Slope design method and system for long uphill section of tunnel based on TruckSim

Abstract

The application discloses a kind of based on TruckSim's tunnel long uphill section's slope design method and system, including step one: determining target vehicle, obtaining the parameter information of each target vehicle and tunnel to be designed;Step two. Based on TruckSim simulation each target vehicle determined in the step two Real state analysis various resistance values, step three: the balanced relationship model of car type is obtained by the resistance analyzed in the step two, and the balanced slope length is calculated;Step four: according to the balanced slope length, the longitudinal slope of the long uphill of the tunnel to be designed is divided into several sections, three kinds of slope design are used to design different types of situations, the parameter information of the tunnel to be designed is combined with various types of situations to calculate the carbon emission, so as to determine the optimal scheme of the slope design of the tunnel long uphill.The application is dominated by the carbon emission angle Tunnel longitudinal slope design, which is convenient for tunnel design scheme comparison and selection.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of tunnel long uphill section longitudinal slope design method, and particularly relates to a tunnel long uphill section slope design method and system based on TruckSim. BACKGROUND

[0002] The green low-carbon design concept occupies a pivotal position in the current era, and its importance is self-evident. The tunnel long uphill section longitudinal slope design method based on carbon emission indicators not only provides a forward-looking guiding idea for the tunnel design field, but also has urgent practical needs and far-reaching significance.

[0003] Studies have shown that the uphill section of the longitudinal slope is the main section of the vehicle carbon emission, and the carbon emission can be reduced by controlling the alignment of the longitudinal slope section. Some scholars have studied the influence of single longitudinal section alignment parameters such as slope on carbon emission.

[0004] For example, Kanok Boriboonsomsin conducted a real vehicle experiment, which has the disadvantages of being limited by actual conditions and only considering a small car. Emrah Demir also studied the influence of slope on exhaust emission, but the number of road samples in the real vehicle experiment is very limited, and all are based on a single longitudinal slope, not a continuously changing longitudinal slope.

[0005] Later, some scholars conducted research on continuous longitudinal slope sections. Jinliang Xu studied the carbon emission of a small car traveling back and forth on a continuous longitudinal slope section at a constant speed through a real vehicle experiment, but still cannot solve the two inherent shortcomings of the real vehicle experiment, one is that the vehicle type is limited to a small car, and the other is that the parameters can only be collected based on the existing road, which does not have the function of simulation and foresight.

[0006] Another important problem is that the road surface materials of tunnels and ordinary roads are different. Typically, if a tunnel is paved with asphalt, the toxic smoke produced by combustion in a closed space is much more harmful than in an open space, so a large amount of flame retardant additive needs to be added, or a cement pavement is selected. Therefore, the friction coefficients of tunnel pavements and ordinary roads are different, which will seriously affect the calculation of vehicle carbon emission. The existing research does not take this factor into account, so there is a certain error in the existing research on the longitudinal slope of the long tunnel uphill, which is not convenient for providing effective reference for subsequent long tunnel slope design. SUMMARY

[0007] In view of the shortcomings of the prior art, the present application aims to provide a tunnel long uphill section slope design method and system based on TruckSim, which analyzes the comprehensive influence of longitudinal section alignment combination and vehicle driving state on carbon emission, dominates the tunnel longitudinal slope design from the perspective of carbon emission, and is convenient for design scheme comparison and selection.

[0008] To achieve one of the above purposes, the technical scheme adopted by the present application is as follows:

[0009] A slope design method for a long uphill section of a tunnel based on TruckSim, characterized in that it comprises the following steps:

[0010] Step one: determine target vehicles and obtain parameter information of each target vehicle and the tunnel to be designed;

[0011] Step two: simulate the true state of each target vehicle determined in step one based on TruckSim to analyze various resistance values, specifically including:

[0012] S201: establish a vehicle model and a driving model based on Trucksim according to the parameter information of the target vehicle;

[0013] S202: analyze and calculate the resistance values of each target vehicle based on the vehicle model and the driving model;

[0014] Step three: derive a balance relationship model of the vehicle type based on the resistance analyzed in S2 and calculate the balance slope length; specifically including:

[0015] S301: according to the combined action of traction and resistance when driving on a longitudinal slope, the vehicle reaches a balanced state under the action of the resultant force, and a quadratic function of the power factor D and the speed V is derived, D = PV2 + QV + W, where P, Q, and W are constant coefficients;

[0016] S302: divide the displacement of the vehicle climbing the slope into multiple units, each unit can be regarded as uniform variable speed motion, and use the relevant theory of kinematics to solve the balance slope length S corresponding to the balance speed;

[0017] Step four: divide the longitudinal slope of the long uphill section of the tunnel to be designed into several sections according to the balance slope length, use the climbing slope, the gentle slope, and the flat slope to design different types of situations, combine the parameter information of the tunnel to be designed with various types of situations to calculate the carbon emissions, and thus determine the optimal solution for the slope design of the long uphill section of the tunnel.

[0018] Further, S201 also includes establishing a road scene model.

[0019] Further, step four is also included, which uses carbon emission mechanical parameters to verify the slope design scheme.

[0020] Further, S202: according to the vehicle model and the driving model, the resistance values of each target vehicle are analyzed and calculated, specifically including: the resistance of the target vehicle on the longitudinal slope includes rolling resistance Ff, air resistance Fw, slope resistance Fi, and acceleration resistance Fj.

[0021] The rolling resistance Ff, i.e. the vehicle rolling resistance, is mainly caused by the deformation of the tire and the road surface when the wheel rolls. In addition, there is friction between the tire and the road surface and the wheel shell bearing, and these deformations and frictions generated when the wheel rolls consume a certain internal force of the engine, forming the rolling resistance;

[0022] The air resistance Fw is proportional to the shape, projected area and square of the speed of the vehicle. During the vehicle driving process, the airflow makes a flow around the vehicle, resulting in a pressure difference between the front and rear of the vehicle and the friction between the air and the surface of the vehicle, plus the airflow disturbance caused by indoor ventilation and cooling of the engine, forming the resistance;

[0023] The slope resistance Fi is the resistance formed by the component of the total gravity of the car along the road surface when the car climbs uphill;

[0024] The acceleration resistance Fj is the inertia force that needs to be overcome when the car accelerates on an uphill or adjusts the speed to maintain the existing speed.

[0025] Further, the 301: according to the combined action of the traction force and the resistance when driving on the longitudinal slope, the vehicle reaches a balanced state under the action of the resultant force, and a quadratic function of the power factor D and the speed V is obtained, D = PV2 + QV + W, specifically comprising:

[0026] The sum of the various resistances Ft received by the vehicle is

[0027] Ft = Fw + Ff + Fi + Fj

[0028] The above formula is transformed to obtain

[0029]

[0030] In order to eliminate the difference in vehicle weight, divide both ends of the above formula by the total weight of the vehicle G:

[0031]

[0032] Let the left end of the above formula be D, then

[0033]

[0034] D is called the power factor, which represents the performance of the target vehicle on the sea level elevation to overcome the road resistance and acceleration resistance per unit vehicle weight. The larger this value is, the greater the acceleration, climbing and road resistance overcoming ability of the car is. It is the main index of the traction performance of the vehicle. When the traction force is equal to the resistance, the balance state is reached, and the above formula is substituted to obtain:

[0035]

[0036] Wherein U represents the load rate, M represents the engine crankshaft torque (N m), Y represents the total gear ratio, Y = i0 *ik, i0 is the main transmission ratio, ik is the transmission ratio, η T represents the mechanical efficiency of the transmission system, C d represents the air resistance coefficient, r represents the wheel radius (m), and the above formula can be transformed as follows:

[0037]

[0038] Wherein Mmax represents the maximum torque (N m);

[0039] MN represents the torque corresponding to the maximum power;

[0040] nN represents the speed corresponding to the maximum power (r / min);

[0041] nM represents the speed corresponding to the maximum torque (r / min);

[0042] By merging and simplifying the complex coefficient, the power factor D can be represented as a quadratic function of the speed V, that is:

[0043] D = PV2 + QV +W

[0044]

[0045]

[0046]

[0047] Wherein P, Q and W are constant coefficients;

[0048] Since the power factor D is calculated and drawn according to the standard value at sea level and under the full load condition of the vehicle, if the road is not at sea level and the vehicle load does not reach the full load state, the difference in altitude will also cause deviation in the performance output of the vehicle, so a correction coefficient λ is introduced to correct the power factor;

[0049]

[0050]

[0051] Wherein: is the altitude coefficient, generally taken as = (1-2.26 x 10 -5 H) 5.3 H is the altitude (m),

[0052] G is the total weight of the vehicle (N), G' is the total weight of the vehicle when loaded (N).

[0053] Further, S302: the displacement of the vehicle climbing the slope is divided into multiple units, each unit can be regarded as uniform variable speed motion, and the balance slope length S corresponding to the balance speed is solved by using the related theory of kinematics; specifically including:

[0054] S3021: solving the balance speed

[0055] When the vehicle drives on a long uphill slope, the driving speed has a small fluctuation, but after a certain degree, the speed is in a stable state. Each uphill slope has a balance speed when the slope length increases to a certain value, so the minimum slope length corresponding to the stable speed can be solved.

[0056] Firstly, according to the principle of vehicle dynamics, the acceleration ɑ of the vehicle under different gears is calculated by the following formula:

[0057]

[0058] In the formula: Ψ represents the road resistance coefficient ; Inertia force coefficient δ = 1+ δ1 + δ2i ;

[0059] Then, the balance speed of the next unit is calculated by the acceleration, and the final speed v2 of the previous unit is taken as the initial speed of the next unit. According to the basic theorem of kinematics v2 = v0 2 + 2aS, in the formula, the initial speed of the previous unit is v0, and the final speed v2 of the previous unit;

[0060] Finally, according to D-Ψ = Pv2 + Qv+W -Ψ = 0, we get:

[0061]

[0062] In the formula: Vp——Balance speed, km / h, Ψ represents the road resistance coefficient. Assuming that the vehicle drives on a good asphalt or concrete road surface, the rolling resistance coefficient f = 0.01, and the altitude load correction coefficient λ = 0.90;

[0063] S3021: balance slope length

[0064] The displacement of the vehicle climbing the slope is divided into multiple units, and after considering the influence of acceleration, each unit can be regarded as uniform variable speed motion. By using the related theory of kinematics, the balance slope length S corresponding to the balance speed can be solved.

[0065] Substitute D = Pv2 + Qv + W into

[0066]

[0067] Move terms to the above equation, and integrate both sides to get:

[0068]

[0069] Let B = W - Then the above equation is:

[0070]

[0071] When Q2 - 4PB≥0 in the equation, the integral result is:

[0072]

[0073] When Q2 - 4PB<0 in the equation, the integral result is:

[0074]

[0075] The above equation is the balance relationship model of the main truck type, and C in the two equations is the integral constant.

[0076] Further, the step four specifically includes:

[0077] According to the height of the long uphill section of the tunnel to be designed, a plurality of slope types are combined by using three different slopes, according to the driving speed requirement in the tunnel, the climbing speed and displacement relationship of the main truck type is obtained by simulation and calculation, the carbon emission of various slope combinations is calculated, and the slope design method of the long uphill section of the tunnel is determined according to the obtained various carbon emissions;

[0078] According to the linear regression formula obtained by fitting,

[0079] The speed component carbon emission formula is: Ecs1= -0.01Vp 2 - Vp + 708

[0080] The slope correlation carbon emission formula is: Ecs2= 0.0004i 2 - 0.4342i + 133.74

[0081] The slope length carbon emission formula is: Ecs3= 0.000002S 3 - 0.0078S 2 + 10.184S - 3107.1

[0082] The total carbon emission formula is Ecs=Ecs1+Ecs2+Ecs3,

[0083] Wherein, Ecs is the carbon emission prediction value, unit is gCo2e / veh, veh is the traffic capacity unit vehicle, i is the road longitudinal slope, S is the equilibrium slope length, Vp is the equilibrium speed;

[0084] The slope type combination with the minimum carbon emission is selected as the optimal slope design scheme.

[0085] In order to achieve the above-mentioned second purpose, the technical scheme adopted by the present application is as follows:

[0086] A system based on the above-mentioned TruckSim-based tunnel long uphill slope design method, comprising a data acquisition module, a data modeling module and an analysis processing module,

[0087] The data acquisition module is used to determine target vehicles and obtain parameter information of each target vehicle.

[0088] The data modeling module is used to simulate the real state of each target vehicle determined in step one based on TruckSim, establish a vehicle model and a driving model based on Trucksim according to the parameter information of the target vehicle, and analyze and calculate the resistance value of each target vehicle according to the vehicle model and the driving model.

[0089] The analysis processing module is used to derive the equilibrium relationship model of the vehicle type through the analyzed resistance, calculate the equilibrium slope length, derive the quadratic function of the power factor D and the speed V according to the combined action of the traction force and the resistance when driving on the longitudinal slope, and the vehicle reaches the equilibrium state under the action of the resultant force, D=PV2+QV+W; divide the displacement of the vehicle climbing into small enough units, each unit can be regarded as uniform variable speed motion, and the equilibrium slope length S corresponding to the equilibrium speed is solved by using the related theory of kinematics; according to the equilibrium slope length, the longitudinal slope of the tunnel long uphill to be designed is divided into several segments, the climbing slope, the gentle slope and the flat slope are designed in different types, the parameter information of the tunnel to be designed is combined with various types to calculate the carbon emission, and thus the optimal slope design scheme of the tunnel long uphill is determined.

[0090] The significant effect of the present application is:

[0091] Based on Trucksim software, simulation of various vehicles and various slopes is completed, the comprehensive influence of longitudinal section line combination and vehicle driving state on carbon emission is analyzed, and the longitudinal slope design is dominated from the perspective of carbon emission to facilitate the comparison and selection of design schemes. Meanwhile, the differences between tunnel materials and traditional road materials are fully considered, the different friction coefficients of road surface are designed, the resistance of vehicle is correspondingly different, the analysis results obtained by considering the road surface design are more accurate, the accuracy of data is improved, which is closer to the true value, providing effective support for the design data of long slope in tunnel, promoting the green traffic construction and the sustainable development of the whole society. BRIEF DESCRIPTION OF DRAWINGS

[0092] Figure 1 is a flowchart of the embodiment 1;

[0093] Figure 2 is a force diagram of a truck on a longitudinal slope in the embodiment 1;

[0094] Figure 3 is a driving force-traveling resistance balance diagram of an automobile with a 5-gear transmission in the embodiment 1;

[0095] Figure 4 is a power characteristic diagram in the embodiment 1;

[0096] Figure 5 is a speed fluctuation curve diagram of an automobile in the embodiment 1;

[0097] Figure 6 is a diagram showing that a tunnel is divided into 11 sections in the embodiment 1;

[0098] Figure 7 is Figure 6 a diagram showing the height difference of a tunnel;

[0099] Figure 8 is Figure 6 a diagram showing one of the design schemes of a tunnel;

[0100] Figure 9 is a carbon emission column chart of three tunnel design schemes with a design speed of 80 km / h in the embodiment 1;

[0101] Figure 10 is a carbon emission column chart of three tunnel design schemes with a design speed of 60 km / h in the embodiment 1;

[0102] Figure 11 is a carbon emission column chart of three tunnel design schemes with a design speed of 40 km / h in the embodiment 1. DETAILED DESCRIPTION

[0103] The specific embodiments of the present application and working principles are further described in detail below with reference to the accompanying drawings.

[0104] Referring to Figures 1 to 11 The TruckSim-based slope design method for a long uphill section of a tunnel is shown in the following steps:

[0105] Step one: determine the target vehicle and obtain the parameter information of each target vehicle and the tunnel to be designed;

[0106] The target vehicle can be a car in traditional research, or a bus or a truck. The approximate carbon emission values of various vehicle types given in existing related literature are only approximate or equal values, which are not sufficient to guide the design of a long uphill section of a tunnel. Therefore, a TruckSim-based calculation method for improving the carbon emission of the target vehicle is used to improve the accuracy of the carbon emission value.

[0107] The carbon emission of a vehicle on a long uphill section is related to various factors such as tire stress, vehicle power, and driving habits. Since the vehicle rarely undergoes significant acceleration or deceleration when driving on a long uphill section, the resistance it receives tends to be stable, which can be regarded as a balanced speed. Therefore, a method is proposed to inversely calculate the carbon emission based on the balanced speed. The parameter information of the target vehicle includes the total weight of the vehicle when fully loaded, the load weight, the fuel type, the tire performance, the vehicle power, the engine efficiency, the vehicle transmission system type, the driver behavior pattern, the vehicle service life and maintenance condition. The parameter information of the tunnel to be designed includes the tunnel pavement material type, the road resistance coefficient, the altitude, the height difference between the starting and ending points of the tunnel, the tunnel speed limit, the vehicle driving environment, the traffic flow, the traffic stability, and the weather conditions.

[0108] For example, a Dongfeng truck EQ1228V19D2 with a total mass of 22.00 t, a rated load of 12.00 t, a total mass of 8.30 t, a power-to-mass ratio of 8.05 kW / t, a Dongfeng bus EQ6750H3G1 with a total mass of 7.85 t and a total mass of 5.28 t, a Dongfeng car DFM6473M5F6BEV with a total mass of 2.13 t and a total mass of 1.72 t, and other different vehicle types can be selected as target vehicles. The parameters of the tunnel to be designed are two-way two-lane, with a lane width of 3.75 m, an asphalt concrete pavement, a pavement adhesion coefficient of 0.7, and a 1.5% two-way road camber transverse slope for straight sections.

[0109] Step two. Based on TruckSim simulation, analyze various resistance values based on the real state of each target vehicle determined in step one, specifically including:

[0110] S201: Establish a vehicle model and a driving model based on Trucksim according to the parameter information of the target vehicle;

[0111] (1) Establishing vehicle model

[0112] The body modeling is mainly to parameterize the description of the sprung mass and load of the vehicle by using Trucksim. To describe the body, the body mass center coordinate system is first defined, the origin of which is the body mass center, the forward direction of the vehicle is the X axis, the forward direction is positive, the plumb (vertical) direction is the Z axis, the upward direction is positive, and the Y axis is determined by the right-hand screw principle, which is consistent with the body mass center coordinate system defined in Trucksim software. In this embodiment, the body mass center coordinate system of the project is constructed by the leading vehicle type Dongfeng truck EQ1228V19D2, and the road surface material, tunnel speed limit, tunnel long and large slope requirements are input.

[0113] Trucksim controls the load of the vehicle by inputting the sprung mass of the target vehicle. In automotive engineering, the body is the largest "rigid body" in the vehicle system, and the motion of the body can be regarded as the motion of the vehicle. Strictly speaking, the body is the sprung mass of the vehicle, that is, the part above the suspension. However, in addition to the vibration and longitudinal and lateral roll of the body, the body mass can include the engine and chassis mass in the planar motion of the vehicle, such as longitudinal movement, lateral movement and steering, because the engine and chassis have the same motion as the body. In this case, the body mass is the total mass of the vehicle, and the study of the uphill problem of the vehicle can be regarded as the planar motion of the vehicle in the xoz plane, so the sprung mass of the leading vehicle type can be set as the total mass of the vehicle. In this embodiment, the total mass of the vehicle is the total weight of the vehicle when it is fully loaded, and the total mass of the Dongfeng truck EQ1228V19D2 is 22000kg.

[0114] (2) Determine the driver model

[0115] According to relevant investigations, the driver usually takes the measures of adding and reducing gears by relying on the judgment of the vehicle speed and the sound of the engine working, which is adjusted to the ideal state in the model. The model is an automatic gear shifting method, that is, it is assumed that when the power factor of the vehicle reaches the maximum value of the gear, the driver takes the gear shifting measures decisively, and the gear shifting operation time is ignored. The "throttle" control in the driver model is set to automatic, that is, it is assumed that the driver of the leading vehicle type truck always steps on the throttle to the ideal state during the climbing process.

[0116] Possibly, the S201: based on Trucksim to establish a vehicle model and driving model also includes establishing a road scene model, constructing a road scene model according to the tunnel parameters to be designed, and further improving the accuracy of the measurement data. The construction of the road scene model mainly considers three factors: road geometric characteristics, road adhesion coefficient and road superhigh. The experimental section adopts a straight line, the total length of the road is 5.5km, two-way two lanes, the lane width is set to 3.75m, the asphalt concrete pavement, the road adhesion coefficient is 0.7, according to the relevant specifications and references, the road considers various factors such as sign setting, construction difficulty, driver's sight distance, existing vehicle conditions, existing pavement material performance, specification requirements, etc., especially considering the balance of the balance slope length.

[0117] S202: analyzing and calculating the resistance value of each target vehicle according to the vehicle model and driving model; specifically including: the resistance of the target vehicle on the longitudinal slope is decomposed into rolling resistance Ff, air resistance Fw, slope resistance Fi and acceleration resistance Fj,

[0118] The rolling resistance Ff

[0119] That is, the rolling resistance of the vehicle is mainly caused by the deformation of the tire and the road surface when the wheel rolls. In addition, there is friction between the tire and the road surface and the bearing inside the wheel shell. These deformations and frictions generated when the wheel rolls consume a certain internal force of the engine, forming rolling resistance. The rolling resistance is represented by Ff, which is related to the mass of the vehicle itself, the structure and air pressure of the tire, and the road surface properties.

[0120] Ff = Gη (1)

[0121] In the formula, G represents the total weight of the vehicle (N), and in this embodiment, the total weight of the vehicle is taken as an example when the vehicle is fully loaded; η represents the rolling resistance coefficient, η = η1η2η3, η1 is the tire surface coefficient, η2 is the tire pressure coefficient, and η3 is the road surface property coefficient. In this embodiment, under the condition of good asphalt or concrete pavement, standard tire and standard tire pressure, η takes the value of 0.012. Because the materials used in tunnels are different, low-friction materials are often used. Because the higher the friction performance, the greater the combustion toxicity, it cannot be used in tunnels. In this embodiment, the road surface rolling resistance coefficient η of the tunnel takes the value of 0.015.

[0122] The air resistance Fw

[0123] The air resistance is proportional to the shape of the vehicle, the projected area and the square of the speed. Because the airflow relative to the automobile does the flow motion in the process of vehicle driving, the pressure difference is generated in front and back of the automobile, and the friction between the air and the surface of the automobile, plus the airflow disturbance caused by indoor ventilation and cooling engine, etc. form the resistance. The air resistance is represented by Fw:

[0124] (2)

[0125] C d represents the air resistance coefficient, which is generally taken as 0.60-1.00 for a truck; A represents the windward area, i.e. the projected area in the direction of travel of the vehicle (m2), which is generally taken as 3.0-7.0 for a truck; v represents the relative speed, which can be approximately taken as the speed of the vehicle (m / s).

[0126] The slope resistance Fi

[0127] Since the force component of the total weight of the vehicle along the road surface direction forms resistance when the vehicle is climbing, this resistance is referred to as slope resistance, which is represented by Fi, and its value depends on the total weight of the vehicle and the longitudinal slope of the road. The slope resistance Fi can be represented as:

[0128] Fi = Gsinα (3)

[0129] In the formula, α is the angle between the road surface and the horizontal plane;

[0130] The road slope i is represented by the ratio of the slope height h and the base length s, i.e.:

[0131] (4)

[0132] The acceleration resistance Fj

[0133] The acceleration resistance, in actual situations, is due to the passive perception characteristics of the driver, i.e. when they subjectively perceive that the vehicle lacks climbing power, they will instinctively press the accelerator again to increase the power. In existing speed measurement and mapping software, this situation is accurately simulated, so the speed of the vehicle is a fluctuating curve, as shown in FIG. 2. From the curve, it can be seen that when the vehicle is accelerating on an uphill or adjusting the speed to maintain the existing speed, the inertia force that needs to be overcome is the acceleration resistance Fj. Taking the coefficient δ as the conversion coefficient of the mass of the vehicle after taking into account the moment of the rotational mass inertia force couple, the acceleration resistance (unit: N) of the vehicle can be written as: Figure 5

[0134] (5)

[0135] In the formula, δ represents the total coefficient of the inertia force of the vehicle, and its value can be represented as: δ = 1+ δ1 + δ2i ​, δ1 represents the influence coefficient of the inertia force of the automobile wheel, generally 0.03~0.05; δ2 represents the influence coefficient of the inertia force of the engine flywheel, generally 0.04~0.05 for a heavy-duty vehicle; ik is the gear ratio of the gearbox; m represents the total mass of the automobile, which is equal to the total weight of the vehicle when fully loaded in the specific example, and the unit is (kg); represents the driving acceleration, and the unit is (m / s2). .

[0136] Step three: obtaining the balance relationship model of the vehicle type through each resistance analyzed in step two, and calculating the calculation balance slope length; specifically including:

[0137] Step S301: according to the combined action of the traction force and the resistance when driving on the longitudinal slope, the vehicle reaches a balanced state under the action of the resultant force, and a quadratic function of the power factor D and the speed V is obtained, D = PV2 + QV+W;

[0138] Firstly, since the target vehicle is driven on the longitudinal slope under the combined action of the traction force and the resistance, the vehicle reaches a balanced state under the action of the resultant force, and the resistance of the target vehicle on the longitudinal slope can be decomposed into the rolling resistance Ff, the air resistance Fw, the slope resistance Fi, and the acceleration resistance Fj,

[0139] The sum of each resistance of the vehicle is

[0140] Ft = Fw + Ff + Fi + Fj (6)

[0141] The above formula is transformed to obtain

[0142] (7)

[0143] In order to eliminate the difference in the weight of the vehicle, the above formula is divided by the total weight of the vehicle G on both ends to obtain:

[0144] (8)

[0145] Let the left end of the above formula be D, then

[0146]

[0147] D is called the power factor, which represents the performance of the target vehicle on the sea level elevation to overcome the road resistance and the acceleration resistance per unit vehicle weight. The larger the value is, the greater the acceleration, climbing and road resistance overcoming ability of the automobile is, which is the main index of the traction performance of the vehicle.

[0148] When the traction force is equal to the resistance, the balance state is reached, and the above formula is substituted to obtain:

[0149] (9)

[0150] wherein

[0151] U represents the load rate, generally 80%~90%;

[0152] M represents the engine crank torque (N m);

[0153] γ represents the total gear ratio, γ = i0 *ik, i0 is the main transmission ratio, and ik is the transmission ratio of the gearbox;

[0154] η T represents the mechanical efficiency of the transmission system, the transmission efficiency is affected by multiple factors and changes, but can be regarded as a constant when analyzing the power performance of the automobile, generally 0.80~0.85 for a truck;

[0155] C d represents the air resistance coefficient, the air resistance coefficient of a truck is generally 0.6~1.0;

[0156] r represents the wheel radius (m), and the above formula can be transformed as follows:

[0157] (10)

[0158] wherein

[0159] Mmax represents the maximum torque (N m);

[0160] MN represents the torque corresponding to the maximum power, that is, MN = 9549 (N m);

[0161] nN represents the speed corresponding to the maximum power (r / min);

[0162] nM represents the speed corresponding to the maximum torque (r / min).

[0163] By merging and simplifying the complex coefficients, the power factor D can be expressed as a quadratic function of the speed V, that is:

[0164] D = PV2 + QV +W (11)

[0165] wherein

[0166]

[0167]

[0168]

[0169] The present embodiment takes load rate U = 90%, mechanical efficiency ηT = 0.85, and combines the technical parameters of the leading vehicle model EQ1228V19D2 load truck to calculate the relevant P, Q, W (P / Q / W is a constant coefficient, and after derivation of the above formula, P / Q / W is a constant) values, as shown in Table 1 below.

[0170]

[0171] Substitute the P, Q, W values of each gear into the above formula (6) D = PV2 + QV + W, to calculate the speed of the leading vehicle model EQ1228V19D2 load truck under different gears. By solving each resistance, the equilibrium speed can be obtained. In order to determine that each resistance value is close to the true value, various damping values are analyzed based on TruckSim simulation of various real conditions.

[0172] Since the power factor D is calculated and drawn based on sea level and vehicle full load conditions, if the road is not at sea level and the vehicle load does not reach the full load state, the difference in altitude will also cause deviation in vehicle performance output, so a correction coefficient λ is introduced to correct the power factor.

[0173] (12)

[0174]

[0175] In the formula: is the altitude coefficient, generally taken as = (1-2.26×10 -5 H) 5.3 , H is the altitude (m),

[0176] G is the total weight of the vehicle (N), in the present embodiment, the total weight of the vehicle is taken as the total weight of the vehicle (N) when the vehicle is fully loaded, and G' is the total weight of the vehicle (N) when the vehicle is actually loaded.

[0177] Then, the maximum speed, critical speed, and gear shifting speed of each gear are calculated

[0178] After deriving the functional relationship between the power factor D and the speed v and obtaining the power factor diagram of the leading vehicle model, in order to study the climbing speed characteristics of the leading vehicle model, theoretical analysis of the maximum speed, critical speed, and gear shifting speed corresponding to each gear is also required.

[0179] 1. Maximum speed Vmax

[0180] The maximum speed of a vehicle refers to the highest speed (km / h) that a car can reach when it is fully loaded and running on a dry, clean, flat, and good road (concrete or asphalt) under the condition that the wind speed is not greater than 3 m / s. When determining the maximum speed of a vehicle, the graphical method can be used to analyze the forces acting on the car and their balance relationship. See Figure 3 The driving force - running resistance balance diagram of a car with a 5-speed transmission is shown in the figure.

[0181] From the above figure, we can see that when the vehicle reaches the maximum speed, the uphill resistance and acceleration resistance should be zero. According to formula (6), F t = F w + F f ,

[0182] The intersection of the F t5 curve and the (F w + F f ) curve is Vmax. From the figure, we can also see that when the speed is lower than the maximum speed, the driving force is greater than the running resistance, so the car can use the remaining driving force to climb the hill, which is the principle of "reducing the gear to climb the hill".

[0183] In order to make the maximum speed of the main vehicle more intuitive, the following formula is used to calculate:

[0184] Vmax = 0.377

[0185] In the formula

[0186] n max ——The maximum speed of the engine of the car (r / min).

[0187] 2 、Critical speed Vk

[0188] According to the power characteristics Figure 4 , there is a maximum power factor Dmax for each gear of the vehicle, and the corresponding speed is called the critical speed. The speed of a certain gear can be obtained from the power characteristics Figure 4 , or it can be calculated using the following formula:

[0189] VK = -

[0190] The critical speed is the limit speed of the car. When the vehicle is running at a speed higher than the critical speed at a certain moment, if the road resistance F f + F iAdditional increase, the car can be on the original gear to reduce speed, to obtain greater D value to overcome the additional resistance, the resistance disappears can immediately improve to the original speed driving, this driving state is called stable driving. If the vehicle is driven below the critical speed, the road resistance is additionally increased, the car is driven at a lower speed and the D value is reduced. At this time, if the gear is not changed, the car will stop running due to engine stall. This state is called unstable driving.

[0191] Generally, the vehicle uses a critical speed greater than a certain gear as the driving speed to overcome the influence of additional resistance and continuously drives.

[0192] 3, shift speed V H

[0193] During the climbing process of the vehicle, the driver will add or reduce the gear according to the specific situation of the vehicle driving: the vehicle has difficulty in climbing due to insufficient power performance, and the vehicle runs smoothly and the road conditions allow, and the vehicle climbs with acceleration and gear increase. Due to the short time of gear shifting operation, the time experienced in the gear shifting process is often ignored, so whether it is acceleration or deceleration, the principle of shortest gear shifting time and continuous speed before and after gear shifting should be followed. The gear shifting speed of acceleration or deceleration is determined by the following method:

[0194] In the power characteristics Figure 4 If the power characteristics curves of the adjacent two gears intersect, the intersection speed is taken as the gear shifting speed V H . The power factor D n of a certain gear position intersects with the power factor D n+1 of the next gear position, the intersection speed (i.e. gear shifting speed) is V H , then:

[0195] Dn = Dn+1

[0196] PnV + Qn VH +Wn = Pn+1V + Qn+1VH +Wn+1

[0197] Substitute the P, Q and W values of the two gears into the above formula to obtain the gear shifting speed V H .

[0198] If the power characteristics curves of the adjacent two gears do not intersect, when the gear is accelerated in the nth gear, the gear shifting speed is taken as the highest speed Vmax(n) of the gear position, and the deceleration gear shifting speed is taken as the highest speed Vmax(n-1) of the (n-1)th gear. In this way, the driving speed of the vehicle is maximized under the premise of ensuring stable driving of the vehicle.

[0199] According to the above formula, the maximum speed Vmax(n), critical speed V k and shifting speed V H of the host vehicle in different gears can be calculated, as shown in Table 2.

[0200]

[0201] Step S302: The displacement of the vehicle climbing the slope is evenly divided into a plurality of units, each unit can be regarded as a uniform variable speed motion. For a long enough slope, after experiencing the maximum speed when entering the slope, the shifting speed during the process, and the change with the critical speed as the lower limit value, the final state that can be reached is the equilibrium speed. Thus, the equilibrium slope length S corresponding to the equilibrium speed can be solved by using the relevant theory of kinematics.

[0202] Because for an ideal uphill with a straight section in the front section, the vehicle has the maximum speed Vmax(n) when entering the slope. After experiencing the power drop when entering the slope, the vehicle reaches the shifting speed VH(n) after t0 time of travel. The vehicle needs to shift gears in time, and then repeats the process, travels for t(n) time, and the speed decreases again. Thus, the vehicle enters VH(n-1) and travels for t(n-1) time. Until after VH(n-i), the vehicle travels for t(n-i) time. The state that can be reached in the final state is the equilibrium speed Vp. Since the equilibrium speed is reached, the vehicle should also travel a certain distance. Generally, it is considered that t(x) of the distance should not be less than the sum of t0+t(n)+t(n-i), i.e., the vehicle should travel for a sufficient time at the equilibrium speed stage instead of entering the next slope section immediately after the vehicle enters the slope section. Therefore, the value t(x)=t0+t(n)+t(n-i) is taken. Thus, the equilibrium slope length S corresponding to the equilibrium speed can be solved by using the relevant theory of kinematics.

[0203] It should be noted that the critical speed Vk(n) is the minimum speed that can be traveled in a certain gear. When only theoretical calculation is performed, the equilibrium speed may be less than the critical speed Vk(n). Therefore, numerical constraints based on actual conditions are required.

[0204] When the vehicle travels on a long uphill slope, the driving speed of the vehicle has a small fluctuation, but the speed is stable to a certain extent. The speed of each longitudinal slope can be considered uniform without change when the slope length increases to a certain value. Therefore, each longitudinal slope has an equilibrium speed, and the minimum slope length that reaches the stable speed can be calculated.

[0205] S3021: Calculate the equilibrium speed of different slopes and different gears in different units

[0206] According to the principle of vehicle dynamics, the acceleration ɑ of the vehicle in different gears can be calculated by the following formula:

[0207] (13)

[0208] Ψ = 1 + δ1 + δ2i ; inertia force coefficient δ = 1 + δ1 + δ2i , and the inertia force coefficients of the dominant vehicle model in each gear are shown in Table 3:

[0209]

[0210] Then, the equilibrium speed of the next unit is calculated by acceleration. Although the vehicle is in variable speed motion during climbing, the displacement of the vehicle is divided into small units of 1 m in length by using the idea of calculus. Each unit can be regarded as uniform variable speed motion. The final speed v2 of the previous unit is used as the initial speed of the next unit. According to the basic theorem of kinematics, v2 = v0 2 + 2aS, the initial speed of the previous unit is v0.

[0211] Finally, from equation (11), D - Ψ = Pv2 + Qv + W - Ψ = 0, we get:

[0212] (14)

[0213] In the formula: Vp is the equilibrium speed, km / h, and Ψ is the road resistance coefficient. Assuming that the vehicle is running on a good asphalt or concrete road, the rolling resistance coefficient f = 0.01, and the altitude load correction coefficient λ = 0.90, the equilibrium speed Vp (km / h) of the sample vehicle under different slope and gear conditions can be obtained, as shown in Table 4.

[0214]

[0215] From Table 4, it can be concluded that the equilibrium speed in the ideal model under the condition of small traffic volume, good road conditions, and good weather conditions, and the driver can freely change the speed.

[0216] S3022: Calculate the equilibrium slope length

[0217] The displacement of the vehicle climbing is divided into small units. After considering the effect of acceleration, each unit can be regarded as uniform variable speed motion. By using the related theory of kinematics, the equilibrium slope length S corresponding to the equilibrium speed can be solved.

[0218] Substitute D = Pv2 + Qv + W into

[0219]

[0220] Move the term to the left side of the equation and integrate both sides to get:

[0221]

[0222] Let B = W - Then the above formula is:

[0223]

[0224] When Q2 - 4PB≥0 in the formula, the integral result is:

[0225]

[0226] When Q2 - 4PB<0 in the formula, the integral result is:

[0227] (14)

[0228] The above formula is the balance relationship model of the main truck type, and C in the two formulas is an integral constant.

[0229] Step four: According to the balance slope length, the longitudinal slope of the long uphill of the tunnel to be designed is divided into several sections, and the climbing slope, the gentle slope and the straight slope are designed for different types of situations. The parameter information of the tunnel to be designed is combined with various types of situations to calculate the carbon emission, so as to determine the slope design scheme of the long uphill of the tunnel.

[0230] The specific embodiment takes a tunnel group with a total length of 5.5 km as an example, the tunnel group design parameters are two-way two-lane, the lane width is set to 3.75 m, the asphalt concrete pavement, the pavement adhesion coefficient is 0.7, and the straight line section adopts 1.5% two-way road arch transverse slope.

[0231] The balance slope length determines the length of the analysis unit, which is an important part of the analysis method. According to relevant specifications and reference literature, considering various factors such as signboard setting, construction difficulty, driver sight distance, existing vehicle conditions, existing pavement material performance, tunnel light illumination, specification requirements and the like, especially considering the balance slope length of the balance speed, the specific example considers that the minimum analysis unit length of 500 m is suitable for the minimum analysis unit length of a certain engineering project in Chongqing area, and the slope has three main choices of climbing slope 5%, gentle slope 3% and straight slope 1.5%. According to the balance relationship model of the main truck type, it is analyzed that the minimum analysis unit length 500 m can cut the uphill section of the project into 11 sections, as shown in Figure 6 .

[0232] At the same time, as shown in Figure 7As shown, according to the general experience, there is a high upper and lower limit for the starting point and the end point, which can be adjusted by the front and rear road section adjustment, so there is no need to adjust the standard slope, such as the occurrence of 1.2% slope, which can be adjusted by adjusting the starting and ending point elevation to make the road starting and ending point meet the requirements. That is, a 100m slope, the original height difference is 1m, the height difference is 1.5m, and then the end point is adjusted by 0.5m.

[0233] Therefore, all possible design schemes can be obtained based on the balance relationship model, the carbon emission of each scheme is calculated, and the design schemes are compared. For example: the first segment slope is 5%, the second segment slope is 5%, then the slope of the segment is 1.5%, the slope of the segment is 3%, and the final tunnel segmentation in the range is the first scheme.

[0234] In the embodiment, it is assumed that the starting point elevation is 0±5m, the ending point elevation is 155±5m, and then three different slope combinations are used to form three embodiment schemes. In the three embodiment schemes, the large slope is placed in the front, middle and rear positions of the road section, and the three positions are named as slope type a, slope type b and slope type c. It should be noted that the slope type combination is limited and exhaustive, and can be compared by a computer program. In order to illustrate the combination of the three slope types, in order to facilitate understanding, only the comparison of slope type a, slope type b and slope type c is used to illustrate the beneficial effects of the present application. According to the conventional driving speed requirement in the tunnel, the slope and slope length distribution scheme of 40km / h, 60km / h and 80km / h is shown in Table 5.i1.2.3……11 represents the longitudinal slope of each segment, and S1.2.3……11 represents the slope length of each segment.

[0235] Table 5

[0236]

[0237] The climbing speed and displacement relationship curve of the main truck type is obtained by simulation, as shown in Figure 8 As shown, the segmented schematic diagram of slope type a.

[0238] Calculate carbon emission and Ecs reverse guide longitudinal slope design

[0239] According to the data summary of the previous work, the linear regression formula obtained by fitting is:

[0240] Speed component carbon emission formula: Ecs1= -0.01Vp 2 -Vp + 708

[0241] Slope correlation carbon emission formula: Ecs2= 0.0004i 2 -0.4342i + 133.74

[0242] Slope length carbon emission formula: Ecs3= 0.000002S 3 - 0.0078S 2 + 10.184S - 3107.1

[0243] Total carbon emission formula: Ecs = Ecs1 + Ecs2 + Ecs3 (15)

[0244] Ecs is the carbon emission prediction value, the unit is gCo2e / veh, veh is the traffic capacity unit vehicle, i is the road longitudinal slope, S is the equilibrium slope length, and Vp is the equilibrium speed.

[0245] The above three comparative examples are merged according to node segmentation for observation and statistics, the carbon emission Ecs of each position is calculated, and then the total carbon emission corresponding to the scheme is obtained. Table 6 is

[0246] The Ecs segmentation table of the design speed 80km / h scheme is shown in Table 7, and the Ecs segmentation table of the design speed 60km / h scheme is shown in Table 8.

[0247] Table 6

[0248]

[0249] Table 7

[0250]

[0251] Table 8

[0252]

[0253] The tunnel design speeds of the above three examples meet the specification requirements, and the total carbon emission can be calculated by the above formula (15). According to the carbon emission from low to high, they are sequentially sorted as 80-c, 80-b, 60-c, 60-b, 80-a, 40-c, 60-a, 40-b, and 40-a. From the carbon emission, it can be concluded that the design speed of 80km / h is adopted in the specific embodiment, and the slope type c is used as the slope combination, and the carbon emission is the lowest, which is only 470.6. The design speed of 40km / h is adopted, and the slope type a is used as the slope combination, and the carbon emission is the largest, which reaches 589.8. Compared with 470.6 of 80-c and 589.8 of 40-a, the carbon emission is saved by 20%, and the effect is very obvious.

[0254] As Figure 9 , Figure 10 and Figure 11As shown, the carbon emission of various slope types under the design speeds of 80km / h, 60km / h and 40km / h can also be displayed through a column chart, so as to intuitively understand the carbon emission of various slope designs and realize visualization.

[0255] Possibly, the step five of verifying the optimal slope design scheme determined in the embodiment by using the carbon emission mechanical parameters is further included.

[0256] The carbon emission mechanical parameters given according to the relevant specification documents are shown in Table 9.

[0257] Table 9: Partial mechanical parameters for calculating the carbon emission of urban bridges

[0258]

[0259] The data in the above table is converted, and the shift is 8h. In the embodiment, the length is 1.5km, and the design speed is 80km / h. It takes 0.01875h to pass, so 143437 / (8 / 0.01875)=336.18 (unit: gCo2, read as carbon dioxide equivalent), which is reliable from the perspective of dimension. From the perspective of numerical value, the numerical value used in the existing specification is an ideal value for driving on flat ground, without considering the additional carbon emission when climbing a slope.

[0260] Therefore, the long and large slope design can be guided from the perspective of carbon emission.

[0261] The technical solutions provided by the present application are described in detail above. The principles and implementation modes of the present application are described by applying specific examples in this paper. The above example is only applicable to help understand the method and core idea of the present application. It should be pointed out that for ordinary skilled persons in the technical field, some improvements and modifications can be made to the present application without departing from the principles of the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application.

Claims

1. A slope design method for long uphill sections of tunnels based on TruckSim, characterized in that: Includes the following steps: Step 1: Identify the target vehicles and obtain parameter information for each target vehicle and the tunnel to be designed; Step Two: Based on TruckSim simulation of the actual state of each target vehicle determined in Step One, analyze various resistance values, specifically including: S201: Based on the parameter information of the target vehicle, establish a vehicle model and a driving model using Trucksim; S202: Calculate the resistance value of each target vehicle based on the vehicle model and driving model; Step 3: Based on the resistance analyzed in Step 2, derive the vehicle's balance model and calculate the balance slope length; specifically including: S301: Based on the combined action of traction and resistance when driving on a longitudinal slope, the vehicle reaches a state of equilibrium under the action of the resultant force, and the quadratic function of the dynamic factor D and the speed V is derived, D = PV2 + QV + W, where P, Q, and W are constant coefficients. S302: Divide the vehicle's uphill displacement into multiple units. Each unit can be regarded as uniformly accelerated motion. Using the relevant kinematic theory, solve for the equilibrium slope length S corresponding to the equilibrium speed. Step 4: Divide the longitudinal slope of the long uphill section of the tunnel to be designed into several segments according to the balance slope length. Use three types of slopes—climbing slope, gentle slope, and straight slope—to design different types of situations. Combine the parameter information of the tunnel to be designed with the various types of situations to calculate the carbon emissions, thereby determining the optimal slope design scheme for the long uphill section of the tunnel.

2. The slope design method for long uphill tunnel sections based on TruckSim according to claim 1, characterized in that: S201: also includes establishing a road scene model.

3. The slope design method for long uphill tunnel sections based on TruckSim according to claim 1 or 2, characterized in that: It also includes step five, which verifies the slope design scheme using mechanical parameters of carbon emissions.

4. The slope design method for long uphill tunnel sections based on TruckSim according to claim 1 or 2, characterized in that: S202: Based on the vehicle model and driving model, the resistance values ​​experienced by each target vehicle are analyzed and calculated. Specifically, the resistance experienced by the target vehicle on the longitudinal slope includes rolling resistance Ff, air resistance Fw, slope resistance Fi, and acceleration resistance Fj. The rolling resistance Ff, or vehicle rolling resistance, is mainly generated by the deformation of the tire and the road surface when the wheel rolls. In addition, there is friction between the tire and the road surface as well as inside the wheel bearing. These deformations and frictions generated when the wheel rolls consume a certain amount of internal force from the engine, thus forming rolling resistance. The air resistance Fw is proportional to the shape of the vehicle, its projected area, and the square of its speed. As the airflow moves around the car during its operation, a pressure difference is generated between the front and rear of the car, and there is friction between the air and the car's surface. In addition, the airflow interference caused by indoor ventilation and engine cooling also contributes to the resistance. The slope resistance Fi is the resistance formed by the component of the total weight of a car along the road surface when the car goes uphill. The acceleration resistance Fj is the inertial force that a car needs to overcome when accelerating uphill or adjusting its speed to maintain its current speed.

5. The slope design method for long uphill tunnel sections based on TruckSim according to claim 4, characterized in that: The third point, 301, states that based on the combined effects of traction and resistance when driving on a longitudinal slope, the vehicle reaches equilibrium under the combined force, thus deriving a quadratic function of the dynamic factor D and velocity V: D = PV² + QV + W, specifically including: The sum of all resistances acting on the vehicle, Ft, is: Ft = Fw + Ff + Fi + Fj Transforming the above equation yields... To eliminate the difference in vehicle weight, divide both sides of the above equation by the total vehicle weight G to obtain: Let D be the left-hand side of the above equation, then . D is called the power factor, which characterizes the vehicle's performance in overcoming road resistance and acceleration resistance per unit weight at sea level. The larger this value, the greater the vehicle's acceleration, climbing ability, and ability to overcome road resistance. It is a key indicator of vehicle traction performance. An equilibrium state is reached when traction force equals resistance. Substituting into the above formula, we get: In the formula, U represents the load factor and M represents the engine crankshaft torque (N). m) and Y represent the total gear ratio, Y = i0 * ik, where i0 is the main drive ratio, ik is the gearbox ratio, and η T Indicates the mechanical efficiency of the transmission system, C d Let r represent the air resistance coefficient and r represent the wheel radius (m). Transforming the above formula, we get: In the formula, Mmax represents the maximum torque (N). m); MN represents the torque corresponding to the maximum power; nN represents the rotational speed (r / min) corresponding to the maximum power. nM represents the speed (r / min) corresponding to the maximum torque; By merging and simplifying the complexity coefficients, the dynamic factor D can be expressed as a quadratic function of the velocity V, i.e.: D = PV² + QV + W . . . In the formula, P, Q, and W are constant coefficients; Since the power factor D is calculated and plotted based on the standard value under the conditions of sea level and full vehicle load, if the road is not located at sea level and the vehicle load is not at full load, the difference in altitude will also have a deviation in the vehicle performance output. Therefore, a correction coefficient λ is introduced to correct the power factor. . In the formula: This is the altitude coefficient, generally taken as... =(1-2.26×10 -5 H) 5.3 H represents altitude (m). G is the total weight of the vehicle (N), and G' is the total weight of the vehicle when it is actually loaded (N).

6. The slope design method for long uphill tunnel sections based on TruckSim according to claim 1 or 2, characterized in that: S302: Divide the vehicle's uphill displacement into multiple units, each of which can be considered as uniformly accelerated motion. Using relevant kinematic theories, solve for the equilibrium slope length S corresponding to the equilibrium velocity; specifically including: S3021: Find the equilibrium velocity When a vehicle travels up a long longitudinal slope, its speed fluctuates slightly, but stabilizes after a certain point. Once the slope length reaches a certain value, the speed can be considered uniform and unchanging. Therefore, each longitudinal slope has an equilibrium speed, allowing us to determine the minimum slope length required to reach the stable speed. First, according to the principles of vehicle dynamics, the acceleration α of a vehicle in different gears is calculated using the following formula: In the formula: Ψ represents the road resistance coefficient. The inertial force coefficient δ = 1 + δ1 + δ2i ; Then, the equilibrium velocity of the next unit is calculated using acceleration. The final velocity v2 of the previous unit is used as the initial velocity of the next unit. According to the fundamental theorem of kinematics, v2 = v + 2aS, where the initial velocity of the previous unit is v0 and the final velocity of the previous unit is v2. Finally, according to D-Ψ = Pv² + Qv + W -Ψ = 0, we get: Where: Vp——balance speed, km / h, Ψ represents the road resistance coefficient; assuming the vehicle is traveling on a good asphalt or concrete road surface, the rolling resistance coefficient f = 0.01, and the altitude load correction coefficient λ = 0.90; S3021: Balanced Slope Length Divide the vehicle's displacement uphill into multiple units. After considering the effect of acceleration, each unit can be regarded as uniformly accelerated motion. Using the relevant kinematic theory, the equilibrium slope length S corresponding to the equilibrium speed can be solved. Substituting D = Pv² + Qv + W into . Rearranging the terms in the above equation and integrating both sides, we get: . Let B = W - Then the above formula is: . When Q² - 4PB ≥ 0, the integral result is: . When Q² - 4PB < 0, the integral result is: . The above equation is the balance relationship model of the dominant type of heavy-duty truck, where C is the integration constant.

7. The slope design method for long uphill tunnel sections based on TruckSim according to claim 1, characterized in that: Step four specifically includes: Based on the height of the long uphill section of the tunnel to be designed, three different slope combinations are used to form multiple slope types. According to the driving speed requirements in the tunnel, the climbing speed and displacement relationship of the main type of heavy-duty truck are calculated and simulated. The carbon emissions of various slope combinations are calculated, and the slope design method of the long uphill section of the tunnel is determined based on the obtained carbon emissions. The linear regression formula obtained from the fitting is as follows: Carbon emission formula for velocity component: Ecs1 = -0.01Vp 2 - Vp + 708 Slope-related carbon emission formula: Ecs² = 0.0004i 2 - 0.4342i + 133.74 Carbon emission formula based on slope length: Ecs3 = 0.000002S 3 - 0.0078S 2 +10.184S -3107.1 The formula for total carbon emissions is: Ecs = Ecs1 + Ecs2 + Ecs3. Where Ecs is the predicted carbon emission value, the unit is gCo2e / veh, veh is the traffic capacity in vehicles, i is the road longitudinal slope, S is the equilibrium slope length, and Vp is the equilibrium speed. The combination of slope types with the lowest carbon emissions is selected as the optimal slope design scheme.

8. A system based on the slope design method for long uphill sections of tunnels based on TruckSim as described in any one of claims 1 to 7, characterized in that: It includes a data acquisition module, a data modeling module, and an analysis and processing module. The data acquisition module is used to determine the target vehicle and obtain parameter information of each target vehicle. The data modeling module is used to simulate the real state of each target vehicle determined in step one based on TruckSim to analyze various resistance values, establish vehicle models and driving models based on TruckSim according to the parameter information of the target vehicles, and analyze and calculate the resistance values ​​of each target vehicle based on the vehicle models and driving models. The analysis and processing module is used to derive the vehicle's balance relationship model by analyzing various resistances and calculate the balance slope length. Based on the combined action of traction force and resistance when driving on a longitudinal slope, the vehicle reaches a balance state under the action of resultant force, and the quadratic function of dynamic factor D and velocity V is derived, D = PV2 + QV + W. The displacement of the vehicle climbing the slope is divided into sufficiently small units, each of which can be regarded as uniformly accelerated motion. Using relevant kinematic theories, the balance slope length S corresponding to the equilibrium speed is solved. Based on the equilibrium slope length, the longitudinal slope of the long uphill section of the tunnel to be designed is divided into several segments. Different types of slopes are designed using three types: climbing slope, gentle slope, and straight slope. The carbon emissions are calculated by combining the parameter information of the tunnel to be designed with various types of slopes, thereby determining the optimal slope design scheme for the long uphill section of the tunnel.

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