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

Abstract

The invention discloses a TrickSim-based gradient design method and system for a long uphill section of a tunnel, and the method comprises the steps: S1, determining target vehicles, and obtaining the parameter information of each target vehicle and a to-be-designed tunnel; s2, simulating the real state, determined in the S1, of each target vehicle based on TrickSim to analyze various resistance values, S3, obtaining a balance relation model of the vehicle model through the resistance analyzed in the S2, and calculating a balance slope length; and S4, the longitudinal slope of the long upslope of the tunnel to be designed is divided into a plurality of sections according to the balance slope length, different types of conditions are designed through the climbing slope, the gentle slope and the straight slope, the parameter information of the tunnel to be designed is combined with the various types of conditions to calculate the carbon emission, and therefore the optimal slope design scheme of the long upslope of the tunnel is determined. The longitudinal slope design of the tunnel is dominated from the angle of carbon emission, and comparison and selection of tunnel design schemes are facilitated.

Description

Technical Field

[0001] The present invention belongs to the field of longitudinal slope design methods for long uphill sections of tunnels, and particularly relates to a slope design method and system for long uphill sections of tunnels based on TruckSim. Background Art

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

[0003] Research shows that the uphill section of the longitudinal slope is the main section where vehicles generate carbon emissions, and carbon emissions can be reduced by controlling the alignment of the longitudinal slope section. Some scholars have studied the influence law of single longitudinal section line parameters such as slope on carbon emissions.

[0004] For example, Kanok Boriboonsomsin conducted on-road vehicle experiments. The disadvantage is that it is limited by actual conditions and only considered one type of vehicle, namely small cars. Emrah Demir also studied the impact of slope on exhaust emissions. However, the number of road samples in the on-road vehicle experiments is very limited, all based on a single longitudinal slope rather than a continuously changing longitudinal slope.

[0005] Subsequently, some scholars carried out research on continuous longitudinal slope sections. For example, Jinliang Xu conducted on-road vehicle experiments to study the carbon emissions of small cars traveling back and forth on continuous longitudinal slope sections at a constant speed. However, it still cannot solve the two congenital disadvantages of on-road vehicle experiments. One is that the types of vehicles are few, only considering one type of vehicle, namely small cars. The other is that parameter collection can only be based on existing roads in reality and does not have simulation forward-looking.

[0006] There is also an important problem that there are differences in the pavement materials between tunnels and ordinary roads. Typically, if a tunnel is paved with asphalt, due to the harm of toxic smoke generated by combustion in a closed space being much greater than that in an open space, a large amount of flame retardant additives need to be added, or a cement pavement needs to be selected. Therefore, the friction coefficients of tunnel pavements and ordinary roads are different, which will seriously affect the calculation of vehicle carbon emissions. Existing research has not considered this factor. Therefore, there are certain errors in the existing research on the longitudinal slope of long tunnels going uphill, which is not convenient to provide an effective reference basis for the subsequent slope design of long tunnels. Summary of the Invention

[0007] Aiming at the deficiencies of the existing technology, the purpose of the present invention is to provide a slope design method and system for long uphill sections of tunnels based on TruckSim, analyze the comprehensive influence of the longitudinal section line combination and vehicle driving state on carbon emissions, dominate the tunnel longitudinal slope design from the perspective of carbon emissions, and facilitate the comparison and selection of design schemes.

[0008] To achieve one of the above objects, the technical solution adopted by the present invention is as follows:

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

[0010] Step 1: Determine the target vehicles and obtain the parameter information of each of the target vehicles and the tunnel to be designed;

[0011] Step 2: Analyze various resistance values based on the actual states of the target vehicles determined in S1 by simulating with TruckSim, specifically including:

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

[0013] S202: Analyze and calculate the resistance values suffered by each target vehicle according to the vehicle model and the driving model;

[0014] Step 3: Obtain an equilibrium relationship model of vehicle types from the resistances analyzed in S2 and calculate the equilibrium slope length; specifically including:

[0015] S301: According to the combined action of traction force and resistance when driving on a longitudinal slope, when the vehicle reaches an equilibrium state under the combined force, obtain a quadratic function of the dynamic factor D and the speed Ve, D = PV 2 +QV+W, where P, Q, and W are constant coefficients;

[0016] S302: Divide the displacement of the vehicle climbing the slope into multiple units, and each unit can be regarded as a uniformly variable motion. Using the relevant theories of kinematics, solve for the equilibrium slope length S corresponding to the equilibrium speed;

[0017] Step 4: Divide the longitudinal slope of the long uphill section of the tunnel to be designed into several segments according to the equilibrium slope length. Use three types of gradients, namely the climbing gradient, the transition gradient, and the flat gradient, 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, so as to determine the optimal gradient design scheme for the long uphill section of the tunnel.

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

[0019] Further, it also includes Step 4, using the mechanical parameters of carbon emissions to verify the gradient design scheme.

[0020] Further, in S202: Analyze and calculate the resistance values suffered by each target vehicle according to the vehicle model and the driving model, specifically including: The resistance suffered by the target vehicle on the longitudinal slope includes the rolling resistance F f, air resistance \(F_w\), gradient resistance \(F_i\) and acceleration resistance \(F_j\).

[0021] The rolling resistance \(F_f\), that is, the 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 and inside the wheel hub bearing. These deformations and frictions generated when the wheel rolls will consume a certain internal force of the engine, forming the rolling resistance.

[0022] The air resistance \(F_w\) is proportional to the shape, frontal projected area and the square of the speed of the vehicle. During the vehicle's driving process, the air flow makes a flow-around motion relative to the vehicle, generating a pressure difference before and after the vehicle and the friction between the air and the vehicle surface, plus the resistance caused by the air flow interference due to indoor ventilation and engine cooling.

[0023] The gradient resistance \(F_i\), when the vehicle goes uphill, the resistance formed by the component force of its total gravity along the road surface direction is called the gradient resistance.

[0024] The acceleration resistance \(F_j\), when the vehicle accelerates uphill or adjusts its speed to maintain the existing speed, the inertial force that needs to be overcome is the acceleration resistance \(F_j\).

[0025] Furthermore, the 301: According to the vehicle being under the combined action of traction and resistance when driving on a longitudinal slope, and the vehicle reaching an equilibrium state under the combined force, a quadratic function of the dynamic factor D and the speed V is obtained, \(D = PV\) 2 +QV + W, specifically including:

[0026] Statistical sum of each resistance \(F\) received by the vehicle t is

[0027] F t = F w + F f + F i + F j

[0028] Transform the above formula to get

[0029]

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

[0031]

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

[0033]

[0034] D is called the dynamic factor, which characterizes the performance of the target vehicle in overcoming road resistance and acceleration resistance per unit vehicle weight at sea level elevation. The larger this value is, the greater the vehicle's ability to accelerate, climb slopes, and overcome road resistance. It is the main indicator of the vehicle's traction performance. When the traction force is equal to the resistance, it reaches a balanced state. Substituting into the above formula, we get:

[0035]

[0036] In the formula, U represents the load rate, M represents the engine crankshaft torque (N·m), Y represents the total transmission ratio, Y = i0 * ik, i0 is the main drive ratio, ik is the gearbox ratio, η T represents the mechanical efficiency of the transmission system, C d represents the air resistance coefficient, r represents the wheel radius (m). Transforming the above formula, we can get:

[0037]

[0038] In the formula, M max represents the maximum torque (N·m);

[0039] M N represents the torque corresponding to the maximum power;

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

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

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

[0043] D = PV 2 + QV + W

[0044]

[0045] In the formula, P, Q, and W are constant coefficients;

[0046] Since the dynamic factor D is calculated and plotted according to the standard values at sea level and when the vehicle is fully loaded, if the road location is not at sea level and the vehicle load does not reach the full load state, due to the difference in altitude, there will also be deviations in the vehicle performance output. Therefore, a correction coefficient λ is introduced to correct the dynamic factor;

[0047]

[0048] In the formula: ξ is the altitude coefficient, generally taking ξ = (1 - 2.26×10 -5 H) 5.3, where H is the altitude (m), G is the total vehicle weight (N), and G’ is the total gravity of the vehicle during actual loading (N).

[0049] Further, S302: Divide the displacement of the vehicle climbing the slope into multiple units. Each unit can be regarded as a uniformly variable motion. Using the relevant theories of kinematics, solve for the equilibrium slope length S corresponding to the equilibrium speed; specifically including:

[0050] S3021: Calculate the equilibrium speed

[0051] When the vehicle is driving on a long uphill slope, its driving speed fluctuates slightly, but after reaching a certain level, the speed becomes stable. For each uphill slope, when the slope length increases to a certain value, its speed can be considered to be uniform and unchanged. Therefore, each uphill slope has an equilibrium speed, and thus the minimum slope length to reach the stable speed can be calculated.

[0052] First, according to the vehicle dynamics principle, the acceleration ɑ of the vehicle in different gears is calculated by the following formula:

[0053]

[0054] In the formula: Ψ represents the road resistance coefficient Inertia force coefficient

[0055] Then, calculate the equilibrium speed of the next unit through the acceleration. 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. In the formula, the initial speed of the previous unit is v0, and the final speed of the previous unit is v2;

[0056] Finally, according to D - Ψ = Pv 2 + Qv + W - Ψ = 0, and the solution is:

[0057]

[0058] In the formula: Vp - equilibrium speed, km / h, Ψ represents the road resistance coefficient. Assume the vehicle is driving 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: Equilibrium slope length

[0059] Divide the displacement of the vehicle climbing the slope into multiple units. After considering the influence of acceleration, each unit can be regarded as a uniformly variable motion. Using the relevant theories of kinematics, the equilibrium slope length S corresponding to the equilibrium speed can be solved;

[0060] Substitute D = Pv 2 + Qv + W into

[0061]

[0062] Transpose the above formula and integrate both sides to obtain:

[0063]

[0064] Let Then the above formula becomes:

[0065]

[0066] When Q 2 - 4PB > 0 in the formula, the integration result can be obtained as:

[0067]

[0068] When Q 2 - 4PB < 0 in the formula, the integration result can be obtained as:

[0069]

[0070] The above formula is the balance relationship model of the leading truck models. C in the two formulas is the integration constant.

[0071] Furthermore, the specific steps of step four include:

[0072] According to the height of the long uphill section of the tunnel to be designed, combine three different gradients into various gradient types. According to the driving speed requirements in the tunnel, calculate and simulate to obtain the climbing speed and displacement relationship of the leading truck models, calculate the carbon emissions of various gradient combinations, and determine the gradient design method for the long uphill section of the tunnel based on the obtained carbon emissions;

[0073] According to the linear regression formula obtained by fitting,

[0074] Speed component carbon emission formula: Ecs1 = - 0.01Vp 2 - Vp + 708

[0075] Gradient correlation carbon emission formula: Ecs2 = 0.0004i 2 - 0.4342i + 133.74

[0076] Slope length carbon emission formula: Ecs3 = 0.000002S 3 - 0.0078S 2 + 10.184S - 3107.1

[0077] Total carbon emission formula: Ecs = Ecs1 + Ecs2 + Ecs3,

[0078] Among them, Ecs is the predicted value of carbon emissions, with the unit of gCo2e / veh, where veh is the unit of traffic capacity in vehicles, i is the road longitudinal slope, S is the balanced slope length, and Vp is the balanced speed;

[0079] Select the combination of slope types with the minimum carbon emissions as the optimal slope design plan.

[0080] To achieve the second above-mentioned purpose, the technical solution adopted by the present invention is as follows:

[0081] A system based on the slope design method for the long uphill section of a tunnel based on TruckSim described above, including a data acquisition module, a data modeling module, and an analysis and processing module,

[0082] The data acquisition module is used to determine the target vehicle and obtain the parameter information of each target vehicle;

[0083] The data modeling module is used to analyze various resistance values based on the true state of each target vehicle determined by TruckSim simulation of S1, 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 values received by each target vehicle according to the vehicle model and the driving model;

[0084] The analysis and processing module is used to obtain the balance relationship model of the vehicle type by analyzing the various resistances, calculate the balanced slope length; according to the combined action of traction and resistance when driving on the longitudinal slope, the vehicle reaches a balanced state under the combined force, and obtain the quadratic function of the dynamic factor D and the speed V, D = PV 2 + QV + W; divide the displacement of the vehicle climbing the slope into small enough units, each unit can be regarded as a uniformly variable motion, use the relevant theories of kinematics to solve the balanced slope length corresponding to the balanced speed S; divide the longitudinal slope of the long uphill section of the tunnel to be designed into several sections according to the balanced slope length, use three slope design types of climbing slope, gentle slope, and straight slope, combine the parameter information of the tunnel to be designed with various types of situations to calculate the carbon emissions, so as to determine the optimal slope design plan for the long uphill section of the tunnel.

[0085] The remarkable effect of the present invention is:

[0086] Simulations of various vehicles and slopes were completed based on Trucksim software to analyze the comprehensive impact of vertical alignment combinations and vehicle driving states on carbon emissions, and to dominate the longitudinal slope design from the perspective of carbon emissions to facilitate the comparison of design schemes. At the same time, the differences between tunnel materials and traditional road materials were fully considered. Different friction coefficients were designed for the road surface, and the vehicle resistance was different accordingly. The analysis results obtained by considering the road surface design were more accurate, improving the data accuracy and being closer to the real value, providing effective support for the design data of long tunnel slopes and promoting the construction of green transportation and the sustainable development of the whole society. Description of the Drawings

[0087] Figure 1 is the flowchart of Specific Embodiment 1;

[0088] Figure 2 is the force diagram of a heavy truck on a longitudinal slope in Specific Embodiment 1;

[0089] Figure 3 is the driving force - running resistance balance diagram of a car with a 5 - speed transmission in Specific Embodiment 1;

[0090] Figure 4 is the power characteristic diagram in Specific Embodiment 1;

[0091] Figure 5 is the vehicle speed fluctuation curve diagram in Specific Embodiment 1;

[0092] Figure 6 is the schematic diagram of a tunnel divided into 11 sections in Specific Embodiment 1;

[0093] Figure 7 is Figure 6 the schematic diagram of the height difference slope of the tunnel;

[0094] Figure 8 is Figure 6 the schematic diagram of one of the design schemes of the tunnel design;

[0095] Figure 9 is the bar chart of carbon emissions of three tunnel design schemes with a design speed of 80 km / h in Specific Embodiment 1;

[0096] Figure 10 is the bar chart of carbon emissions of three tunnel design schemes with a design speed of 60 km / h in Specific Embodiment 1;

[0097] Figure 11 is the bar chart of carbon emissions of three tunnel design schemes with a design speed of 40 km / h in Specific Embodiment 1. Detailed Implementation Manner

[0098] The specific embodiments and working principles of the present invention will be further described in detail below with reference to the accompanying drawings.

[0099] See Figures 1 to 11 As shown, a gradient design method for a long uphill section of a tunnel based on TruckSim includes the following steps:

[0100] Step 1: Determine the target vehicles and obtain the parameter information of each of the target vehicles and the tunnel to be designed;

[0101] The target vehicle can be either a car in traditional research or a passenger car or a large truck. The approximate carbon emission values of various vehicle types given in existing relevant literature are only approximate values or equal values selected, which are not sufficient to guide the design of the long uphill section of the specific tunnel. Therefore, a calculation method for improving the carbon emission value of the target vehicle based on TruckSim is adopted to improve the accuracy of the carbon emission value.

[0102] The carbon emissions of a vehicle on a long uphill section are related to various factors such as tire force, vehicle power, and driving habits. Since the vehicle rarely performs obvious acceleration and deceleration movements on a long uphill section, the resistance it receives tends to be stable and can be regarded as a balanced speed. Therefore, a method for inversely calculating carbon emissions based on the balanced speed is proposed. The parameter information of the target vehicle includes the total vehicle weight when fully loaded, the load weight, the fuel type, the tire performance, the vehicle power, the engine efficiency, the type of vehicle transmission system, the driver behavior pattern, the vehicle service life, and the maintenance status. The parameter information of the tunnel to be designed includes the type of tunnel pavement material, 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 flow stability, and the weather conditions.

[0103] For example, the Dongfeng truck EQ1228V19D2 with a total mass of 22.00t, a rated load capacity of 12.00t, a curb weight of 8.30t, and a power-to-mass ratio of 8.05kW / t, the Dongfeng passenger car EQ6750H3G1 with a total mass of 7.85t and a curb weight of 5.28t, the Dongfeng car DFM6473M5F6BEV with a total mass of 2.13t and a curb weight of 1.72t, and other different vehicle types can be selected as target vehicles. The parameters of the tunnel to be designed are two-way two lanes, with a set lane width of 3.75m, an asphalt concrete pavement, a road adhesion coefficient of 0.7, and a two-way crown cross slope of 1.5% for the straight section.

[0104] Step 2. Analyze various resistance values based on the real state of each target vehicle determined in Step 1 by simulating with TruckSim, specifically including:

[0105] S201: Establish a vehicle model and a driving model based on Trucksim according to the parameter information of the target vehicle;

[0106] (1) Establishing vehicle model

[0107] Using Trucksim, the main purpose of body modeling is to parametrically describe the sprung mass and load of the vehicle. To describe the body, the body mass center coordinate system must first be defined. The origin of the body mass center coordinate system is the body mass center, the vehicle forward direction is the X-axis, forward is positive, the plumb (vertical) direction is the Z-axis, upward 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 the Trucksim software. This specific embodiment uses step S1 to build the body mass center coordinate system of this project based on the leading model Dongfeng truck EQ1228V19D2, and inputs the pavement material, tunnel speed limit, tunnel long slope requirements, etc.

[0108] Trucksim controls the vehicle load by inputting the sprung mass of the target vehicle model. In automotive engineering, the vehicle body is the largest "rigid body" in the vehicle system, and the movement of the vehicle body can be regarded as the movement of the vehicle. Strictly speaking, the vehicle body is the sprung mass of the vehicle, that is, the part above the suspension. However, in addition to the vibration of the vehicle body and the longitudinal and lateral roll, the sprung mass is required. In the planar motion of the vehicle such as longitudinal displacement, lateral displacement and steering, the engine, chassis and body have the same motion, so the body mass can include the engine and chassis mass. In this case, the body mass is the mass of the whole vehicle. The study of the uphill problem of the vehicle can be regarded as the vehicle doing planar motion on the xoz plane. Therefore, the sprung mass of the dominant model can be set as the mass of the whole vehicle. In this specific embodiment: the mass of the whole vehicle is the gross weight of the vehicle when it is fully loaded. The total mass of Dongfeng truck EQ1228V19D2 is 22000kg.

[0109] (2) Determine the driver model

[0110] According to relevant surveys, drivers generally take gear changes based on the vehicle speed and the sound of the engine. In the model, they are adjusted to an ideal state. The model uses an automatic gear shifting method, which means that by default, when the vehicle's power factor reaches the maximum value of the gear, the driver decisively takes gear shifting measures, and the gear shifting operation time is negligible. The "throttle" control in the driver model is set to automatic, which means that the driver of the dominant model, the heavy-duty truck, always presses the throttle to the ideal state during the climbing process.

[0111] Possibly, the step S201: establishing a vehicle model and a driving model based on Trucksim further includes establishing a road scene model. By constructing a road scene model according to the tunnel parameters to be designed, the accuracy of the measurement data is further improved. The construction of the road scene model mainly considers three factors: road geometric features, road surface adhesion coefficient, and road super elevation. The experimental section is in a straight line, with a total road length of 5.5 km, two-way two lanes, a set lane width of 3.75 m, an asphalt concrete road surface, and a road surface adhesion coefficient of 0.7. According to relevant specifications and references, various factors such as sign settings, construction difficulty, driver's sight distance, existing vehicle conditions, existing road surface material properties, and specification requirements are considered for the road, especially the balance slope length for balancing speed.

[0112] S202: Analyze and calculate the resistance values suffered by each target vehicle according to the vehicle model and the driving model; specifically including: the resistance suffered by the target vehicle on the longitudinal slope is decomposed into rolling resistance F f , air resistance Fw, gradient resistance Fi, and acceleration resistance Fj.

[0113] The rolling resistance Ff

[0114] That is, the 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 hub bearing. These deformations and frictions generated when the wheel rolls consume a certain internal force of the engine, forming the rolling resistance. The rolling resistance is represented by Ff, and its value is related to the vehicle's own mass, tire structure and air pressure, and road surface properties.

[0115] F f = Gη (1)

[0116] In the formula, G represents the total vehicle weight (N). In this specific embodiment, the total vehicle weight is taken as the total vehicle weight 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 specific embodiment, under the conditions of good asphalt or concrete road surface, standard tires, and standard tire pressure, η is taken as 0.012. Since the tunnel materials are different and materials with low friction performance are mostly used because the higher the friction performance, the greater the combustion toxicity and thus cannot be used in the tunnel. In this specific embodiment, the rolling resistance coefficient η of the tunnel road surface is taken as 0.015.

[0117] The air resistance Fw

[0118] The air resistance is proportional to the shape of the vehicle, the frontal projected area, and the square of the speed. During the vehicle's driving process, the air flow makes a flow-around motion relative to the vehicle, generating a pressure difference before and after the vehicle and the friction between the air and the vehicle surface. In addition, the air flow interference caused by indoor ventilation and engine cooling forms the resistance. The air resistance is represented by Fw:

[0119]

[0120] In the formula, C d represents the air resistance coefficient. Generally, the air resistance coefficient of a heavy truck is taken as 0.60 - 1.00; A represents the frontal area, that is, the projected area (m2) in the vehicle driving direction. Generally, the frontal area of a heavy truck is taken as 3.0 - 7.0; v represents the relative speed, and can be approximately taken as the driving speed of the vehicle (m / s).

[0121] The gradient resistance Fi

[0122] When the vehicle is going uphill, the resistance formed by the component force of its total gravity along the road surface direction is called the gradient resistance, denoted as Fi. Its value depends on the total gravity of the vehicle and the longitudinal gradient of the road surface. The gradient resistance Fi can be expressed as:

[0123] F i = Gsinα (3)

[0124] In the formula, α is the angle between the road surface and the horizontal plane;

[0125] The road gradient i is expressed as the ratio of the slope height h to the bottom length s, that is:

[0126]

[0127] The acceleration resistance Fj

[0128] Acceleration resistance. In actual situations, due to the passive perception characteristics of drivers, that is, when they subjectively perceive that the vehicle lacks climbing power, they will instinctively step on the accelerator pedal again to increase power. And in existing speed measurement and mapping software, this situation will be accurately simulated. Therefore, the speed of the vehicle is a fluctuating curve, as shown in Figure 5 shown. From this curve graph, it can be obtained that when the vehicle is accelerating uphill or adjusting its speed to maintain the existing speed, the inertial force that needs to be overcome is the acceleration resistance Fj. Using the coefficient δ as the vehicle mass conversion coefficient after considering the inertial force couple moment of the rotating mass, the vehicle acceleration resistance (unit: N) can be written as:

[0129]

[0130] In the formula, δ represents the total coefficient of the vehicle inertial force, and its value can be expressed as: δ1 represents the influence coefficient of the inertial force of the vehicle wheels, generally taken as 0.03 - 0.05; δ2 represents the influence coefficient of the inertial force of the engine flywheel. Generally, for heavy trucks, it is taken as 0.04 - 0.05; ik is the transmission ratio. m represents the total mass of the vehicle. In this specific example, the total mass of the vehicle is equal to the total weight of the vehicle when fully loaded, with the unit of (kg); Indicates the driving acceleration, with the unit of (m●s -2 ).

[0131] Step 3: Obtain the balance relationship model of the vehicle type based on the various resistances analyzed in Step 2, and calculate the calculated balance slope length; specifically including:

[0132] Step S301: According to the combined action of traction and resistance when driving on a longitudinal slope, the vehicle reaches a balanced state under the combined force, and a quadratic function of the dynamic factor D and the speed V is obtained, D = PV 2 +QV+W;

[0133] First, since the target vehicle is under the combined action of traction and resistance when driving on a longitudinal slope, and the vehicle reaches a balanced state under the combined force, the resistance received by the target vehicle on the longitudinal slope can be decomposed into rolling resistance F f , air resistance Fw, gradient resistance Fi, and acceleration resistance Fj,

[0134] The sum of the various resistances received by the vehicle is counted as

[0135] F t =F w +F f +F i +F j (6)

[0136] Transform the above formula to get

[0137]

[0138] To eliminate the difference in vehicle weight, divide both ends of the above formula by the total vehicle weight G to get:

[0139]

[0140] Let the left end of the above formula be D, then

[0141]

[0142] D is called the dynamic factor, which characterizes the performance of the target vehicle in overcoming road resistance and acceleration resistance per unit vehicle weight at sea level elevation. The larger this value, the greater the acceleration, climbing, and road resistance overcoming ability of the vehicle, and it is the main indicator of vehicle traction performance.

[0143] When the traction force is equal to the resistance, it reaches a balanced state. Substitute it into the above formula to get:

[0144]

[0145] In the formula

[0146] U represents the load factor, generally taking 80% - 90%;

[0147] M represents the engine crankshaft torque (N·m);

[0148] γ represents the total gear ratio, γ = i0 * ik, where i0 is the main drive ratio and ik is the gearbox ratio;

[0149] η T represents the mechanical efficiency of the transmission system. The transmission efficiency varies due to multiple factors, but it can be regarded as a constant when analyzing the power performance of the vehicle. Generally, for a heavy-duty truck, it is 0.80 - 0.85;

[0150] C d represents the air resistance coefficient. Generally, the air resistance coefficient of a heavy-duty truck is taken as 0.6 - 1.0;

[0151] r represents the wheel radius (m). Transforming the above formula gives:

[0152]

[0153] In the formula

[0154] M max represents the maximum torque (N·m);

[0155] M N represents the torque corresponding to the maximum power, that is n N represents the rotational speed corresponding to the maximum power (r / min);

[0156] n M represents the rotational speed corresponding to the maximum torque (r / min).

[0157] By merging and simplifying the complex coefficients, the power factor D can be expressed as a quadratic function of the speed V, that is:

[0158] D = PV 2 +QV + W (11)

[0159] In the formula

[0160]

[0161] In this specific embodiment, with a load factor U = 90%, a mechanical efficiency ηT = 0.85, and combined with the technical parameters of the leading vehicle model EQ1228V19D2 heavy-duty truck, the relevant P, Q, W values (P / Q / W are constant coefficients, and after the derivation of the above formula, P / Q / W are all constants) are calculated as shown in Table 1 below.

[0162] Gear position <![CDATA[i k > P Q W Ⅰ 8.015 <![CDATA[-7.941×10 -3 > <![CDATA[9.497×10 -2 > <![CDATA[2.813×10 -2 > Ⅱ 4.878 <![CDATA[-1.791×10 -3 > <![CDATA[3.518×10 -2 > <![CDATA[1.712×10 -2 > Ⅲ 2.844 <![CDATA[-3.560×10 -4 > <![CDATA[1.196×10 -2 > <![CDATA[9.981×10 -3 > Ⅳ 1.710 <![CDATA[-7.833×10 -5 > <![CDATA[4.323×10 -3 > <![CDATA[6.001×10 -3 > Ⅴ 1.000 <![CDATA[-1.664×10 -5 > <![CDATA[1.478×10 -3 > <![CDATA[3.509×10 -3 > Ⅵ 0.853 <![CDATA[-1.079×10 -5 > <![CDATA[1.076×10 -3 > <![CDATA[2.994×10 -3 >

[0163] Substitute the P, Q, W values of each gear into the above formula (6) D = PVe 2In +QVe+W, the speed of the leading model EQ1228V19D2 truck can be calculated at different gears. By calculating each resistance, the balance speed can be obtained. To ensure that each resistance value is close to the true value, TruckSim is used to simulate various real states and analyze various damping values.

[0164] Since the power factor D is calculated and plotted based on the standard values at sea level and when the vehicle is fully loaded, if the road location is not at sea level and the vehicle load does not reach the full load state, due to the difference in altitude, there will also be deviations in the vehicle performance output. Therefore, a correction coefficient λ is introduced to correct the power factor.

[0165]

[0166] In the formula: ξ is the altitude coefficient, generally taking ξ=(1 - 2.26×10 -5 H) 5.3 , H is the altitude (m), G is the total vehicle weight (N). In this specific embodiment, the total vehicle weight is taken as the total vehicle weight (N) when the vehicle is fully loaded, and G’ is the total gravity of the actual vehicle when it is loaded.

[0167] Then, find the maximum speed, critical speed, and shift speed of each gear

[0168] After deriving the functional relationship between the power factor D and the speed v and obtaining the power factor diagram of the leading model, for the convenience of studying the climbing speed characteristics of the leading model, theoretical analysis of the maximum speed, critical speed, and shift speed corresponding to each gear is also required.

[0169] 1. Maximum speed Vmax

[0170] The maximum speed of the vehicle refers to the maximum driving speed (km / h) that the vehicle can reach when driving fully loaded on a dry, clean, straight, and good road surface (concrete or asphalt) under the condition that the wind speed is not greater than 3 m / s. When determining the maximum speed of the vehicle, the force and its balance relationship during vehicle driving can be analyzed by the graphical method. See Figure 3 As shown in the driving force - driving resistance balance diagram of a vehicle with a 5 - speed transmission.

[0171] From the above figure, we can see that when the vehicle reaches the maximum speed, its uphill resistance and acceleration resistance should both be zero. From formula (6), we know that F t =F w +F f ,

[0172] F t5 curve and (F w +F f) The intersection point of the curves is Vmax. It can also be seen from the figure that when the vehicle speed is lower than the maximum speed, the driving force is greater than the running resistance, so the vehicle can use the remaining driving force to climb the slope. This is the principle of "shifting down to rush up the slope".

[0173] To make the maximum speed of the leading vehicle type more intuitive, the following formula is used for calculation:

[0174]

[0175] In the formula

[0176] n max —— The maximum rotational speed of the vehicle engine (r / min).

[0177] 2. Critical speed Vk

[0178] According to the power characteristics Figure 4 it can be known that 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 calculated by the following formula:

[0179]

[0180] The critical speed is the limit speed of vehicle driving. When the vehicle is driving at a speed higher than the critical speed at a certain moment, if the road resistance F f + F i increases additionally, the vehicle can reduce the speed in the original gear to obtain a larger D value to overcome the additional resistance, and can immediately increase the speed to the original speed after the resistance disappears. This driving state is called stable driving. If the vehicle is driving at a speed lower than the critical speed and the road resistance increases additionally, the vehicle decelerates and the D value decreases accordingly. At this time, if the gear is not shifted, the vehicle will stop due to engine flameout. This state is called unstable driving.

[0181] Usually, the vehicle adopts a speed higher than the critical speed of a certain gear as the driving speed to overcome the influence of additional resistance and drive continuously.

[0182] 3. Shifting speed V H

[0183] During the vehicle climbing process, due to different road resistances, the driver will perform gear up and down operations according to the specific driving conditions of the vehicle: when the vehicle power performance is insufficient and it is difficult to climb the slope, decelerate and shift down; when the vehicle is driving smoothly and the road conditions permit, accelerate and shift up to climb the slope. Since the shifting operation time is short and the time experienced during the shifting process is often ignored, whether it is accelerating or decelerating, the principle should be the shortest shifting time and continuous speed before and after shifting. The shifting speed for accelerating or decelerating is determined as follows in this article:

[0184] In terms of dynamic characteristics Figure 4 if the dynamic characteristic curves of two adjacent gears intersect, the speed at the intersection point is taken as the shifting speed V H . The dynamic factor D of a certain gear n intersects with the dynamic factor D of the next gear n+1 , and the intersection speed (i.e., the shifting speed) is V H , then we have:

[0185] D n = D n+1

[0186]

[0187] Substitute the P, Q, and W values of the two gears into the above formula to obtain the shifting speed V H .

[0188] If the dynamic characteristic curves of two adjacent gears do not intersect, when accelerating and shifting gears in the nth gear, the shifting speed is taken as the maximum speed Vmax(n) of this gear, and the decelerating shifting speed is the maximum speed Vmax(n - 1) of the (n - 1)th gear. In this way, the driving speed of the vehicle can reach the maximum on the premise of ensuring stable driving of the vehicle.

[0189] According to the above formula, the maximum speed Vmax(n), critical speed V k and shifting speed V H of the main vehicle model in different gears can be obtained, as shown in Table 2 below.

[0190]

[0191] Step S302: Divide the displacement of the vehicle climbing the slope into multiple units. Each unit can be regarded as a uniformly variable motion. For a sufficiently long slope length, after experiencing the maximum speed at the start of 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. In this way, the relevant theories of kinematics can be used to solve the equilibrium slope length S corresponding to the equilibrium speed;

[0192] For an ideal uphill slope with a flat section at the front, the vehicle has a maximum speed Vmax(n) when entering the slope. After experiencing a power drop when entering the slope and traveling for a time t0, it reaches the shift speed VH(n) and needs to shift gears in a timely manner. Then, this process is repeated, traveling for a time t(n), at which point the speed drops again. Therefore, it enters VH(n - 1) and travels for a time t(n - 1), until after VH(n - i) and then travels for a time t(n - i). The state that can be reached at the end state is the equilibrium speed Vp. Since the equilibrium speed is reached, the vehicle should travel a certain distance. Generally, it is considered that the t(x) of this section of the distance should not be less than the sum of t0 + t(n) + t(n - 1), that is, the vehicle should travel for a sufficient period of time at the equilibrium speed stage, rather than immediately entering the next slope section from one slope section. Therefore, taking t(x) = t0 + t(n) + t(n - i), the relevant theories of kinematics can be used to solve the equilibrium slope length S corresponding to the equilibrium speed;

[0193] It should be noted that the critical speed Vk(n) is the minimum speed that a certain gear can travel. This is because when calculating only from a theoretical perspective, it is possible that the equilibrium speed is less than the critical speed Vk(n). Therefore, numerical constraints should be based on actual situations.

[0194] When the vehicle is traveling on a long uphill slope, its driving speed fluctuates slightly, but after reaching a certain level, the speed becomes stable. When the slope length of each uphill slope increases to a certain value, its speed can be considered to be uniform and unchanged. Therefore, each uphill slope has an equilibrium speed, and thus the minimum slope length to reach the stable speed can be calculated.

[0195] S3021: Calculate the equilibrium speeds of different slopes and different gears for different units

[0196] First, according to the vehicle dynamics principle, the acceleration ɑ of the vehicle in different gears can be calculated by the following formula:

[0197]

[0198] In the formula: Ψ represents the road resistance coefficient Inertia force coefficient Combined with Table 3, the inertia force coefficients of each gear of the leading vehicle type are as shown in Table 3 below:

[0199]

[0200]

[0201] Then, the equilibrium speed of the next unit is calculated based on the acceleration. Although the vehicle is undergoing variable-speed motion during the climbing process, by applying the idea of calculus, the displacement of the vehicle is evenly divided into tiny units with a length of 1 m. Each unit can be regarded as undergoing uniformly variable motion, and the final speed v2 of the previous unit is used as the initial speed of the next unit. According to the basic kinematic theorem v2 = v0 2 + 2aS, where the initial speed of the previous unit is v0;

[0202] Finally, from formula (11), it can be obtained that D - Ψ = Pv 2 + Qv + W - Ψ = 0, and the solution is:

[0203]

[0204] In the formula: Vp —— equilibrium 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, the equilibrium speed Vp (km / h) of the sample vehicle under different gradients and different gear conditions can be obtained as shown in Table 4 below.

[0205]

[0206] From Table 4, the equilibrium speed in the ideal model can be obtained under the condition of low traffic volume, good road surface conditions, good climate conditions, and when the driver can freely change the speed.

[0207] S3022: Calculate the equilibrium slope length

[0208] The displacement of the vehicle during climbing is evenly divided into sufficiently small units. After considering the influence of acceleration, each unit can be regarded as undergoing uniformly variable motion. Using the relevant theories of kinematics, the equilibrium slope length S corresponding to the equilibrium speed can be solved.

[0209] Substitute D = Pv 2 + Qv + W into

[0210]

[0211] Transpose the above formula and integrate both sides to get:

[0212]

[0213] Let Then the above formula becomes:

[0214]

[0215] When Q 2 - 4PB > 0 in the formula, the integration result can be obtained as:

[0216]

[0217] When Q in the formula 2 -4PB < 0, the integral result can be obtained as follows:

[0218]

[0219] The above formula is the balance relationship model of the leading vehicle type of the heavy truck. C in the two formulas is the integration constant.

[0220] Step 4: Divide the longitudinal slope of the long uphill of the tunnel to be designed into several sections according to the balance slope length. Use three types of slopes, namely 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, so as to determine the slope design scheme of the long uphill of the tunnel.

[0221] Taking a tunnel group with a total length of 5.5 km as an example in this specific embodiment, the design parameters of the tunnel group are two-way two lanes. The lane width is set to 3.75 m, the asphalt concrete pavement, the pavement adhesion coefficient is 0.7, and the straight section uses a 1.5% two-way crown slope.

[0222] The balance slope length determines the length of the analysis unit and is an important part of the analysis method. According to relevant specifications and references, considering various factors such as sign setting, construction difficulty, driver's sight distance, existing vehicle conditions, existing pavement material performance, tunnel lighting, and specification requirements, especially considering the balance slope length of the balance speed, this example believes that the minimum analysis unit length suitable for segmentation in a certain engineering project in a certain area of Chongqing is 500 m. There are three main options for the slope, namely the climbing slope of 5%, the gentle slope of 3%, and the flat slope of 1.5%. According to the balance relationship model of the leading vehicle type of the heavy truck, it is analyzed that the minimum analysis unit length is 500 m, and a certain uphill section of this engineering project can be cut into 11 sections, as shown in Figure 6 shown.

[0223] At the same time, as Figure 7 shown, according to general experience, there are upper and lower limits of height at the starting point and the ending point, which can be connected smoothly by adjusting the front and rear road sections. Therefore, there is no need to adjust the standard slope. For example, if a slope of 1.2% appears, the starting and ending elevations of the road can be adjusted to meet the requirements. That is, for a 100 m slope, the original height difference is 1 m, using a slope of 1.5%, the height difference is 1.5 m, and then the ending point is raised by 0.5 m.

[0224] Therefore, all possible design solutions can be obtained based on the balance relationship model, and the carbon emissions of various solutions can be calculated separately, and then the design solutions can be compared. For example: the slope of the first section is 5%, the second section is 5%, then the slope of the nth section is 1.5%, and the slope of the mth section is 3%. Finally, if the 11 sections divided by the tunnel can meet the requirements, it is the first solution.

[0225] In this specific embodiment, it is assumed that the starting elevation is 0 ± 5m and the ending elevation is 155 ± 5m. Then, three different slopes are combined to form three embodiment solutions. In the three embodiment solutions, the large slopes are respectively placed at the front, middle, and rear positions of the section, and the three positions are correspondingly named slope type a, slope type b, and slope type c. It should be noted that it is obvious that the slope type combinations are limited and can be enumerated, and numerical comparison can be performed by a computer program. To illustrate the combinations of the three slope types formed thereby, for the sake of easy understanding, only the three cases of slope type a, slope type b, and slope type c are compared here to illustrate the beneficial effects of the present invention. According to the conventional driving speed requirements in the tunnel, the slope and slope length distribution schemes for 40 km / h, 60 km / h, and 80 km / h are shown in Table 5 below. i 1.2.3...11 represents the longitudinal slope of each section, and S1.2.3...11 represents the slope length of each section.

[0226] Table 5

[0227]

[0228] The climbing speed and displacement relationship curve of the leading truck model is obtained through simulation, see Figure 8 as shown in the sectional view of slope type a.

[0229] Calculate the carbon emissions and use Ecs to inversely guide the longitudinal slope design

[0230] According to the data summary of the previous work, the linear regression formula obtained by fitting is:

[0231] Speed component carbon emission formula: Ecs1 = -0.01Vp 2 -Vp + 708

[0232] Slope correlation carbon emission formula: Ecs2 = 0.0004i 2 -0.4342i + 133.74

[0233] Slope length carbon emission formula: Ecs3 = 0.000002S 3 -0.0078S 2 +10.184S - 3107.1

[0234] Total carbon emission formula: Ecs = Ecs1 + Ecs2 + Ecs3(16)

[0235] Ecs is the predicted carbon emission value, with the unit of gCo2e / veh, where veh is the traffic capacity unit (number of vehicles), i is the road longitudinal slope, S is the balanced slope length, and Vp is the balanced speed.

[0236] The above three comparative embodiments are segmented and merged by node for easy observation and statistics. The segmented values of carbon emissions Ecs at each position are calculated respectively, and then the total carbon emissions corresponding to the scheme are obtained by summarization. Table 6 below is the Ecs segmentation table for the scheme with a design speed of 80 km / h, Table 7 below is the Ecs segmentation table for the scheme with a design speed of 60 km / h, and Table 8 below is the Ecs segmentation table for the scheme with a design speed of 40 km / h.

[0237] Table 6

[0238] Project features AB BC CD DE EF FG Slope type a 89.6 44 47 49 39 41 Slope type b 39 41 38 40 42 78 Slope type c 39 41 38 40 42 34 Project features GH HI IJ JK KL Total Slope type a 43 44 43 38 40 517.6 Slope type b 41 42.8 44.8 38 40 484.6 Slope type c 35.7 40 41.4 42.9 76.6 470.6

[0239] Table 7

[0240] Project features AB BC CD DE EF FG Slope type a 98.6 46 50 51 41 43 Slope type b 42 46 40 42 44 78 Slope type c 42 46 40 42 44 35 Project features GH HI IJ JK KL Total Slope type a 43 45.5 48 40 41.9 548 Slope type b 43 45 47 40 41.9 512.7 Slope type c 38.2 42 43.5 45 76.6 499

[0241] Table 8

[0242]

[0243]

[0244] The tunnel design speeds of the above three embodiments all meet the specification requirements. It can be calculated from the above formula (16) that from the perspective of the total carbon emissions, in ascending order of carbon emissions, they are 80-c, 80-b, 60-c, 60-b, 80-a, 40-c, 60-a, 40-b, 40-a respectively. From the carbon emissions, it can be concluded that in this specific embodiment, when the design speed is 80 km / h and the slope type c is used as the slope combination, the carbon emissions are the lowest, only 470.6. When the design speed is 40 km / h and the slope type a is used as the slope combination, the carbon emissions are the highest, reaching 589.8. Comparing 470.6 of 80-c with 589.8 of 40-a, the carbon emissions are saved by 20%, and the effect is very obvious.

[0245] As Figure 9 、 Figure 10 and Figure 11 shown, the carbon emissions of various slope types in the cases of design speeds of 80 km / h, 60 km / h, and 40 km / h can also be displayed through a bar chart, which is convenient for intuitively understanding the carbon emissions of various slope type designs and realizing visualization.

[0246] Possibly, it further includes step five, using the mechanical parameters of carbon emissions to verify the optimal slope design scheme determined in this specific embodiment.

[0247] The mechanical parameters of carbon emissions given according to relevant standard documents are shown in Table 9 below.

[0248] Table 9 Partial mechanical parameters for calculating carbon emissions of urban bridges

[0249]

[0250] Convert the data in the above table. One work shift = 8h. In this embodiment: for a length of 1.5 km and passing through at a designed speed of 80 km / h, it takes 0.01875 h. So, 143437 / (8 / 0.01875) = 336.18 (the unit is gCo2, read as carbon dioxide mass equivalent). Judging from the perspective of dimension, this embodiment is reliable. Judging from the numerical perspective, the value adopted in the existing standard is an ideal value for flat-road driving without considering the additional carbon emissions during climbing.

[0251] Thus, it is possible to provide reverse guidance for the design of long and steep slopes from the perspective of carbon emissions.

[0252] The above has introduced the technical solution provided by the present invention in detail. Specific examples are used herein to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only applicable to helping understand the method and its core idea of the present invention. It should be noted that for those of ordinary skill in the art of this technology, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A slope design method for a long uphill section of a tunnel based on TruckSim, characterized in that: The steps include: Step 1: Determine the target vehicle and obtain parameter information of each target vehicle and the tunnel to be designed; Step 2: Analyze various resistance values ​​based on the actual state of each target vehicle determined in step 1 by TruckSim simulation, including: S201: Establishing a vehicle model and a driving model based on Trucksim according to the parameter information of the target vehicle; S202: Analyze and calculate the resistance value of each target vehicle according to the vehicle model and the driving model; Step 3: Obtain the balance relationship model of the vehicle model through the resistance analyzed in step 2, and calculate the balance slope length; specifically including: S301: According to the combined effect of traction and resistance when driving on a longitudinal slope, the vehicle reaches a state of equilibrium under the combined effect of the force, and the quadratic function of the power factor D and the speed Ve is obtained, D = PV 2 +QV+W, where P, Q, and W are constant coefficients; S302: Divide the displacement of the vehicle climbing the slope into multiple units, each unit can be regarded as uniformly accelerated motion, and use the relevant kinematics theory to solve the equilibrium slope length S corresponding to the equilibrium speed; Step 4: Divide the longitudinal slope of the long uphill tunnel to be designed into several sections according to the balanced slope length. Use the climbing slope, gentle slope and straight 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, so as to determine the optimal slope design plan for the long uphill tunnel.

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

3. The slope design method for a long uphill section of a tunnel based on TruckSim according to claim 1 or 2, characterized in that: The method also includes step five of verifying the slope design scheme using carbon emission mechanical parameters.

4. The slope design method for a long uphill section of a tunnel based on TruckSim according to claim 1 or 2, characterized in that: S202: Analyze and calculate the resistance value of each target vehicle based on the vehicle model and the driving model, specifically including: the resistance of the target vehicle on the longitudinal slope includes rolling resistance F f , air resistance Fw, slope resistance Fi and acceleration resistance Fj, The rolling resistance Ff, i.e. 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 in the wheel shell bearing. These deformations and frictions generated when the wheel rolls consume a certain amount of internal force of the engine, forming rolling resistance; The air resistance Fw is proportional to the shape of the vehicle, the area of ​​the orthographic projection and the square of the speed. The airflow moves around the vehicle during driving, resulting in a pressure difference in front of and behind the vehicle, friction between the air and the surface of the vehicle, and resistance caused by airflow interference caused by indoor ventilation and cooling of the engine. The slope resistance Fi is the resistance formed by the component force of the total gravity along the road surface when the car goes uphill. The acceleration resistance Fj is the inertia force that needs to be overcome when the vehicle accelerates uphill or adjusts its speed to maintain the current speed.

5. The slope design method for a long uphill section of a tunnel based on TruckSim according to claim 4, characterized in that: 301: According to the combined effect of traction and resistance when driving on a longitudinal slope, the vehicle reaches a state of equilibrium under the combined effect of the force, and the quadratic function of the power factor D and the speed V is obtained, D = PV 2 +QV+W, specifically including: Calculate the sum of all resistances F on the vehicle t F t =F w +F f +F i +F j Transforming the above formula, we can get To eliminate the difference in vehicle weight, divide both ends of the above equation by the vehicle's gross weight G to obtain: Let the left side of the above equation be D, then D is called the dynamic factor, which represents the performance of the target vehicle at sea level, per unit vehicle weight to overcome road resistance and acceleration resistance. The larger this value is, the greater the ability of the vehicle to accelerate, climb and overcome road resistance. It is the main indicator of vehicle traction performance. When the traction force is equal to the resistance, the equilibrium state is reached. Substituting it into the above formula, we get: Where U represents the load rate, M represents the engine crankshaft torque (N·m), Y represents the total speed ratio, Y=i0*ik, i0 is the main transmission speed ratio, ik is the gearbox speed 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 into: Where M max Indicates the maximum torque (N·m); M N Indicates the torque corresponding to the maximum power; n N Indicates the speed corresponding to the maximum power (r / min); n M Indicates the speed corresponding to the maximum torque (r / min); By combining and simplifying the complex coefficients, the dynamic factor D can be expressed as a quadratic function of the speed V, that is: D=PV 2 +QV+W Where P, Q, and W are constant coefficients; Since the dynamic factor D is calculated and drawn based on the standard value at sea level and when the vehicle is fully loaded, if the road is not at sea level and the vehicle load is not fully loaded, the difference in altitude will also cause deviations in vehicle performance output, so the correction coefficient λ is introduced to correct the dynamic factor; Where: ξ is the altitude coefficient, generally ξ=(1-2.26×10 -5 H) 5.3 ,H is the altitude (m), G is the gross vehicle weight (N), and G' is the total gravity of the vehicle when the vehicle is actually loaded (N).

6. The slope design method for a long uphill section of a tunnel based on TruckSim according to claim 1 or 2, characterized in that: S302: Divide the displacement of the vehicle climbing the slope into multiple units, each unit can be regarded as uniformly accelerated motion, and use the relevant theories of kinematics to solve the equilibrium slope length S corresponding to the equilibrium speed; specifically including: S3021: Find the equilibrium speed When a vehicle is traveling on a long longitudinal slope, its speed fluctuates slightly, but after a certain degree, the speed is stable. When the length of each longitudinal slope increases to a certain value, its speed can be considered to be uniform and unchanged. Therefore, each longitudinal slope has a balanced speed, so the minimum slope length to achieve a stable speed can be calculated. First, according to the principle of vehicle dynamics, the acceleration ɑ of the vehicle in different gears is calculated by the following formula: Where: Ψ represents the road resistance coefficient Inertia coefficient Then, the equilibrium velocity of the next unit is calculated by the acceleration, and the final velocity v2 of the previous unit is used as the initial velocity of the next unit. According to the basic theorem of kinematics, v2 = v 2 0+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=Pv 2 +Qv+W-Ψ=0, the solution is: Where: Vp is the equilibrium speed, km / h, Ψ is the road resistance coefficient. Assuming that the vehicle is driving on a good asphalt or concrete road, the rolling resistance coefficient f = 0.01, and the altitude load correction coefficient λ = 0.90; S3021: Balanced slope length The displacement of the vehicle climbing the slope is divided into multiple units. After considering the influence of acceleration, each unit can be regarded as uniformly accelerated motion. Using the relevant theories of kinematics, the equilibrium slope length S corresponding to the equilibrium speed can be solved; D=Pv 2 +Qv+W substitution Move the terms in the above equation and integrate both sides to get: make Then the above formula is: When Q 2 When -4PB>0, the integral result is: When Q 2 When -4PB<0, the integral result is: The above formula is the equilibrium relationship model of the dominant type of heavy-duty trucks, and C in both formulas is the integral constant.

7. The slope design method for a long uphill section of a tunnel based on TruckSim according to claim 1, characterized in that: The step 4 specifically includes: According to the height of the long uphill section of the tunnel to be designed, three different slopes are combined into a combination of multiple slope types. According to the driving speed requirements in the tunnel, the climbing speed and displacement relationship of the dominant truck model is calculated and simulated, and the carbon emissions of various slope combinations are calculated. The slope design method of the long uphill section of the tunnel is determined based on the various carbon emissions obtained. The linear regression formula obtained by fitting is as follows: Velocity component carbon emission formula: Ecs1 = -0.01Vp 2 -Vp+708 Slope correlation carbon emission formula: Ecs2 = 0.0004i 2 -0.4342i+133.74 Slope length carbon emission formula: Ecs3 = 0.000002S 3 -0.0078S 2 +10.184S-3107.1 Formula for total carbon emissions: Ecs = Ecs1 + Ecs2 + Ecs3, Among them, Ecs is the predicted value of carbon emissions, the unit is gCo2e / veh, veh is the vehicle capacity unit, i is the longitudinal slope of the road, S is the equilibrium slope length, and Vp is the equilibrium speed; The slope type combination with the lowest carbon emissions is selected as the optimal slope design solution.

8. A system for designing the slope of a long uphill section of a tunnel based on TruckSim according to any one of claims 1 to 7, characterized in that: It includes data acquisition module, data modeling module and 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 analyze various resistance values ​​based on the real state of each target vehicle determined by S1 by simulating 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; The analysis and processing module is used to obtain the balance relationship model of the vehicle model by analyzing various resistances and calculate the balance slope length; according to the combined effect of traction and resistance when driving on the longitudinal slope, the vehicle reaches a balance state under the combined force, and obtains the quadratic function of the power factor D and the speed V, D=PV 2 +QV+W; Divide the displacement of the vehicle climbing the slope into sufficiently small units. Each unit can be regarded as uniformly accelerated motion. Using the relevant theories of kinematics, solve the equilibrium slope length S corresponding to the equilibrium speed; The longitudinal slope of the long uphill tunnel to be designed is divided into several sections according to the balanced slope length. Different types of slope designs are made using climbing slope, gentle slope and straight slope. The parameter information of the tunnel to be designed is combined with various types of situations to calculate the carbon emissions, thereby determining the optimal slope design scheme for the long uphill tunnel.

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