a single road segment according to the following formula;

[0031]

[0032]

[0033]

[0034] Among them, V flat s represents the constant speed on a flat road section, in km / h; s represents the slope of that road section, in %; slopefactor represents the slope factor; l is in meters.

[0035] Step 3: Calculate the output power of a single vehicle.

[0036] Where η is the mechanical efficiency of the bicycle, M is the total mass of the bicycle and rider, g is the acceleration due to gravity, and C is the acceleration due to gravity. r C is the rolling resistance coefficient of a single vehicle. D Where A is the aerodynamic drag coefficient, ρ is the frontal area of ​​the bicycle and rider, and C is the air density. W Headwind speed;

[0037] Calculate the rider's energy expenditure E W =450 + 9.7067 W;

[0038] Step 4: Calculate the respiratory rate V using the following formula. e The respiratory rate is measured in L / min.

[0039]

[0040] Where ε satisfies N(0, 0.1444); X = 1 when the cyclist is male, and X = 0 when the cyclist is female; Y is the cyclist's age;

[0041] Step 5: Calculate the exposure dose D for this road section. seg , Among them, C X This represents the average concentration of a certain pollutant in this road section.

[0042] Step 6: Calculate the exposure dose for each road segment in the same way. The exposure dose for the cyclist's route is the sum of the exposure doses for all road segments.

[0043] It should be noted that C X This represents the average concentration of a certain pollutant in this road section. The pollutant can be NO2, CO, or SO2, etc. The concentration C of the pollutant is... X Air pollutant concentrations can be estimated through modeling, such as using the LUR model to obtain corresponding air pollutant concentration estimates, or through other existing methods. This part is existing technology and will not be elaborated here.

[0044] This invention divides the cyclist's route into n segments. When the terrain slope changes rapidly, n is taken as a larger value, making the length l of each segment shorter, thus allowing for a more accurate exposure dose. When the terrain slope changes slowly, n is taken as a smaller value, meaning the length l of each segment is longer. When environmental factors change rapidly, n is taken as a larger value, thereby reducing the estimation error caused by variables in environmental factors. In this embodiment, l is 20m.

[0045] Generally, cyclists prefer downhill roads because they are less strenuous and allow for faster speeds. However, riding uphill requires more effort, leading to slower speeds and higher energy expenditure, thus requiring more oxygen and resulting in a higher breathing rate. Therefore, through extensive experimentation, the relationship between a cyclist's constant speed on flat roads and the road's gradient was established. As shown in step two, the dynamically changing gradient-dependent speed of the cyclist was derived from the road's gradient, further estimating the breathing rate. The principle of this invention effectively bypasses the need to introduce the cyclist's heart rate variable to address the issue of breathing rate variations with terrain elevation, making the method applicable to group case evaluations.

[0046] g(s,l) is an intermediate calculation function, and both g(s,l) and slopefactor are dimensionless.

[0047] Calculate the rider's energy expenditure E W At that time, E W = 450 + 9.7067W, where E W The units of W and E are not the same, so an equation cannot be directly established using conventional calculation methods. However, the bicycle's output power W and the rider's energy consumption E... W The relationship is directly proportional, therefore linear regression is used to convert E... W The above relationship was established with the numerical part of W, so that the rider's energy consumption E can be obtained more accurately from the bicycle's output power W. W The value.

[0048] This invention first segments the riding route that changes with the terrain, and then establishes a connection between the rider's riding speed and the slope data of a single road segment, thereby deriving the slope-related speed that changes dynamically on different road segments. Then, by combining slope-related speed with bicycle attributes, rider attributes, and environmental factors, the bicycle's output power is calculated, thereby determining the rider's energy consumption. This energy consumption reflects the rider's oxygen consumption level, leading to a more accurate breathing rate. The breathing rate then determines the rider's total respiratory volume for that road segment. Finally, combining this with the average concentration of a pollutant on that segment yields the exposure dose. As can be seen, this invention estimates the dynamically changing slope-related speed on different road segments and combines it with the bicycle's output power to obtain accurate rider energy consumption, thus improving the accuracy of breathing rate estimation and consequently, the accuracy of exposure dose estimation. This avoids the problem of low accuracy in existing methods that assume a fixed speed and a constant breathing rate during the ride. Furthermore, this method does not require measuring the rider's real-time heart rate; it estimates the rider's dynamically changing energy consumption based on terrain and road network data, improving the accuracy of existing methods. This makes the method applicable to large-scale group exposure dose estimation, avoiding the problem in existing technologies where real-time heart rate measurement is required for air pollution exposure dose estimation, which prevents the method from being suitable for large-scale group exposure dose estimation. Therefore, the method of the present invention can be used for both individual case evaluation and group case evaluation.

[0049] Although cyclists may only ride for a short period of time, such as one-twentieth of their day, their high energy expenditure and breathing rate mean that their air pollution exposure dose may account for more than one-tenth of their total daily exposure. Research on air pollution exposure dose becomes even more important when the air pollution index is high, as a higher exposure dose poses a greater health risk to cyclists. The assessment results of this invention can scientifically optimize cyclists' daily active commuting routes, thereby reducing their inhalation of pollutants.

[0050] In this embodiment, V flat The speed is 15 km / h.

[0051] It should be noted that V flat The constant or average speed of a cyclist on a flat road, i.e., when the gradient is zero.

[0052] In this embodiment, the elevation difference between the two ends of the road segment is obtained, and the slope s of the road segment is calculated by using the elevation difference and the length l of the road segment.

[0053] It should be noted that the ratio of the elevation difference to the length l of the road segment is the slope s.

[0054] In this embodiment, η is 95%, M is 80 kg, and g is 9.81 m / s². 2 C r C is 0.008. D The value is 1.2, and A is 0.616m. 2 ρ is 1.226 kg / m 3 C W The speed is 0 m / s.

[0055] It should be noted that the above data are empirical data, and this method can be appropriately modified according to the actual situation in practical application. M is 80kg, of which the cyclist weighs 70kg and the bicycle weighs 10kg.

[0056] In this embodiment, it will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of the equivalents of the claims be included within the present invention.

Claims

1. A method for estimating air pollution exposure dose during single-cycling riding, characterized in that, Includes the following steps: Step 1: Divide the cyclist's route into n segments, each segment having a length of l; Step 2: Calculate the gradient-related speed V for a single road segment according to the following formula; ； ； ； Among them, V flat s represents the constant speed on a flat road section, in km / h; s represents the slope of that road section, in %; slopefactor represents the slope factor; l is in meters. Step 3: Calculate the output power of a single vehicle. ; Where η is the mechanical efficiency of the bicycle, M is the total mass of the bicycle and rider, g is the acceleration due to gravity, and C is the acceleration due to gravity. r C is the rolling resistance coefficient of a single vehicle. D Where A is the aerodynamic drag coefficient, ρ is the frontal area of ​​the bicycle and rider, and C is the air density. W Headwind speed; Calculate the rider's energy expenditure E W =450 + 9.7067 W; Step 4: Calculate the respiratory rate V using the following formula. e The respiratory rate is measured in L / min. in, The condition is satisfied that N(0, 0.1444); X=1 when the cyclist is male, and X=0 when the cyclist is female; Y is the cyclist's age; Step 5: Calculate the exposure dose D for this road section. seg , , where C X This represents the average concentration of a certain pollutant in this road section. Step 6: Calculate the exposure dose for each road segment in the same way. The exposure dose for the cyclist's route is the sum of the exposure doses for all road segments.

2. The method for estimating air pollution exposure dose during single-cycling riding according to claim 1, characterized in that: V flat The speed is 15 km / h.

3. The method for estimating air pollution exposure dose during single-cycling riding according to claim 1, characterized in that: Obtain the elevation difference between the two ends of the road segment, and calculate the slope s of the road segment using the elevation difference and the length l of the road segment.

4. The method for estimating air pollution exposure dose during single-cycling riding according to claim 1, characterized in that: η is 95%, M is 80 kg, and g is 9.81 m / s². 2 C r C is 0.

008. D The value is 1.2, and A is 0.616 m. 2 ρ is 1.226 kg / m 3 C W The speed is 0 m / s.

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