阅读说明：本技术 一种轮毂液压混动商用车动力域系统及其控制方法 (Power domain system of hub hydraulic hybrid commercial vehicle and control method thereof ) 是由 曾小华 张轩铭 毕道坤 宋大凤 黄钰峰 杨东坡 钱琦峰 武庆涛 李敦迈 段朝胜 于 2021-10-25 设计创作，主要内容包括：本发明提供了一种轮毂液压混动商用车动力域系统及其控制方法,所述轮毂液压混合动力车辆动力域系统将中桥变速器电子控制系统TCU、液驱控制系统HCU、发动机管理系统EMS集成于动力域控制器,所述动力域控制器PDU通过信号输入模块采集CAN线、硬线信号输入,所述动力域控制器PDU通过控制输出模块向执行机构输出控制需求,所述动力域控制器通过整车端网关与其他域控制器进行通讯。本发明可替代原有分布式控制系统设计方案,弥补其对轮毂液压混合动力车辆多动力源与AMT的协调控制考虑的不足,提高车辆经济性、平顺性以及动力性等综合性能品质,且占用CAN网络资源少,开发费用较低,更易实现平台化。(The invention provides a power domain system of a hub hydraulic hybrid commercial vehicle and a control method thereof, wherein the power domain system of the hub hydraulic hybrid commercial vehicle integrates a middle axle transmission electronic control system (TCU), a hydraulic drive control system (HCU) and an Engine Management System (EMS) into a power domain controller, the power domain controller (PDU) collects CAN (controller area network) and hard wire signal input through a signal input module, the power domain controller (PDU) outputs control requirements to an actuating mechanism through a control output module, and the power domain controller communicates with other domain controllers through a finished vehicle end gateway. The invention CAN replace the original design scheme of a distributed control system, make up the deficiency of the coordinated control consideration of the multi-power source and the AMT of the hub hydraulic hybrid vehicle, improve the comprehensive performance quality of the vehicle such as economy, smoothness and dynamic property, and the like, occupy less CAN network resources, have lower development cost and are easier to realize the platformization.)

1. The utility model provides a wheel hub hydraulic pressure mixes dynamic commercial car power domain system which characterized in that, all integrates vehicle control unit, liquid drive control system, gearbox control system, engine management system in power domain controller, power domain controller exports the control demand to actuating mechanism through control output module, power domain controller communicates with other domain controllers through whole car end gateway, whole car end gateway with power domain controller passes through the ethernet and connects, power domain controller contains signal input function, control output function, vehicle mode arbitration function that traveles, energy management, torque distribution, dynamic coordination, engine control, clutch control, hydraulic pump control, gear shift control, valves control and failure diagnosis function.

2. The control method of the power domain system of the hub hydraulic hybrid commercial vehicle according to claim 1, characterized by comprising the following steps:

the method comprises the following steps that firstly, a dynamic domain dynamic model of the hub hydraulic hybrid commercial vehicle is built, the contents of the dynamic domain dynamic model building and model checking and correcting are mainly included, and further the building of the dynamic domain dynamic model of the hub hydraulic hybrid commercial vehicle provides a control-oriented model for the design of a subsequent control method;

aiming at the dynamic model building of the power domain in the step one, the building process is detailed: the method can be divided into a step (a), a step (b) and a step (c);

firstly, analyzing the coupling mechanism of each key component in a power domain to fully consider the coupling characteristics of each component; secondly, referring to the modeling principle of the AMEstim and TruckSim simulation platforms on each component to ensure the accuracy of the self-modeling dynamic response characteristics of each component;

step one (b), obtaining main constraint conditions of performance influence based on component modeling analysis, and completing establishment of a dynamic model of a power domain of the hub hydraulic hybrid vehicle by system dynamics analysis and combining a vehicle transmission theory to obtain an engine dynamics model, a liquid drive system dynamics model, a clutch dynamics model and a two-axis transmission dynamics model;

step one (c), the dynamic model of the power domain and the test result of the real vehicle test are subjected to benchmarking, the output result of the dynamic model of the power domain and the real vehicle data are subjected to regression analysis and comparison to obtain quantitative difference, so that the parameters of the dynamic model of the power domain are corrected, and repeated iteration convergence is carried out to obtain the high-precision dynamic model of the power domain;

step two, developing a power domain internal steady state control strategy of the wheel hub hydraulic hybrid commercial vehicle:

the steady-state control strategy in the power domain of the hub hydraulic hybrid commercial vehicle is developed in three parts step by step and specifically can be divided into a step two (a), a step two (b) and a step two (c);

step two (a), measuring and estimating working condition parameters and vehicle parameters, so that the vehicle model can accurately identify and judge the required road condition information and vehicle state information when driving under the established road condition;

step two (b), establishing a steady-state driving mode arbitration rule, determining a driving mode of the vehicle, solving according to the intention of a driver to obtain the required power of the vehicle, further controlling a traditional engine and a liquid drive system, completing power distribution to the traditional engine and the liquid drive system, ensuring that the synthesized torque of the vehicle reasonably follows the intention of the driver, and carrying out liquid charging and discharging on an energy accumulator through braking energy recovery to improve the economy of the vehicle;

step two (c), aiming at different driving modes, respectively solving a dynamic gear shifting rule and an economic gear shifting rule of the transmission, and further planning a target gear when the vehicle drives according to the vehicle speed and the pedal opening;

further, obtaining total steady state control variables of the hub hydraulic hybrid vehicle, including the required torque of the engine, the required torque of the hydraulic motor and the target gear of the two-shaft transmission;

further, the development of a steady-state control strategy in the power domain of the hub hydraulic hybrid commercial vehicle provides a following target for short-time domain dynamic control;

step three, designing a dynamic coordination control algorithm in the power domain of the hub hydraulic hybrid commercial vehicle, which can be specifically divided into a step three (a) and a step three (b):

step three (a), the smoothness influence brought by the switching of the driving mode is considered when the gear is not shifted, the smoothness influence is mainly concentrated in the transient process of the intervention and exit of the power of the liquid drive system or the engine, and then the dynamic coordination control in the power domain is carried out on the mode switching process;

step three (b), in the gear shifting process, because the clutch has the separation and combination process, the vehicle has power interruption, so the dynamic coordination control in the power domain is carried out on the gear shifting process; the separation of the clutch needs to carry out torque unloading processing on the engine, and at the moment, when the power of the vehicle is interrupted, a target value of the torque of the hydraulic motor needs to be reversely obtained according to the torque requirement of a driver by combining with the torque unloading dynamic process of the engine; meanwhile, after gear switching is completed and the clutch is combined, in order to quickly recover vehicle power and ensure that the loss of the clutch slip mode process is minimum, the engine needs to gradually increase the torque, and at the moment, the power domain controller needs to accurately observe the output torque of the clutch and combine the current torque required by a driver to obtain the torque compensation quantity of the hydraulic motor in the clutch combination process;

fourthly, carrying out integrated test and optimization aiming at the power domain system:

aiming at the integration test and optimization in the fourth step, the test and optimization process is refined: the method can be divided into a step four (a), a step four (b), a step four (c) and a step four (d);

integrating the power domain control strategies in the second step and the third step with the power domain dynamic model in the first step, and fully testing the whole vehicle control algorithm through system joint simulation under an offline condition;

establishing a hardware-in-loop simulation platform, and verifying the real-time performance of the power domain control strategy and algorithm by using a real controller;

fourthly (c), carrying out optimization calibration on the power domain control strategy, firstly extracting corresponding steady-state and dynamic optimization targets in the calibration process, further abstractively establishing corresponding value functions, obtaining a plurality of groups of calibration parameters through dispersion, substituting the calibration parameters into the power domain dynamic model to obtain corresponding performance values, and finally determining the optimal calibration parameters to be substituted into the power domain control strategy;

and step four (d), finally testing the actual performance of the power domain system of the hub hydraulic hybrid commercial vehicle through a real vehicle test, and further verifying the effectiveness and the practicability of the power domain control strategy.

Technical Field

The invention relates to the field of hybrid vehicle control, in particular to a power domain system of a hub hydraulic hybrid commercial vehicle and a control method thereof.

Background

With the development of new energy automobile technology, the hybrid electric vehicle can achieve good economy and emission performance of the whole automobile by means of improving the working efficiency of an engine, recycling regenerative braking energy and the like on the premise of meeting the power performance requirement of the whole automobile. Therefore, under the background of wide market demands, strict oil consumption limit and higher overall performance demands, the development of the high-efficiency commercial vehicle hybrid power system is an effective way for solving the problems, key technical research on the development process of the hybrid commercial vehicle is carried out, and the method has important significance for the industrial application of the hybrid commercial vehicle. The hydraulic hybrid power technology has the advantages of high power density, high energy charging and discharging speed, high energy recovery efficiency and the like, so that the heavy vehicle has strong competitiveness and good application prospect, and can be regarded as a feasible scheme for comprehensively solving the contradiction of the heavy commercial vehicle. For the wheel hub hydraulic hybrid vehicle, due to the fact that the structure of the wheel hub hydraulic hybrid vehicle is complex, a front wheel hydraulic drive system in a power system of the wheel hub hydraulic hybrid vehicle is timely coupled with power of a traditional engine, power domain integrated control of the wheel hub hydraulic hybrid commercial vehicle is difficult to achieve, and breakthrough of new theories and technologies is urgently needed. With the gradual emphasis on the vehicle function domain integrated control theory, today vehicle control is mainly distributed, and the future oriented by centralized control is spanned, the domain control integrated architecture taking a domain as a unit is a future trend, and research and breakthrough are urgently needed, so that the research on power domain control based on the hub hydraulic hybrid commercial vehicle has important practical significance for improving the competitiveness and continuous and stable development of the commercial vehicle in China.

In the prior art, most of the power domain system technologies are applied to pure electric vehicles or fuel cell vehicles, and few of the power domain system technologies are applied to hybrid vehicles, such as the invention patents disclosed in 2021, 2, 9: publication No.: CN112339574A, CN 112339574A; the invention patent disclosed in 12/11/2020: publication No.: CN112060926A, a power domain control system, a domain control system, and a fuel cell vehicle, the above inventions provide a power domain system architecture and a control method for a pure electric vehicle and a fuel cell vehicle, respectively, but the power coupling relationship between the pure electric vehicle and the fuel cell vehicle is simpler than that of a hybrid power, and the control of the power domain system and the coupling characteristics of the key power components are analyzed simply. Also for example, the invention patent disclosed in 2021, month 1, day 8: publication No.: CN112193182A, an integrated power domain control system and an automobile, the invention provides the integrated power domain control system and the automobile, and the leap from a plurality of controls to central integrated control is realized. The synchronous integration of software and hardware is realized, the size is greatly reduced, the cost is reduced, the device reusability is high, the reliability and the safety are greatly improved, and the energy consumption and the cost are reduced. However, the patent disclosed so far does not propose a method and a measure for controlling the power domain for the target characteristic of a hub hydraulic hybrid commercial vehicle.

Disclosure of Invention

In order to solve the defects of the prior art, the invention designs a power domain system of a hub hydraulic hybrid commercial vehicle and a control method thereof based on the hub hydraulic hybrid commercial vehicle, which can realize multi-target high-efficiency integration of each sub-controller in the power domain of the whole vehicle, further break through the control boundary of each sub-execution component, improve the defects of low communication efficiency, poor data transmission precision and redundant functions of wire harnesses and controllers in the traditional distributed control, provide an advantage platform foundation for comprehensive control optimization of multi-dimensional performance, fully play the redundant driving characteristics of the hub hydraulic hybrid power, realize coordinated stable control in the power domain, improve the comprehensive quality of the hybrid vehicle, and meet the requirements of users on consideration of gear shifting smoothness, driving economy and vehicle power.

In order to realize the purpose, the invention is realized by adopting the following technical scheme:

the power domain system of the wheel hub hydraulic hybrid commercial vehicle integrates a vehicle controller, a hydraulic drive control system, a gearbox control system and an engine management system in a power domain controller, the power domain controller outputs a control demand to an actuating mechanism through a control output module, the power domain controller communicates with other domain controllers through a vehicle end gateway, the vehicle end gateway is connected with the power domain controller through an Ethernet, the power domain controller comprises a signal input function, a control output function, a vehicle driving mode arbitration function, energy management, torque distribution, dynamic coordination, engine control, clutch control, hydraulic pump control, gear shift control, valve bank control and fault diagnosis function, and according to the power domain system of the wheel hub hydraulic hybrid commercial vehicle and the control method thereof, the power domain system comprises a power domain system control method, the method is characterized by comprising the following steps:

the method comprises the following steps that firstly, a dynamic domain dynamic model of the hub hydraulic hybrid commercial vehicle is built, the contents of the dynamic domain dynamic model building and model checking and correcting are mainly included, and further the building of the dynamic domain dynamic model of the hub hydraulic hybrid commercial vehicle provides a control-oriented model for the design of a subsequent control method;

aiming at the dynamic model building of the power domain in the step one, the building process is detailed: the method can be divided into a step (a), a step (b) and a step (c);

firstly, analyzing the coupling mechanism of each key component in a power domain to fully consider the coupling characteristics of each component; secondly, referring to the modeling principle of the AMEstim and TruckSim simulation platforms on each component to ensure the accuracy of the self-modeling dynamic response characteristics of each component;

step one (b), obtaining main constraint conditions of performance influence based on component modeling analysis, and completing establishment of a dynamic domain model of the hub hydraulic hybrid commercial vehicle by means of system dynamics analysis and combination of a vehicle transmission theory to obtain an engine dynamics model, a liquid drive system dynamics model, a clutch dynamics model and a two-shaft transmission dynamics model;

step one (c), the dynamic model of the power domain and the test result of the real vehicle test are subjected to benchmarking, the output result of the dynamic model of the power domain and the real vehicle data are subjected to regression analysis and comparison to obtain quantitative difference, so that the parameters of the dynamic model of the power domain are corrected, and repeated iteration convergence is carried out to obtain the high-precision dynamic model of the power domain;

step two, developing a power domain internal steady state control strategy of the wheel hub hydraulic hybrid commercial vehicle:

the steady-state control strategy in the power domain of the hub hydraulic hybrid commercial vehicle is developed in three parts step by step and specifically can be divided into a step two (a), a step two (b) and a step two (c);

step two (a), measuring and estimating working condition parameters and vehicle parameters, so that the vehicle model can accurately identify and judge the required road condition information and vehicle state information when driving under the established road condition;

step two (b), establishing a steady-state driving mode arbitration rule, determining a driving mode of the vehicle, solving according to the intention of a driver to obtain the required power of the vehicle, further controlling a traditional engine and a liquid drive system, completing power distribution to the traditional engine and the liquid drive system, ensuring that the synthesized torque of the vehicle reasonably follows the intention of the driver, and carrying out liquid charging and discharging on an energy accumulator through braking energy recovery to improve the economy of the vehicle;

step two (c), aiming at different driving modes, respectively solving a dynamic gear shifting rule and an economic gear shifting rule of the transmission, and further planning a target gear when the vehicle drives according to the vehicle speed and the pedal opening;

further, obtaining total steady state control variables of the hub hydraulic hybrid commercial vehicle, wherein the total steady state control variables comprise the required torque of the engine, the required torque of the hydraulic motor and the target gear of the two-shaft transmission;

further, the development of a steady-state control strategy in the power domain of the hub hydraulic hybrid commercial vehicle provides a following target for short-time domain dynamic control;

step three, designing a dynamic coordination control algorithm in the power domain of the hub hydraulic hybrid commercial vehicle, which can be specifically divided into a step three (a) and a step three (b):

step three (a), the smoothness influence brought by the switching of the driving mode is considered when the gear is not shifted, the smoothness influence is mainly concentrated in the transient process of the intervention and exit of the power of the liquid drive system or the engine, and then the dynamic coordination control in the power domain is carried out on the mode switching process;

step three (b), in the gear shifting process, because the clutch has the separation and combination process, the vehicle has power interruption, so the dynamic coordination control in the power domain is carried out on the gear shifting process; the separation of the clutch needs to carry out torque unloading processing on the engine, and at the moment, when the power of the vehicle is interrupted, a target value of the torque of the hydraulic motor needs to be reversely obtained according to the torque requirement of a driver by combining with the torque unloading dynamic process of the engine; meanwhile, after gear switching is completed and the clutch is combined, in order to quickly recover vehicle power and ensure that the loss of the clutch slip mode process is minimum, the engine needs to gradually increase the torque, and at the moment, the power domain controller needs to accurately observe the output torque of the clutch and combine the current torque required by a driver to obtain the torque compensation quantity of the hydraulic motor in the clutch combination process;

fourthly, carrying out integrated test and optimization aiming at the power domain system:

aiming at the integration test and optimization in the fourth step, the test and optimization process is refined: the method can be divided into a step four (a), a step four (b), a step four (c) and a step four (d);

integrating the power domain control strategies in the second step and the third step with the power domain dynamic model in the first step, and fully testing the whole vehicle control algorithm through system joint simulation under an offline condition;

establishing a hardware-in-loop simulation platform, and verifying the real-time performance of the power domain control strategy and algorithm by using a real controller;

fourthly (c), carrying out optimization calibration on the power domain control strategy, firstly extracting corresponding steady-state and dynamic optimization targets in the calibration process, further abstractively establishing corresponding value functions, obtaining a plurality of groups of calibration parameters through dispersion, substituting the calibration parameters into the power domain dynamic model to obtain corresponding performance values, and finally determining the optimal calibration parameters to be substituted into the power domain control strategy;

and step four (d), finally testing the actual performance of the power domain system of the hub hydraulic hybrid commercial vehicle through a real vehicle test, and further verifying the effectiveness and the practicability of the power domain control strategy.

Compared with the prior art, the invention has the following beneficial effects:

1. the power domain system of the hub hydraulic hybrid commercial vehicle and the control method thereof can realize multi-target high-efficiency integration of each sub-controller in the power domain of the whole vehicle, further break through the control boundary of each sub-execution component, and improve the defects of low communication efficiency, poor data transmission precision, redundant functions of wire harnesses and controllers and the like of the traditional distributed control;

2. the power domain system of the wheel hub hydraulic hybrid commercial vehicle and the control method thereof adopt a centralized power domain control framework, so that an advantage platform foundation is provided for comprehensive control optimization of multi-dimensional performance, and the redundant driving characteristics of the wheel hub hydraulic hybrid power can be fully exerted;

3. the power domain system of the wheel hub hydraulic hybrid commercial vehicle and the control method thereof can realize the coordinated stable control in the power domain of the wheel hub hydraulic hybrid vehicle, improve the comprehensive quality of the hybrid vehicle, and further can meet the requirements of a user on the gear shifting smoothness, the driving economy and the vehicle power.

Drawings

The following description of the embodiments will be readily understood in conjunction with the accompanying drawings, in which:

FIG. 1 is a schematic structural diagram of a power domain system of a hub hydraulic hybrid commercial vehicle according to an embodiment of the invention;

FIG. 2 is a schematic diagram of a power domain system of a hub hydraulic hybrid commercial vehicle according to an embodiment of the present invention;

FIG. 3 is a functional schematic diagram of a power domain controller of a hub hydraulic hybrid commercial vehicle according to an embodiment of the invention;

fig. 4 is a schematic diagram of a control method and a control flow of a power domain system of a hub hydraulic hybrid commercial vehicle according to an embodiment of the invention.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.

A power domain system of a hub hydraulic hybrid commercial vehicle and a control method thereof will be described below with reference to the accompanying drawings, but the present invention is not limited to these embodiments.

Referring to fig. 1, the hub hydraulic hybrid vehicle mainly includes the following components and assemblies: the system comprises a front axle wheel, a 2-hub hydraulic motor, a 3-energy accumulator, a 4-power domain controller, a 5-middle axle wheel, a 6-rear axle wheel, a 7-main reducer and differential assembly, an 8-universal joint, a 9-12 gear AMT assembly, a 10-power takeoff, an 11-engine assembly, a 12-hydraulic variable pump and a 13-hydraulic combination valve assembly. The power domain system of the hub hydraulic hybrid vehicle integrates a vehicle controller, a hydraulic drive control system, a gearbox control system and an engine management system in the power domain controller.

Referring to fig. 2, the power domain controller includes a signal input function, a control output function, a vehicle driving mode arbitration function, energy management, torque distribution, dynamic coordination, engine control, clutch control, hydraulic pump control, shift control, valve bank control, and a fault diagnosis function.

Referring to fig. 3, the power domain controller collects the signal input of the CAN line and the hard line through the signal input module; the power domain controller outputs a control demand to the actuating mechanism through the control output module; the power domain controller is communicated with other domain controllers through a whole vehicle end gateway, and the whole vehicle end gateway is connected with the power domain controller through the Ethernet.

Referring to the attached figure 4, the power domain system of the hub hydraulic hybrid commercial vehicle and the control method thereof according to the invention comprise the following control methods:

step one, establishing a dynamic model of a power domain of the hub hydraulic hybrid vehicle, wherein the dynamic model mainly comprises two parts of establishment of the dynamic model of the power domain and verification and correction of the model, and further the establishment of the dynamic model of the power domain of the hub hydraulic hybrid vehicle provides a control-oriented model for the design of a subsequent control method;

aiming at the dynamic model building of the power domain in the step one, the building process is detailed: the method can be divided into a step (a), a step (b) and a step (c);

firstly, analyzing the coupling mechanism of each key component in a power domain to fully consider the coupling characteristics of each component; secondly, referring to the modeling principle of the AMEstim and TruckSim simulation platforms on each component to ensure the accuracy of the self-modeling dynamic response characteristics of each component;

step one (b), obtaining main constraint conditions of performance influence based on component modeling analysis, and completing establishment of a dynamic model of a power domain of the hub hydraulic hybrid vehicle by system dynamics analysis and combining a vehicle transmission theory to obtain an engine dynamics model, a liquid drive system dynamics model, a clutch dynamics model and a two-axis transmission dynamics model;

step one (c), the dynamic model of the power domain and the test result of the real vehicle test are subjected to benchmarking, the output result of the dynamic model of the power domain and the real vehicle data are subjected to regression analysis and comparison to obtain quantitative difference, so that the parameters of the dynamic model of the power domain are corrected, and repeated iteration convergence is carried out to obtain the high-precision dynamic model of the power domain;

step two, developing a steady-state control strategy in the power domain of the hub hydraulic hybrid vehicle:

the steady-state control strategy in the power domain of the hub hydraulic hybrid commercial vehicle is developed in three parts step by step and specifically can be divided into a step two (a), a step two (b) and a step two (c);

step two (a), measuring and estimating working condition parameters and vehicle parameters, so that the vehicle model can accurately identify and judge the required road condition information and vehicle state information when driving under the established road condition;

step two (b), establishing a steady-state driving mode arbitration rule, determining a driving mode of the vehicle, solving according to the intention of a driver to obtain the required power of the vehicle, further controlling a traditional engine and a liquid drive system, completing power distribution to the traditional engine and the liquid drive system, ensuring that the synthesized torque of the vehicle reasonably follows the intention of the driver, and carrying out liquid charging and discharging on an energy accumulator through braking energy recovery to improve the economy of the vehicle;

step two (c), aiming at different driving modes, respectively solving a dynamic gear shifting rule and an economic gear shifting rule of the transmission, and further planning a target gear when the vehicle drives according to the vehicle speed and the pedal opening;

further, obtaining total steady state control variables of the hub hydraulic hybrid commercial vehicle, wherein the total steady state control variables comprise the required torque of the engine, the required torque of the hydraulic motor and the target gear of the two-shaft transmission;

further, the development of a steady-state control strategy in the power domain of the hub hydraulic hybrid commercial vehicle provides a following target for short-time domain dynamic control;

step three, designing a dynamic coordination control algorithm in the power domain of the hub hydraulic hybrid commercial vehicle, which can be specifically divided into a step three (a) and a step three (b):

step three (a), the smoothness influence brought by the switching of the driving mode is considered when the gear is not shifted, the smoothness influence is mainly concentrated in the transient process of the intervention and exit of the power of the liquid drive system or the engine, and then the dynamic coordination control in the power domain is carried out on the mode switching process;

step three (b), in the gear shifting process, because the clutch has the separation and combination process, the vehicle has power interruption, so the dynamic coordination control in the power domain is carried out on the gear shifting process; the separation of the clutch needs to carry out torque unloading processing on the engine, and at the moment, when the power of the vehicle is interrupted, a target value of the torque of the hydraulic motor needs to be reversely obtained according to the torque requirement of a driver by combining with the torque unloading dynamic process of the engine; meanwhile, after gear switching is completed and the clutch is combined, in order to quickly recover vehicle power and ensure that the loss of the clutch slip mode process is minimum, the engine needs to gradually increase the torque, and at the moment, the power domain controller needs to accurately observe the output torque of the clutch and combine the current torque required by a driver to obtain the torque compensation quantity of the hydraulic motor in the clutch combination process;

fourthly, carrying out integrated test and optimization aiming at the power domain system:

aiming at the integration test and optimization in the fourth step, the test and optimization process is refined: the method can be divided into a step four (a), a step four (b), a step four (c) and a step four (d);

integrating the power domain control strategies in the second step and the third step with the power domain dynamic model in the first step, and fully testing the whole vehicle control algorithm through system joint simulation under an offline condition;

establishing a hardware-in-loop simulation platform, and verifying the real-time performance of the power domain control strategy and algorithm by using a real controller;

fourthly (c), carrying out optimization calibration on the power domain control strategy, firstly extracting corresponding steady-state and dynamic optimization targets in the calibration process, further abstractively establishing corresponding value functions, obtaining a plurality of groups of calibration parameters through dispersion, substituting the calibration parameters into the power domain dynamic model to obtain corresponding performance values, and finally determining the optimal calibration parameters to be substituted into the power domain control strategy;

and step four (d), finally testing the actual performance of the power domain system of the hub hydraulic hybrid commercial vehicle through a real vehicle test, and further verifying the effectiveness and the practicability of the power domain control strategy.