A full-stack design method for powertrain systems

Abstract

The present invention discloses a full-stack design method for a powertrain system. By establishing a performance volume characterization model of each sub-component in a power unit and an auxiliary system, and establishing a full-stack design platform for the powertrain system based on the coupling and matching relationship between the power unit and the auxiliary system parameters and the transmission relationship between the various components of the auxiliary system, and combining with a layout algorithm, after determining the boundary conditions and design requirements, the overall layout of the system, the structure of each component in the system, and the operating status of the system are simultaneously coupled and matched. By adding an optimization algorithm, the best selection of each component of the powertrain under the optimal layout can be given at the same time within a given optimization range, thereby realizing a full-stack design in which the front-end selection, mid-end layout, and back-end structure and operation design are simultaneously optimally combined.

Description

Technical Field

[0001] The present invention belongs to the technical field of intelligent optimization of vehicle power systems, and in particular relates to a full-stack design method for a powertrain system. Background Art

[0002] The development of new powertrains with faster speeds, higher power density, greater carrying capacity, and improved energy efficiency and environmental protection is a key trend in powertrain development. For example, diesel engines currently boast a specific power output of nearly 100 kW / L, fuel cells 20.9 kW / L, and solid-state batteries can reach 33 kW / L. For example, in the era of information warfare, armored vehicles must carry a large amount of electronic equipment, placing even higher demands on the compactness of powertrains. Powertrain system design involves the distribution of material, energy, and power flows within the powertrain, and its design must consider component matching and the matching of system and vehicle performance.

[0003] However, existing powertrain designs often involve repeated verification and iteration directly on the engine, transmission, motor, and cooling system, which is labor-intensive and prone to falling into local optimality. For example, CN104915472A proposes a simulation calculation method for optimizing an engine cooling system, CN103136423A provides an optimization design method for an engine cooling system, and CN115366929A proposes a method for optimizing the parameter configuration of a hydrogen fuel cell hybrid power system. The powertrain design of the above-mentioned prior art requires repeated iterative calculation and verification, and is limited to the optimization matching of operating parameters. It cannot simultaneously provide the optimal system selection, layout, system operating parameters, and component structural parameters that meet the design requirements, and the degree of optimization is limited. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention proposes a full-stack design method for a powertrain system to solve the problems existing in the above-mentioned prior art.

[0005] To achieve the above objectives, the present invention provides a full-stack design method for a powertrain system, comprising:

[0006] Establishing a selection and matching procedure for the power unit under the current power unit type, and calculating the power unit volume based on the selection and matching procedure;

[0007] Establishing an intelligent layout program for the auxiliary system topology, and generating a topology layout of the auxiliary system based on the intelligent layout program;

[0008] Establishing an integrated design program for the auxiliary system, and establishing an integrated design model for the auxiliary system based on the integrated design program; obtaining the total power consumption and total volume of the auxiliary system through the integrated design model;

[0009] establishing an optimization model for a powertrain system based on the power output of the power unit, the total power consumption of the auxiliary system, the volume of the power unit, and the total volume of the auxiliary system, and obtaining an iterative optimization result of an objective function value based on the optimization model;

[0010] Comprehensively evaluating the iterative optimization results to obtain the optimal design under the current layout;

[0011] Set constraints, and based on the optimal design and the constraints, repeat the steps of intelligent layout, integrated design, model optimization, and comprehensive evaluation to obtain the optimal layout topology, its component structural parameters, and system operating parameters;

[0012] Calculate the powertrain energy efficiency under the current power unit type. By traversing the calculation of all power unit types, the optimal powertrain sub-component type, structure, system layout and operating parameters are screened.

[0013] Preferably, based on the selection and matching program, the process of calculating the volume of the power unit includes:

[0014] Analyze the working condition information of the power unit to obtain the required operating parameter values ​​of the power unit;

[0015] Select and match the power unit and choose the device model with the highest efficiency under the conditions;

[0016] Based on the conditional operating parameters, the power unit volume is calculated.

[0017] Preferably, based on the intelligent layout program, the process of generating the topological structure layout of the auxiliary system includes:

[0018] Based on the intelligent layout program, matching the corresponding auxiliary system and determining the number of components of the auxiliary system;

[0019] Based on the number of components, a component node requirement model and an association matrix between nodes are established, and a topological structure layout of the auxiliary system is generated through the association matrix.

[0020] Preferably, based on the integrated design program, the process of establishing an integrated design model of the auxiliary system includes:

[0021] Setting boundary parameters and equipment performance parameters, and establishing a volume characterization model and a performance characterization model of each component of the auxiliary system based on the boundary parameters and equipment performance parameters;

[0022] Based on the volume characterization model and the performance characterization model, an integrated design model of the auxiliary system is established according to the parameter coupling matching relationship between the components.

[0023] Preferably, the process of establishing the optimization model of the powertrain system includes:

[0024] Obtaining a powertrain net output power based on the power unit output power and the total power consumption of the auxiliary system; obtaining a powertrain total volume based on the power unit volume and the total volume of the auxiliary system; and using the powertrain net output power and the powertrain total volume as objective functions;

[0025] Extracting original design parameters that affect net output power and volume, using the original design parameters as optimization variables, and setting boundary ranges of the optimization variables;

[0026] An optimization model of a powertrain system is established based on the optimization variables and the objective function.

[0027] Preferably, the process of comprehensively evaluating the iterative optimization results includes:

[0028] Comprehensively evaluating the iterative optimization results, wherein the iterative optimization results are a Pareto non-inferior solution set;

[0029] Select the overall optimal set of solutions and their corresponding optimization variable combinations.

[0030] Preferably, all power unit types include but are not limited to engine drive type, pure electric drive type, parallel hybrid type, series hybrid type, and hybrid type.

[0031] The present invention also provides an electronic device, comprising: a processor and a memory storing computer program instructions; when the processor executes the computer program instructions, the full-stack design method of the powertrain system is implemented.

[0032] The present invention also provides a computer storage medium having computer program instructions stored thereon, and when the computer program instructions are executed by a processor, the powertrain system full-stack design method is implemented.

[0033] Compared with the prior art, the present invention has the following advantages and technical effects:

[0034] The present invention proposes a full-stack design method for a powertrain system, which takes the power unit, auxiliary system topology layout, component structure and system operating parameters as the design objects. By establishing performance volume characterization models of each sub-component in the power unit and the auxiliary system, and establishing a full-stack design platform for the powertrain system based on the coupling and matching relationship between the power unit and the auxiliary system parameters and the transmission relationship between the various components of the auxiliary system; at the same time, combined with the layout algorithm, after determining the boundary conditions and design requirements, the overall layout of the system, the structure of each component in the system, and the system operating status are simultaneously coupled and matched. By adding the optimization algorithm, the best selection of each component of the powertrain under the optimal layout can be given at the same time within a given optimization range, realizing a full-stack design in which the front-end selection, mid-end layout and back-end structure and operation design are simultaneously optimally combined. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of this application. The exemplary embodiments and descriptions of this application are intended to explain this application and do not constitute an improper limitation on this application. In the accompanying drawings:

[0036] Figure 1 This is a flow chart of a full-stack design method for a powertrain system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0037] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0038] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0039] Example 1

[0040] like Figure 1 As shown, this embodiment provides a full-stack design method for a powertrain system, establishing an integrated design process based on the power unit, auxiliary system topology layout, and auxiliary system components, with the highest system static output power and the smallest system volume as the optimization goals. This achieves simultaneous design and development that takes into account multiple factors such as the power performance, compactness, and economy of the vehicle power system, solving the problem of neglecting one thing while focusing on another and being easily trapped in the local optimum during the traditional design and development stage. The present invention takes the optimal performance of the power system and the smallest volume as the optimization goals. Specifically, it includes the following steps:

[0041] S1. Establish a power plant design selection and matching procedure, as follows:

[0042] S1.1. Analyze the input working condition information to obtain the required operating parameter values ​​of the power unit.

[0043] S1.2. Select and match the power unit and, by comparing the performance efficiency curves, choose the device model with the highest efficiency under the conditions.

[0044] S1.3. Based on the conditional operating parameters, the power unit speed and output torque are obtained through the average value model, and the effective power is further obtained. Based on the selected device model, structural parameters such as specific power, number of strokes, and crank-connecting rod ratio are determined, and the minimum outer contour volume, i.e., the power unit volume, is further calculated.

[0045] S2. Establishing an intelligent layout program for the auxiliary system topology structure, including the following steps:

[0046] S2.1. Match the corresponding auxiliary system to the selected power unit type and determine the number of auxiliary system components.

[0047] S2.2. Establish the node demand model of each component and the node association matrix, and bring them into the layout algorithm program to generate the current auxiliary system topology layout and the pipeline flow and component inlet and outlet temperature information under the current layout.

[0048] S3. Establish an integrated design process for the auxiliary system, including the following steps:

[0049] S3.1. Based on the operating conditions of the vehicle power system, the boundary parameters, equipment performance parameters, and the operating parameters under the current layout determined by the layout algorithm are given as the initial design parameters.

[0050] S3.2. Establish different types of volume characterization models and performance characterization models for each component of the power assist system, and establish an integrated design model for the assist system based on the parameter coupling and matching relationship between the components.

[0051] In auxiliary system design, the radiator, intercooler, oil radiator, and transmission oil radiator establish temperature transfer relationships and circulation loop flow information through the flow of coolant. The fan's air volume, static pressure, outer diameter, and water pump flow are all matched according to the radiator and intercooler design requirements.

[0052] Engine water jacket outlet temperature T out.eng , high temperature radiator coolant inlet temperature T in.h , low temperature radiator coolant outlet temperature T out.l , Oil radiator coolant inlet temperature T in.oil , outlet temperature T out.oil , Transmission oil radiator coolant inlet temperature T in.tr The transfer relationship between them.

[0053] T out.eng =T in.h ;T out.l =T in.oil ;T out.oil =T in.tr ;

[0054] The flow rate of cooling air is determined by the heat balance equation according to the heat dissipation requirements of the cooling system, namely:

[0055]

[0056] Where Δt a ——The temperature rise of cooling air entering and leaving the water radiator, ℃, is generally within 30~50℃.

[0057] ρ a ——density of air, kg / m 3 ;

[0058] c p,a ——Specific heat capacity of air at constant pressure, kJ / (kg·℃).

[0059] The air volume that the fan needs to provide is determined by the volumetric efficiency of the cooling air entering the radiator at the fan outlet, that is,

[0060]

[0061] Where, η is the volumetric efficiency, which is generally taken as 0.8-0.9.

[0062] Similarly, the circulating volume flow rate of the engine cooling water, that is, the flow rate of the water pump, is also calculated according to the heat dissipation demand Φ of the cooling system by the heat balance equation, that is:

[0063]

[0064] Where, ρ w ——Density of cooling water, kg / m 3 ;

[0065] c p,w ——Specific heat capacity of cooling water at constant pressure, kJ / (kg·℃);

[0066] Δt w ——The temperature drop of cooling water in the cooling system, ℃. Generally, for closed forced circulation water system, Δt w The value is between 5 and 12℃.

[0067] The fan's outer diameter is a key parameter in cooling fan design. Its determination is related to the size of the radiator core. The fan impeller's rotational coverage of the radiator core should be between 45% and 60% of the core's frontal area.

[0068] S4. Establish a powertrain system optimization model, including the following steps:

[0069] S4.1. Extract the original design parameters that affect both net output power and volume, use them as optimization variables, use the volume function and power function as objective functions, and use the operating conditions of the vehicle power assist system components, heat dissipation requirements, and the range of optimization variables as constraints. Based on the operating conditions of the vehicle power system and actual production experience, establish an optimization model with the optimization variable boundary range and design constraints given.

[0070] Powertrain net output power P 总 :

[0071] P 总 =f(N e ,H1,H2,S1,S2,δ1,δ2,B1,B2,B3,B4,B5,L1,L2,L3,

[0072] n b ,q w ,G 1.h ,G 2.h ,G 1.l ,G 2.l ,G co1 ,G co2 ,G oil ,G tr ,P1,P2,T out.l )

[0073] Powertrain total volume characterization function V 总 :

[0074] V 总 =f(N e ,H1,H2,S1,S2,δ1,δ2,B1,B2,B3,B4,B5,L1,L2,L3,

[0075] n b ,q w ,G 1.h ,G 2.h ,G 1.l ,G 2.l ,G co1 ,G co2 ,G oil ,G tr ,P1,P2,T out.l )

[0076] In the above formula, the letters have the following meanings:

[0077] N e ——engine power, kW;

[0078] H1, H2——height of cold and hot side fins of intercooler, high temperature radiator and low temperature radiator, m;

[0079] S1, S2——intercooler, high temperature radiator, low temperature radiator cold and hot side pitch, m;

[0080] δ1,δ2——Thickness of cold and hot side fins of intercooler, high temperature radiator and low temperature radiator, m;

[0081] B1, B2——effective width of high-temperature radiator and low-temperature radiator core, m;

[0082] B3——effective width of intercooler core, m;

[0083] B4, B5 - effective width of the engine oil radiator and transmission oil radiator core, m;

[0084] L1, L2——effective length of high-temperature radiator and low-temperature radiator core, m;

[0085] L3——effective length of intercooler core, m;

[0086] n b ——Number of intercooler fin layers;

[0087] q w ——cold side air flow, kg / s;

[0088] G 1.h ,G 2.h ——Mass flow rate of coolant on the hot side of high-temperature radiator and low-temperature radiator, kg / m 2 ·s;

[0089] G 1.l ,G 2.l ——Air mass flow rate on the cold side of high-temperature radiator and low-temperature radiator, kg / m 2 ·s;

[0090] G co1 ,G co2 ——Mass flow rate of coolant on the cold side of oil radiator and transmission oil radiator, kg / m 2 ·s;G oil ,G tr ——Mass flow rate of engine oil and transmission oil, kg / m 2 ·s;

[0091] P1, P2——high / low temperature radiator hot side and cold side pressure, MPa;

[0092] T out.l ——Outlet temperature of cold side of low temperature radiator, °C;

[0093] Optimization goal:

[0094] min P 总 =f(N e ,H1,H2,S1,S2,δ1,δ2,B1,B2,B3,B4,B5,L1,L2,L3,

[0095] n b ,q w ,G 1.h ,G 2.h ,G 1.l ,G 2.l ,G co1 ,G co2 ,G oil ,G tr ,P1,P2,T out.l )

[0096] min V 总 =f(N e ,H1,H2,S1,S2,δ1,δ2,B1,B2,B3,B4,B5,L1,L2,L3,

[0097] n b ,q w ,G 1.h ,G 2.h ,G 1.l ,G 2.l ,G co1 ,G co2 ,G oil ,G tr ,P1,P2,T out.l )

[0098] Constraints:

[0099]

[0100] In the above constraints, ΔP I.air Indicates the pressure drop on the charge air side of the intercooler, kPa; ΔP coolant Indicates the pressure drop on the coolant side of the radiator, kPa; A s , A x Respectively represent the actual heat dissipation area and the required heat dissipation area; l coolant , l heat Respectively represent the coolant channel length and thermal fluid channel length of the engine oil / transmission oil radiator.

[0101] S4.2. Calculate the net power output of the powertrain based on the effective power of the power unit and the power consumption of the auxiliary system. Calculate the total volume of the powertrain based on the volume of the power unit and the volume of the auxiliary system. Determine the objective function values ​​based on the net power output of the powertrain and the total volume of the powertrain.

[0102] S4.3. Bring the objective function value into the heuristic algorithm for iterative optimization.

[0103] S5. Apply a comprehensive evaluation method to comprehensively evaluate the Pareto non-inferior solution set obtained after the multi-objective optimization, and select the overall optimal set of solutions and the corresponding optimization variable combination. This will result in the optimal matching of component structure selection and system operating status under the current layout.

[0104] S6. Based on the auxiliary system operating conditions and the flow configuration rules of the fluid system, the associated matrix is ​​generated. After the optimal structural parameters of the components and the system operating parameters are generated through the integrated design of the auxiliary system under the current layout, a new auxiliary system topology layout is generated according to the constraints. S2-S5 are repeated. After traversing all feasible layouts, the optimization is performed to output the optimal layout topology as well as the structural parameters of the components and the system operating parameters under this layout.

[0105] S7. Calculate the powertrain energy efficiency for the current power unit type and perform design calculations for new candidate power unit types, repeating S1-S6. After traversing all power unit types, screen them based on actual needs and output the optimal powertrain subcomponent type, structure, system layout, and operating parameters.

[0106] The power unit types may include engine drive, pure electric drive, parallel hybrid, series hybrid, and hybrid-parallel hybrid.

[0107] Beneficial effects of this embodiment:

[0108] This embodiment establishes mathematical models for representing the volume and power of different types of subcomponents within the auxiliary system, and matches the corresponding component models of the auxiliary system according to the selected power unit type. In combination with relevant graph theory, the connection sequence between the various components of the auxiliary system is represented in the form of an adjacency matrix to form the auxiliary system topology. By establishing a component node demand matrix, the energy flow and material flow relationship between the various components included in the fluid flow system along the coolant flow channel, and the coupling matching relationship between the various components, a node association matrix is ​​established. Programming software such as MATLAB is used to form an integrated design method for the auxiliary system. A double-layer nested heuristic algorithm can achieve multi-objective optimization within a given optimization variable range and output a Pareto optimal solution set. In combination with comprehensive evaluation methods such as the Topsis method, the optimal solution is selected to obtain the optimal auxiliary system layout, component structure, and system operating parameters for the current power unit type.

[0109] Due to the limited variety of power unit types, we choose to select them through traversal. After obtaining the optimal result under the current power unit type each time, we replace the new power unit type and repeat the operation until all candidate power unit types are completely traversed. In this way, we can obtain the optimal front-end power unit type, the optimal mid-end auxiliary system topology structure, and the optimal back-end auxiliary system component structural parameters and operating parameters under certain working conditions, thereby realizing the full-stack optimization design of the powertrain system.

[0110] The above are merely preferred embodiments of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A full-stack design method for a powertrain system, characterized in that: The following steps are involved: Establishing a selection and matching procedure for the power unit under the current power unit type, and calculating the power unit output power and the power unit volume based on the selection and matching procedure; Establishing an intelligent layout program for the auxiliary system topology, and generating a topology layout of the auxiliary system based on the intelligent layout program; Establishing an integrated design program for the auxiliary system, and establishing an integrated design model for the auxiliary system based on the integrated design program; obtaining the total power consumption and total volume of the auxiliary system through the integrated design model; establishing an optimization model of the powertrain system based on the power output of the power unit, the total power consumption of the auxiliary system, the volume of the power unit, and the total volume of the auxiliary system, and obtaining an iterative optimization result of the objective function based on the optimization model; The process of establishing an optimization model for a powertrain system includes: Obtaining a powertrain net output power based on the power unit output power and the total power consumption of the auxiliary system; obtaining a powertrain total volume based on the power unit volume and the total volume of the auxiliary system; and using the powertrain net output power and the powertrain total volume as objective functions; Extracting original design parameters that affect net output power and volume, using the original design parameters as optimization variables, and setting boundary ranges of the optimization variables; Establishing an optimization model of a powertrain system based on the optimization variables and the objective function; Comprehensively evaluating the iterative optimization results to obtain the optimal design under the current layout; Set constraints, and based on the optimal design and the constraints, repeat the steps of intelligent layout, integrated design, model optimization, and comprehensive evaluation to obtain the optimal layout topology, its component structural parameters, and system operating parameters; Calculate the powertrain energy efficiency under the current power unit type. By traversing the calculation of all power unit types, the optimal powertrain sub-component type, structure, system layout and operating parameters are screened.

2. The powertrain system full stack design method according to claim 1, characterized in that: Based on the selection and matching procedure, the process of calculating the power unit volume includes: Analyze the working condition information of the power unit to obtain the required operating parameter values ​​of the power unit; Select and match the power unit and choose the device model with the highest efficiency under the conditions; Based on the conditional operating parameters, the power unit volume is calculated.

3. The powertrain system full stack design method according to claim 1, characterized in that: Based on the intelligent layout program, the process of generating the topological layout of the auxiliary system includes: Based on the intelligent layout program, matching the corresponding auxiliary system and determining the number of components of the auxiliary system; Based on the number of components, a component node requirement model and an association matrix between nodes are established, and a topological structure layout of the auxiliary system is generated through the association matrix.

4. The powertrain system full stack design method according to claim 1, characterized in that: Based on the integrated design procedure, the process of establishing an integrated design model of the auxiliary system includes: Setting boundary parameters and equipment performance parameters, and establishing a volume characterization model and a performance characterization model of each component of the auxiliary system based on the boundary parameters and equipment performance parameters; Based on the volume characterization model and the performance characterization model, an integrated design model of the auxiliary system is established according to the parameter coupling matching relationship between the components.

5. The powertrain system full stack design method according to claim 1, characterized in that: The process of comprehensively evaluating the iterative optimization results includes: Comprehensively evaluating the iterative optimization results, wherein the iterative optimization results are a Pareto non-inferior solution set; Select the overall optimal set of solutions and their corresponding optimization variable combinations.

6. The powertrain system full stack design method according to claim 1, characterized in that: All power unit types include but are not limited to engine drive, pure electric drive, parallel hybrid, series hybrid, and hybrid-parallel hybrid.

7. An electronic device, characterized in that: The device includes: a processor and a memory storing computer program instructions; when the processor executes the computer program instructions, it implements the powertrain system full-stack design method according to any one of claims 1 to 6.

8. A computer storage medium, characterized in that The computer storage medium stores computer program instructions, which, when executed by a processor, implement the powertrain system full-stack design method according to any one of claims 1 to 6.

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