A model library construction method for VCU control system of unmanned vehicle based on Modelica

Abstract

The present application discloses a method for constructing a model library of a driverless car VCU control system based on Modelica, the method comprising: determining the vehicle parameters of the driverless car and the corresponding vehicle control schematic diagram of the VCU control system, and dividing the functional requirements of the VCU control system to determine the functional modules; determining the correspondence between the input signal and the actual output control signal under different driving states, and establishing a logic judgment module based on the correspondence and the preset electrical signal interface module; establishing a signal interface based on the functional requirements of the VCU control system, connecting the signal interface with the logic judgment module, and establishing a functional module model of the functional module; according to the vehicle control schematic diagram, connecting the functional module models in sequence and performing closed-loop simulation tests to adjust the functional module models. Through the technical solution in the present application, the problems of incomplete configuration of basic vehicle parameters and missing vehicle interface functions in the VCU control system modeling in the related technology are solved.

Description

Technical Field

[0001] The present application relates to the technical field of vehicle simulation modeling, and in particular to a method for constructing a model library of a VCU control system of an unmanned vehicle based on Modelica. Background Art

[0002] Simulation technology is a general technology that is applied in many fields. Through the combination of computer systems and physical equipment, it greatly improves the efficiency of various production and research and development work. It has the characteristics of strong professionalism, wide range and comprehensiveness. As the foundation of simulation technology, modeling technology and modeling methods have greatly influenced the development of simulation technology. From model establishment to result verification to model application, the interaction and reuse of various models are more critical, and modeling occupies an increasingly important position in simulation technology.

[0003] In the prior art, based on the currently commonly used unmanned vehicle control unit (VCU) control system simulation modeling method, the interactivity and reusability of the unmanned vehicle VCU control system basic model have not been taken seriously; and the category of the model is not clear, resulting in the current unmanned vehicle VCU control system simulation modeling efficiency is low, the coverage is small, and it takes a long time from modeling to verification.

[0004] In addition, the functional definition of the VCU control system is not clear, and the functional management method is complicated and unclear. It is difficult to add and delete functions of the VCU control system in actual modeling. Problems such as missing interfaces and incomplete parameters often occur, resulting in many errors in actual vehicle operation, which greatly affects the modeling efficiency of the VCU control system. Summary of the invention

[0005] The purpose of this application is to define the functions of the VCU control system of an unmanned vehicle and decompose the model of the entire VCU control system to solve the problems of incomplete configuration of basic vehicle parameters and missing vehicle interface functions in the modeling of the VCU control system in related technologies, ensure the accuracy of VCU control system modeling, and provide model reusability.

[0006] The technical solution of the present application is: to provide a model library construction method for a VCU control system of an unmanned vehicle based on Modelica, the method comprising: step 1, determining the vehicle parameters of the unmanned vehicle and the corresponding vehicle control schematic diagram of the VCU control system, and dividing the functional requirements of the VCU control system according to the vehicle control schematic diagram to determine the functional modules; step 2, determining the corresponding relationship between the input signal and the actual output control signal under different driving states of the unmanned vehicle, and combining the basic judgment module according to the corresponding relationship and the preset electrical signal interface module to establish a logic judgment module, wherein the input signal is the signal collected by the vehicle sensor and input to the VCU control system, and the actual output control signal is the actual control signal for switching between different driving states; step 3, establishing a signal interface according to the functional requirements of the VCU control system, connecting the signal interface with the corresponding logic judgment module, and establishing a functional module model of the functional module; step 4, according to the vehicle control schematic diagram, connecting the functional module models in sequence and performing closed-loop simulation tests to obtain the actual vehicle state control results, and comparing the actual vehicle state control results with the expected results to adjust the functional module models.

[0007] In any of the above technical solutions, further, step 1 specifically includes: step 11, determining the vehicle parameters, wherein the vehicle parameters include at least vehicle performance parameters and vehicle power parameters; step 12, determining the vehicle control schematic diagram of the VCU control system based on the vehicle parameters; step 13, determining the signal interface requirements of the VCU control system based on the vehicle control schematic diagram; step 14, dividing the functional requirements of the VCU control system according to the signal interface requirements and the vehicle control schematic diagram, and determining the functional modules.

[0008] In any of the above technical solutions, further, the functional modules at least include: a motor controller module, an energy management module, a vehicle command module, a state machine module, a relay management module and a system control monitoring module.

[0009] In any of the above technical solutions, further, in step 3, the function module modeling process of the state machine module specifically includes: step 301, defining the upper state of the state machine module and the lower state included in the upper state, defining the number of input and output signal interfaces required by the state machine module, and establishing empty state modules with only input and output signal interfaces corresponding to the lower state one by one according to the preset electrical signal interface module, wherein the upper state includes at least an initial state, an intermediate state, and a terminal state; step 302, adding the corresponding logic judgment module to the empty state module, and connecting the interface of the empty state module with the logic judgment module in turn, Establish a model of the underlying state; step 303, classify the corresponding underlying state model according to the initial state, the terminal state and the corresponding underlying state, and connect them through a preset electrical signal interface module to generate a model of the initial state and a model of the terminal state; step 304, add the corresponding logic judgment module and the underlying state model according to the trigger event requirements of the vehicle state change to generate a model of the intermediate state; step 305, connect the initial state model, the terminal state model and the intermediate state model through the corresponding preset electrical signal interface module to generate a functional module model of the state machine module.

[0010] In any of the above technical solutions, further, in step 3, the functional module modeling process of the energy management module specifically includes: step 311, using the preset electrical signal interface module as the input and output interface to establish a blank energy management module and a blank energy distribution strategy logic control module; step 312, establishing a battery SOC estimation module based on the modified ampere-hour integration method, and establishing an energy distribution module according to the requirements of each output interface through the fuzzy logic control method; step 313, filling the SOC estimation module and the energy distribution module into the blank energy distribution strategy logic control module, and connecting the corresponding signal interface to generate a whole vehicle energy distribution strategy module; step 314, adding the corresponding logic model between the input interface of the blank energy management module and the whole vehicle energy distribution strategy module to establish a complete energy management module.

[0011] The beneficial effects of this application are:

[0012] The technical solution in the present application separates the realization of different control functions of the VCU control system through a logic judgment module established based on Modelica software and pre-defined vehicle control function requirements and vehicle parameters, and connects them with corresponding signal interfaces, thereby reducing the number of interfaces, the possibility of function omission or loss in the modeling process of the whole vehicle VCU control system, solving the problems of unequal number of channels and incomplete configuration of basic vehicle parameters, greatly increasing the accuracy of the model, and performing hierarchical modeling of the VCU control system, which can also greatly improve the iterative effect of the model closed-loop test and improve the model interoperability and reusability. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The advantages of the above and / or additional aspects of the present application will become apparent and easily understood in the description of the embodiments in conjunction with the following drawings, in which:

[0014] Figure 1 is a schematic flow chart of a method for constructing a model library of a VCU control system of an unmanned vehicle based on Modelica according to an embodiment of the present application;

[0015] Figure 2 is a schematic diagram of a VCU control system according to an embodiment of the present application;

[0016] Figure 3 is a schematic diagram of state machine modeling according to an embodiment of the present application;

[0017] Figure 4 It is a schematic diagram of VCU control system modeling according to an embodiment of the present application. DETAILED DESCRIPTION

[0018] In order to more clearly understand the above-mentioned purposes, features and advantages of the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0019] In the following description, many specific details are elaborated to facilitate a full understanding of the present application. However, the present application may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present application is not limited to the specific embodiments disclosed below.

[0020] like Figure 1 As shown, this embodiment provides a method for constructing a model library of a VCU control system of an unmanned vehicle based on Modelica, including:

[0021] Step 1: determine the vehicle parameters of the driverless car and the corresponding vehicle control schematic diagram of the VCU control system, and divide the functional requirements of the VCU control system according to the vehicle control schematic diagram to determine the functional modules;

[0022] Furthermore, step 1 specifically includes:

[0023] Step 11, determining vehicle parameters, wherein the vehicle parameters at least include vehicle performance parameters and vehicle power parameters;

[0024] In this embodiment, the vehicle parameters of the driverless car include at least:

[0025] A) Vehicle performance parameters: curb weight, fully loaded mass, main drive ratio, main drive efficiency, gearbox, tire rolling radius, rolling friction coefficient, frontal area, drag coefficient;

[0026] B) Vehicle dynamic parameters: maximum speed, economic speed, acceleration performance, maximum climbing grade, maximum climbing speed, continuous climbing grade, continuous climbing speed, and vehicle range.

[0027] Step 12, determining the vehicle control schematic diagram of the VCU control system according to the vehicle parameters;

[0028] Specifically, by defining the vehicle parameters, draw the corresponding vehicle control schematic diagram, including vehicle wiring harness layout, electrical distribution, power distribution, electrical interface connection, etc.;

[0029] Taking the maximum speed and economic speed of the vehicle as an example, first determine the specific relevant electrical parameters of the motor controller such as voltage, current, power, etc., draw the power distribution diagram and ground distribution diagram, and then collect the corresponding interface information for vehicle speed control connected to the motor controller and the VCU control system, including the plug-in model, hole position information, and hole position function, and then draw the following diagram: Figure 1 Just fill in the corresponding hole number and hole information as shown in the box diagram.

[0030] Step 13: Determine the signal interface requirements of the VCU control system according to the vehicle control schematic diagram;

[0031] Taking the front and rear wheel speed control function as an example, the signal interface requirements can be determined through the interface definition information on the vehicle control schematic diagram. Figure 2 As shown, it can be seen that if the wheel speed needs to be controlled, the signal interface requirements as shown in the figure are required.

[0032] In this embodiment, the VCU control system receives and transmits numerous signals, involving a series of signal controls such as communication interface, working voltage, sensor power supply, analog input, analog output, switch input, frequency input, analog output, PWM output, etc., and different signals correspond to different functional requirements. For example, the working voltage signals of different electrical components correspond to the energy distribution function of the battery, and the input and output of the analog quantities of relay signals such as DCDC, IG1, IG2 correspond to the vehicle status judgment function, etc., thereby determining the corresponding functions of the VCU control system according to the requirements of different vehicle signal interfaces.

[0033] Step 14: According to the signal interface requirements and the vehicle control schematic diagram, the functional requirements of the VCU control system are divided and the functional modules are determined.

[0034] Specifically, according to the determined vehicle control schematic diagram and the signal interface requirements in the previous step, determine the functional requirements of the VCU control system. The VCU functional requirements include:

[0035] Vehicle speed control, energy distribution management, communication network management, working mode control, vehicle electrical appliance management, fault diagnosis and processing, system status instrument display, vehicle equipment management, vehicle system control and other functions.

[0036] According to these functional requirements, the VCU control system model can be decomposed into motor controller module, energy management module, vehicle command module, state machine module, relay management module, and system control monitoring module.

[0037] The motor controller module includes a brake module, a steering module, an acceleration module, a constant speed module, a reverse module, and a parking module. The motor controller module can reasonably control the working state and power output of the motor according to different instructions issued by the vehicle to meet the driving conditions.

[0038] The energy management module includes the battery SOC module, battery current module, battery management system module, vehicle-mounted energy-consuming component management module, and charging module. The energy management module is used to coordinate and manage various electrical equipment to ensure the energy utilization rate of the vehicle.

[0039] The state machine module includes a signal diagnosis module and a fault processing module. By receiving changes in various signals such as radar signals, image signals, current and voltage signal lights, the state machine module diagnoses the vehicle status in real time based on the built-in judgment logic and issues corresponding control instructions.

[0040] The vehicle command module includes modules such as vehicle speed, vehicle steering wheel angle, vehicle heading angle change rate, accelerator pedal opening, brake pedal opening, etc. The vehicle command module communicates reliably with the motor, DC / DC, nickel-hydrogen battery pack, etc., and outputs corresponding control instructions to the corresponding controller to control the vehicle operation;

[0041] The relay management module includes input undervoltage protection module, input overvoltage protection module, output short circuit protection module, output current limiting protection module, output anti-backflow module, overheating module, external work enable module, etc. The relay management module is used to convert high-voltage direct current into low-voltage direct current to provide power supply for vehicle-mounted equipment.

[0042] The system control and monitoring module includes SOC monitoring module, power voltage and current monitoring module, vehicle mode monitoring module, vehicle speed monitoring module, vehicle fault monitoring module, vehicle surrounding environment monitoring module, vehicle GPS position signal monitoring module, etc. The system control and monitoring module is responsible for real-time monitoring of the data of each system of the entire vehicle.

[0043] Step 2, determining the correspondence between the input signal and the actual output control signal under different driving states of the driverless car, and combining the basic judgment module according to the correspondence and the preset electrical signal interface module to establish a logic judgment module, wherein the input signal is the signal collected by the vehicle sensor and input to the VCU control system, and the actual output control signal is the actual control signal for switching between different driving states;

[0044] Specifically, the logic judgment module refers to a module that outputs a specific output signal / data for one or more outputs according to pre-defined judgment conditions by judging the current state.

[0045] There are basic judgment modules in the Modelica simulation software, but since the actual VCU control of unmanned vehicles requires identification and judgment of multiple variables under different conditions, it is necessary to combine the basic judgment modules and change the judgment conditions to obtain modeling elements suitable for the VCU control system. Among them, the basic judgment modules include OR, AND, XOR, NOR, NAND, XNOR and other judgment modules.

[0046] The unmanned vehicle VCU control system directly transmits the vehicle's control instructions by transmitting signals whose amplitude changes over time, and transmits vehicle instructions in combination with the electrical signal interface module preset by the software.

[0047] In this embodiment, the driving status of the unmanned vehicle includes different states such as charging, starting, acceleration, constant speed, deceleration, and parking. By using vehicle sensors, data input to the VCU control system for judgment under different driving states can be collected and used as input signals of the logic judgment module, which correspond to the actual output control signals required for the current driving state change of the vehicle. Based on the correspondence between these input signals and the actual output control signals, the input and output and judgment conditions required by all logic judgment modules are sorted out.

[0048] Afterwards, according to each sorted out judgment condition (corresponding relationship), the basic judgment module and the preset electrical signal interface module are added between the corresponding input and output, so as to establish all the logical judgment modules required by the VCU control system.

[0049] Taking the vehicle parking charging preparation state as an example, it is necessary to establish a logic judgment module to determine whether the vehicle is in the parking state and has completed charging preparation. The judgment condition of this module is whether each relay analog input signal and DCDC analog input signal are open or closed, so the specific modeling process is as follows:

[0050] 1. The input and output ports of the module are established through the preset electrical signal interface module. The input ports are three relay signals MainCount, IG1Count, IG2Count and one DCDC controller signal DcdcCount. The output port is the module's judgment result signal Prepare_Complete on whether the vehicle has reached the parking charging preparation state;

[0051] 2. Determine the judgment logic of the module. In the first step, when the DCDC relay signal is disconnected and the disconnection reaches 0.05s, the intermediate variable A=true is output, and the basic judgment module AND, that is, DcdcCount=0AND time>0.05 is used to complete it; in the second step, when the main relay signal is disconnected and the disconnection reaches 0.05s, the intermediate variable B=true is output, and the basic judgment module AND, that is, MainCount=0AND time>0.05 is used to complete it; in the third step, when one or more pre-charging relays are closed and the closing reaches 0.05s, the intermediate variable C=true is output, and the basic judgment modules AND, OR, that is, (IG1Count=1ANDtime>0.05)OR(IG1Count=1AND time>0.05) are used to complete it; in the fourth step, when the judgment conditions of the previous three steps are met at the same time, the output reaches the vehicle parking charging preparation state signal Prepare_Complete=1, and the basic judgment module AND, that is, A=true AND B=true AND C=true is used to complete it;

[0052] 3. Connect each judgment condition module established in the second step to the input and output ports of the first step, thus completing the establishment of a logic judgment module.

[0053] Step 3: Establish a signal interface according to the functional requirements of the VCU control system, connect the signal interface with the corresponding logic judgment module, and establish a functional module model of the functional module;

[0054] Specifically, the VCU control system of an unmanned vehicle is essentially a process from detection to judgment and finally to realization of all functional requirements involved in the process from starting to parking, that is, monitoring, diagnosis and management of the real-time status of the vehicle. VCU control system modeling is to decompose this process step by step, divide the VCU control system into modules through defined different functional requirements, and then establish the signal interfaces required by the corresponding functions for the divided modules in turn, and finally connect the logical judgment modules with different functions established in advance with the corresponding signal interfaces to complete the establishment of all VCU functional modules.

[0055] In this embodiment, based on the real-time control requirements of the vehicle's entire operating status, the vehicle's operating status logic is established, and based on the logic judgment module and the operating status logic, a corresponding VCU state machine module is established.

[0056] In this embodiment, according to the definition of vehicle parameters, the number of interfaces and the number of interface channels in the vehicle control schematic diagram are determined, and based on the logical judgment module and the mathematical calculation interface preset in the Modelica software, a vehicle command module is established, and the vehicle command module is connected to the state machine module based on the preset electrical interface module to receive the judgment result of the state machine module on the sensor data, thereby realizing the preset function of the vehicle command module.

[0057] In this embodiment, according to the vehicle relay switch requirements in the vehicle control schematic diagram, a relay management module is established based on the logic judgment module.

[0058] In this embodiment, by defining the motor states under the parking, braking, acceleration and deceleration behaviors of the vehicle, a motor controller module is established based on the logic judgment module;

[0059] In this embodiment, by defining the output power change requirements of the power battery and the energy distribution requirements of the vehicle electrical components under the parking, braking, acceleration and deceleration behaviors of the vehicle, an energy management module is established based on the logic judgment module and the mathematical calculation module preset by the Modelica software;

[0060] In this embodiment, the system control and monitoring module is used to receive in real time all signals transmitted by sensors arranged on the vehicle body and circulating signals within the VCU control system itself. The total number of interfaces of the system control and monitoring module needs to be defined through the number and functions of sub-modules that have been determined, wherein the interface at least includes power input, analog input, analog output, high-side switch quantity acquisition, low-side switch quantity acquisition, low-side drive output, high-side drive output, pulse / frequency output, temperature signal output, etc., and corresponding SOC monitoring, voltage and current monitoring and other sub-modules are established one by one through the preset electrical signal interface module. Finally, all sub-modules are connected through the preset electrical signal interface module to complete the modeling of the functional module model of the system control and monitoring module of the VCU control system.

[0061] like Figure 3 As shown, in a preferred implementation of this embodiment, the function module modeling process of the state machine module specifically includes:

[0062] Step 301, define the upper state of the state machine module and the lower state included in the upper state, define the number of input and output signal interfaces required by the state machine module, and establish empty state modules with only input and output signal interfaces corresponding to the lower state one by one according to the preset electrical signal interface modules, wherein the upper state includes at least an initial state, an intermediate state, and a terminal state;

[0063] Specifically, the state module is divided into three upper states: initial state, intermediate state, and terminal state; the initial state includes the following underlying states: charging preparation state, charging state, charging completion state, vehicle start preparation state, vehicle stationary state; the intermediate state includes the following underlying states: vehicle acceleration state, vehicle constant speed state, vehicle deceleration state; the terminal state includes the following underlying states: vehicle parking preparation state, vehicle parking completion state.

[0064] Then, according to all the defined underlying states, the corresponding empty state modules with only input and output signal interfaces are established one by one using the electrical signal interface modules preset by the Modelica software.

[0065] Step 302, add the corresponding logic judgment module to the empty state module, and connect the interface of the empty state module with the logic judgment module in sequence to establish a model of the bottom state;

[0066] Specifically, after all the underlying empty state modules are established, the logic judgment module of the corresponding state established in step 2 is added to the underlying empty state module, and then the input and output interfaces of the underlying state modules are connected through the preset electrical signal interface module to complete the modeling of all independent underlying state modules.

[0067] Taking the charging preparation state as an example, a logic judgment module is added to the charging preparation state module, wherein the MainCount, IG1Count, and IG2Count interfaces of the logic judgment module are connected to the input interface of the charging preparation state module, and the Prepare_Complet interface of the logic judgment module is connected to the output interface of the charging preparation state module.

[0068] Step 303, classifying the models of the bottom state according to the initial state, the final state and the corresponding bottom state, and connecting them through a preset electrical signal interface module to generate a model of the initial state and a model of the final state;

[0069] Specifically, all independent bottom-level state modules are added to the corresponding initial state and terminal state according to the above classification, and connected through the electrical signal interface module preset by the software to complete the modeling of the two upper-level states.

[0070] Taking vehicle charging as an example, the Prepare_Complet output interface of the charging preparation state module is connected to the input interface of the charging state module, and the output interface of the charging state module is connected to the input interface of the charging completion state module.

[0071] Step 304, adding corresponding logic judgment modules and models of underlying states according to the triggering event requirements of vehicle state changes to generate a model of intermediate states;

[0072] Specifically, the acceleration, deceleration, and constant speed driving state changes of the driverless vehicle are achieved through the automatic change of the intermediate state of the vehicle. Therefore, the corresponding logic judgment module built in step 2 should be added to the internal conversion between the corresponding intermediate states according to the trigger event requirements of the vehicle state change, so as to complete the modeling of the entire intermediate state.

[0073] Step 305 , the model of the initial state, the model of the final state, and the model of the intermediate state are connected through corresponding preset electrical signal interface modules to generate a functional module model of the state machine module.

[0074] Specifically, the initial state, intermediate state, and terminal state are connected through a preset electrical signal interface module to form a closed loop, completing the modeling of the entire state machine. Among them, the vehicle's initial state module needs to be responsible for the function of data interaction between the entire state machine and other VCU control system functional modules.

[0075] In this embodiment, the data transmitted by the system control monitoring module through the preset electrical signal interface module is the entry action, and the data output by the state machine module to the subsequent instruction module is the exit action. After the closed-loop operation of the entire state machine, the corresponding state instruction is output to complete the processing of the VCU control system state machine data.

[0076] In this embodiment, the number of electrical signal input interfaces of the vehicle command module is determined by the number of data transmitted by the state machine module, the number of electrical signal output interfaces of the vehicle command module is determined by the vehicle control schematic diagram, and the corresponding logic judgment module is added to the middle of the corresponding input and output interfaces, and the corresponding instruction issuing submodule (vehicle speed, turning angle, power supply) is established, and all instruction issuing submodules are connected through electrical signals to establish a vehicle command module, and the work of issuing instructions after the state machine converts the vehicle state is completed;

[0077] In another preferred implementation of this embodiment, the function module modeling process of the energy management module specifically includes:

[0078] Step 311, using the preset electrical signal interface module as the input and output interface, establish a blank energy management module and a blank energy allocation strategy logic control module.

[0079] Step 312, establishing a battery SOC estimation module based on the modified ampere-hour integration method, and establishing an energy distribution module according to the requirements of each output interface through a fuzzy logic control method.

[0080] In this embodiment, the calculation formula corresponding to the ampere-hour integration method is:

[0081]

[0082] Where SOC0 is the initial SOC; c is the maximum capacity at different temperatures; η is the average coulombic efficiency at different temperatures; I is the instantaneous current.

[0083] The basic mathematical model preset by Modelica software is used to establish the battery SOC estimation module, and then the energy required by each electrical device is determined according to the power supply parameters of the electrical device. The basic mathematical module preset by Modelica software is used to establish the energy distribution module according to the requirements of each output interface through the fuzzy logic control method. The calculation formula of the fuzzy logic control modeling principle is:

[0084]

[0085] Where a, b, c, d are the segmentation points corresponding to the multi-segment function, x is a continuous or discrete variable, and y is a continuous or discrete control value.

[0086] Step 313, fill the SOC estimation module and the energy distribution module into the blank energy distribution strategy logic control module, and connect the corresponding signal interface to generate a whole vehicle energy distribution strategy module, wherein the management strategy in the whole vehicle energy distribution strategy module includes the management strategies for battery charging status, discharging status, SOC insufficient status, etc.

[0087] Step 314, adding the corresponding logic model between the input interface of the blank energy management module and the vehicle energy distribution strategy module, establishing a complete energy management module, and outputting the battery control strategy;

[0088] In this embodiment, the modeling of the relay management module and the motor controller module is similar to the above process, and the corresponding relay control strategy and motor control strategy are output, which will not be repeated here.

[0089] Based on the electrical interface module, the relay management module, the motor controller module, the energy management module are connected to the vehicle command module to execute the vehicle status command in real time, and based on the signal transmission interface, they are connected to the system control monitoring module to feedback the executed vehicle command status.

[0090] Step 4: According to the vehicle control schematic diagram, connect the functional module models in sequence and perform closed-loop simulation tests to obtain the actual vehicle state control results, and compare the actual vehicle state control results with the expected results to adjust the functional module models.

[0091] Specifically, the simulation verification of the VCU control system is not only a verification process for the correctness and model error of a model, but also a verification process for the efficiency and practicality of the modeling method. The VCU control system modeling method that defines vehicle parameters and interface requirements and then performs functional decomposition significantly reduces the error problem caused by missing model signals while ensuring modeling efficiency, thus ensuring modeling accuracy.

[0092] Based on the vehicle function definition and the number of vehicle control interfaces, determine the number of vehicle sensors, and establish a system control monitoring module based on the mathematical calculation module preset by the Modelica software to process the data transmitted by the sensors, and connect the signal transmission interface module with the state machine module to transmit the processed vehicle data;

[0093] Integrate various VCU sub-model libraries built based on Modelica and conduct closed-loop simulation tests to compare the actual vehicle state control results with the expected results;

[0094] Through the preset electrical signal interface module, all functional modules are attached Figure 4 The connections are made in the order of, wherein the input data of the sensor is replaced by the vehicle data collected in advance, and the real-time vehicle control strategy output by the VCU control is calculated and simulated by the input test case to see whether it is accurate.

[0095] The entire VCU control system model must ensure that there are no missing interfaces and that the output VCU control strategy can enable other electrical components of the vehicle to operate normally. Due to the particularity of the vehicle control schematic, the lack of an interface may cause the entire vehicle control schematic to be paralyzed. The method of functional decomposition modeling of the VCU control system based on vehicle parameters and interface requirements can effectively ensure the smooth operation of the VCU control system in the actual vehicle.

[0096] The technical solution of the present application is described in detail above in conjunction with the accompanying drawings. The present application proposes a model library construction method for a VCU control system of an unmanned vehicle based on Modelica, the method comprising: step 1, determining the vehicle parameters of the unmanned vehicle and the corresponding vehicle control schematic diagram of the VCU control system, and dividing the functional requirements of the VCU control system according to the vehicle control schematic diagram to determine the functional modules; step 2, determining the corresponding relationship between the input signal and the actual output control signal under different driving states of the unmanned vehicle, and combining the basic judgment module according to the corresponding relationship and the preset electrical signal interface module to establish a logic judgment module, wherein the input signal is a signal collected by the vehicle sensor and input to the VCU control system, and the actual output control signal is an actual control signal for switching between different driving states; step 3, establishing a signal interface according to the functional requirements of the VCU control system, connecting the signal interface with the corresponding logic judgment module, and establishing a functional module model of the functional module; step 4, according to the vehicle control schematic diagram, connecting the functional module models in sequence and performing closed-loop simulation tests to obtain the actual vehicle state control results, and comparing the actual vehicle state control results with the expected results to adjust the functional module models. The technical solution in this application solves the problems of incomplete configuration of basic vehicle parameters and missing vehicle interface functions in VCU control system modeling in related technologies.

[0097] The steps in this application can be adjusted in order, combined, and deleted according to actual needs.

[0098] The units in the device of the present application can be combined, divided and deleted according to actual needs.

[0099] Although the present application is disclosed in detail with reference to the accompanying drawings, it should be understood that these descriptions are merely exemplary and are not intended to limit the application of the present application. The scope of protection of the present application is defined by the appended claims and may include various modifications, alterations and equivalents made to the invention without departing from the scope and spirit of the present application.

Claims

1. A model library construction method for a VCU control system of an unmanned vehicle based on Modelica, characterized in that: The method includes: Step 1, determining the vehicle parameters of the driverless car and the corresponding vehicle control schematic diagram of the VCU control system, and dividing the functional requirements of the VCU control system according to the vehicle control schematic diagram to determine the functional modules; Step 2, determining the correspondence between the input signal and the actual output control signal under different driving states of the driverless car, and combining the basic judgment module according to the correspondence and the preset electrical signal interface module to establish a logic judgment module, Wherein, the input signal is a signal collected by a vehicle sensor and input to the VCU control system, and the actual output control signal is an actual control signal for switching between different driving states; Step 3, establishing a signal interface according to the functional requirements of the VCU control system, connecting the signal interface with the corresponding logic judgment module, and establishing a functional module model of the functional module; Step 4, according to the vehicle control principle diagram, the functional module models are connected in sequence and a closed-loop simulation test is performed to obtain an actual vehicle state control result, and the actual vehicle state control result is compared with the expected result to adjust the functional module model; The functional modules at least include: Motor controller module, energy management module, vehicle command module, state machine module, relay management module and system control monitoring module; In step 3, the function module modeling process of the state machine module specifically includes: Step 301, defining the upper state of the state machine module and the lower state included in the upper state, defining the number of input and output signal interfaces required by the state machine module, and establishing empty state modules with only input and output signal interfaces corresponding to the lower state one by one according to the preset electrical signal interface modules, wherein the upper state includes at least an initial state, an intermediate state, and a terminal state; Step 302, adding the corresponding logic judgment module to the empty state module, and sequentially connecting the interface of the empty state module with the logic judgment module to establish a model of the underlying state; Step 303, classifying the corresponding underlying state models according to the initial state, the terminal state and the corresponding underlying state, and connecting them through a preset electrical signal interface module to generate the initial state model and the terminal state model; Step 304, adding the corresponding logic judgment module and the model of the bottom state according to the trigger event requirements of the vehicle state change to generate the model of the intermediate state; Step 305 , connecting the model of the initial state, the model of the terminal state, and the model of the intermediate state through corresponding preset electrical signal interface modules to generate a functional module model of the state machine module.

2. The method for constructing a model library of a VCU control system of an unmanned vehicle based on Modelica as claimed in claim 1, characterized in that: The step 1 specifically includes: Step 11, determining the vehicle parameters, wherein the vehicle parameters at least include vehicle performance parameters and vehicle power parameters; Step 12, determining the vehicle control schematic diagram of the VCU control system according to the vehicle parameters; Step 13, determining the signal interface requirements of the VCU control system according to the vehicle control schematic diagram; Step 14: According to the signal interface requirements and the vehicle control schematic diagram, the functional requirements of the VCU control system are divided to determine the functional modules.

3. The method for constructing a model library of a VCU control system of an unmanned vehicle based on Modelica as claimed in claim 1, characterized in that: In step 3, the functional module modeling process of the energy management module specifically includes: Step 311, using the preset electrical signal interface module as an input and output interface, establishing a blank energy management module and a blank energy allocation strategy logic control module; Step 312, establishing a battery SOC estimation module based on the modified ampere-hour integration method, and establishing an energy distribution module according to the requirements of each output interface through a fuzzy logic control method; Step 313, fill the SOC estimation module and the energy distribution module into the blank energy distribution strategy logic control module, and connect the corresponding signal interface to generate the vehicle energy distribution strategy module; Step 314, adding the corresponding logic model between the input interface of the blank energy management module and the vehicle energy distribution strategy module to establish a complete energy management module.

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