JP2008084121A - Simulation system and simulation method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a simulation system capable of securing freedom of a simulator to be connected and performing setting operation of an environmental condition of a model program easily in establishing a simulation system of distributed type. <P>SOLUTION: The simulation system is provided with: a plurality of slave management devices SPC for managing environmental conditions of simulation in a simulator SM which executes prescribed simulation in association with a plurality of simulators SM; and a master management device MPC which is connected to the respective slave management devices SPC via a network and performs integration management of the environmental conditions of the simulation in the plurality of simulators SM via the slave management devices SPC. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a simulation system including a simulator that executes a predetermined model program, and a management device that manages the setting of the model program and its environmental conditions, and more particularly to a simulation system suitable for evaluating a vehicle control system. .

  In recent years, in order to reduce the time and cost required for product development and to improve the safety of product development, the actual software controlled for evaluation of embedded software developed in various fields. A simulation system is used in which the apparatus is simulated by a mathematical model program and calculated by a computer, and based on the result, characteristics can be confirmed and possible problems can be extracted.

  As such a simulation system, for example, in order to evaluate control software incorporated in an ECU (Electronic Control Unit) that electronically controls a vehicle, an ECU board comprising control system hardware in which an evaluation target program is incorporated, and an ECU A model program for simulating an engine system that is an example of a non-control system controlled by a board is incorporated, a simulator composed of controlled system hardware controlled by the ECU board, input / output information of the model program, It has been proposed to build a simulation unit with a management device consisting of a host computer that manages the setting and execution of environmental conditions.

  In addition, control system software that simulates the ECU itself, which is control system hardware incorporating control software, a simulator composed of controlled system software that simulates the controlled system hardware itself, and the model program It has also been proposed to construct a simulation unit with a management device composed of a host computer that manages the setting and execution of input / output information and environmental conditions.

  The former simulator is generally referred to as HILS (Hardware In the Loop Simulation), and the latter simulator is generally referred to as SILS (Software In the Loop Simulation).

  As a publicly known technique related to the present invention, Patent Document 1 discloses a software and hardware simulation system that operates on the same OS, and Patent Document 2 discloses a personal computer program and simulator hardware on a CPU. A configuration connected on a computer simulator board is disclosed, and Patent Document 3 discloses a verification system for supporting the advance development of a microcomputer that can efficiently verify a program when a real device and a virtual device are used as peripheral devices. Has been.

JP 2002-175344 A JP 2001-331346 A JP 2003-316603 A Shuzo Tanaka et al. “Control Software Development by All-Soft Simulation” Fujitsu Ten Technical Report, June 2006, pp. 28-33

  When evaluating development software using the simulation system described above, multiple simulators transplanted with different model programs are connected in parallel, and parallel computation is performed at a set computation cycle. A distributed simulation system that realizes the model is constructed, and comprehensive evaluation is performed when the program to be evaluated is installed in the system.

  Conventionally, when such a distributed simulation system is constructed, as shown in FIG. 1, a plurality of simulators SM for simulating each functional block of an evaluation target apparatus are provided on one host computer PC as a management apparatus. A plurality of model programs MP to be ported to each simulator SM are connected to the host computer PC in the network, and are managed in units of simulators as software resources in the user folder 1 of the memory M, and the model programs MP for each simulator SM A single simulation information management area A for setting environmental conditions such as input / output conditions and operation setting screens is set, and environmental conditions are set on the simulation information management area A for each corresponding simulator SM. SM model blog Beam and environmental conditions have been configured to be downloaded.

  That is, after setting and downloading an environmental condition in a single simulation information management area A for a certain simulator SM, setting and downloading the next environmental condition in the simulation information management area A for the next simulator SM It was necessary to repeat the operation.

  Here, the environmental conditions are the setting conditions such as input / output information between the host computer PC and the GUI (Graphical User Interface) for controlling the simulation from the display unit of the host computer PC when the simulation is executed. A GUI setting condition is a graphic model that displays on the GUI the type of operation switch and meter MT displayed on the GUI for setting the calculation conditions for the simulator, and the control data obtained from the simulator. This refers to selection of GM.

  In another configuration, as shown in FIG. 2, a plurality of simulators SM are network-connected to one host computer PC as a management apparatus, and a plurality of simulators SM to be ported to each simulator SM are connected to the host computer PC. The model program MP is managed as a software resource in the user folder 1 of the memory M for each simulator SM, and simulation information management for setting environmental conditions such as model program input / output conditions and operation setting screens for each simulator SM The area A is set individually, and after setting the environmental conditions of the simulation information management area A for each corresponding simulator SM, the model program MP and the environmental conditions are downloaded simultaneously to each simulator SM.

  The simulation system described above is a simulation that is required by operating the operation switch, meter, etc. displayed on the operation screen of the host computer with a pointing device such as a mouse after the model program and environmental conditions are downloaded to the simulator. Is executed.

  However, in the case of the former, since the simulation information management area is configured to be shared by a plurality of simulators, the environment conditions of the plurality of simulators cannot be set or viewed at a time on the management apparatus side, Alternatively, there is a problem that the browsing operation is troublesome and time consuming.

  In the case of the latter, the amount of simulators that can be connected at the same time is limited due to the limited capacity of the simulation information management area because the data capacity is very large even under the environmental conditions of one simulator. There was a problem and the problem that it was necessary to unify the operating system of each simulator.

  For example, when building a vehicle model using the above simulation system, functional simulators such as a vehicle engine and a mission are simulated by each simulator. Control software for controlling such functional blocks is evaluated. In this case, although it is necessary to use the HILS system for the accurate and strict evaluation for the functional block to be evaluated, either the HILS system or the SILS system may be used for the functional block other than the evaluation target.

  However, the SILS system has a problem that it cannot be incorporated due to a mismatch in calculation accuracy or speed depending on simulation conditions.

  In addition, the HILS system generally requires a number of man-hours for development and cannot be easily obtained. If the ECU board, which is the control system hardware, is changed, it is necessary to replace the controlled system hardware and rebuild the system accordingly. In addition, since the system cannot be constructed when the corresponding ECU board or controlled hardware cannot be prepared, there is also a problem that the system cannot be constructed flexibly unless the existing resources are managed accurately.

  In view of the above-described problems, the object of the present invention is to secure a degree of freedom of a connected simulator and to easily set an environment condition of a model program when constructing a distributed simulation system. The purpose is to provide a system.

  In order to achieve the above-described object, the characteristic configuration of the simulation system according to the present invention includes a plurality of slave management devices that manage simulation environmental conditions in a simulator that executes a predetermined simulation in correspondence with a plurality of simulators, A master management device is provided that is connected to a slave management device over a network and that collectively manages simulation environmental conditions in a plurality of simulators via the slave management device.

  According to the above configuration, if the environmental conditions of each model program are set collectively via the master management device, the environmental conditions are automatically set from the master management device to each simulator via each slave management device. In addition, the environmental conditions of a plurality of simulators can be browsed collectively from the master management device. That is, it is not necessary to set a large-capacity simulation information management area in each slave management apparatus, and a flexible simulation system can be constructed.

  As described above, according to the present invention, when a distributed simulation system is constructed, a simulation system capable of ensuring the freedom of a connected simulator and easily setting an environmental condition of a model program. Can now be offered.

  Hereinafter, a case where the present invention is applied to a simulation system that evaluates control software incorporated in an ECU that electronically controls a vehicle will be described as an example.

  As shown in FIG. 3, the simulation system includes a pair of simulator SM as a node that executes a predetermined model program MP and a slave management device (slave host computer) SPC that manages the setting of the model program MP and its environmental conditions. A plurality of simulation units SU connected at a time, each slave management device SPC, and a master management device (master host computer) MPC connected by a network via a LAN.

  Each simulation unit SU is separated from the system, and a model program MP corresponding to the connectable simulator SM is divided into individual folders in the user folder 1 of the memory M of the slave management device SPC so that the simulation can be performed independently. In the simulation information management area A divided into the memory M, environmental conditions corresponding to the connected simulator SM can be set and stored.

  The above-described system is configured such that a simulator unit SU on which control software to be evaluated is mounted is first evaluated as a single unit, and then connected to the system for comprehensive evaluation.

  The environmental conditions are input / output information with the slave management device SPC when the simulation is executed, that is, the type, unit, accuracy, and data of data necessary for the simulation execution and evaluation with the slave management device SPC. Is a setting condition that defines the array information, and a GUI (Graphical User Interface) setting condition for controlling the simulation from the display unit of the slave management device SPC. The GUI setting condition is a calculation condition for the simulator SM. To select the graphic model GM for displaying control data obtained from the simulator SM on the GUI, and the like.

  For example, when the simulator SM simulates an engine, input data such as engine start key information, accelerator opening information, fuel information, engine speed, fuel injection amount, travel speed, exhaust gas monitor information, oil Output data types such as temperature information, unit, accuracy, data arrangement, etc. correspond to input / output information setting conditions, engine start switch, accelerator switch, shift switch, etc. correspond to operation switches, tachometer, speed A meter or the like corresponds to the meter M, and a trend graph of the engine speed corresponds to a graphic model.

  The slave management device SPC is provided with an environmental condition setting means for setting an environmental condition by an operator's setting operation and storing it in the simulation information management area A, and an operation displayed on the display unit based on the set environmental condition. Operation control means is provided for controlling the execution of the simulation by operating a switch and inputting control data and process data input from the simulator SM based on the set environmental conditions to display the meter MT and a graph. .

  The master management device MPC includes a plurality of model programs MP managed by each slave management device SPC and a database DB as a management means for managing overall environmental conditions. A new slave management device SPC is connected to the system. Then, the model program MP and environmental conditions are uploaded from the slave management apparatus SPC and stored in the database DB.

  In the database DB, as shown in FIG. 8, model programs for simulating parts such as steering, mission, brake, engine, and motor, which are each functional block of the vehicle, are managed for each vehicle type and model, and for each vehicle type and model. It is managed together with attribute data that can identify a model program that can be mounted, and simulator information to which the model program can be ported. Note that the model program managed in the database DB is not always managed as a set for each vehicle type or model, and each model program may be managed for each part. There is a case where there is no model program for, or some parts can be used in multiple car models.

  Furthermore, in the master management apparatus MPC, environmental conditions corresponding to the model program MP executed by each simulator SM are set collectively by the operator's setting operation, and stored in the simulation information management area B partitioned in the database DB. Environmental condition setting means is provided, and browsing means for displaying the stored environmental conditions collectively on the display unit of the master management apparatus MPC is provided. In the environmental condition setting means, in addition to the environmental conditions set by the slave management device described above, the input / output data related to each other is also set between the simulator units.

  The environmental condition set and input to the master management apparatus MPC is downloaded to each slave management apparatus SPC via the LAN, and is reflected in its own simulation information management area A by the environmental condition setting means of each slave management apparatus SPC. It is configured.

  The master management device MPC controls each slave management device SPC by operating an operation switch displayed on the display unit based on the set environmental conditions, and controls the execution of each simulation. Arithmetic control means for inputting control data and process data input from the simulator SM via the slave management device SPC based on the conditions and displaying the meter MT and a graph is provided.

  Therefore, each simulator can be controlled by operating the operation switch displayed via the GUI of the master management device MPC, and the result is displayed via the GUI of the master management device MPC. Yes.

  The environmental condition setting means provided in the master management device MPC is provided with automatic input / output determination means for ensuring the consistency of environmental data set corresponding to the connected simulator unit, and a certain simulator SM is required for calculation. The data type, unit, precision, data arrangement information, and the like are matched so that the data output from the other simulator SM is reliably input.

  The simulator SM connectable to the system includes an ECU (electronic control unit) as control system hardware in which an evaluation target program is incorporated, and controlled system hardware in which a model program is incorporated and controlled by the ECU, that is, an engine The HILS system as a hardware simulator composed of hardware blocks that simulate the mission and the mission, or the control system software that simulates the ECU and the controlled system software that simulates the controlled system hardware on one computer It is composed of a SILS system as a software simulator to be realized.

  When HILS systems or SILS systems having different simulation levels are mixed in the simulator SM connected to the system in the master management apparatus MPC, an appropriate simulator is selected from the resources stored in the database DB so that the simulation levels are matched. Simulator selecting means for selecting is provided.

  Furthermore, when HILS systems and SILS systems having different simulation levels coexist, the environmental conditions of each simulation model are automatically set by the above input / output automatic determination means so that the respective input / output data are matched.

  For example, as shown in FIG. 4, the HILS system includes a ROM that stores control software that is actually mounted on the vehicle, a CPU that executes the software, a RAM that is used as a working area, an input / output circuit, and the like. ECU, which is connected to the ECU through a harness, a simulator SM in a narrow sense for simulating a control target such as an engine, and a slave management device for controlling the simulator SM. In the present invention, the ECU and the simulator SM are described as broad simulators.

  As shown in FIG. 5, the simulator SM of the HILS system includes a model calculation processing unit 11 in which a simulation model SM is installed and executes model calculation, an I / F unit 16 connected to the ECU via a harness, model calculation An I / O unit 12 that converts a signal between a logical level and a physical level between the processing unit 11 and the I / F unit 11 and a CPU board 10 on which an operating system that controls the simulator is installed are connected via a high-speed bus. Connected and configured.

  The CPU board 10 is connected to the slave PC, manages the simulator SM, and transplants the simulation model SM sent from the slave PC to the model arithmetic processing unit 11 and sets necessary environmental conditions in each unit.

  The shared memory board 13 provided in the I / O unit 12 is configured to be able to input and output shared data with other simulators via a high-speed bus, and to be able to communicate between the simulators via the shared memory board 13. ing. For example, a CAN bus, which is a network connecting ECUs, is configured to be able to send and receive data to and from an ECU connected to another simulator SM via a CAN board 17.

  In other words, the electrical signal output from the ECU is received by the I / F unit 16 and is processed by a vehicle model that operates on a high-performance CPU, and the processing result is converted again into an electrical signal by the I / F unit 16. It is configured as a real-time simulator that feeds back to the ECU.

  For example, as shown in FIG. 6, the SILS system includes a control software that is actually mounted on a vehicle and a simulated ECU that models a hardware environment in which the software is executed (denoted as “microcomputer simulator” in the figure). )), And a software simulator that models a hardware environment composed of the model arithmetic processing unit 11, the I / F unit 16, the I / O unit 12, and the CPU board 10 of the simulator of the HILS system. A slave management device SPC that is realized as a simulator SM realized on a computer and controls the simulator SM is connected.

  As shown in FIG. 7, on a CPU board 20 of one computer operating on a predetermined operating system (OS), a control system model 21 having a plurality of modules for executing control software, and control by the control software A controlled system model 23 having a plurality of simulated operation modules, a shared memory 25 for exchanging input / output data between the controlled system model 21 and the controlled system model 23, and the controlled system model 21 or the controlled system model 23. Is generated in relation to the event, and the corresponding module of the control system model 21 or the controlled system model 23 is activated, and the activation time of the event is set and managed based on the system timer 225. The control system model 21 or the controlled system System management means 23 for controlling execution of the model 23 is provided.

  The system management unit 23 operates the control system model 21 or the non-control system model 23 based on the data on the shared memory 25 written from the I / O drivers 27 and 28 of the control system model 21 or the non-control system model 23. Events that occur in a time series based on the time information managed by the system timer 24 are written to the shared memory 25, and the control system model 21 or non-control based on the events written to the shared memory 25 The system model 23 is configured as an event-driven simulator that executes predetermined processing.

  In the above-described HILS system and SILS system simulator SM, a plurality of simulators having different levels are constructed. In the HILS system, there are two types of simulators: a simple HILS that can only support real time and faithfully reproduce only the external specifications (input / output) and a detailed HILS that can only support real time and faithfully reproduce the operation of the actual ECU. The level information is added to each model program MP.

  In the SILS system, the time can be increased and ultra-simple SILS that faithfully reproduces only the register input / output of the microcomputer, and the simple SILS that can cope with real time and faithfully reproduce only the instruction set of the microcomputer can be supported only under real time. There are four types of simulators: detailed SILS that faithfully reproduces only the external specifications (input / output) of the microcomputer, and ultra-detailed SILS that can reproduce only the internal signals of the microcomputer that can only deal with real time or less. The level information is added to the program MP.

  Each level information includes the simulation accuracy P1, the signal measurement accuracy P2, the simulation speed P3, the number of input / output signals P4 between simulators, the number of communication signals (such as CAN) P5 between simulators, and the communication data amount P6 between simulators. Simulation characteristic data is included.

  The simulator selection means provided in the master management device MPC is configured to select the simulator having the highest simulation level among the simulators that can realize the simulation speed requested by the operator, and corresponds to the selected simulator. The simulation is controlled by the arithmetic control means.

  A plurality of simulation units including a simulator SM that executes a predetermined model program and a slave management device SPC that manages the setting of the model program and its environmental conditions are connected to the above-described master management apparatus MPC, and environmental condition setting is performed. The procedure by which the environmental conditions are matched by the means and the simulation system is constructed will be described based on the operation explanatory diagrams of FIGS.

  When the simulation unit SU is connected to the master management device MPC, and each slave management device SPC and the simulator SM are powered on, a startup screen registered in advance on the display unit of the slave management device SPC is displayed.

  Subsequently, when the master management device MPC is turned on, the main program is activated and user authentication is performed. Upon completion of the authentication, the system configuration in which the target user was last opened, that is, the simulation used for the simulation. The standard environmental condition data corresponding to the unit SU is expanded in the simulation information management area B of the master management device MPC, and the standard environmental conditions set in each slave management device SPC are transferred from the user folder 1 to the slave management device SPC. In the simulation information management area A.

  When the simulation unit SU is connected for the first time, the simulation model and environmental conditions stored in the user folder 1 of the slave management device SPC are uploaded to the database DB, and at the second and subsequent connections, the simulation information management area of the slave management device SPC The environmental conditions expanded in A and the contents of the environmental conditions registered in the database DB in the past are compared. If they are different, the simulation model and the environmental conditions stored in the user folder of the slave management device SPC are stored in the database DB. Uploaded, the past simulation model and environmental conditions are updated to the new simulation model and standard environmental conditions.

  Next, when the operator operates the master management device MPC to set the environmental conditions for the simulation information management area of the master management device MPC in order to execute the target simulation, the simulation is stored in its own database DB. The arithmetic control unit of the master management device MPC is started after the update processing is performed to the set environmental condition and the environmental condition of the slave management device SPC. The arithmetic control unit of the slave management device SPC It is activated. That is, the environmental conditions corresponding to each model program are set so as to be consistent between the master management device MPC and the slave management device SPC.

  When the arithmetic control means of the slave management device SPC is activated, the initial setting of the simulation is started. Thereafter, the data manager of the master management device MPC is activated by the operator, and the input to each slave management device SPC set in the environmental conditions is started. A plurality of sampling label data as output data is read from the database DB and expanded in the master management device MPC, and the communication state with the simulator SM connected via each slave management device SPC is confirmed, and normal If so, the sampling label data is transferred to the simulator SM connected via each slave management device SPC. Thereby, the setting of each simulation unit SU is completed, and the simulation is started.

  With the above-described procedure, the model program and the environmental condition data are adjusted so that the simulation is possible for the system including the master management device MPC and the simulation unit SU connected to the master management device MPC.

  The procedure for constructing the simulation system by specifically selecting the optimum simulation unit SU by the operation of the operator and the simulator selection means provided in the master management apparatus MPC will be described below based on the flowchart shown in FIG. .

  When a simulation model for executing control software incorporated in the ECU to be evaluated is selected and input to the master management apparatus MPC, next, simulation accuracy P1, signal measurement accuracy P2, and simulation speed P3 are input by the simulator selection means. Is required to do. For example, when evaluating the control software for the brake ECU, at least the brake model is selected as the HILS system, and as the other simulators such as the engine and the mission, either the HILS system or the SILS system is selected.

  When the operator inputs the simulation accuracy P1 (S1), a simulation model satisfying the required accuracy is searched from the database DB based on the simulation characteristic data, and candidates for each simulator are extracted. When a candidate simulator does not exist in the resource, a message to that effect is displayed and prompts to reset the required accuracy (S2).

  In other words, when selecting a simulator that simulates a node from existing simulators that can simulate a node, the simulator with the highest simulation accuracy is selected from the simulators that can achieve the simulation speed required by the node. To behave.

  When a candidate simulator is extracted by lowering the required accuracy, the signal measurement accuracy P2 is input (S3). Similarly, a simulation model satisfying the required accuracy is searched from the database DB based on the simulation characteristic data, candidate simulators are extracted, and when a candidate simulator does not exist in the resource, a message to that effect is displayed and the request You are prompted to reset the accuracy (S4).

  Next, when the simulation speed P3 is input (S5), similarly, a simulation model satisfying the required accuracy is searched from the database DB based on the simulation characteristic data (S6).

  For each of the candidate simulators thus narrowed down, the number of input / output signals P4 between simulators, the number of communication signals (CAN, etc.) P5 between simulators, and the amount of communication data P6 between simulators as shown in FIG. A simulator necessary for the simulation is evaluated based on the priority order data for (S7), and the simulation level is automatically selected (S8).

  Here, the priority order data includes the number of input / output signals P4 between simulators and the number of communication signals (CAN, etc.) between simulators for a simulator that satisfies the set simulation accuracy P1, signal measurement accuracy P2, and simulation speed P3. The degree of matching for each of P5 and the amount of communication data P6 between simulators is data set in advance by the user. The degree of matching is a value obtained by weighting whether or not the number of input / output signals, the number of communication signals, and the amount of communication data between the simulators are within appropriate ranges with respect to the requested simulation level.

  That is, the simulator selecting means is configured such that when a plurality of candidate simulators are extracted in step S6, the simulator having the highest simulation level is automatically selected based on preset priority data. ing. Here, when the SILS system and the HILS system coexist in the resource, the priority order is set so that the HILS system is selected with priority over the SILS system.

  In step 7, the priority order data may be displayed on the operation screen, and the operator may manually select each simulator based on the priority order data.

  When each simulation unit SU constituting the system is selected in this way, there is an automatic input / output determination means for ensuring the consistency of standard environmental data set corresponding to the connected simulator unit SM. The data type, unit, accuracy, data arrangement information, etc. are matched so that the simulator SM is the input data required for the operation and the data output from the other simulator SM is input reliably. Environmental condition data corresponding to the simulation system is registered in the database DB, and the environmental condition data of each slave management device SPC is updated. That is, the environmental conditions of each simulation model are automatically set so that the respective input / output data matches.

  The requested simulation is executed for the simulation system constructed as described above, and a predetermined control program to be evaluated is evaluated.

  As described above, according to the simulation system of the present invention, the environmental conditions of each slave management apparatus SPC are managed by the master management apparatus MPC, and the environmental conditions in each slave management apparatus SPC are unified by the master management apparatus MPC. It is possible to change settings or view them automatically, and to manage the simulations centrally. Furthermore, since the set environmental conditions are also managed by the slave management apparatus SPC, the slave management apparatus SPC can be separated from the system and simulated alone, or can be incorporated into the system and integratedly simulated.

  In the above-described embodiment, the example in which the simulation system according to the present invention is constructed as a simulation system for evaluating the control software incorporated in the ECU that electronically controls the vehicle has been described. The present invention is not limited to a simulation system that evaluates control software incorporated in an electronically controlled ECU, and can be applied to control systems for various electronic devices and control systems for chemical plants.

  The embodiment described above describes an example for realizing the present invention, and the specific configuration of each part should be appropriately changed and designed according to the system to be constructed as long as the effects of the present invention are achieved. Is possible.

Illustration of a simulation system showing a conventional example Illustration of a simulation system showing a conventional example Explanatory drawing of the simulation system by this invention Conceptual diagram of HILS system HILS system configuration diagram Conceptual diagram of SILS system SILS system configuration diagram Illustration of simulation model managed by host management device Operation explanatory diagram of the simulation system according to the present invention Operation explanatory diagram of the simulation system according to the present invention The flowchart which shows the selection procedure of the simulator by this invention Explanatory drawing of the priority order data showing the selection criteria of the simulator according to the present invention

Explanation of symbols

1: User folder A, B: Simulation information management area DB: Database MP: Model program MPC: Master management device SPC: Slave management device SM: Simulator GUI: Graphical user interface

Claims (5)

  A plurality of slave management devices that manage simulation environmental conditions in a simulator that executes a predetermined simulation are provided in correspondence with a plurality of simulators, and are connected to each slave management device over a network, and a plurality of simulators are connected via the slave management device. A simulation system comprising a master management device for comprehensively managing the environmental conditions of simulation in Japan.   The master management device includes a management unit that collectively manages the environmental conditions of the simulator managed by each slave management device, and the management unit needs to be set when the environmental conditions of the entire simulation system are set. 2. The simulation system according to claim 1, wherein an instruction for setting an environmental condition is given to a slave management apparatus.   The master management device instructs the slave management device that manages the environmental conditions for the connected simulator to set the environmental conditions so that it matches the environmental conditions for the other connected simulators. The simulation system according to claim 1, wherein:   A simulation method for executing simulation of the simulation target system by connecting a plurality of simulators via a network and simulating a plurality of nodes constituting the simulation target system with each of the selected simulators. When selecting a simulator to be simulated from existing simulators that can simulate the node, a simulation that selects the simulator with the highest simulation accuracy among the simulators that can realize the simulation speed requested by the node. Method.   When a simulator that simulates the node is selected from existing simulators that can simulate the node, a hardware simulator configured by hardware is selected in preference to a software simulator configured by software. The simulation method according to claim 4, wherein: